JPH0751158A - Induction heating rice cooker - Google Patents

Abstract

PURPOSE:To provide the induction heating rice cooker by which it is not necessary to use an air blowing fan for cooling by improving the cooling effect of a radiation fin at an inverter circuit device. CONSTITUTION:Concerning the induction heating rice cooker for cooking rice by performing the induction heating of an inner pot 5 housed inside a protection frame 2 of a main body 1 with a high frequency magnetic field generated from an induction heating coil 3 connected to an inverter circuit device 4, a suction hole 8 is formed in the lower direction of the main body 1, an exhaust hole 9 is formed in the upper direction of the main body 1, and a radiation fin 10 of the inverter circuit device 4 is formed at a certain position higher than the suction hole 8 in the lower direction of the main body 1 and lower than the exhaust hole 9. The radiation fin 10 is arranged in the flowing passage of air between the suction hole 8 and the exhaust hole 9 for raising air heated by the induction heating coil 3, the inverter circuit device 4 or the protection frame 2 to get high temperature during rice cooking, for exhausting the air from the exhaust hole 9 and for sucking external air from the suction hole 8 in place of the heated air, and the radiation fin 10 is cooled by naturally circulating air inside the main body 1.

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 rice cooker having a cooling means for high temperature parts of an inverter circuit device for generating a high frequency magnetic field in an induction heating coil.

[0002]

2. Description of the Related Art Japanese Patent Publication No. 63-5875 and Japanese Patent Laid-Open No. 62-17985 disclose an induction heating type cooker of this type having a cooling means for a high temperature component of a conventional inverter circuit device.
Japanese Laid-Open Patent Publication No. 1-276585 and Japanese Laid-Open Patent Publication No. 4-17 are examples of induction heating rice cookers.
Japanese Patent No. 0917 is known. However, these are all inventions for forcibly cooling the inverter circuit device with a blower fan and forcibly blowing air to cool the inverter circuit device.

FIG. 2 shows a configuration example of an induction heating type rice cooker having a conventional cooling means. A protective frame 2 forming an inner wall of the main body 1 is attached, and an induction heating coil 3 is attached to a bottom surface of the protective frame 2. An inverter circuit device 4 is attached to the lower inside of the main body 1, and the inverter circuit device 4 is electrically connected to the induction heating coil 3. An inner hook 5 is detachably inserted into the protective frame 2 and held therein. A temperature sensor 6 for obtaining temperature information is attached to the bottom of the protective frame 2, and abuts on the bottom of the inner pot 5 to be thermally coupled.

An intake hole 18 in which a plurality of lattice-shaped holes are combined is provided at the bottom of the main body 1 or at a lower portion of the side surface, and similarly, at a lower portion of the main body 1 or at a lower portion of the side surface, for example, the intake hole
Exhaust hole 1 in which a plurality of grid-like holes are combined diagonally
9 is provided. The inverter circuit device 4 is provided with radiating fins 10 for cooling high temperature parts, and is arranged above the intake holes 18. Intake hole 18 and exhaust hole 19
Since there is almost no difference in height and natural convection does not occur, a blower fan 11 and an electric motor 12 are provided above the intake hole 18 of the inverter circuit device 4 in order to forcibly cool the radiation fin 10.

[0005]

All of the above conventional structures require a blower fan and a motor for forced cooling. In particular, the former induction heating type cooker, that is, the electromagnetic cooker uses an unspecified pot and the power and time used depending on the cooking menu are different, so even under various conditions,
In order to prevent abnormal heating of the inverter circuit device, it was necessary to allow sufficient cooling performance, and forced cooling with a blower fan was essential. Also, in the latter induction heating type rice cooker, the electric motor 12 is required to rotate the blower fan 11, there are many parts, the number of assembling steps is large, the cost is high, and the main body 1 must be large. there were. Further, in the rice cooker, it is common to use rice for a timer reservation before getting up in the early morning, and there is a problem that the wind noise caused by the blower fan 11 becomes annoying and awakens.

[0006] In a rice cooker, as the rice cooking process progresses, the power to be supplied is appropriately changed according to the rice cooking capacity at that time, and the heating control is generally performed as in "beginning choro choro papa ...". However, it can be controlled by the rice cooker side without changing it according to the user's intention, and in the induction heating rice cooker, the conditions such as the pan, cooking menu, power input, and time are specified within a very narrow range. Therefore, the present invention is limited to the induction heating type rice cooker, and the blowing fan and the electric motor are eliminated, and it is an object of the present invention to sufficiently cool the high temperature components of the inverter circuit device.

[0007]

The present invention has been made to solve the above-mentioned problems, and is housed in a protective frame of a main body by a high frequency magnetic field generated from an induction heating coil connected to an inverter circuit device. In an induction heating type rice cooker that induction-heats and cooks rice in an inner pot, an intake hole is provided at the bottom of the main body or at the bottom of the main body, and an exhaust hole is provided at the top of the main body or above the side of the main body. The heat dissipation fins of the inverter circuit device are installed in a low position, and the air heated by the induction heating coil, the inverter circuit device and the protective frame that become hot during rice rises and is exhausted from the exhaust hole, and the outside air is taken in instead. Radiating fins are placed in the air flow path between the intake and exhaust holes that are sucked in through the holes, and the radiator fins are cooled by natural convection of air inside the body. It was.

[0008]

According to the structure of the present invention, the air heated by the induction heating coil, the inverter circuit device and the protective frame, which become high in temperature during rice cooking, rises and is discharged from the exhaust hole, and the substitute outside air is discharged from the intake hole. A flow of inhaled air occurs.
Further, the air around the radiation fins is also heated by the radiation fins and rises, so that air flows due to natural convection inside the main body from the lower side to the upper side. The radiating fins of the inverter circuit device arranged in the air flow path between the air intake hole and the air exhaust hole inside the main body are cooled by this air flow.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a sectional view of an induction heating type rice cooker to which an embodiment of the present invention is applied.

In FIG. 1, a main body 1 is provided with a protective frame 2 forming its inner wall, and an induction heating coil 3 is attached to the bottom surface of the protective frame 2. An inverter circuit device 4 is attached to the lower inside of the main body 1, and the inverter circuit device 4 is electrically connected to the induction heating coil 3.

An inner hook 5 is detachably inserted into the protective frame 2 and held therein. A temperature sensor 6 for obtaining temperature information is attached to the bottom of the protective frame 2, and abuts on the bottom of the inner pot 5 to be thermally coupled. A control unit 7 is provided inside the main body 1, and the inverter circuit device 4 is provided in the control unit 7.
And the temperature sensor 6 are connected.

An intake hole 8 having a plurality of lattice-shaped holes combined therein is provided at the bottom of the body 1, and an exhaust hole 9 having a plurality of lattice-like holes similarly combined is provided above the side surface behind the body 1. It is provided. The inverter circuit device 4 is provided with radiating fins 10 for cooling high temperature parts, and is arranged below the exhaust holes 9.

The operation of this embodiment having the above structure will be described below.

The user puts the washed rice and an appropriate amount of water in the inner pot 5 and inserts it into the protective frame 2. Next, when a rice cooking switch (not shown) is operated, the rice cooking operation is started by the operation of the control unit 7. For cooking rice, "the beginning chopped choppa ..."
According to the legend, it is necessary to adjust the fire as it progresses. When rice cooking is started by the operation of the user, the inverter circuit device 4 operates according to the temperature information of the temperature sensor 6 and the heating control program provided in advance in the control unit 7, and the high frequency magnetic field generated from the induction heating coil 3 is generated. It changes and the heat generation of the inner pot 5 changes. Along with this, a part of the components of the inverter circuit device 4, for example, the switching element or the like becomes hot.

Since these components cause a failure when the temperature exceeds a certain temperature, it is necessary to keep the temperature below the certain temperature. Therefore, these components are mounted so as to be thermally coupled to the radiation fin 10. Therefore, the heat of the components is transmitted to the radiation fins 10, and when the ambient temperature is reached, the heat is radiated to the surrounding air. The heated air becomes lighter and rises, creating natural convection that draws in fresh cool air from below.

The air flow is small only by natural convection, but the inner pot 5 becomes hot during the rice cooking operation, and the induction heating coil 3 and the protective frame 2 also receive radiant heat and become hot.
The internal air warms and rises. The rising air is the main body 1
Since it is discharged from the exhaust hole 9 provided on the upper side surface, it does not stay inside the main body 1, and instead, cold outside air is drawn into the main body 1 from the air hole 8 at the bottom of the main body 1. That is, since an air flow is generated from the lower side to the upper side, the air around the radiating fins 10 arranged between the flow paths actively flows, and the heat of the radiating fins 10 can be efficiently removed.

In the induction heating type rice cooker having the conventional structure, as described above, there is almost no difference in height between the intake hole and the exhaust hole, and efficient cooling cannot be achieved without forced convection cooling. According to the configuration of the present invention, as described above, the air flow is generated in the main body 1 from the lower side to the upper side, so that the cooling performance can be obtained without the blowing fan. However, the cooling performance itself is higher with the forced cooling method using a blower fan because of the amount of air flow. However, in the rice cooker, since the time and the electric power supplied are almost constant for the purpose, the amount of heat radiation required by the radiation fin 10 is also limited. Radiation fin 1
Although 0 determines the amount of heat dissipation by its surface area, the surface area is determined so as to sufficiently secure the above required amount of heat dissipation.

Further, even when the cooked rice is used for purposes other than the original cooked rice, such as boiling water due to misuse by the user, when the time required for cooked rice elapses, the power is reduced by the program of the control unit 7 and the inverter circuit device 4 If there is no abnormal heating, there will be no problem.

In the present invention, the intake hole 8 and the exhaust hole 9
The positional relationship between the heat radiating fins 10 and the heat radiating fins 10 is not limited to the above, and the intake holes 8 may be provided at the bottom of the main body 1 or below the side surfaces of the main body 1, and the exhaust holes 9 may be provided at the top surface of the main body or above the side surfaces of the main body 1. 8 forms a flow path of air from the upper side to the exhaust hole 9, and the radiating fin 1 is provided between the flow paths of air.
If 0 is provided, the same function and effect as those of the above-mentioned embodiment can be obtained.

[0020]

As described above, according to the present invention, the intake hole is provided below the main body, the exhaust hole is provided above the main body, and the radiation fin of the inverter circuit device is provided in the space between the intake hole and the exhaust hole inside the main body. , A smooth natural air flow is generated from the lower part of the main body to the upper part, and efficient cooling can be achieved. This eliminates the need for forced cooling with a blower fan, and eliminates the need for a blower fan and an electric motor, which reduces the number of components, reduces the weight, and reduces the number of assembly steps, thus providing consumers with an inexpensive induction heating rice cooker. . Moreover, since there is no wind noise of the blower fan, problems such as waking up with sound even if rice is cooked with a timer reservation can be solved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an induction heating type rice cooker according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional induction heating rice cooker.

[Explanation of symbols]

 1 Main body 2 Protective frame 3 Induction heating coil 4 Inverter circuit device 5 Inner pot 8 Intake hole 9 Exhaust hole 10 Radiating fin

Claims (2)

[Claims] 1. A high frequency magnetic field generated from an induction heating coil (3) connected to an inverter circuit device (4) induces an inner pot (5) housed in a protective frame (2) of a main body (1). In an induction heating type rice cooker that heats and cooks rice, an intake hole (8) is provided below the main body (1), and the main body (1) is provided.
An exhaust hole (9) is provided above, and a heat dissipation fin (10) of the inverter circuit device (4) is provided at a position higher than the intake hole (8) inside the body (1) and lower than the exhaust hole (9). ) Radiating fins (1
An induction heating type rice cooker characterized in that 0) is cooled. 2. The air heated by the induction heating coil (3), the inverter circuit device (4) and the protective frame (2), which become hot during rice cooking, rises and is discharged from the exhaust hole (9), The induction heating type rice cooker according to claim 1, wherein the heat radiation fins (10) are arranged in a flow path of air between an intake hole (8) and an exhaust hole (9) through which the outside air is sucked in instead of outside air. vessel.