JPH09223574A - Induction heating cooking appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin type induction heating cooking appliance by which a magnetic field leaking downward from a main body bottom surface and to the periphery can be reduced. SOLUTION: Ferrite cores 30a and 30c are arranged in the long side direction of a cooling fin 17 on which a projected shape in the direction of a heating coil 29 is an almost rectangular shape and the direction vertical to a blade 17a of the cooling fin 17, and an angle between a ferrite core 30b and a ferrite core 30c is made narrower than that between the other adjacent ferrite cores. Therefore, a thin type induction heating cooking appliance by which a magnetic field leaking downward from a main body bottom surface and to the periphery is reduced can be obtained.

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 provided with magnetic shield means for reducing a magnetic field generated from a heating coil.

[0002]

2. Description of the Related Art In recent years, induction heating cookers that induce eddy currents in the bottom of a load pan by a high-frequency magnetic field to heat them have been required to have higher output, and it is necessary to effectively suppress magnetic fields leaking to the surroundings. Is becoming.

[0003] A conventional induction heating cooker will be described below. FIG. 3 (a) is a plan view showing the structure of a heating coil of a conventional induction heating cooker, and FIG. 3 (b) is a sectional view showing the case where the heating coil is incorporated in the housing of the induction heating cooker. In FIG. 3A or FIG. 3B, the heating coil 1 wound in a disk shape is placed on the heating coil holding base 2, and the heating coil 1 is placed between the coil holder 3 and the heating coil holding base 2. The outer peripheral portion is sandwiched, and the coil holder 3 is fixed to the heating coil holding base 2 by screwing.

On the lower surface of the heating coil holder 2, four substantially rectangular parallelepiped rod-shaped ferrite cores 5a to 5 are formed.
d are respectively provided from the outer peripheral side of the heating coil 1 toward the center of the heating coil 1, and the intervals (angles) between the ferrites are substantially equal (equal angles), that is, the angles between the adjacent ferrite cores are equal to each other. It is about 90 degrees. Further, the upper surfaces of the ferrite cores 5a to 5d and the lower surface of the heating coil 1 are substantially equal to each other, and the distances from the center of the heating coil to the inner ends of the ferrites 5a to 5d are substantially equal to each other. ing.

The heating coil holding base 2 is fixed to the upper part of a column provided on the bottom surface of the housing 6, and the heating coil 1 is located below the top plate 7 on which the load pan is placed. In addition, below the ferrite cores 5a to 5d, electrical components such as a switching semiconductor 9 that constitutes an inverter that supplies a high-frequency current to the heating coil 1, cooling fins 10 made of aluminum for cooling the switching semiconductor 9, and control. A printed wiring board 8 on which circuit components and the like are placed is fixed to the housing 6. A disk-shaped shield plate 4 made of aluminum is placed on the bottom surface of the housing 6 so as to be located below the heating coil.

In the above structure, when a high-frequency current is supplied to the heating coil 1 from the inverter, a magnetic field is generated from the heating coil 1, magnetic flux is linked to the load pan on the top plate 7, and an induced current is generated in the load pan. Heat the load pan with heat. A magnetic field is also generated below the heating coil 1, but since the ferrite cores 5a to 5d are arranged,
The lower magnetic flux concentrates on the ferrite cores 5a to 5d and prevents the magnetic flux from spreading downward. Ferrite cores 5a-5
The shield plate 4 shields the downward magnetic field of the heating coil which cannot be shielded only by d.

[0007]

However, in the conventional induction heating cooker described above, when the distance between the shield plate 4 and the printed wiring board 8 is reduced, the lead wire of the electronic component protruding to the back surface of the printed wiring board 8 is formed. Since there is a risk that the printed wiring board 8 will touch and short-circuit different parts, there is a limit to reducing the height of the product.

Further, the magnetic flux generated by the heating coil 1 interlinks with the cooling fin 10 made of aluminum, and an induced current is generated in the cooling fin 10. The anti-magnetic flux generated by the induced current is generated by the heating coil 1. There is a problem that the distribution of the magnetic field that is superposed on the magnetic flux and leaks around the heating coil 1 is affected, and the leakage magnetic field in a specific direction becomes strong.

If the heating coil 1 is disk-shaped, the horizontal distribution of the magnetic field, which should be almost omnidirectional, changes to one having directivity under the influence of the cooling fins, etc. There was a problem that the leakage magnetic field in a specific direction increased when viewed. That is, the heating coil 1 is wound in a substantially disc shape, and the horizontal distribution of the magnetic field generated from the heating coil 1 is obtained by plotting points of equal magnetic fields and connecting them with a line.
Is similar to the outer peripheral shape of the heating coil 1, that is, a substantially circular shape, and if the horizontal distance from the center of the heating coil 1 is the same, no matter what direction the magnetic field is viewed from the center of the heating coil 1, the magnetic field strength is almost the same. Generally, the magnetic field distribution is omnidirectional, that is, However, since the induction heating cooker has a frequency conversion device such as an inverter and requires the cooling fins 10 for cooling the switching elements thereof, the cooling fins 10 are made of a conductive metal such as aluminum and have a cooling capacity of The shape is increased for the purpose of increasing the height, and blades are provided to increase the surface area, resulting in a complicated shape with unevenness. When the cooling fin 10 is arranged close to the lower part of the heating coil 1 in order to reduce the thickness and size of the induction heating cooker, the amount of magnetic flux generated by the heating coil 1 interlinking with the cooling fin 10 is generated. If the heating coil 1 is disc-shaped, the horizontal distribution of the magnetic field, which should be almost omnidirectional as described above, is changed to one having directivity due to the influence, and it is seen from the center of the heating coil 1. Therefore, there is a problem that the leakage magnetic field in a specific direction increases.

[0010]

A first means of the present invention for solving the above-mentioned problems is to provide a heating coil disposed in the vicinity of the load so as to face the load, and a frequency for supplying a high-frequency current to the heating coil. A converter and a plurality of magnetic bodies located near the heating coil on the side opposite to the load, spaced apart around the center of the heating coil, and arranged in a substantially central direction from the outer peripheral side of the heating coil. Magnetic shield means,
The cooling element includes a cooling fin that cools a switching element of the frequency conversion device and that is arranged in the vicinity of the heating coil and has a substantially rectangular projection shape in the heating coil direction. The magnetic shield means is arranged so as to overlap the shape, and at least one of the magnetic bodies is arranged in the long side direction of the substantially rectangular shape of the projected shape of the cooling fin.

The second means of the present invention is to provide a heating coil arranged near the load so as to face the load, a frequency converter for supplying a high-frequency current to the heating coil, and the heating coil on the opposite side of the load. A magnetic shield means, which is located in the vicinity of the heating coil, is provided around the center of the heating coil and is spaced from the outer circumference of the heating coil in a substantially central direction, and is close to the heating coil. A cooling fin for cooling a switching element or the like of the frequency conversion device having blades arranged so that the projected shape in the heating coil direction and the center of the heating coil are overlapped with each other, and The magnetic shield means is configured such that at least one magnetic body is arranged in the vicinity of a direction perpendicular to the blades of the cooling fin.

The third means of the present invention is to provide a heating coil arranged near the load so as to face the load, a frequency conversion device for supplying a high frequency current to the heating coil, and the heating coil on the opposite side of the load. A magnetic shield means, which is located in the vicinity of the heating coil, is provided around the center of the heating coil and is spaced from the outer circumference of the heating coil in a substantially central direction, and is close to the heating coil. And a cooling fin for cooling the switching element of the frequency conversion device and the like, the cooling fin is arranged so that the projected shape in the heating coil direction and the center of the heating coil are overlapped, and the magnetic shield means is According to the strength distribution of the magnetic field leaking from the heating coil, the angle formed by two adjacent magnetic bodies is changed.

Further, a fourth means of the present invention has the structure of the above-mentioned third means, and the magnetic shield means is provided in the vicinity of the long side of the projection shape of the cooling fin in the heating coil direction, or The distribution density of the magnetic material in the vicinity of the direction perpendicular to the blades of the cooling fin is made larger than that in the other direction.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the invention described in claim 1, when a high frequency current is supplied to the heating coil from the frequency converter, both sides of the surface of the winding of the heating coil (hereinafter referred to as the heating coil surface) are formed. It generates a magnetic flux and heats a load placed opposite to one side of it, but on the other hand, it is located near the heating coil on the side opposite to the side where the load is located and heats it with a space around the center of the heating coil. Since the magnetic shield means having a magnetic material such as a plurality of ferrite cores arranged from the vicinity of the outer circumference of the coil to the substantially central direction is provided, the high frequency magnetic flux generated on the side of the heating coil where the magnetic material is provided is magnetic. Concentrate on the body and suppress magnetic flux from spreading to the space other than the load side. In addition, a cooling fin that cools heat-generating components such as a switching element and a rectifier of the frequency conversion device, is provided in the vicinity of the heating coil, and has a substantially rectangular projection shape in the heating coil direction, and the center of the heating coil is the cooling fin. Since it is arranged so as to overlap with the projected shape of the above, the effect of shielding the leakage magnetic field that cannot be shielded by the ferrite core with the cooling fin by the magnetic field radiated downward from the heating coil becomes large, and conventionally, separately from the bottom surface of the casing. It is possible to omit the shield plate provided in the. Further, since the shape of the cooling fin is substantially rectangular when viewed from the heating coil, the magnetic field leaking from the heating coil to the surroundings is particularly due to the magnetic field of the heating coil when the heating coil and the cooling fin are close to each other. Although the magnetic shield means spreads in the long side direction of the cooling fin due to the influence of the demagnetizing field generated by the current induced in the cooling fin, at least one magnetic body has a substantially rectangular length of the projection shape in the heating coil direction of the cooling fin. Since they are arranged in the side direction, the spread of the magnetic field in that direction can be suppressed.

According to the second aspect of the present invention, since the cooling fin is arranged close to the heating coil and the projected shape in the heating coil direction and the center of the heating coil are overlapped with each other, the cooling fin is located below the heating coil. The effect of shielding the leakage magnetic field, which cannot be completely shielded by the ferrite core, by the radiated magnetic field by the cooling fins becomes large, and the shield plate conventionally provided separately on the bottom surface of the housing can be omitted. Further, if the cooling fins are provided with blades, the heat dissipation area is increased and the cooling efficiency is improved. However, when the heating coil and the cooling fins are close to each other, the magnetic field of the heating coil causes a current induced in the blades of the cooling fins to occur. Due to the influence of the magnetic field, the magnetic field leaking from the heating coil to the surroundings spreads in the direction perpendicular to the side surface of the blade of the cooling fin, but in the magnetic shield means, at least one magnetic body is perpendicular to the blade of the cooling fin. Since it is arranged in the vicinity of the direction, the spread of the magnetic field in that direction can be suppressed.

According to the third aspect of the present invention, since the cooling fins are arranged close to the heating coil and the projected shape in the heating coil direction and the center of the heating coil are overlapped with each other,
The effect of shielding the leakage magnetic field, which cannot be completely shielded by the ferrite core, by the cooling fins by the magnetic field radiated downward from the heating coil is large, and the shield plate conventionally provided separately on the bottom surface of the housing can be omitted. Further, since the magnetic shield means changes the angle formed by two adjacent magnetic bodies according to the magnetic field strength distribution leaking from the heating coil, the magnetic field suppressing action in a specific direction is increased, and the cooling fins and other By disposing the conductive component in a place where the magnetic field of the heating coil is strong, it is possible to suppress the magnetic field from spreading in a specific direction and reduce the leakage magnetic field.

According to a fourth aspect of the present invention, the distribution density of the magnetic material of the magnetic shield means is in the other direction near the long side direction of the projection shape of the cooling fin in the direction of the heating coil or near the direction perpendicular to the blades of the cooling fin. Since it is made larger, the directivity of the magnetic field suppressing effect of the magnetic substance cancels out the directivity of the magnetic field distribution of the heating coil caused by the effect of the cooling fins arranged in close proximity to the heating coil, thus making it non-directional. It is possible to realize a uniform magnetic field distribution and reduce the leakage magnetic field.

[0018]

【Example】

(Embodiment 1) A first embodiment of the present invention will be described below with reference to the drawings. In the plan view showing the inside of the induction heating cooker in FIG. 1, a cooling fan motor 12 and a fan blade 13 are fixed by a motor holder 14 on an inlet port of a corner portion of a resin chassis 11. The printed wiring board 16 has a cooling fin 17 and a switching transistor (not shown) cooled by the cooling fin 17.
Power components such as a rectifier (not shown), a resonance capacitor 18, a high frequency power supply capacitor 19, a filter coil 20 and the like, and a control circuit for the switching transistor are mounted and connected by soldering. The cooling fin 17 has ten blades standing perpendicular to the bottom surface, and the blades are standing parallel to each other and toward the exhaust port 22. A printed wiring board 23, on which display components such as LEDs and input components such as switches are placed, is arranged in the front part, and a magnet plug 24 is provided in the rear part. Here, the magnet plug 24 is a connection plug that can be attached and detached by a magnet in order to connect to a commercial power source. This connection plug has a printed wiring board 25
Is attached to connect the internal power supply wire 26 and the electrode of the magnet plug 24.

3 vertically set on the bottom surface of the chassis 11
The heating coil support plate 27 shown by the broken line is placed and fixed on the columns 28a, 28b, 28c of the book.
A doughnut-shaped heating coil 29 indicated by a broken line is placed and fixed on top of 7. Four ferrite cores 30a, 30b, 30c, 30d are radially fixed to the lower surface of the heating coil holding plate 27 from the center of the heating coil 29. In the planar positional relationship, the center of the heating coil 29 is near the center of the cooling fin 17, and the angle between the ferrite core 30a and the ferrite core 30d and the angle between the ferrite core 30d and the ferrite core 30c are both approximately equal. Although it is 90 degrees, the angle formed by the ferrite core 30c and the ferrite core 30b is about 60 degrees.

The induction heating cooker configured as described above will be described below. When the heating operation is started, a high frequency current of about 20 kHz is generated in the inverter circuit formed by the switching transistor, the resonance capacitor 18, the high frequency power supply capacitor 19, and the heating coil 29. When a high frequency current flows through the heating coil 29, a high frequency magnetic field is generated on both surfaces of the heating coil 29. The magnetic field generated above the heating coil 29 interlinks with the bottom of the load pan and induces an induced current in the pan bottom to generate Joule heat. The magnetic field generated below the heating coil 29 partially passes through the ferrite cores 30a to 30d, returns to the heating coil, partially interlinks with the cooling fin 17, and partially leaks toward the bottom surface of the device.

The magnetic field also leaks around the heating coil 29, that is, at a position laterally separated from the device. Since the heating coil 29 is wound in a disc shape, a concentric magnetic field distribution should be generated with the center of the heating coil 29 as the center, but the magnetic field of the heating coil 29 is linked to the cooling fins 17. The demagnetizing field generated by the induced current induced on the surface of the cooling fin 17 causes the above-mentioned heating coil 29.
Superposed on the magnetic field to disturb the concentric magnetic field distribution, and generate directivity. Since the shape of the cooling fin 17 is rectangular when viewed from above (the heating coil direction), the most magnetic flux of the heating coil 29 interlinks with the cooling fin 17 in the long side direction, and the magnetic field distribution of the heating coil 29 is in that direction. Spreads and the directivity becomes stronger. Further, when the magnetic lines of force generated by the heating coil 29 interlink perpendicularly with the side wall of the blade of the cooling fin 17 such as 17a, the largest induced current is induced on the surface of that wall, and the largest demagnetizing field is generated. , Feather 17
The magnetic field in the direction perpendicular to a is most likely to be disturbed.

On the other hand, a rod-shaped ferrite core 30a and a ferrite core 30c, which are provided from the center of the heating coil 29 toward the outer peripheral direction, are arranged along the long side direction of the cooling fin 17 in a planar positional relationship. Further, it is arranged so as to be substantially perpendicular to the blades 17a of the cooling fins 17, and the direction in which the magnetic field suppressing effect by the ferrite core is maximized, and the expansion of the magnetic field distribution by the heating coil 29 due to the influence of the cooling fins 17 as described above. By making the easy directions substantially coincide with each other, the directivity of the magnetic field distribution is relaxed to suppress the leakage magnetic field from becoming strong in a specific direction. Further, by setting the angle formed by the ferrite cores 30b and 30c to about 60 degrees and making it the smallest among the angles formed by other adjacent ferrite cores, the direction (as viewed from the center of the heating coil 29) of It is possible to suppress the spread of the leakage magnetic field by making the distribution of the magnetic flux density larger than the other directions and further making the directivity of the magnetic field closer to omnidirectional.

As described above, according to the present embodiment, the center of the heating coil 29 overlaps the projected shape of the cooling fin 17 in the direction of the heating coil 29, that is, in the above case, the upper surface of the cooling fin 17 is the heating coil. Since the cooling fin 17 is disposed close to the lower part of the center of the heating coil 29 so as to be located in the lower center of the device, the effect that the cooling fin 17 reduces the magnetic field of the heating coil 29 in the device bottom direction becomes large. The magnetic field of the heating coil 29 leaking downward from the bottom is reduced. Therefore, it is not necessary to provide a shield member such as an aluminum plate on the bottom surface of the device.

Further, since the ferrite core 30a and the ferrite core 30c are provided along the long side direction of the cooling fin 17 having a rectangular shape when viewed from the side of the heating coil 29, it is provided near the central portion of the heating coil 29. Further, due to the rectangular shape of the cooling fins 17, it is possible to suppress the generation of directivity in the magnetic field distribution of the heating coil 29, and to suppress the leakage magnetic field from increasing in a specific direction.

Further, since the ferrite core 30a and the ferrite core 30c are arranged perpendicularly to the blades 17a of the cooling fin 17, the blades 17a perpendicular to the direction of the magnetic lines of force of the heating coil 29 cause the heating coil 29 to move. It is possible to suppress the generation of directivity in the magnetic field distribution and suppress the increase of the leakage magnetic field in a specific direction.

Further, among the four ferrite cores serving as the magnetic shield means, according to the magnetic field intensity distribution leaking from the heating coil 29 (corresponding to the magnetic field distribution which could not be sufficiently rendered non-directional by the above-mentioned configuration). , Adjacent ferrite cores 30
Since the angle formed by b and 30c is set to 60 degrees and is changed with respect to the angle formed by other adjacent ferrite cores of 90 degrees,
Directional heating coil 29 generated by the influence of the cooling fin 17 and other conductive or magnetic parts
It is possible to reduce the leakage magnetic field by making the distribution of the magnetic field of 1 closer to non-directional.

Although the number of ferrite cores is set to four, the number is not limited to this, and the number and size of ferrite cores used to reduce the directivity depend on the directivity of the entire device. And decide. Similarly, depending on the material of the ferrite core and the size of the cooling fin, the ferrite core 30c and the ferrite core 30d may be different.
If the angle formed by is close to about 60 degrees, it may be possible to further approximate the overall omnidirectionality.

(Embodiment 2) A second embodiment of the present invention will be described below with reference to FIG. Heating coil holding plate 31, heating coil 32, four ferrite cores 33
Reference numerals a, 33b, 33c and 33d have the same shapes as the heating coil holding plate 27, the heating coil 29 and the four ferrite cores 30a, 30b, 30c and 30d in FIG. 1 of the first embodiment. The heating coil 32 is formed by winding a litz wire in a spiral shape, and only the winding start portion and the winding end portion are shown and the intermediate portion is omitted. What is different from FIG. 1 is that the shape of the cooling fin 34 when viewed from the side of the heating coil 32 is a square, and the center of the square and the center of the heating coil 32 coincide in a planar position.
About 9 ferrite cores 30a, 30b, 30c, 30d
That is, they are evenly arranged around the center of the heating coil 32 at an angular interval of 0 degree.

The induction heating cooker configured as described above will be described below. The distribution of the magnetic field generated by the heating coil 32 is influenced by the cooling fins 34, but the center of the cooling fins 34 and the center of the heating coil 32 are at the same planar position, and the cooling fins 34 seen from the heating coil 32 side.
Since the cooling fin 34 has a square shape, if the cooling fins 34 are flat without the blades 34a that are wall-shaped projections on the upper surface of the cooling fins 34, the directivity of the magnetic field distribution does not become strong, but since there are blades 34a, Strong directivity is generated in the direction perpendicular to the wall of the blade 34a. However, the ferrite core 33a,
Since 33b is arranged along the direction perpendicular to the blades 34a, the directivity of the magnetic field distribution of the heating coil 32 due to the influence of the blades 34a is relaxed and the leakage magnetic field is prevented from becoming large in a specific direction. You can

[0030]

As described above, according to the invention described in claim 1, the heating coil is located in the vicinity of the heating coil on the side opposite to the load, with a space provided around the center of the heating coil, and substantially from the outer peripheral side of the heating coil. Cooling fin having a plurality of magnetic bodies arranged in the same direction, a switching element of the frequency conversion device, and the like, which are arranged close to the heating coil, and have a projection shape in the heating coil direction that is substantially rectangular. The heating coil is arranged such that the center of the heating coil overlaps with the projected shape of the cooling fin, and the magnetic shield means has at least one of the magnetic bodies arranged in a long side direction of a substantially rectangular shape of the projected shape of the heat sink. Since it is installed, the effect that the magnetic field radiated downward from the heating coil shields the leakage magnetic field that cannot be completely shielded by the ferrite core with the cooling fins. Omitted shield plate which has been provided in the housing bottom surface, and inexpensive thin, it is possible to provide a small induction heating cooker of magnetic field leaking around the heating coil.

According to the second aspect of the invention, the cooling fins are arranged close to the heating coil, and
Since the projection shape in the heating coil direction and the center of the heating coil are arranged to overlap with each other, and the magnetic shield means has at least one magnetic body arranged in the vicinity of the direction perpendicular to the blades of the cooling fin, the magnetic shield means is located below the heating coil. The magnetic field that radiates to
The effect of shielding the leakage magnetic field that cannot be completely shielded by the ferrite core with the cooling fins becomes large, and the shield plate that was conventionally provided separately on the bottom of the housing is omitted, and it is thin and inexpensive, and the magnetic field that leaks from the heating coil to the surroundings. It is possible to provide an induction heating cooker with a small amount of heat.

According to the third aspect of the present invention, the cooling fins are arranged close to the heating coil so that the projected shape in the direction of the heating coil and the center of the heating coil overlap.
Since the magnetic shield means changes the angle formed by two adjacent magnetic bodies according to the magnetic field strength distribution leaked from the heating coil, the shield plate conventionally provided on the bottom surface of the housing is omitted, and it is thin and inexpensive. Further, it is possible to provide an induction heating cooker with a small magnetic field leaking from the heating coil to the surroundings.

Further, according to the invention described in claim 4, the cooling fin is arranged in the vicinity of the heating coil so that the projected shape in the direction of the heating coil and the center of the heating coil are overlapped with each other, and the magnetic shield means is cooled. Since the distribution density of the magnetic material in the vicinity of the long side of the projection shape of the fin in the direction of the heating coil or in the vicinity of the direction perpendicular to the blades of the cooling fin is made larger than the other directions, the shield conventionally provided on the bottom surface of the housing It is possible to provide an induction heating cooker that omits a plate, is thin, is inexpensive, and has a small magnetic field leaking from the heating coil to the surroundings.

[Brief description of drawings]

FIG. 1 is an internal plan view of an induction heating cooker according to a first embodiment of the present invention.

FIG. 2 is a plan view of a main part of an induction heating cooker according to a second embodiment of the present invention.

FIG. 3A is a plan view of a main part of a conventional induction heating cooker, and FIG. 3B is a sectional view of the induction heating cooker.

[Explanation of symbols]

17 Cooling fin 29 Heating coil 30a, 30b, 30c, 30d Ferrite core (magnetic shield means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Tominaga 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A heating coil disposed near the load so as to face the load, a frequency conversion device for supplying a high-frequency current to the heating coil, and a heating coil located near the heating coil on the opposite side of the load, A magnetic shield means having a plurality of magnetic bodies arranged in a substantially central direction from the outer peripheral side of the heating coil and having a space around the center of the heating coil, and cooling the switching element of the frequency conversion device, and the heating coil. And a cooling fin having a projection shape in the heating coil direction having a substantially rectangular shape, the cooling fin being arranged so that the projection shape in the heating coil direction overlaps the center of the heating coil, and The magnetic shield means is an induction heating cooker in which at least one of the magnetic bodies is arranged in a long side direction of a substantially rectangular shape of the projected shape of the cooling fin. 2. A heating coil disposed in the vicinity of the load so as to face the load, a frequency conversion device for supplying a high-frequency current to the heating coil, and a heating coil located on the opposite side of the load from the heating coil. A magnetic shield means having a plurality of magnetic bodies arranged in a substantially central direction from the outer peripheral side of the heating coil and having a space around the center of the heating coil, and cooling the switching element of the frequency conversion device, and the heating coil. And a cooling fin having vanes, the cooling fin being arranged so that a projected shape in the heating coil direction overlaps the center of the heating coil, and the magnetic shield means is configured to An induction heating cooker in which at least one of the bodies is arranged in a direction substantially perpendicular to the blades of the cooling fins. 3. A heating coil arranged near the load so as to face the load, a frequency converter for supplying a high-frequency current to the heating coil, and a heating coil located near the heating coil on the opposite side of the load. A magnetic shield means having a plurality of magnetic bodies arranged in a substantially central direction from the outer peripheral side of the heating coil and having a space around the center of the heating coil, and cooling the switching element of the frequency conversion device, and the heating coil. Cooling fins arranged in close proximity to each other, wherein the cooling fins are arranged such that the projected shape in the heating coil direction overlaps the center of the heating coil, and the magnetic shield means leaks from the heating coil. An induction heating cooker that changes the angle between two adjacent magnetic bodies according to the magnetic field strength distribution. 4. The magnetic shield means increases the distribution density of the magnetic material in the vicinity of the long side of the projected shape of the cooling fin in the direction of the heating coil, or in the vicinity of the direction perpendicular to the blades of the cooling fin, as compared with other directions. The induction heating cooker according to claim 3.