JPH0534010B2 - - Google Patents

Description

[Detailed Description of the Invention] In conventional dishwashers, water or hot water is supplied into the tank from the water supply or water heater through a water supply solenoid valve, and if the water supply solenoid valve remains open, the water inside the machine is If the water continues to be supplied, the overflowing water may wet the floor, potentially causing a so-called flooding accident.

This flooding accident can occur even when the dishwasher is not operating, so if treatment is delayed, it can cause major damage.

The present invention provides a safe dishwasher at a low cost that prevents overflow accidents through the operation of a drain pump and prevents the load controlled by an automatic time switch from malfunctioning when the dishwasher is not in operation. It is something to do.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the figure, 1 is a water level detection switch that detects the overflow level in the tank, 2 is a safety switch, 3 is a water level detection switch that detects when the water level in the tank has reached a predetermined water level suitable for cleaning, and 4 is a water level detection switch inside the tank. This is a water supply solenoid valve that supplies water to the tank, and is controlled by the water level detection switch 3. 5 drains water from the tank with a drainage pump.
6 is an automatic time switch that controls processes such as water supply, washing, draining, and rinsing; 6a is a timer drive motor that drives this automatic time switch 6; 7 is a detergent dispenser that dispenses detergent for washing dishes; 8
1 is a finishing agent dispenser for adding a finishing agent in the rinsing process; 9 is a heater that heats the cleaning water and raises the atmospheric temperature in the tank during the drying process; 10 is a cleaning motor; and 11 is for starting the cleaning motor 10. 12 is a temperature fuse for preventing excessive temperature rise of the heater 9, 13 is a thermostat for preventing excessive temperature rise of the heater 9, and 14 is a thermostat for controlling the timer drive motor 6a according to the water temperature. The contacts _T1 to _T8 of the automatic time switch 6 operate as shown in FIG. 2 to control the washing, rinsing, and drying programs.

Fig. 3 shows the structure of a dishwasher. 15 is the main body, 16 is a water supply hose that connects the water supply or water heater to the dishwasher, 17 is a tank that stores the dishes and collects water for washing the dishes, and 18 is the tank 17. A drain pipe 19 connecting the bottom and the drain pump 5 is a drain hose that guides water after washing and rinsing to the outside of the machine. Tap water passes through a water supply hose 16 and a water supply solenoid valve 4, collects in a tank 17, and after being washed and rinsed, is discharged outside the machine through a drain pipe 18 and a drain hose 19 by the action of a drain pump 5. be done.

Here, as shown in FIG. 1, the common terminal of the overflow level detection switch 1 is connected to the drain pump 5.
Further, the normally open contact NO is connected to the power supply, and the normally closed contact NC is connected to the contact B of T6 of the automatic time switch ₆ that controls the normal operation of the drainage pump. Therefore, since a large current to the heater 9 does not flow through the common terminal, the contacts of the overflow detection switch 1 need only have a small current.

In the normal operation of the dishwasher with the above configuration, as shown in FIG. The stroke is thus controlled. In the unlikely event that flooding occurs, the overflow level detection switch 1 is switched to the NO side, and the drain pump 5 is directly connected to the power source to drain water.

Here, when the dishwasher is not in use and overflow occurs, the drain pump 5 is energized by the overflow level detection switch 1, and the automatic time switch 6 is in the "off" state and the contacts T ₁ , T ₂ and Since B of T ₆ is open, power is not turned on to the circuits controlled by the automatic time switch 6, except for the water supply solenoid valve 4, the timer drive motor 6a, the detergent dispenser 7, etc., and the drain pump 5. do not have. Further, if the automatic time switch 6 is viewed as a control device, if the safety switch 2 is turned on, the control device is always energized, and an abnormality notification can be performed in parallel with the overflow prevention operation.

As described above, in the present invention, the overflow prevention operation can be performed reliably not only when the dishwasher is in use but also when the dishwasher is not in use, and furthermore, even during the overflow operation, the power supply to the control device can be maintained. Since it does not turn off, it is possible to notify the user of an abnormality in parallel with the overflow prevention operation. Furthermore, when the dishwasher is not in use, the automatic time switch contacts are open, which prevents power from flowing into electrical components such as the heater and washing motor, causing secondary malfunctions. It is. moreover,
The common contact of the overflow detection switch is connected to the drain pump, and compared to a configuration in which the common contact is connected to the power supply side, current other than the drain pump, such as a large heater current, does not flow through the contact, so the contact has a small capacity. This has the advantage that it can be realized with an inexpensive overflow detection switch.

[Brief explanation of drawings]

Fig. 1 is an electrical circuit diagram of a dishwasher that employs an overflow prevention circuit according to an embodiment of the present invention, Fig. 2 is a diagram showing the contact program of the automatic time switch, and Fig. 3 is a schematic configuration of the dishwasher. FIG. 1... Overflow level detection switch, 2... Safety switch, 4... Water supply solenoid valve, 5... Drain pump, 6...
...Automatic time switch, 17...tank.

Claims (1)

[Claims] 1. A water supply solenoid valve that supplies water into the tank, a water level detection switch that detects when the water level in the tank reaches a predetermined position and stops the operation of the water supply solenoid valve, and a water level that is higher than the water level detected by the water level detection switch. A water overflow detection switch that detects a high water level, a drainage pump that drains water in the tank, and a control means that controls processes such as water supply, washing, and drainage, and a common terminal of the water overflow detection switch is connected to the drainage pump. an overflow prevention device for a dishwasher, wherein the normally open contact of the overflow detection switch is connected to the power supply side, the normally closed contact is connected to the drain pump control terminal of the control means, and the power supply terminal of the control means is connected directly to the power supply. .