JPH10201608A - Electric rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a blowing fan for cooling a switching element and reduce the noise by controlling an inverter circuit according to the output of a room temperature sensor for detecting the ambient temperature near a regenerative heat skin thermally conductively connected to the switching circuit of the inverter circuit. SOLUTION: When an electric rice cooker is electrified, an inverter circuit 30 is driven through a switching element 31, and a high frequency current is supplied to a heating coil 25, and rice cooking is performed by the heating of an inner pan 24. The heat generated by the switching element 31 is diffused to a regenerative heat skin 32, and the heat not stored when a certain fixed quantity of heat is imparted is released to the air. A support base 40 having an enclose 41 for surrounding a room temperature sensor 50 is mounted near the regenerative heat skin 32. Thus, the heat is stored around the room temperature sensor 40, so that the highest temperature in the second rice cooking never exceeds the breakage temperature of the switching element 31, and the inverter circuit 30 is controlled according to the output of the room temperature sensor 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating type electric rice cooker.

[0002]

2. Description of the Related Art In recent years, with the diversification of consumer preferences, an induction heating type electric rice cooker for cooking more delicious rice has become widespread.

Conventionally, this type of electric rice cooker has an inner pot 2 detachably housed in an electric rice cooker body 1, a heating coil 3 for heating the inner pot 2, as shown in FIG. An inverter circuit 4 for supplying a high-frequency current to the heating coil 3
A switching element 5 of the inverter circuit 4; and a cooling fin 6 provided with the switching element 5 in a thermally conductive manner.
And a printed wiring board 7 on which the inverter circuit 4, the switching element 5, the cooling fins 6 and the like are mounted, and a blower fan 8 for cooling the cooling fins 6 near the printed wiring board 7.

That is, at the time of rice cooking, the switching element 5 drives the inverter circuit 4 to supply a high-frequency current to the heating coil 3 and heat the inner pot 2 to cook rice. In No. 5, since heat is generated during the switching operation, the heat is effectively diffused to the cooling fins 6 and the cooling fins 6 are forcibly blown to the cooling fins 6 by the blower fan 8 for cooling.

[0005]

However, in the above-mentioned conventional electric rice cooker, the rotation sound of the blower fan 8 sounds during cooking, and it has become a new noise source in the kitchen.

Further, a blower fan 8 is provided near the cooling fins 6.
Must be incorporated into the main body, so that the height of the electric rice cooker main body 1 is increased.

An object of the present invention is to solve the above-mentioned conventional problems and to provide an electric rice cooker which eliminates a blower fan and does not generate noise.

It is another object of the present invention to provide a safe electric rice cooker which effectively senses the atmosphere near the regenerative fins, performs normal operations, and is safe.

[0009]

In order to solve the above-mentioned problems, an electric rice cooker according to the present invention comprises an inverter circuit for supplying high-frequency power to a heating coil, and a switching element of the inverter circuit in a thermally conductive manner. A heat storage type heat sink, and a room temperature sensor for detecting an ambient temperature near the heat storage type heat sink, wherein the inverter circuit is controlled in accordance with the output of the room temperature sensor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention employs a heat sink capable of storing heat, so that a switching element can be cooled without a fan, and a temperature sensor of a room temperature sensor detects abnormal temperature rise of the switching element. Thus, the destruction can be prevented.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, the electric rice cooker main body 21 is composed of a body 22 and an upper frame 23. A protection frame 25 for storing the inner pot 24 is provided inside the protection frame 25.
A heating coil 26 and a ferrite 27, which are heating means, are provided below the heater. An operation board 28 is provided on the front of the electric rice cooker main body 21, and an inversion board is provided on the board base 29.
A control board mounted with a heat storage heat sink 32 having a heat transfer circuit 30 and its switching element 31 in good thermal conductivity is mounted. Next, in FIG. 2, a support table 40 is attached near the heat storage type heat sink, and the support table 40 has an enclosure 41 surrounding the sensor.

The operation of the electric rice cooker having the above configuration will be described below. When energization is started, the inverter circuit 30 is driven by the switching element 31 and the heating coil 26 is turned on.
, A high frequency current is supplied to the inner pan 24 to start cooking rice. Then, as in the conventional case, the switching element generates heat. Therefore, this heat is effectively diffused to the heat storage heat sink 32, and when a certain amount of heat is given to the heat storage heat sink 32, the heat that is not stored is released into the air.

Next, how the released heat is used will be described. FIG. 3 shows the heat transfer around the regenerative heat sink, but it moves upward as shown in the figure, and the room temperature sensor 50 has difficulty in detecting the surrounding ambient temperature, and it takes time until the second rice cooking becomes possible. It is also conceivable that the switching element may be damaged during the second rice cooking.

Therefore, by installing a heat sink support as shown in FIG. 4, heat can be stored around the sensor by the heat sink support as shown in FIG. 3, and heat during the second rice cooking can be obtained. The start temperature of the second rice cooking can be reliably detected so that the maximum temperature does not exceed the breakdown temperature of the switching element.

[0016]

As described above, according to the present invention, the noise of the fan motor, which has been a problem in the prior art, can be eliminated, and the heat sink support base provided with the enclosure around the room temperature sensor and the intake / exhaust port are provided. The temperature detection accuracy of the room temperature sensor was surely improved by providing, and failure of the electric rice cooker in continuous rice cooking could be prevented.

[Brief description of the drawings]

FIG. 1 is a cutaway sectional view of an electric rice cooker according to one embodiment of the present invention.

FIG. 2 is a detailed view of a main part near a heat sink of the electric rice cooker.

FIG. 3 is a cross-sectional view of a main part near a heat sink of the electric rice cooker.

FIG. 4 is a plan view of a main part of a heat sink support stand of the electric rice cooker.

FIG. 5 is a cutaway sectional view of a conventional electric rice cooker.

[Explanation of symbols]

 Reference Signs List 30 inverter circuit 31 switching element 32 heat sink

Continuing from the front page (72) Inventor Shinichi Sato 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Jika Arisu 1006 Kazuma Kadoma, Kadoma City Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] An inverter circuit for supplying high-frequency power to a heating coil, a heat storage heat sink joined to a switching element of the inverter circuit in a thermally conductive manner, and an ambient temperature near the heat storage heat sink. An electric rice cooker comprising: a room temperature sensor for detecting, wherein the inverter circuit is controlled in accordance with an output of the room temperature sensor. 2. The electric rice cooker according to claim 1, wherein the room temperature sensor is provided with an enclosure around the room temperature sensor. 3. A printed wiring board having a heat storage type heat sink mounted thereon, wherein the heat storage type heat sink is arranged below the printed wiring board, and a room temperature sensor is arranged above the heat sink. The electric rice cooker according to claim 1 or 2, wherein 4. The electric rice cooker according to claim 3, wherein an exhaust port is provided in a main body near a lower portion and an upper portion of a position where the printed wiring board is provided.