JP7512031B2 - rice cooker - Google Patents

Description

The present invention relates to a rice cooker that allows the pressure inside the inner pot to be freely adjusted using a pressure adjustment means.

Rice cookers that create a pressure state inside the inner pot that is different from atmospheric pressure while cooking or keeping rice warm have been gaining popularity on the market in recent years.

To adjust the pressure inside the inner pot, a pressure adjustment mechanism consisting of a spherical valve or an elastic valve is required, and most products have the mechanism mounted on the inner lid that covers the top of the inner pot. Rice cookers with such pressure mechanism mounted on the inner lid are disclosed in, for example, Patent Documents 1 to 3.

Patent No. 6356089 Patent No. 6121362 Patent No. 3923382

However, in conventional rice cookers, the pressure mechanism parts arranged in the inner lid are arranged in a complex and dense manner, which makes it difficult to clean the pressure mechanism parts and the inner lid after use. In addition, the pressure mechanism parts have the function of setting the pressure inside the inner pot above atmospheric pressure, below atmospheric pressure, or both, and although this is a complex structure that is inherently prone to the adhesion of foreign matter, the pressure mechanism parts come with warnings to prevent the adhesion of foreign matter, resulting in a contradictory configuration.

In view of the above, the present invention aims to provide a rice cooker that allows the pressure inside the inner pot to be freely adjusted and is easy to clean.

In order to achieve the above-mentioned object, the present invention comprises an inner kettle, a main body for housing the inner kettle, an inner lid covering the upper part of the inner kettle, a lid body which is removably attached to the inner lid and covers the upper part of the main body, a steam exhaust means which is removably attached to the lid body and exhausts steam generated in the inner kettle to the outside, and a pressure adjustment means which can freely adjust the pressure inside the inner kettle, wherein a part of the inner surface side of the lid body is concave inside the lid body, and a space is provided which is entirely above the inner kettle when the lid body covers the upper part of the main body , the steam exhaust means is provided in the space so as to be removably attached from the inner surface side of the lid body, and at least a part of the pressure adjustment means is provided in the steam exhaust means.

According to the present invention, the pressure inside the inner pot can be freely adjusted by the pressure adjustment means, the number of parts of the pressure adjustment means arranged on the inner lid can be reduced, and by making a part of the pressure adjustment means together with the steam exhaust means detachable from the inner lid, both the inner lid and the steam exhaust means including the pressure adjustment means can be easily cleaned .

1 is an external perspective view of a rice cooker showing one embodiment of the present invention; FIG. FIG. 2 is a perspective view of the inner lid assembly unit as viewed from above. FIG. 2 is a perspective view of the inner lid assembly unit as viewed from the bottom side of the same. FIG. 2 is an exploded perspective view of the steam exhaust means according to the first embodiment. FIG. 13 is a photograph of the bottom side of the steam exhaust means. FIG. 11 is a view of the inside of the lid seen from the underside of the heat sink of the same embodiment. FIG. 4 is a perspective view showing each part of the steam exhaust means when assembled according to the first embodiment. FIG. 4 is a perspective view showing each part of the steam exhaust means when assembled according to the first embodiment. FIG. 11 is a perspective view of a rice cooker with the lid open, showing a preferred modified example of the rice cooker according to the first embodiment. 12 is an enlarged view of part A in FIG. 11. FIG. 4 is a cross-sectional view of the main parts showing the intake and exhaust paths inside the rice cooker according to the first embodiment. FIG. 2 is a block diagram showing the electrical configuration of the same.

Below, a preferred embodiment of a rice cooker according to the present invention will be described with reference to the accompanying drawings. Note that common parts are designated by common reference numerals throughout these drawings.

First, the overall structure of the rice cooker in this embodiment will be described with reference to Figures 1 and 2. 1 is a cylindrical inner pot with a bottom that contains rice, water, and other food to be cooked. This inner pot 1 is mainly made of aluminum, which has good thermal conductivity, and a heating element 2 made of a magnetic metal plate such as ferritic stainless steel is joined to the outer surface of the main material from the lower side to the bottom. The reason that the heating element 2 is not provided from the center to the upper part of the side of the inner pot 1 is to reduce the weight of the inner pot 1.

The main body 3, which houses the inner pot 1, is made up of an upper frame 4 that forms the top and sides of the main body 3, and an outer frame 5 that forms part of the top, forming the outer shell of the rice cooker, and a bottom plate 6 that covers the bottom of the upper frame 4. The upper frame 4 and bottom plate 6 are made of synthetic resin such as PP, and the outer frame 5 is made of a metal material such as stainless steel.

A concave inner kettle housing section 7 is formed in the center of the main body 3, and the inner kettle housing section 7 is made of a synthetic resin such as PP that is integrated with the upper frame 4. The bottom of the inner kettle housing section 7 is formed of an inner frame 8 made of a synthetic resin such as PET.

The upper end of the inner pot housing 7 is provided with a cord heater 9 (see FIG. 14 ), which is covered with a metal plate 10 such as an aluminum plate having good thermal conductivity. This metal plate 10 is provided as a heat dissipation part at a position facing a gap 11 between the lid 21 and the main body 3, which will be described later, and the cord heater 9 and the metal plate 10 constitute a flange heater as a heat generating means. The lower surface of the flange 12, which extends from the upper end of the inner pot 1 to the entire outer periphery direction, is placed on the upper surface of the metal plate 10, and the inner pot 1 is housed in the inner pot housing 7 in a suspended state. Therefore, in this state, there is almost no gap between the upper end of the inner pot 1 and the inner pot housing 7. However, a partial gap 13 is formed in the metal plate 10 in a plan view so that the handle formed on the flange 12 of the inner pot 1 does not come into contact with the metal plate 10, so that steam is discharged from the gap 13 when rice is cooked with water attached to the outer surface of the inner pot 1. Furthermore, the flange portion 12 of the inner kettle 1 is formed with an outer shape that is equal to or larger than the size of the cord heater 9 so as to cover the cord heater 9, which is the heat generating portion.

A heating coil 15 is disposed on the outer surface of the inner frame 8, on the lower side and bottom of the inner frame 8 facing the heating element 2, as the main heating means for electromagnetic induction heating the inner pot 1. A thermistor type inner pot temperature sensor 16 is disposed on the outer surface of the bottom of the inner pot 1, which detects the temperature of the bottom of the inner pot 1 and mainly controls the heating temperature of the bottom of the inner pot 1 by the heating coil 15.

During cooking and keeping warm, the inner pot 1 is heated by the heating means. During keeping warm, the inner pot 1 is kept at a constant temperature by adjusting the heating coil 15, which serves as the heating means, according to the temperature detected by the inner pot temperature sensor 16 in contact with the outer bottom surface of the inner pot 1. After cooking, the cord heater 9, which serves as the heating means, is heated until the temperature of the rice in the inner pot 1 drops to the keeping warm temperature (from about 100°C to about 73°C) and when the temperature is stable (about 73°C), and heat is radiated from the metal plate part 10 to the gap 13 between the lid 21 and the main body 3, suppressing cooling caused by outside air entering through the gap 13 and heating the inner pot 1. Furthermore, during keeping warm, the inner pot 1 is heated during the period when hot reheating is being performed to reheat the rice in the inner pot 1, and the moisture generated by heating is prevented from condensing on the upper inner surface of the inner pot 1.

21 is a lid that is rotatably attached to the top of the main body 3 and forms the outer shell of the rice cooker together with the main body 3. The lid 21, which opens and closes the upper opening of the inner pot 1, is equipped with a thermistor-type lid temperature sensor 22 that detects the temperature of the inner lid 45 (described later) and a lid heating means 23 such as a cord heater, and the temperature of the inner lid 45 is mainly controlled by the lid heating means 23.

25 is a heating control means for controlling the temperature of heating the bottom and sides of the inner pot 1 and the inner lid 45 of the lid body 21 by detecting the temperature of the inner pot temperature sensor 16 and the lid temperature sensor 22 during cooking and keeping warm. The heating control means 25 receives detection signals from the inner pot temperature sensor 16 and the lid temperature sensor 22, and adjusts the heating of the heating means, namely the cord heater 9, the heating coil 15, and the lid heating means 23.

The heating control means 25 is equipped with an element 26 that drives the heating coil 15. The element 26 that drives the heating coil 15 is heated as the heating coil 15 oscillates. The element 26 that drives the heating coil 15 has an operating temperature, and must be operated below a certain temperature. For this reason, the element 26 is attached to a heat sink 27 made of a material with good thermal conductivity such as aluminum, and is cooled by the wind emitted from a cooling fan 28, which serves as a cooling means, so that the element 26 is operated within the operating temperature range. The cooling fan 28 is located below or to the side of the heat sink 27 attached to the heating control means 25.

A hole 29 is provided on the bottom or side of the rice cooker that will become the product, which exhausts the air emitted from the cooling fan 28 and heated by the radiator 27 to the outside. The heating control means 25 is stored inside the main body 3 that will become the product, but it may be placed anywhere with respect to the inner pot 1, and the hole 29 may also be placed anywhere. However, in recent years, there has been a demand for more compact product designs, so it is preferable to place the heating control means 25 and the cooling fan 28 in approximately opposite positions to the hole 29 that exhausts the air, sandwiching the inner pot 1 between them.

A display operation unit 31 is provided on the front of the top surface of the lid 21. The display operation unit 31 is configured by arranging, on the top of a board 34 mounted inside the lid 21, a switch 33 for starting rice cooking and selecting a rice cooking course, as well as an LCD 32 for displaying the time and the selected rice cooking course, and an LED (not shown) for displaying the current process.

A control panel 35 is disposed above the display operation unit 31 to display button names, etc. This control panel 35 also prevents dust and water from adhering to the electronic components, such as the LCD 32, LEDs, switches 33, and circuit board 34.

In this embodiment, when the switch 33 is operated to start cooking, the bottom and sides of the inner pot 1 are heated by the heating coil 15 and the cord heater 9 based on the temperature of the bottom of the inner pot 1 detected by the inner pot temperature sensor 16 in order to promote water absorption by the rice in the inner pot 1, and the water temperature is maintained at about 45 to 60°C for 15 to 20 minutes to perform soaking cooking. After that, the amount of heat from the heating coil 15 is increased to strongly heat the inner pot 1, and the rice to be cooked in the inner pot 1 is heated to boiling. During this boiling heating, if the bottom temperature of the inner pot 1 reaches 90°C or higher based on the detected temperatures from the inner pot temperature sensor 16 and the lid temperature sensor 22, and the temperature of the lid body 21, especially the inner lid 45, stabilizes at 90°C or higher (temperature rise rate detection), boiling is detected and the amount of heat is reduced to continue boiling heating. In this boiling detection, the inner pot temperature sensor 16 and the lid temperature sensor 22 can confirm that the bottom of the inner pot 1 and the inner lid 45 have both reached 90°C or higher, making it possible to accurately detect when the inside of the inner pot 1 has completely boiled.

If either the bottom of the inner pot 1 or the inner lid 45 reaches an unusual temperature of 120°C or higher, it is determined that an abnormality has occurred, and the amount of heat used for cooking rice is reduced and all operations are stopped in the OFF state, or the temperature is kept warm, to prevent abnormal heating. If either the bottom of the inner pot 1 or the inner lid 45 reaches 90°C or higher and a specified time has passed (e.g., 5 minutes), but the other parts of the bottom of the inner pot 1 and the lid 21 are at a low temperature below 90°C, it is determined that the temperature detection accuracy of either the inner pot temperature sensor 16 or the lid temperature sensor 22 has deteriorated for some reason (dirt, tilt, poor contact, etc.), and the amount of heat used for cooking rice is reduced and all operations are stopped in the OFF state, or the temperature is kept warm, to prevent abnormal heating.

When boiling continues, the lid heating means 23 starts heating the inner lid 45 attached to the lid body 21. Heating of the inner lid 45 is controlled by the temperature detected by the lid temperature sensor 22 so that the temperature of the inner lid 45 is 100 to 110°C. When the temperature of the bottom of the inner pot 1 reaches a predetermined level, it is detected that the rice is cooked and the process moves to steaming. During steaming, the temperature of the inner lid 45 is controlled to prevent the soup from getting on the inside of the upper part of the inner pot 1, and the temperature of the bottom of the inner pot 1 is controlled to keep the temperature high (98 to 100°C) so that the rice does not burn. Then, when the 15 to 20 minutes of steaming is completed, the process moves to keeping it warm.

When keeping warm, the heating coil 15 heats the bottom and lower sides of the inner pot 1, while the lid heating means 23 heats the inner lid 45, which forms the underside of the lid body 21, to a temperature slightly higher than that of the rice. In addition, a flange heater is used to control the temperature of the sides of the inner pot 1 so that the rice does not dry out and does not get too much sauce on it. The temperature of the rice in the inner pot 1 is kept at 70-76°C, but if the two sensors are abnormally high or low relative to each other even during warming, the abnormality is detected and abnormal heating is prevented. The above operations are configured to be performed by the heating control means 25.

A hinge section 36 that connects to the lid body 21 is provided at the rear of the upper frame 4. A hinge spring 37 formed from a torsion coil spring or the like is housed in this hinge section 36. A lid-opening button 38 is provided in an exposed state on the front upper surface of the lid body 21. When this lid-opening button 38 is pressed, the engagement between the lid body 21 and the main body 3 is released, and the elastic force of the hinge spring 37 causes the lid body 21 to automatically open with the hinge section 36 as the center of rotation.

The lid body 21 is composed of an outer lid 41, which is an external component, and an outer lid cover 42, which forms the bottom of the outer lid 41. The outer lid cover 42 is provided with a metal heat sink 43 made of anodized stainless steel or aluminum, and the heat sink 43 is provided with a lid heating means 23. The lid heating means 23 may be an electric heater such as a cord heater, or an electromagnetic induction heating type.

An inner lid 45 made of metal such as stainless steel or aluminum with anodized finish is provided below the heat sink 43. The outer periphery of the inner lid 45, which forms the underside of the lid body 21, is provided with a lid packing 46, which acts as a seal and is made of an elastic material such as silicone rubber or fluororubber that seals the gap between the inner kettle 1 and the inner lid 45, and the lid packing 46 abuts against the upper surface of the flange portion 12 of the inner kettle 1.

The inner lid 45 and the lid gasket 46 are integrated with a gasket base 48, and these inner lid assembly units 49 are removably provided on the inner surface of the outer lid cover 42.

A hole (not shown) is provided in the outer lid cover 42 at the rear so as to face the hole (not shown) provided in the hinge section 36. The hinge shaft 50 provided in the hinge section 36 connects these holes, thereby supporting the main body 3 and the lid body 21 so that they can be opened and closed freely. The hinge spring 37 mentioned above is hooked onto the outer lid cover 42 and constantly urges the lid body 21 in the open direction.

A clamp 51 that is linked to the lid opening button 38 is disposed on the approximate opposite side of the hinge shaft 50 that is the rotation center of the lid body 21. The clamp 51 is supported by the clamp shaft 52 on the outer lid cover 42 and is provided so as to be rotatable around the clamp shaft 52. A clamp receiver 53 (see FIG. 11) that engages with the clamp 51 is provided on the approximate opposite side of the hinge portion 36 of the upper frame 4. The clamp 51 provided on the lid body 21 rotates around the clamp shaft 52 as the central axis and engages with the clamp receiver 53 provided on the main body 3. The main body 3 and the lid body 21 are held in a closed state by the engagement between the clamp 51 and the clamp receiver 53. Conversely, when opening the lid body 21, the lid opening button 38 is pressed to rotate the clamp 51 in the opposite direction, and the engagement between the clamp 51 and the clamp receiver 53 is released.

Next, the configuration of the inner lid assembly unit 49, which essentially corresponds to the inner lid of this embodiment, will be described with reference to Figures 3 and 4. The inner lid assembly unit 49 has holes 54A and 54B for steam discharge and a hole 55 for pressure reduction, which are opened in the inner lid 45. In addition, a convex insertion portion 56 that partially protrudes in the outer circumferential direction is formed in the resin packing base 48 formed in a substantially annular shape. With the lid body 21 open, the insertion portion 56 is inserted into a recess 57 formed on the base end side near the hinge portion 36 on the inner surface of the lid body 21, and the packing base 48 is fitted to the outer lid cover 42, so that the inner lid assembly unit 49 can be attached to a predetermined position on the inner surface of the lid body 21.

When the inner lid assembly unit 49 is attached to the lid 21, a spherical valve 61 provided inside the lid 21 is disposed above the steam exhaust hole 54A, and a valve body 62 (see FIG. 6) also provided inside the lid 21 is disposed above another steam exhaust hole 54B. Also, a cylindrical decompression packing 63 (see FIG. 8 ) protruding downward from the heat sink 43 is disposed above the decompression hole 55. The inner lid assembly unit 49 is detachably provided on the inner surface, i.e., the lower surface side, of the lid 21, and when the lid 21 is closed on the main body 3 with the inner lid assembly unit 49 attached, the lid packing 46 comes into contact with the upper surface of the flange portion 12 of the inner pot 1, and the inner lid assembly unit 49 covers the upper opening of the inner pot 1 without any gaps.

Next, the internal structure of the lid body 21 will be described with reference to Figs. 5 to 7. The lid body 21 is provided with a unitized steam exhaust means 65 that is detachably attached to communicate with the inside of the inner pot 1 and allows steam generated from the inner pot 1 to be exhausted to the outside of the rice cooker. The steam exhaust means 65 may be detachably attached from the top surface side that is the upper surface side of the lid body 21 when the lid body 21 is closed, but it is more preferable to open and form an attachment hole 66 on the inner surface side of the lid body 21 that stands approximately upright away from the upper opening of the inner pot 1 when the lid body 21 is opened, as in this embodiment, and to detachably attach and remove the single steam exhaust means 65 from this attachment hole 66. With this configuration, there is no need to provide an attachment hole for the steam exhaust means 65 on the top surface side of the lid body 21, and the top surface of the lid body 21 can be ensured to have a flat shape without any unevenness. A highly elastic packing 67 similar to the lid packing 46 and the vacuum packing 63 is attached and fixed around the entire periphery of the mounting hole 66, and when the steam exhaust means 65 is attached from the inside side of the lid body 21, the packing 67 fits tightly against the outer surface of the steam exhaust means 65 without any gaps.

Inside the lid 21, a storage space 68 for storing and arranging the steam exhaust means 65 at a desired position is provided by forming the outer lid cover 42 into a partially concave shape from the inner surface side of the lid 21. The lower end opening of the storage space 68 corresponds to the mounting hole 66, and another opening 69 provided at the upper end of the storage space 68 directly communicates with a steam port 70 formed in the outer lid 41 on the top side of the lid 21. In addition, the storage space 68 is provided with a similar through hole, a hole 72 into which a pressure adjustment packing 71 is fitted and a hole 74 into which an opening/closing packing 73 is fitted, but these holes 72 and 74 are always blocked by elastic packings 71 and 73, so that steam and foreign objects do not enter the other interior parts of the lid 21 from the storage space 68 at parts other than the mounting hole 66 and the opening 69. In addition, the mounting hole 66 is formed to be large enough that a hand can be inserted into the storage space 68 from the inside surface of the lid body 21 when the inner lid assembly unit 49 is removed from the lid body 21, so that the inside surface of the storage space 68 can be cleaned without hindrance when maintaining the lid body 21.

The main components of the steam exhaust means 65 are a steam port assembly 81 in which the first pressure regulating means 76, the second pressure regulating means 77, and the third pressure regulating means 78 described below are incorporated into a steam port base 80, a pressure regulating valve holder assembly 82 attached and fixed to the upper part of the steam port assembly 81, and a steam port cap 83 that covers the upper opening of the pressure regulating valve holder assembly 82. Inside the steam exhaust means 65, a hollow cylindrical steam passage 85 is formed with the steam port base 80 as the inlet side and the steam port cap 83 as the outlet side. When the steam exhaust means 65 is accommodated in the accommodation space 68 of the lid body 21, the steam port 70 on the top side of the lid body 21 is positioned at the steam exhaust hole 86 of the steam port cap 83 on the outlet side of the steam passage 85. When the inner lid assembly unit 49 is attached to the inner side of the lid body 21, the aforementioned holes 54A and 54B for steam exhaust are positioned at the inlet side of the steam passage 85, and the interior of the inner kettle 1 and the steam port 70 are connected to each other.

The first pressure adjusting means 76 functions as a pressure adjusting valve assembly that adjusts the pressure inside the inner pot 1 to above atmospheric pressure, and is mainly composed of the valve 61, which is a sphere, a valve holder 88 that holds the valve 61, and a valve case 89 that is partially formed in the pressure adjusting valve holder assembly 82 so as to cover the valve 61 and the valve holder 88. The valve 61 is made of a material with excellent corrosion resistance and may be a part with a certain amount of weight, for example, an austenitic stainless steel ball. In addition, the valve holder 88 is provided with an air hole 90 that connects the inside of the inner pot 1 to the steam passage 85. In other words, the steam generated from the food to be cooked in the inner pot 1 passes through this air hole 90 and is released to the outside air from the steam port 70 through the steam passage 85.

In order to operate the valve 61 at a predetermined timing inside the valve holder 88, a valve opening means 91 serving as a pressure adjusting drive means is incorporated inside the lid body 21. The valve opening means 91 is mainly composed of a pressure adjusting frame 93 that is movable using a solenoid 92 as a drive source, and the above-mentioned pressure adjusting packing 71 attached to one end side of the pressure adjusting frame 93. The valve 61 is constantly pressed by one end of the pressure adjusting frame 93 covered with the pressure adjusting packing 71, and opens the vent hole 90 that communicates with the steam exhaust hole 54A provided in the inner lid 45. On the other hand, when the solenoid 92 is energized and the valve opening means 91 operates, one end of the pressure adjusting frame 93 separates from the valve 61, and the valve 61 closes the vent hole 90. The pressure inside the inner kettle 1 is adjusted to the first set pressure value according to the relationship between the opening area of the vent hole 90 at this time and the weight of the valve 61.

The second pressure adjusting means 77 functions as a safety valve that opens and lowers the pressure in the inner pot 1 when the pressure in the inner pot 1 rises above a set value for some reason, and is configured by housing and holding a valve body 62 and an elastic member 96 in a cylindrical valve holder 95 arranged inside the valve case 89. The elastic member 96 of the second pressure adjusting means 77 biases the valve body 62 in a direction that constantly closes the vent hole 97 formed on the inlet side of the valve holder 95, communicating with the steam exhaust hole 54B provided in the inner lid 45. When the valve 61 of the first pressure adjusting means 76 remains in a state where the vent hole 90 is blocked by a foreign object or the like, the pressure in the inner pot 1 is adjusted to the second set pressure value according to the relationship between the opening area of the vent hole 97 of the second pressure adjusting means 77 and the elastic biasing force of the elastic member 96.

The first pressure regulating means 76 and the second pressure regulating means 77 are both provided in the steam exhaust means 65, not in the inner lid 45, as pressure regulating means that allow the pressure inside the inner kettle 1 to be freely adjusted, but the configuration of the first pressure regulating means 76 and the second pressure regulating means 77 may be reversed, and may not be the configuration described in this embodiment. In addition, either the first pressure regulating means 76 or the second pressure regulating means 77 may be disposed in the steam exhaust means 65, and by providing at least a portion of the pressure regulating means in the steam exhaust means 65, the number of functional parts for pressure regulation in the inner lid 45 can be reduced accordingly.

In this embodiment, a third pressure regulating means 78 and a pressure reducing means 101 are incorporated as pressure regulating means other than the first pressure regulating means 76 and the second pressure regulating means 77. The third pressure regulating means 78 functions as a check valve assembly for returning the pressure in the inner pot 1 from a pressure other than atmospheric pressure to atmospheric pressure, and is configured by housing and holding an elastic member 103 and a valve body 104 in a cylindrical valve holder 102 arranged outside the valve case 89. In addition, in order to operate the valve body 104 of the third pressure regulating means 78 at a predetermined timing, an opening/closing drive means (not shown) separate from the valve opening means 91 is incorporated inside the cover body 21. This opening/closing drive means is mainly configured by an opening/closing frame (not shown) that is movable using a solenoid 105 (see FIG. 14 ) as a drive source, and the above-mentioned opening/closing packing 73 attached to one end side of the opening/closing frame.

The elastic member 103 of the third pressure adjusting means 78 is configured to bias the valve body 104 in a direction to constantly open the vent hole 106 formed on the inlet side of the valve holder 102 in communication with the steam exhaust hole 54A, and when the solenoid 105 of the opening and closing drive means is not energized, the vent hole 106 of the third pressure adjusting means 78 is opened, the steam exhaust means 65 communicates the inside of the inner lid 1 with the outside air, and the pressure inside the inner kettle 1 is kept at the same pressure as atmospheric pressure. On the other hand, when the pressure inside the inner kettle 1 is to be made other than atmospheric pressure, when the solenoid 105 of the opening and closing drive means is energized to operate the opening and closing drive means, one end of the opening and closing frame covered with the opening and closing packing 73 presses the end of the valve body 104 exposed on the outlet side of the valve holder 102 against the elastic biasing force of the elastic member 103, and the valve body 104 closes the vent hole 106. This makes it possible to return the pressure in the inner pot 1 to atmospheric pressure as required, or to introduce a desired pressure other than atmospheric pressure into the inner pot 1.

The steam passage 85 formed inside the steam exhaust means 65 is composed of a first steam passage 85A accommodating the valve 61 and a second steam passage 85B communicating with the first steam passage 85A. The first steam passage 85A is formed by a valve case 89, and a partition wall 108 (see FIG. 2 ) of the valve case 89 having a hole 107 is provided between the first steam passage 85A and the second steam passage 85B. In addition, an insertion hole 109 is formed in the side surface of the valve case 89, through which the pressure adjustment frame 93 covered with the pressure adjustment packing 71 can be inserted, so that the valve 61 can be operated from outside the valve case 89.

As shown in Figure 5, in the present embodiment, when the steam exhaust means 65 is removed from the storage space 68 of the lid body 21, the pressure regulating valve holder assembly 82 is attached and fixed to the steam port assembly 81 by fastening members such as screws 111 so that the steam port cap 83 cannot be disassembled, whereas the pressure regulating valve holder assembly 82 is provided so as to be detachable and disassembleable. As shown in Figures 9 and 10, when assembling the steam exhaust means 65, the valve holder 88 of the first pressure regulating means 76 and the second pressure regulating means 77, which serves as a safety valve, are installed in advance in the steam port base 80, which serves as the base material for the steam port assembly 81. The third pressure regulating means 78, which serves as a check valve assembly, is set in the check valve hole 112 formed in the bottom of the steam port base 80, while the valve 61, which serves as a pressure regulating valve, is set in the valve holder 88. In this state, the pressure regulating valve holder assembly 82 is attached from above the steam port base 80, and finally, the pressure regulating valve holder assembly 82 is screwed and fixed to the steam port assembly 81 with the screw 111.

With the above-mentioned configuration, when the steam exhaust means 65 is disassembled, i.e., when the steam port cap 83 is removed from the pressure regulating valve holder assembly 82, a hand can be inserted through the upper end opening of the pressure regulating valve holder assembly 82 to wipe and clean the entire inner surface of the cylindrical second steam passage 85B. In order to prevent the ball-shaped valve 61 from being lost, the hole 107 formed in the partition wall 108 of the valve case 89 and the insertion hole 109 formed in the side wall are shaped so that the valve 61 cannot slip out. Similarly, not only the components of the first pressure regulating means 76 other than the valve 61, but also the components of the second pressure regulating means 77 and the third pressure regulating means 78 are integrated together so as not to fall off from the steam port assembly 81. This allows the steam exhaust means 65 removed from the cover 21 to be disassembled, and the inside of the steam exhaust means 65 can be washed.

The steam exhaust means 65 is provided with a handle 115 shaped so that it can be grasped with the fingers when attaching or detaching the steam exhaust means 65 to or from the storage space 68 of the lid body 21. The handle 115 is provided so as to protrude from the bottom surface of the steam port assembly 81 toward the top surface of the inner lid 45 when the steam exhaust means 65 and the inner lid assembly unit 49 are attached to the lid body 21. When the inner lid assembly unit 49 is removed from the lid body 21 with the lid body 21 open relative to the main body 3, the exposed handle 115 can be grasped with the fingers to hold the steam exhaust means 65, and the steam exhaust means 65 can be easily removed from the inner surface side of the lid body 21 by pulling it out toward the front. Conversely, when attaching the steam exhaust means 65 to the storage space 68 of the lid body 21, the steam exhaust means 65 can be easily attached from the inside surface of the lid body 21 by holding the steam exhaust means 65 with the exposed handle 115 between the fingers and pushing the steam exhaust means 65 toward the storage space 68.

11 and 12 show a modified example of a rice cooker suitable for providing a handle 115 to the steam exhaust means 65. In these figures, the aforementioned holes 54A and 54B for exhausting steam are formed as a single slit-shaped hole 54. When the inner lid assembly unit 49 is attached to the lid body 21 with the steam exhaust means 65 attached to the storage space 68 of the lid body 21, the handle 115 is inserted through the hole 54 of the inner lid 45 and protrudes toward the inside of the inner pot 1. As a result, for example, when cooking rice with seasoning in the inner pot 1, the handle 115, which is originally used to hold the steam exhaust means 65 with the fingers, can prevent foreign objects such as ingredients placed in the inner pot 1 from sticking to the hole 54 from the inside side of the inner lid 45, and the steam generated from the inner pot 1 can be smoothly guided to the steam exhaust means 65 without adding any extra parts.

As shown in FIG. 12, when the inner lid assembly unit 49 is attached to the lid body 21, the handle 115 of the steam exhaust means 65 does not completely cover the hole 54, and air can be sucked in and out of the inner pot 1 through the gap between the outer periphery of the handle 115 and the hole 54.

Figure 13 shows the intake path S1 and exhaust path S2 inside the rice cooker with arrows. In the figure, 67A is the seal part of the packing 67 that fits tightly to the steam exhaust means 65, and 67B is the seal part of the packing 67 that fits tightly to the inner lid 45. These seal parts 67A and 67B form an airtight structure inside the rice cooker, so that the intake path S1 is connected from the outside of the rice cooker (outside the cooker) → steam port 70 → steam exhaust hole 86 → second steam passage 85B → first steam passage 85A → vent hole 90 → gap between hole 54 and handle 115 → to the inside of the inner pot 1, and the exhaust path S2 is connected from the inside of the inner pot 1 → gap between hole 54 and handle 115 → vent hole 90 → first steam passage 85A → second steam passage 85B → steam exhaust hole 86 → steam port 70 → to the outside of the cooker.

In this embodiment, as a pressure adjusting means for freely adjusting the pressure in the inner pot 1, a pressure reducing means 101 for reducing the pressure in the inner pot 1 to atmospheric pressure or lower with the lid 21 closed on the main body 3 is further provided. The pressure reducing means 101 is composed of a pressure reducing pump 121 as a pressure reducing drive source provided at the rear of the lid 21, and a tubular passage 122 leading from the pressure reducing pump 121 to the pressure reducing hole 55 provided in the inner lid 45. In addition, a solenoid valve 123 (see FIG. 14 ) for opening and closing the base end of the passage 122 is provided inside the lid 21.

When the inner lid assembly unit 49 including the inner lid 45 is attached to the inner surface of the lid body 21, the pressure reducing packing 63 attached to the heat sink 43 elastically deforms and comes into close contact with the upper surface of the inner lid 45, thereby forming a path 122 that connects the pressure reducing hole 55 provided in the inner lid 45 and the pressure reducing pump 121. When the inner kettle 1 is set in the inner kettle housing part 7 of the main body 3 and the lid body 21 with the inner lid assembly unit 49 attached is closed, the lid packing 46 comes into contact with the upper surface of the flange part 12 of the inner kettle 1, and if the valve 61 of the first pressure adjusting means 76 closes the vent hole 90 and the valve body 104 of the third pressure adjusting means 78 closes the vent hole 106, the inside of the sealed inner kettle 1 and the pressure reducing pump 121 communicate with each other through the path 122. When the pressure reducing pump 121 is started in this state, the solenoid valve 123 opens the path 122, and the air in the inner pot 1 is discharged to the outside of the rice cooker through the path 122 and the pressure reducing pump 121, lowering the pressure in the sealed inner pot 1. When the pressure in the inner pot 1 drops below atmospheric pressure by a certain value, the operation of the pressure reducing pump 121 is stopped and the solenoid valve 123 closes the path 122, maintaining the pressure reduced inside the inner pot 1. When the pressure in the inner pot 1 rises due to a slow leak, the solenoid valve 123 similarly opens the path 122 and restarts the pressure reducing pump 121, maintaining the pressure inside the inner pot 1 lower than atmospheric pressure.

When the pressure inside the inner pot 1 is lower than atmospheric pressure and the solenoid 105 of the opening/closing drive means is switched from energized to de-energized, the valve body 104 of the third pressure adjusting means 78 moves away from the vent hole 106, opening the vent hole 106 and connecting the inside of the inner pot 1 to the outside of the rice cooker. This makes it possible to immediately release the negative pressure inside the inner pot 1.

Next, the control system of the rice cooker in this embodiment will be described with reference to Fig. 14. In the figure, 131 is a control means which receives temperature information from the inner pot temperature sensor 16 and the lid temperature sensor 22 and an operation signal from the switch 33 which serves as an operation unit, and controls the heating coil 15, the cord heater 9, and the lid heating means 23 which serves as a lid heater during cooking and keeping rice warm, as well as the solenoids 92, 105, the pressure reducing pump 121, and the solenoid valve 123 mentioned above.

The control means 131 of this embodiment mainly controls the heating coil 15 based on the temperature detected by the inner pot temperature sensor 16 to control the temperature of the bottom of the inner pot 1, and mainly controls the lid heating means 23 based on the temperature detected by the lid temperature sensor 22 to control the temperature of the heat sink 43 and ultimately the inner lid 45. The control means 131 reads a program stored in its own storage means (not shown) which serves as a storage medium, and when, for example, a rice cooking key on the switch 33 is operated, the control means 131 functions as rice cooking control means 132 which executes the rice cooking process in the order of soaking cooking to promote the absorption of water for the rice put into the inner pot 1 from the start of rice cooking, boiling to raise the temperature of the food to be cooked in the inner pot 1 to boiling in a short period of time, continued boiling to keep the food to boil and cook the rice to a dry-up state, and finally steaming to maintain the cooked rice at a high temperature so as not to burn it, and finally finishing the process by steaming, and cooks the rice in the inner pot 1 at a desired pressure, and heats it, and heats it, and heats it, and keeps the rice in the inner pot 1 at a desired pressure, following the rice cooking process, keeps it at a desired temperature.

135 is a heating coil driving means incorporating a high-frequency inverter circuit that receives a control signal from the control means 131 and supplies a predetermined high-frequency current to the heating coil 15. In addition to this, on the output side of the control means 131, there are provided a lid heater driving means 136 that receives a control signal from the control means 131 and drives the lid heating means 23 to heat the heat sink 43 and the inner lid 45, a cord heater driving means 137 that turns the cord heater 9 on or off, a solenoid driving means 138 that turns the solenoids 92 and 105 on or off individually, a pump driving means 139 that drives the pressure reducing pump 121, a solenoid valve driving means 140 that turns the solenoid valve 123 on or off, and a display driving means 142 that drives the display means 141 including the LCD 32 and LEDs described above. During rice cooking by the rice cooking control means 132 and during warming by the warming control means 133, the inner pot temperature sensor 16 and the lid temperature sensor 22 detect the temperatures, and the heating coil 15 heats the bottom to the lower side of the inner pot 1, the cord heater 9 heats the area around the flange 12 of the inner pot 1, and the lid heating means 23 heats the lid 21. After the rice cooking control means 132 finishes cooking rice and the food in the inner pot 1 is cooked as rice, the warming control means 133 automatically switches to warming, and the heating of the inner pot 1 by the heating coil 15 and the cord heater 9 is adjusted based on the temperature detected by the inner pot temperature sensor 16 to keep the rice warm at a specified warming temperature (approximately 70°C to 76°C).

In this embodiment, multiple heating patterns according to the type of food to be cooked and the cooking method are stored in advance in the storage means, and the rice cooking control means 132 selects a specific heating pattern from these multiple heating patterns by operating, for example, the selection key of the switch 33, and then when the rice cooking key is operated to start cooking, the rice cooking control means 132 controls the cord heater 9, heating coil 15, lid heating means 23, solenoids 92, 105, pressure reduction pump 121, and solenoid valve 123 with the selected specific heating pattern, thereby cooking the food to be cooked in the inner pot 1 based on the selected pattern, and finally finishing it into rice. The selection key of the switch 33, which can be manually selected by the user, is a selection means for selecting rice cooking courses classified according to the type of food to be cooked and the cooking method, and when one rice cooking course is selected from multiple rice cooking courses by selecting this selection key, a specific heating pattern corresponding to it is selected. Note that such a selection means is not limited to a selection key, and may include a function in which the rice cooking control means 132 automatically selects a specific heating pattern by default.

Next, the operation of the rice cooker of this embodiment having the above-mentioned configuration will be described. To cook rice with the rice cooker of this embodiment, first put the food to be cooked in the inner pot 1 and set it in the inner pot housing part 7 of the main body 3. Then, with the inner lid assembly unit 49 attached to the inner side of the lid body 21 that has the steam exhaust means 65 housed in the housing space 68 in advance, close the lid body 21 and operate the selection key of the switch 33 to select a specific rice cooking course from among multiple rice cooking courses. Next, when the rice cooking key of the switch 33 is operated, the rice cooking control means 132 incorporated in the control means 131 starts cooking rice based on a specific heating pattern corresponding to the specific rice cooking course.

The rice cooking control means 132 executes the rice cooking process in the order of soaking → boiling → continued boiling → steaming to finish cooking the food in the inner pot 1, and when the pressure inside the inner pot 1 is to be increased to atmospheric pressure or higher during each of these processes, it sends a control signal to the solenoid driving means 138 to energize the solenoid 105 of the opening and closing driving means so that the valve body 104 of the third pressure regulating means 78 closes the vent hole 106, and sends a control signal to the solenoid driving means 138 to energize the solenoid 92 of the valve opening means 91 so that the valve 61 of the first pressure regulating means 76 closes the vent hole 90 by its own weight. As a result, the pressure inside the inner pot 1 is adjusted to the first set pressure value based on the relationship between the opening area of the vent hole 90 and the weight of the valve 61.

In addition, if the valve 61 of the first pressure adjusting means 76 falls into a state where the vent hole 90 remains blocked for some reason while the rice cooking control means 132 is controlling the pressure inside the inner pot 1 to be equal to or higher than atmospheric pressure, the valve body 62 incorporated in the second pressure adjusting means 77 is pushed by the pressure inside the inner pot 1 against the elastic force of the elastic member 96, opening the vent hole 97. Therefore, the pressure inside the inner pot 1 in this case is adjusted to a second set pressure value higher than the first pressure set value based on the relationship between the opening area of the vent hole 97 and the elastic biasing force of the elastic member 96.

On the other hand, when the pressure inside the inner pot 1 is to be lower than atmospheric pressure during the rice cooking process performed by the rice cooking control means 132 and the subsequent warming process performed by the warming control means 133, the rice cooking control means 132 and the warming control means 133 send a control signal to the solenoid drive means 138 to energize the solenoid 105 of the opening and closing drive means so that the valve body 104 of the third pressure adjusting means 78 closes the vent hole 106, and also send a control signal to the pump drive means 139 to operate the pressure reducing pump 121, and further send a control signal to the solenoid valve control means 140 so that the solenoid valve 123 opens the path 122. As a result, the pressure inside the inner pot 1 is adjusted to a third set pressure value lower than atmospheric pressure.

When cooking or keeping warm the food in the inner pot 1 is finished and the lid 21 and the inner lid assembly unit 49 are to be cleaned, the lid 21 is opened from the main body 3 and the inner lid assembly unit 49 is removed from the inner surface of the lid 21 exposed to the front side of the rice cooker. The inner lid 45 of the inner lid assembly unit 49 does not have the first pressure adjustment means 76 to the third pressure adjustment means 78, which serve as pressure adjustment means, and only has the steam exhaust holes 54A, 54B and the pressure reduction hole 55 that communicate with the steam exhaust means 65. Therefore, if at least one of the first pressure adjustment means 76 to the third pressure adjustment means 78 is provided in the steam exhaust means 65 rather than in the inner lid 45, the number of parts of the pressure adjustment means arranged in the inner lid 45 can be reduced accordingly, and the inner lid assembly unit 49 can be easily cleaned by itself. Furthermore, as in this embodiment, by arranging the first pressure regulating means 76, the second pressure regulating means 77, and the third pressure regulating means 78 in the steam exhaust means 65, the number of parts of the pressure regulating means arranged in the inner lid 45 can be reduced as much as possible, making it easier to clean the inner lid assembly unit 49.

After removing the inner lid assembly unit 49 from the inside surface of the lid body 21, the steam exhaust means 65 incorporating the first pressure regulating means 76 to the third pressure regulating means 78 can be easily removed by grasping and pulling out the handle 115 of the steam exhaust means 65 exposed on the front side of the rice cooker with your fingers. The steam exhaust means 65 alone can be disassembled by removing the steam vent cap 83 from the pressure regulating valve holder assembly 82, and the inside of the steam exhaust means 65 can be washed thoroughly by inserting a hand through the upper opening of the pressure regulating valve holder assembly 82 without the first pressure regulating means 76 to the third pressure regulating means 78 falling off.

As described above, in this embodiment, the rice cooker includes the inner pot 1 that contains the food to be cooked, the heating coil 15 as a heating means for heating the inner pot 1, the main body 3 that contains the inner pot 1 and the heating coil 15, the control means 131 that controls the heating coil 15, the inner lid assembly unit 49 as an inner lid that covers the top of the inner pot 1, the lid body 21 that is removably provided with the inner lid assembly unit 49 and covers the top of the main body 3 to close the upper opening of the inner pot 1, the steam exhaust means 65 that is removably provided on the lid body 21 and exhausts steam generated in the inner pot 1 to the outside of the cooker, and the first pressure adjustment means 76 to the third pressure adjustment means 78 and the pressure reduction means 101 as pressure adjustment means that can freely adjust the pressure inside the inner pot 1. The rice cooker is configured such that the first pressure adjustment means 76 to the third pressure adjustment means 78, which are at least a part of the pressure adjustment means, are provided on the steam exhaust means 65.

In this case, the pressure inside the inner kettle 1 can be freely adjusted by the first pressure regulating means 76 to the third pressure regulating means 78 and the pressure reducing means 101, which are pressure regulating means, and the number of parts of the pressure regulating means arranged in the lid body 21 can be reduced. By making the first pressure regulating means 76 to the third pressure regulating means 78, which are part of the pressure regulating means together with the steam exhaust means 65, detachable from the lid body 21, it is possible to easily clean both the lid body 21 and the steam exhaust means 65 including the first pressure regulating means 76 to the third pressure regulating means 78.

The pressure adjustment means in this embodiment includes a first pressure adjustment means 76 that adjusts the pressure in the inner pot 1 to a first set pressure value, and a second pressure adjustment means 77 that adjusts the pressure in the inner pot 1 to a second set pressure value, and the first pressure adjustment means 76 and the second pressure adjustment means 77 are provided in the steam exhaust means 65.

In this case, the first pressure regulating means 76 and the second pressure regulating means 77, which serve as the pressure adjustment means, are both arranged in the steam exhaust means 65, so that the lid body 21 does not have the first pressure regulating means 76 or the second pressure regulating means 77, making it easier to clean the lid body 21.

In addition, in this embodiment, the steam exhaust means 65 is configured to be disassembled, for example, between the pressure regulating valve holder assembly 82 and the steam port cap 83.

In this case, the steam exhaust means 65 can be disassembled after being removed from the lid 21, making it possible to wash the inside completely, and making it easier to clean the steam exhaust means 65, including the first pressure adjustment means 76 to the third pressure adjustment means 78, which serve as pressure adjustment means.

In addition, in this embodiment, the steam exhaust means 65 is configured to be detachably attached from the inner surface side of the lid body 21.

In this case, by making the steam exhaust means 65 detachable from the inside surface of the lid 21 rather than from the top surface of the lid 21, it is possible to eliminate unevenness on the top surface of the lid 21, making it easier to clean the lid 21.

In addition, the steam exhaust means 65 in this embodiment is provided with a knob for holding the steam exhaust means 65 with the fingers, and the inner lid 21 is provided with a hole 54 that communicates with the steam exhaust means 65. When the inner lid assembly unit 49 is attached to the lid body 21 with the steam exhaust means 65 attached to the lid body 21, the handle 115 is inserted through the hole 54 and protrudes toward the inside of the inner kettle 1.

In this case, by holding the steam exhaust means 65 by pinching the handle 115 of the steam exhaust means 65 with the fingers, the steam exhaust means 65 can be easily attached and detached from the inner surface side of the lid body 21. Also, when cooking rice with seasoned ingredients, for example, the handle 115 protruding from the hole 54 of the inner lid 21 toward the inside of the inner pot 1 prevents foreign objects such as ingredients put into the inner pot 1 from sticking to the hole 54 of the inner lid 21, and makes it possible to smoothly guide the steam generated from inside the inner pot 1 to the steam exhaust means 65.

In addition, the pressure adjustment means in this embodiment includes a pressure reducing means 101 that reduces the pressure inside the inner pot 1 to below atmospheric pressure.

In this case, the rice cooker is equipped with a pressure reducing means 101 that reduces the pressure inside the inner pot 1 to below atmospheric pressure as a pressure adjustment means, and both the inner lid 21 and the steam exhaust means 65, including the first pressure adjustment means 76 to the third pressure adjustment means 78, which are pressure adjustment means, can be easily cleaned.

The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, the inner pot 1 of this embodiment includes any container or pot capable of holding the food to be cooked. In addition, a pressure adjustment means having a component configuration or function other than the first pressure adjustment means 76 to the third pressure adjustment means 78 and the pressure reduction means 101 shown in the above embodiment may be incorporated into the rice cooker of the present invention. Furthermore, the disassembly structure of the steam exhaust means 65 may be such that, for example, the steam vent assembly 81, the pressure adjustment valve holder assembly 82, and the steam vent cap 83 can be disassembled separately, or any or all of the parts may be disassembled in a different configuration.

1 Inner pot 3 Main body 21 Lid body 45 Inner lid 49 Inner lid assembly unit
50 Hinge shaft (center of rotation of the lid)
54 Hole 65 Steam exhaust means 68 Storage space (space)
69 Opening 70 Steam port 76 First pressure adjusting means (pressure adjusting means)
77 Second pressure adjusting means (pressure adjusting means)
78 Third pressure adjusting means (pressure adjusting means)
101 Pressure reducing means (pressure adjusting means)
115 Toride

Claims (8)

The inner pot and
A main body that houses the inner pot;
An inner lid that covers the upper part of the inner pot;
A lid body that is provided so as to be freely attached and detached and covers an upper portion of the main body;
A steam exhaust means is provided on the lid body so as to be freely attached and detached, and exhausts steam generated in the inner pot to the outside of the vessel;
A pressure adjusting means capable of freely adjusting the pressure in the inner pot.
A space is provided inside the lid, the inner surface of the lid being partially concave, and the entire space is located above the inner pot when the lid covers the upper part of the main body . The steam exhaust means is provided in the space so as to be detachable from the inner surface of the lid.
A rice cooker characterized in that at least a part of the pressure adjustment means is provided in the steam exhaust means. 2. The rice cooker according to claim 1, wherein an opening provided at an upper end of the space is directly connected to a steam port formed in a top surface side of the lid , and the opening and the steam port are located above the steam exhaust means when the lid is covering an upper part of the main body. The pressure adjusting means includes a pressure reducing means for reducing the pressure in the inner kettle to atmospheric pressure or lower,
3. The rice cooker according to claim 1, wherein the pressure reducing means is provided between the steam exhaust means and a rotation center of the lid body. The pressure adjusting means includes a first pressure adjusting means for adjusting the pressure in the inner pot to a first set pressure value, and a second pressure adjusting means for adjusting the pressure in the inner pot to a second set pressure value,
4. The rice cooker according to claim 1, wherein the first pressure adjusting means and the second pressure adjusting means are provided in the steam exhaust means. 5. The rice cooker according to claim 4, wherein the steam exhaust means is disassembled. The rice cooker according to any one of claims 1 to 5, characterized in that the steam exhaust means has a third pressure regulating means functioning as a check valve assembly for returning the pressure in the inner pot from a pressure other than atmospheric pressure to atmospheric pressure. 7. The rice cooker according to claim 1, wherein the top surface of the lid is flat and has no irregularities. The steam exhaust means is provided with a handle for holding the steam exhaust means with fingers,
The inner lid is provided with a hole communicating with the steam exhaust means,
The rice cooker according to claim 1, characterized in that when the inner lid is attached to the lid body with the steam exhaust means attached to the lid body, the handle is inserted through the hole and protrudes toward the inside of the inner pot.

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