JP4542065B2 - Dishwasher - Google Patents

Description

  The present invention relates to a dishwasher that cleans tableware stored in a washing tank, and more particularly to a dishwasher that uses zero power during standby when not in operation.

  Conventional dishwashers are equipped with a relay circuit that turns the power supply to the control circuit on and off in order to reduce the power consumption when the operation is turned off. When the operation is turned off, the relay circuit stops the power supply to the control circuit. When the operation switch connected to the commercial power source and the overflow detection switch are used to monitor the operation on and flooding, the charging circuit is always operated from the commercial power source to generate the power to drive the relay circuit. The relay circuit is operated to supply power to the control circuit (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2002-65567 (page 4-6, FIG. 1)

  However, in the conventional dishwasher, when the operation switch and the overflow detection switch connected to the commercial power supply are not operated and the operation detection and the overflow are monitored, it is necessary to generate a power supply for monitoring. Since it is composed of a capacitor voltage dividing circuit and a rectifier circuit and an alternating current always flows from the commercial power supply, there is a problem that the power cannot be reduced to zero.

  The present invention has been made to solve the above-described problems, and a first object is to obtain a dishwasher capable of reducing standby power to zero, and a second object is standby. The dishwasher which can ensure the safety of time is obtained.

A dishwasher according to the present invention includes a washing tub provided in a washing machine main body for storing tableware, a washing means for washing the tableware, a water supply means for supplying washing water to the washing means, and the inside of the washing tub Heating means for heating the washing water and air for drying the tableware, draining means for draining the washing water in the washing tank, control for controlling the washing means, the water supply means, the heating means and the drainage means And a power supply circuit that is connected to a commercial power supply and supplies a DC power to the control means, and a charging circuit that is charged by the output of the power supply circuit, each connected to the charging circuit, An operation switch for starting operation, a water leakage detection circuit for detecting water leakage from the washing tank, a voltage drop detection circuit for detecting voltage drop of the charging circuit, the operation switch, the water leakage detection circuit, and A power supply circuit starting circuit for starting the power supply circuit by an input signal from at least one of the voltage drop detecting circuits, and an abnormality detecting circuit for detecting an abnormality other than the water leakage during standby when the cleaning operation is not performed And the control means operates the cleaning means, the water supply means, and the heating means when the input signal when the power supply circuit is activated includes the input signal from the operation switch. Operating the drainage means when the input signal includes the input signal from the water leakage detection circuit, and when the input signal includes the input signal from the voltage drop detection circuit, When there is no input signal from the operation switch, at least check for the presence of an input signal from the abnormality detection circuit, and input signal from the abnormality detection circuit When there is to stop the control operation.

According to the present invention, a power supply circuit that is connected to a commercial power supply and supplies DC power to the control means, a charging circuit that is charged by the output of the power supply circuit, and an operation switch that is connected to the charging circuit and starts operation At least one of a water leakage detection circuit for detecting water leakage from the cleaning tank, a voltage drop detection circuit for detecting a voltage drop of the charging circuit, the operation switch, the water leakage detection circuit, and the voltage drop detection circuit. A power supply circuit starting circuit for starting the power supply circuit by an input signal from, and an abnormality detection circuit for detecting an abnormality other than the water leakage during standby when the cleaning operation is not performed, the control means, When the input signal when starting the power supply circuit includes the input signal from the operation switch, the cleaning means, the water supply means, and the heating means Operating the drain means when the input signal includes the input signal from the leak detection circuit, and detecting the leak when the input signal includes the input signal from the voltage drop detection circuit. When there is no input signal from the circuit and the operation switch, at least the presence or absence of an input signal from the abnormality detection circuit is checked, and when there is no input signal from the abnormality detection circuit, the control operation is stopped. Since the control means performs control according to the input signal when the power supply circuit is activated, the standby power can be reduced to zero, and the power supply circuit is activated even if the voltage of the charging circuit is lowered. , The charging circuit operates, and safety during standby can be ensured.

FIG. 1 is a cross-sectional view showing the structure of a dishwasher according to an embodiment of the present invention.
In the figure, a door 2 is attached to an upper opening of a dishwasher body 1 of the dishwasher, and a washing tub 3 is incorporated in the dishwasher body 1. In addition, a water supply device 4 is provided on the side surface of the washing tub 3 to supply water used for washing and rinsing from the outside of the dishwasher main body 1 into the washing tub 3. A drainage device 5 that discharges the water in the cleaning tank 3 used for the cleaning, and a cleaning pump 6 that is a cleaning means for circulating the cleaning water in the cleaning tank 3 and injecting the cleaning water into the cleaning tank 3 from the cleaning nozzle 7 And the heater 8 which is a heating means which heats the washing water in the washing tank 3 and the air which dries the tableware 17 is provided.

In addition, a control circuit 9 to which a commercial power supply 10 is connected is provided at the lower part of the dishwasher main body 1, and an operation switch 11 and a buzzer 12 as a notification means are connected to the control circuit 9 through a wiring 15a. A water supply device 4, a drainage device 5, a cleaning pump 6, and a heater 8 are connected via a wiring 15b.
Further, the control circuit 9 is attached to the inner side surface of the washing tub 3 to detect a water level in the washing tub 3, and is attached to the inner bottom surface of the dishwasher body 1 to leak water from the washing tub 3. A water leakage detection circuit 14 is connected to detect. The water level detection circuit 13 detects a standard water amount necessary for cleaning supplied from the water supply device 4. In addition, a basket 16 for storing tableware 17 is provided in the cleaning tank 3.

FIG. 2 is a block diagram showing the configuration of the control circuit 9. Parts that are the same as or equivalent to those in FIG.
In FIG. 2, the control circuit 9 is provided with a power supply circuit 20 for converting an AC voltage from a commercial power supply 10 into a low DC voltage. The power supply circuit 20 is composed of a switching power supply circuit and is input AC The voltage and the output DC voltage are electrically insulated. The output of the power supply circuit 20 is connected to the power supply of the microcomputer 21 which is a control means. The microcomputer 21 is connected to the output of the microcomputer 21 through the wiring 15b with the water supply device 4, the drainage device 5, the washing pump 6, and the heater 8. Connected and performs cleaning sequence control. Note that a DC voltage that is an output of the power supply circuit 20 is indicated by 22. Further, drive circuits for the water supply device 4, the drainage device 5, and the cleaning pump 6 are omitted.

  Further, a buzzer 12 is connected to the output of the microcomputer 21, a water level detection circuit 13 is connected to the input, and the cleaning pump 6, the heater 8 and the drainage device 5, and the temperature detection circuit during standby when the cleaning operation is not performed. (Not shown), an abnormality detection circuit 18 for detecting an abnormality of the water level detection circuit 13 and the like, an operation switch 11 and a water leakage detection circuit 14 are connected. Although not shown, the abnormality detection circuit 18 includes a motor rotation detection unit such as a cleaning pump 6 and a drainage device, an abnormality detection unit of a temperature detection circuit, and the like. When there is an input and the motor is rotating, it is determined that the cleaning pump 6 is abnormal, and the abnormality detection means of the temperature detection circuit is input when the temperature detection circuit is input even though the heater 8 is not included. Therefore, it is determined that the temperature detection circuit is abnormal.

  A charging circuit 23 is connected to the output of the power supply circuit 20. Connected to the charging circuit 23 are a voltage drop detection circuit 24, an operation switch 11, and a water leakage detection circuit 14 that input a charging voltage of the charging circuit 23 and detects a voltage drop of the charging voltage. In addition, the output of the voltage drop detection circuit 24 and the output signals of the operation switch 11 and the water leakage detection circuit 14 are input, and the power supply circuit activation circuit operates to output when any one of the three input signals is an ON signal. An OR circuit 25 is provided, and the power supply circuit 20 is activated by the output of the OR circuit 25.

  FIG. 3 is a circuit diagram showing a specific circuit example of the control circuit 9. In the figure, a power supply circuit 20 uses a switching power supply circuit as described above, and automatically starts and stops depending on the load state (output impedance). In the charging circuit 23, a series circuit of a diode 23a, a charging resistor 23b, and a capacitor 23c, and a series circuit of a Zener diode 23d and another charging resistor 23e are connected in parallel to the charging resistor 23b. The capacitor 23c uses a large-capacity electrolytic capacitor called a spar capacitor. The capacitor 23c may be an electric double layer capacitor, or a secondary battery such as a nickel metal hydride battery has the same effect.

  The voltage drop detection circuit 24 includes a voltage comparison circuit 24a, resistors 24b and 24c that divide the voltage of the capacitor 23c of the charging circuit 23, and a threshold voltage 24d. The voltage comparison circuit 24a outputs “L” when the (+) input voltage is lower than the (−) input voltage, and outputs “H” when the (+) input voltage is higher than the (−) input voltage. Accordingly, when the capacitor 23c is sufficiently charged, the output of the voltage drop detection circuit 24 is “L”, and when the voltage of the capacitor 23c drops and falls below the threshold value 24d, “H” is outputted. . The threshold voltage is set to a voltage at which the voltage drop detection circuit 24 can operate.

The OR circuit 25 includes resistors 25a, 25b, and 25c, transistors 25d, 25e, and 25f, and base resistors 25g, 25h, and 25f. The base resistor 25g of the OR circuit 25 is connected to the capacitor 23c of the charging circuit 23 via the operation switch 11, the base resistor 25h is connected to the capacitor 23c of the charging circuit 23 via the water leakage detection circuit 14, and the base resistor 25i is connected to the voltage comparing circuit 24a. Each is connected to an output. The resistors 25a, 25b, and 25c are selected to have relatively low resistance values. The operation switch 11 is a switch that closes the contact when the user presses it and returns to the original state when the press is stopped.
The water leakage detection circuit 14 is composed of two electrodes 14a and 14b. In a normal state, the resistance between the electrode 14a and the electrode 14b is high. However, if water enters between the electrode 14a and the electrode 14b, both the electrodes It operates so that the resistance value between them decreases. The electrode 14a is connected to the capacitor 23c, and the electrode 14b is connected to the base resistor 25h.

Next, the operation of the present embodiment will be described using the operation flowchart of the microcomputer 21 shown in FIGS.
First, the capacitor 23c in the charging circuit 23 is sufficiently charged and the operation of the dishwasher is stopped, that is, the operation of the state will be described. At this time, since the microcomputer 21 is in a stopped state, the power supply circuit 20 is unloaded and the power supply circuit 20 also maintains the stopped state.
Now, for example, when an abnormality occurs in the water supply device 4 due to foreign matter caught in the water supply valve, water accumulates in the washing tank 3, and water leaks from the washing tank 3 to the dishwasher main body 1. Since the water enters between the electrodes 14a and 14b of the water leakage detection circuit 14 installed on the bottom surface of 1 and the resistance value between the electrodes 14a and 14b decreases, the water leakage detection circuit 14 and the base resistance 25h are reduced from the capacitor 23c. Thus, a base current flows through the transistor 25e, and the transistor 25e is turned on. When the transistor 25e is turned on, the resistor 25b is connected to the power supply circuit 20 as a load. Therefore, the power supply circuit 20 is activated, for example, performs a boosting operation and supplies a voltage to the microcomputer 21. When voltage is applied to the microcomputer 21, the microcomputer 21 operates and executes the flowchart shown in FIG.

  First, in step S30, the state of the water leakage detection circuit 14 is input to determine the presence or absence of water leakage. In this case, since the transistor 25e is turned on, that is, the water leakage detection circuit 14 detects water leakage, the process proceeds to step S31 to perform water leakage processing. In the water leakage treatment, the drainage device 5 is driven to discharge the water accumulated in the cleaning tank 3 to the outside. Next, the process proceeds to step S32, and the alarm buzzer 12 is driven. As a result, the failure or expansion of the electronic circuit of the device due to the occurrence of water supply abnormality is prevented.

Then, the case where the driving | operation of a dishwasher is started is demonstrated. Also in this case, for convenience of explanation, it is assumed that the capacitor 23c in the charging circuit 23 is sufficiently charged.
The user opens the door 2 of the dishwasher, places the tableware 17 in the basket 16, puts detergent into the washing tub 3, closes the door 2, and presses the operation switch 11. When the contact of the operation switch 11 is closed, a base current flows from the capacitor 23c to the transistor 25d through the operation switch 11 and the base resistor 25g, and the transistor 25d is turned on. Then, since the resistor 25a connected to the transistor 25d is connected as a load of the power supply circuit 20, the power supply circuit 20 is activated and simultaneously the microcomputer 21 is activated, and the flowchart shown in FIG. 4 is executed.

  First, since there is no water leakage, the water leakage detection circuit 14 does not detect water leakage, the transistor 25e is off, it is determined that there is no water leakage in step S30, the flow proceeds to step S33, and the operation switch 11 is determined to be on in step S33. Therefore, the process proceeds to step S34. In step S34, a cleaning process is executed.

The cleaning process will be briefly described. First, the water supply device 4 is driven to supply water required for cleaning to the cleaning tank 3. When the water level detection circuit 13 detects a predetermined water level, the driving of the water supply device 4 is stopped, and the heater 8 is driven to heat the water in the cleaning tank 3 to a predetermined temperature. Thereafter, the cleaning pump 6 is driven to rotate and spray the cleaning water from the cleaning nozzle 7 to clean the dishes 17 that are non-food items. After cleaning for a predetermined time, the drainage device 5 is driven to discharge the cleaning water used for cleaning in the cleaning tank 3 to the outside. This series of steps is repeated 2-3 times to complete the washing step, and then the drying step is performed.
When the cleaning process is completed, the process proceeds to step S35 and the operation of the microcomputer 21 is stopped. When the operation of the microcomputer 21 stops, the power supply circuit 20 enters a no-load state and the power supply circuit 20 also enters a stop state. Therefore, the power of the dishwasher is zero.
During the cleaning process, the capacitor 23c is charged via the diode 23a and the charging resistor 23b by the output voltage from the power supply circuit 20.

Next, a case where the standby state time becomes long and the voltage of the capacitor 23c in the charging circuit 23 decreases will be described.
When the voltage of the capacitor 23c decreases, the voltage divided by the resistors 24b and 24c becomes lower than the threshold voltage 24d, and the output of the voltage comparison circuit 24a becomes "H". When the output of the voltage comparison circuit 24a becomes “H”, a base current flows to the transistor 25f via the base resistance 25i of the OR circuit 25, and the transistor 25f is turned on. Since the resistor 25c becomes a load of the power supply circuit 20, the power supply circuit 20 is activated, the microcomputer 21 is activated, and the flowchart shown in FIG. 4 is executed.

  In the flowchart of FIG. 4, in step S30, since the water leakage detection circuit 14 is not operating, it is determined that there is no water leakage. In step S33, the operation switch 11 is not operating, so it is determined that the operation is not operating, and the process proceeds to step S36. In step S36, the input of the abnormality detection circuit 18 connected to the microcomputer 21 is checked. For example, when there is an input from the motor rotation detection means, when the motor is rotating, it is determined that the cleaning pump 6 is abnormal, and when there is an input from the temperature detection means, the temperature detection means is abnormal. In step S37, the end of inspection is determined. If the inspection has not ended, the process returns to step S30 and step S33 to determine water leakage and operation.

  Therefore, if there is water leakage during the inspection, the process proceeds to step S31, and if the operation switch 11 is pressed during the inspection, the process proceeds to step S34. If it is determined in step S37 that the inspection has been completed, it is determined in step S38 whether an abnormality has been detected in the inspection result. If an abnormality is detected, the process proceeds to step S32 to give an alarm. If not abnormal, the process proceeds to step S35 and the operation of the microcomputer 21 is stopped. When the operation of the microcomputer 21 stops, the power supply circuit 20 enters a no-load state, and the power supply circuit 20 also enters a stop state. Therefore, the power of the dishwasher is zero. During the execution of the inspection sequence, the capacitor 23c is charged by the output voltage from the power supply circuit 20 via the diode 23a and the charging resistor 23b.

  At the time of installing the dishwasher, the capacitor 23c in the charging circuit 23 is not charged. Therefore, in the series circuit of the diode 23a, the Zener diode 23d, and the charging resistor 23e, the applied voltage of the Zener diode 23d increases, and the Zener diode 23d is turned ON. The capacitor 23c is charged through the path of the Zener diode 23d and the charging resistor 23e. For this reason, the charging resistor 23e is set to a relatively low resistance value. At the same time, the microcomputer 21 is started, but the inspection is executed as described above.

  As described above, the cleaning tank 3 provided in the tableware washing machine main body 1 for storing the tableware 17, the cleaning pump 6 for cleaning the tableware 17, and the water supply device 4 for supplying cleaning water to the cleaning pump 6 and the like The heater 8 for heating the cleaning water in the cleaning tank 3 and the air for drying the dishes 17, the drainage device 5 for draining the cleaning water in the cleaning tank 3, the cleaning pump 6, the water supply device 4, the heater 8 and the drainage In a dishwasher comprising a microcomputer 21 that controls the apparatus 5 and a power circuit 20 that is connected to the commercial power source 10 and supplies DC power to the microcomputer 21, a charging circuit 23 that is charged by the output of the power circuit 20 And an operation switch 11 for starting operation, a water leakage detection circuit 14 for detecting water leakage from the cleaning tank 3, and a voltage drop in the charging circuit 23. An OR circuit 25 that activates the power supply circuit 20 by an input signal from at least one of the voltage drop detection circuit 24 and at least one of the operation switch 11, the water leakage detection circuit 14, and the voltage drop detection circuit 24. The microcomputer 21 performs control according to the input signal when the power supply circuit 20 is activated, so that the standby power can be reduced to zero, and even if the voltage of the charging circuit 23 decreases, the power supply circuit 20 Is activated, the microcomputer 21 is activated, the charging circuit 23 is operated, and safety during standby can be ensured.

  In addition, the microcomputer 21 is provided with an abnormality detection circuit 18 for detecting an abnormality other than water leakage during standby when the cleaning operation is not performed, and the microcomputer 21 receives an input signal from the operation switch 11 when the power supply circuit 20 is activated. When the signal is included, the cleaning pump 6 and the like, the water supply device 4 that supplies the cleaning water to the cleaning pump 6 and the like, the heater 8 that heats the cleaning water in the cleaning tank 3 and the air that dries the dishes 17, The drainage device 5 that drains the cleaning water in the cleaning tank 3 is operated, and the drainage device 5 is operated when the input signal includes the input signal from the water leakage detection circuit 14. When there is no input signal from the water leakage detection circuit 14 and the operation switch 11, at least the presence of the input signal from the abnormality detection circuit 18 is checked to detect an abnormality. When there is no input signal from the road 18, since the stop control operation, it is possible to standby power to zero, and can ensure safety during standby.

Further, the buzzer 12 is provided, and the microcomputer 21 operates the buzzer 12 if there is an input from the water leakage detection circuit 14 or an input from the abnormality detection circuit 18, so that the cleaning pump 6, the water supply device 4, the heater 8, It is possible to prevent failure or expansion damage of the electronic circuit of the dishwasher due to the occurrence of an abnormality in the drainage device 5.
Although not shown, the commercial power supply 10 may be shut off by providing a shut-off means for shutting off the commercial power supply 10 after the buzzer 12 has operated for a certain period of time.

It is a block diagram of the dishwasher which shows embodiment of this invention. It is a block diagram of the control circuit of the dishwasher of embodiment of this invention. It is a circuit diagram of the control circuit of the dishwasher of embodiment of this invention. It is a flowchart which shows operation | movement of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tableware washing machine body, 3 washing tank, 4 water supply apparatus, 5 drainage apparatus, 6 washing pump, 7 washing nozzle, 8 heater, 9 control circuit, 10 commercial power supply, 11 operation switch, 12 buzzer, 14 leak detection circuit, 17 Tableware, 18 abnormality detection circuit, 20 power supply circuit, 21 microcomputer, 23 charging circuit, 24 voltage drop detection circuit, 25 OR circuit.

Claims (2)

A washing tank provided in the washing machine body for storing tableware;
A cleaning means for cleaning the tableware;
Water supply means for supplying cleaning water to the cleaning means;
Heating means for heating washing water in the washing tank and air for drying the tableware;
Drainage means for draining the wash water in the washing tank;
Control means for controlling the cleaning means, the water supply means, the heating means and the drainage means;
A power supply circuit connected to a commercial power supply for supplying DC power to the control means;
In the dishwasher with
A charging circuit charged by the output of the power supply circuit;
An operation switch connected to each of the charging circuits to start operation, a water leakage detection circuit for detecting water leakage from the cleaning tank, and a voltage drop detection circuit for detecting a voltage drop of the charging circuit,
A power supply circuit starting circuit for starting the power supply circuit by an input signal from at least one of the operation switch, the water leakage detection circuit, and the voltage drop detection circuit;
Abnormality detection for detecting any one or more abnormality among the cleaning means, the heating means, the drainage means, and the water level detection means for detecting the water level in the cleaning tank during standby when the cleaning operation is not performed. and a circuit,
The control means includes
When the input signal when the power supply circuit is activated includes the input signal from the operation switch, the cleaning unit, the water supply unit, and the heating unit are operated, and the input signal is output from the water leakage detection circuit. The drainage means is operated when the input signal is included, and when the input signal includes the input signal from the voltage drop detection circuit, and there is no input signal from the water leakage detection circuit and the operation switch. A dishwasher characterized by checking at least the presence or absence of an input signal from the abnormality detection circuit and stopping the control operation when there is no input signal from the abnormality detection circuit. Providing a notification means,
The control means, the input signal from the leakage detection circuit, or dishwashing machine according to claim 1, wherein the operating the informing means if there is an input signal from the abnormality detecting circuit.

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