JP7607221B2 - Rice cooker - Google Patents

Description

This disclosure relates to a rice cooker.

A known conventional rice cooker is a fully automatic rice cooker that integrates a series of processes including rice storage, washing, and cooking. A conventional rice cooker includes a rice storage section for storing rice, a rice washing space for washing the rice, and a rice cooking section (see Patent Document 1).

Japanese Patent Application Publication No. 5-220047

Conventional rice cookers require water supply from an external water source such as a water main, so installation requires construction work for water supply and drainage, and the cooker must be installed near an external water source such as a water main. As a solution, it is possible to place a water container for storing water inside the housing of the rice cooker. In this case, there is a problem of measuring the amount of water stored in the water container.

To solve the above problem, it is conceivable to provide a pressure sensor in the water supply pipe for sending water from the water container to the rice cooking section or in the water container. The pressure detected by the pressure sensor varies depending on the water level in the water container. This makes it possible to measure the amount of water stored in the water container.

However, when the amount of water stored in the water container is small, when the water container is attached, or when water remaining in the water supply pipe is returned to the water container after water is supplied to the rice cooking unit, air may flow through the water supply pipe. The presence of this air may adversely affect the detection accuracy of the pressure sensor. For example, water and air may be mixed in the water supply pipe when the water container is attached to the housing. In addition, when water remaining in the water supply pipe is returned to the water container after water is supplied to the rice cooking unit, air bubbles may accumulate in the opening connecting the water container and the water supply pipe. Since the shapes, sizes, numbers, etc. of air bubbles vary, the presence of air bubbles may affect the detection accuracy of the pressure sensor. In addition, water droplets may remain on the inner surface of the pipe near the pressure sensor. In this case, liquid and gas may be mixed inside the pipe, which may affect the detection accuracy of the pressure sensor.

Therefore, the object of the present disclosure is to solve the above problem and to provide a rice cooker that can maintain good accuracy in detecting the amount of water stored in the water container and the amount of water being delivered.

In order to achieve the above object, the present disclosure is configured as follows.
A rice cooker according to one aspect of the present disclosure includes:
A pot and
a water container for storing water therein, the water container having a first communication port and a second communication port for connecting the inside of the water container with the outside;
a first pipe connected to the first communication port to communicate with the inside of the water container;
a second pipe connected to the second communication port and opening toward the inside of the pot, thereby communicating between the inside of the water container and the inside of the pot;
a water pump provided in the second pipe to move water in the second pipe;
a third tube branching upward from the first tube, the third tube having a sealed air pocket formed therein when the first tube is at least partially filled with water;
A pressure sensor is provided in the third pipe and detects the pressure inside the third pipe.

According to the present disclosure, it is possible to maintain good accuracy in detecting the amount of water stored in the water container and the amount of water being delivered.

FIG. 1 is a perspective view showing the appearance of a rice cooker according to a first embodiment. FIG. 2 is a perspective view showing the appearance of the rice cooker with the lid of the housing open. FIG. 2 is a perspective view showing the appearance of the rice cooker with the lid of the rice container open. FIG. 2 is a perspective view showing the internal structure of the rice cooker of FIG. 1 . FIG. 2 is a perspective view showing the internal structure of the rice cooker of FIG. 1 . FIG. 4 is a perspective view showing the water container and the water conveying unit excluding the cover plate. FIG. 4 is a plan view showing the water container and the water conveying unit without the cover plate. FIG. 4 is a perspective view showing a water container including a cover plate and a water supply unit. FIG. 4 is a plan view showing the water container including the cover plate and the water supply unit. 8 is a cross-sectional view showing the AA cross section of FIG. 7. FIG. FIG. 4 is a schematic diagram showing a water container, a water supply unit, and a pan. FIG. 2 is a block diagram illustrating a hardware configuration of a rice cooker. 1 is a flowchart showing an example of a rice cooking process. 11 is a flowchart showing an example of a water conveying process. 11 is a flowchart showing an example of a circulation process during temperature detection. 11 is a flowchart showing an example of a circulation process during ultraviolet irradiation. FIG. 11 is a schematic diagram showing a water container, a water supply unit, and a pot in a modified example of the rice cooker according to the first embodiment. FIG. 11 is a schematic diagram showing a water container, a water supply unit, and a pot in a rice cooker according to a second embodiment. FIG. 11 is a schematic diagram showing a water container, a water supply unit, and a pot in a rice cooker according to a third embodiment. FIG. 13 is a schematic diagram showing a water container, a water supply unit, and a pot in a modified example of the rice cooker according to the third embodiment.

A rice cooker according to one aspect of the present disclosure includes:
A pot and
a water container for storing water therein, the water container having a first communication port and a second communication port for connecting the inside of the water container with the outside;
a first pipe connected to the first communication port to communicate with the inside of the water container;
a second pipe connected to the second communication port and opening toward the inside of the pot, thereby communicating between the inside of the water container and the inside of the pot;
a water pump provided in the second pipe to move water in the second pipe;
a third tube branching upward from the first tube, the third tube having a sealed air pocket formed therein when the first tube is at least partially filled with water;
A pressure sensor is provided in the third pipe and detects the pressure inside the third pipe.

According to this configuration, when the water container and the first communication port are connected, the water in the water container flows into the first tube, and the air in the first tube is discharged into the water container. This allows the air in the first tube to be replaced with water. When at least a portion of the first tube is filled with water flowing from the water container, the inside of the third tube becomes an enclosed space filled with gas. The pressure sensor detects the pressure in the third tube. In this case, the smaller the amount of water stored in the water container, the smaller the detected pressure. Therefore, the amount of water stored in the water container can be measured based on the pressure detected by the pressure sensor.

According to this configuration, the pressure sensor detects the pressure of the gas. In other words, a pressure sensor for gas can be used. This makes it possible to increase the resolution of the pressure detected by the pressure sensor. In other words, it is possible to increase the detection accuracy of the pressure sensor.

In the second pipe, which is the water flow path between the water container and the pot, water moves during the process of sending water to the pot and the process of returning water remaining in the second pipe to the water container. At this time, there is a possibility that air will enter the second pipe mixed with the water. With this configuration, a pressure sensor is provided in a third pipe connected to a first pipe that is different from the second pipe. In the first pipe, there is no water movement like in the second pipe. Therefore, the possibility of water and air entering the first pipe mixed together is lower than the possibility of water and air entering the second pipe mixed together. This makes it possible to reduce the possibility that the detection accuracy of the pressure sensor will be affected by the mixture of water and air. As a result, the detection accuracy of the pressure sensor can be maintained at a good level.

In one aspect of the present disclosure, a rice cooker includes:
The second pipe may be connected to the first pipe at a branching position between the water pump and the pot,
The first pipe and the second pipe between the branching position and the second communication port may form a circulation flow path.

According to this configuration, the air in the circulation flow path can be sent to the water container by driving the water pump to circulate the water in the circulation flow path. This replaces the air in the circulation flow path with water, filling the circulation flow path with water. Here, the pressure sensor detects the pressure of the gas in the third tube that communicates with the circulation flow path. This makes it possible to reduce the possibility that the detection accuracy of the pressure sensor will be affected by the mixture of water and air. As a result, the detection accuracy of the pressure sensor can be maintained at a good level.

With this configuration, a part of the flow path in the second pipe constitutes the circulation flow path. Therefore, compared to a configuration in which the flow path in the second pipe is a flow path separate from the circulation flow path, the effect of the rise in internal pressure that occurs when the water container is connected to the first pipe and the second pipe can be reduced while keeping the space required to form the water flow path the same.

A rice cooker according to one aspect of the present disclosure includes:
a circulation on-off valve provided in the first pipe for opening and closing a flow path in the first pipe;
a water supply valve provided between the branching position in the second pipe and the pot, for opening and closing a flow path in the second pipe;
A control unit that controls the operation of the water pump and controls the opening and closing of the water supply valve and the circulation valve may further be provided.
The control unit is
The water supply valve may be closed and the circulation valve may be opened, and then the water supply pump may be driven to circulate the water contained in the water container in the circulation flow path, and then the water supply valve may be opened and the circulation valve may be closed, and then the water supply pump may be driven to supply the water contained in the water container to the pot.

According to this configuration, the water in the water container is circulated in the circulation flow path before being sent to the pot. As described above, by circulating the water in the circulation flow path, the air in the circulation flow path is replaced with water, so the detection accuracy of the pressure sensor can be maintained at a good level. In other words, according to this configuration, the water in the water container can be sent to the pot with good detection accuracy of the pressure sensor. Therefore, the amount of water in the water container and the amount of water lost in the water container due to the water being sent to the pot can be detected with high accuracy.

In one aspect of the present disclosure, a rice cooker includes:
The circulation on-off valve may be provided between a connection position of the first pipe with the third pipe and the branching position.

According to this configuration, the circulation valve is provided between the connection position of the first pipe with the third pipe and the branching position. Therefore, by closing the circulation valve, the third pipe can be separated from the path through which the water supply pump sends water from the water container to the pot. As a result, the pressure sensor can be detected while the water supply pump is operating. In other words, changes in the amount of water can be detected linearly.

A rice cooker according to one aspect of the present disclosure includes:
a fourth pipe branching off from the second pipe between the water supply pump and the water supply on-off valve in the second pipe or between the circulation on-off valve and the branching position in the first pipe;
The device may further include an air pump provided in the fourth tube, the drive of which is controlled by the control unit to send air from the outside to the first tube and the second tube via the fourth tube,
The control unit may drive the air pump while the water pump is stopped to send air to the first pipe and the second pipe.

With this configuration, when the air pump is driven, the air sent by the air pump pushes the water in the first tube or the water in the first tube and the second tube back into the water container. This reduces water leakage from the first tube and the second tube when the water container is removed from the rice cooker housing.

In one aspect of the present disclosure, a rice cooker includes:
The control unit may close the water supply on-off valve and open the circulation on-off valve when driving the air pump.

With this configuration, the water supply valve is closed when the air pump is driven. Therefore, when the air pump is driven, the water in the second pipe can be prevented from being sent to the pot by the air sent by the air pump, and the water in the second pipe can be returned to the water container.

According to this configuration, the circulation on-off valve is opened when the air pump is driven. Therefore, when the air pump is driven, the air sent by the air pump can return the water in the first tube and the second tube to the water container via the circulation flow path. This can reduce water falling from the first communication port and the second communication port when the water container is removed.

A rice cooker according to one aspect of the present disclosure includes:
The device may further include a temperature detection unit that detects water temperature or air temperature and outputs temperature information to the control unit.
When the temperature information is lower than a predetermined set temperature, the control unit may close the water supply valve and open the circulation valve, and then drive the water supply pump to circulate the water contained in the water container through the circulation flow path.

If the temperature of the water in the water container is low, there is a risk that the water will freeze. With this configuration, when there is a risk that the water will freeze, the control unit drives the water pump to circulate the water in the circulation flow path. This reduces the possibility of the water freezing as described above.

A rice cooker according to one aspect of the present disclosure includes:
The water supply device may further include an ultraviolet ray irradiation unit that is controlled by the control unit to irradiate ultraviolet rays toward the water contained in the water container,
When driving the ultraviolet irradiation unit to irradiate ultraviolet rays, the control unit may close the water supply valve and open the circulation valve, and then drive the water supply pump to circulate the water contained in the water container in the circulation flow path.

By irradiating the water in the water container with ultraviolet light, the proliferation of bacteria in the water in the water container can be suppressed. Here, when the water in the water container is stationary, the ultraviolet light irradiated by the ultraviolet light irradiating unit only hits the surface of the water in the water container. With this configuration, when the ultraviolet light irradiating unit irradiates ultraviolet light, the control unit drives the water pump to circulate the water contained in the water container in the circulation flow path. This causes the water in the water container to move, and the water located on the surface is replaced. Therefore, the ultraviolet light irradiated by the ultraviolet light irradiating unit can hit many parts of the water in the water container. As a result, the proliferation of bacteria in the water in the water container can be suppressed more effectively than with a configuration in which the water is not circulated.

In one aspect of the present disclosure, a rice cooker includes:
One end of the first pipe may be connected to the first communication port,
The other end of the first tube may be closed.

According to this configuration, when the water container and the first communication port are connected, the water in the water container flows into the first tube, and the air in the first tube is discharged into the water container. This allows the air in the first tube to be replaced with water. According to this configuration, one end of the first tube is connected to the first communication port, and the other end of the first tube is closed. This reduces the flow of water in the first tube, reducing the possibility of water and air mixing and entering the first tube. As a result, the detection accuracy of the pressure sensor can be maintained at a good level.

In one aspect of the present disclosure, a rice cooker includes:
One end of the first pipe may be connected to the first communication port,
The other end of the first tube may be open to the atmosphere.

With this configuration, the inside of the first tube can be maintained at atmospheric pressure. With this configuration, the other end of the first tube is open to the atmosphere. Therefore, when the water container and the first communication port are connected, the water in the water container can easily flow into the first tube. Therefore, the air in the first tube can easily be discharged into the water container. This makes it easy to replace the air in the first tube with water.

A rice cooker according to one aspect of the present disclosure includes:
The device may further include an atmosphere on-off valve for opening and closing a flow path within the first pipe, between the other end of the first pipe and a connection position of the first pipe with the third pipe.

According to this configuration, by closing the atmospheric on-off valve, the flow of water in the first pipe can be reduced. This reduces the possibility of water and air mixing and entering the first pipe. On the other hand, by opening the atmospheric on-off valve, the pressure in the first pipe can be maintained at atmospheric pressure. Therefore, when the water container and the first communication port are connected, the water in the water container can easily flow into the first pipe. Therefore, the air in the first pipe can easily be discharged into the water container. This makes it easy to replace the air in the first pipe with water.

In one aspect of the present disclosure, a rice cooker includes:
The water container may be provided with a third communication port that communicates the inside of the water container with the outside.
The first pipe may be connected to the first communication port and the third communication port to form a circulation flow path,
A rice cooker according to one aspect of the present disclosure includes:
The water circulation system may further include a circulation pump provided in the first pipe for moving water in the circulation flow path.

According to this configuration, the air in the circulation flow path can be sent to the water container by driving the circulation pump to circulate the water in the circulation flow path. This replaces the air in the circulation flow path with water, filling the circulation flow path with water. Here, the pressure sensor detects the pressure of the gas in the third tube that communicates with the circulation flow path. This makes it possible to reduce the possibility that the detection accuracy of the pressure sensor will be affected by the mixture of water and air. As a result, the detection accuracy of the pressure sensor can be maintained at a good level.

With this configuration, the circulation flow path is a flow path separate from the flow path in the second pipe. Therefore, compared to a configuration in which the circulation flow path is connected to the flow path in the second pipe, it is possible to reduce the influence of the flow of water in the second pipe on the circulation flow path.

A rice cooker according to one aspect of the present disclosure includes:
The water supply pump may further include a control unit that controls the operation of the water supply pump and the circulation pump.
The control unit may drive the circulation pump to circulate the water contained in the water container through the circulation flow path, and then drive the water supply pump to supply the water contained in the water container to the pot.

According to this configuration, the water in the water container is circulated in the circulation flow path before being sent to the pot. As described above, by circulating the water in the circulation flow path, the air in the circulation flow path is replaced with water, so the detection accuracy of the pressure sensor can be maintained at a good level. In other words, according to this configuration, the water in the water container can be sent to the pot with good detection accuracy of the pressure sensor. Therefore, the amount of water in the water container and the amount of water lost in the water container due to the water being sent to the pot can be detected with high accuracy.

A rice cooker according to one aspect of the present disclosure includes:
a fourth pipe branching from the first pipe;
The device may further include an air pump provided in the fourth tube, the drive of which is controlled by the control unit to send air from the outside to the first tube via the fourth tube.

With this configuration, when the air pump is driven, the air sent by the air pump pushes the water in the first tube back into the water container. This prevents water from leaking out of the first tube when the water container is removed from the rice cooker.

A rice cooker according to one aspect of the present disclosure includes:
The device may further include a temperature detection unit that detects water temperature or air temperature and outputs temperature information to the control unit.
The control unit may, when the temperature information is lower than a preset temperature, drive the circulation pump to circulate the water contained in the water container through the circulation flow path.

If the temperature of the water in the water container is low, there is a risk that the water will freeze. With this configuration, when there is a risk that the water will freeze, the control unit drives the circulation pump to circulate the water in the circulation flow path. This makes it possible to reduce the possibility of the water freezing as described above.

A rice cooker according to one aspect of the present disclosure includes:
The water supply device may further include an ultraviolet ray irradiation unit that is controlled by the control unit to irradiate ultraviolet rays toward the water contained in the water container,
The control unit may drive the circulation pump to circulate the water contained in the water container through the circulation flow path when driving the ultraviolet irradiating unit to irradiate ultraviolet light.

By irradiating the water in the water container with ultraviolet light, the proliferation of bacteria in the water in the water container can be suppressed. Here, when the water in the water container is stationary, the ultraviolet light irradiated by the ultraviolet light irradiating unit only hits the surface of the water in the water container. With this configuration, when the ultraviolet light irradiating unit irradiates ultraviolet light, the control unit drives the circulation pump to circulate the water contained in the water container in the circulation flow path. This causes the water in the water container to move, and the water located on the surface is replaced. Therefore, the ultraviolet light irradiated by the ultraviolet light irradiating unit can hit many parts of the water in the water container. As a result, the proliferation of bacteria in the water in the water container can be suppressed more effectively than with a configuration in which the water is not circulated.

A rice cooker according to one aspect of the present disclosure includes:
The water supply system may further include a water supply on-off valve provided in the second pipe for opening and closing a flow path within the second pipe.

With this configuration, water can be sent from the water container to the pot via the flow path in the second pipe by opening the water supply on-off valve.

With this configuration, by closing the water supply valve, it is possible to prevent the water in the second pipe on the pot side of the water supply valve from flowing back into the water container. This makes it possible to stabilize the amount of water stored in the water container.

In one aspect of the present disclosure, a rice cooker includes:
The water container may have an opening formed therein that connects the inside of the water container with the outside.

With this configuration, the inside of the water container is connected to the outside through the opening. Therefore, the water container can be maintained at atmospheric pressure regardless of the amount of water remaining in the water container. In other words, there is little pressure fluctuation due to changes in the amount of water remaining in the water container. This makes it possible to maintain good pressure detection accuracy by the pressure sensor.

A rice cooker according to one aspect of the present disclosure includes:
a storage unit in which shape information regarding the shape of the internal space of the water container is stored;
The water supply device may further include a water storage amount calculation unit that calculates the amount of water stored in the water container based on the pressure detected by the pressure sensor and the shape information stored in the memory unit.

While the water level in a water container can be detected with high accuracy using only the pressure detected by a pressure sensor, there are cases where the amount of water in the water container cannot be detected with high accuracy. For example, if the water container has a shape in which the cross-sectional area varies depending on the vertical position, it is more difficult to detect the amount of water in the water container than to detect the water level in the water container. With this configuration, by using shape information regarding the shape of the internal space of the water container, the amount of water stored in the water container is calculated according to the water level in the water container, which is determined based on the pressure detected by the pressure sensor. This makes it possible to calculate the amount of water stored in the water container with high accuracy.

First Embodiment
A first embodiment, which is one aspect of the present disclosure, will be described below. The first embodiment described below is merely one example of the present disclosure. Fig. 1 is a perspective view showing the appearance of a rice cooker according to the first embodiment. Fig. 2 is a perspective view showing the appearance of the rice cooker with the lid of the housing open.

As shown in Figures 1 and 2, the rice cooker 1 includes a pot 2, a housing 3 that houses the pot 2, an upper frame 4, a lower frame 5, a hinge section 6 arranged above the housing 3, a lid 7, a heating section 8 (see Figure 13), and a control section 20 (see Figure 13) that controls the operation of the entire rice cooker 1.

The pot 2 shown in FIG. 2 is cylindrical with a bottom. Rice is placed in the pot 2 during cooking.

As shown in FIG. 2, the upper frame 4 constitutes the upper part of the housing 3. When viewed from the top-bottom direction, an insertion opening (not shown) into which the pot 2 is inserted is formed in the center of the upper frame 4. The top-bottom direction is a direction perpendicular to the top surface of the upper frame 4, and is the height direction of the rice cooker 1. Viewing the rice cooker 1 from the top-bottom direction has the same meaning as viewing the rice cooker 1 from a plan view. The pot 2 can be inserted from above into the insertion opening. This allows the pot 2 to be accommodated in the housing 3 (see FIG. 2). The pot 2 accommodated in the housing 3 can be removed upwards from the insertion opening. This allows the pot 2 to be removed from the housing 3.

When the pot 2 is housed in the housing 3, a gap is formed between the outer peripheral surface of the pot 2 and the side surface 3B and bottom frame 5 of the housing 3. The heating unit 8 and the control unit 20 (see FIG. 13) are disposed in the gap. In the first embodiment, the heating unit 8 is disposed between the outer peripheral surface of the pot 2 and the side surface 3B and bottom frame 5 of the housing 3, and the control unit 20 is disposed between the outer peripheral surface of the pot 2 and the side surface 3B of the housing 3.

The upper frame 4 and the lower frame 5 protrude in the width direction relative to the other parts of the housing 3 than the upper frame 4 and the lower frame 5. The width direction is the left-right direction when the rice cooker 1 is viewed from the front. An opening is formed in the protruding part of the upper frame 4 into which the rice container 100 described below is inserted. The protruding part of the lower frame 5 supports the rice container 100 described below.

As shown in FIG. 2, the cover 7 is attached to the hinge portion 6. The cover 7 can rotate around the hinge portion 6. The cover 7 is supported by the housing 3 so that it can rotate.

The lid 7 can be rotated between the pot open position shown in FIG. 2 and the pot closed position shown in FIG. 1.

When the lid body 7 rotates, the pivot tip 7A of the lid body 7 moves toward and away from the upper frame 4 of the housing 3. In other words, the lid body 7 covers the opening 2A (see FIG. 2) of the pot 2 in an openable and closable manner. The hinge portion 6 is disposed at the rear of the rice cooker 1. Therefore, the pivot tip 7A of the lid body 7 is located at the front of the rice cooker 1. As a result, when the lid body 7 rotates to the pot open position, the front side of the rice cooker 1 opens (see FIG. 2). This allows the user to easily access the pot 2 and serve rice.

As shown in FIG. 2, when the lid 7 is in the pot-opening position, the pivot tip 7A of the lid 7 is separated from the upper frame 4 of the housing 3. At this time, the pot 2 is exposed upward.

As shown in FIG. 1, when the lid body 7 is in the pot closing position, the pivoting tip 7A of the lid body 7 is supported by the upper frame 4 of the housing 3. At this time, the lid body 7 covers the opening 2A (see FIG. 2) of the pot 2 from above. As shown in FIG. 2, the lid body 7 has an engaging portion 71, and the housing 3 has an engaged portion 42 on the upper frame 4. When the lid body 7 is in the pot closing position shown in FIG. 1, the engaging portion 71 and the engaged portion 42 engage with each other. This prevents the lid body 7 from unintentionally separating from the upper frame 4 of the housing 3.

The rice cooker 1 includes a heating unit 8 (see FIG. 13). The heating unit 8 is, for example, an induction heating (IH) type heating device. The induction heating (IH) type heating device includes a heating coil. The induction heating (IH) type heating device generates eddy currents in the metal pot 2 by a high-frequency magnetic field that is generated when a high-frequency current is passed through the heating coil. This heats the pot 2. Although not shown, the heating unit 8 is located below the pot 2 inside the housing 3. In the first embodiment, the heating unit 8 covers the bottom surface of the pot 2 and the lower part of the outer surface of the pot 2.

Figure 3 is a perspective view showing the appearance of the rice cooker with the lid of the rice container open. Figure 4 is a perspective view showing the internal structure of the rice cooker of Figure 1. Figure 5 is a perspective view showing the internal structure of the rice cooker of Figure 1. In the first embodiment, the rice cooker 1 is an automatic-adding type rice cooker that automatically moves rice and water to the pot 2 to cook rice. As shown in Figures 3 to 5, the rice cooker 1 includes, in the housing 3, a rice container 100 that contains rice therein, a water container 300 that contains water therein, a rice supply section 200 that supplies the rice contained in the rice container 100 to the pot 2, and a water supply section 400 that supplies the water contained in the water container 300 to the pot 2.

As shown in FIG. 1, the rice container 100 is supported by the lower frame 5 of the housing 3. As shown in FIG. 1 and FIG. 4, the rice container 100 includes a container body 110, an outer cover 120, and a lid body 130.

As shown in Figures 4 and 5, the container body 110 is box-shaped and open at the top. Rice is stored in the internal space 111 of the container body 110. The container body 110 is inserted into an opening formed in the protruding portion of the upper frame 4. As a result, the lower part of the container body 110 is located below the upper frame 4, and the upper part of the container body 110 is located above the upper frame 4.

The outer cover 120 shown in Figures 1 to 3 covers the front of the lower part of the container body 110 shown in Figures 4 and 5. The sides of the lower part of the container body 110 other than the front part are covered by the side 3B of the housing 3. This prevents the container body 110 from being exposed to the outside. The outer cover 120 and the side 3B of the housing 3 are located below the upper part of the container body 110 and do not cover the upper part of the container body 110.

As shown in Figs. 1 and 3, the lid body 130 is attached to the hinge portion 140. The hinge portion 140 is disposed at the rear of the rice cooker 1. The hinge portion 140 is supported by the upper frame 4. The lid body 130 can rotate around the hinge portion 140.

The lid 130 can be rotated between the closed position shown in FIG. 1 and the open position shown in FIG. 3.

As shown in FIG. 3, the lid 130 is box-shaped and open on the bottom. The internal space of the lid 130 is larger than the top of the container body 110 and can accommodate the top of the container body 110.

As shown in FIG. 1, when the lid body 130 is in the closed position, the lid body 130 closes the internal space 111 of the container body 110 from above. At this time, the lower end portion 130A of the lid body 130 in the closed position is in contact with the upper surface of the upper frame 4 from above. As a result, the lid body 130 in the closed position is supported by the upper frame 4.

As shown in FIG. 3, when the lid body 130 is in the open position, the lower end portion 130A of the lid body 130 is separated from the upper frame 4, except for the rear portion connected to the hinge portion 140. At this time, the lid body 130 exposes the internal space 111 of the container body 110 to the outside, and rice can be stored in the internal space 111 of the container body 110.

As shown in FIG. 4, the rice sending section 200 includes a rice measuring section 210 and a rice sending path 220. The rice measuring section 210 measures the amount of rice supplied from the rice container 100 and supplies the specified amount of rice to the rice sending path 220. The rice sending path 220 is a path for transporting the rice supplied from the rice measuring section 210 to the pot 2.

The rice measuring unit 210 includes a housing with a built-in measuring blade and a motor (not shown). The inside of the housing is connected to the internal space 111 of the container body 110 of the rice container 100. The measuring blade rotates as the motor rotates. As a result, the rice inside the housing is sent to the rice sending path 220 by the rotating measuring blade. In the first embodiment, the amount of rice sent to the rice sending path 220 is controlled by the rotation speed of the motor.

The rice sending path 220 is piped from below the rice measuring section 210, facing upward at the rear of the rice cooker 1, to above the upper frame 4 of the housing 3, and above the upper frame 4 in a substantially horizontal direction to above the pot 2. One end of the rice sending path 220 is connected to the housing of the rice measuring section 210. The other end of the rice sending path 220 is located above the opening 2A of the pot 2, and the opening 2A opens toward it. The rice inside the housing of the rice measuring section 210 is transferred to the inside of the pot 2 through the rice sending path 220 by a pump (not shown).

As shown in Figs. 1 and 5, the water container 300 is located at the bottom of the housing 3. The water container 300 is arranged alongside the bottom of the rice container 100. As shown in Figs. 1 and 4, the water container 300 is supported by the bottom frame 5 of the housing 3. As shown in Figs. 4 and 5, the water container 300 is provided inside the housing 3. As shown in Fig. 5, the water container 300 is located below the pot 2. The water container 300 can be attached to and removed from the housing 3.

Figure 6 is a perspective view showing the water container and water supply unit without the cover plate. Figure 7 is a plan view showing the water container and water supply unit without the cover plate. Figure 8 is a perspective view showing the water container and water supply unit including the cover plate. Figure 9 is a plan view showing the water container and water supply unit including the cover plate.

As shown in Figures 6 to 9, the water container 300 comprises a bottom plate 301, a side plate 302, a cover plate 303, and a slide plate 304. The side plate 302 stands upright from the outer edge of the bottom plate 301. As shown in Figures 6 and 7, the water container 300 is configured by the bottom plate 301 and the side plate 302 in a box shape with an open top. As shown in Figure 8, the cover plate 303 is supported by the upper end of the side plate 302. The bottom plate 301, the side plate 302, and the cover plate 303 form an internal space 300A (see Figures 6 and 7) of the water container 300. Water is stored in the internal space 300A of the water container 300.

As shown in Figures 8 and 9, a recess 303A is formed in the cover plate 303. An opening 303B is formed in the bottom surface 303Aa of the recess 303A.

The slide plate 304 is disposed in the recess 303A. The slide plate 304 is supported by the cover plate 303 so that it can slide in the front-rear direction along the recess 303A. The front-rear direction is perpendicular to the up-down direction and the width direction. The slide plate 304 slides between a closed position where it closes the opening 303B of the cover plate 303 and an open position (see Figures 8 and 9) which is a position forward of the closed position and out of the opening 303B. When the slide plate 304 is in the open position shown in Figures 8 and 9, the internal space 300A of the water container 300 is exposed to the outside through the opening 303B. When the slide plate 304 is in the closed position, the slide plate 304 is located directly above the opening 303B and covers the opening 303B. As a result, the internal space 300A of the water container 300 is closed by the slide plate 304.

A gap is formed between the slide plate 304 and the cover plate 303. The gap is formed both between the bottom surface 303Aa of the recess 303A and the slide plate 304, and between the side surface 303Ab of the recess 303A and the slide plate 304. When the slide plate 304 is in the closed position, the internal space 300A of the water container 300 is connected to the outside through the opening 303B and the gap. When the slide plate 304 is in the open position, the internal space 300A of the water container 300 is connected to the outside through the opening 303B. The gap and the opening 303B are an example of an opening. Note that the opening is not limited to the gap and the opening 303B. For example, as an example of the opening, a through hole that connects the internal space 300A of the water container 300 to the outside may be formed in the cover plate 303 in addition to the opening 303B.

As shown in Figures 6 to 9, a cover plate 300B is attached to the front side plate 302 of the water container 300. As shown in Figure 1, when the water container 300 is attached to the housing 3, the cover plate 300B forms part of the housing 3. The cover plate 300B is grasped by the user placing their fingers or the like on the underside 300Ba of the cover plate 300B (see Figures 2 and 8). The water container 300 is removed from the housing 3 by being pulled forward in this state. The slide plate 304 of the water container 300 removed from the housing 3 is slid to the open position by the user, and water is refilled into the internal space 300A of the water container 300 from the opening 303B. The water container 300 is then attached to the housing 3.

In the first embodiment, if the sliding plate 304 of the water container 300 is in the closed position when it is attached to the housing 3, the sliding plate 304 slides from the closed position to the open position by being pressed against a wall surface or the like provided inside the rice cooker 1. This allows ultraviolet light to be irradiated from the light source 320 (described later) through the opening 303B into the internal space 300A when the water container 300 is attached to the housing 3.

As shown in Figures 6 and 7, the water container 300 is provided with a step portion 305. The step portion 305 is attached to the upper surface of the bottom plate 301 and the front surface of the rear side plate 302. The step portion 305 may be integrally molded with the water container 300.

The step portion 305 has a two-step staircase shape and has two upper surfaces 305A and 305B. The upper surface 305A is higher than the upper surface 305B. The upper surface 305A is located at the same height as the water surface when the amount of water set as the maximum amount of water to be contained in the water container 300 is contained in the water container 300. In the first embodiment, the upper surface 305A is located slightly below the upper end of the side plate 302. The upper surface 305B is located at the same height as the water surface when the amount of water set as the minimum amount of water to be contained in the water container 300 is contained in the water container 300. In the first embodiment, the upper surface 305B is located slightly above the upper ends of the communication ports 306 and 307 described later. The heights of the upper surfaces 305A and 305B are not limited to the above heights. In addition, a water level line or the like may be provided on the side plate 302 as a guide.

Two communication ports 306, 307 are formed in the rear side plate 302 of the water container 300. The communication ports 306, 307 communicate the internal space 300A of the water container 300 with the outside of the water container 300. When the water container 300 is attached to the housing 3, the communication port 306 is connected to one end 411A (see FIG. 11) of a first tube 411 of the water supply unit 400 described later, and the communication port 307 is connected to one end 412A (see FIG. 11) of a second tube 412 of the water supply unit 400 described later. The communication port 306 is an example of a first communication port. The communication port 307 is an example of a second communication port.

The water container 300 is provided with two on-off valves 308. One of the two on-off valves 308 opens and closes the communication port 306. The other of the two on-off valves 308 opens and closes the communication port 307. Since the two on-off valves 308 have the same configuration, the configuration of the on-off valve 308 that opens and closes the communication port 306 will be described, and the configuration of the on-off valve 308 that opens and closes the communication port 307 will be omitted.

Figure 10 is a cross-sectional view showing the A-A cross section of Figure 7. As shown in Figure 10, the on-off valve 308 includes housings 308A and 308B, a ring-shaped packing 308C, a valve body 308D, and a coil spring 308E.

The housing 308A is integrally molded with the water container 300. A communication port 306 is formed in the housing 308A. The internal space of the housing 308A is connected to the outside of the water container 300 via the communication port 306. The housing 308B is attached to the housing 308A via a gasket 308C. The internal space of the housing 308B is connected to the internal space of the housing 308A. In addition, a through hole (not shown) that opens downward is formed in the housing 308B, and the internal space of the housing 308B is connected to the internal space 300A of the water container 300 via the through hole. In other words, the internal space 300A of the water container 300 is connected to the outside of the water container 300 via the internal space of the housing 308B and the internal space of the housing 308A.

A filter 308F is disposed at the entrance of the internal space of the housing 308B (the portion communicating with the internal space 300A of the water container 300). The water in the internal space 300A of the water container 300 flows into the internal space of the housing 308B via the filter 308F. The filter 308F can prevent foreign matter mixed in the water in the internal space 300A of the water container 300 from entering the internal space of the housing 308B. In the first embodiment, the filter 308F is mesh-shaped, but it is not limited to a mesh-shaped filter, and may be configured in any way that can prevent the entry of the foreign matter described above.

Valve body 308D is arranged from inside housing 308A to inside housing 308B. Coil spring 308E is arranged in housing 308A. Coil spring 308E biases valve body 308D backward. As a result, when water container 300 is not attached to housing 3, surface 308Da of valve body 308D contacts surface 308Aa of housing 308A. As a result, communication between the inside and outside of water container 300 through communication port 306 is blocked. In other words, communication port 306 is blocked. On the other hand, when water container 300 is attached to housing 3, valve body 308D is pushed by one end 411A of first tube 411 of water supply section 400, and moves forward against the biasing force of coil spring 308E. As a result, as shown in FIG. 10, surface 308Da of valve body 308D moves away from surface 308Aa of housing 308A, and the inside and outside of water container 300 communicate with each other via communication port 306. In other words, communication port 306 is opened.

As shown in Figures 6, 7, and 10, a recess 301A is formed on the upper surface of the bottom plate 301 of the water container 300. Two opening and closing valves 308 are disposed in the recess 301A. The portion of the upper surface of the bottom plate 301 of the water container 300 other than the recess 301A may be a horizontal surface or an inclined surface inclined toward the recess 301A. By having the inclined surface in this portion, the water in this portion flows along the inclined surface to the recess 301A.

As shown in Figs. 8 and 9, the rice cooker 1 includes an attachment/detachment detection unit 310 for detecting whether the water container 300 is attached to the housing 3. In the first embodiment, the attachment/detachment detection unit 310 is disposed inside the housing 3, and includes a photointerrupter 311 and a rotating member 312.

The photointerrupter 311 is supported by a frame (not shown) disposed inside the housing 3. The photointerrupter 311 has a light emitting section (not shown) and a light receiving section (not shown) that face each other. The configuration of the photointerrupter 311 is publicly known, so a detailed description will be omitted here.

The rotating member 312 is supported by a frame (not shown) arranged inside the housing 3 so as to be rotatable around a rotating shaft 312A extending in the vertical direction. The rotating member 312 can rotate between a shielding position and a retracted position. When the rotating member 312 is in the shielding position, a part of the rotating member 312 is positioned between the light emitting portion and the light receiving portion of the photointerrupter 311. This blocks the optical path from the light emitting portion to the light receiving portion. When the rotating member 312 is in the retracted position, the part of the rotating member 312 retracts from between the light emitting portion and the light receiving portion of the photointerrupter 311. This opens the optical path from the light emitting portion to the light receiving portion. The rotating member 312 is biased to the shielding position by a spring (not shown).

When the water container 300 is not attached to the housing 3 (in other words, when the water container 300 is removed from the housing 3), the rotating member 312 is biased by a spring and is in the shielding position. At this time, a first signal (e.g., one of a high-level and low-level signal) is output from the photointerrupter 311 to the control unit 20.

When the water container 300 is attached to the housing 3, the side plate 302 of the water container 300 presses the rotating member 312. This causes the rotating member 312 to rotate from the shielding position to the retracted position along the circumferential direction R shown by the arrow in FIG. 9. At this time, a second signal (e.g., the other of the high-level and low-level signals) is output from the photointerrupter 311 to the control unit 20. Note that FIGS. 8 and 9 show the rotating member 312 in the retracted position.

When the water container 300 is removed from the housing 3, the rotating member 312 is biased by the spring and rotates in the circumferential direction R from the retracted position to the shielded position.

The control unit 20 detects whether the water container 300 is attached to the housing 3 based on the signal from the photointerrupter.

As shown in Figs. 8 and 9, the rice cooker 1 includes a light source 320 that emits ultraviolet light. The light source 320 is an example of an ultraviolet light emitting unit. The light source 320 is supported by a frame (not shown) disposed inside the housing 3.

The light source 320 is disposed directly above the opening 303B. The light emission port of the light source 320 faces downward. As a result, the light source 320 emits ultraviolet light through the opening 303B toward the internal space 300A of the water container 300. In other words, the light source 320 emits ultraviolet light toward the water contained in the water container 300. The light source 320 is controlled to be turned on and off by the control unit 20. In other words, the operation of the light source 320 is controlled by the control unit 20.

As shown in FIG. 5, the water supply unit 400 is disposed behind the water container 300 inside the housing 3.

Figure 11 is a perspective view showing the water supply unit. Figure 12 is a schematic diagram showing the water container, the water supply unit, and the pot.

As shown in Figures 11 and 12, the water supply unit 400 includes a first tube 411, a second tube 412, a third tube 413, a fourth tube 414, a water supply pump 421, an air pump 422, a pressure sensor 430, an on-off valve 441, and an on-off valve 442.

In the first embodiment, the first tube 411, the second tube 412, and the third tube 413 are made of a resin that does not bend easily, such as plastic, and a silicone tube, and the fourth tube 414 is made of a silicone tube. In addition, a part of the first tube 411 and the second tube 412 (the part where the on-off valves 441 and 442 described later are provided and the part connecting the housing 3 to the lid 7) is made of a material that bends easily (silicone in the first embodiment) like the fourth tube 414.

The materials of the first tube 411, the second tube 412, the third tube 413, and the fourth tube 414 are not limited to those described above. For example, the first tube 411, the second tube 412, the third tube 413, and the fourth tube 414 may be made of materials other than resin and silicon, such as metal and rubber, by covering a part of the tube with a spring to prevent deformation or buckling of the silicon tube. In addition, the first tube 411, the second tube 412, the third tube 413, and the fourth tube 414 may all be made of the same material, or may be made of different materials. In addition, the first tube 411, the second tube 412, the third tube 413, and the fourth tube 414 may be made of a plurality of types of materials. For example, in the first tube 411, the second tube 412, the third tube 413, and the fourth tube 414, the straight parts may be made of a material that does not bend easily, and the curved parts may be made of a material that bends easily. In this case, the two straight parts are connected by a tube made of an easily flexible material. The first tube 411, the second tube 412, the third tube 413, and the fourth tube 414 may be made of a single material. For example, the third tube 413 may be made only of a resin that does not easily bend, such as plastic.

In the first embodiment, one end and the other end of each of the first tube 411, the second tube 412, the third tube 413, and the fourth tube 414 are open.

As shown in Figures 10 and 12, one end 411A (see Figure 11) of the first tube 411 is connected to the communication port 306 of the water container 300. This allows the first tube 411 to communicate with the internal space 300A of the water container 300. As shown in Figures 11 and 12, the other end of the first tube 411 is connected to the second tube 412 at the branch position 412C. This allows the first tube 411 to communicate with the second tube 412.

As shown in FIG. 12, one end 412A (see FIG. 11) of the second pipe 412 is connected to the communication port 307 of the water container 300. As a result, the second pipe 412 is in communication with the internal space 300A of the water container 300. As shown in FIG. 5 and FIG. 12, the other end 412B of the second pipe 412 is located above the opening 2A of the pot 2. The other end 412B of the second pipe 412 opens toward the opening 2A, that is, toward the inside of the pot 2. As a result, the second pipe 412 communicates the internal space 300A of the water container 300 with the inside of the pot 2. An opening is formed at the branch position 412C of the second pipe 412 between the water pump 421 and the other end 412B (pot 2). The other end of the first pipe 411 is connected to this opening. As a result, the second pipe 412 is in communication with the first pipe 411.

As shown in FIG. 12, a portion of the second pipe 412 and the first pipe 411 form a circulation flow path 450. The portion of the second pipe 412 is the portion between the branch position 412C and one end 412A (communication port 307) in the second pipe 412. Water circulating from the communication port 307 of the water container 300 passes through the circulation flow path 450, reaches the communication port 306 of the water container 300, and returns to the water container 300. In this way, the water flow path circulates through the circulation flow path 450 and the water container 300.

10 and 12, the third tube 413 branches upward from the first tube 411. The third tube 413 may extend directly upward from the first tube 411, or may extend diagonally upward from the first tube 411. An opening is formed at a connection position 411B between one end 411A of the first tube 411 and the branching position 412C. The lower end of the third tube 413 is connected to this opening. As a result, the lower end of the third tube 413 is connected to the first tube 411. A pressure sensor 430 is attached to the upper end of the third tube 413. As a result, the upper end of the third tube 413 is closed. When at least a part of the first tube 411 is filled with water, a sealed air pocket is formed in the internal space 413A of the third tube 413.

As shown in Figures 11 and 12, the fourth tube 414 branches off from the second tube 412. One end of the fourth tube 414 is connected to the second tube 412. The other end of the fourth tube 414 is open to the atmosphere. An air pump 422 is disposed in the fourth tube 414.

In the first embodiment, as shown in FIG. 11, one end of the fourth tube 414 is connected to the second tube 412 between the branch position 412C of the second tube 412 and the water pump 421. However, the position of communication between the one end of the fourth tube 414 and the second tube 412 is not limited to this. For example, as shown in the schematic diagram of FIG. 12, one end of the fourth tube 414 may be connected to the second tube 412 at the branch position 412C. Also, for example, one end of the fourth tube 414 may be connected to the second tube 412 between the branch position 412C of the second tube 412 and the on-off valve 442. Also, for example, one end of the fourth tube 414 may be connected to the second tube 412 between the branch position 412C of the first tube 411 and the on-off valve 441.

The water pump 421 is a machine for sending water, and is, for example, a gear pump, tubing pump, or other pump that can control the direction of water supply. As shown in Figures 11 and 12, the water pump 421 is provided in the second pipe 412. In the first embodiment, the water pump 421 is provided between one end 412A and the branch position 412C in the second pipe 412. The position at which the water pump 421 is provided is not limited to the above position, and may be provided, for example, between the branch position 412C in the second pipe 412 and the on-off valve 442.

When the water supply pump 421 is driven, the water contained in the water container 300 is supplied to the inside of the pot 2 via the second pipe 412. In other words, the water supply pump 421 moves the water in the second pipe 412. When a gear pump is used as the water supply pump 421, in addition to supplying water from the water container 300 to the pot 2, it is possible to reverse the flow of water remaining in the second pipe 412 and send it to the water container 300.

The air pump 422 is a machine for sending air, such as a compressor. The air pump 422 is provided in the fourth tube 414. When the air pump 422 is driven, air is taken in from the other end of the fourth tube 414. The air taken in the fourth tube 414 is sent by the air pump 422 to the second tube 412 via the fourth tube 414. The air sent to the second tube 412 is sent through the second tube 412 to the water container 300 from the communication port 307. The air sent to the second tube 412 can also be sent to the first tube 411 via the branch position 412C, and sent to the water container 300 from the communication port 306 through the first tube 411.

When the fourth tube 414 is connected to the second tube 412 at the first tube 411, the taken-in air is sent to the first tube 411 via the fourth tube 414 by the air pump 422. The air sent to the first tube 411 can be sent to the second tube 412 via the branch position 412C.

As shown in FIG. 10, the pressure sensor 430 includes a sensor body 430A including a substrate, a packing 430B, a base portion 430C having an internal space, a cover 430D, and an O-ring 430E. The base portion 430C is attached to the upper end of the third tube 413 via an O-ring 430E. The sensor body 430A and the packing 430B are disposed inside the base portion 430C. The packing 430B is interposed between the sensor body 430A and the third tube 413. The cover 430D covers the base portion 430C from above. The packing 430B and the O-ring 430E maintain the airtightness of the third tube 413.

The sensor body 430A detects the pressure of the air in the internal space 413A of the third tube 413. The pressure of the air in the internal space 413A of the third tube 413 increases or decreases depending on the water level in the water container 300. For example, when the amount of water set as the maximum amount of water that can be contained in the water container 300 is contained in the water container 300, in other words, when the water surface in the water container 300 is at the same height as the upper surface 305A of the step portion 305, the sensor body 430A outputs a voltage (maximum voltage of 5V in the first embodiment) according to the detected pressure inside the third tube 413 to the control unit 20. As the water surface drops, the air pressure detected by the sensor body 430A decreases. At this time, the sensor body 430A outputs a voltage lower than 5V to the control unit 20. The control unit 20 detects the height of the water surface in the water container 300 according to the voltage output from the sensor body 430A.

The pressure sensor 430 is not limited to the above-mentioned configuration, and may be, for example, a capacitance sensor, an ultrasonic sensor, a radio wave sensor, etc. Furthermore, the control unit 20 may detect the height of the water surface in the water container 300 according to, for example, a current output from the sensor body 430A to the control unit 20, other than the voltage output from the sensor body 430A.

As shown in Figures 11 and 12, the on-off valve 441 is provided in the first tube 411 between the connection position 411B with the third tube 413 and the branch position 412C. The on-off valve 441 is opened and closed under the control of the control unit 20. The opening and closing of the on-off valve 441 opens and closes the flow path in the first tube 411. When the on-off valve 441 is opened and the flow path in the first tube 411 is opened, water can flow through the first tube 411. When the on-off valve 441 is closed and the flow path in the first tube 411 is closed, the flow of water through the first tube 411 is prevented by the on-off valve 441. The on-off valve 441 is an example of a circulation on-off valve.

The position of the on-off valve 441 is not limited to between the connection position 411B of the first pipe 411 with the third pipe 413 and the branch position 412C, but may be between one end 411A of the first pipe 411 and the connection position 411B.

The on-off valve 442 is provided between the branch position 412C and the other end 412B in the second pipe 412. The on-off valve 442 is opened and closed under the control of the control unit 20. The opening and closing of the on-off valve 442 opens and closes the flow path in the second pipe 412. When the on-off valve 442 is opened and the flow path in the second pipe 412 is opened, water can flow through the second pipe 412. When the on-off valve 442 is closed and the flow path in the second pipe 412 is closed, the flow of water through the second pipe 412 is prevented by the on-off valve 442. The on-off valve 442 is an example of a water supply on-off valve.

In the first embodiment, each of the on-off valves 441, 442 includes a stepping motor, a conversion part that converts the rotational motion of the stepping motor into reciprocating motion by rotating, a valve body that deforms a part of the silicon tube that constitutes part of the first tube 411 and the second tube 412 by the operation of the conversion part, and a valve seat that faces the valve body. The tips of the valve body and the valve seat are wedge-shaped, and the silicon tube sandwiched between the valve body and the valve seat is crushed by the operation of the conversion part, and the internal space of the silicon tube is blocked. Note that the configuration of the on-off valves 441, 442 is not limited to the above configuration, and various known configurations can be adopted.

Figure 13 is a block diagram illustrating the hardware configuration of a rice cooker. The control unit 20 shown in Figure 13 controls the overall operation of the rice cooker 1. Processes such as the rice cooking process described below are executed under the control of the control unit 20.

The memory unit 25 shown in FIG. 13 is a recording medium that records various information including programs and data necessary to realize the functions of the rice cooker 1. The memory unit 25 is realized, for example, by a semiconductor memory device such as a flash memory, an SSD (Solid State Drive), a magnetic storage device such as a hard disk, or other storage device alone or in appropriate combination thereof. The memory unit 25 may also include volatile memory such as a high-speed SRAM or DRAM that temporarily stores various information.

The memory unit 25 stores shape information of the water container 300. The shape information is information related to the shape of the water container 300. In the first embodiment, the shape information is a data table consisting of each height position of the internal space 300A of the water container 300 and the volume of water corresponding to each height position. The volume of water corresponding to each height position is the volume of water contained in the internal space 300A when the water surface is located at each height position.

In the first embodiment, a step surface 300C is formed at the front of the water container 300, as shown in FIG. 10. As a result, in the internal space 300A of the water container 300, the cross-sectional area (cross-sectional area along the horizontal plane) above the step surface 300C is larger than the cross-sectional area below the step surface 300C. In other words, in the first embodiment, the volume included in the shape information reflects the difference in the size of the cross-sectional areas described above. Specifically, when the height position is above the step surface 300C, the volume corresponding to the height position is the sum of the volume of the part below the step surface and the volume of the part above the step surface. On the other hand, when the height position is above the step surface 300C, the volume of water corresponding to the height position is the volume of the part below the step surface.

The shape information is not limited to the data table described above. For example, the shape information may be a formula that uses the water level contained in the internal space 300A of the water container 300 as a variable and can calculate the volume of water contained in the internal space 300A of the water container 300 by substituting the variable.

The control unit 20 shown in FIG. 13 can be realized in various ways. For example, a processor that cooperates with software to realize a predetermined function may be used as the control unit 20. If a processor is used as the control unit 20, the control unit 20 can execute various processes by reading a program from the storage unit 25 that stores the program and executing it. Since the processing content can be changed by changing the program stored in the storage unit 25, the degree of freedom in changing the control content can be increased. The processor includes, for example, a CPU (Central Processing Unit) and an MPU (Micro-Processing Unit). Furthermore, wired logic in which the program cannot be rewritten may be used as the control unit 20. Using wired logic as the control unit 20 is effective in improving the processing speed. Examples of wired logic include ASIC (Application Specific Integrated Circuit). Furthermore, the control unit 20 may be realized by combining a processor and wired logic. If the control unit 20 is realized by combining a processor and wired logic, the degree of freedom in software design can be increased while improving the processing speed. Furthermore, the control unit 20 and a circuit having a function different from that of the control unit 20 may be configured with a single semiconductor element. An example of a circuit having a different function is an A/D and D/A conversion circuit. Furthermore, the control unit 20 may be configured with a single semiconductor element, or may be configured with multiple semiconductor elements. When configured with multiple semiconductor elements, each control described in the claims may be realized with different semiconductor elements. Furthermore, the control unit 20 may be configured with a configuration including a semiconductor element and a passive component such as a resistor or a capacitor.

The communication interface 28 shown in FIG. 13 may be any interface that enables communication between the rice cooker 1 and an external device. The communication interface 28 can be realized in various forms. For example, the communication interface 28 may be connected to an external device by wire, or may be connected to an external device by wireless communication. The communication interface 28 that connects the device of the present disclosure to an external device by wire is effective in terms of communication security and stability. Examples of the communication interface 28 for wired connection include a wired LAN based on the Ethernet (registered trademark) standard, or a wired connection using an optical fiber cable. Examples of the communication interface 28 for wireless connection include a wireless connection to an external device via a base station or the like, or a direct wireless connection to an external device. Examples of wireless connections with external devices via base stations include IEEE802.11-compatible wireless LANs that wirelessly communicate with a WiFi (registered trademark) router, third-generation mobile communication systems (commonly known as 3G), fourth-generation mobile communication systems (commonly known as 4G), fifth-generation mobile communication systems (commonly known as 5G), IEEE802.16-compatible WiMax (registered trademark), or LPWA (Low Power Wide Area). Using a communication interface 28 that directly wirelessly connects the device of the present disclosure to an external device is effective in improving the security of communication. In addition, using a communication interface 28 that directly wirelessly connects the device of the present disclosure to an external device allows the device of the present disclosure to communicate with an external device even in places where there is no relay device such as a WiFi (registered trademark) router. Examples of the communication interface 28 that directly and wirelessly connects the device of the present disclosure to an external device include communication using Bluetooth (registered trademark), communication using Near Field Communication (NFC) via a loop antenna, and infrared communication.

The signal output unit 26 shown in FIG. 13 outputs a signal to the control unit 20. As shown in FIG. 13, the signal output unit 26 includes a pressure sensor 430, an attachment/detachment detection unit 310, a temperature detection unit 54, and a user interface (UI) 55.

As described above, the pressure sensor 430 detects the air pressure in the internal space 413A of the third tube 413 and outputs a voltage corresponding to that pressure to the control unit 20.

As described above, the attachment/detachment detection unit 310 detects whether the water container 300 is attached to the housing 3. The attachment/detachment detection unit 310 outputs a first signal to the control unit 20 when the water container 300 is not attached to the housing 3, and outputs a second signal to the control unit 20 when the water container 300 is attached to the housing 3.

The temperature detection unit 54 is disposed at any position on the rice cooker 1. The temperature detection unit 54 detects the temperature of the rice cooker 1 and its surroundings. The temperature detection unit 54 outputs temperature information, which is information related to the detected temperature, to the control unit 20. The temperature information is not limited to the temperature of the rice cooker 1 and its surroundings. For example, the temperature detection unit 54 may be disposed inside the water container 300 and detect the temperature of the water contained in the water container 300. In this case, the temperature information is information related to the detected water temperature. In other words, the temperature information is information related to the detected temperature. Also, for example, the temperature detection unit 54 may be disposed at a position close to the pot 2 below the pot 2. In this case, the temperature detection unit 54 can detect the temperature inside the pot 2 by detecting the temperature of the bottom of the pot 2. In other words, a temperature sensor for detecting the temperature inside the pot 2 may be used as the temperature detection unit 54 for detecting the temperature of the rice cooker 1 and its surroundings.

The user interface 55 is composed of, for example, buttons that accept input from the user, a touch panel, and the like. The user interface 55 is provided, for example, on the upper surface 7B (see FIG. 1) of the lid body 7. The user operates the user interface 55, for example, to set the amount of rice to be cooked, the cooking method, the time when the rice is ready, and the like.

The user interface 55 is used by the user to input information to the rice cooker 1. Various embodiments of the user interface 55 are possible. For example, the user interface 55 may be configured with mechanical operating members. The user interface 55 may also be configured with a transparent plate-like operating member installed above the display. Such a transparent plate-like operating member may be of the contact type or of the non-contact type. The user interface 55 may also be formed by capturing images of the user's actions using a camera and having the rice cooker 1 recognize the actions. The user interface 55 may also be formed by having the rice cooker 1 receive sounds made by the user. An example of such a configuration is a smart speaker.

Various embodiments are possible regarding where the user interface 55 is provided. The user interface 55 may be provided in the rice cooker 1 as described above, or may be provided separately from the rice cooker 1. When the user interface 55 is provided separately from the rice cooker 1, communication between the user interface 55 and the rice cooker 1 is made possible by wired or wireless communication. In this case, the user interface 55 and the rice cooker 1 may be able to communicate directly, or may be able to communicate indirectly via the Internet or an access point. In addition, when communicating wirelessly, communication may be possible using a mobile communication method, or communication may be possible in accordance with other standards. Furthermore, when communicating wirelessly, remote wireless or close-proximity wireless may be used.

A signal is input from the control unit 20 to the signal input unit 27 shown in FIG. 13. The control unit 20 controls the operation of the signal input unit 27 by outputting a signal to the signal input unit 27. As shown in FIG. 13, the signal input unit 27 includes the heating unit 8 described above, the light source 320, the water pump 421, the air pump 422, the on-off valve 441, and the on-off valve 442. The signal input unit 27 further includes a display unit 61 and a speaker 62.

The display unit 61 is configured with a display of the rice cooker 1, etc. The display unit 61 is provided, for example, on the upper surface 7B of the lid body 7 (see FIG. 1). The speaker 62 outputs audio. The speaker 62 is provided, for example, on the outer surface of the housing 3. For example, if the aforementioned user interface 55 is configured with a touch panel, the display unit 61 may be the screen of the touch panel.

The rice cooking process of the rice cooker 1, which is executed under the control of the control unit 20, is described below. When the control unit 20 acquires information on cooking instructions from outside the control unit 20, it starts the rice cooking process. The information on cooking instructions is sent to the control unit 20 in response to the input of cooking instructions by the user through the user interface 55. For example, the information on cooking instructions is sent from the input unit to the control unit 20 in response to the input of cooking instructions by the user through an input unit such as a switch or touch panel provided on the housing 3 and lid 7 of the rice cooker 1. Also, for example, the information on cooking instructions may be a cooking instruction input by the user in an external device such as a smartphone or personal computer, and sent from the external device to the control unit 20 of the rice cooker 1. In this case, the rice cooker 1 and the external device are configured to be able to communicate with each other via wire or wirelessly.

Figure 14 is a flow chart showing an example of the rice cooking process. As shown in Figure 14, the rice cooking process starts when the rice cooking instruction as described above is received (S10). The rice cooking process includes a rice sending process S20, a water sending process S30, a pre-cooking process S40, a heating process S50, a boiling process S60, and a steaming process S70.

In the rice sending step S20, the control unit 20 determines the amount of rice required for cooking in accordance with the cooking instruction. The control unit 20 controls the rice sending unit 200 to send the determined amount of rice from the rice container 100 into the pot 2.

In the water supply step S30, the control unit 20 determines the amount of water required for cooking rice in accordance with the cooking instruction. The control unit 20 controls the water supply unit 400 to send the determined amount of water from the water container 300 into the pot 2. The water supply step S30 will be described in detail later.

The rice sending process S20 and the water sending process S30 may be performed in parallel. The water sending process S30 may be performed prior to the rice sending process S20.

In the pre-cooking process S40, the control unit 20 controls the heating unit 8 to heat the pot 2. At this time, the control unit 20 keeps the temperature inside the pot 2 below the gelatinization temperature (e.g., 55°C) to allow the rice to absorb water. The control unit 20 recognizes the temperature inside the pot 2 based on information input from a temperature sensor (not shown).

The temperature sensor is disposed adjacent to the pot 2 below the pot 2. The temperature sensor is disposed below the center of the pot 2 in a plan view. The temperature sensor detects the temperature inside the pot 2 by detecting the temperature at the bottom of the pot 2. The temperature sensor outputs information related to the detected temperature.

In the heating step S50, the control unit 20 controls the heating unit 8 to heat the pot 2 more strongly than in the pre-cooking step S40, raising the temperature inside the pot 2 and bringing the pot 2 to a boiling state.

In the boiling step S60, the control unit 20 controls the heating unit 8 to heat the pot 2 less strongly than in the temperature increasing step S50. However, the heating intensity of the heating unit 8 is maintained at a level that maintains the boiling of the water in the pot 2.

When the water in pot 2 is absorbed by the rice and boils away, the temperature in pot 2 rises due to heating and becomes higher than the boiling point of water (100°C). When the temperature in pot 2 reaches a temperature higher than the boiling point of water (e.g., 120°C), the control unit 20 controls the heating unit 8 to stop heating pot 2. This period during which heating of pot 2 is stopped is the steaming process S70.

Figure 15 is a flow chart showing an example of the water supply process. Below, the water supply process S30 will be described with reference to Figure 15. At the start of the water supply process S30, the on-off valves 441 and 442 are closed, and the water supply pump 421 and the air pump 422 are stopped.

As shown in FIG. 15, in the water supply process S30, the control unit 20 first detects whether the water container 300 is attached to the housing 3 based on a signal obtained from the attachment/detachment detection unit 310 (S110).

When the control unit 20 receives the first signal from the attachment/detachment detection unit 310, it determines that the water container 300 is not attached to the housing 3 (S110: NO). In this case, the control unit 20 notifies the user of an abnormality that the water container 300 is not attached to the housing 3 (S120), and executes the first drainage operation S270 and the second drainage operation S280 described below to end the rice cooking process. The notification is performed, for example, by displaying a message on the display unit 61 controlled by the control unit 20, and by outputting audio from the speaker 62 controlled by the control unit 20. The notification may be sent to an external device such as a smartphone or a personal computer. The first drainage operation S270 and the second drainage operation S280 may be performed before the abnormality notification (S120) or in parallel with the abnormality notification (S120).

On the other hand, when the control unit 20 receives the second signal from the attachment/detachment detection unit 310, the control unit 20 determines that the water container 300 is attached to the housing 3 (S110: YES).
A circulation operation S130 is executed.

In the circulation operation S130, the control unit 20 opens the on-off valve 441. This causes the on-off valve 441 to open and the on-off valve 442 to close. Next, the control unit 20 drives the water supply pump 421. This causes the water in the water container 300 to circulate through the circulation flow path 450 by the water supply pump 421, if there is water in the water container 300. As a result, the circulation flow path 450 is filled with water. The air present in the circulation flow path 450 is pushed by the circulating water to reach the water container 300, and flows out of the water container 300 through the gap between the slide plate 304 and the cover plate 303 and the opening 303B. In other words, even if air remains inside the circulation flow path 450, including the first tube 411, before the circulation operation S130, the remaining air can be discharged from the circulation flow path 450 by executing the circulation operation S130. In other words, the air in the circulation flow path 450 is replaced with water.

At this time, the third tube 413 is not filled with water. This is because the top of the third tube 413 is blocked by the pressure sensor 430, and the air present in the third tube 413 has no place to escape. Therefore, an air pocket is formed in the third tube 413. In other words, the first tube 411 is filled with water circulating from the water container 300, and an air pocket is formed in the third tube 413.

After the circulation operation S130, the control unit 20 stops the water pump 421, closes the on-off valve 441, and then detects the amount of water stored in the water container 300 (S140).

In step S140, the control unit 20 calculates the volume of water contained in the internal space 300A of the water container 300 based on the voltage output from the pressure sensor 430 to the control unit 20 and the shape information (data table) stored in the memory unit 25. First, the control unit 20 determines the water level contained in the internal space 300A of the water container 300 based on the voltage value output from the pressure sensor 430 to the control unit 20. Next, the control unit 20 refers to the data table to determine the water volume corresponding to the determined water level. In this manner, the control unit 20 calculates the amount of water stored in the water container 300. As described above, in the first embodiment, the control unit 20 corresponds to a water storage amount calculation unit. Note that the water storage amount calculation unit may be provided separately from the control unit 20.

Next, the control unit 20 detects whether or not there is water in the water container 300 (S150).

In the first embodiment, the control unit 20 determines that there is no water in the water container 300 when the voltage output from the pressure sensor 430 to the control unit 20 is a voltage output corresponding to atmospheric pressure (S150: NO). When there is no water in the water container 300, the third tube 413 and the water container 300 are connected by air. Therefore, the pressure sensor 430 detects the atmospheric pressure and outputs a voltage corresponding to the atmospheric pressure to the control unit 20.

When the control unit 20 determines that there is no water in the water container 300 (S150: NO), it notifies the user of the abnormality that the water container 300 is empty by displaying a message, outputting a voice, etc. (S120), and executes the first drainage operation S270 and the second drainage operation S280 described below to end the rice cooking process. Note that the control unit 20 may detect whether the amount of water in the water container 300 is less than a preset water amount, for example a minimum water amount, rather than whether there is no water in the water container 300.

When the control unit 20 determines that there is water in the water container 300 (S150: YES), it determines whether the amount of stored water calculated in step S140 is equal to or greater than the target water supply amount (S160). The target water supply amount is the amount of water required for cooking rice, and is set according to the amount of cooked rice or rice being sent in the currently executed rice cooking process. The amount of cooked rice is input by the user, for example, in the rice cooking instruction. The amount of rice being sent is determined in the rice sending process S20.

If the amount of stored water is less than the target water supply amount (S160: NO), the control unit 20 notifies the user of an abnormality, such as the display of a message and/or audio output, that the water required to perform rice cooking is not contained in the water container 300 (S120), and executes the first drainage operation S270 and the second drainage operation S280 described below, thereby ending the rice cooking process.

If the amount of stored water is equal to or greater than the target water supply amount (S160: YES), the control unit 20 executes the first water supply operation S170. In the first water supply operation S170, the control unit 20 opens the on-off valve 442. This closes the on-off valve 441 and opens the on-off valve 442. Next, the control unit 20 drives the water supply pump 421. This causes the water in the water container 300 to be moved into the second tube 412 by the water supply pump 421, and is supplied from the second tube 412 to the pot 2. In the first water supply operation S170, the control unit 20 supplies water to the pot 2 in an amount less than the target water supply amount, for example, 70 to 90% of the target water supply amount. The amount of water supplied is controlled, for example, by the drive time of the water supply pump 421.

After the first water supply operation S170, the control unit 20 stops the water supply pump 421 and then waits for a certain period of time (S180). During this waiting period, the water in the second pipe 412 moves downward due to its own weight. The certain period of time is set to a time sufficient for the water in the second pipe 412 described above to complete its movement due to its own weight and for the water levels in the water container 300 and the second pipe 412 to stabilize.

It is also possible to forcibly stop the downward movement of water due to its own weight by closing the on-off valve 442 after the first water supply operation S170. However, in the first embodiment, since the on-off valve 442 is a motor valve equipped with a stepping motor, it takes time to open and close. Therefore, during the opening and closing operation of the on-off valve 442, the water in the second tube 412 moves due to its own weight, and the water level in the second tube 412 is not stable. Therefore, in the water supply process of the first embodiment, while the on-off valve 442 is left open after the first water supply operation S170, a certain period of waiting is performed until the water levels in the water container 300 and the second tube 412 stabilize.

After waiting for a certain period of time (S180), the control unit 20 detects the amount of water stored in the water container 300 (S190) in the same manner as in step S140. The control unit 20 may calculate the actual amount of water sent to the pot 2 in the first water sending operation S170 by subtracting the amount of water stored in step S190 from the amount of water stored in step S140.

Next, the control unit 20 executes the second water supply operation S200. The second water supply operation S200 is executed in a manner generally similar to the first water supply operation S170. That is, the control unit 20 drives the water supply pump 421. Note that in the first water supply operation 170, the control unit 20 opens the on-off valve 442 before driving the water supply pump 421, but at the start of the second water supply operation S200, the on-off valve 442 is already open. In the second water supply operation S200, the control unit 20 supplies an amount of water to the pot 2 that is less than the amount of water supplied in the first water supply operation S170. For example, the control unit 20 supplies an amount of water to the pot 2 such that the cumulative amount of water supplied in the first water supply operation S170 and the second water supply operation S200 is 90 to 99 (%) of the target water supply amount.

After the second water supply operation S200, the control unit 20 stops the water supply pump 421 in the same manner as in step S180, and then waits for a certain period of time (S210).

After waiting for a certain period of time (S210), the control unit 20 detects the amount of water stored in the water container 300 (S220) in the same manner as in steps S140 and S190. The control unit 20 may subtract the amount of water stored in step S220 from the amount of water stored in step S190 to calculate the actual amount of water sent to the pot 2 in the second water sending operation S200. The control unit 20 may also subtract the amount of water stored in step S220 from the amount of water stored in step S140 to calculate the cumulative amount of water sent to the pot 2 in the first water sending operation S170 and the second water sending operation S200.

Next, the control unit 20 executes the third water supply operation S230. The third water supply operation S230 is executed in the same manner as the second water supply operation S200. That is, the control unit 20 drives the water supply pump 421. However, in the third water supply operation S230, the control unit 20 supplies an amount of water to the pot 2 that is less than the amount of water supplied in the second water supply operation S200. For example, the control unit 20 supplies 5 to 10 (g) of water to the pot 2.

After the third water supply operation S230, the control unit 20 stops the water supply pump 421, similar to steps S180 and S210, and then waits for a certain period of time (S240).

After waiting for a certain period of time (S240), the control unit 20 detects the amount of water stored in the water container 300 (S250) in the same manner as in steps S140, S190, and S220.

Next, the control unit 20 subtracts the amount of water stored in step S250 from the amount of water stored in step S140 to calculate the cumulative amount of water sent to the pot 2 from the first water sending operation S170 to the third water sending operation S230. The control unit 20 determines whether the calculated cumulative amount of water sent is equal to or greater than the target amount of water sent (S260).

If the cumulative water supply volume calculated in step S260 is less than the target water supply volume (S260: NO), the control unit 20 executes steps S230 to S250 again. On the other hand, if the cumulative water supply volume calculated in step S260 is equal to or greater than the target water supply volume (S260: YES), the control unit 20 executes the first drainage operation S270 and the second drainage operation S280, which will be described later. In other words, the control unit 20 repeats the third water supply operation S230, which supplies a small amount of water to the pot 2, until the cumulative water supply volume becomes equal to or greater than the target water supply volume.

In the first drainage operation S270, the control unit 20 closes the on-off valve 441 and the on-off valve 442. The control unit 20 then drives the air pump 422. This allows external air to be taken in from the other end of the fourth tube 414, and the air is sent to the second tube 412 via the fourth tube 414. The water remaining in the second tube 412 is pushed by the air and drained from the communication port 307 into the water container 300. The control unit 20 then stops the air pump 422. The drive time of the air pump 422 in the first drainage operation S270 is set to a time sufficient for the water remaining in the second tube 412 to be drained into the water container 300.

In the second drainage operation S280, the control unit 20 opens the on-off valve 441 and closes the on-off valve 442. The control unit 20 then drives the air pump 422. This causes external air to be taken in from the other end of the fourth tube 414, and the air is sent to the second tube 412 via the fourth tube 414, and from the second tube 412 to the first tube 411 via the branch position 412C. The water remaining in the first tube 411 is pushed by the air and drained from the communication port 306 into the water container 300. The control unit 20 then stops the air pump 422. The drive time of the air pump 422 in the second drainage operation S280 is set to a time sufficient for the water remaining in the first tube 411 to be drained into the water container 300.

When the second drainage operation S280 is performed, the water pump 421 acts as a resistance to the air sent to the second tube 412 by the air pump 422. Therefore, the air sent to the second tube 412 by the air pump 422 flows into the first tube 411.

In the water supply process described above, in the first water supply operation S170, the control unit 20 supplies water to the pot 2 in an amount that is 70-90% of the target water supply amount. In the second water supply operation S200, the control unit 20 supplies water to the pot 2 in an amount such that the cumulative water supply amount in the first water supply operation S170 and the second water supply operation S200 is 90-99% of the target water supply amount. In the third water supply operation S230, the control unit 20 supplies 5-10 g of water to the pot 2. However, the amount of water supplied to the pot 2 in each water supply process is not limited to the amount described above.

In the water supply process described above, a first water supply operation S170, a second water supply operation S200, and a third water supply operation S230 are performed, and the third water supply operation S230 is performed once or multiple times. In other words, in the water supply process described above, at least three water supply operations are performed. However, the number of times the water supply operations are performed is not limited to at least three times.

For example, the second water supply operation S200 may not be performed. In this case, steps S200 to S220 are not performed, and step S230 (third water supply operation) is performed after step S190. In other words, in this case, at least two water supply operations are performed.

Also, for example, the first water supply operation S170 may be executed only once as the water supply operation. In this case, steps S200 to S260 are not executed, and the first drain operation S270 is executed after step S190. That is, in this case, one water supply operation is executed. Note that in this case, the control unit 20 supplies the target amount of water to the pot 2 in the first water supply operation S170.

In the water supply process described above, the target water supply amount is a value, and the control unit 20 carries out water supply until the cumulative water supply amount is equal to or greater than the target water supply amount. However, a target water supply range may be set instead of the target water supply amount. The target water supply range is a certain range that includes the target water supply amount. In this case, the control unit 20 carries out water supply until, for example, the cumulative water supply amount falls within the target water supply range.

In the first embodiment, the on-off valves 441 and 442 are motor valves that take time to open and close. Therefore, in the water supply process described above, after the first water supply operation S170, the second water supply operation S200, and the third water supply operation S230, the on-off valve 442 is left open and a certain period of time is waited until the water levels in the water container 300 and the second tube 412 stabilize (S180, S210, S240).

However, as described above, the on-off valves 441 and 442 are not limited to motor valves, and may have various known configurations. For example, the on-off valves 441 and 442 may be solenoid valves. Solenoid valves open and close faster than motor valves. Therefore, when the on-off valve 442 is a solenoid valve, after each water supply operation S170, S200, and S230, the control unit 20 can quickly stabilize the water level in the water container 300 and the second pipe 412 by stopping the water supply pump 421 and closing the on-off valve 442. In this case, the control unit 20 may execute the next process (detection of the amount of water stored in the water container 300 (S190, S220, S250)) without performing the above-mentioned waiting (S180, S210, S240) or by shortening the above-mentioned waiting time to a certain time. In this case, in the second water supply operation S200 and the third water supply operation S230, the control unit 20 opens the on-off valve 442 and then drives the water supply pump 421.

In the water supply process described above, in the first drainage operation S270, the control unit 20 drains the water remaining in the second tube 412 into the water container 300 by air taken in from the outside by the air pump 422. However, if the water supply pump 421 is a pump that can control the direction of water supply, such as a gear pump, in the first drainage operation S270, the water supply pump 421 is driven to move the water toward the communication port 307, thereby draining the water remaining in the second tube 412 into the water container 300. In this case, in the first drainage operation S270, the control unit 20 does not need to drive the air pump 422. Also, in this case, the opening and closing valve 442 is opened, allowing air to be taken in from the outside.

In the water supply process described above, the control unit 20 calculates the amount of stored water at each time point and compares it with the target water supply amount, but this is not limited to this. For example, instead of the amount of stored water, the control unit 20 may compare the pressure (e.g., pressure change value) detected by the pressure sensor 430 with a target pressure value corresponding to the target water supply amount.

In the rice cooker 1, the control unit 20 controls the circulation process during temperature detection and the circulation process during ultraviolet irradiation.

Figure 16 is a flow chart showing an example of the circulation process during temperature detection. The circulation process during temperature detection will be explained below with reference to Figure 16.

The control unit 20 compares the temperature information obtained from the temperature detection unit 54 with the set temperature at regular intervals (S410). That is, in the first embodiment, the circulation process during temperature detection is executed at regular intervals. The fixed time in the circulation process during temperature detection is set to an arbitrary time. In the first embodiment, the fixed time is set to, for example, 5 seconds. The fixed time may be zero. In this case, the control unit 20 constantly refers to the temperature information obtained from the temperature detection unit 54. The set temperature is information that is set in advance and stored in the memory unit 25, and can be set to an arbitrary temperature. In the first embodiment, the set temperature is set to, for example, 0 degrees Celsius, at which water located inside the housing 3 of the rice cooker 1, for example, in the water container 300, the first tube 411, and the second tube 412, may freeze.

If the temperature information is higher than the set temperature (S410: NO), the circulation process at the time of temperature detection is terminated without executing the circulation operation S420 described below, and is restarted after a certain period of time.

If the temperature information is equal to or lower than the set temperature (S410: YES), the control unit 20 executes the circulation operation S420. The circulation operation S420 is the same as the circulation operation S130 in the water supply process S30. In the circulation operation S420, the control unit 20 opens the on-off valve 441 and closes the on-off valve 442, and then drives the water supply pump 421. As a result, the water in the water container 300 and the circulation flow path 450 is circulated through the circulation flow path 450 by the water supply pump 421. In other words, the movement of water occurs in the water container 300 and the circulation flow path 450, reducing the possibility of the water freezing.

Figure 17 is a flow chart showing an example of the circulation process during ultraviolet irradiation. The circulation process during ultraviolet irradiation will be explained below with reference to Figure 17.

The control unit 20 determines whether a certain amount of time has passed since the last time ultraviolet light was irradiated from the light source 320 (S610). That is, in the first embodiment, the circulation process during ultraviolet light irradiation is executed at regular intervals. The certain amount of time in the circulation process during ultraviolet light irradiation is set to an arbitrary amount of time. For example, the certain amount of time is set to a time at which bacteria in the water container 300 are predicted to grow to a certain number or more if the water in the water container 300 is left without being irradiated with ultraviolet light.

If a certain amount of time has passed since the last time ultraviolet light was emitted from the light source 320 (S610: YES), the control unit 20 detects whether the water container 300 is attached to the housing 3 (S620), similar to step S110 of the water supply process S30, and detects whether water is present in the water container 300 (S630), similar to step S150 of the water supply process S30.

If the control unit 20 determines that the water container 300 is not attached to the housing 3 (S610: NO), or that there is no water in the water container 300 (S620: NO), it notifies the user of an abnormality (S640) in the same manner as in step S120 of the water supply process S30. In this case, the circulation process during ultraviolet irradiation ends without performing ultraviolet irradiation or circulation operations.

When the control unit 20 determines that the water container 300 is attached to the housing 3 (S610: YES) and that there is water in the water container 300 (S620: YES), it drives the light source 320. This causes the light source 320 to irradiate ultraviolet light toward the internal space 300A of the water container 300 (S650). In other words, ultraviolet light is irradiated from the light source 320 toward the water in the water container 300.

The control unit 20 executes the circulation operation S660 after the light source 320 starts to operate, or simultaneously with the start of operation of the light source 320. The circulation operation S660 is the same operation as the circulation operation S130 of the water supply process S30. In the circulation operation S660, the control unit 20 opens the on-off valve 441 and closes the on-off valve 442, and then drives the water supply pump 421. As a result, the water in the water container 300 and the circulation flow path 450 is circulated through the circulation flow path 450 by the water supply pump 421. In other words, the water moves and is agitated in the water container 300 and the circulation flow path 450, so that ultraviolet rays can be applied to much of the water contained in the water container 300.

The time for which the light source 320 irradiates ultraviolet light in step S650 is, for example, a preset time. The preset time is set to, for example, a time sufficient to kill bacteria in the water container 300.

The set time does not have to be a fixed value and can be variable.

For example, the set time may be longer as the water level in the water container 300 becomes lower. When the water level in the water container 300 becomes lower, the distance from the light source 320 to the water in the water container 300 becomes longer. In such a case, the irradiation time of the ultraviolet light is lengthened. This allows a sufficient amount of ultraviolet light to be applied to the water in the water container 300 even when the distance from the light source 320 to the water in the water container 300 is long.

Also, for example, the control unit 20 may count the cumulative irradiation time of ultraviolet light by the light source 320, and when the cumulative irradiation time exceeds a certain time, the set time may be increased. The certain time may be set to, for example, 1000 hours based on the lifespan of the light source 320. When the lifespan of the light source 320 is approaching, the amount of ultraviolet light irradiated from the light source 320 decreases. In such a case, the irradiation time of ultraviolet light is increased. As a result, even if a light source 320 that irradiates a small amount of ultraviolet light is used, a sufficient amount of ultraviolet light can be applied to the water in the water container 300.

In the first embodiment, the light source 320 is provided above the water container 300. This allows the ultraviolet light irradiated from the light source 320 to be directed toward the internal space 300A of the water container 300 through the opening 303B. However, the light source 320 may be provided somewhere other than above the water container 300. For example, if the water container 300 is made of a material with high transmittance in the ultraviolet region, such as acrylic or glass, the ultraviolet light irradiated from the light source 320 can be directed to the water in the water container 300 even if the light source 320 is provided to the side or below the water container 300.

According to the first embodiment, when the water container 300 and the communication port 306 are connected, the water in the water container 300 flows into the first tube 411, and the air in the first tube 411 is discharged into the water container 300. This allows the air in the first tube to be replaced with water. When at least a portion of the first tube 411 is filled with water flowing from the water container 300, the inside of the third tube 413 becomes an enclosed space filled with gas. The pressure sensor 430 detects the pressure in the third tube 413. In this case, the smaller the amount of water stored in the water container 300, the smaller the detected pressure. Therefore, the amount of water stored in the water container 300 can be measured based on the pressure detected by the pressure sensor 430.

According to the first embodiment, the pressure sensor 430 detects the pressure of a gas. In other words, a pressure sensor for gas can be used. This makes it possible to increase the resolution of the pressure detected by the pressure sensor 430. In other words, it is possible to increase the detection accuracy of the pressure sensor 430.

In the second pipe 412, which is the water flow path between the water container 300 and the pot 2, water moves during the process of sending water to the pot 2 and the process of returning the water remaining in the second pipe 412 to the water container 300. At this time, there is a possibility that air may enter the second pipe 412 mixed with the water. According to the first embodiment, the pressure sensor 430 is provided in the third pipe 413 connected to the first pipe 411, which is different from the second pipe 412. In the first pipe 411, there is no water movement like in the second pipe 412. Therefore, the possibility that water and air enter the first pipe 411 mixedly is lower than the possibility that water and air enter the second pipe 412 mixedly. This makes it possible to reduce the possibility that the detection accuracy of the pressure sensor 430 is affected by the mixture of water and air. As a result, the detection accuracy of the pressure sensor 430 can be maintained at a good level.

According to the first embodiment, the water pump 421 is driven to circulate water in the circulation flow path 450, so that the air in the circulation flow path 450 can be sent to the water container 300. This replaces the air in the circulation flow path 450 with water, and the circulation flow path 450 can be filled with water. Here, the pressure sensor 430 detects the pressure of the gas in the third tube 413 that communicates with the circulation flow path 450. This makes it possible to reduce the possibility that the detection accuracy of the pressure sensor 430 will be affected by the mixture of water and air. As a result, the detection accuracy of the pressure sensor 430 can be maintained at a good level.

According to this configuration, a part of the flow path in the second tube 412 constitutes the circulation flow path 450. Therefore, compared to a configuration in which the flow path in the second tube 412 is a flow path separate from the circulation flow path 450, the effect of the rise in internal pressure that occurs when the water container 300 is connected to the first tube 411 and the second tube 412 can be reduced while keeping the space required to form the water flow path the same.

According to the first embodiment, the water in the water container 300 is circulated in the circulation flow path 450 before being sent to the pot 2. As described above, by circulating the water in the circulation flow path 450, the air in the circulation flow path 450 is replaced with water, so that the detection accuracy of the pressure sensor 430 can be maintained at a good level. In other words, according to the first embodiment, the water in the water container 300 can be sent to the pot 2 with good detection accuracy of the pressure sensor 430. Therefore, the amount of water in the water container 300 and the amount of water reduced in the water container 300 due to the water being sent to the pot 2 can be detected with high accuracy.

According to the first embodiment, the on-off valve 441 is provided between the connection position 411B of the first pipe 411 with the third pipe 413 and the branch position 412C. Therefore, by closing the on-off valve 441, the third pipe 413 can be separated from the path through which the water supply pump 421 sends water from the water container 300 to the pot 2. As a result, the pressure sensor 430 can be detected while the water supply pump 421 is operating. In other words, the change in the amount of water can be detected linearly.

According to the first embodiment, when the air pump 422 is driven, the air sent by the air pump 422 pushes the water in the first tube 411 or the water in the first tube 411 and the second tube 412 back into the water container 300. This makes it possible to reduce water leakage from the first tube 411 and the second tube 412 when the water container 300 is removed from the rice cooker 1.

According to the first embodiment, the on-off valve 442 is closed when the air pump 422 is driven. Therefore, when the air pump 422 is driven, the air sent by the air pump 422 can prevent the water in the second pipe 412 from being sent to the pot 2, and can return the water in the second pipe 412 to the water container 300.

According to the first embodiment, when the air pump 422 is driven, the on-off valve 441 is opened. Therefore, when the air pump 422 is driven, the air sent by the air pump 422 can return the water in the first tube 411 and the second tube 412 to the water container 300 via the circulation flow path 450. This can reduce water falling from the communication ports 306 and 307 when the water container 300 is removed.

If the temperature of the water in the water container 300 is low, there is a risk that the water will freeze. According to the first embodiment, when there is a risk that the water will freeze, the control unit 20 drives the water pump 421 to circulate the water in the circulation flow path 450. This makes it possible to reduce the possibility of the water freezing as described above.

By irradiating the water in the water container 300 with ultraviolet light, the proliferation of bacteria in the water in the water container 300 can be suppressed. Here, when the water in the water container 300 is stationary, the ultraviolet light irradiated by the light source 320 hits only the surface of the water in the water container 300. According to the first embodiment, when the light source 320 irradiates ultraviolet light, the control unit 20 drives the water pump 421 to circulate the water contained in the water container 300 in the circulation flow path 450. As a result, the water in the water container 300 moves, and the water located on the surface is replaced. Therefore, the ultraviolet light irradiated by the light source 320 can be applied to many parts of the water in the water container 300. As a result, the proliferation of bacteria in the water in the water container 300 can be suppressed compared to a configuration in which the water is not circulated.

According to the first embodiment, the inside of the water container 300 is connected to the outside via the opening 303B. Therefore, the inside of the water container 300 can be maintained at atmospheric pressure regardless of the amount of water remaining in the water container 300. In other words, there is little pressure fluctuation due to changes in the amount of water remaining in the water container 300. This allows the pressure sensor 430 to maintain good pressure detection accuracy.

While the water level in the water container 300 can be detected with high accuracy using only the pressure detected by the pressure sensor 430, there are cases where the amount of water in the water container 300 cannot be detected with high accuracy. For example, if the water container 300 has a shape in which the cross-sectional area varies depending on the position in the height direction, it is more difficult to detect the amount of water in the water container 300 than to detect the water level in the water container 300. According to the first embodiment, by using shape information regarding the shape of the internal space of the water container 300, the amount of water stored in the water container 300 is calculated according to the water level in the water container 300, which is calculated based on the pressure detected by the pressure sensor 430. This makes it possible to calculate the amount of water stored in the water container 300 with high accuracy.

Figure 18 is a schematic diagram showing the water container, water supply unit, and pot in a modified example of the rice cooker according to the first embodiment. As shown in Figure 18, the water supply unit 400 of the rice cooker 1 according to the first embodiment may be equipped with a three-way valve 443 instead of the on-off valves 441 and 442. This allows the number of valves equipped in the water supply unit 400 to be reduced.

In the first embodiment, the control unit 20 calculates the volume of water contained in the internal space 300A of the water container 300 based on the water level in the water container 300 and the shape information (data table) stored in the memory unit 25. This calculation of the water volume is not limited to the rice cooker 1 according to the first embodiment, but can be applied to any rice cooker that has a water container 300 and can supply water from the water container 300 to the pot 2.

In other words, the rice cooker to which the above-mentioned application is applied includes a pot, a water container that contains water inside and has a communication port that connects the inside of the water container to the outside, a communication pipe that is connected to the communication port and opens toward the inside of the pot to connect the inside of the water container to the inside of the pot, a water pump that is provided in the communication pipe and moves the water in the communication pipe, a sensor for detecting the water level in the water container, a memory unit that stores shape information related to the shape of the internal space of the water container, and a water storage amount calculation unit that calculates the amount of water stored in the water container based on the water level detected by the sensor and the shape information stored in the memory unit. In this case, the second pipe 412 is an example of a communication pipe, and the pressure sensor 430 is an example of a sensor.

Second Embodiment
19 is a schematic diagram showing a water container, a water supply unit, and a pot in a rice cooker according to a second embodiment of the present disclosure. The rice cooker according to the second embodiment differs from the rice cooker 1 according to the first embodiment in that the first pipe 411 and the second pipe 412 are not connected. The differences from the rice cooker according to the first embodiment will be described below. The points in common with the rice cooker 1 according to the first embodiment are given the same reference numerals, and their description will be omitted in principle, and will be described as necessary.

As shown in FIG. 19, the water container 300 of the rice cooker according to the second embodiment is formed with a communication port 309 in addition to the communication ports 306 and 307. Like the communication ports 306 and 307, the communication port 309 connects the internal space 300A of the water container 300 to the outside of the water container 300. The communication port 309 is an example of a third communication port.

In FIG. 19, the communication ports 306 and 309 are provided on a different surface from the communication port 307, but the communication ports 306, 307, and 309 may be provided on the same surface. Also, in addition to the two opening/closing valves 308 corresponding to the communication ports 306 and 307, an opening/closing valve 308 corresponding to the communication port 309 may be provided.

One end 411A of the first tube 411 is connected to the communication port 306 of the water container 300. The other end 411C of the first tube 411 is connected to the communication port 309 of the water container 300. In this way, the first tube 411 forms a circulation flow path 450. Water circulating from the communication port 309 of the water container 300 passes through the circulation flow path 450, reaches the communication port 306 of the water container 300, and returns to the water container 300. In this way, the water flow path circulates through the circulation flow path 450 and the water container 300.

The water supply unit 400 of the rice cooker according to the second embodiment is equipped with a circulation pump 423. The circulation pump 423 is a machine for supplying water, similar to the water supply pump 421, and is a pump such as a gear pump or a tubing pump that can control the direction of water supply. The circulation pump 423 is provided in the first pipe 411. The operation of the circulation pump 423 is controlled by the control unit 20. When the circulation pump 423 is driven, the water in the water container 300 circulates through the circulation flow path 450.

The water supply section 400 of the rice cooker according to the second embodiment does not include an on-off valve 441, but may include an on-off valve 441. The water supply section 400 of the rice cooker according to the second embodiment includes an on-off valve 442. The on-off valve 442 is provided in the second tube 412 between the water supply pump 421 and the other end 412B.

The fourth pipe 414 branches off from the first pipe 411. One end of the fourth pipe 414 is connected to the first pipe 411. The other end of the fourth pipe 414 is open to the atmosphere. An air pump 422 is disposed in the fourth pipe 414.

In FIG. 19, the connection position 411B between the first pipe 411 and the third pipe 413 is located between the connection position 411D between the first pipe 411 and the fourth pipe 414 and the communication port 306. The circulation pump 423 is located between the connection position 411D and the communication port 309. However, the positional relationship between the connection position 411B, the connection position 411D, and the circulation pump 423 is not limited to the positional relationship described above.

The rice cooking process of the rice cooker according to the second embodiment is generally similar to the rice cooking process of the rice cooker 1 according to the first embodiment. In addition, the water supply process of the rice cooker according to the second embodiment is generally similar to the water supply process of the rice cooker 1 according to the first embodiment.

However, since the rice cooker according to the second embodiment does not have an on-off valve 441, there is no on-off operation of the on-off valve 441. In addition, the rice cooker according to the second embodiment has a circulation pump 423 for circulating water. Therefore, in the circulation operation S130 of the water supply process S30, the control unit 20 does not drive the water supply pump 421, but drives the circulation pump 423.

In the rice cooker according to the second embodiment, the water supply pump 421 is a pump that can control the direction of water supply, such as a gear pump. In the first drainage operation S270, the control unit 20 opens the on-off valve 442. The control unit 20 then drives the water supply pump 421. As a result, the water remaining in the second pipe 412 is drained into the water container 300. Of course, the rice cooker according to the second embodiment may also include a pipe branched off from the second pipe 412 and an air pump provided in the pipe, similar to the rice cooker 1 according to the first embodiment. In this case, the air pump may be driven in the first drainage operation S270, similar to the first embodiment.

In the rice cooker according to the second embodiment, in the second drainage operation S280, the control unit 20 drives the air pump 422. This causes external air to be taken in from the other end of the fourth tube 414, and the air is sent to the first tube 411 via the fourth tube 414. The water remaining in the first tube 411 is pushed by the air and drained into the water container 300. The control unit 20 then stops the air pump 422.

In the rice cooker according to the second embodiment, similar to the rice cooker 1 according to the first embodiment, the control unit 20 executes a circulation process during temperature detection and a circulation process during ultraviolet irradiation.

However, in both the circulation process during temperature detection and the circulation process during ultraviolet irradiation, the control unit 20 does not drive the water pump 421 during the circulation operation, but drives the circulation pump 423. Also, since no on-off valve is provided in the first pipe 411 that constitutes the circulation flow path 450, the control unit 20 does not need to open or close the on-off valve during the circulation operation.

According to the second embodiment, the circulation pump 423 is driven to circulate water in the circulation flow path 450, so that the air in the circulation flow path 450 can be sent to the water container 300. This replaces the air in the circulation flow path 450 with water, and the circulation flow path 450 can be filled with water. Here, the pressure sensor 430 detects the pressure of the gas in the third tube 413 that communicates with the circulation flow path 450. This makes it possible to reduce the possibility that the detection accuracy of the pressure sensor 430 will be affected by the mixture of water and air. As a result, the detection accuracy of the pressure sensor 430 can be maintained at a good level.

According to the second embodiment, the circulation flow path 450 is a flow path separate from the flow path in the second pipe 412. Therefore, compared to a configuration in which the circulation flow path 450 is connected to the flow path in the second pipe 412, it is possible to reduce the influence of the flow of water in the second pipe 412 on the circulation flow path 450.

According to the second embodiment, the water in the water container 300 is circulated in the circulation flow path 450 before being sent to the pot. As described above, by circulating the water in the circulation flow path 450, the air in the circulation flow path 450 is replaced with water, so that the detection accuracy of the pressure sensor 430 can be maintained at a good level. In other words, according to the second embodiment, the water in the water container 300 can be sent to the pot 2 with good detection accuracy of the pressure sensor 430. Therefore, the amount of water in the water container 300 and the amount of water reduced in the water container 300 due to the water being sent to the pot 2 can be detected with good accuracy.

According to the second embodiment, when the air pump 422 is driven, the air sent by the air pump 422 pushes the water in the first tube 411 back into the water container 300. This makes it possible to prevent water from leaking out of the first tube 411 when the water container 300 is removed from the rice cooker 1.

If the temperature of the water in the water container 300 is low, there is a risk that the water will freeze. According to the second embodiment, when there is a risk that the water will freeze, the control unit 20 drives the circulation pump 423 to circulate the water in the circulation flow path 450. This makes it possible to reduce the possibility of the water freezing as described above.

By irradiating the water in the water container 300 with ultraviolet light, the proliferation of bacteria in the water in the water container 300 can be suppressed. Here, when the water in the water container 300 is stationary, the ultraviolet light irradiated by the light source 320 hits only the surface of the water in the water container 300. According to the second embodiment, when the light source 320 irradiates ultraviolet light, the control unit 20 drives the circulation pump 423 to circulate the water contained in the water container 300 in the circulation flow path 450. As a result, the water in the water container 300 moves, and the water located on the surface is replaced. Therefore, the ultraviolet light irradiated by the light source 320 can hit many parts of the water in the water container 300. As a result, the proliferation of bacteria in the water in the water container 300 can be suppressed compared to a configuration in which the water is not circulated.

According to the second embodiment, water can be sent from the water container 300 to the pot 2 via the flow path in the second tube 412 by opening the on-off valve 442.

According to the second embodiment, by closing the on-off valve 442, it is possible to prevent the water in the second pipe 412 on the pot 2 side from the on-off valve 442 from flowing back into the water container 300. This makes it possible to stabilize the amount of water stored in the water container 300.

Third Embodiment
20 is a schematic diagram showing a water container, a water supply unit, and a pot in a rice cooker according to the third embodiment. The rice cooker according to the third embodiment differs from the rice cooker 1 according to the first embodiment in that it does not include a circulation flow path 450. The differences from the rice cooker 1 according to the first embodiment will be described below. The points in common with the rice cooker 1 according to the first embodiment are given the same reference numerals, and explanations thereof will be omitted in principle, and will be described only when necessary.

As shown in FIG. 20, one end 411A of the first tube 411 is connected to the communication port 306 of the water container 300. The other end 411E of the first tube 411 is closed. Note that the connection position 411B of the first tube 411 with the third tube 413 is not limited to the position shown in FIG. 20. For example, the other end 411E of the first tube 411 may be the connection position 411B. In other words, the first tube 411 and the third tube 413 may be connected at the other end 411E.

The water supply section 400 of the rice cooker according to the third embodiment is equipped with an on-off valve 442. The on-off valve 442 is provided between the water supply pump 421 and the other end 412B of the second tube 412.

The water supply section 400 of the rice cooker according to the third embodiment does not include the fourth pipe 414 and the air pump 422, but may include the fourth pipe 414 and the air pump 422. In this case, the fourth pipe 414 may branch off from either the first pipe 411 or the second pipe 412. The water supply section 400 of the rice cooker according to the third embodiment may include two fourth pipes 414 and two air pumps 422, with one of the two fourth pipes 414 branching off from the first pipe 411 and the other of the two fourth pipes 414 branching off from the second pipe 412.

The rice cooking process of the rice cooker according to the third embodiment is generally similar to the rice cooking process of the rice cooker 1 according to the first embodiment. Also, the water supply process of the rice cooker according to the third embodiment is generally similar to the water supply process of the rice cooker 1 according to the first embodiment.

However, since the rice cooker according to the third embodiment does not have an on-off valve 441, there is no opening or closing operation of the on-off valve 441. Also, since the rice cooker according to the third embodiment does not have a circulation flow path 450, the circulation operation is not performed.

In the rice cooker according to the third embodiment, the first drainage operation S270 is performed in the same manner as in the rice cooker according to the second embodiment.

According to the third embodiment, when the water container 300 and the communication port 306 are connected, the water in the water container 300 flows into the first tube 411, and the air in the first tube 411 is discharged into the water container 300. This allows the air in the first tube 411 to be replaced with water. According to the third embodiment, one end 411A of the first tube 411 is connected to the communication port 306, and the other end 411E of the first tube 411 is closed. Therefore, the flow of water in the first tube 411 is reduced, and the possibility of water and air mixing and entering the first tube 411 is reduced. As a result, the detection accuracy of the pressure sensor 430 can be maintained at a good level.

Figure 21 is a schematic diagram showing a water container, a water supply unit, and a pot in a modified example of a rice cooker according to the third embodiment. In the configuration shown in Figure 20, the other end 411E of the first tube 411 is closed. However, as shown in Figure 21, the other end 411E of the first tube 411 may be open to the atmosphere. Also, as shown in Figure 21, an opening/closing valve 444 may be provided between the other end 411E of the first tube 411 and the connection position 411B. Note that the opening/closing valve 444 does not have to be provided. The opening/closing valve 444 is an example of an atmosphere opening valve.

In a rice cooker having the configuration shown in FIG. 21, the control unit 20 controls the opening and closing of the on-off valve 444. For example, when the first pipe 411 and the third pipe 413 are at negative pressure, the on-off valve 444 is opened to return the internal pressure in the first pipe 411 and the third pipe 413 to atmospheric pressure.

21, in which the on-off valve 444 is not provided, the inside of the first tube 411 can be maintained at atmospheric pressure. In the configuration in which the on-off valve 444 is not provided, the other end of the first tube 411 is open to the atmosphere. Therefore, when the water container 300 and the communication port 306 are connected, the water in the water container 300 easily flows into the first tube 411. Therefore, the air in the first tube 411 is easily discharged into the water container 300. This makes it easy to replace the air in the first tube 411 with water.

21, in which the on-off valve 444 is provided, the flow of water in the first tube 411 can be reduced by closing the on-off valve 444. This reduces the possibility of water and air mixing and entering the first tube 411. On the other hand, the pressure in the first tube 411 can be maintained at atmospheric pressure by opening the on-off valve 444. Therefore, when the water container 300 and the communication port 306 are connected, the water in the water container 300 can easily flow into the first tube 411. Therefore, the air in the first tube 411 can easily be discharged into the water container 300. This makes it possible to easily replace the air in the first tube 411 with water.

In addition, any of the various embodiments described above can be combined as appropriate to achieve the effects of each.

Although the present disclosure has been fully described in connection with the preferred embodiment with appropriate reference to the drawings, various modifications and alterations will be apparent to those skilled in the art. Such modifications and alterations are to be understood as included within the scope of the present invention as defined by the appended claims, unless they depart therefrom.

REFERENCE SIGNS LIST 1 Rice cooker 2 Pot 20 Control unit 25 Memory unit 54 Temperature detection unit 300 Water container 303B Opening 306 Communication port (first communication port)
307 Communication port (second communication port)
309 Communication port (3rd communication port)
320 Light source (ultraviolet irradiation part)
411 First pipe 411A One end 411E Other end 412 Second pipe 412C Branch position 413 Third pipe 414 Fourth pipe 421 Water pump 422 Air pump 423 Circulation pump 430 Pressure sensor 441 Opening/closing valve (circulation opening/closing valve)
442 On-off valve (water supply on-off valve)
444 On-off valve (atmospheric on-off valve)
450 Circulation flow path

Claims (19)

A pot and
a water container for storing water therein, the water container having a first communication port and a second communication port for connecting the inside of the water container with the outside;
a first pipe connected to the first communication port to communicate with the inside of the water container;
an on-off valve provided in the first pipe for opening and closing a flow path in the first pipe;
a second pipe connected to the second communication port and opening toward the inside of the pot, thereby communicating between the inside of the water container and the inside of the pot;
a water pump provided in the second pipe to move water in the second pipe;
a third pipe that branches upward from the first pipe between the first communication port and the on-off valve, and in which a sealed air pocket is formed when at least a portion of the first pipe is filled with water; and
a pressure sensor provided in the third pipe and configured to detect a pressure in the third pipe;
A control unit that controls the operation of the water pump and the opening and closing of the on-off valve,
The control unit closes the on-off valve and then drives the water supply pump to supply the water contained in the water container to the pot . A pot and
a water container for storing water therein, the water container having a first communication port and a second communication port for connecting the inside of the water container with the outside;
a first pipe connected to the first communication port to communicate with the inside of the water container;
a second pipe connected to the second communication port and opening toward the inside of the pot, thereby communicating between the inside of the water container and the inside of the pot;
a water pump provided in the second pipe to move water in the second pipe;
a third tube branching upward from the first tube, the third tube having a sealed air pocket formed therein when the first tube is at least partially filled with water;
a pressure sensor provided in the third pipe and configured to detect a pressure in the third pipe;
The second pipe is connected to the first pipe at a branching position between the water pump and the pot,
The first pipe and the second pipe between the branching position and the second communication port constitute a circulation flow path. a circulation on-off valve provided in the first pipe for opening and closing a flow path in the first pipe;
a water supply valve provided between the branching position in the second pipe and the pot, for opening and closing a flow path in the second pipe;
A control unit that controls the operation of the water pump and controls the opening and closing of the water supply valve and the circulation valve,
The control unit is
3. The rice cooker of claim 2, wherein the water supply valve is closed and the circulation valve is opened, and then the water supply pump is driven to circulate the water contained in the water container in the circulation flow path, and then the water supply valve is opened and the circulation valve is closed, and then the water supply pump is driven to send the water contained in the water container to the pot. The rice cooker according to claim 3, wherein the circulation on-off valve is provided between the connection position of the first pipe with the third pipe and the branching position. a fourth pipe branching off from the second pipe between the water supply pump and the water supply on-off valve in the second pipe or between the circulation on-off valve and the branching position in the first pipe;
an air pump that is provided in the fourth pipe and that sends air from the outside to the first pipe and the second pipe via the fourth pipe by being controlled by the control unit;
5. The rice cooker according to claim 3, wherein the control unit drives the air pump to send air to the first pipe and the second pipe when the water pump is stopped. The rice cooker according to claim 5, wherein the control unit closes the water supply valve and opens the circulation valve when driving the air pump. Further comprising a temperature detection unit that detects water temperature or air temperature and outputs temperature information to the control unit,
7. The rice cooker according to claim 3, wherein when the temperature information is lower than a preset temperature, the control unit closes the water supply valve and opens the circulation valve, and then drives the water supply pump to circulate the water contained in the water container through the circulation flow path. The water container further includes an ultraviolet ray irradiation unit that is controlled by the control unit to irradiate ultraviolet rays onto the water contained in the water container,
8. The rice cooker according to claim 3, wherein when the control unit drives the ultraviolet irradiation unit to irradiate ultraviolet rays, the control unit closes the water supply valve and opens the circulation valve, and then drives the water supply pump to circulate the water contained in the water container in the circulation flow path. One end of the first pipe is connected to the first communication port,
The rice cooker according to claim 1 , wherein the other end of the first tube is closed. One end of the first pipe is connected to the first communication port,
2. The rice cooker according to claim 1, wherein the other end of the first pipe is open to the atmosphere. The rice cooker according to claim 10, further comprising an atmospheric opening/closing valve for opening and closing the flow path in the first pipe between the other end of the first pipe and the connection position of the first pipe with the third pipe. The water container has a third communication port formed therein, the third communication port communicating the inside of the water container with the outside.
the first pipe is connected to the first communication port and the third communication port to form a circulation flow path;
The rice cooker according to claim 1 , further comprising a circulation pump provided in the first pipe for moving water in the circulation flow path. A control unit that controls the operation of the water pump and the circulation pump is further provided.
The rice cooker according to claim 12, wherein the control unit drives the circulation pump to circulate the water contained in the water container through the circulation flow path, and then drives the water supply pump to send the water contained in the water container to the pot. a fourth pipe branching from the first pipe;
14. The rice cooker according to claim 13, further comprising: an air pump provided in the fourth pipe, the air pump being controlled by the control unit to send air from the outside to the first pipe via the fourth pipe. Further comprising a temperature detection unit that detects water temperature or air temperature and outputs temperature information to the control unit,
15. The rice cooker according to claim 13, wherein the control unit drives the circulation pump to circulate the water contained in the water container through the circulation flow path when the temperature information is lower than a preset temperature. The water container further includes an ultraviolet ray irradiation unit that is controlled by the control unit to irradiate ultraviolet rays onto the water contained in the water container,
The rice cooker according to any one of claims 13 to 15, wherein the control unit, when driving the ultraviolet irradiation unit to irradiate ultraviolet rays, drives the circulation pump to circulate the water contained in the water container through the circulation flow path. The rice cooker according to any one of claims 9 to 16, further comprising a water supply valve provided in the second pipe for opening and closing the flow path in the second pipe. The rice cooker according to any one of claims 1 to 17, wherein the water container has an opening that connects the inside of the water container with the outside. a storage unit in which shape information regarding the shape of the internal space of the water container is stored;
The rice cooker according to any one of claims 1 to 18, further comprising a water storage volume calculation unit that calculates the amount of water stored in the water container based on the pressure detected by the pressure sensor and the shape information stored in the memory unit.

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