JP2020177870A - Induction cooker - Google Patents

Abstract

To provide an induction cooker that suppresses interference waves during cooking.SOLUTION: The induction cooker comprises a top plate 2 on which a heating object is placed, a heating coil 3 provided below the top plate 2 and performing induction heating on the heating object, a coil base 4 holding the heating coil 3, a ferrite 40 provided below the heating coil 3, and a demagnetization coil 31c generating magnetic flux in a direction in which the magnetic flux generated by the heating coil 3 is canceled, the demagnetization coil 31c is arranged below at least one of the vicinity of the outer peripheral side surface and the vicinity of the inner peripheral side surface of the heating coil 3.SELECTED DRAWING: Figure 5

Description

The present invention relates to an induction cooker.

In an induction heating cooker, a high-frequency current is passed through a heating coil, and a cooking pot placed on a top plate above the heating coil is heated by induction heating by a magnetic field line generated by the heating coil. ..

However, if these magnetic field lines leak out from the main body of the induction heating cooker, they may become interference waves and damage other wireless devices and electronic devices.

As a method for reducing this disturbing wave, the electromagnetic cooker shown in Patent Document 1 is known. An electromagnetic induction coil that heats the inner pot is placed on the outer periphery of the inner pot that holds the object to be heated, and a degaussing coil is placed on the outer periphery of the electromagnetic induction heating coil. By connecting the electromagnetic induction coil and the degaussing coil in series so as to flow in opposite directions, the heating magnetic flux generated by the electromagnetic induction coil and the degaussing magnetic flux generated by the degaussing coil interfere with each other to the outside of the main body. It reduces the leaked electromagnetic waves.

Japanese Unexamined Patent Publication No. 2004-288550

However, in the induction heating cooker, ferrite is provided on the opposite side of the surface of the heating coil facing the cooking pot to block magnetic leakage and efficiently generate an eddy current in the object to be heated. Patent Document 1 does not describe ferrite, and the arrangement of the degaussing coil when the ferrite is provided has not been studied.

An object of the present invention is to solve the above problems and to provide an induction heating cooker that suppresses disturbing waves during cooking.

In order to achieve the above object, the present invention includes a top plate on which the object to be heated is placed, a heating coil provided below the top plate for inductively heating the object to be heated, and a coil base for holding the heating coil. A ferrite provided below the heating coil and a demagnetizing coil that generates a magnetic flux in a direction that cancels the magnetic flux generated by the heating coil are provided, and below at least one of the vicinity of the outer peripheral side surface or the inner peripheral side surface of the heating coil. , The demagnetizing coil is arranged.

According to the present invention, it is possible to provide an induction heating cooker that suppresses interference waves during cooking.

Perspective view of the state where the induction heating cooker in one embodiment is incorporated in the system kitchen. Explanatory drawing of the state which removed the top plate of the induction heating cooker in one Example Explanatory drawing of the upper surface side of the heating coil for induction heating of one Example Explanatory drawing of the lower surface side of the heating coil for induction heating of one Example Explanatory drawing of schematic cross section of heating coil for induction heating of one Example

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5. The following description shows specific examples of the contents of the present invention, and the present invention is not limited to these descriptions. Various changes and modifications by those skilled in the art are possible within the scope of the technical ideas disclosed herein. Further, in all the drawings for explaining the present invention, those having the same function may be designated by the same reference numerals, and the repeated description thereof may be omitted.

FIG. 1 is a perspective view of a state in which a cooking heater, which is an induction heating cooker of one embodiment, is installed in a system kitchen 13.

The main body 1 of the induction heating cooker is provided with a top plate 2 on the upper surface on which an object to be cooked (not shown) is placed on a pan.

The top plate 2 is surrounded by a top frame 2a, and a mounting portion 9 (right mounting portion 9a, left mounting portion 9b, central mounting portion) indicating a position on which the food to be cooked is placed is placed on the top surface. 9c) is provided. Below the top plate 2 in the mounting portion 9, heating coils 3 (heating coils 3a, 3b, 3c on the right side, left side, and central back side) for heating the object to be heated are arranged.

On the front side of the top plate 2, an operation unit 11 (right operation unit 11a, left operation unit 11b, center operation unit 11c) for setting the thermal power of the heating coil 3 and the display panel 10 attached thereto are provided. Has been done.

An exhaust port 7 is provided on the back side of the top plate 2.

A roaster 14 is provided on the left side of the front surface of the main body 1. An operation panel 15 for operating the main power supply 16 and the roaster 14 is provided on the right side of the front surface.

FIG. 2 is a perspective view with the top plate 2 removed.

The main body 1 is provided with an inverter circuit (not shown) that supplies a high frequency current to the heating coils 3a, 3b, 3c, etc. below the heating coil 3 described above. Further, an intake port 6 is provided behind the main body 1. In order to cool the heating coil 3, the inverter board constituting the inverter circuit, and the heat-generating electronic components in the control board, the fan device 8 sucks the outside air into the main body 1 through the intake port 6. The outside air taken in by the fan device 8 is exhausted to the outside of the main body 1 through an exhaust port 7 provided behind the main body 1 after cooling the heating coil 3 and the electronic parts which are heat generating parts.

FIG. 3 is an upper perspective view of a heating coil for induction heating of one embodiment. With reference to FIG. 3, a coil unit 5b provided with the left side heating coil 3b will be described on behalf of the heating coil 3.

The coil unit 5b is configured by using the coil base 4 as a skeleton and attaching a plurality of parts described later.

In the coil unit 5b, a temperature detecting means 12 for detecting the temperature of the bottom surface of the object to be heated is provided on the surface side (upper surface side of the coil unit 5b) facing the top plate 2. The temperature detecting means is provided in the central portion 4a of the coil base 4. As the temperature detecting means 12, a contact-type thermistor type that detects the temperature of the pot bottom through the top plate 2, a non-contact type infrared sensor that detects infrared rays radiated from the pot bottom, or the like is used.

Further, a heating coil 3 for inducing heating the object to be heated is provided on the outer periphery of the temperature detecting means 12 provided in the central portion 4a. In the heating coil 3, the stranded wire obtained by twisting a plurality of conducting wires is divided into two spirally formed and held in a plane on the coil base 4. The spirally divided heating coil is provided with an inner heating coil 31a wound around the central portion 4a and an outer heating coil 31b arranged with an annular gap on the outer side thereof. The inner heating coil 31a and the outer heating coil 31b are electrically connected in series and wound in the same direction.

On the outer peripheral portion 4b of the outer heating coil 31b of the heating coil 3, the magnetic field generated by the heating coil 3 is prevented from spreading to the outside of the outer heating coil 31b, and the object to be heated placed in the mounting portion 9 is efficiently applied. A ring-shaped magnetic shield ring 17 made of a non-magnetic material is provided so that the material can be heated well.

Further, a plurality of L-shaped rod-shaped ferrites 40 (FIG. 5) are arranged on the lower surface of the coil base 4 to which the heating coil 3 is fixed. The ferrite 40 is fixed to the coil base 40. As a result, the magnetic field lines generated by the heating coil 3 can be guided toward the object to be heated, magnetic leakage to the side opposite to the object to be heated can be blocked, and an eddy current can be efficiently generated in the object to be heated. .. Then, the cooking pot can be heated efficiently. In order to cool the ferrite 40, the entire ferrite 40 is exposed without being covered. The details of the arrangement of the ferrite 40 will be described later.

Next, the surface side (lower surface side of the coil unit 5b) that is not opposed to the top plate 2 will be described with reference to FIGS. 4 and 5.

FIG. 4 is a view of the heating coil for induction heating of one embodiment as viewed from the lower surface, and FIG. 5 is a schematic cross-sectional view of the heating coil for induction heating of one embodiment.

The ferrite 40 arranged on the lower surface of the coil base 4 to which the heating coil 3 is fixed has an L-shaped rod shape having a longitudinal portion 40a and a lateral portion 40b. The longitudinal portion 40a is arranged radially from the central portion 4a toward the outer peripheral portion 4b. In other words, it is provided so as to intervene between the inner heating coil 31a wound around the central portion divided into two and the outer heating coil 31b arranged with an annular gap on the outer side thereof. The short side portion 40b is provided on the outer peripheral portion 4b side, and extends in the direction of the top plate 2 (object to be heated). That is, the short portion 40b has a shape extending from the lower side to the upper side of the heating coil in the vicinity of the outer peripheral side surface of the heating coil.

Further, a demagnetizing coil 31c is provided on the central portion 4a side of the lower surface of the coil base 4. The demagnetizing coil 31c is electrically connected in series with the heating coil 3 (inner heating coil 31a and outer heating coil 31b) wound on the upper surface of the coil base 4, and the winding directions are opposite to each other.

Further, two terminal blocks 22 are provided on the lower surface of the coil base 4, and connection terminals 21 are fixed to the terminal blocks 22. Then, the lead wire 32b drawn from one end of the heating coil 3 and the lead wire 32a drawn out from the other end of the heating coil 3 after forming the demagnetizing coil 31c are connected to the connection terminal 21. ing. However, the terminal block 22 may be provided on the side surface of the coil base 4, or may be provided as a separate body independently of the coil base 4.

The demagnetizing coil 31c will be described with reference to FIG.

When the object to be heated is induced and heated, the heating coil 3 (inner heating coil 31a and outer heating coil 31b) provided on the upper surface of the coil unit 5 facing the top plate 2 generates an interfering wave. In order to reduce this disturbing wave, the demagnetizing coil 31c generates a magnetic flux 80 in a direction opposite to the direction of the magnetic flux 70 that induces and heats the object to be heated generated by the heating coil 3. Since the magnetic flux 70 and the magnetic flux 80 are oriented so as to cancel each other out, it is possible to suppress the interfering wave.

The demagnetizing coil 31c provided in series with the heating coil 3 is wound in the direction opposite to the winding direction of the heating coil 3. As a result, the current flows through the demagnetizing coil 31c in the direction opposite to the direction of the current 50 flowing through the heating coil 3 (clockwise in FIG. 5). Therefore, the disturbing wave can be reduced by the opposite directions of the current 50 flowing through the heating coil 3 and the direction of the current 60 (counterclockwise in FIG. 5 in this case) flowing through the demagnetizing coil 31c.

In this embodiment, since the short side portion 40b of ferrite is provided on the outer peripheral portion 4b side, the demagnetization coil 31c is provided near the central portion 4a side of the lower surface of the coil base 4. That is, among the vicinity of the outer peripheral side surface or the inner peripheral side surface of the heating coil, the demagnetization coil is located below the inner peripheral side surface, which is the other side of the vicinity of the outer peripheral side surface where ferrite extends from the lower side to the upper side of the heating coil. 31c was provided. The position where the demagnetizing coil 31c is provided is not limited to this. The same effect can be obtained by providing the same configuration below the heating coil 3.

In this embodiment, the temperature detecting means 12 for detecting the temperature of the bottom surface of the object to be heated is provided in the central portion 4a of the coil base 4. Therefore, it is difficult to provide ferrite facing the direction of the top plate 2 (object to be heated) on the central portion 4a side. Therefore, in this embodiment, an L-shaped ferrite 40 in which a short portion 40b directed toward the object to be heated is provided only on the outer peripheral portion 4b is adopted. As shown in FIG. 5, the endmost coil 31e of the heating coil 3 on the central portion 4a side is opened without being covered with ferrite. Therefore, the direction of the magnetic flux generated on the central portion 4a side cannot be controlled. Therefore, in order to prevent the magnetic flux generated on the central portion 4a side from leaking to the outside of the main body and becoming an interfering wave, a demagnetizing coil 31c is provided on the central portion 4a side. In other words, a demagnetization coil is provided below the endmost coil 31e near the outer peripheral side surface of the heating coil. As a result, the disturbing wave can be suppressed efficiently.

On the other hand, when an I-type ferrite having no short portion 40b is used, the endmost coil of the heating coil 3 on the central portion 4a side and the outer peripheral portion 4b side is opened without being covered with the ferrite for the reason described above. Become. Therefore, a demagnetizing coil 31c is provided below the central portion 4a side and the outer peripheral portion 4b side. In other words, demagnetizing coils are provided near the outer peripheral side surface and the inner peripheral side surface of the heating coil. As a result, the disturbing wave can be suppressed efficiently.

In the above embodiment, an example in which the demagnetizing coil 31c is connected to the inner heating coil 31a has been described. However, it may be connected to the outer heating coil 31b side.

When the demagnetizing coils 31c are provided on both the central portion 4a side and the outer peripheral portion 4b side, they may be individually connected to the inner heating coil 31a side and the outer heating coil 31b side, or may be connected to either side. You may.

Further, by increasing or decreasing the number of turns of the demagnetizing coil 31c, it is possible to correspond to the magnitude of the disturbing wave to be suppressed.

1 Main body 2 Top plate 3 Heating coil 4 Coil base 5 Coil unit 12 Temperature detecting means 31a Inner heating coil 31b Outer heating coil 31c Demagnetizing coil 31e End side coil 32 Lead wire 40 Ferrite 50, 60 Current 70, 80 Magnetic flux

Claims (2)

A top plate on which the object to be heated is placed and
A heating coil provided below the top plate for inducing heating the object to be heated,
A coil base that holds the heating coil and
Ferrite provided below the heating coil and
A demagnetizing coil that generates magnetic flux in a direction that cancels the magnetic flux generated by the heating coil is provided.
An induction heating cooker in which the demagnetizing coil is arranged below at least one of the vicinity of the outer peripheral side surface and the vicinity of the inner peripheral side surface of the heating coil. In the induction heating cooker according to claim 1,
The ferrite has a shape extending from the lower side to the upper side of the heating coil in either the vicinity of the outer peripheral side surface or the vicinity of the inner peripheral side surface of the heating coil.
An induction heating cooker in which the demagnetizing coil is arranged below the vicinity of the other side surface in the vicinity of the side surface on which the ferrite extends.

Images