JP2000058246A - Induction heating applied cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce induction heating caused by leaked magnetic flux on the placing surface of an induction heating applied cooker by arranging a ring- shaped non-magnetic metal plate under an induction heating coil. SOLUTION: This induction heating applied cooking device has a load 6 and an induction heating coil 8 connected to a high frequency inverter 7, and the load 6 is heated with a high frequency magnetic field generated with the induction heating coil 8. A ring-shaped non-magnetic metal plate 9 is arranged under the induction heating coil 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking device using induction heating.

[0002]

2. Description of the Related Art In an induction heating cooker, a high-frequency magnetic field is generated from an induction heating coil, and a load is heated due to an eddy current caused by electromagnetic induction.

[0003] In recent years, high value-added induction cooking appliances have been developed, and the size of the housing tends to increase. However, in the market, there is an increasing demand for downsizing of the housing due to problems such as a mounting space.

A conventional induction heating type rice cooker will be described below with reference to FIG. In the figure, 1 is a rice cooker,
2 is a high-frequency inverter, 3 is connected to the high-frequency inverter 2, and is an induction heating coil arranged at the bottom of the rice cooker 1, 4 is a housing, and 5 is a rice cooker mounting surface.

As shown in this configuration, a high-frequency magnetic field is generated from the induction heating coil 3 by the high-frequency current supplied by the high-frequency inverter 2, and the rice cooker 1 is heated by an eddy current due to electromagnetic induction.

[0006]

In the above-described conventional configuration, the distance between the induction heating coil 3 and the rice cooker mounting surface 5 becomes short especially when the size of the housing 4 is reduced.
When the material of the rice cooker mounting surface 5 is metal, the rice cooker mounting surface 5 may be heated by induction heating due to magnetic flux leakage from the induction heating coil 3, which may cause a problem in use. Was done.

Accordingly, the present invention solves the above-mentioned conventional problems, in which a ring-shaped non-magnetic metal plate is arranged below the induction heating coil to perform induction heating of the mounting surface by leakage magnetic flux from the induction heating coil. An object of the present invention is to provide an induction heating cooker that can reduce the size and reduce the size of the housing.

[0008]

In order to solve the above-mentioned problems, the present invention provides a high-frequency inverter, an induction heating coil connected to the high-frequency inverter, and induction heating by a high-frequency magnetic field generated from the induction heating coil. A load, and an induction heating cooker or the like in which a ring-shaped non-magnetic metal plate is arranged below the induction heating coil.

[0009]

The invention according to claim 1 has a high-frequency inverter, an induction heating coil connected to the high-frequency inverter, and a load that is induction-heated by a high-frequency magnetic field generated from the induction heating coil. By using an induction heating cooker in which a ring-shaped non-magnetic metal plate is disposed below the induction heating coil, electromagnetic flux leakage from the induction heating coil is electromagnetically shielded, so that induction heating of the mounting surface is performed. Can be reduced. Therefore, it is possible to provide an induction heating application cooker in which the size of the housing can be reduced.

According to the second aspect of the present invention, in particular, by setting the thickness of the ring-shaped non-magnetic metal plate to be equal to or greater than the skin depth, the magnetic flux leakage from the induction heating coil can be effectively shielded.

[0013] The invention according to claim 3 is that the ring-shaped non-magnetic metal plate is arranged at the lowermost portion in the housing.
Heat generation due to induction heating of the ring-shaped non-magnetic metal plate itself can be minimized.

The invention according to claim 4 is that the ring-shaped non-magnetic metal plate has the same size as or larger than the outermost diameter of the induction heating coil facing the induction heating application cooking device mounting surface. Since the ring-shaped non-magnetic metal plate has a predetermined size suitable for electromagnetically shielding magnetic flux leakage from the induction heating coil, shielding efficiency with respect to cost can be increased. Further, the housing only needs to have a minimum capacity in which the non-magnetic metal plate can be arranged.

According to a fifth aspect of the present invention, one or a plurality of circuit components of the high-frequency inverter are closely attached to the ring-shaped non-magnetic metal plate, thereby increasing the heat radiation efficiency of the high-frequency inverter circuit components. Can do
It is possible to reduce the rotation of the fan, to reduce the size, or to abolish the fan.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) A first embodiment of the present invention will be described below using an induction heating rice cooker as an example.

An embodiment of the first means will be described with reference to the drawings. In FIG. 1, 6 is a rice cooker, 7 is a high frequency inverter, 8 is an induction heating coil connected to the high frequency inverter 7 and arranged at the bottom of the rice cooker 6, 9
Is a non-magnetic metal plate disposed below the induction heating coil 8, and 10 is a housing. In addition, 11 is a rice cooker mounting surface.

A high-frequency magnetic field is generated from the induction heating coil 8 by the high-frequency current supplied by the high-frequency inverter 7, and the rice cooker 6 is heated by an eddy current due to electromagnetic induction. At this time, the magnetic flux leaking from the induction heating coil 8 is electromagnetically shielded by the nonmagnetic metal plate 9, and the magnetic flux leaking to the rice cooker mounting surface 11 is reduced. As a result, even when the rice cooker mounting surface 11 is made of a metal, it is possible to provide an induction heating cooker in which the housing 10 can be miniaturized with little induction heating. .

(Embodiment 2) Next, a second embodiment of the present invention will be described with reference to the drawings. In FIG. 2, 1
2 is a rice cooker, 13 is a high-frequency inverter, 14 is an induction heating coil connected to the high-frequency inverter 13 and arranged at the bottom of the rice cooker 12, and 15 is the induction heating coil 1.
4, a non-magnetic metal plate 16 arranged at the lower part is constituted by a housing. In addition, 17 is a rice cooker mounting surface.

The thickness of the non-magnetic metal plate 15 is not less than the skin depth. In the present embodiment configured as described above, by making the thickness of the non-magnetic metal plate 15 equal to or greater than the skin depth, electromagnetic shielding can be effectively performed without passing magnetic flux leakage from the induction heating coil 14. Can be done.

Embodiment 3 Next, a third embodiment of the present invention will be described with reference to the drawings. In FIG. 3, 1
8 is a rice cooker, 19 is a high-frequency inverter, 20 is an induction heating coil connected to the high-frequency inverter 19 and arranged at the bottom of the rice cooker 18, 21 is the induction heating coil 2.
A non-magnetic metal plate disposed at the lower part of the device 0, a housing 22 and a fan 23. In addition, 24 is a rice cooker mounting surface.

The non-magnetic metal plate 21 is arranged at the lowermost part in the housing 22. In the present embodiment configured as above, by increasing the distance between the nonmagnetic metal plate 21 and the induction heating coil 20 as much as possible, the eddy current loss generated in the nonmagnetic metal plate 21 itself is minimized. It can be. Therefore, it is possible to suppress an increase in the ambient temperature inside the housing 22, which is effective for downsizing the fan 23, reducing noise by lowering the rotation speed, and further downsizing the housing 22.

(Embodiment 4) Next, a fourth embodiment of the present invention will be described with reference to the drawings. In FIG. 4, 2
5 is a rice cooker, 26 is a high-frequency inverter, 27 is an induction heating coil connected to the high-frequency inverter 26 and arranged at the bottom of the rice cooker 25, 28 is the induction heating coil 2
The non-magnetic metal plate 29 arranged at the lower part of 7 is constituted by a housing. In addition, 30 is a rice cooker mounting surface.

The nonmagnetic metal plate 28 has the same size as or larger than the outermost diameter of the induction heating coil 27 facing the rice cooker mounting surface 30. In the present embodiment thus configured, the nonmagnetic metal plate 28
Is a predetermined size suitable for electromagnetically shielding magnetic flux leakage from the induction heating coil 27, so that shielding efficiency with respect to cost can be improved. The housing 29
May be a minimum capacity in which the non-magnetic metal plate 28 can be arranged.

(Embodiment 5) Next, a fifth embodiment of the present invention will be described with reference to the drawings. In FIG. 5, 3
1 is a rice cooker, 32 is a high-frequency inverter, 33 is an induction heating coil connected to the high-frequency inverter 32 and arranged at the bottom of the rice cooker 31, 34 is the induction heating coil 3.
3, a non-magnetic metal plate disposed at a lower portion, a housing 35, and a fan 36. In addition, 37 is a rice cooker mounting surface.

Any one of the high-frequency inverters 32 or a plurality of circuit components is closely attached to the non-magnetic metal plate 34.

In this embodiment configured as described above,
The non-magnetic metal plate 34 also has the effect of increasing the heat radiation efficiency of the circuit components of the high-frequency inverter 32, so that the rotation of the fan 36 can be reduced, downsized, or eliminated, and the noise can be reduced. Can be further reduced in size.

[0026]

As described above, according to the present invention, according to the first aspect of the present invention, a ring-shaped non-magnetic metal plate is disposed below the induction heating coil, and the leakage magnetic flux from the induction heating coil is reduced. By performing electromagnetic shielding, induction heating of the mounting surface can be reduced. Therefore, it is possible to provide an induction heating application cooker in which the size of the housing can be reduced.

According to the second aspect of the present invention, in particular, the thickness of the ring-shaped non-magnetic metal plate is set to be equal to or greater than the skin depth, and the electromagnetic flux from the induction heating coil is effectively shielded. Can be done.

According to the third aspect of the present invention, the ring-shaped non-magnetic metal plate is particularly arranged at the lowermost portion in the housing. Can be minimized.

According to the fourth aspect of the present invention, the ring-shaped non-magnetic metal plate is particularly equal to or larger than the outermost diameter of the induction heating coil facing the induction heating application cooker mounting surface. Because it is a predetermined size suitable for electromagnetically shielding magnetic flux leakage from the induction heating coil,
The shielding efficiency with respect to cost can be increased. Also,
The housing only needs to have the minimum capacity in which the nonmagnetic metal plate can be arranged.

According to the fifth aspect of the present invention, one of the high-frequency inverters is provided on the ring-shaped non-magnetic metal plate.
Or with multiple circuit components closely attached,
The heat radiation efficiency of the high-frequency inverter circuit components can be increased, and the fan can be reduced in speed and reduced in size, or the fan can be eliminated to reduce noise and further reduce the size of the housing.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of an induction heating rice cooker according to a second embodiment of the present invention.

FIG. 3 is a sectional view of an induction heating rice cooker according to a third embodiment of the present invention.

FIG. 4 is a sectional view of an induction heating rice cooker according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view of an induction heating rice cooker according to a fifth embodiment of the present invention.

FIG. 6 is a sectional view of a conventional induction heating type rice cooker.

[Explanation of symbols]

 1, 6, 12, 18, 25, 31 Rice cooker 2, 7, 13, 19, 26, 32 High frequency inverter 3, 8, 14, 20, 27, 33 Induction heating coil 4, 10, 16, 22, 29, 35 case 5, 11, 17, 24, 30, 37 mounting surface 9, 15, 21, 28, 34 ring-shaped non-magnetic metal plate 23, 36 fan

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hidekazu Yamashita 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 3K051 AA02 AA08 AB04 AB05 AB10 AB13 AC10 AC42 AD03 AD27 AD32 AD37 CD42 CD43 CD44

Claims (5)

[Claims] A high-frequency inverter, an induction heating coil connected to the high-frequency inverter, and a load induction-heated by a high-frequency magnetic field generated from the induction heating coil; Induction heating cooker with a non-magnetic metal plate. 2. The induction heating cooker according to claim 1, wherein the thickness of the ring-shaped nonmagnetic metal plate is equal to or greater than the skin depth. 3. The induction heating cooker according to claim 1, wherein the ring-shaped non-magnetic metal plate is disposed at a lowermost portion in the housing. 4. The induction heating application cooking according to claim 1, wherein the ring-shaped non-magnetic metal plate has a size equal to or larger than the outermost diameter of the induction heating coil facing the induction heating application cooking device mounting surface. vessel. 5. The induction heating cooker according to claim 1, wherein one or a plurality of circuit components of the high-frequency inverter is closely attached to the ring-shaped non-magnetic metal plate to enhance heat radiation efficiency.