JP6683512B2 - Dishwasher - Google Patents

Description

  The present invention relates to a dishwasher / dryer equipped with an electric heater.

  In general, a dishwasher / dryer is equipped with an electric heater which is used both for heating washing water for washing dishes and for heating air for drying dishes. The electric heater is turned on / off by a relay.

  In this type of dishwasher / dryer, a relatively large current is supplied to the electric heater so that the washing water and the drying air can be quickly heated. Further, in the electric heater, ON / OFF of energization is repeated many times during the cleaning operation and the drying operation, and the number of times of opening / closing of the relay for turning ON / OFF the energization of the electric heater is relatively large.

  For this reason, a means for detecting a failure such as a contact abnormality of the relay is provided, and when a failure of the relay is detected, the fact is notified by an error display or the operation of the dishwasher is stopped. To ensure safety (see, for example, Patent Document 1).

JP, 2003-220008, A

  By the way, a failure of a relay connected to an electric heater of a dishwasher / dryer is not always a contact failure due to the contact reaching the end of its life (exceeding 200,000 guaranteed operation times of the relay). Even if it has not reached the end of its life, it may be detected as a failure. In this case, the circuit board on which the relay is mounted may be abnormal (for example, a short circuit or disconnection of the harness), but a non-faulty relay may be replaced during maintenance or the faulty part may be identified during maintenance work. There was an inconvenience that it took time and effort.

  In view of the above points, an object of the present invention is to provide a dishwasher / dryer capable of accurately determining a failure due to the contact life of a relay that opens and closes for supplying power to an electric heater.

The present invention relates to a washing tank for storing dishes, an electric heater for heating wash water during a dish-washing operation, and a drying air during a dish-drying operation, and energizing and closing the electric heater. A relay that is turned on / off by a control unit, an operation control unit that controls a cleaning operation and a drying operation, and an indicator that displays information related to control of the operation control unit. A counting unit that counts the total number of times, a storage unit that stores the cumulative number of times of operation of the relay counted by the counting unit, a relay failure detection unit that detects a failure of the relay , and a display that controls the display of the display. and a control unit, the display control unit, when a failure of the relay by the relay failure detecting section is not detected, without displaying the cumulative operation times of the relay in which the storage unit is stored in the display When the relay failure detection unit detects a failure of the relay, it is possible to determine whether or not the failure of the relay is due to the contact life, and the cumulative number of operations of the relay stored in the storage unit. Is displayed on the display .

  According to the present invention, it is possible to confirm the cumulative number of times of operation of the relay displayed on the display when the relay failure detecting unit detects the failure of the relay. As a result, it is possible to accurately determine whether or not the failure of the relay is due to the contact life, and it is possible to reduce the time and effort to specify the failure point during maintenance work.

  Further, in the present invention, the operation control unit, when the relay failure detection unit detects a failure of the relay, the cumulative operation number of the relay stored in the storage unit exceeds a guaranteed operation number of the relay. It is characterized by including an operation prohibition unit that prohibits the cleaning operation and the drying operation in the case of the above.

  According to the present invention, the operation prohibition unit prohibits the cleaning operation and the dry operation when the cumulative number of relay operations when the relay failure detection unit detects a relay failure exceeds the guaranteed operation count. As a result, it is possible to prevent the relay from being continuously used when the failure of the relay is the life of the contact.

  Further, in the present invention, the operation control unit executes a relay protection control for reducing the number of opening / closing operations of the relay when the cumulative number of operations of the relay stored in the storage unit exceeds a predetermined number. And

  The cumulative number of relay operations (predetermined number) when performing relay protection control is less than the guaranteed number of relay operations, exceeds the guaranteed number of relay operations, or is less than the guaranteed number of relay operations. And when the number of guaranteed operations of the relay is exceeded. As the relay protection control, operation control such as prolonging the interval of energization of the electric heater or lowering the control temperature for the electric heater so as to reduce the number of times of opening and closing the relay during operation can be mentioned.

  According to this, the number of times the relay is opened and closed when the relay protection control is executed is reduced, so that the period until the relay reaches the end of its life (the period in which an error is considered to occur) can be extended.

Explanatory drawing which shows schematic structure of the dishwasher of embodiment of this invention. The block diagram which shows the functional structure of the controller in this embodiment. The flowchart which shows the operation | movement which concerns on the failure of the heater relay of the operation control part in this embodiment.

  An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the dishwasher / dryer 1 of the present embodiment includes a housing 2 and a cleaning tank 3 housed inside the housing 2. The dishwasher / dryer 1 of the present embodiment is a built-in type, and the housing 2 is installed in a system kitchen. The cleaning tank 3 can be pulled out from the housing 2 by gripping the handle portion 5 of the front panel 4. In the vicinity of the handle portion 5 of the front panel 4, operation switches 6 and an indicator 7 for indicating an operating state are provided. A controller 8 and a buzzer 9 are housed in the space between the front panel 4 and the cleaning tank 3.

  The upper surface of the cleaning tank 3 is open, and when located inside the housing 2, the upper surface is closed by the lid plate portion 10. The lid plate portion 10 includes a seal member 11. When the cleaning tank 3 is closed by the lid plate portion 10, the seal member 11 is in close contact with the upper edge of the cleaning tank 3 to form a watertight closed state.

  The lid plate portion 10 is attached to the top surface of the housing 2 via an elevating mechanism (not shown), moves upward in association with the drawing operation of the cleaning tank 3 from the housing 2, and separates from the cleaning tank 3.

  The dish tank W is loaded and unloaded from the upper surface of the cleaning tank 3 which is opened by being pulled out from the housing 2. Inside the cleaning tank 3, a tableware basket 12 that supports the tableware W and a cleaning nozzle 13 that ejects cleaning water toward the tableware W are provided.

  Further, the cleaning tank 3 includes an electric heater 14 for heating water (cleaning water and rinse water) and air in the cleaning tank 3, a temperature sensor 15 for detecting the temperature of the cleaning tank 3, a pump 16, and a drying fan 17. It is provided.

  The pump 16 injects the water in the cleaning tank 3 from the cleaning nozzle 13 to circulate the water in the normal rotation operation, and discharges the water in the cleaning tank 3 via the residual food filter 18 and the drain pipe 19 in the reverse rotation operation.

  The drying fan 17 sends drying air into the cleaning tank 3 via the intake duct 20a. At this time, by operating the electric heater 14, the drying air sent into the cleaning tank 3 is heated, and the tableware W is dried. The drying air sent into the cleaning tank 3 by the drying fan 17 is exhausted from the ventilation port 20b above the front surface of the cleaning tank 3.

  As shown in FIG. 2, the controller 8 has, as a function, an operation control unit 21 that controls a cleaning operation and a drying operation (hereinafter, simply referred to as operation) of the dishwasher / dryer 1. The controller 8 is composed of an electronic circuit unit and includes a large number of electronic / electrical parts, but includes a heater relay 22 (relay) as a part related to the gist of the present invention. The heater relay 22 opens and closes the contacts in accordance with an instruction (current control) from the operation control unit 21, and the opening / closing operation turns ON / OFF the power supply to the electric heater 14.

  Then, the operation control unit 21 has, as a function related to the gist of the present invention, the storage unit 23 configured by various storage medium groups for recording the control program and various information, and the cumulative number of opening / closing operations of the heater relay 22. Counting unit 24, a relay failure detection unit 25 that detects a failure of the heater relay 22, a display control unit 26 that displays the cumulative number of operations of the heater relay 22 stored in the storage unit 23 on the display unit 7, and A driving prohibition unit 27 that prohibits driving is provided as a function.

  The counting unit 24 counts the number of opening / closing operations of the heater relay 22 during operation, and writes the cumulative value in the storage unit 23.

  The relay failure detection unit 25 detects a high resistance value when a large energization amount is detected in a state where the contact of the heater relay 22 is opened, and a high resistance value is detected in a state where the contact of the heater relay 22 is closed. At this time, it is determined that the heater relay 22 is out of order.

  When the relay failure detection section 25 detects a failure of the heater relay 22, the display control section 26 displays the cumulative number of operations stored in the storage section 23 on the display unit 7.

  When the relay failure detection unit detects a failure of the heater relay 22, the operation prohibition unit 27 determines that the cumulative operation number of the heater relay 22 is the guaranteed operation number of the heater relay 22 (200,000 times in the present embodiment). If it exceeds the limit, driving is prohibited.

  Here, the operation related to the failure of the heater relay 22 by the operation control unit 21 will be described with reference to the flowchart of FIG.

  When the operation is started by the user, the operation control unit 21 starts monitoring the heater relay 22, and in STEP 1, the counting unit 24 samples the opening / closing operation of the heater relay 22 and counts the cumulative number of operations. Next, the operation control unit 21 proceeds to STEP2, stores the cumulative number of operations counted by the counting unit 24 in the storage unit 23, and proceeds to STEP3.

  When the operation control unit 21 proceeds to STEP 3, the relay failure detection unit 25 determines the failure of the heater relay 22, and if the failure of the heater relay 22 is not detected, the operation control unit 21 returns to STEP 1 to detect the failure of the heater relay 22. If yes, go to STEP 4.

  When the relay failure detection unit 25 detects the failure of the heater relay 22, the operation control unit 21 proceeds to STEP 4, and the display control unit 26 displays a display (error display) indicating that an error has occurred on the display unit 7. Then, in STEP 5, the cumulative number of opening / closing operations of the heater relay 22 stored in the storage unit 23 is displayed on the display 7, and the operation is stopped in STEP 6. As described above, when the relay failure detection unit 25 detects the failure of the heater relay 22, the display is displayed on the display unit 7. Therefore, the cumulative operation number of the heater relay 22 can be easily confirmed, and the occurrence of an error in the heater can be confirmed. It is possible to easily determine whether it is due to the relay 22 for use or due to other parts.

  Subsequently, the operation control unit 21 proceeds to STEP7. In STEP 7, if the cumulative number of operations of the heater relay 22 is equal to or more than the guaranteed number of operations (200,000 times in this embodiment), it is considered that the heater relay 22 cannot be used. Then, the operation is prohibited by the driving prohibition unit 27. The prohibition of the operation in STEP 8 is limited unless a relatively large-scale repair such as the replacement of the heater relay 22 or the circuit board on which the heater relay 22 is provided is performed and the error is canceled by a special operation. The operation cannot be restarted.

  On the other hand, in STEP 7, if the cumulative number of operations of the heater relay 22 does not reach the guaranteed number of operations or more, a temporary malfunction of the heater relay 22 or a failure of a component other than the heater relay 22 (for example, wiring). It is possible that a short-circuit, a disconnection, or other minor repair can cause recovery. Therefore, the operation control unit 21 proceeds to STEP 9 and maintains the stop in a state where the stop can be released.

  In the present embodiment, the operation prohibiting unit 27 is provided to prohibit the operation when the cumulative operation number of the heater relay 22 is equal to or more than the guaranteed operation number (200,000 times in the present embodiment). Although the heater relay 22 that has reached the end of its life is prevented from being used continuously, even if the operation prohibition unit 27 is not provided, the cumulative number of operations of the heater relay 22 is displayed, It is possible to prompt the repair (replacement of the substrate, etc.) of the heater relay 22 which has reached the end of its life.

  In addition, between STEP2 and STEP3, when the cumulative number of operations of the heater relay 22 reaches a predetermined number, the operation control unit 21 notifies that fact and reduces the number of times the electric heater 14 is energized so that the heater It is possible to interpose the step of performing relay protection control by reducing the number of times the relay 22 is opened and closed.

  The steps of performing relay protection control are specifically as follows. When the cumulative operation number of the heater relay 22 reaches 70% of the guaranteed operation number (140,000 times in the present embodiment), the ON time of the electric heater 14 during the drying operation is shorter than the OFF time thereafter. To do. That is, in the normal drying operation, both the ON time and the OFF time of the electric heater 14 are 30 seconds, but the ON time is set in the drying operation after the cumulative operation number of the heater relay 22 reaches 140,000 times. Interval control is performed with 15 seconds and OFF time of 60 seconds. According to this, the number of operations of the heater relay 22 can be reduced.

  Further, as another specific example of the relay protection control, the control temperature of the heater relay 22 may be lowered during the dry operation after the cumulative operation number of the heater relay 22 reaches 70% of the guaranteed operation number. . That is, in the normal drying operation, when the temperature detected by the temperature sensor 15 reaches 55 ° C., the electric heater 14 is turned on, and when it reaches 60 ° C., the electric heater 14 is turned off, but the cumulative number of times the heater relay 22 is operated is 140,000 times. During the subsequent drying operation, control is performed such that the temperature is turned on at 40 ° C and turned off at 45 ° C. According to this, the number of operations of the heater relay 22 can be reduced.

  Alternatively, as another specific example of the relay protection control, the drying time by the drying operation after the cumulative operation number of the heater relay 22 reaches 70% of the guaranteed operation number may be set to be long. That is, in the normal drying operation, the drying time is 60 minutes, but after the cumulative number of operations of the heater relay 22 reaches 140,000, the drying time is controlled to 120 minutes. According to this, the number of operations of the heater relay 22 can be reduced while maintaining the drying performance. In the control for reducing the number of operations of the heater relay 22 depending on the ON / OFF time of the electric heater 14, the temperature, and the drying time, which is mentioned as the relay protection control, the cumulative number of operations of the heater relay 22 is 70% of the guaranteed number of operations ( You may perform simultaneously after a predetermined number of times).

  Further, the timing for executing the relay protection control is not limited to the time when the cumulative number of operations of the heater relay 22 exceeds 70% of the guaranteed number of operations, and may be executed less than 70%.

  If no error is detected in the heater relay 22 in STEP 3, the operation control unit 21 notifies the fact that the cumulative number of operations has reached the guaranteed number of operations, and also during both cleaning and drying operations. It is also possible to perform the control for keeping the energization OFF to the heater relay 22 (without turning the energization ON) as a relay protection control for reducing the number of times of operation of the heater relay 22. Alternatively, the relay protection control for reducing the number of operations of the heater relay 22 is performed by the operation control unit 21 to extend the drying time to 180 minutes after the accumulated number of operations reaches the guaranteed number of operations without detecting an error. May be executed as

  W ... Tableware, 1 ... Dishwasher / dryer, 3 ... Washing tank, 7 ... Indicator, 14 ... Electric heater, 21 ... Operation control section, 22 ... Heater relay (relay), 23 ... Storage section, 24 ... Count Section, 25 ... Relay failure detection section, 26 ... Display control section, 27 ... Operation prohibition section.

Claims (3)

A washing tank that stores dishes, an electric heater that heats the wash water during the dish washing operation and the drying air when the dishes are dried, and the power to the electric heater is turned on / off by an opening / closing operation. A relay for controlling the cleaning operation and the drying operation, and an indicator for displaying information on the control of the operation controller,
The operation control unit includes a counting unit that counts the cumulative number of times of opening and closing operations of the relay, a storage unit that stores the cumulative number of times of operation of the relay counted by the counting unit, and a relay failure detection that detects a failure of the relay. And a display control unit that controls the display of the display ,
When the relay failure detection unit does not detect a failure of the relay, the display control unit does not display the cumulative operation number of the relay stored in the storage unit on the display unit, and the relay failure detection unit performs the operation. When a failure of the relay is detected, it is possible to determine whether or not the failure of the relay is due to the contact life, and to display the cumulative operation number of the relay stored in the storage unit on the display. A dishwasher / dryer characterized in that In the dishwasher / dryer according to claim 1,
When the relay failure detection unit detects a failure of the relay, the operation control unit performs a cleaning operation when the cumulative operation count of the relay stored in the storage unit exceeds the guaranteed operation count of the relay. A dishwasher / dryer, which further comprises an operation prohibition unit for prohibiting a dry operation. In the dishwasher / dryer according to claim 1 or 2,
The dishwasher / dryer, wherein the operation control unit executes a relay protection control that reduces the number of opening / closing operations of the relay when the cumulative number of operations of the relay stored in the storage unit exceeds a predetermined number of times. .