JP7684889B2 - Dishwashers - Google Patents

Description

The present invention relates to a dishwasher.

Patent document 1 discloses an example of a conventional dishwasher. This dishwasher is equipped with a washing tank, a washing means, a water supply valve, a drainage path, a water level detection device, and a control unit.

The washing tank contains tableware as the objects to be washed. The washing tank has a water storage space capable of storing washing water for washing the tableware, and a non-submerged space located above the water storage space in which no washing water is stored. The washing means has a washing/drainage pump and a washing nozzle, and pumps the washing water stored in the water storage space and sprays it toward the tableware. The water supply valve is for supplying the washing water to the water storage space. The drainage path discharges the washing water from the water storage space.

The water level detection device has a water level detection chamber. The water level detection chamber is located at a position different from the drainage path that discharges wash water from the washing tank, and is connected to the water storage space. The water level detection device detects that the water level in the water level detection chamber is at a predetermined water level. The control unit controls the washing means and the water supply valve to execute a washing operation that washes the dishes. The control unit also acquires the detection result of the water level detection device.

The washing operation includes at least a washing process in which tableware contained in the washing tank is washed with washing water, and a rinsing process in which the tableware after the washing process is rinsed with washing water.

This dishwasher further includes a blowing means for blowing air into the non-submerged space. At the start of the rinsing process, the control unit operates the blowing means to pressurize the non-submerged space and the water storage space. This pressurizing force acts to lower the water level in the water storage space while raising the water level in the water level detection chamber. Then, in this state, the control unit opens the water supply valve and supplies water to the water storage space until the water level detection device detects that the water level in the water level detection chamber is at a predetermined water level, thereby reducing the amount of water supplied in the rinsing process. In this way, this dishwasher aims to save water in the rinsing process.

Meanwhile, Patent Document 2 discloses another example of a conventional dishwasher. In this dishwasher, the water level detection device is disposed midway through the drainage path and has a water level detection chamber that communicates with the non-submerged space. Therefore, when the control unit activates the air blowing means at the start of the rinsing process, not only the non-submerged space and the water storage space but also the water level detection chamber is pressurized, so the water level in the water level detection chamber does not rise. As a result, this dishwasher cannot conserve water in the rinsing process in the same way as the dishwasher in Patent Document 1.

JP 2016-54848 A JP 2008-178624 A

However, for the dishwasher of Patent Document 2, there is a demand for some method that is different from that of the dishwasher of Patent Document 1 to conserve water during the rinsing process.

The present invention was made in consideration of the above-mentioned conventional situation, and aims to provide a dishwasher that can reliably save water during the rinsing process in a configuration in which the water level detection chamber is located midway through the drainage path and communicates with the non-submerged space of the washing tub.

The dishwasher of the present invention includes a washing tub for accommodating an object to be washed, the washing tub having a water storage space capable of storing washing water for washing the object to be washed, and a non-submerged space located above the water storage space and not storing the washing water;
A cleaning means for pumping the cleaning water stored in the water storage space and spraying it toward the object to be cleaned;
a water supply valve for supplying the flush water to the water storage space;
A drainage path for discharging the flush water from the water storage space;
a water level detection device that has a water level detection chamber that is disposed in the drainage path and communicates with the non-submerged space, and detects a specific state in which the water level in the water level detection chamber is at a predetermined water level;
A control unit that controls the washing means and the water supply valve to perform a washing operation for washing the object to be washed, and the control unit acquires a detection result of the water level detection device,
The cleaning operation includes a cleaning step of cleaning the object contained in the cleaning tank with the cleaning water;
A rinsing step of rinsing the object to be cleaned with the cleaning water after the cleaning step,
The control unit is
At the start of the cleaning process, a first time from when the water supply valve is opened to when the water level detection device detects the specific state is measured, and a second time shorter than the first time is set based on the first time;
At the start of the rinsing step, when the second time has elapsed since the water supply valve was opened, the water supply valve is closed and the cleaning means is operated.

In the dishwasher of the present invention, the control unit sets a second time that is shorter than the first time based on the first time measured at the start of the washing process, so that the amount of water supplied to the rinsing process can be reduced with high reliability by using the second time.

Let us now consider a case in which, instead of the second time, a uniform open duration is preset during the manufacturing or shipping stage of the dishwasher, and the control unit opens the water supply valve at the start of the rinsing process, and closes the water supply valve when the open duration has elapsed, thereby reducing the amount of water supplied to the rinsing process.

In this case, the water supply pressure of the water supply source and the length of the water supply pipes vary depending on where the dishwasher is installed, so the amount of water supplied during the rinsing process, which is determined by the duration the valve is open, is also likely to vary depending on where the dishwasher is installed. In this case, the amount of water supplied may be more than expected or less than expected, causing poor rinsing during the rinsing process and making it necessary to repeat the rinsing process, which may make it difficult to save water.

In this regard, the dishwasher of the present invention measures the first time during the washing process each time the dishwasher is installed and sets the second time based on the first time, so that the amount of water supplied during the rinsing process, which is determined by the second time that accurately reflects the conditions of the installation location, is unlikely to be more or less than expected.

Therefore, in the dishwasher of the present invention, the water level detection chamber is positioned in the middle of the drainage path and is connected to the non-submerged space of the washing tub, which makes it possible to reliably save water during the rinsing process.

It is preferable that the dishwasher of the present invention further includes a heater located in the water storage space for heating the wash water during the washing process. It is also preferable that the rinsing process is a water rinsing process in which the objects to be washed after the washing process are rinsed with unheated wash water while the heater is not in operation.

At the start of the water rinsing process, for example, if the water supply pressure decreases and the second time has passed since the water supply valve was opened, there is a rare risk of a malfunction in which the heater is exposed due to an insufficient amount of cleaning water stored in the water storage space. Even in this case, since the heater is not operating during the water rinsing process, no malfunction due to abnormal heating of the heater occurs.

At the start of the rinsing process, it is desirable for the control unit to close the water supply valve and activate the cleaning means when the water level detection device detects a specific state before the second time has elapsed since the water supply valve was opened.

When the water supply pressure decreases at the start of the washing process due to the use of a faucet or the like connected to a water supply source separate from the water supply valve, the measured first time is likely to become longer. In this case, if the water supply pressure returns to normal at the start of the rinsing process, there is a risk that the amount of water supplied will be excessive until the second time set based on such a first time has elapsed, and if no measures are taken, there is a risk of problems such as overflowing caused by the excessive amount of water supplied. In this regard, in this dishwasher, when the water level detection device detects a specific state at the start of the rinsing process before the second time has elapsed after the water supply valve is opened, the control unit determines that there is a high possibility that the amount of water supplied in the rinsing process will be excessive, and closes the water supply valve. As a result, this dishwasher can suppress problems such as overflowing caused by an excessive amount of water supplied.

It is preferable that the cleaning means has a pump that sucks in and discharges cleaning water stored in the water storage space, and a nozzle that sprays the cleaning water discharged by the pump toward the object to be cleaned in the non-submerged space. It is preferable that one end of the drainage path is provided in a position that receives the discharge pressure of the pump when the pump is operated and the nozzle sprays cleaning water. It is also preferable that the control unit stops the pump and reopens the water supply valve if the water level detection device does not detect a specific state when the pump is operated and the nozzle starts spraying cleaning water at the start of the rinsing process.

If the water supply pressure decreases at the start of the rinsing process due to the use of a water faucet or the like connected to a water supply source separate from the water supply valve, the amount of water supplied from the opening of the water supply valve until the second time has elapsed may be insufficient, and if no measures are taken, problems such as noise caused by air being trapped in the pump due to insufficient water supply may occur. In this regard, in this dishwasher, the discharge pressure of the pump that operates at the start of the rinsing process acts on one end of the drainage path, causing the water level in the water level detection chamber to rise. Then, if the water level detection device does not detect a specific state when the pump operates and the nozzle begins to spray cleaning water at the start of the rinsing process, the control unit determines that there is a high possibility that the pump will continue to operate with an insufficient amount of water supplied during the rinsing process, and opens the water supply valve. As a result, this dishwasher can suppress problems such as pump noise caused by insufficient water supply.

It is desirable for the control unit to reopen the water supply valve at the start of the rinsing process and then continue to keep the water supply valve open until the water level detection device detects a specific state.

In this case, the water supply valve is opened to prevent the pump from continuing to operate with an insufficient amount of water supplied during the rinsing process, and then the water supply valve is kept open until the water level detection device detects a specific state, thereby preventing the pump from repeatedly starting and stopping. As a result, this dishwasher can reduce problems such as pump noise caused by an insufficient amount of water supplied, and can also prevent the time required for the rinsing process from becoming longer, thereby improving user comfort.

The dishwasher of the present invention has a water level detection chamber located in the middle of the drainage path and connected to the non-submerged space of the washing tub, which makes it possible to reliably conserve water during the rinsing process.

FIG. 1 is a schematic cross-sectional view of a dishwasher according to an embodiment of the present invention. FIG. 2 is a front view of the pump of the dishwasher according to the embodiment, showing the internal structure of the pump in partial cross section. FIG. 3 is a rear view of the pump housing alone of the pump, as viewed from the rear. FIG. 4 is a block diagram of the dishwasher according to the embodiment. FIG. 5 is a perspective view of a water level detection device in the dishwasher according to the embodiment. FIG. 6 is a cross-sectional view of the water level detection device. FIG. 7 is a flow chart of the cleaning operation program. FIG. 8 is a flow chart of the cleaning operation program. FIG. 9 is a flow chart of the cleaning operation program.

The following describes an embodiment of the present invention with reference to the drawings.

(Example)
As shown in Fig. 1, the dishwasher 1 of the embodiment is an example of a specific embodiment of the dishwasher of the present invention. The dishwasher 1 is a front pull-out type installed under a countertop CT1 of a system kitchen.

In this embodiment, the side that a user using the system kitchen faces the housing 9, i.e., the left side of the paper in FIG. 1, is defined as the front of the housing 9, and the opposite side, the right side of the paper in FIG. 1, is defined as the rear of the housing 9. In addition, the side that the user faces to the left when facing the housing 9, i.e., the back side of FIG. 1, is defined as the left side of the housing 9, and the side that the user faces to the right, i.e., the front side of the paper in FIG. 1, is defined as the right side of the housing 9. The front-rear, left-right, and up-down directions shown in FIG. 2 and subsequent figures are all displayed in correspondence with FIG. 1.

<Housing, cleaning tank and lid>
The dishwasher 1 comprises a housing 9 , a washing tub 7 and a lid 8 .

The housing 9 is generally box-shaped. The top of the housing 9 is covered with a top plate CT1. The housing 9 has a housing opening 9H. The housing opening 9H opens a wide area from the top to the bottom of the front of the housing 9, connecting the inside of the housing 9 to the outside.

The cleaning tank 7 is housed in the housing 9. The position of the cleaning tank 7 shown in FIG. 1 is the housed position. A slide rail mechanism (not shown) is disposed between the side of the cleaning tank 7, which is a roughly box-shaped body, and the inner wall surface of the housing 9. Although not shown, the slide rail mechanism allows the cleaning tank 7 to slide relative to the housing 9.

The cleaning tank 7 has a tank opening 7H. The tank opening 7H opens the top of the cleaning tank 7. A handle 7G is provided at the top end of the front of the cleaning tank 7.

When the user grasps the handle 7G and manually slides the cleaning tank 7 from the storage position to the front of the housing 9, the cleaning tank 7 is pulled out forward from the housing opening 9H of the housing 9 (not shown). In addition, when the user manually slides the pulled-out cleaning tank 7 to the rear of the housing 9, the cleaning tank 7 returns to the storage position.

The lid 8 is located at the top of the housing 9 and can close and open the tank opening 7H of the cleaning tank 7. The lid 8 moves up and down in conjunction with the sliding of the cleaning tank 7 by a linkage mechanism (not shown) between the position shown in FIG. 1 and a position (not shown) that rises from the position shown in FIG. 1 and allows the cleaning tank 7 to slide.

When the cleaning tank 7 is in the storage position, it closes the housing opening 9H, and the tank opening 7H is closed by the lid 8.

Although not shown in the figure, when the washing tub 7 is pulled out from the housing 9, the lid 8 remaining inside the housing 9 opens the tub opening 7H exposed to the outside of the housing 9. This allows the user to place tableware TW1 in the washing tub 7 or remove tableware TW1 from the washing tub 7 through the tub opening 7H.

Tableware TW1 is, for example, tableware such as bowls, plates, and glasses, and eating and drinking utensils such as chopsticks, spoons, and forks. Tableware TW1 is an example of the "item to be washed" of the present invention.

A dish basket 70 is placed in the washing tank 7. Tableware TW1 is placed in the dish basket 70. A rotating body 60 is provided below the dish basket 70 in the washing tank 7. The rotating body 60 has an arm shape that protrudes radially outward from a rotation axis X1 that extends vertically, and is rotatable around the rotation axis X1.

The washing tank 7 has a water storage space A1 and a non-submerged space A2. The water storage space A1 is a space located below the dish basket 70 and the rotating body 60, and is capable of storing washing water for washing the tableware TW1. The non-submerged space A2 is a space located above the water storage space A1, and does not store washing water. The dish basket 70 and the rotating body 60 are located in the non-submerged space A2.

<Water supply pipes, water supply valves, nozzles, pumps and drain pipes>
The dishwasher 1 further includes a water supply pipe P1, a water supply valve 69, a nozzle 61, a pump 62, and a drain pipe P2. The nozzle 61 and the pump 62 are an example of the "cleaning means" of the present invention. The drain pipe P2 is an example of the "drain path" of the present invention.

The water supply pipe P1 and the water supply valve 69 are provided inside the housing 9. The water supply pipe P1 supplies water to be used as cleaning water from a water supply source (not shown) provided outside the dishwasher 1 to the water storage space A1 of the cleaning tub 7. The water supply valve 69 is an electromagnetic valve that opens and closes the water supply pipe P1 to switch between supplying and stopping cleaning water to the water storage space A1.

The nozzle 61 has multiple discharge holes arranged in a row on the upper surface of the rotor 60. The nozzle 61 can spray cleaning water into the cleaning tank 7 from the multiple discharge holes while rotating together with the rotor 60.

The pump 62 has a pump housing 62H, a blade member 62P rotatably supported within the pump housing 62H, and an electric motor 62M that rotates and drives the blade member 62P.

As shown in Figures 2 and 3, the pump housing 62H has an intake port 62C, a first discharge port 62H1, and a second discharge port 62H2.

The suction port 62C protrudes forward from the center of the front wall 62F of the pump housing 62H in a cylindrical shape. In FIG. 2, forward is the direction from the back of the page to the front. In FIG. 3, forward is the direction from the front of the page to the back.

The first discharge port 62H1 protrudes leftward from the upper part of the peripheral wall 62W of the pump housing 62H in a cylindrical shape. The second discharge port 62H2 protrudes leftward from the lower part of the peripheral wall 62W of the pump housing 62H in a cylindrical shape.

As shown in FIG. 2, the portion of the peripheral wall 62W of the pump housing 62H that is located between the first discharge port 62H1 and the second discharge port 62H2 in the circumferential direction is the induction restriction portion 62D. The thickness of the peripheral wall 62W of the induction restriction portion 62D is thicker on the inner circumferential side so that the inner surface of the induction restriction portion 62D is close to the outer circumferential edge of the blade member 62P.

As shown in FIG. 3, in the pump housing 62H, the suction pressure region E1 formed near the suction port 62C and the discharge pressure region E2 formed near the second discharge port 62H2 are connected by a groove portion 62G recessed in the front wall 62F of the pump housing 62H.

As shown in FIG. 1, the intake port 62C is connected to the bottom of the water storage space A1. A food residue filter 67 is disposed above the connection with the intake port 62C in the water storage space A1.

The first outlet 62H1 is connected to the injection pipe 60A. The injection pipe 60A rotatably supports the rotor 60 and is connected to the inside of the rotor 60. The second outlet 62H2 is connected to one end P2A of the drain pipe P2.

As shown in FIG. 2, the electric motor 62M rotates the blade member 62P in the forward direction R1, i.e., counterclockwise on the paper surface of FIG. 2, thereby operating the pump 62 in the forward direction. When operating in the forward direction, the pump 62 discharges cleaning water drawn from the water storage space A1 via the suction port 62C from the first discharge port 62H1 to the injection pipe 60A.

At this time, the guide restriction portion 62D prevents the cleaning water guided to the first outlet 62H1 by the blade member 62P rotating in the forward direction R1 from being further guided toward the second outlet 62H2.

As shown in FIG. 3, the groove 62G connects the suction pressure region E1 and the discharge pressure region E2, so that when the blade member 62P rotates in the forward direction R1, a portion of the groove 62G is formed where the suction pressure and the discharge pressure cancel each other out and no pressure is generated. This makes it difficult for the wash water in the pump housing 62H to be guided toward the second discharge port 62H2.

As a result, when the pump 62 is operating in the forward direction, the cleaning water in the pump housing 62H is prevented from being discharged from the second discharge port 62H2. Even in this case, a discharge pressure that does not cause a continuous flow of cleaning water acts on the drain pipe P2 from the second discharge port 62H2 via one end P2A of the drain pipe P2. The cleaning water that is stagnating in the drain pipe P2 is pushed up by the discharge pressure.

In other words, one end P2A of the drain pipe P2 is located at a position that receives the discharge pressure of the pump 62 when the pump 62 is operating in the forward direction and the nozzle 61 sprays cleaning water.

On the other hand, as shown in FIG. 2, the electric motor 62M rotates the blade member 62P in the reverse direction R2, i.e., clockwise as viewed in FIG. 2, causing the pump 62 to operate in reverse. When the pump 62 operates in reverse, it discharges the cleaning water drawn in from the water storage space A1 via the suction port 62C from the second discharge port 62H2 into the drain pipe P2.

At this time, the guide restriction portion 62D prevents the cleaning water guided to the second outlet 62H2 by the blade member 62P rotating in the reverse direction R2 from being further guided toward the first outlet 62H1.

As shown in FIG. 1, the drain pipe P2 extends rearward within the housing 9 away from the pump 62, then extends upward along the rear wall of the washing tank 7 and makes a U-turn. The drain pipe P2 then extends downward along the rear wall of the housing 9, then makes a U-turn to form a drain trap, and then extends outside the dishwasher 1.

When the pump 62 operates in the normal direction, the cleaning water stored in the water storage space A1 is sucked into the pump housing 62H via the suction port 62C and discharged from the first discharge port 62H1. The nozzle 61 sprays the cleaning water discharged from the first discharge port 62H1 toward the tableware TW1 in the non-submerged space A2. The sprayed cleaning water is stored in the water storage space A1, and is repeatedly supplied to the nozzle 61 by the pump 62.

On the other hand, when the pump 62 operates in reverse, the cleaning water discharged from the water storage space A1 through the suction port 62C and the second discharge port 62H2 is discharged outside the dishwasher 1 through the drain pipe P2.

<Heater, temperature sensor, drying fan and water level detector>
The dishwasher 1 further includes a heater 63 , a temperature sensor 63S, a drying fan 68 and a water level detection device 10 .

The heater 63 is disposed at the bottom of the water storage space A1. The drying fan 68 is attached to the rear wall of the cleaning tank 7. The temperature sensor 63S is disposed directly below the heater 63 on the underside of the bottom wall of the cleaning tank 7.

The heater 63 heats the cleaning water stored in the water storage space A1 or the air in the cleaning tank 7.

The temperature sensor 63S detects the temperature of the cleaning water stored in the water storage space A1 or the air in the cleaning tank 7 near the heater 63.

The drying fan 68 rotates while the heater 63 is in operation to send heated air into the washing tank 7 to dry the tableware TW1. The air sent into the washing tank 7 by the drying fan 68 is exhausted to the outside of the dishwasher 1 via an exhaust passage 79 that opens at the front of the washing tank 7 and communicates with the non-submerged space A2 of the washing tank 7.

The water level detection device 10 is a float-type sensor that detects the level of the cleaning water in the cleaning tank 7. The water level detection device 10 is attached to the lower part of the rear wall of the cleaning tank 7.

The water level detection device 10 has a water level detection chamber 20A inside. The water level detection chamber 20A is located midway through the drain pipe P2. The water level detection chamber 20A is also connected to the non-submerged space A2 via a communication path P3.

The side of the drain pipe P2 facing the pump 62 with respect to the water level detection chamber 20A is the first drain pipe P21. The side of the drain pipe P2 facing the water level detection chamber 20A with respect to the opposite side of the pump 62 is the second drain pipe P22.

In FIG. 1, to make the drawing easier to see, the position of the water level detection device 10 is illustrated farther from the rear wall of the washing tank 7 than it actually is, and the communication path P3 is illustrated as being longer in the front-to-rear direction than it actually is.

The water level detection device 10 detects a specific state in which the water level in the water level detection chamber 20A is at a predetermined water level. The specific configuration of the water level detection device 10 will be described in detail later with reference to Figures 5 and 6.

<Control unit and input/output unit>
As shown in FIG. 4, the dishwasher 1 further includes a control unit C1, a drive circuit C1D, and an input/output unit 40.

The control unit C1 is an electronic circuit unit that includes a CPU, a memory unit C1M, and an interface circuit (not shown).

The memory unit C1M is composed of memory elements such as ROM and RAM. The memory unit C1M stores various programs executed by the control unit C1 to operate the dishwasher 1, such as the cleaning operation programs shown in Figures 7 to 9. The memory unit C1M also stores various information such as setting information for the dishwasher 1, and initial setting information for executing the various programs, as needed.

The control unit C1 obtains the detection result from the temperature sensor 63S, and based on the detection result, determines the temperature of the cleaning water stored in the water storage space A1 and the temperature of the air in the cleaning tank 7.

The control unit C1 also obtains the detection result from the water level detection device 10, and determines the water level of the flush water stored in the water storage space A1 based on the detection result. At this time, the control unit C1 takes into consideration that one end P2A of the drain pipe P2 is located in a position that receives the discharge pressure of the pump 62 when the pump 62 is operating in the forward direction, as described below.

Furthermore, the control unit C1 receives detection signals from sensors (not shown), such as a position sensor that detects whether the cleaning tank 7 is in the storage position, and a lock sensor that detects whether the cleaning tank 7 is locked in the storage position.

The control unit C1 then outputs a control signal via the drive circuit C1D to control the operation of the pump 62, water supply valve 69, heater 63 and drying fan 68, thereby performing a washing operation to wash the tableware TW1.

As shown in FIG. 1, the input/output unit 40 is disposed at the upper end of the front side of the cleaning tank 7. The input/output unit 40 has a number of buttons (not shown) that allow the user to perform input operations. The input/output unit 40 also has lamps and display elements that can display numbers, letters, etc. to convey various information to the user.

As shown in FIG. 4, the input/output unit 40 transmits user input operations to the control unit C1 and displays information transmitted from the control unit C1.

<Details of the water level detection device>
The water level detection device 10 has a tank 20, an inlet 21 and an outlet 22 shown in FIGS. 5 and 6, and a water level detection chamber 20A, a float guide 23, a float 30 and a water level sensor 11 shown in FIG.

As shown in Figures 5 and 6, the tank 20 has a tank body 25, a top lid 29, and a cap 29C. In this embodiment, the tank body 25, the top lid 29, and the cap 29C are each resin molded products manufactured by injection molding of a thermoplastic resin, etc.

The tank body 25 has an integral side wall 27 and a bottom wall 26. The side wall 27 has a generally rectangular cylindrical shape that extends vertically and includes a tank front wall 27A, a tank rear wall 27B, a tank left wall 27L, and a tank right wall 27R. The bottom wall 26 is connected to the lower end of the side wall 27.

As shown in FIG. 6, a pedestal 24 is formed in the center of the upper surface of the bottom wall 26. The pedestal 24 protrudes upward in a cylindrical shape centered on an axis X23 that extends in the vertical direction. The inside of the pedestal 24 is closed by a partition wall.

A lower limit stopper 26S is formed around the periphery of the base 24. The lower limit stopper 26S is a number of ribs that protrude from the outer peripheral surface of the base 24 in the radially outward direction of the axis X23.

A circular inlet 21 is drilled in the lower part of the tank right wall 27R. In FIG. 6, the tank right wall 27R is located on the front side of the page, so the inlet 21 is shown by a two-dot chain line. As shown in FIG. 5, the inlet 21 protrudes cylindrically to the right from the tank right wall 27R. As shown in FIGS. 1 and 5, the inlet 21 is connected to the first drain pipe P21 on the pump 62 side of the drain pipe P2.

As shown in Figures 5 and 6, a circular hole-shaped outlet 22 is drilled in the upper part of the tank left wall 27L. As shown in Figure 5, the outlet 22 protrudes leftward from the tank left wall 27L in a cylindrical shape. As shown in Figures 1 and 5, the outlet 22 is connected to the second drain pipe P22 on the opposite side of the drain pipe P2 from the pump 62.

As shown in Figures 5 and 6, the top cover 29 fits onto the upper edge of the side wall 27 with a sealing member such as a sealant or elastic seal ring (not shown) interposed therebetween.

As shown in FIG. 6, a water level detection chamber 20A is defined inside the tank 20. The water level detection chamber 20A is a space surrounded by a bottom wall 26, a side wall 27, and a top cover 29. The water level detection chamber 20A is located midway along the drain pipe P2, with the inlet 21 connected to the first drain pipe P21 and the outlet 22 connected to the second drain pipe P22.

A float guide 23 is formed in the center of the underside of the top lid 29. The float guide 23 protrudes downward in a cylindrical shape centered on the axis X23. The inside of the float guide 23 is closed by a partition wall. The internal space above the partition wall in the float guide 23 is used as a sensor storage section 23S.

The float guide 23 extends vertically within the water level detection chamber 20A, and its lower end is fitted into the base 24. An upper limit stopper 29S is formed around the upper end of the float guide 23. The upper limit stopper 29S is a number of ribs that protrude radially outward from the outer circumferential surface of the upper end of the float guide 23 about the axis X23.

The cap 29C is fastened to the top cover 29 by the screw 29B in a state in which it closes the sensor storage section 23S from above.

A communication port 28 is drilled in the front of the top cover 29 and protrudes upward. The upper part of the communication port 28 is connected to a connection part 28C. As shown in Figures 5 and 6, the connection part 28C protrudes forward in a cylindrical shape.

The tank 20 has a fixed protrusion 20D that protrudes forward from the tank front wall 27A, and a fixed piece 20E that protrudes upward from the top lid 29.

As shown in FIG. 6, the rear wall of the cleaning tank 7 is formed with a connection recess 7F, a fixing recess 7D located below the connection recess 7F, and a fastening portion 7E located above the connection recess 7F.

The tank 20 is attached to the rear wall of the cleaning tank 7 by fitting the connection portion 28C into the connection recess 7F, fitting the fixing protrusion 20D into the fixing recess 7D, and fastening the fixing piece 20E to the fastening portion 7E by the screw 20B.

A communication hole 7C is provided in the rear wall of the cleaning tank 7 in the front-to-rear direction. The communication hole 7C connects the lower end of the connection part 28C, which is fitted into the connection recess 7F, to the non-submerged space A2. The communication opening 28, the connection part 28C, and the communication hole 7C form a communication path P3 that connects the water level detection chamber 20A to the non-submerged space A2.

When an excess of cleaning water flows into the water level detection chamber 20A, the communication path P3 can discharge a portion of the cleaning water into the non-submerged space A2. The communication path P3 also serves as an air vent that exhausts air from within the water level detection chamber 20A into the non-submerged space A2.

The float 30 is formed in an annular shape with a through hole 33 that penetrates in the vertical direction centered on the axis X23. The float guide 23 is inserted through the through hole 33. The outer peripheral surface of the float 30 is a cylindrical surface centered on the axis X23.

The float 30 is, for example, a closed-cell foam made of resin, rubber, soft material, etc., a hollow resin molded product made by blow molding, or a hollow resin molded product made by connecting two parts like a "monaka wrapper," and has a lower specific gravity than the wash water. Although not shown in the figure, a permanent magnet is built into the inside of the float 30.

The float 30 rises and falls in the water level detection chamber 20A in response to the rise and fall of the water level in the water level detection chamber 20A.

As shown by the two-dot chain line in FIG. 6, the upper limit position of the float 30 is the position where the upper surface of the float 30 abuts against the upper limit stopper 29S. Although not shown in the figure, the lower limit position of the float 30 is the position where the lower surface of the float 30 abuts against the lower limit stopper 26S.

The water level sensor 11 is a well-known reed switch arranged on a substrate and is housed in the sensor housing portion 23S of the float guide 23. The signal wiring of the water level sensor 11 is pulled out to the outside through a wiring lead-out hole formed in the cap 29C and connected to the control unit C1.

The water level sensor 11 has internal contacts that are opened and closed in response to the approach and separation of the permanent magnet built into the float 30. The water level detection device 10 uses the float 30 and the water level sensor 11 to detect a specific state in which the water level in the water level detection chamber 20A is at a predetermined water level.

In this embodiment, the specified water level in the water level detection chamber 20A is the water level at which the float 30 rises to the upper limit position shown by the two-dot chain line in Figure 6.

In this embodiment, one end P2A of the drain pipe P2 is located at a position that receives the discharge pressure of the pump 62 when the pump 62 is operating in the normal direction. When the pump 62 is operating in the normal direction, the level of the wash water stored in the water storage space A1 drops by the amount of wash water sprayed from the nozzle 61 into the non-submerged space A2. However, since the discharge pressure of the pump 62 acts on the water level detection chamber 20A, the water level in the water level detection chamber 20A rises above the water level of the wash water stored in the water storage space A1, making it easier for the water level detection device 10 to detect a specific state. For this reason, the control unit C1 needs to determine the water level of the wash water stored in the water storage space A1, taking into account that the discharge pressure of the pump 62 acts on the water level detection chamber 20A.

When the pump 62 is stopped, the discharge pressure of the pump 62 does not act on the water level detection chamber 20A, so the water level in the water level detection chamber 20A accurately reflects the water level of the flushing water stored in the water storage space A1. Therefore, the control unit C1 can directly determine the water level of the flushing water stored in the water storage space A1 from the detection results of the water level detection device 10.

When the pump 62 is operating in reverse, a large amount of wash water discharged outside the dishwasher 1 through the drain pipe P2 flows into the water level detection chamber 20A, causing the water level in the water level detection chamber 20A to rise and the water level detection device 10 to detect a specific state. Then, when the discharge of wash water from the water storage space A1 is nearing completion, the water level in the water level detection chamber 20A drops and the water level detection device 10 no longer detects the specific state. Therefore, the control unit C1 can determine the timing to switch the pump 62 from reverse operation to stop based on the detection result of the water level detection device 10.

<Washing operation>
In the dishwasher 1 having the above-described configuration, when the user operates the input/output unit 40 to instruct the start of the cleaning operation and then pushes the cleaning tub 7 into the storage position, the control unit C1 executes the cleaning operation according to the cleaning operation program shown in Figures 7 to 9.

The cleaning operation includes a cleaning process, a water rinsing process, a heat rinsing process, and a drying process. The water rinsing process is an example of the "rinsing process" of the present invention.

The washing process is a process in which tableware TW1 contained in the washing tank 7 is washed with washing water containing detergent while the heater 63 is operating. The water rinsing process is a process in which tableware TW1 after the washing process is rinsed with unheated clean washing water (washing water not containing detergent) while the heater 63 is not operating.

The heating and rinsing process is a process in which the tableware TW1 after the water rinsing process is rinsed with clean cleaning water while the heater 63 is operating. The drying process is a process in which the tableware TW1 after the heating and rinsing process is dried.

As described below, the control unit C1 is configured to conserve water as much as possible by reducing the amount of water supplied during the rinsing process compared to the amount of water supplied during the cleaning process.

First, in step S101 shown in FIG. 7, the control unit C1 operates the pump 62 in reverse to drain any cleaning water that may remain in the water storage space A1. Then, the control unit C1 proceeds to step S102 and stops the pump 62.

Next, the control unit C1 proceeds to step S111 and starts the cleaning process. In the cleaning process, the control unit C1 activates the heater 63 to heat the cleaning water. The detergent used in the cleaning process is previously placed in a predetermined location in the non-submerged space A2 of the cleaning tank 7 by the user.

Next, the control unit C1 proceeds to step S112, opens the water supply valve 69 to start supplying cleaning water from the water supply pipe P1 to the water storage space A1, and starts measuring the first time T1.

Next, the control unit C1 proceeds to step S113 and determines whether the water level detection device 10 has detected a specific state. At this time, since the pump 62 is stopped, the control unit C1 determines the water level of the flush water stored in the water storage space A1 directly from the detection result of the water level detection device 10.

If the water level in the water level detection chamber 20A is not at the predetermined water level, i.e., the water level at which the float 30 rises to the upper limit position, the water level detection device 10 does not detect a specific state, and the answer in step S113 is "No." Therefore, the control unit C1 determines that the amount of water supplied to the cleaning process has not reached a sufficient amount, and repeats step S113.

When the water level in the water level detection chamber 20A reaches a predetermined level, the water level detection device 10 detects a specific state, and the result in step S113 becomes "Yes." Therefore, the control unit C1 determines that the amount of water supplied to the cleaning process has reached a sufficient amount, and proceeds to step S114.

When the control unit C1 proceeds to step S114, it closes the water supply valve 69 to stop the supply of cleaning water from the water supply pipe P1 to the water storage space A1 and ends the measurement of the first time T1.

In other words, at the start of the cleaning process, the control unit C1 measures the first time T1 from when the water supply valve 69 is opened until the water level detection device 10 detects a specific state in steps S112 to S114.

Next, the control unit C1 proceeds to step S115 and sets a second time T2 that is shorter than the first time T1 based on the first time T1. The control unit C1 then stores the second time T2 in the memory unit C1M.

The second time T2 can be set by using addition, subtraction, multiplication, division, etc. Two specific examples are shown below.
Second time T2=first time T1×α (α is a constant such that 0<α<1)
Second time T2=first time T1-β (β is a constant such that 0<β<first time T1)

The second time T2 is set so as to achieve both a good degree of success in rinsing dirt and detergent from the tableware TW1 during the rinsing process and a good degree of saving on the amount of water supplied during the rinsing process.

Next, the control unit C1 proceeds to step S116 and operates the pump 62 in the forward direction. This causes the nozzle 61 to spray the cleaning water that the pump 62 draws in from the water storage space A1 and pumps out toward the tableware TW1 in the non-submerged space A2, cleaning the tableware TW1.

Next, the control unit C1 proceeds to step S117 and determines whether the required time for the cleaning process has elapsed.

Until the required time for the cleaning process has elapsed, the answer in step S117 will be "No," so the control unit C1 will repeat step S117.

When the required time for the cleaning process has elapsed, step S117 becomes "Yes," and control unit C1 proceeds to step S118.

When the control unit C1 proceeds to step S118, it operates the pump 62 in reverse. As a result, the cleaning water sucked in from the water storage space A1 by the pump 62 and pumped out is discharged outside the dishwasher 1 via the drain pipe P2.

Next, the control unit C1 proceeds to step S119, stops the pump 62, and ends the cleaning process.

Next, the control unit C1 proceeds to step S121 and starts the water rinsing process. Note that the control unit C1 does not operate the heater 63 during the water rinsing process.

Next, the control unit C1 proceeds to step S122 and opens the water supply valve 69 to start supplying cleaning water from the water supply pipe P1 to the water storage space A1.

Next, the control unit C1 proceeds to step S123 shown in FIG. 8 and determines whether the water level detection device 10 has detected a specific state. At this time, since the pump 62 is stopped, the control unit C1 determines the water level of the flush water stored in the water storage space A1 directly from the detection result of the water level detection device 10.

If the water level detection device 10 detects a specific state, the result in step S123 becomes "Yes." Therefore, the control unit C1 determines that the amount of water supplied in the rinsing process is greater than the amount intended for water saving and has reached the same amount as the amount of water supplied in the washing process, and proceeds to step S125 before the amount of water supplied becomes excessive.

On the other hand, if the water level detection device 10 does not detect the specific state, the result in step S123 is "No." Therefore, the control unit C1 proceeds to step S124 and determines whether the second time T2 has elapsed since the water supply valve 69 was opened.

If the second time T2 has not elapsed since the water supply valve 69 was opened, the answer in step S124 is "No," and the control unit C1 repeats steps S123 and S124.

When the second time T2 has elapsed since the water supply valve 69 was opened, the result in step S124 becomes "Yes," so the control unit C1 determines that the amount of water supplied in the water rinsing process has reached the amount of water intended for water saving, and proceeds to step S125.

When the process moves from step S123 or step S124 to step S125, the control unit C1 closes the water supply valve 69 to stop the supply of cleaning water from the water supply pipe P1 to the water storage space A1.

Next, the control unit C1 proceeds to step S126 and operates the pump 62 in the forward direction. This causes the nozzle 61 to spray unheated clean cleaning water, which is sucked in and pumped by the pump 62 from the water storage space A1, toward the tableware TW1 in the non-submerged space A2, rinsing the tableware TW1.

Next, the control unit C1 proceeds to step S127 and determines whether or not the third time T3 has elapsed since the pump 62 started to operate in the normal direction. Here, the third time T3 is an initial setting value stored in advance in the memory unit C1M, and is set to 10 seconds as an example in this embodiment. Note that the third time T3 can be changed as appropriate as long as it is the timing at which the pump 62 starts to operate in the normal direction and the discharge pressure of the pump 62 acts on the water level detection chamber 20A.

If the third time T3 has not elapsed since the pump 62 started rotating in the normal direction, the answer in step S127 is "No," and the control unit C1 repeats step S127.

When the third time T3 has elapsed since the pump 62 started rotating in the normal direction, step S127 becomes "Yes," and the control unit C1 proceeds to step S128.

When the control unit C1 proceeds to step S128, it determines whether the water level detection device 10 has detected a specific state. At this time, since the pump 62 is operating in the normal direction, the control unit C1 determines the water level of the flush water stored in the water storage space A1 based on the detection result of the water level detection device 10, taking into account that the discharge pressure of the pump 62 acts on the water level detection chamber 20A.

If the water level detection device 10 detects a specific state, the result in step S128 becomes "Yes." Therefore, the control unit C1 determines that it was correct to determine that the amount of water supplied in the water rinsing process had reached the amount intended for water saving when the result in step S124 became "Yes," and proceeds to step S137.

On the other hand, if the water level detection device 10 does not detect the specific state, the result in step S128 is "No." Therefore, the control unit C1 determines that it was incorrect to determine that the amount of water supplied in the water rinsing process had reached the amount intended for water saving when the result in step S124 was "Yes," and proceeds to step S131.

When the control unit C1 proceeds to step S131, it stops the pump 62, which was operating in the forward direction.

Next, the control unit C1 proceeds to step S132 and opens the water supply valve 69 to start supplying cleaning water from the water supply pipe P1 to the water storage space A1.

Next, the control unit C1 proceeds to step S133 and determines whether the water level detection device 10 has detected a specific state. At this time, since the pump 62 is stopped, the control unit C1 determines the water level of the flush water stored in the water storage space A1 directly from the detection result of the water level detection device 10.

If the water level detection device 10 does not detect the specific state, the result in step S133 is "No." Therefore, the control unit C1 determines that the amount of water supplied in the rinsing process has not reached the same amount as the amount of water supplied in the cleaning process, and repeats step S133.

When the water level detection device 10 detects a specific state, the result in step S133 becomes "Yes." Therefore, the control unit C1 determines that the amount of water supplied in the rinsing process has reached the same amount as the amount of water supplied in the cleaning process, and the process proceeds to step S134.

When the control unit C1 proceeds to step S134, it closes the water supply valve 69 to stop the supply of cleaning water from the water supply pipe P1 to the water storage space A1.

Next, the control unit C1 proceeds to step S135 and operates the pump 62 in the normal direction. This causes the nozzle 61 to resume spraying cleaning water to rinse the tableware TW1. The control unit C1 then proceeds to step S137.

When the process proceeds from step S128 or step S135 to step S137, the control unit C1 determines whether the required time for the water rinsing process has elapsed.

Until the required time for the water rinsing process has elapsed, step S137 will be "No," so the control unit C1 will repeat step S137.

When the required time for the water rinsing process has elapsed, step S137 becomes "Yes," and the control unit C1 proceeds to step S138.

When the control unit C1 proceeds to step S138, it operates the pump 62 in reverse. As a result, the cleaning water that is sucked in from the water storage space A1 by the pump 62 and pumped out is discharged outside the dishwasher 1 via the drain pipe P2.

Next, the control unit C1 proceeds to step S139, stops the pump 62, and ends the water rinsing process.

Next, the control unit C1 proceeds to step S141 shown in FIG. 9 and starts the heating and rinsing process. In the heating and rinsing process, the control unit C1 activates the heater 63 to heat the cleaning water.

Next, the control unit C1 proceeds to step S142 and opens the water supply valve 69 to start supplying cleaning water from the water supply pipe P1 to the water storage space A1.

Next, the control unit C1 proceeds to step S143 and determines whether the water level detection device 10 has detected a specific state. At this time, since the pump 62 is stopped, the control unit C1 determines the water level of the flush water stored in the water storage space A1 directly from the detection result of the water level detection device 10.

If the water level detection device 10 does not detect the specific state, the result in step S143 is "No." Therefore, the control unit C1 determines that the amount of water supplied to the heating and rinsing process has not reached a sufficient amount, similar to the amount of water supplied to the cleaning process, and repeats step S143.

When the water level detection device 10 detects a specific state, the result in step S143 becomes "Yes." Therefore, the control unit C1 determines that the amount of water supplied to the heating and rinsing process has reached a sufficient amount, approximately the same as the amount of water supplied to the cleaning process, and proceeds to step S144.

When the control unit C1 proceeds to step S144, it closes the water supply valve 69 to stop the supply of cleaning water from the water supply pipe P1 to the water storage space A1.

Next, the control unit C1 proceeds to step S145 and operates the pump 62 in the forward direction. This causes the nozzle 61 to spray clean cleaning water that the pump 62 draws in from the water storage space A1 and pumps out toward the tableware TW1 in the non-submerged space A2, rinsing the tableware TW1.

Next, the control unit C1 proceeds to step S146 and determines whether the required time for the heating and rinsing process has elapsed.

Until the required time for the heating and rinsing process has elapsed, the answer in step S146 will be "No," so the control unit C1 will repeat step S146.

When the required time for the heating and rinsing process has elapsed, step S146 becomes "Yes," and control unit C1 proceeds to step S147.

When the control unit C1 proceeds to step S147, it operates the pump 62 in reverse. As a result, the cleaning water drawn in from the water storage space A1 by the pump 62 and pumped out is discharged outside the dishwasher 1 via the drain pipe P2.

Next, the control unit C1 proceeds to step S148, stops the pump 62, and ends the heating and rinsing process.

Next, the control unit C1 proceeds to step S151 and starts the drying process. Note that the control unit C1 activates the heater 63 during the drying process.

Next, the control unit C1 proceeds to step S152 and operates the drying fan 68 to blow air into the water storage space A1 from which the wash water has been discharged and into the non-submerged space A2. The air blown into the water storage space A1 and the non-submerged space A2 is heated to a predetermined temperature range by the heater 63, drying the tableware TW1 after the heating and rinsing process.

Next, the control unit C1 proceeds to step S153 and determines whether the required time for the drying process has elapsed.

Until the required time for the drying process has elapsed, step S153 will return "No", so control unit C1 will repeat step S153.

When the required time for the drying process has elapsed, step S153 becomes "Yes," and control unit C1 proceeds to step S154.

When the control unit C1 proceeds to step S154, it stops the heater 63 and supplies outside air into the cleaning tank 7 with the drying fan 68 until the temperature of the air in the cleaning tank 7 drops to a predetermined end temperature. Thereafter, the control unit C1 stops the drying fan 68 and ends the cleaning operation program.

<Action and effect>
In the dishwasher 1 of the embodiment, the control unit C1 sets a second time T2 that is shorter than the first time T1 based on the first time T1 measured at the start of the cleaning process in steps S112 to S115 of Figure 7, so that the amount of water supplied to the water rinsing process can be reduced with high reliability by the second time T2.

Let us now consider a case in which, instead of the second time T2, a uniformly determined valve open duration is preset during the manufacturing or shipping stage of the dishwasher 1, and the control unit C1 opens the water supply valve 69 at the start of the water rinsing process, and then closes the water supply valve 69 when the valve open duration has elapsed, thereby reducing the amount of water supplied to the water rinsing process.

In this case, the water supply pressure of the water supply source and the length of the water supply pipe vary depending on the installation location of the dishwasher 1, so the amount of water supplied in the rinsing process, which is determined by the duration the valve is open, is also likely to vary depending on the installation location of the dishwasher 1. In this case, the amount of water supplied may be more than expected or less than expected, causing poor rinsing in the rinsing process and making it necessary to repeat the rinsing process, which may make it difficult to achieve water conservation.

In this regard, after the dishwasher 1 of the embodiment is installed, the first time T1 is measured during the washing process each time the washing operation is performed, and the second time T2 is set based on the first time T1. Therefore, the amount of water supplied during the water rinsing process, which is determined by the second time T2 that accurately reflects the conditions of the installation location, is unlikely to be more or less than expected.

Therefore, in the dishwasher 1 of the embodiment, the water level detection chamber 20A is arranged midway through the drain pipe P2 and is connected to the non-submerged space A2 of the washing tub 7 via the communication path P3, so that water saving during the rinsing process can be achieved with high reliability.

In addition, in this dishwasher 1, the control unit C1 saves the amount of water supplied using the first time T1 and the second time T2 during the water rinsing process, not during the heated rinsing process. At the start of the water rinsing process, for example, if the water supply pressure decreases and the second time T2 has elapsed since the water supply valve 69 was opened, there is a rare risk of a malfunction in which the heater 63 is exposed due to an insufficient amount of cleaning water stored in the water storage space A1. Even in this case, the heater 63 is not operating during the water rinsing process, so no malfunction caused by abnormal heating of the heater 63 occurs.

Furthermore, in this dishwasher 1, when the water level detection device 10 detects a specific state before the second time T2 has elapsed since the water supply valve 69 was opened in steps S123 and S124 in FIG. 8 at the start of the water rinsing process, the control unit C1 closes the water supply valve 69 and operates the pump 62 in the normal direction in steps S125 and S126. If the water supply pressure decreases at the start of the washing process due to the use of a faucet or the like connected to a water supply source separately from the water supply valve 69, the measured first time T1 is likely to be long. In this case, if the water supply pressure returns to normal at the start of the water rinsing process, there is a risk that the amount of water supplied will be excessive until the second time T2 set based on such first time T1 has elapsed, and if no measures are taken, there is a risk of problems such as overflowing due to the excessive amount of water supplied. In this regard, in the dishwasher 1, when the water rinsing process starts, if the water level detection device 10 detects a specific state before the second time T2 has elapsed since the water supply valve 69 was opened, the control unit C1 determines that there is a high possibility that the amount of water supplied during the water rinsing process will be excessive, and closes the water supply valve 69. As a result, the dishwasher 1 can suppress problems such as overflow caused by an excessive amount of water supplied.

In addition, in this dishwasher 1, as shown in FIG. 1, one end P2A of the drain pipe P2 is provided at a position that receives the discharge pressure of the pump 62 when the pump 62 operates in the forward direction and the nozzle 61 sprays the cleaning water. Then, at the start of the water rinsing process, if the water level detection device 10 does not detect a specific state when the pump 62 operates and the nozzle 61 starts spraying the cleaning water in steps S126 to S128 of FIG. 8, the control unit C1 stops the pump 62 and reopens the water supply valve 69 in steps S131 and S132. If the water supply pressure decreases at the start of the water rinsing process due to the use of a faucet or the like connected to a water supply source separately from the water supply valve 69, the amount of water supplied from the opening of the water supply valve 69 until the second time T2 has elapsed may be insufficient, and if no measures are taken, there is a risk of problems such as noise caused by air entrapment in the pump 62 due to an insufficient amount of water being supplied. In this regard, in the dishwasher 1, the discharge pressure of the pump 62, which operates at the start of the rinsing process, acts on one end P2A of the drain pipe P2, causing the water level in the water level detection chamber 20A to rise. If the water level detection device 10 does not detect a specific state when the pump 62 operates and the nozzle 61 begins spraying cleaning water at the start of the rinsing process, the control unit C1 determines that there is a high possibility that the pump 62 will continue to operate with an insufficient amount of water supplied during the rinsing process, and opens the water supply valve 69. As a result, the dishwasher 1 can suppress problems such as noise from the pump 62 caused by an insufficient amount of water supplied.

Furthermore, in this dishwasher 1, the control unit C1 reopens the water supply valve 69 at the start of the water rinsing process in steps S132 to S134 of FIG. 8, and then continues to open the water supply valve 69 until the water level detection device 10 detects a specific state. With this configuration, after opening the water supply valve 69 so that the pump 62 does not continue to operate with an insufficient amount of water supplied in the water rinsing process, the water supply valve 69 continues to be open until the water level detection device 10 detects a specific state, thereby preventing the pump 62 from repeatedly operating and stopping. As a result, this dishwasher 1 can prevent problems such as noise from the pump 62 caused by an insufficient amount of water supplied, and can also prevent the time required for the water rinsing process from becoming longer, thereby improving user comfort.

Although the present invention has been described above with reference to examples, it goes without saying that the present invention is not limited to the above examples and can be modified as appropriate without departing from the spirit of the invention.

In the embodiment, the water rinsing process (steps S121 to S139) shown in Figures 7 and 8 is an example of the "rinsing process" of the present invention, but the present invention is not limited to this configuration. For example, instead of steps S142 to S144 in the heating rinsing process (steps S141 to S148) shown in Figure 9, the heating rinsing process can also be an example of the "rinsing process" of the present invention by performing the same process as steps S122 to S125 shown in Figures 7 and 8 to save water. In this case, in order to suppress problems caused by abnormal heating of the heater 63, it is preferable to set the second time longer than the second time T2 of the water rinsing process in the embodiment.

In the embodiment, after the water supply valve 69 is reopened in steps S132 to S134, the water supply valve 69 continues to be open until the water level detection device 10 detects a specific state, but the present invention is not limited to this configuration. For example, after the water supply valve is reopened, the water supply valve may continue to be open until a preset time (constant value) has elapsed. Also, after the water supply valve is reopened, the water supply valve may continue to be open until a time (variable value) set based on at least one of the first time and the second time has elapsed.

The present invention can be used, for example, in dishwashers or dishwasher-dryers.

1... Dishwasher TW1... Items to be washed (dishes)
7: cleaning tank A1: water storage space A2: non-submerged space 61, 62: cleaning means (61: nozzle, 62: pump)
69...Water supply valve P2...Drainage path (drainage pipe)
20A... Water level detection chamber 10... Water level detection device C1... Control unit T1... First time T2... Second time 63... Heater P2A... One end of the drainage path (one end of the drainage pipe)

Claims (5)

A cleaning tank in which an object to be cleaned is accommodated, the cleaning tank having a water storage space capable of storing cleaning water for cleaning the object to be cleaned, and a non-submerged space located above the water storage space and not storing the cleaning water;
A cleaning means for pumping the cleaning water stored in the water storage space and spraying it toward the object to be cleaned;
a water supply valve for supplying the flush water to the water storage space;
A drainage path for discharging the flush water from the water storage space;
a water level detection device that has a water level detection chamber that is disposed in the drainage path and communicates with the non-submerged space, and detects a specific state in which the water level in the water level detection chamber is at a predetermined water level;
A control unit that controls the washing means and the water supply valve to perform a washing operation for washing the object to be washed, and the control unit acquires a detection result of the water level detection device,
The cleaning operation includes a cleaning step of cleaning the object contained in the cleaning tank with the cleaning water;
A rinsing step of rinsing the object to be cleaned with the cleaning water after the cleaning step,
The control unit is
At the start of the cleaning process, a first time from when the water supply valve is opened to when the water level detection device detects the specific state is measured, and a second time shorter than the first time is set based on the first time;
At the start of the rinsing step, when the second time has elapsed since the water supply valve was opened, the water supply valve is closed to operate the cleaning means ;
The control unit is configured to close the water supply valve and operate the cleaning means when the water level detection device detects the specific state before the second time has elapsed since the water supply valve was opened at the start of the rinsing process . The cleaning means includes a pump that draws in and discharges the cleaning water stored in the water storage space;
a nozzle for spraying the cleaning water discharged by the pump toward the object to be cleaned in the non-submerged space,
one end of the drainage path is provided at a position receiving a discharge pressure of the pump when the pump is operated and the nozzle sprays the cleaning water,
The dishwasher of claim 1, wherein the control unit stops the pump and reopens the water supply valve when the water level detection device does not detect the specific state when the pump is operated and the nozzle begins spraying the cleaning water at the start of the rinsing process. A cleaning tank in which an object to be cleaned is accommodated, the cleaning tank having a water storage space capable of storing cleaning water for cleaning the object to be cleaned, and a non-submerged space located above the water storage space and not storing the cleaning water;
A cleaning means for pumping the cleaning water stored in the water storage space and spraying it toward the object to be cleaned;
a water supply valve for supplying the flush water to the water storage space;
A drainage path for discharging the flush water from the water storage space;
a water level detection device that has a water level detection chamber that is disposed in the drainage path and communicates with the non-submerged space, and detects a specific state in which the water level in the water level detection chamber is at a predetermined water level;
A control unit that controls the washing means and the water supply valve to perform a washing operation for washing the object to be washed, and the control unit acquires a detection result of the water level detection device,
The cleaning operation includes a cleaning step of cleaning the object contained in the cleaning tank with the cleaning water;
A rinsing step of rinsing the object to be cleaned with the cleaning water after the cleaning step,
The control unit is
At the start of the cleaning process, a first time from when the water supply valve is opened to when the water level detection device detects the specific state is measured, and a second time shorter than the first time is set based on the first time;
At the start of the rinsing step, when the second time has elapsed since the water supply valve was opened, the water supply valve is closed to operate the cleaning means;
The cleaning means includes a pump that draws in and discharges the cleaning water stored in the water storage space;
a nozzle for spraying the cleaning water discharged by the pump toward the object to be cleaned in the non-submerged space,
one end of the drainage path is provided at a position receiving a discharge pressure of the pump when the pump is operated and the nozzle sprays the cleaning water,
The control unit of this dishwasher is characterized in that, at the start of the rinsing process, if the water level detection device does not detect the specific state when the pump is operating and the nozzle begins spraying the cleaning water, the control unit stops the pump and reopens the water supply valve. 4. The dishwasher according to claim 2 , wherein the control unit opens the water supply valve again at the start of the rinsing process and then continues to open the water supply valve until the water level detection device detects the specific state. The cleaning water supply system further includes a heater located in the water storage space for heating the cleaning water during the cleaning process.
5. The dishwasher according to claim 1, wherein the rinsing step is a water rinsing step in which the objects to be washed after the washing step are rinsed with unheated washing water while the heater is not in operation.

Images