JP3245909B2 - dishwasher - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to heater heating control during the drying process of a dishwasher.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for shortening the drying time of dishwashers.

[0003] A conventional dishwasher will be described below. FIG. 1 (shared with the embodiment) shows the configuration of a conventional dishwasher. As shown in FIG. 1, a cleaning nozzle 4 for injecting cleaning water by a pump 3 driven by a motor 2 is provided on the bottom of the cleaning tank 1, and a drying fan 5 is mounted on a side surface. A heater 6 is provided at a lower portion of the washing nozzle 4 and a table basket 7 is provided at an upper portion. A temperature detector 8 and an excessive temperature rise prevention device 9 are provided at the bottom of the cleaning tank 1, and a control device 10 for controlling energization of the heater 6 is provided outside the cleaning tank 1.

The operation of the dishwasher constructed as described above will be described below.

When the dishwasher enters the drying process after the washing and rinsing processes, high-temperature washing water is sprayed onto the dishes by the cleaning nozzle 4, and then the drying heater 6 is energized to perform heating and drying. Exhausting. The heater 6 is energized by the control device 10 as shown in FIG.
The intermittent energization of OFF is performed and is performed within a range that does not reach the high cut temperature Tc of the temperature detecting device 8. When the input value of the heater 6 becomes large due to a voltage fluctuation or the like and the temperature in the cleaning tank 1 exceeds the high cut temperature Tc, the power supply to the heater 6 is cut off, and when the temperature falls to the reset temperature of the temperature detecting device 8, the power supply is performed again. . At this time, the temperature in the cleaning tank 1 overshoots due to the residual heat of the heater 6, and exceeds the high cut temperature Tc to reach Tca. When the overshoot temperature Tca exceeds the set temperature Th for preventing damage to dishes and the like of the overheat prevention device 9, the operation of the dishwasher is stopped by the control device 10.
For this reason, Tc is lowered by providing a certain temperature difference with Th so that Tca does not exceed Th.

[0006]

However, in the above-mentioned conventional configuration, the temperature difference between the high cut temperature Tc of the temperature detecting device 8 and the set temperature Th of the overheat prevention device 9 becomes large, and the overshoot temperature Tca becomes Th. , So that the drying temperature is lowered and the tableware drying time is lengthened. When the temperature in the washing tank 1 exceeds Tc,
Since the temperature in the washing tank 1 drops to the reset temperature of the temperature detection device 8, there is a problem that the degree of drying of the tableware deteriorates.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a dishwasher capable of shortening a drying time.

[0008]

In order to achieve this object, a dishwasher according to the present invention comprises a heater for heating air in a washing tank.
And a temperature detecting device for detecting the temperature in the cleaning tank.
And an over-temperature prevention device, and controlling the energization of the heater.
A control device for controlling the heater by the control device.
In the on-off energization control of a fixed cycle,
The temperature detection device is set to a temperature at which the overheat prevention device operates.
When a near constant temperature is detected, the temperature control device
Change to a shorter cycle than the fixed cycle ON-OFF and
When the temperature in the cleaning tank reaches the set temperature of the temperature detecting device by controlling the power supply to the heater, the O
The N-OFF intermittent energization cycle is shortened.

[0009]

With this configuration, the temperature in the cleaning tank exceeds the set temperature of the conventional temperature detection device and changes in a saturated state at a temperature close to the conventional overshoot temperature. The amount of heat can be increased.

[0010]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 2, the heater 6 in the drying process
The power is supplied to the heater 6 at a constant cycle of ON for a1 hour and OFF for b1 hour. When the temperature in the cleaning tank 1 reaches the high cut temperature Tc of the temperature detecting device 8, the control device 10 turns on the power to the heater 6. , ON is a2 hours, OFF is b2 hours,
a1> a2, b1> b2, and the ON-OFF cycle interval is shortened.

The operation of the dishwasher configured as described above will be described with reference to FIG. First, when the drying process is started after the rinsing process, the power supply to the heater 6 is turned on.
OFF is performed at a fixed cycle a1, b2 time, and the cleaning tank 1
When the internal temperature reaches Tc, the heater 6 is turned on and off.
The energization period is shortened to a2 and b2.

As described above, according to the present embodiment, the cleaning tank 1
When the temperature in the inside reaches Tc, the ON-OFF energization cycle interval to the heater 6 is shortened, and the temperature in the washing tank 1 changes at a temperature close to the saturation state close to Tca, so that the total amount of heat applied to the tableware is reduced. It becomes larger than before and the drying time can be shortened.

Reference Example Hereinafter, a reference example according to the present invention will be described with reference to the drawings. The same components as those in the conventional example are denoted by the same reference numerals, and description thereof is omitted.

As shown in FIG. 3, during the drying process, the heater 6
When the temperature in the cleaning layer 1 reaches the high cut temperature Tc of the temperature detection device 8, the control device 1
The input value to the heater 6 is sequentially reduced in a plurality of steps by 0.

The operation of the dishwasher configured as described above will be described with reference to FIG. First, in the drying step after the rinsing step, the heater 6 is continuously energized, and when the temperature in the cleaning layer 1 reaches Tc, the heater 6 is turned on.
Are sequentially lowered in a plurality of steps, and the heat value of the heater 6 is sequentially reduced.

As described above , when the temperature in the cleaning tank 1 reaches Tc, the input value of the heater 6 sequentially drops in a plurality of stages, and the calorific value decreases, so that the saturation in the cleaning tank 1 approaches Tca. Since the temperature changes with the temperature, the total amount of heat applied to the tableware becomes larger than before and the drying time can be shortened.

[0018]

As is clear from the invention of the above embodiment, according to the present invention, when the temperature in the cleaning tank reaches the high cut temperature Tc of the temperature detecting device in the drying process, O
The N-OFF energization cycle is shortened, and the temperature in the cleaning tank changes at a temperature close to the saturation temperature close to the conventional overshoot temperature Tca.

[Brief description of the drawings]

FIG. 1 is a sectional view of a dishwasher according to a first embodiment of the present invention.

FIG. 2 is a temperature-time characteristic diagram of a washing tank in a drying process of the dishwasher.

FIG. 3 is a temperature-time characteristic diagram in a washing tank of a dishwasher according to a reference example of the present invention.

FIG. 4—Temperature in washing tank during drying process of conventional dishwasher—
Time characteristic chart

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning tank 8 Temperature detection device 6 Heater 9 Overheat prevention device 10 Control device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A47L 15/42 A47L 15/46 A47L 15/48 G05D 23/19 G05D 23/24

Claims (1)

(57) [Claims] 1. A heater for heating air in a washing tank, a temperature detecting device for detecting a temperature in the washing tank, an overheating prevention device, and a control device for controlling energization of the heater, The heater is controlled by the above-described control device for a fixed period of O2.
In the N-OFF energization control, when the temperature detection device detects a constant temperature close to the temperature at which the over-temperature prevention device operates, the temperature control device uses a cycle shorter than the constant cycle ON-OFF. dishwasher which is adapted to control the energization of the heater instead of.