JPH1126143A - Electromagnetic induction heating coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To focus a magnetic flux on the center of a heating material efficiently, uniformly heat by induction the whole heating material by arranging a work coil on the heating material side of a non-magnetic material plate, and inserting a ferrite core into the central space of the work coil to ensure a magnetic flux path in the central part of the work coil. SOLUTION: A coil wire 2' is wound in one layer except for a space S in the central part on the bottom surface of a non-magnetic material plate 1 made of heat resistant glass for example to form a work oil 2. A ferrite core 4 is inserted into the space S, and a copper pipe 7 having slits and a copper ring 8 are arranged in the surrounding of the ferrite core 4. A radiate ferrite core 6 whose one end is connected to the ferrite core 4 through a ferrite table plate 10 and other end is connected to the main ferrite 3 is arranged on the lower side of the work coil 2, and they are supported with aluminum plates 11, 12. Electricity is passed to the work coil 2 through terminals 13, 13', a magnetic flux 5 generated is focused on the ferrite core 4 through the main ferrite 3' and the radiate ferrite core 6, and uniformly supplied to a pan 9 from the center over the whole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic induction heater for an object to be heated such as a pot.

[0002]

2. Description of the Related Art A work coil attached to a general electromagnetic induction heater has a spiral shape, and the induction heating by this means cannot heat a central portion of an object to be heated such as a pan.

Conventionally, as shown in FIGS. 11 and 12, a non-magnetic metal plate 14 (a plate for controlling eddy current, such as a copper or aluminum plate) is disposed between a coil and a pot. In this case, the non-magnetic metal plate 1
Since 4 is used for heating the pan, a large current must be applied to the metal plate 14.

Accordingly, the size of the non-magnetic metal plate 14 is increased to some extent. Further, the non-magnetic metal plate 14 is also heated, so that there is a problem that energy loss is large and efficiency is deteriorated.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to uniformly and efficiently heat the bottom of a cooking pot from the center of the cooking pot by electromagnetic induction heating.

[0006]

In order to achieve the above object, according to the present invention, a work coil is arranged on the non-heated object side of a nonmagnetic plate, and a ferrite core is inserted into a central space of the coil. A magnetic flux path is secured in the center of the work coil by a ferrite core. A plurality of ferrite cores are radially arranged on the side of the work coil opposite to the object to be heated, the base of the ferrite core. The ferrite core is connected to the non-heated object side, and the distal end is connected to the main ferrite core.The electromagnetic induction heating coil according to the first aspect of the present invention is arranged with a copper pipe along the outer peripheral surface of the ferrite core. The coil for electromagnetic induction heating according to the first or second aspect of the present invention, wherein a slit is interposed in the pipe, a copper plate ring is disposed on the side of the ferrite core to be heated, and the inner periphery of the ring is formed by the addition of the copper pipe. The coil for electromagnetic induction heating according to any one of the first, second, and third aspects, wherein the coil is arranged on the object side and a slit is interposed between the ring and a space surrounded by the copper plate ring from an outer periphery of the copper pipe. The electromagnetic induction heating coil according to the third or fourth aspect of the present invention is configured by winding a coil wire.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A work coil 2 is formed by winding a coil wire 2 'in a single layer while leaving a space s in the center on the lower surface of an inorganic non-magnetic material 1, for example, a heat-resistant glass plate, and the current is conducted. The generated magnetic flux 5 concentrates on the ferrite core 4 through the plurality of radial ferrite cores 6 from the main ferrite core 3 in contact with the object to be heated,
Of the main ferrite core 3 from the outer peripheral portion of the pan 9 to the outer end of the main ferrite core 3.

In the central space s of the work coil 2, the magnetic flux passes through the radial ferrite core 6 and concentrates on the ferrite core core 4 at the center by the copper pipe 7. Due to 8, the magnetic flux 5 concentrates on the center of the pan 9 along the center line c without being dispersed, and reaches the outer periphery of the pan 9. In the meantime, an eddy current is generated within the thickness of the pan 9 and heat is generated from the center of the pan 9 by the eddy current, so that the bottom of the pan is evenly heated to the outer periphery. In this case, the copper plate ring 8 is used to prevent dispersion of the magnetic flux.
The pot 9 is not directly heated unlike the non-magnetic metal plate 14 of FIGS. Therefore, the current flowing through the copper plate ring 8 is small, the energy loss is small, and the efficiency is good.

Further, the copper pipe 7 and the copper plate ring 8 are provided with slits 7 'and 8', thereby suppressing a rise in temperature and preventing a decrease in thermal efficiency due to heat loss.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A work coil 2 is formed by winding a coil wire 2 'in contact with the bottom surface (non-heated object side) of an inorganic nonmagnetic plate 1 made of heat-resistant glass or the like and leaving a central portion.

One or a plurality of rod-shaped ferrite cores 4 are arranged along a center line c at the center of the work coil 2, and a copper pipe 7 having a slit 7 'interposed on the outer periphery thereof is fitted.

The lower end of the ferrite core 4 is supported by a ferrite base plate 10, and the bases of a plurality of ferrite cores 6 shown in FIG. 9 are radially connected to the ferrite base plate 10 to form an antenna-like ferrite core 6.

The tip of the antenna-like ferrite core 6 is connected to the lower surface of the main ferrite core 3.

The lower end of the copper pipe 7 is supported by the ferrite base plate 10, the upper end thereof is in contact with the lower surface of the non-magnetic member 1, and the inner periphery of the copper plate ring 8 is connected to the outer periphery of the upper end. The upper surface is in contact with the lower surface of the non-magnetic body 1.

Therefore, the coil wire 2 ′ that is in contact with the copper pipe 7 and that is wound between the copper plate ring 8 and the ferrite base plate 10 causes a step in the thickness of the copper plate ring 8 between the coil wire 2 ′ and the work coil 2. .

However, when the coil wire 2 'is not used, there is a space between the copper plate ring 8 and the ferrite base plate 10, as shown in FIG.

The main ferrite core 3 overlaps with the antenna-like ferrite core 6 and is supported on its lower surface by a donut-shaped aluminum plate 11, which is supported by an upright outer circular plate 12 ′ of an aluminum support plate 12.

As shown in FIG. 3, the work coil 2 can be formed flat to be applied to the pan 9 '.

In FIG. 1, reference numeral 11 'denotes an aluminum plate attached to the lower surface of the ferrite base plate 10, reference numerals 13 and 13' denote coil terminals, and reference numeral 15 in FIG.

[0020]

Since the present invention is constructed as described above, FIG.
(b) As shown in the figure, the magnetic flux concentrates at the center of the pan, which can heat the center and uniformly heat the whole induction heating portion of the pan, and also provides an electromagnetic induction heating coil with good thermal efficiency. effective.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view of an electromagnetic induction heating coil of the present invention.

FIG. 2 is a partial longitudinal sectional view showing a state where there is no coil wire in a portion surrounded by a copper pipe, a copper plate ring, and a base plate.

FIG. 3 is a longitudinal sectional view of an electromagnetic induction heating coil for a pan.

FIG. 4 is an overall vertical sectional view of FIG.

FIG. 5 is an overall vertical sectional view of FIG. 2;

FIG. 6 (a) is a plan view of a conventional heating state of a pot.
(b) is a plan view of the heating state of the present invention.

FIG. 7 is an exploded view of FIG.

FIG. 8 is an exploded view of FIG.

FIG. 9 is a plan view taken along the line AA of FIG. 8;

FIG. 10 is a bottom view taken along the line BB in FIG. 8;

FIG. 11 is a longitudinal sectional view of a conventional electromagnetic induction heating coil.

FIG. 12 (a) is an example of a plan view taken along line CC of FIG. 11; (B) The figure is another example of the plan view along the line CC in FIG. 11.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Non-magnetic plate 2 Work coil 2 'Coil wire 3 Main ferrite s Central space 4 Ferrite core 5 Magnetic flux 6 Ferrite core (radial) 7 Copper pipe 7', 8 'slit 8 Copper plate ring

Claims (5)

[Claims] 1. A work coil is arranged on the non-heated object side of a non-magnetic plate, a ferrite core is inserted into a center space of the coil, and a magnetic flux path is secured in the center of the work coil by the ferrite core. A coil for electromagnetic induction heating. 2. A plurality of ferrite cores are radially arranged on the side of the work coil opposite to the object to be heated, the base of the ferrite core is connected to the side of the ferrite core opposite to the object to be heated, and the tip is a main ferrite core. The coil for electromagnetic induction heating according to claim 1, which is connected to a coil. 3. The electromagnetic induction heating coil according to claim 1, wherein a copper pipe is arranged along an outer peripheral surface of the ferrite core, and a slit is interposed in the copper pipe. 4. A copper plate ring is disposed on the heated object side of the ferrite core, an inner periphery of the ring is disposed on the heated object side of the copper pipe, and a slit is interposed in the ring. 4. The coil for electromagnetic induction heating according to any one of items 2 and 3. 5. The electromagnetic induction heating coil according to claim 3, wherein a coil wire is wound from an outer periphery of the copper pipe to a space surrounded by the copper plate ring.