JP2008093047A - Dishwasher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect a tightly closed state between a washing tub and a lid for tightly closing its opening part by devising how to apply a pressure to the washing tub. <P>SOLUTION: This dishwasher includes: the washing tub having the opening part and storing tableware; the lid for tightly closing the opening part of the washing tub; a washing pump for pumping wash water to a rotating nozzle provided in the washing tub; a drying fan for sending air to the washing tub; an exhaust passage for communicating from the washing tub to the outside of the machine; a water feed solenoid valve for feeding water to the washing tub; a pressure sensor for detecting the pressure in the washing tub on the premise that the dishwasher has a level switch for detecting the water level inside the washing tub; and a tightly closed state detecting means for detecting the tightly closed state of the lid based on the pressure detected by the pressure sensor. The drying fan sends air to the washing tub to increase the pressure inside the washing tub and detect the tightly closed state of the lid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a dishwasher that performs various processes such as washing, rinsing, and drying of tableware and cooking utensils (hereinafter referred to as tableware), and in particular, detecting the sealed state of a lid that seals the opening of a washing tank. It is related with the dishwasher which can do.

The dishwasher is provided with a washing tub for storing dishes inside and washing, rinsing, drying and the like. This washing tank is provided with an opening for taking in and out dishes, so that when washing, rinsing or drying the dishes, the washing water and air should not leak from the opening of the washing tank. The opening is sealed with a lid with a seal. When the sealing state of the opening by the lid is insufficient, washing water or air leaks from the washing tank, which causes water leakage or poor drying.
If the opening of the cleaning tank is sealed with a lid, water leakage or air leakage will occur even if either the positional relationship between the cleaning tank and the lid or the sealing function of the seal itself is defective. Therefore, it is important to comprehensively detect the sealed state.

  Conventionally, in a drawer type dishwasher, a magnet is provided in the inner lid, and a reed switch is provided in a position opposite to the magnet of the inner lid in the washing tank, and the washing tank is accommodated inside the main body of the dishwasher. However, only when the reed switch detects that the inner lid is engaged with the upper opening of the washing tank, it is possible to operate the dishwasher and prevent the occurrence of water leakage. It is disclosed in the gazette ("Dishwasher", Patent Document 1).

Similarly, in the drawer-type dishwasher, if the sealing state of the washing tank is detected and the sealing property is not secured, the operation is stopped to prevent the occurrence of water leakage. ("Dishwasher", Patent Document 2).
As shown in FIG. 6, the dishwasher (dishwasher) 10 described in Patent Document 2 is provided with a washing tub 4 inside a dishwasher main body (outer case) 11. The dishes contained in 14 are washed and dried. The washing tub 4 has a box shape with an opening at the top and is provided with a door 13 on the front surface. The washing tub 4 can be pulled out of the dishwasher main body 11 and put in and out dishes from the upper opening.

An inner lid (upper lid) 6 that closes the upper opening of the washing tub 4 is provided inside the dishwasher body 11. The inner lid 6 is provided with a seal 12, and the movement range is restricted by a guide (not shown). When the cleaning tank 4 is pulled out from the main body 11, the inner lid 6 moves forward and obliquely upward (upward left in FIG. 6) with respect to the cleaning tank 4, remains inside the main body 11 and stops there. When the cleaning tank 4 is pushed into the main body 11 as shown in FIG. 6, the inner lid 6 moves rearward and obliquely downward (downward right in FIG. 6) with respect to the cleaning tank 4, The receiving surface around the upper opening of the cleaning tank 4 abuts via the seal 12 to close the upper opening of the cleaning tank 4. A pressure sensor 7 is provided in the center of the lower surface of the inner lid 6, and measures the internal pressure of the cleaning tank 4 and transmits it to the control device (controller) 30.
As an opening / closing mechanism of the inner lid in the conventional drawer type dishwasher, for example, the inner lid is supported on the dishwasher body by a link mechanism and a spring to open / close the inner lid in accordance with the removal / removal of the washing tub ( (Refer to Patent Document 1), and the inner lid is supported by a vertical guide mechanism and a spring so as to be movable up and down with respect to the dishwasher main body, and the cam mechanism is moved back and forth in accordance with the insertion and removal of the washing tub. Some open / close the lid (see Japanese Patent No. 3789775). In such an inner lid opening / closing mechanism, when the washing tub is pushed into the dishwasher body and its upper opening is closed by the inner lid, the inner lid is to be sealed against the washing tub. It is pressed with a predetermined pressing force.

A temperature sensor 26, a heater 25, and a rotating nozzle (jet nozzle) 15 are provided at the bottom of the cleaning tank 4. The washing water at the bottom of the washing tank 4 can be heated by the heater 25, and the temperature of the washing water is measured by the temperature sensor 26 and is feedback-controlled by the control device 30 so as to reach a predetermined temperature. The heater 25 can also heat the air sent into the cleaning tank 4 by the drying fan 5. The rotary nozzle 15 is rotatably attached and injects wash water pumped from the wash pump 18 toward the dishes stored in the dish basket 14.
A water supply pipe (water supply path) 16 including a water supply electromagnetic valve (water supply electromagnetic valve) 17 is connected to the cleaning tank 4. The controller 30 controls the water supply electromagnetic valve 17 to be opened and closed, and the inside of the cleaning tank 4. Wash water can be supplied. Further, the cleaning tank 4 is provided with a water level detector (water level switch) 24, and outputs a signal to the control device 30 when the cleaning water level reaches a specified water level.

A drainage pipe (drainage channel) 21 and a minimum water level switch 20 are provided at the lowest position of the bottom of the washing tank 4, and the washing water in the washing tank 4 is passed through the drain trap 23 to the drainage pipe 21. A drainage pump 22 is provided for discharging to the outside. The minimum water level switch 20 is a pressure type water level switch for monitoring the water level, and outputs a signal to the control device 30 when the water level in the cleaning tank 4 reaches a specified minimum water level.
A drying fan 5 is provided behind the cleaning tank 4, and can be driven by a command from the control device 30 to send air into the cleaning tank 4. The air sent into the washing tub 4 is heated by the heater 25 to become high-temperature air to dry the dishes, and then passes through the exhaust passage 27 and the flapper (open / close valve) 8 from the exhaust port 28 to the outside of the machine. Discharged.

  The dishwasher 10 configured as described above receives signals from the water level detector 24, the temperature sensor 26, and the like by the control device 30, and also includes a water supply electromagnetic valve 17, a cleaning pump 18, a drainage pump 22, and a drying fan 5. And by controlling the heater 25, the drainage process, the cleaning process, the three rinsing processes, the high temperature rinsing process, and the drying process are automatically executed to clean and dry the dishes. In each of the above processes except the drying process, the drainage pump 22 is driven to suck water from the inside of the washing tank 4 and discharge it outside the apparatus, but the inside of the washing tank 4 is depressurized by the suction by the drainage pump 22. Negative pressure.

FIG. 7 is a graph showing the temporal change in air pressure inside the cleaning tank 4. When the drainage pump 22 of the dishwasher 10 is driven at time t ₀ and the water stored in the washing tub 4 is drained, the inner lid 6 firmly closes the upper opening of the washing tub 4. If the airtightness is ensured, the pressure in the cleaning tank 4 is reduced by the drainage pump 22 and falls along the pressure history 44 from the pressure 41 at the start of operation. On the other hand, if the inner lid 6 does not tightly close the upper opening of the cleaning tank 4 and the sealing property is not secured, the pressure in the cleaning tank 4 is reduced by the drainage pump 22, but the inner lid 6 Since air flows in from the space between the cleaning tanks 4, the pressure reduction by the drain pump 22 is relaxed, and the pressure falls along the pressure history 45 higher than the pressure history 44.

Such a change in the pressure in the cleaning tank 4 is measured, for example, by measuring the pressure in the cleaning tank 4 at a time t ₁ when a predetermined time (for example, 30 seconds) has elapsed from the driving start time t ₀ of the drain pump 22. It can be known by taking the differential pressure from the atmospheric pressure 40. ΔP _{2 in} FIG. 7 represents the relationship between the pressure 42 and the atmospheric pressure 40 at time t ₁ when 30 seconds have elapsed since the drain pump 22 was driven in a state where the upper opening of the cleaning tank 4 is sealed. Indicates differential pressure. ΔP ₁ is the difference between the pressure 43 and the atmospheric pressure 40 at time t ₁ when 30 seconds have elapsed since the drainage pump 22 was driven in a state where the upper opening of the cleaning tank 4 is not sealed. Show. By comparing the absolute value of the differential pressure with a predetermined threshold value, it is possible to detect the sealed state of the upper opening of the cleaning tank 4.

Next, the operation | movement which test | inspects the sealing state of the inner cover 6 of the dishwasher 10 is demonstrated, referring FIG.
When the operation for inspecting the sealed state is started (step 31), the drainage pump 22 is driven to start the drainage of the water stored at the bottom of the cleaning tank 4 (step 32). Next, it is determined whether or not the minimum water level switch 20 is turned off (step 33). If the minimum water level switch 20 is not turned off, it is determined that drainage has not been completed and the routine proceeds to step 34, where it is determined whether or not 3 minutes have elapsed since the drainage started. If 3 minutes have not elapsed, the process returns to step 32 to continue draining. When 3 minutes elapse without draining, the process proceeds to step 35, the drainage abnormality is notified to the user, and the operation of the dishwasher 10 is stopped.

If the lowest water level switch 20 is turned off in step S33, the process proceeds to step 36, and drainage is continued until 30 seconds have elapsed since the lowest water level switch 20 was turned off. When 30 seconds elapse in step 36, the pressure in the cleaning tank 4 is measured by the pressure sensor 7 (step 37), the drainage pump 22 is stopped to stop draining (step 38), and then the process proceeds to step 39.
In step 39, a differential pressure is calculated from the pressure in the cleaning tank 4 measured in step 37, and it is determined whether or not the absolute value of this differential pressure exceeds a threshold value. If the absolute value of the differential pressure exceeds the threshold value, it is determined that the upper opening of the cleaning tank 4 is well sealed by the inner lid 6, and the routine proceeds to step 41 where cleaning, rinsing, and high temperature rinsing are performed as usual. And each step of drying. If the absolute value of the differential pressure does not exceed the threshold value, it is determined that the upper opening of the washing tub 4 is not sealed, and the user is notified of the sealing abnormality and the dishwasher 10 is operated. Stop (step 40).

Further, in Patent Document 2, when the drainage pump 22 is driven and the drainage operation is performed and the minimum water level switch 20 is turned off (see step 33 in FIG. 8), the drainage is stopped and the drying fan is stopped. The pressure in the cleaning tank 4 is reduced by rotating the motor 5 in the reverse direction, and the sealed state of the inner lid 6 of the cleaning tank 4 is determined depending on whether or not the pressure in the cleaning tank 4 becomes a specified pressure or less within a predetermined time. It also describes how to detect.
JP 2000-139798 A JP 2006-51116 A

  In the dishwasher described in the above-mentioned Patent Document 1, only the mutual positional relationship between the location where the magnet of the inner lid is provided and the location where the reed switch of the washing tank is provided is confirmed. Since the other locations and the overall positional relationship and the state of the seal itself have not been confirmed, it is accurate whether the upper opening of the cleaning tank and the inner lid are in a sealed state with no water leakage. Could not be detected.

In the dishwasher described in Patent Document 2 (see FIG. 6), the washing tub 4 communicates with the interior of the dishwasher main body 11 via the drying fan 5 and is not completely sealed, but also drained. The amount of water drained by the pump 22 is small, and the drain pump 22 is in a state of sucking air (air biting state) and cannot always drain well. For this reason, even if the water in the cleaning tank 4 is discharged by the drain pump 22, the pressure in the cleaning tank 4 is not reduced as planned, and the sealed state of the inner lid 6 cannot always be detected accurately.
In addition, after draining with the drain pump 22, the flapper 8 in the exhaust passage 27 is also cleaned when the sealing state of the inner lid 6 is inspected by reversely rotating the drying fan 5 to reduce the pressure in the cleaning tank 4. Since the tank 4 cannot be reliably sealed from the outside air, the pressure in the cleaning tank 4 is not necessarily reduced well as in the case where the pressure is reduced by the drainage of the drainage pump 22 described above, and the sealed state of the inner lid 6 is maintained. It could not always be detected accurately.
Further, in the dishwasher 10 described in the above-mentioned Patent Document 2, since the inside of the inner lid 6 is inspected by depressurizing the inside of the washing tub 4, the seal 12 is slightly opened from the receiving surface around the washing tub 4. Even in a case where it is displaced or slightly lifted up (slight sealing failure), the seal 12 is adsorbed on the receiving surface of the cleaning tank 4 by the negative pressure formed in the cleaning tank 4, and is temporarily good. In some cases, the sealed state is automatically corrected, and the sealed state of the inner lid 6 may not be detected accurately.

  Therefore, in order to solve such problems, the present invention relates to how to apply pressure to the cleaning tank so that the sealing state of the cleaning tank and the lid that seals the opening can be accurately detected. It is to devise.

The dishwasher according to the present invention is based on detecting airtightness of the lid of the washing tub by sending air into the washing tub with a drying fan, increasing the pressure in the washing tub, and the magnitude of the pressure. Is.
(1) A dishwasher according to the present invention (corresponding to claim 1) is provided with an opening, a washing tank for storing dishes, a lid for sealing the opening of the washing tank, and the washing tank. A cleaning pump for pumping cleaning water to the rotating nozzle, a drying fan for sending air to the cleaning tank, an exhaust passage communicating from the cleaning tank to the outside of the machine, a solenoid valve for supplying water to the cleaning tank, and the cleaning Assuming a dishwasher with a water level detector that detects the water level in the tank,
A pressure sensor for detecting the pressure in the cleaning tank;
Based on the pressure detected by the pressure sensor, comprising a sealed state detection means for detecting the sealed state of the lid,
The air is fed into the cleaning tank by the drying fan, and the pressure in the cleaning tank is increased to detect the sealed state of the lid.

With such a configuration, the pressure in the cleaning tank can be increased by driving the drying fan to send air into the cleaning tank. The lid for sealing the opening of the cleaning tank is pressed against the cleaning tank by a predetermined pressing force when the opening is closed regardless of a built-in type such as a drawer type or a desktop type. At this time, if the lid is in a predetermined positional relationship with respect to the cleaning tank, and the seal provided on the lid exhibits its sealing function, the sealed state of the lid with respect to the cleaning tank is secured. The air sent from the fan does not leak to the outside, and the pressure in the cleaning tank rises according to the capacity of the drying fan. On the other hand, if the position of the lid with respect to the cleaning tank is shifted or the seal itself cannot function due to the lift of the seal and the sealing state of the lid is not secured, air leaks from between the cleaning tank and the lid to the outside. The pressure in the washing tank does not increase so much. Therefore, the sealed state of the lid can be detected by driving the drying fan to send air into the cleaning tank and measuring the pressure in the cleaning tank with a pressure sensor.
In this way, when inspecting the sealing state of the lid with respect to the cleaning tank, since the pressure in the cleaning tank is increased, a force for pulling off the lid is applied by the pressure in the cleaning tank, and the air from the cleaning tank And water leaks easily. Under these circumstances, the lid sealing state is detected by measuring the pressure in the washing tank, so that the lid sealing state is reliably detected without giving an erroneous test result. be able to.

(2) Further, in the dishwasher, an exhaust solenoid valve is provided in the exhaust passage, and when the air is fed into the washing tank by the drying fan, the exhaust passage can be closed. (Corresponding to claim 2)
According to this configuration, when the air is fed into the cleaning tank by the drying fan and the lid is inspected for sealing, the exhaust tank is closed by the exhaust solenoid valve and the cleaning tank is sealed. It can be held high, and the sealed state of the lid can be detected more reliably. The pressure in the cleaning tank in this case is, for example, if it is ensured sealed state of the lid, a 12~15mmH ₂ O, unless sealed state is ensured a 5~10mmH ₂ O.
In addition, since the exhaust passage is closed by the exhaust solenoid valve, the odor in the cleaning tank does not leak outside the apparatus during the inspection of the sealed state of the lid.

(3) In the dishwasher, a venturi can be provided in the exhaust passage. (Corresponding to claim 3)
According to this configuration, the pressure in the cleaning tank cannot be kept higher than when an exhaust solenoid valve is provided in the exhaust passage, but the venturi is formed by partially changing the shape of the exhaust passage. Therefore, the manufacturing cost can be reduced.

(4) Further, in the dishwasher, before the washing operation by the washing pump is started, when the water supply solenoid valve is opened and water is supplied to a water level that closes the drain at the bottom of the washing tank, the drying fan Thus, air can be fed into the cleaning tank and the sealed state of the lid can be detected. (Corresponding to claim 4)
According to this configuration, since the sealed state of the lid can be detected before the washing operation by the washing pump is started, the dishwasher can be operated even when the sealed state of the lid with respect to the washing tank is not secured. By stopping, it is possible to prevent water leakage. Also, when water is supplied until the water level closes the drain at the bottom of the washing tank, the lid is inspected for sealing, and the drain pipe can be inspected with water sealed, so the lid can be sealed more accurately. It is possible to detect the state.

(5) Further, in the dishwasher, before the washing operation by the washing pump is started and when the water supply solenoid valve is opened and the water supply to the washing tank is finished, the drying fan supplies the washing tank to the washing tank. Air can be sent in and the sealed state of the lid can be detected. (Corresponding to claim 5)
According to this configuration, similarly to the above (4), even when the sealed state of the lid is not ensured, it is possible to prevent the occurrence of water leakage, and the drain pipe is sealed with water. Since the inspection is performed, the sealed state of the lid can be detected more accurately.
Furthermore, since the inspection of the sealed state of the lid is started when a predetermined amount of water is supplied to the cleaning tank, the drainage at the bottom of the cleaning tank is performed before the sealed state of the lid is inspected as in the case of (4) above. There is no need to supply water until the water level closes.

As described above, according to the dishwasher of the present invention, the pressure in the washing tub applies a force to pull the lid away from the washing tub, and the pressure in the washing tub is measured in a situation where air and water easily leak from the washing tub. Since the lid sealing state is inspected, the lid sealing state can be reliably detected.
When an exhaust solenoid valve is provided in the exhaust passage, the exhaust passage is closed by the exhaust solenoid valve and the cleaning tank is sealed, so that the pressure in the cleaning tank can be kept high. It can be detected more reliably. In addition, odors in the washing tank do not leak outside the machine during the inspection of the sealed state of the lid.
When a venturi is provided in the exhaust passage, the venturi can be formed by partially changing the shape of the exhaust passage, so that the manufacturing cost can be reduced.

Before the washing operation by the washing pump is started, the sealed state of the lid can be detected, so even if the sealed state of the lid is not secured, water leakage occurs by stopping the operation of the dishwasher Can be prevented in advance.
Moreover, since it inspects in the state which sealed the drain pipe of the dishwasher, the sealing state of a lid | cover can be detected more correctly.

  Below, the dishwasher of Example 1 and Example 2 of this invention is demonstrated, referring FIGS. In each embodiment of the present invention, a drawer type dishwasher has been described as an example. However, the present invention is not limited to such a type, and may be a desktop type or a front open type. As long as the cleaning tank has an opening and the opening is sealed with a lid, the invention can be applied to all.

Initially, the dishwasher of Example 1 is demonstrated, referring FIGS. 1-4. Fig. 1 is a schematic diagram of the main part of the dishwasher and a block diagram relating to the control device, Fig. 2 is a flowchart showing the main operation of the dishwasher, and Figs. 3-1 and 3-2 show the sealing state of the lid of the washing tub. FIG. 4 is a graph showing a pressure change in the cleaning tank when the sealed state of the lid is inspected.
In addition, about the structure of the dishwasher of Example 1, since there are many parts in common with the conventional thing shown in FIG. 6, the same code | symbol as FIG. 6 is used for a common part, referring also to FIG. I will explain.

[Dishwasher configuration]
The dishwasher 10a of the first embodiment is based on a conventional general dishwasher, and as schematically shown in FIG. 1 (a), an exhaust passage communicating from the washing tub 4 to the exhaust port 28. 27 is provided with an exhaust electromagnetic valve 1 in place of the flapper in the conventional example and a pressure sensor 3 for measuring the air pressure inside the cleaning tank 4.
More specifically, in the conventional general dishwasher in which the minimum water level switch 20 and the pressure sensor 7 are removed from the dishwasher 10 shown in FIG. 6, instead of the flapper 8 in the exhaust passage 27, An exhaust solenoid valve 1 is provided, and a pressure sensor 3 for measuring the air pressure in the cleaning tank 4 is provided.

As shown in FIG. 1B, the control device 30 provided inside the door 13 of the dishwasher 10a according to the first embodiment configured as described above includes a CPU, a RAM, a ROM, a timer, and the like. The control means 34 which consists of a microcomputer which has, and the load drive circuit 35 which drives various loads are provided.
The control means 34 outputs control signals to the display means 31 and the load drive circuit 35 based on input signals from the various operation keys 32, the water level detector 24, the temperature sensor 26, the pressure sensor 3, and the various sensors 33. . The load driving circuit 35 supplies the load to the cleaning pump 18, the water supply electromagnetic valve 17, the drainage pump 22, the heater 25, the drying fan 5, and the exhaust electromagnetic valve 1 according to a control signal output from the control means 34. By controlling the energization, the cleaning, rinsing and drying processes and the operation of inspecting the sealed state of the inner lid 6 of the cleaning tank 4 are executed.

[Dishwasher operation]
Operation | movement of the dishwasher of Example 1 which has the above structures is demonstrated referring FIGS.
First, main operations for performing the washing process, the rinsing process, and the like in the dishwasher will be described with reference to FIG. After the user turns on the power switch and prepares to store dishes in the table 14, the user selects a desired driving course with the course selection switch (step 1) and turns on the start / pause switch. (Step 2), the operation starts and the cleaning process is started. When the cleaning process is started in this manner, first, the drain pump 22 is driven for a predetermined time (for example, 1 minute) to perform initial drain (steps 3 to 5). Next, the water supply electromagnetic valve 17 is opened (step 6), and after a predetermined amount of water is supplied into the cleaning tank 4, the water supply electromagnetic valve 17 is closed (steps 7 to 8). Subsequently, the cleaning pump 18 is driven to start the cleaning operation (step 9), and the operation is continued according to the selected operation course (step 10). After the rinsing process and the drying process are executed, the operation is ended. .

<Operation to inspect the sealed state of the inner lid>
During the main operation of the dishwasher 10a as described above, an operation for inspecting the sealed state of the inner lid 6 is executed. Such an operation is performed before the first cleaning operation by the cleaning pump 18 is started and before water supply to the cleaning tank 4 is started (location A between step 5 and step 6 in FIG. 2). Or when the water supply to the washing tank 4 is completed (location B between step 8 and step 9 in FIG. 2).
In addition, in the rinsing process, before the first rinsing operation by the cleaning pump 18 is started and before the water supply to the cleaning tank 4 is started, or when the water supply to the cleaning tank 4 is finished It is also possible to execute either of the above.

(Inspection before the start of water supply to the washing tank)
First, the “operation for inspecting the sealed state of the inner lid” executed before water supply to the cleaning tank 4 is started (at the point A in FIG. 2) will be described with reference to FIG. 3-1.
In the main operation of the dishwasher 10a shown in FIG. 2, when the initial drainage is completed and the drainage pump 22 is stopped (step 5), the process proceeds to step 11 of the operation flow shown in FIG. Is opened and water supply to the washing tank 4 is started. When the water level in the washing tank 4 reaches the specified water level (step 12), the water supply electromagnetic valve 17 is closed to stop water supply (step 13). The “specified water level” in this case is a water level that blocks the drain outlet at the bottom of the cleaning tank 4 and does not block the outlet of the drying fan 5. The water level is detected by setting the water level detector and the water supply time. It can be carried out. Next, after closing the exhaust port 28 by closing the exhaust solenoid valve 1 provided in the exhaust passage 27 (step 14), the drying fan 5 is driven to send air into the cleaning tank 4, and the cleaning tank 4 is increased (step 15).
As described above, in the first embodiment, the exhaust port 28 is closed by the exhaust electromagnetic valve 1 provided in the exhaust passage 27, so that even when air is sent into the cleaning tank 4 by the drying fan 5, The odor is not discharged outside the machine.

When a predetermined time (for example, 15 seconds) has elapsed since the start of the driving of the drying fan 5 (step 16), the pressure in the cleaning tank 4 is measured by the pressure sensor 3 (step 17), and then the drying fan 5 The exhaust solenoid valve 1 is opened, and the exhaust port 28 is opened (step 18). The pressure in the cleaning tank 4 measured by the pressure sensor 3 in step 17 is, for example, 12 to 15 mmH ₂ O if the sealed state of the inner lid 6 is normal, but 5 to 5 if the sealed state is abnormal. 10 mm H ₂ O.
The pressure measured in step 17 is compared with a threshold value (step 19). If the measured pressure is equal to or greater than the threshold value, it is determined that the sealed state of the inner lid is normal. End and return to step 6 of FIG. 2 to continue the main operation of the dishwasher. If the measured pressure is not equal to or greater than the threshold value in step 19, it is determined that there is an abnormality in the sealed state of the inner lid, and the occurrence of water leakage is prevented by stopping the operation of the dishwasher ( Step 20).

(Inspection at the end of water supply to the washing tank)
Next, the “operation for inspecting the sealed state of the inner lid” performed when the water supply to the cleaning tank 4 is completed (at the point B in FIG. 2) will be described with reference to FIG. 3-2.
In the main operation of the dishwasher 10a shown in FIG. 2, when the water supply to the washing tub 4 is finished and the water supply electromagnetic valve 17 is closed (step 8), the process proceeds to step 21 of the operation flow shown in FIG. 3-2. The exhaust solenoid valve 1 is closed and the exhaust port 28 is closed. Next, the drying fan 5 is driven to send air into the cleaning tank 4 to increase the pressure in the cleaning tank 4 (step 22). When a predetermined time (for example, 15 seconds) has elapsed since the start of driving of the drying fan 5 (step 23), the pressure sensor 3 measures the pressure in the cleaning tank 4 (step 24), and then the drying fan 5 is stopped. At the same time, the exhaust solenoid valve 1 is opened (step 25). The pressure measured in step 24 is compared with a threshold value (step 26). If the measured pressure is equal to or greater than the threshold value, it is determined that the sealed state of the inner lid 6 is normal, and this operation flow is performed. And return to step 9 in FIG. 2 to continue the main operation of the dishwasher. In step 26 described above, if the measured pressure is not equal to or greater than the threshold value, it is determined that there is an abnormality in the sealed state of the inner lid, and the occurrence of water leakage is prevented by stopping the operation of the dishwasher ( Step 27).

Here, changes in the air pressure in the cleaning tank 4 when the sealed state of the inner lid 6 of the cleaning tank 4 is inspected will be described with reference to FIG. At this time, the inner lid 6 closes the upper opening of the cleaning tank 4 and is pressed against the cleaning tank 4 with a predetermined pressing force. When at time T ₀ is driven drying fan 5 dishwasher 10a air is sent to a started cleaning tank 4, sealability tightly close the inner lid 6 is an upper opening of the washing tub 4 is reserved Then, the pressure in the cleaning tank 4 increases along the pressure history 36 from the pressure P ₀ (atmospheric pressure) at the start of driving. On the other hand, if the inner lid 6 does not tightly close the upper opening of the cleaning tank 4 and the sealing property is not secured, the pressure in the cleaning tank 4 is increased by the drying fan 5, but the inner lid 6 Since air escapes from between the cleaning tank 4 and the washing tank 4, the pressure increase by the drying fan 5 is alleviated and rises along pressure histories 37 and 38 lower than the pressure history 36.

For example, the pressure change in the cleaning tank 4 is measured by measuring the pressure in the cleaning tank 4 at a time T ₁ when a predetermined time (for example, 15 seconds) has elapsed from the driving start time T ₀ of the drying fan 5. Can know by. The pressure history 36 in FIG. 4 is a case where the upper opening of the cleaning tank 4 is sealed, and shows the pressure P ₃₆ at time T ₁ when 15 seconds have elapsed since the drying fan 5 was driven. Moreover, the pressure histories 37 and 38 are the cases where the sealing property of the upper opening of the cleaning tank 4 is not ensured, and indicate the pressures P ₃₇ and P ₃₈ at time T ₁ . By comparing the measured pressures P ₃₆ , P ₃₇ , and P ₃₈ with a predetermined threshold value P _t , the sealed state of the inner lid 6 at the upper opening of the cleaning tank 4 can be detected.

Next, the dishwasher of Example 2 will be described with reference to FIG. FIG. 5 is a schematic diagram of a main part of the dishwasher and a block diagram relating to the control device.
In addition, about the structure of the dishwasher of Example 2, since there are many parts in common with the conventional thing shown in FIG. 6, the same code | symbol as FIG. 6 is used for a common part, referring also to FIG. I will explain.

[Dishwasher configuration]
The dishwasher 10b according to the second embodiment is based on a conventional general dishwasher and, as schematically shown in FIG. 5A, an exhaust passage communicating from the washing tub 4 to the exhaust port 28. 27, the venturi 2 is provided upstream of the flapper 8, and the pressure sensor 3 for measuring the pressure in the cleaning tank 4 is provided in the venturi 2.
More specifically, in the conventional general dishwasher in which the minimum water level switch 20 and the pressure sensor 7 are removed from the dishwasher 10 shown in FIG. 6, the venturi upstream of the flapper 8 in the exhaust passage 27 is provided. 2, and a pressure sensor 3 is provided on the venturi 2.

The control device 30 provided inside the door 13 of the dishwasher 10b according to the second embodiment configured as described above is substantially similar to the case of the first embodiment as shown in FIG. , A control means 34 comprising a microcomputer having a CPU, a RAM, a ROM, a timer, and the like, and a load driving circuit 35 for driving various loads.
The control means 34 outputs control signals to the display means 31 and the load drive circuit 35 based on input signals from the various operation keys 32, the water level detector 24, the temperature sensor 26, the pressure sensor 3, and the various sensors 33. . The load drive circuit 35 controls the energization of the washing pump 18, the water supply electromagnetic valve 17, the drainage pump 22, the heater 25, and the drying fan 5 as loads according to a control signal output from the control means 34. , Cleaning, rinsing, and drying processes, and an operation of inspecting the sealed state of the inner lid 6 of the cleaning tank 4 are executed.

[Dishwasher operation]
Operation | movement of the dishwasher 10b of Example 2 which has the above structures is demonstrated.
Main operations such as the washing process and the rinsing process in the dishwasher are the same as those in the first embodiment shown in FIG.
<Operation to inspect the sealed state of the inner lid>
Further, the operation for inspecting the sealed state of the inner lid is almost the same as that of the first embodiment shown in FIGS. 3-1 to 4, but the dishwasher 10b according to the second embodiment is the same as that of the first embodiment. Since there is a slight difference in configuration as compared with that of Example 1, the difference in operation due to the difference in configuration will be described, and description of most common operations will be omitted.

In the dishwasher 10b of the second embodiment, as shown in FIG. 5A, since the venturi 2 is provided in the exhaust passage 27, the drying fan 5 is driven to feed air into the washing tank 4. When the pressure in the cleaning tank is increased, it is not necessary to close the exhaust solenoid valve 1 and close the exhaust passage 27 as in the case of the first embodiment, and the pressure in the cleaning tank 4 is merely driven by the drying fan 5. It is possible to increase the pressure.
Therefore, it is not necessary to close or open the exhaust port 28 in the operation of inspecting the sealed state of the inner lid. This point will be specifically described based on the operation flow shown in FIG. 3A and FIG. 3B. The operation of “close the exhaust port” in step 14 in FIG. The operation of “opening the exhaust port” is unnecessary, and the operation of “closing the exhaust port” in step 21 and the operation of “opening the exhaust port” in step 25 are unnecessary.
Since the other operations are the same as those in the first embodiment, the operation of the second embodiment can be fully understood from the description of the operation of the first embodiment shown in FIGS.

Thus, in the second embodiment, since the venturi 2 and the flapper 8 are provided in the exhaust passage 27, when the air is sent to the cleaning tank 4 by the drying fan 5 to increase the pressure in the cleaning tank, the cleaning tank 4 is slightly lower than that in the first embodiment, but the venturi 2 can be formed by changing the shape of a part of the exhaust passage 27, so that the exhaust solenoid valve 1 according to the first embodiment using the exhaust solenoid valve 1 is used. Thus, the manufacturing cost can be reduced.
In each of the embodiments of the present invention, the cleaning pump and the drainage pump are shown separately, but an integrated pump (cleaning / drainage pump) that is used for both cleaning and drainage is used. Also good.

These are explanatory drawings of the dishwasher by Example 1 of this invention, (a) is a schematic diagram of the principal part of a dishwasher, (b) is a block diagram regarding the control apparatus of a dishwasher. These are the flowcharts explaining the main operation | movement of the dishwasher by Example 1 similarly. These are the flowcharts explaining the operation | movement which test | inspects the sealing state of an inner cover in the dishwasher by Example 1 similarly. These are another flowchart explaining the operation | movement which test | inspects the sealing state of an inner cover in the dishwasher by Example 1 similarly. These are the graphs explaining the pressure change in a washing tank when inspecting the sealing state of an inner lid | cover similarly in the dishwasher by Example 1. FIG. These are explanatory drawings of the dishwasher by Example 2 of this invention, (a) is a schematic diagram of the principal part of a dishwasher, (b) is a block diagram regarding the control apparatus of a dishwasher. These are typical longitudinal cross-sectional views of the conventional drawer-type dishwasher. These are the graphs which show the pressure change in a washing tank when test | inspecting the sealing state of an inner cover in the conventional dishwasher. These are flowcharts explaining the operation | movement which test | inspects the sealing state of an inner cover in the conventional dishwasher.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Exhaust solenoid valve 2 ... Venturi 3 ... Pressure sensor 4 ... Washing tank 5 ... Drying fan 6 ... Inner lid (of washing tank) 8 ... Flapper 10, 10a, 10b ... Dishwasher 11 ... (Dishwasher) main body 12 ... (inner lid) seal 13 ... Door 15 ... Rotating nozzle 17 ... Water supply solenoid valve 18 ... Washing pump 22 ... Drain pump 24 ... Water level detector 27 ... Exhaust passage 28 ... Exhaust port 30 ... Control device

Claims (5)

A washing tank with an opening and storing tableware;
A lid for sealing the opening of the cleaning tank;
A cleaning pump for pumping cleaning water to a rotating nozzle provided in the cleaning tank;
A drying fan for sending air to the cleaning tank;
An exhaust passage communicating from the washing tank to the outside of the machine;
A water supply solenoid valve for supplying water to the washing tank;
In a dishwasher having a water level detector for detecting the water level in the washing tank,
A pressure sensor for detecting the pressure in the cleaning tank;
Based on the pressure detected by the pressure sensor, comprising a sealed state detection means for detecting the sealed state of the lid,
A dishwasher characterized by detecting the sealed state of the lid by sending air into the washing tank by the drying fan and increasing the pressure in the washing tank.   2. The dishwasher according to claim 1, wherein an exhaust solenoid valve is provided in the exhaust passage, and the exhaust passage is closed when air is fed into the washing tank by the drying fan.   2. The dishwasher according to claim 1, wherein a venturi is provided in the exhaust passage.   Before the cleaning operation by the cleaning pump is started, when the water supply solenoid valve is opened and water is supplied to a water level that closes the drain at the bottom of the cleaning tank, air is sent to the cleaning tank by the drying fan, and the lid The dishwasher according to any one of claims 1 to 3, wherein a hermetic state is detected. Before the cleaning operation by the cleaning pump is started, when the water supply solenoid valve is opened and the water supply to the cleaning tank is completed, air is sent to the cleaning tank by the drying fan, and the lid is closed. The dishwasher according to any one of claims 1 to 3, wherein the dishwasher is detected.

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