JPH041896Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a dishwasher that performs the washing process and the rinsing process by repeating water supply and drainage a plurality of times.

(b) Conventional technology There is a washing machine disclosed in Japanese Patent Publication No. 57-35037 that performs washing and rinsing by repeating water supply and drainage.
Here, drainage abnormalities are investigated by checking whether the drainage time is appropriate.

The above-mentioned appropriate drainage time will be longer than the normal drainage time if the drainage channel is lengthened depending on the location where the washing machine is installed, so it may be determined that there is a drainage abnormality even though it is not, leading to a decrease in reliability. Connect. Therefore, the appropriate drainage time is generally set longer than usual.

On the other hand, in a dishwasher, even if the filter is clogged during draining, the draining time will be longer, but it will finish within the appropriate draining time, and the draining will continue as normal, so it is desirable to detect a clogged filter. I couldn't do it.

(c) Problems to be solved by the invention The invention aims to accurately detect even slight drainage defects (abnormalities) such as filter clogging.

(d) Means for solving the problem The solution according to the present invention is a water level switch that detects the water level in the washing tank in a dishwasher that repeats water supply and drainage multiple times during the washing process and rinsing process. a drainage control section that drives a drainage pump before water supply and ends drainage when the water level switch is turned off within a predetermined drainage time; a water supply control unit that terminates water supply when a switch is turned on; a water supply counter that counts water supply time; and a drainage abnormality counter that counts the number of times the water supply counter counts within a predetermined short time; The water supply control unit is configured to notify a drainage abnormality when the number of counts of the drainage abnormality counter is a predetermined number of times of 2 or more.

(e) Effects Drainage occurs before water is supplied, so if there is a drainage problem, water supply will be terminated within a short period of time. Therefore, when the end of water supply is detected in a short period of time, it can be known that the previous drainage was defective (abnormal). However, since hot water from a water heater or the like is manually poured into the drained cleaning tank, the water supply time becomes zero or short in this case, which is similar to a drainage failure (abnormality). Therefore, since manual water supply (hot water) is not performed frequently during full operation, the number of times water supply completion is detected in a short time is compared with a predetermined number of times of 2 or more, and only when the number of times exceeds a predetermined number is a drainage failure detected. (abnormality)).

(F) Embodiment To explain the following based on the drawings, in Fig. 2, 1 is the main body of a tabletop dishwasher, a door 2 that opens downward is provided at the front opening, and a washing tank 3 is installed inside. It is set up. A tableware basket 4 is placed in the middle of the washing tank 3 so that it can be taken in and out from the front opening. 5 is a mounting rail.

At the bottom of the washing tank 3, an arm nozzle 6 and a sheathed heater 7 that rotate and spray washing water onto the dish basket 4 are arranged, and at the bottom there is a recess 9 in which a removable filter 8 is provided. is formed. 1
0 is a water level detecting means in the cleaning tank 3, which detects the cleaning water level by the vertical movement of the float.
1, an abnormally high water level is detected by an abnormal water level switch 12, respectively. Further, a thermistor 13 for detecting the water temperature in the tank is provided at the outer bottom near the front of the cleaning tank 3, and a door switch 14 for detecting opening/closing of the door 2 is also provided at an appropriate location.

15 is a water supply pipe to the cleaning tank 3 having a water supply valve 16; 17 is a cleaning pump that supplies cleaning water from the recess 9 to the arm nozzle 6, injects it, and circulates it;
20 is a blower that circulates drying air within the tank.

A control box 21 with an operation surface is provided at the lower front of the main body 1, and the operation surface displays text and time (minutes) for each process of prewashing, washing, rinsing, and drying, as shown in FIG. , LED 22 corresponding to each journey... and LED 23 corresponding to each course
..., a drying process time change key 24, a course change key 25, a start key 26 which also serves as a pause key, and a power switch 27 are provided.
In addition, the drying process can be changed to three different times,
LEDs 22 are arranged corresponding to each time.
Each of the keys 24, 25, and 26 is used to sequentially change or alternate the time, course, or stop/start each time it is operated.

The control box 21 contains ROM, RAM,
A control circuit centered around a microcomputer 28 (hereinafter referred to as microcomputer) consisting of a CPU, I/O, etc. is incorporated, and the circuit diagram thereof is shown in FIG.
That is, the microcomputer 28 controls the washing water level switch 11,
Signals are input from the abnormal water level switch 12, thermistor 13, door switch 14, and each key 24, 25, 26, and the sheathed heater 7, water supply valve 16, drain pump 18, cleaning pump 19, blower 20, and LED
An operation signal is output to 22..., 23.... The microcomputer 28 also controls the power switch 27 while it is closed.
It can be output to the AC solenoid 29 or buzzer 30 that opens the signal. Furthermore, microcontroller 2
Reference numeral 8 inputs a detection signal from an overcurrent detection means 31 consisting of a current transformer or the like that detects whether the cleaning pump 19 is locked.

Next, the control operation by the microcomputer 28 will be explained based on the flowchart of FIG. 4. First, after turning on the power switch 27, the initial settings are
32 and call up and set the standard course and time from the ROM 33. And thermistor 1
After checking the disconnection in 3, press the course change key 25 and
Each operation with the drying time change key 24 that is accepted in a mode other than the prewash only course is checked.

The temperature detected by the thermistor 13 is checked regardless of course changes or the operation of the start key 26. At that time, if the abnormal temperature control section 34 composed of the microcomputer 28 detects a temperature of 80°C or higher, it switches the power switch 27 to the AC solenoid. 29 to turn it off. This OFF operation is repeated at predetermined time intervals in case the power switch 27 cannot be turned OFF in one go.
The intermittent operation causes an abnormality notification to be performed.

In addition, the abnormality notification in this embodiment blinks.
The number and type of LEDs are changed to correspond to the abnormality, and the user is informed of the abnormality.

When the course and time are set and the start key 26 is operated, the freeze check flag is checked, and the microcomputer 2 checks whether the temperature detected by the thermistor is 5°C or less.
The freezing control unit 36 consisting of 8. 5
℃ or below, the freezing control unit 36 turns off the cleaning pump 1.
3 seconds counter 37 for 3 seconds when 9 is processed.
Turn it on while counting with , and pump during these 3 seconds.
Overcurrent detection means 3 determines whether overcurrent occurs in the ON state.
Check by 1. When a detection signal is output, the output of the drive system and heating system is immediately turned off, and an abnormality notification is executed. Such an overcurrent is caused by freezing of the pump 1.
This occurs when 9 is locked, and when detected, the progress of the course is automatically stopped.

If 3 seconds pass without any overcurrent being detected, the freeze control unit 36 turns off the pump 19, sets the freeze check flag, and proceeds to the next step. If the detected temperature is not below 5°C, a flag is also set and the process proceeds to the next step.

Thus, if the freeze check flag is set, each process of prewashing, washing, rinsing, and drying is executed by the process control section 38 constituted by the microcomputer 28 according to the set course and time.
In each stroke, the water supply valve 16 is opened to supply water, and when the wash water level switch 11 trips, a wash water level flag is set, and when the abnormal water level switch 12 trips, an abnormal water level flag is set. Further, when the door switch 14 detects that the door 2 is closed, a door flag is set. Further, when the start key 26 is operated to start, a start flag is set, but this start flag is erased when the stop operation and the end of the operation are performed.

When the set course time ends, the start flag is erased and the auto power-off subroutine shown in FIG. That is, when the start flag is turned off, the 10-minute counter 40 starts counting, and when the count increases, the AC solenoid 29 is activated and the power switch 27 is energized to turn off. This AC solenoid 29 is turned on and off for 0.5 seconds and then turned off for 0.5 seconds 10 times. Then, the 10 minute counter 40 is cleared, but if the power switch 27 cannot be turned off due to the activation of the first AC solenoid 29, the 10 minute counter 40 will be counted again until the start key 26 is operated from then on. ,
The power off operation is continued every 10 minutes until the power switch 27 is turned off.

In addition, the abnormal water level flag is set to the abnormal water level switch 12.
If the water level is tripped for 1 second or more, the abnormal water level control section 41 consisting of the microcomputer 28 takes care of the problem.

6 and 7 show a specific circuit of the overcurrent detection means 31 and characteristic diagrams of the comparison voltage _V1 based on the detected current. Here, the current flowing through the cleaning pump 19 is measured by a count transformer CT, smoothed, and compared with a predetermined overcurrent level OCL by a comparator COM. The discharging time of the smoothing capacitor C is longer than the charging time, so that if, for example, a child repeatedly operates the start key 26, the measured level will quickly rise, and in this case as well, an abnormality will be reported and the child may be mistreated. can be taught.

The washing process in the designated (selected) course is explained in the flowchart of FIG. Here, after checking the numerical value 2 indicating the content of washing, first a subroutine for checking the washing water level switch 11 shown in FIG. 9 is executed. A drainage control section 45 constituted by a microcomputer 28 drives the drainage pump 18 when the wash water level flag is set even though there is no water supply end flag. In normal usage, there should be no wash water in the tank, so there is no wash water level flag (wash water level switch 11 has been reset).
If you manually add water (hot water), the wash water level flag will go up. When the pump 18 drains water, if the switch 11 is normal, the drain counter 46 is reset and the flag disappears by the time the drain counter 46 counts 30 seconds, and if it is abnormal, the flag remains. If it is normal, the pump 18 is stopped, and if it is abnormal, the system output is stopped and notified.

On the other hand, the water supply subroutine shown in FIG. 10 is executed by the water supply control section 42 constituted by the microcomputer 28. Here, after checking the water supply end flag and the wash water level flag, the water supply valve 16 is opened and the addition contents of the water supply counter 43 are checked. If there is no manual water supply (hot water), the switch 11 is not actually checked, so does the wash water level flag go up (does the switch 11 trip)?
is being investigated. When the flag is raised, the water supply control unit 42 supplies water until 2 seconds later, closes the water supply valve 16, and stops the water supply counter 43. thus,
If the flag is raised before the water supply counter 43 counts 2 minutes, a water supply end flag is raised.

However, since manual water supply (hot water) is not performed many times during one operation, the counter 43
When the drainage abnormality counter 44 counts four or more times that the content (water supply time) is within 10 seconds, this is determined to be a poor drainage condition, and the water supply control unit 42 issues an abnormality notification as a drainage abnormality. At the same time, system output is stopped. Furthermore, the water supply control section 42
If the water supply counter 43 counts 2 minutes or more and the wash water level flag does not go up, the switch 11 or the water supply system is notified of an abnormality, the water supply valve 16 is closed, the drain pump 18 is driven, and other operations are performed. System output is stopped.

When the checks of the switch 11, the water supply system, and the drainage system are completed, the temperature control section constituted by the microcomputer 28 checks the water temperature, sets a temperature check flag, and sets a time reduction flag if the water temperature is already 60°C or higher.

The washing process control section 38 first controls the washing pump 19.
The water temperature is checked, and if it is not above 60°C, the heater 7 is energized, and if it is above 60°C, the heater 7 is turned off. However, once the water temperature reaches 60℃ or higher,
Set the temperature reached flag. When the 12 minute counter 47 counts in this manner, the 12 minute elapsed flag is set and the time reduction flag is checked. If the time reduction flag is set (when the initial water temperature is 60℃ or higher),
The cleaning pump 19 and the heater 7 are stopped, the course content is changed to numeric value 3 indicating rinsing, and a drainage subroutine is executed.

On the other hand, if the initial water temperature is not 60°C or higher, if the water temperature reaches 60°C or higher once and the reaching flag is set, the water will be cleaned when the 1-minute counter 48 counts up another 12 minutes. The pump 19 and heater 7 are stopped.

Furthermore, if city water is used as is from the beginning, as long as the arrival flag does not go up after 12 minutes (the temperature has not reached 60°C or higher), the washing process will continue until the water temperature reaches 60°C or higher. After the temperature reaches 60° C. or higher, when the one minute counter 48 counts up, the cleaning pump 19 and the heater 7 are stopped.

Note that the degree of cleaning can be changed by changing the 1 minute counter 48 to a 10 minute counter or the like.

The next rinsing process is similar to the washing process, and is executed twice, with the heater 7 turned off the first time, and the heater 7 turned on and off the next time using hot water at 70°C.

of the heater 7 in the washing process and the rinsing process.
ON-OFF control is performed by a heater control section 49 comprised of a microcomputer 28 based on the flowchart of FIG. That is, if the heater 7 is ON,
Thermistor detection temperature is 60℃ (washing process), 70℃
The 5-second counter 50 is cleared until the 5-second counter 50 is reached (rinsing process), but when the 5-second counter 49 is reached, the 5-second counter 49 starts counting, and when the count is up, the heater 7 is turned off. on the other hand,
If the heater 7 is off, the counter 50 is cleared while the temperature is reached, but when the temperature drops, the counter 50 starts counting, and when the count is up, the heater 7 is turned on. As a result,
Even if the temperature detected by the thermistor fluctuates or quickly changes in temperature, the heater 7 will be turned on and off with a delay of 5 seconds (changeable). This phenomenon can be suppressed.

In the next drying process, the drying process control section 38 drives the blower 20 and causes the heating control section 52 to control the heater 7 while the counter 51 counts the set time. That is, the heating control section 52
As shown in the flowchart in Figure 12, when the process time is set to 15 minutes, it is equivalent to 400W (heater 7 is turned on for 10 seconds and turned off for 19 seconds), and when it is set to 30 minutes, it is equivalent to 300W for the next 15 minutes. Equivalent (10 seconds ON - 28 seconds
OFF), when the setting is 60 minutes, the heater 7 is controlled so that the last 30 minutes is equivalent to 50W (10 seconds ON - 220 seconds OFF). The drying temperature is set at 70°C.

Note that when the drying only course is specified, the heating control unit 52 turns on the heater 7 during the time set by the counter 51.
is controlled with the equivalent of 300W (10 seconds ON - 28 seconds OFF).

The end determination of the set stroke time is executed when the start flag by the start key 26 is set, and when the start flag is set, the buzzer 30 is used to notify that the set stroke time has ended, but it is not executed when the start flag is not set. First, return the operation to the diagram.

(G) Effects of the invention According to the invention, it is possible to accurately detect drainage abnormalities (defects) such as filter clogging, distinguishing it from manual water supply, and to prevent a decrease in the degree of cleaning due to filter clogging in advance. In addition, hot water from a water heater or the like can be used, making it possible to provide an extremely hygienic and practical dishwasher.

[Brief explanation of the drawing]

Fig. 1 is a control block diagram of the dishwasher according to the present invention, Fig. 2 is an internal mechanism diagram, Fig. 3 is a front view of the operation panel, and Fig. 4 is a flowchart for explaining the main operations of the whole. Figure 5 is a flowchart for explaining the auto power off operation;
Figure 7 is an electric circuit diagram of the overcurrent detection means, Figure 7 is a characteristic diagram of comparison voltage based on detected current, Figures 8, 9, and 10 are flowcharts for explaining the operation of the washing process. FIG. 11 is a flowchart for explaining the operation of heater control, and FIG. 12 is a flowchart for explaining the operation of the drying process. 3... Washing tank, 6... Arm nozzle, 7... Heater, 11... Washing water level switch, 13... Thermistor, 16... Water supply valve, 18... Drain pump,
19...Washing pump, 22, 23...LED, 2
4...Drying time change key, 25...Course change key, 26...Pause/start key, 27...
Power switch, 28...Microcomputer, 29...AC
Solenoid, 30...Buzzer, 31...Overcurrent detection means, 43...Water supply counter, 44...Drainage abnormality counter, 42...Water supply control unit.

Claims (1)

[Scope of utility model registration request] In a dishwasher that repeatedly performs water supply and drainage multiple times during the washing and rinsing stages, there is a water level switch that detects the water level in the washing tank, and a drain pump is driven before water is supplied to adjust the water level within a predetermined drainage time. A drainage control unit that ends drainage when the switch is turned off; a water supply control unit that supplies water to the cleaning tank during water supply after completion of drainage; and a water supply control unit that ends water supply when the water level switch is turned on; and a water supply control unit that counts the water supply time. The water supply control unit includes a water supply counter and a drainage abnormality counter that counts the number of times the water supply counter counts within a predetermined short period of time, and the water supply control unit is configured to control the drainage abnormality counter when the number of counts is 2 or more. A dishwasher characterized in that a drainage abnormality is notified when a predetermined number of times is reached.