JP4726645B2 - Device for preventing malfunction of water level detector in dishwasher - Google Patents

Description

  The present invention relates to a device for preventing a malfunction (operation failure) of a float type water level detector of a dishwasher, and can prevent a malfunction due to significant contamination of the water level detector. is there.

In a dishwasher equipped with a float-type water level detector, the flow of dirty washing water into and out of the water level detector is repeated, so that significant dirt (due to leftovers, etc.) adheres to the float, etc. The detector may malfunction.
When the water level detector malfunctions, the water level detection accuracy is lowered, and when the water level detection accuracy is lowered, the water level of the supplied cleaning tank is not constant, and thus a serious problem such as a reduction in the cleaning effect occurs. For this reason, the malfunction of the water level detector is a problem that must be avoided as much as possible.
Therefore, as a countermeasure to this problem, a cleaning course for cleaning the float type water level detector (hereinafter referred to as “water level detector”) is provided, and when this cleaning course is selected, the supplied water is distributed to the water level detector. There is a device that cleans the water level detector (for example, Japanese Patent Laid-Open No. 2000-316784, Prior Art 1), and when the water is supplied to the cleaning tank, the water level detector is supplied for a predetermined time. The water level detector is washed every time water is supplied to prevent the dirt from adhering to the float or the like of the water level detector (Japanese Utility Model Laid-Open No. 58-11451, Prior Art 2). ).

  In the above prior art 1, since the water level detector is cleaned when the user selects the cleaning course, the cleaning is not actually performed for a long period of time. As a result, the contamination of the water level detector becomes remarkable. In the conventional technique 2, the water level detector is frequently passed for cleaning for a certain period of time every time the water is supplied, so that the water level detector is frequently vibrated by the cleaning. The operation of the float switch may become unstable due to repeated vibration. For this reason, it is necessary to perform the above-mentioned cleaning to the minimum necessary level.

In addition, recent dishwashers are program-controlled by a control device using a microcomputer, and can perform "cleaning with detergent" and "cleaning without detergent", and multiple driving courses are programmed and set in advance. The course can be selected as appropriate.
In an actual general household, cleaning with a detergent and cleaning without a detergent are appropriately performed, and the cleaning without a detergent is often repeated continuously even if the tableware is very dirty.
JP 2000-316784 A Japanese Utility Model Publication No.58-11451

  Accordingly, an object of the present invention is to devise a cleaning control method so that the cleaning of the water level detector by water supply is effectively performed with the minimum necessary amount.

Means for solving the above problems are controlled by a control device using a microcomputer, and can be operated in a cleaning course with a detergent or a cleaning course without a detergent, and a plurality of driving courses are programmed and set in advance. Assuming a dishwasher that is designed to detect and control the water level in the washing tank with a float-type water level detector, it is possible to select which driving course to execute as follows. To (d).
(A) A switching valve is provided on the downstream side of the water supply valve for supplying water to the cleaning tank. The switching valve switches the water supply to the cleaning tank, introduces it into the water level detector, and performs the cleaning through the water level detector. The tank is filled with water,
(B) When a washing course without detergent is selected, it has a counter that adds this number of selections.
(C) When the cleaning course with detergent is selected, or when the number of continuous selections of the cleaning course without detergent reaches a predetermined number, the control device has a reset means for resetting the counter,
(D) If the number of times of continuous selection of the detergent without washing course reaches the plant constant number, that the control device is adapted to introduce the water level detector feedwater by switching the switching valve.

  The dishwasher's float-type water level detector communicates with the drainage chamber at the bottom of the washing tank, and the dirty washing water enters and exits it. The operation of the vessel becomes unsmooth and the possibility that the water level detector malfunctions increases. However, when “washing with detergent” (washing with washing water containing detergent) is repeated, even if the washing water is heavily soiled, there is almost no dirt on the water level detector, and malfunction due to marked dirt adhesion It was found that there is no possibility of On the other hand, if “cleaning without detergent” is repeated many times on a table that is heavily soiled, the above-mentioned contamination (for example, adhesion to the float surface) becomes noticeable and the water level detector malfunctions. However, if water supply is introduced into the water level detector after "cleaning without detergent" is repeated several times, the water level detector is thereby cleaned and cleaned. It was found that no malfunction occurred.

  In the present invention, when a washing course without detergent is selected many times in succession, this is counted, and when the count reaches a predetermined number of times, the switching valve is switched in the next water supply process to supply water to the water level detector. Since it is introduced and cleaned, it is possible to prevent the malfunction of the water level detector due to significant dirt adhesion. On the other hand, when the washing course without detergent is selected a predetermined number of times in succession, the water supply is automatically introduced into the water level detector at the time of water supply in the dish washing course. The above-described cleaning does not hinder the smooth operation of the float, and thus the reliability of the operation of the water level detector is improved.

  In addition, from the viewpoint of preventing malfunction of the water level detector due to dirt, the above “predetermined number” is preferably small. On the other hand, from the viewpoint of preventing malfunction of the water level detector due to cleaning, the above “predetermined number” is More is desirable. In addition, the above “predetermined number of times” has a limit value that causes malfunction, and if it exceeds that, it will definitely cause malfunction, and if it is less than that, it will not cause malfunction at all. Then, the possibility becomes remarkable. Therefore, taking into account the current state of use of dishwashers in most homes, a large amount of dishes (for example, the standard tableware quantity for a family of five) is washed on a washing course without detergent, although it is very dirty. Assuming the case, the “predetermined number of times” is preferably about 30 times.

When the number of consecutive cleaning courses without detergent is reached, the operation panel prompts you to select the cleaning course with detergent and prompts you to select the cleaning course with detergent. It is also possible to avoid as much as possible the cleaning of the water level detector which is performed by selecting the cleaning course continuously a predetermined number of times.
By doing in this way, at the stage where the number of continuous selections of the cleaning course without detergent reaches a predetermined number, the cleaning course with detergent is selected and the detergent is put in before the start button is pressed. As a result, the cleaning operation for the water level detector is avoided.

An embodiment in which the present invention is applied to a drawer type dishwasher will be described with reference to FIGS.
A water supply pipe h is connected to a washing tank H supported on a side wall of the dishwasher main body (casing) by a rail so as to be freely drawn out, and an electromagnetic water supply valve 8 is provided in the water supply pipe h.
The washing tank H is provided with a drain pump 4, a washing pump 10, a heater 11, a rotating nozzle 12, a drying fan 15, a water level switch 9 and the like, and the tableware is stored in the tableware basket 1 in the washing tank.
There is a drainage chamber J at the bottom of the cleaning tank H, and a suction pipe 10a of the cleaning pump 10 is connected to the drainage chamber J, and a suction pipe 4a of the drainage pump 4 is connected thereto.
Further, an introduction pipe 9a of a water level detector S provided with a water level switch 9 and a float 9f is connected to the drainage chamber J.
The water supply pipe 10 b of the cleaning pump 10 is connected to the entrance of the rotary nozzle 12, and the water supply pipe 4 b of the drainage pump 4 is connected to a drainage pipe outside the machine via a drainage trap 6 and a drainage check valve 7. .

  The electromagnetic water supply valve 8 is opened and the cleaning water is directly supplied from the water supply pipe h to the cleaning tank H. Since the washing water in the washing tank H flows into the water level detector S through the introduction pipe 9a, the water level in the water level detector S rises and the float 9f rises as the water level in the washing tank H rises. When the float rises to a predetermined position, the water level switch 9 is closed, the water supply electromagnetic valve 8 is closed, and water supply is stopped. When the water supply process is completed, a predetermined cleaning process is performed according to the cleaning program. During the cleaning operation, the cleaning water in the cleaning tank H is ejected from the rotary nozzle 12 through the residual vegetable filter 13, the drainage chamber J, the suction pipe 10a, the cleaning pump 10, and the water supply pipe 10b and returned to the cleaning tank H again.

In the drainage process, the cleaning water in the cleaning tank H is discharged outside the machine through the suction pipe 4a, the drainage pump 4, and the water supply pipe 4b of the drainage pump 4.
And what kind of driving | running | working course is performed is selected with the operation panel P provided in the front surface of the washing tank H. FIG.
The operation panel P is also provided with a power button 2 and a start / pause button 5.
In addition, a standard course, a rapid washing course, a careful course, a detergent-free course, a prewash course, and a drying course are prepared as the driving course, and these are appropriately selected before the start operation by the start button. The “standard course, rapid washing course, and careful course” are “cleaning courses with detergents”, and the “course without detergents” and the “prewash courses” are “washing courses without detergents”.

The above is the structure with which the conventional drawer-type dishwasher is equipped.
In this embodiment, a three-way electromagnetic valve (switching valve) 20 is provided in the water supply pipe h on the downstream side of the water supply electromagnetic valve 8, and the water supply pipe is provided above the water level detector S via the three-way electromagnetic valve 20 and the cleaning pipe 21. h, and usually the three-way solenoid valve 20 is in the first position, and water is supplied directly from the three-way solenoid valve 20 to the cleaning tank H via the water supply pipe h (the feed water flow rate is about every second in this embodiment). 1.4m). When the three-way solenoid valve 20 is switched to the second position, the water supply is introduced into the water level detector S via the three-way solenoid valve 20 and the cleaning pipe 21, and the water level detector S, the introduction pipe 9 a, and the drainage chamber J. Then, water is supplied to the cleaning tank H for a predetermined time, whereby the water level detector is cleaned.
The three-way solenoid valve 20 and the water supply solenoid valve 8 can be unitized.

In this embodiment, when the washing course without detergent is continuously selected n times and a start operation is performed, the three-way solenoid valve 20 is switched to the second position, and water supply to the water level detector is started. After s seconds, the water supply is switched to the first position again, the water supply to the water level detector S is stopped, and the water supply pipe h is directly supplied to the washing tank again.
In this embodiment, n is 30 times and s is 15 seconds.

When the detergent-free cleaning course is selected, it is transmitted from the detergent-free cleaning course selection signal transmitting means 51 provided in the control device of the operation panel P, and this is counted by the counter 52 provided in the control device. When the count value of the counter 52 reaches a predetermined number of times set in the memory 53, the control means (CPU) 54 of the control device detects this and switches the three-way solenoid valve 20 to the second position. Further, a reset signal is transmitted from the control means 54 to the counter 52, and the counter 52 is reset.
On the other hand, when “cleaning course with detergent” is selected, the counter 52 is reset by a reset signal from the control means 54.
As described above, since the “detergent-free cleaning course” is prevented from being repeated n times in succession, the malfunction of the water level detector due to significant contamination is reliably prevented.

Further , when the washing course without detergent is selected n times in succession , as described above, the water supply to the water level detector S is immediately switched by switching the three-way solenoid valve 20 to the second position (water level detector side). Instead of starting , the control means (CPU) 54 issues a warning signal to display on the display of the operation panel P to select “cleaning course with detergent” and to prompt the selection of the cleaning course with detergent. You can also.

An example of the flow of switching control of the three-way solenoid valve 20 is as shown in FIG.
That is, when the power switch is turned on and an operation course is selected (S1), it is confirmed whether it is a “detergent-free cleaning course” (S2). If it is a “cleaning course with detergent”, the counter is reset, and the three-way solenoid valve 20 is held in the first position (position toward the washing tank). It is confirmed whether or not “course” has been selected a predetermined number of times (S3). If it is not the predetermined number of times, the three-way solenoid valve 20 is held in the first position. If it is the predetermined number of times, the three-way solenoid valve 20 is switched to the second position (position toward the water level detector), and the counter 52 is reset.
The counter 52 does not literally mean a counter, but means means for adding and storing (or registering).
In this embodiment, the cleaning course without detergent is referred to as “detergent-free course” and “pre-washing course”, but the course includes driving courses without using detergent in other courses.
In addition, although the cleaning course with detergent is referred to as “standard course”, “quick washing course”, and “careful course”, it goes without saying that courses that use detergent in other courses are also included.

These are sectional drawings of an Example. These are block diagrams of the control apparatus of the electromagnetic switching valve of an Example. These are flowcharts explaining the cleaning process of a water level detector.

Explanation of symbols

H: Washing tank h: Water supply pipe J: Drainage chamber
P: control panel S: water level detector 1: tableware basket 2: power button 3: start / pause button 4: drain pump 4a: suction pipe 4b: water pipe 6: drain trap 7: drain check valve 8: water supply electromagnetic Valve 9: Water level switch 9a: Introduction pipe 9f: Float 10: Washing pump 10a: Suction pipe 10b: Water supply pipe 11: Heater 12: Rotating nozzle 13: Leftover filter 15: Drying fan
20: Three-way solenoid valve (electromagnetic switching valve)
21: Cleaning pipe 51: Cleaning course selection signal transmission means without detergent 52: Counter 53: Memory 54: CPU
55: Cleaning course selection signal transmission means with detergent

Claims (2)

It is controlled by a control device with a microcomputer and can be operated by selecting a cleaning course with or without a detergent, and multiple driving courses are programmed, and which driving course is selected as appropriate. A dishwasher designed to detect and control the water level in the washing tank with a float-type water level detector,
A switching valve is provided on the downstream side of the water supply valve for supplying water to the cleaning tank, and the switching valve switches water supply to the cleaning tank and introduces it into the water level detector, and supplies water to the cleaning tank via the water level detector. And
When a washing course without detergent is selected, it has a counter that adds this number of selections,
When the cleaning course with the detergent is selected, or when the number of consecutive selections of the cleaning course without the detergent reaches a predetermined number, the control device has reset means for resetting the counter,
If the number of times of continuous selection of the detergent without washing course reaches the plant constant number, dishwasher, characterized in that has a feed water by switching the switching valve so as to introduce into the water level detector by the control device. When the number of continuous selections of the cleaning course without detergent reaches the predetermined number, the operation panel is displayed to select the cleaning course with the detergent, prompting the selection of the cleaning course with the detergent , and selecting the cleaning course. 2. The dishwasher according to claim 1, wherein cleaning of the water level detector, which is performed when the number of continuous selection of the none cleaning course reaches the predetermined number, is avoided.

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