JP3524764B2 - Diagnosis device for tank water level detection switch in washing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for diagnosing whether an overflow detection switch provided in a hot water storage tank of a washing machine operates normally.

[0002]

2. Description of the Related Art In a hot water storage tank provided in a dishwasher for storing rinse water (warm water), a rinse valve is set to a preset water level by opening and closing a water valve provided in a hot water supply pipe in response to a detection signal from a float switch. Considering the case where the above-mentioned float switch, water valve, etc. have a failure while storing water, if hot water supply is not stopped even if it exceeds the set water level, warm water that exceeds the overflow water level is supplied from the overflow port. The allowance is made to discharge it to the outside. If the user does not notice the overflow when the above-mentioned overflow occurs, the hot water is continuously discharged and the water and energy for heating the water are wasted. Therefore, the applicant of the present application is
In Japanese Patent Application No. 7-86434 filed earlier, an overflow switch is provided to detect when the water level in the hot water storage tank reaches the overflow port, and an alarm is issued to notify the user when the overflow switch operates. It has been proposed to provide a means for self-diagnosing whether or not the overflow switch operates normally.

The self-diagnosis operation of the overflow switch a will be described below with reference to FIG. Water is supplied by opening the water valve c provided in the hot water supply pipe b, and when the float switch d is turned on when the set water level A is reached as shown in FIG.
Enter into the pass / fail judgment. Therefore, the hot water supply is further forcibly performed, and as shown in FIG. 7B, the overflow switch a is reached after a predetermined time when it is considered that the overflow water level B has been reached.
Whether the ON operation is good or not is determined by whether or not the ON operation is performed. When the overflow switch a is turned on, the hot water supply is stopped, and subsequently the rinse pump e is driven to pump the rinse water under pressure. If the predetermined time has passed since the rinse pump e was started, the water level should have dropped as shown in FIG.
The quality of the off operation is determined by whether or not the overflow switch a is turned off after the elapse of a predetermined time.

[0004]

By the way, since the dishwasher handles dirt, it is common to drain all the washing tanks after the work is completed every day, and therefore when the work is started next time. It is necessary to perform so-called initial hot water supply, in which hot water is newly supplied to the cleaning tank. This initial hot water supply is performed by repeatedly storing hot water once in the hot water storage tank f, then driving the rinsing pump e to eject the hot water into the cleaning chamber by the rinsing nozzle, and collecting the hot water in the cleaning tank. When the cleaning tank is full, detergent is mixed and stored as cleaning water. As described above, it takes a predetermined time for the initial hot water supply, and then the cleaning cycle can be performed. So conventionally,
The self-diagnosis of the overflow switch a described above is shown in FIG.
As shown in (A), the power was turned on to the dishwasher before the initial hot water supply. This is because the self-diagnosis also takes a dedicated time as described above, but it is considered that the user does not feel much inconvenience because it is incorporated as part of the initial hot water supply.

However, it has been found that there is a problem in performing the self-diagnosis of the overflow switch a when the power is turned on. This is the case when the power is turned off due to a momentary power failure after the normal operation after the initial hot water supply is completed, or the power is turned off and turned on again for some reason. For example, if the power is interrupted due to a power failure during the execution of the cleaning cycle, restarting the cleaning cycle from the beginning by pressing the operation switch after turning the power on again is a reliable way to ensure cleaning. Is preferred. However, if the self-diagnosis of the overflow switch a is set at the time of power-on as described above, the self-diagnosis must be performed first and then completed as shown in FIG. 7B. The wash cycle does not start. That is, since the cleaning is not immediately restarted despite pressing the operation switch, the user may mistakenly think that the machine has broken down, and there is a problem that an additional waiting time is added.

As another problem, there is a case where the quality of the off operation of the overflow switch a cannot be accurately determined. For example, when there is no water in the hot water storage tank f or the pipes immediately after installation of the dishwasher or after maintenance, and therefore hot water is supplied to the hot water storage tank f for self-diagnosis of the overflow switch a when the power is turned on. In addition, air may be accumulated in the rinse pump e. Then, as shown in FIG. 6 (B), when the rinse pump e is driven from the state where the overflow water level is B, the water level does not drop to the normal position within a predetermined time due to the above-mentioned air accumulation, and the overflow occurs. The switch a may not be turned off although it is normal. That is, there is a possibility that an erroneous judgment may be made. Especially in cold regions, the water in the pump may be drained every day to prevent freezing, and the above-mentioned misjudgment may occur frequently. The present invention has been completed based on the above circumstances, and an object thereof is to enable diagnosis of a tank water level detection switch accurately and with effective use of time.

[0007]

According to another aspect of the present invention, there is provided a diagnostic device for a tank water level detection switch in a washing machine, comprising: a washing tank; and a hot water storage tank having a constant water supply mechanism capable of storing hot water at a set water level. , have rows initial hot water supply for storing the washing water into the washing tank by repeating several times the step of recovering the cleaning tank ejected by the pump to rinse the hot water stored in the hot water storage tank, and the hot water storage capacitor
After storing the setting of the hot water level in the tank, a cleaning step of recovering the same washing tank and ejected toward the object to be cleaned by washing pump wash water in the wash tank, the hot water of the hot water storage tank wherein It is ejected toward the object to be cleaned by a rinsing pump, collected in the cleaning tank, and heated in the hot water storage tank.
In a washing machine in which a washing cycle consisting of a rinsing step of replenishing water to a set water level is repeatedly executed, the hot water storage tank has an overflow port for overflowing hot water when the set water level is exceeded and a water level for the overflow port. And a detection switch for detecting that the overflow water level has reached, and a device for diagnosing whether or not the detection switch operates normally, forcibly changing the overflow water level in the hot water storage tank. A forced water supply means for raising the temperature to the overflow water level, a judgment means for judging whether or not the detection switch has detected within a predetermined time that the water level has reached the overflow water level, and the forced water supply. Cleaning means after the initial hot water supply
During the cycle and before the start of the next cleaning cycle
The diagnostic execution means for executing the rinsing pump when the rinsing pump is not in operation is provided.

According to another aspect of the present invention, there is provided a diagnostic device for a tank water level detecting switch in a washing machine, comprising: a washing tank; and a hot water storage tank having a fixed amount water supply mechanism capable of storing hot water at a set water level. set the hot water in the initial hot water to have a row, and the hot water storage tank for storing the washing water into the washing tank by repeating several times the step of recovering the cleaning tank and ejected by been rinsed hot water pump
After the water is stored at the water level, a cleaning process in which the cleaning water in the cleaning tank is jetted toward the object to be cleaned by a cleaning pump and is collected in the cleaning tank, and hot water in the hot water storage tank is cleaned by the rinsing pump. Ejected toward an object and collected in the washing tank and warm water in the hot water storage tank up to a set water level
In a washing machine in which a washing cycle consisting of a rinsing step of replenishing is repeatedly executed, the hot water storage tank has an overflow port for overflowing warm water when the set water level is exceeded and an overflow water level at which the water level reaches the overflow water level. A device for diagnosing whether or not the detection switch operates properly, and a forced water supply for forcibly raising the water level in the hot water storage tank to the overflow water level. And means for determining whether or not the detection switch detects that the water level has dropped from the overflow water level within a predetermined time when the rinse pump is started in a state where the water level is at the overflow water level. And a diagnostic execution means for executing the forced water supply means after the middle of the initial hot water supply. Having. The invention of claim 3 is characterized in that, in the invention of claim 2, the diagnosis execution means is adapted to execute the forced water supply means in accordance with the cleaning cycle.

[0009]

<Operation and effect of the invention><Invention of claim 1> After the initial hot water supply is completed , during the cleaning cycle and the next cleaning service.
Rinse pump runs in the time it takes to cycle
When not in diagnostic water forced water supply means by the function executing unit is executed is forcibly performed, the water level will certainly increase because this between you too pump is in a non-driven state, the water level by the determination means It is determined whether or not the detection switch has reached the overflow water level within a predetermined time, and self-diagnosis of the detection switch is performed when the water level rises. In other words, a self-diagnosis of the detection switch, washed
In the cycle and before the start of the next cleaning cycle
To do it when the rinse pump is not running
Therefore , for example, when the restarting operation is performed after the interruption of the cleaning cycle, the cleaning cycle can be immediately restarted and there is no possibility of being mistaken for a failure. In addition, it is not necessary to take extra time for self-diagnosis, and time can be saved.

<Invention of Claim 2> When the initial hot water supply progresses to some extent, the function of the diagnosis execution means executes the forced water supply means to forcibly raise the water level to the overflow water level, and then when the rinse pump is driven. Then, the determination means determines whether or not the detection switch detects that the water level has dropped from the overflow water level within a predetermined time, and self-diagnoses the detection switch when the water level is lowered. That is, the self-diagnosis of the detection switch is performed after the initial hot water supply, during which the rinse pump has already been driven several times and is in a stable state without air traps, etc. Since the decrease can be expected, the detection switch can be accurately diagnosed when the water level is decreased. <Invention of claim 3> The self-diagnosis of the detection switch is performed at the place where the cleaning cycle is performed after the initial hot water supply is completed, and the rinse pump is brought to a more stable state during the initial hot water supply. It is possible to more accurately diagnose the detection switch in time.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG.
Or, it demonstrates based on FIG. First, the structure of the dishwasher will be described with reference to FIG. 1. On the upper side of the main body 1, there is formed a washing chamber 2 in which dishes can be taken in and out via a rack (not shown). The washing chamber 2 has a ceiling side. The cleaning nozzle 3 and the rinsing nozzle 4 are provided in pairs on the bottom side. A cleaning tank 5 for storing cleaning water mixed with detergent is formed on one side of the bottom surface of the cleaning chamber 2, and the cleaning water stored in the cleaning tank 5 is pumped up by a cleaning pump 6 from the cleaning nozzle 3 described above. It is circulated and supplied so that it is jetted toward the tableware and then collected in the cleaning tank 5.

A hot water storage tank 7 for storing rinse water (warm water) is provided below the cleaning tank 5 and is maintained at a set water level by a fixed amount water supply mechanism. In detail, as shown in FIG. 2, a hot water supply pipe 8 drawn from a hot water generator (not shown) is connected to an upper portion of the hot water storage tank 7, and a water valve 9 that can be controlled to open and close is connected to the hot water supply pipe 8. The water level in the hot water storage tank 7 is set to A
A float switch 11 is provided to detect that The opening / closing of the water valve 9 is controlled based on the on / off operation of the float switch 11 so that the inside of the hot water storage tank 7 is maintained at the set water level A. The stored warm water is pumped up by the rinsing pump 12, sprayed from the rinsing nozzle 4 toward the dishes, and collected in the washing tank 5. The washing tank 5 is equipped with an overflow pipe 13 so that the hot water overflowed from the washing tank 5 can be discharged to the outside. In addition, heaters 15 and 16 are provided in the washing tank 5 and the hot water storage tank 7, respectively.
A thermostat (not shown) is installed so that the wash water is kept at about 60 ° C and the rinse water is kept at about 80 ° C.

A normal cleaning cycle is performed in the following manner. When the dishes are stored in the washing room 2 and the washing switch is pressed, the washing process is started. Here, the washing water in the washing tank 5 is pumped up by the washing pump 6 and sprayed from the washing nozzle 3 to wash the dishes. After a predetermined rest time, the rinsing process is started, in which the rinsing water in the hot water storage tank 7 is pumped up by the rinsing pump 12 and sprayed from the rinsing nozzle 4 to perform rinsing. In the meantime, the fixed amount water supply mechanism stores the rinse water in the hot water storage tank 7 up to the set water level A, and waits for the next cleaning cycle.

On the other hand, since the cleaning water in the cleaning tank 5 is mixed with the removed dirt and the like, the cleaning tank 5 is entirely drained at the end of the work every day. Therefore, when the work is started next time, it is necessary to supply hot water to the washing tank 5 again to remake the washing water. This is called initial hot water supply. Here, hot water must be stored in the large-capacity washing tank 5, and since it is difficult to supply a large amount of hot water at once, hot water supply is performed by the following procedure. Done. That is, the hot water generated by the hot water generator is temporarily taken up to the set water level A of the hot water storage tank 7, and then the hot water is pumped up by the rinse pump 12 and jetted from the rinse nozzle 4 to be stored in the cleaning tank 5. This hot water supply cycle is repeated until the cleaning tank 5 is full, and the initial hot water supply is completed.

By the way, in case of a failure of the float switch 11 or the water valve 9 which constitutes the fixed amount water supply mechanism of the hot water storage tank 7, hot water in the hot water storage tank 7 overflows into the hot water storage tank 7 as shown in FIG. An overflow pipe 20 is provided for this purpose. The upper end opening 20A of the overflow pipe 20 is located above the set water level A by a predetermined dimension, and when the water level in the hot water storage tank 7 exceeds an overflow water level B higher than the set water level A, it is exceeded. The warm water for a minute is drained to the outside.
Along with this, the hot water storage tank 7 is provided with a float type overflow switch 21 for detecting that the water level in the hot water storage tank 7 has reached the overflow water level B. The overflow switch 21 detects that the water level in the hot water storage tank 7 has reached the overflow water level B, and issues an alarm or the like to promptly inform the user that an overflow has occurred.

In the present embodiment, a diagnostic process for self-diagnosing whether or not the overflow switch 21 described above operates normally is performed. Therefore, a control device is provided, and the following control is executed by its software configuration. The diagnostic process will be described with reference to the flowchart of FIG. 3 and FIG. This embodiment is also characterized by the timing of execution of the diagnostic process, and the diagnostic process is executed at the start of the first cleaning cycle after the power switch is turned on. That is, when the power switch is turned on, first in step S1,
It is determined whether the first wash cycle has started. As described above, the initial hot water supply is performed when the power is turned on, but the diagnostic process is not executed during the initial hot water supply. After the completion of the initial hot water supply, the first cleaning cycle is started by turning on the operation switch or the like (step S1 indicates “YE
S ”), and the following diagnostic process is executed with it.
After the power switch is turned on, a flag is set when the first cleaning cycle is executed, and the diagnostic process is not executed in the subsequent cleaning cycles.

When the first wash cycle begins,
As shown in FIG. 4 (A), the hot water storage tank 7 stands by in a state where the rinse water is stored at the set water level A. When the diagnosis process is executed, the water valve 9 is turned on in step S2, and hot water is forcibly supplied to the hot water storage tank 7. As a result, the water level in the hot water storage tank 7 gradually rises and eventually reaches the overflow water level B as shown in FIG. 4 (B). At this time, since the washing process is performed on the dishwasher side and the rinse pump 12 is in the non-driving state, the water level in the hot water storage tank 7 rises smoothly. Therefore, next, in step S3, it is determined whether the overflow switch 21 is turned on within the first set time after the water valve 9 is turned on. The first set time is required to be long enough to reach the overflow water level B from the set water level A. If the overflow switch 21 is not turned on even after the lapse of the first set time (“NO” in step S3), the overflow switch 21 is not turned on even though the overflow water level B is reached. Two
It is determined that the ON operation of No. 1 is abnormal. In this case, the water valve 9 is turned off in step S4, and then an alarm is issued by a buzzer or a display unit in step S5. As a result, the user can easily know that the overflow switch 21 has an abnormality, and the machine is stopped by turning off the power switch (step S6).

On the other hand, in step S3, the overflow switch 21 is turned on within the first set time and "YE
When it becomes "S", it is diagnosed that the overflow switch 21 is normally turned on, and in step S7,
The water valve 9 is turned off. Then, next, it is diagnosed whether or not the overflow switch 21 is normally turned off. That is, when the rinsing process is moved to the rinsing process in the rinsing cycle, in the next step S8, the rinsing pump 12 is turned on, whereby the rinsing water in the hot water storage tank 7 is pumped and the water level is gradually lowered. Four
As in (C), the water level C below the overflow water level B should be reached. Therefore, next, in step S9, it is determined whether or not the overflow switch 21 is turned off within the second set time after the rinse pump 12 is activated. The second set time is required to be long enough for the water level to surely fall below the overflow water level B. Then, even if the second set time elapses, the overflow switch 2
If 1 is not turned off ("N" in step S9
O "), it is determined that the overflow switch 21 does not operate normally. In this case, the rinsing pump 12 is turned off in step S10, and then an alarm is issued by the buzzer or the display from step S5. Thus, the user can easily know that the overflow switch 21 is abnormal, and the machine is stopped by turning off the power switch (step S6).
In step S9, when the overflow switch 21 is turned off within the second set time and becomes "YES", it is diagnosed that the overflow switch 21 is normally turned on, and the rinse pump 12 is determined in step S11 at the end of the rinsing process. Is turned off, and normal operation is continued.

In this embodiment, as shown in FIG. 5A, the self-diagnosis of the overflow switch 21 is executed at the start of the first cleaning cycle after the power is turned on. Can be obtained. First, in order to perform a diagnostic process, particularly to judge whether the ON operation of the overflow switch 21 is good or bad, it takes time to forcibly raise the water level from the set water level A to the overflow water level B, as shown in FIG. 4 (B). Since this forced water supply can be performed during the cleaning process in the cleaning cycle, no extra time is needed for the diagnostic process.

Further, in this type of dishwasher, if the power is interrupted due to the power being cut off during the execution of the cleaning cycle, the power is turned off and then the operation switch is pressed to start the cleaning cycle first. Are programmed to resume from. In the present embodiment, as described above, the diagnostic process is performed in synchronization with the first cleaning cycle after the power is turned on. Therefore, as shown in FIG.
When the cleaning cycle is restarted from the beginning by turning on the power again and pressing the operation switch, the diagnostic process is executed together with the cleaning cycle. That is, since the cleaning cycle is restarted at the same time when the operation switch is pressed, the user is not confused with the failure and the time is saved.

Immediately after installing the dishwasher and after performing maintenance, since there is no water in the hot water storage tank 7 or the pipes, when the hot water storage tank 7 is supplied with hot water, air is accumulated in the rinse pump 12 or the like. It may be possible. Then, in particular, when the rinse pump 12 is driven from the state of the overflow water level B of FIG. 4 (B) in order to determine whether the off operation of the overflow switch 21 is good or not, the air retention causes a predetermined time. In some cases, the water level does not drop to the normal position, and the overflow switch 21 may not be turned off although it is normal. In that respect, in the present embodiment, the self-diagnosis of the overflow switch 21 is performed at the time when the initial hot water supply is completed and the cleaning cycle is started. Therefore, during the initial hot water supply, the rinsing pump 12 is already driven a plurality of times and air traps, etc. Since it is in a stable state, and the water level can be smoothly lowered with the driving of the rinse pump 12, it is possible to accurately judge whether the off operation of the overflow switch 21 is good or bad.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition to the above, various modifications can be made without departing from the scope of the invention. (1) The timing for determining whether the ON operation of the overflow switch is good or bad may be any time as long as the rinse pump is not in operation after entering the cleaning cycle. For example, a cleaning operation as indicated by a symbol X in FIG. It may be performed during the down time between the cleaning step and the rinsing step in the cycle, or during racking until the start of the next cleaning cycle, as indicated by the symbol Y. If the pause time is too short, it is possible to make a pass / fail judgment in a short time by increasing the forced water supply amount or lowering the overflow water level. (2) The timing for determining the quality of the OFF operation of the overflow switch only needs to be set after the rinse pump has been driven multiple times during the initial hot water supply, as long as the rinse pump is in a stable state with no air accumulation. May be.

(3) The constant quantity water supply device is a system such as a cistern type in which a float and a valve are combined, and in short, if the structure is such that water is automatically supplied to a predetermined water level. Good. (4) The overflow switch is not limited to the float type, but a pressure sensor may be used to measure the water level from the head, or a sensor based on another principle such as optically measuring the position of the liquid surface may be used. The present invention can be applied to such a thing.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a dishwasher according to an embodiment of the present invention.

FIG. 2 is a sectional view of a hot water storage tank

FIG. 3 is a flowchart of a diagnostic process

FIG. 4 is a cross-sectional view showing changes in water level in the diagnostic process in order.

FIG. 5 is a diagram showing the timing of self-diagnosis.

FIG. 6 is a cross-sectional view showing changes in water level in order in a conventional diagnostic process.

FIG. 7 is a diagram showing the timing of the self-diagnosis.

[Explanation of symbols]

5 ... Washing tank 6 ... Washing pump 7 ... Hot water storage tank 8
… Hot water supply pipe 9… Water valve 11… Float switch 12… Rinse pump 20… Overflow pipe
21 ... Overflow switch A ... Set water level B ... Overflow water level

Claims (3)

(57) [Claims] 1. A washing tank and a hot water storage tank that is provided with a fixed amount water supply mechanism and can store hot water at a set water level. The hot water stored in the hot water storage tank is jetted by a rinsing pump to be collected in the washing tank. step have <br/> rows initial hot water supply for storing the washing water into the washing tank by a plurality of times, and then was stored hot water to the set water level in the hot water storage tank, the washing water in the washing tank a cleaning step of recovering the same washing tank and ejected toward the object to be cleaned by the washing pump, only recovering hot water of the hot water storage tank to the cleaning tank and ejected toward the object to be cleaned by the rinse pump
In a washing machine in which a washing cycle consisting of a rinsing step of replenishing hot water to the set water level in the hot water storage tank is repeatedly executed, the hot water storage tank has an overflow port for overflowing hot water when the set water level is exceeded, A device for detecting whether or not the water level has reached the overflow port, and a device for diagnosing whether or not the detection switch operates normally, forcing the water level in the hot water tank. Forcibly supplying water to the overflow water level, and a judgment means for judging whether or not the detection switch detects that the water level has reached the overflow water level within a predetermined time when the forced water supply means is executed. And the forced water supply means for cleaning after the initial hot water supply.
Of the cycle and before the start of the next cleaning cycle
A diagnostic device for a tank water level detection switch in a washing machine, comprising: a diagnostic execution unit that is executed when the rinse pump is not operating . 2. A washing tank and a hot water storage tank, which has a fixed amount water supply mechanism and can store hot water at a set water level, and the hot water stored in the hot water storage tank is jetted by a rinsing pump to be collected in the washing tank. step have <br/> rows initial hot water supply for storing the washing water into the washing tank by a plurality of times, and then was stored hot water to the set water level in the hot water storage tank, the washing water in the washing tank a cleaning step of recovering the same washing tank and ejected toward the object to be cleaned by the washing pump, only recovering hot water of the hot water storage tank to the cleaning tank and ejected toward the object to be cleaned by the rinse pump
In a washing machine in which a washing cycle consisting of a rinsing step of replenishing hot water to the set water level in the hot water storage tank is repeatedly executed, the hot water storage tank has an overflow port for overflowing hot water when the set water level is exceeded, A device for detecting whether or not the water level has reached the overflow port, and a device for diagnosing whether or not the detection switch operates normally, forcing the water level in the hot water tank. When the rinsing pump is started in a state where the water level is at the overflow water level, the detection switch detects that the water level has dropped from the overflow water level within a predetermined time. The determination means for determining whether or not it has been detected, and the forced water supply means are executed after the initial hot water supply. A diagnostic device for a tank water level detection switch in a washing machine, comprising: 3. The diagnostic device for a tank water level detection switch in a washing machine according to claim 2, wherein the diagnostic execution means is adapted to execute the forced water supply means in association with the cleaning cycle.