JPH0811108B2 - Dishwasher - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dishwasher for washing dishes, and is particularly characterized by a heating system for washing water.

2. Description of the Related Art A conventional dishwasher has a structure as shown in FIG. 3, for example. That is, in heating and cleaning the dishes 1 stored in the cleaning tank 2, the cleaning water stored in the bottom of the cleaning tank 2 is pressurized and circulated by the pump 3 and simultaneously sprayed from the spray nozzle 5 while being heated by the underwater heater 4. Was done by In addition, the tableware is dried by circulating the drying air and providing a heat exchanger in the circulation path to dehumidify the water in the circulating air and heat it, that is, the ventilation provided in the cleaning tank 2. A heat exchanger 12 having a cooling fan 11 in a ventilation circulation passage 8 communicating with the ports 9 and 10, a circulation fan 6 and a heater 7 are provided to circulate the humid air in the cleaning tank 2 and cool it by the heat exchanger 12. The tableware was dried by dehumidifying and warm air generated by the circulation fan 6 and the drying heater 7.

Further, without forming an air circulation path, air is supplied from the outside of the washing tank, and hot air is generated by the fan and drying heater provided in the ventilation path and blown into the washing tank to heat and dry the dishes. The method is also seen. As another example of drying, an underwater heater provided at the bottom of the washing tank for heating the washing water is air-baked, and external air is supplied to the inside of the cleaning tank by a separately provided fan, and the heater is heated by air-heating. It has also been done for a long time to dry dishes by sending air.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in any of the conventional examples described above, hot air generated by a fan and a heater provided in a ventilation passage is blown into a washing tank to heat and dry dishes, and the heater is It is configured as a dedicated drying heater that operates only when tableware is dried, and in order to heat the wash water, another heat source such as an underwater heater in the wash water must be provided separately, which complicates the cost. I didn't get it.

Also, in the case where the underwater heater for heating the wash water is air-baked and also serves as the heater for drying, when the air-baking operation is continued, the heater surface temperature reaches a high temperature of several hundreds of degrees Celsius, and the components near the heater, for example, the cleaning Take heat measures to prevent damage to the tank wall, spray nozzle, tableware storage basket, and ensure the heat resistance of the plastic and wooden tableware stored, and the tableware will fall from the storage basket and come into contact with or near the heater. As a safety measure to prevent accidents such as damage or burning, the surface temperature of the heater does not immediately drop due to residual heat even after the completion of air-drying. There is a drawback in that it is necessary to take measures such as a safety mechanism to prevent accidental touch when taking out tableware. That is, temperature control is performed to suppress the surface temperature when the heater is air-baked to a temperature that does not affect the surrounding structural members, or a sufficient space distance between the heater and the surrounding structural members is maintained, or the surrounding area of the heater is shielded. It was necessary to take heat measures such as providing a heat barrier.

In addition, if the underwater heater for heating the wash water has a dielectric breakdown for some reason, the charging part of the heater and the wash water will be short-circuited and there will be a leakage of electricity to the wash water. Was there.

In view of the above points, the present invention provides a dishwasher having a high safety and a simple structure by heating washing water without using an underwater heater.

Means for Solving the Problems A dishwasher according to the present invention includes a washing tank for storing and washing dishes, an injection nozzle provided in the washing tank, and at least two ventilation ports opened in the washing tank. And a ventilation path that connects these ventilation openings and has a first ventilation opening that can be opened and closed in a part thereof, a blower and a heating element that are arranged in this ventilation path, and a cleaning tank and the outside. With a second ventilation port to
During the cleaning process, the first ventilation port is closed, and warm water generated by the operation of the blower and the heating body is circulated through the ventilation passage to heat the cleaning water, and during the drying process, the first ventilation is performed. While opening the mouth and taking in air, warm air generated by the operation of the blower and the heating body is blown into the cleaning tank through the ventilation passage,
The table is dried by exhausting air from the second ventilation port.

Action The present invention is a dishwashing process of washing dishes stored in the washing bath with the above-mentioned configuration with the jet washing water from the jet nozzle, in the washing bath through the ventilation passage by the operation of the blower and the heating body. The warm air sent into the cleaning tank from the ventilation port opened inside heats the jet cleaning water and the tableware in the cleaning tank which are jetted from the jet nozzle. That is, at this time, the first ventilation port closes the damper, and the hot air directly contacts the jet cleaning water to perform heat exchange to radiate heat to become low-temperature air, and then to the intake side of the blower. The inside of the ventilation passage is sucked through a ventilation port opened in the communicating washing tank, and is again heated by the heating body to become high-temperature air. The warm air is circulated while exchanging heat between the ventilation passage and the inside of the washing tank.

Further, in the tableware drying process, the damper of the first ventilation port is opened, the outside air is sucked into the ventilation passage by the drive of the blower, and the heating body heats and dries it and then sends it into the washing tank. Dry the dishes inside. The damp air after drying the dishes is discharged to the outside of the dishwasher through the second ventilation port, and the outside air is taken into the washing tank and discharged to perform drying.

As described above, at the time of spray washing the dishes, the wash water and the dishes are heated and dried by circulating hot air in the washing tank, and when the dishes are dried, the outside air is taken into the washing tank, The tableware is dried by releasing the low-temperature and high-humidity warm air that has dried the tableware to the outside again.

Example Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a vertical sectional view of a dishwasher according to an embodiment of the present invention. In FIG. 1, 15 is a tableware, 16 is a cleaning tank for storing and cleaning the tableware 15 installed in a basket 25, and 17 is a pressurizing circulation of cleaning water 18 stored at the bottom of the cleaning tank 16. A washing pump for causing 19 to inject the washing water 18 pressurized by the washing pump 17 into the washing tank 16 so as to be rotatably locked, and 20 and 21 are provided at the side portions of the washing tank 16, respectively. Each ventilation port to be opened, 22 is a ventilation path communicating with each of the ventilation ports, in the ventilation path 22 is a blower 23,
A heating body 24 located on the discharge side of the blower 23 is provided. In addition, the ventilating passageway is connected to the first
Is a damper that opens and closes the first ventilation port 26 by a drive source, and 28 is a second ventilation port provided in the lid 29 of the cleaning tank 16. It should be noted that there may be two or more ventilation ports 20 and 21.

The operation of the dishwasher of the present embodiment configured as described above will be described below.

First, when the cleaning water 18 stored in the cleaning tank 16 is pressurized by the cleaning pump 17 and supplied to the spray nozzle 19, the spray nozzle 19 sprays the cleaning water 18 and rotates by the reaction force of the spray cleaning water. While the dishes 15 are stored in the washing tank 16
Spray and wash everywhere. At this time, the damper 27 is closed, and the ventilation passage 22 circulates warm air together with the cleaning tank 16. The washing water after the jet washing returns to the bottom of the washing tank 16 by gravity, is pressurized by the washing pump 17 again, is jetted from the jet nozzle 19, and is circulated in the washing tank 16. In general, warm water is required to enhance the cleaning power for dishware that is soiled, and therefore the cleaning water is heated. Therefore, the blower 23 and the heating body 24 are operated at the same time as the above-mentioned jet cleaning operation, and the generated high temperature air is blown into the cleaning tank 16 through the first ventilation port 20. This high-temperature air passes through the jet cleaning water that has been sprayed into the cleaning tank 16 by the spray nozzle 19 and diffused in the form of a film. Direct heat exchange without going through an exchanger. That is, the cleaning water is heated by radiating the heat energy of the hot air directly to the jet cleaning water. After the heat is dissipated to the jet cleaning water, the warm air that has become a low temperature air is the second ventilation port.
It is sucked into the blower 23 through the ventilation passage 22 from 21 and is heated again by the heating body 24 to become high-temperature air and is sent into the cleaning tank 16. The arrows and dotted lines shown in the figure indicate the cleaning tank 16 and the ventilation passage 22.
2 shows a warm air circulation path that circulates in a closed circuit formed by.

Next, in the drying step of drying the tableware 15, after the wash water is drained to the outside of the machine, the first ventilation port 26 is opened by the operation of the damper 27, and the ventilation path 22 is communicated with the outside air (see the figure). Solid state). At the same time, the outside air dried by the operation of the blower 23 is sucked into the ventilation passage 22 through the first ventilation port 26, and the heating element is heated.
It is heated by 24 and becomes hot high-temperature air and is blown into the cleaning tank 16. This high-temperature air becomes high-humidity low-temperature air containing steam after evaporating water droplets adhering to the surface of the tableware 15,
Some of them are circulated to the ventilation passage 22 through the first ventilation port 21, and others are exhausted out of the machine through the second ventilation port 28 provided in the lid 29. A part of the high-humidity low-temperature air that has flowed back to the ventilation passage 22 is mixed with dry outside air to reduce the humidity, and then heated again by the heating body 24 to become high-temperature air, which is supplied into the cleaning tank 16 and the above-described operation is repeated. While heating, the tableware 15 is dried. The arrows and dotted lines in the figure show the flow of the intake of the outside air, the circulation of warm air, and the flow of the exhaust.

Here, in the embodiment, the heating body 24 is not particularly limited, but if a positive temperature coefficient thermistor (PTC heater) is used, the blower 23 may become a nest or the ventilation passage 22 may be clogged due to some factor. Even if the ventilation is stopped, as is well known, the heating body 24 composed of a positive temperature coefficient thermistor does not abnormally overheat because the electric resistance increases with a rise in temperature, so that it can be safely used.

Further, FIG. 2 shows a positive temperature coefficient thermistor (PTC heater) as the heating body 24 in the dishwasher according to the embodiment of the present invention.
Fig. 3 shows the characteristics of the heating rate of the washing water when using. As is clear from this figure, the heating for cleaning is smoothly performed and the cleaning can be performed. The power of the PTC heater differs depending on the presence or absence of rated tableware, which is because the air flow rate changes depending on the presence or absence of tableware. It has been confirmed that this cleaning water heating characteristic is almost the same as that of the conventional system using the sheath heater.

EFFECTS OF THE INVENTION As described above, according to the present invention, it is not necessary to use the underwater heater to heat the wash water as in the conventional case, and the heating is performed by the contact between the hot air and the jet wash water. ) 1
The two heating elements can be used for both heating of the washing water and drying of warm air, which simplifies the structure and enables cost reduction.
(2) Since the heating element does not come into direct contact with washing water,
When the dielectric breakdown of the heating element occurs, it is possible to prevent electric leakage to the wash water, resulting in an extremely safe structure. (3) Since there is no heat source in the cleaning tank, heat countermeasures such as providing a heat barrier to the cleaning tank bottom structural member around the heater as in the conventional example having a heater at the cleaning tank bottom and maintaining a spatial distance from the heater It is possible to simplify the structure of the bottom part of the cleaning tank and increase the effective volume of the cleaning tank. In addition, it prevents damage to dishes due to contact with the heater due to falling out of the basket, etc.In addition, when the dishes are washed and dried, the user accidentally touches the high temperature heater with residual heat when removing the dishes from the washing tank. Such an accident can be prevented and great effects can be obtained.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a dishwasher according to an embodiment of the present invention, FIG. 2 is a characteristic diagram showing a washing water heating rate in the dishwasher according to an embodiment of the present invention, and FIG. It is a longitudinal cross-sectional view of a dishwasher. 16 ... Wash tank, 17 ... Wash pump, 18 ... Wash water, 19 ...
… Injection nozzles, 20, 21… Ventilation openings, 22… Ventilation paths, 23…
… Blower, 24 …… Heating body.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaki Yura 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takayuki Ishihara 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 56) References JP-A-58-173527 (JP, A)

Claims (2)

[Claims] 1. A washing tank for storing and washing tableware, an injection nozzle provided in the washing tank, at least two ventilation openings opened in the cleaning tank, and the ventilation openings communicating with each other. An air passage with a partially openable first ventilation port,
A blower and a heating element arranged in this ventilation path, and a second ventilation port that communicates the cleaning tank with the outside are provided. During the cleaning process, the first ventilation port is closed to remove the blower and the heating element. The warm air generated by the operation is circulated through the ventilation passage to heat the wash water, and during the drying process, the first ventilation port is opened and the intake air is taken in while the warm air generated by the operation of the blower and the heating body is heated. A dish washer that blows air into the washing tank through the ventilation passage and exhausts air from the second ventilation port to dry the dishes. 2. The dishwasher according to claim 1, wherein the heating element is formed by a positive temperature coefficient thermistor.