JP2003151746A - Induction heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a light emitter and a temperature sensor from being influenced by magnetic flux generated by a high frequency current flowing in a heating coil. SOLUTION: This induction heating cooker comprises the heating coils 13 for induction-heating an object 7, magnetic bodies 14 for preventing leakage of magnetic flux from the heating coil 13, and a light emitter device 15 for displaying a graphic on a top plate 2 by light. The magnetic bodies 14 are vertically fixed on at least one of inner or outer peripheries of the heating coils 13 for supporting a lower part of the heating coils 13 and thereby the magnetic bodies 14 are interposed between the emitter device 15 and the heating coils 13. Accordingly, it is prevented that an emission means is influenced by the leakage magnetic flux.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating cooker, and more particularly to a temperature sensor for measuring the temperature of a light emitter or a top plate which illuminates the top plate.

[0002]

2. Description of the Related Art Heretofore, as an induction heating cooker of this type, there has been one described in Japanese Patent Application Laid-Open No. 2001-160483. FIG. 5 shows a sectional view of the conventional induction heating cooker described in the above publication.

In FIG. 5, reference numeral 101 denotes a main body forming an outer shell of an induction heating cooker, reference numeral 102 denotes a top plate placed on the upper portion of the main body 101, and an object 103 to be heated such as a pot placed on the top plate. Placed. Reference numeral 104 denotes a heating coil provided below the top plate 102 for inductively heating the object 103 to be heated. Reference numeral 105 denotes a light emitting body provided below the heating coil 105, and the light source 1 provided at the center thereof.
06, and a light guide body 107 that inputs and guides the light and radiates the light toward the top plate 102 from the end portion thereof. Reference numeral 108 denotes a temperature sensor that contacts the lower surface of the top plate 102 and indirectly measures the temperature of the object 103 to be heated. Further, 109 is an operation unit (not shown)
And a control unit that controls the heating coil 104, the light source 106, and the like based on signals from the temperature sensor 108 and the like. FIG. 6 is a perspective view of the light emitter 105. The light emitter 1 includes a fan-shaped light guide piece 107a and a fan-shaped light source 106.
One block of No. 05 is combined, and these blocks are combined to form an annular light guide.

In the above structure, when the power is turned on, a high-frequency current flows through the heating coil to heat the object 103 to be heated, the light source 6 is turned on, and the outer peripheral light emitting surface 107b of the annular light guide body emits light. The heating area of the heating coil 104 is clearly defined by drawing an annular pattern on the top plate 102 by the light. As a result, the object 103 to be heated can be placed in the correct position. Further, the temperature sensor 108 detects the temperature of the object 103 to be heated and controls the output of the heating coil, so that cooking can be appropriately performed.

[0005]

However, in the above-mentioned conventional structure, when the object 103 to be heated is heated by passing a high frequency current of 20 to 30 kHz like an iron pan, the magnetic field generated causes the luminous body 105 and the temperature to rise. Since it was relatively easy to prevent the sensor 108 from being affected by the leakage magnetic flux, it did not pose a problem. However, when heating a copper pan or an aluminum pan having a low magnetic permeability, it is 40 to 100.
A high-frequency current of kHz has to be passed through the heating coil 104, and the magnetic field generated at this time has a problem that the light emitting body 105 and the temperature sensor 108 are affected by the leakage magnetic flux and cannot perform stable light emission or detection. At high frequencies no light emitters or temperature sensors were used.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide an induction heating cooker in which the light emitter and the temperature sensor are less susceptible to the influence of the high-frequency current flowing in the heating coil.

[0007]

In order to solve the conventional problems, the induction heating cooker of the present invention has a structure in which a magnetic material is interposed between the heating coil and the light emitting means. With this configuration, the light emitting means can be made less susceptible to the influence of the magnetic flux generated when a high frequency current is passed through the heating coil.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is characterized in that a main body forming an outer shell, a top plate on which an object to be heated, which is provided on an upper surface of the main body, is placed, and the top plate is provided below the top plate. A heating coil for inductively heating an object to be heated, a magnetic body for preventing leakage of magnetic flux from the heating coil, and a light emitting means for displaying a graphic on the top plate by light, the light emitting means and the heating coil A magnetic material is interposed between the two. With this configuration, it is possible to prevent the magnetic flux generated when a high-frequency current is passed through the heating coil from leaking toward the light emitting means. Therefore, a stable figure can be displayed on the top plate.

The invention as defined in claim 2 is particularly characterized by claim 1.
In the configuration described in (3), the temperature sensor is less susceptible to the leakage magnetic flux and the stable temperature can be obtained because the magnetic substance is interposed between the temperature detecting means for detecting the temperature of the object to be heated or the top plate and the heating coil. It can detect.

The invention as defined in claim 3 is particularly defined by claim 1.
Alternatively, in the configuration according to 2, the magnetic body is vertically provided on at least one of the inner and outer circumferences of the heating coil and supports the lower side of the heating coil.
The magnetic flux can be prevented from leaking to the side surface and the lower side of the heating coil, and the light emitting means, the temperature sensor, or the electronic component can be stably operated.

The invention as defined in claim 4 is particularly characterized by claim 1.
In the configuration according to any one of 1 to 3, a high-frequency current not lower than 40 kHz is applied to the heating coil to induction-heat the object to be heated, and thus a copper pot or an aluminum pot with low magnetic permeability is used. Even when heated by heating, a light emitting means or a temperature sensor can be used.

[0012]

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

(Embodiment 1) FIG. 1 is a sectional view of an essential part of an induction heating cooker according to a first embodiment of the present invention, and FIG. 2 is an external perspective view of the induction heating cooker. In addition, as an example of an induction heating cooker using the configuration of the heating coil portion of the present invention, 3
A description will be given of an induction heating cooker having a heating part at a location, a so-called three-port stove part.

In FIG. 2, a top plate 2 is provided on the upper surface of the induction heating cooker body 1. The top plate 2 is provided with induction heating units 3a and 3b that heat a pan by induction heating to heat an object to be cooked, and a radiant heater unit 4 that cooks using a pan that cannot be used in induction heating. Further, a roasting device 5 and an operating portion 6 are provided on the front side surface of the main body 1 which constitutes the outer shell of the induction heating cooker.
In the present invention, the heating coil unit of the present invention is used for at least one of the induction heating units 3a and 3b.

In FIG. 1, the object 7 to be heated is placed on one of the induction heating units 3a and 3b on the top plate 2 to which the structure of the present invention is applied. And
A heating coil portion 8 is provided below the top plate 2 corresponding to the heated portion 7. The heating coil unit 8 includes a heating coil device 9, an elastic body 11 provided on a holding plate 10 for supporting the heating coil device 9, and a buffer body 12 provided between the elastic body 11 and the top plate 2. It is composed by. Further, the heating coil device 9 has a built-in heating coil 13 that performs induction heating and a magnetic body 14 that supports the heating coil 13 and prevents leakage of magnetic flux. Further, around the magnetic body 14, there is provided a light emitting device 15 which is a light emitting means for irradiating light and drawing a figure by the light on the top plate 2. This light emitter device 15 is a substrate provided below a light emitter 16 such as a light bulb or a light emitting diode (LED), a light guide plate 17 for guiding light and a light emitter, and a magnetic body 14 for holding the light guide and wiring. It is composed of 18 and.

In the above structure, the elastic body 11 is made of a springy elastic body, and the heating coil device 9 is formed by the biasing force of the spring.
Is pressed against the lower part of the top plate 2. At this time,
A shock absorber 12 made of rubber or the like is provided between the top plate 2 and the elastic body 11 to make it difficult for vibrations generated when a high frequency current is passed through the heating coil to be transmitted to the top plate 2. In addition, there are methods of fixing the heating coil device 9 and the top plate 2 such as fixing with an adhesive or fixing with an external force. In either case, vibration is easily transmitted to the top plate 2. You need to be careful.

By fixing the heating coil device 9 to the top plate 2 in this manner, the distance between the heating coil 13 and the object 7 to be heated can be kept constant, and the magnetic flux generated in the heating coil 13 can be efficiently used. It can be put in the object to be heated 7 well.

Next, the relationship between the heating coil 13 and the magnetic body 14 will be described with reference to the perspective view of FIG. As shown in FIG. 3, the magnetic body 14 is configured such that a portion vertically provided on the inner circumference and the outer circumference of the heating coil 13 and a portion provided below the heating coil are integrally formed to hold and fix the heating coil 13. ing. With this configuration, it is possible to prevent the magnetic flux from leaking downward or to the side, it is possible to prevent adverse effects on the electronic components provided in the operation unit 6, and it is possible to efficiently heat the object 7 to be heated. In this embodiment, the magnetic substance 1
Although a part of 4 is erected vertically on the inner and outer circumferences of the coil, the invention is not limited to this, and the leakage prevention effect is slightly reduced, but either one of the inner and outer circumferences may be provided. In particular, when the luminous body device 15 is used as in this embodiment, a magnetic body must be provided between the heating coil 13 and the luminous body device 15 in order to prevent the luminous body device 15 from being affected by the leakage magnetic flux. There is. Further, ferrite is generally used as the magnetic body, and the magnetic body is fixed to the heating coil device 9 with an adhesive, or is attached by heat fusion during molding.

The light emitting device 15 is designed so that a user can easily recognize the position of the heating coil by drawing a graphic on the top plate 2 by the light emitted from the light guide plate. This allows the user to put the object to be heated in an appropriate position. Since the light emitting means is used for such a purpose, the light emitting means is not limited to the configuration of this embodiment, and the light guide body pieces as shown in FIG. It may be a light-emitting device that emits light, or light from a light source may be introduced into a part of an annular tube and irradiated toward the top plate.

With respect to the induction heating cooker configured as described above, its function and effect will be described below.

When the power is turned on and a high-frequency current flows through the heating coil 13, magnetic flux enters the object to be heated 7 and the object to be heated 7 is heated. At this time, since the heating coil 13 has a substantially constant distance from the object to be heated 7 due to the elastic body 11, a substantially constant amount of magnetic flux always enters the object to be heated 7 and is efficiently heated. Further, the magnetic material 1 is formed on the side surface and the bottom surface of the heating coil 13.
Since 4 is provided, it is possible to reduce the leakage of magnetic flux to the lower side and the side surface, improve heating efficiency, and prevent adverse effects on electronic components.

The light-emitting body 16 is turned on, the light is guided through the light guide plate 17, and the top plate 2 is irradiated with light from the upper surface thereof to draw a pattern on the top plate. This makes the position of the heating coil 13 clear. At this time,
Since the magnetic body 14 is provided between the light emitting body 16 and the light guide plate 17 and the heating coil 13, the light emitting body 16 and the light guide plate 17 are hardly affected by the leakage magnetic flux and can emit stable light. it can.

Such an effect is obtained by heating a copper pan or an aluminum pan having a low magnetic permeability for 40 to 100 k.
It becomes particularly noticeable when a high frequency current of Hz is passed.

Note that the gist of the present invention is to provide a magnetic material between the heating coil and the light emitting means so that the magnetic flux generated when a high frequency current is passed through the heating coil does not leak and adversely affect the light emitting means. It is intended for that purpose, and it goes without saying that the structure is not limited to the above-mentioned structure as long as the structure satisfies this purpose.

(Embodiment 2) FIG. 3 is a sectional view of an essential part of an induction heating cooker according to Embodiment 2 of the present invention. Since the basic configuration of this embodiment is similar to that of the first embodiment, the description thereof will be omitted and the different points will be mainly described. Moreover, the same reference numerals are given to the same configurations, and the description thereof will be omitted.

In FIG. 4, a temperature sensor device 19 as a temperature detecting means is provided at the center of the heating coil 13. The temperature sensor device 19 includes a temperature sensor 20 and a pressure contact spring 21, and the temperature sensor 20 contacts the top plate 2 by the urging force of the pressure contact spring 21. At this time, the temperature sensor device 19 and the heating coil 13
A magnetic body 14 is provided between That is, the portion of the magnetic body 14 provided vertically from the bottom is interposed between the temperature sensor device 19 and the heating coil 13. As a result, the temperature sensor 20 can accurately detect the temperature of the object to be heated with almost no influence of the leakage magnetic flux.

Such an effect is obtained by heating a copper pan or an aluminum pan having a low magnetic permeability by 40 to 100 k.
It becomes particularly noticeable when a high frequency current of Hz is passed.

Further, as in the first embodiment, the temperature detecting means is not limited to the above-mentioned configuration, and it goes without saying that another configuration may be adopted as long as it is a configuration that complies with the gist of the present invention.

In addition, although the induction heating cooker having the three stove sections has been described in the first and second embodiments, the number of the stove sections is not limited to this.

[0030]

As described above, according to the present invention, the light emitter and the temperature sensor can be made less susceptible to the influence of the high frequency current flowing through the heating coil.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an induction heating cooker according to a first embodiment of the present invention.

FIG. 2 is an external perspective view of the induction heating cooker.

FIG. 3 is a diagram showing a relationship between a heating coil and a magnetic body of the induction heating cooker.

FIG. 4 is a sectional view of an essential part of an induction heating cooker according to a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part of a conventional induction heating cooker.

FIG. 6 is a perspective view of a luminous body of a conventional induction heating cooker.

[Explanation of symbols]

1 body 2 top plate 7 Heated object 13 heating coil 14 Magnetic material 15 Luminescent device (light emitting means) 19 Temperature sensor device (temperature detection means)

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Claims (4)

[Claims] 1. A main body forming an outer shell, a top plate on the upper surface of the main body for mounting an object to be heated, and a heating coil provided below the top plate for induction heating the object to be heated, A magnetic body for preventing leakage of magnetic flux from the heating coil and a light emitting means for displaying a graphic on the top plate by light are provided, and the magnetic body is interposed between the light emitting means and the heating coil. Induction heating cooker. 2. The induction heating cooker according to claim 1, wherein a magnetic material is interposed between the heating coil and the temperature detecting means for detecting the temperature of the object to be heated or the top plate. 3. The induction heating cooker according to claim 1, wherein the magnetic body is vertically provided on at least one of the inner and outer circumferences of the heating coil and supports the lower side of the heating coil. 4. The induction heating cooker according to claim 1, wherein a high-frequency current not lower than 40 kHz is applied to the heating coil to induction-heat the object to be heated.