JPH10270160A - Induction heating coil device and its manufacturing method - Google Patents

Abstract

(57) [Problem] To provide a conventional induction heating coil device, it is necessary to mix a sufficient amount of magnetic powder in a heat-resistant synthetic resin material of a coil case. There are problems that the coil case becomes brittle and difficult to handle, and that the processing cost is high. SOLUTION: A magnet 17 is built in a male mold 16 or a female mold 18 of a mold for molding a coil case 9 on which an induction heating coil 11 is placed, and a molten heat-resistant resin obtained by mixing a magnetic powder 10 in the mold. When the magnetic powder 10 was filled, the magnetic powder 10 was attracted by the magnet and was unevenly distributed on one surface of the coil case 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an induction heating coil device used for an induction heating type electric rice cooker or the like.

[0002]

2. Description of the Related Art In recent years, there has been proposed an electric rice cooker incorporating an induction heating method as a heating source for the purpose of cooking delicious rice. FIG. 30 and FIG.
This is an induction heating coil device used for the conventional electric rice cooker shown in -106134.

[0003] In the figure, reference numeral 41 denotes a pot bottom shape for inductively heating an inner rice cooker (not shown) which is provided inside a main body of an electric rice cooker and is made of a material having a magnetic material and having good heat conductivity. The induction heating coil device 42 has the device 41, and a pot bottom-shaped coil case formed by mixing a heat-resistant synthetic resin with a magnetic powder 43 such as a ferrite powder of a high magnetic material, and 42a A coil mounting portion formed on the inner surface of the side wall portion of the coil case 42, 42b is a coil mounting portion also formed on the inner surface of the bottom wall portion, and 42c is provided for detecting the temperature of the inner pot provided at the center of the bottom wall portion of the coil case 42. This is an opening for inserting a temperature sensor (not shown).

As shown in FIG. 31, reference numeral 44 denotes an induction heating coil composed of an outer peripheral coil portion 44a and an inner peripheral coil portion 44b formed by appropriately winding a wire such as a copper wire in a spiral shape. A coil mounting portion 42a in which a side coil portion 44a is formed on an inner surface of a side wall portion of the coil case 42, and a coil mounting portion 42b in which an inner circumferential side coil portion 44b is formed on an inner surface of a bottom wall portion.
Respectively.

[0005] The conventional induction heating coil device 41 used in the induction heating type electric rice cooker and the like configured as described above includes:
When the power supply is turned on and the induction heating coil 44 is energized, a high frequency power supply is applied to the induction heating coil 44, and a magnetic force is generated.
Girl heat is generated by an eddy current in an inner rice cooker (not shown) mounted on the upper portion of the induction heating coil device 41, and the magnetic material portion of the inner cooker generates heat to heat the entire inner cooker.

At this time, the coil case 42 itself mixed with the magnetic powder 43 functions as a magnetic shield device, thereby preventing magnetic leakage outside the inner pan. Therefore, the magnetic force is efficiently propagated to the inner pot, and the heating loss is reduced.

[0007]

The conventional induction heating coil device used for the induction heating type electric rice cooker as described above requires the coil case 42 to exhibit a sufficient function as a magnetic shield device. It was necessary to mix a sufficient amount of magnetic powder in the heat-resistant synthetic resin material. Therefore,
When molding the coil case 42, the molten resin is filled with a large amount of metal powder (magnetic powder), so that it is difficult to select the material of a molding die, and the inflow speed of the resin is slow and the molding time is increased. The problem that cost became high occurred.

Further, as the filling amount of the metal powder (magnetic powder) increases, the coil case becomes brittle, and the coil case is taken out of the mold, assembled into an induction heating coil, or to a rice cooker body of an induction heating coil device. There has also been a problem in that, if care is not taken when handling the device, cracks, breakage, etc. may occur.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and provides an induction heating coil device which is excellent in manufacturability and handleability, can be constructed at low cost, and has a high magnetic shielding performance with a small amount of magnetic material. It is another object of the present invention to provide a manufacturing method thereof.

[0010]

According to a first aspect of the present invention, there is provided an induction heating coil device including a coil for induction heating and a coil case made of a mixed material of a heat-resistant resin and magnetic powder and on which the coil is mounted. The magnetic powder is unevenly distributed on the surface of the coil case on which the coil is mounted or on the surface opposite thereto.

[0011] An induction heating coil device according to a second aspect of the present invention comprises:
In the first invention, the magnetic powder is unevenly distributed in a portion facing the induction heating coil.

An induction heating coil device according to a third aspect of the present invention
A coil for induction heating and a coil case made of a mixed material of heat-resistant resin and magnetic powder are provided, and the coil and the coil case are integrally formed, and the surface of the coil is exposed on the surface of the coil case. Things.

[0013] The induction heating coil device according to a fourth aspect of the present invention comprises:
In the third invention, the magnetic powder is unevenly distributed on the surface of the coil case on which the coil is not provided.

An induction heating coil device according to a fifth aspect of the present invention comprises:
It comprises a coil holder made of a non-magnetic heat-resistant resin integrally formed with an induction heating coil, and a coil case made of a mixed material of a heat-resistant resin and a magnetic powder and integrally formed with the coil holder.

A method of manufacturing an induction heating coil device according to a sixth invention is a method of manufacturing an induction heating coil device comprising a coil for induction heating and a coil case for mounting the coil. A female mold with a built-in magnet is filled with a molten heat-resistant resin mixed with magnetic powder, the heat-resistant resin is cooled and solidified to form the coil case, and the coil is mounted on the formed coil case. Is placed.

According to a seventh aspect of the present invention, there is provided a coil case manufacturing apparatus for an induction heating coil device, comprising an induction heating coil and a coil case made of a mixed material of heat-resistant resin and magnetic powder, on which the coil is mounted. A coil case manufacturing device for a heating coil device, comprising a male mold and a female mold that form a cavity having the same shape as the coil case during polymerization, and a magnet built in the male mold or the female mold along the cavity. It was done.

According to an eighth aspect of the present invention, there is provided a method of manufacturing an induction heating coil device including a coil for induction heating and a coil case for mounting the coil. A female mold containing the same pseudo-induction heating coil as the coil is filled with a molten heat-resistant resin mixed with magnetic powder in a mold, and at the time of filling, the pseudo-induction heating coil is energized to fill the filled heat-resistant resin. Is cooled and solidified to form the coil case, and the coil is mounted on the formed coil case.

A method for manufacturing an induction heating coil device according to a ninth invention is a method for manufacturing an induction heating coil device including an induction heating coil and a coil case made of a mixed material of a heat-resistant resin and magnetic powder. Then, the coil is previously attached to the male mold of a mold composed of a male mold and a female mold, and the mold is filled with a molten heat-resistant resin mixed with magnetic powder, and the coil and the coil case are integrally formed. Is what you do.

A method of manufacturing an induction heating coil device according to a tenth aspect of the present invention is the method according to the ninth aspect, wherein a concave portion is formed in the male mold, and the coil is mounted in the concave portion.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 to 5 show a first embodiment of the present invention. In the figure, reference numeral 1 denotes an induction heating type electric rice cooker equipped with the induction heating coil device according to the present embodiment, 1a denotes an upper case constituting the main body 1, 1b denotes a lower case, and 1c denotes a lower surface of the lower case 1b. The lid 2 covers the upper opening of the main body 1 so that it can be opened and closed, 3 is a hinge, 4 is a latch, 5 is a heat-resistant synthetic resin housed in the main body 1 and has a substantially pot bottom shape. Molded inner pot storage stand,
Numeral 6 stands upright above the inner pan storage table 5, and a heat shield plate formed of an aluminum plate or the like, and 7 is placed on the inner pan storage table 5 and stores rice for cooking rice and water. It is an inner pot.
The inner pan 7 is made of a magnetic material such as a stainless steel plate on the outer surface, and a non-magnetic metal plate with good heat conductivity such as an aluminum plate on the inner surface. It is composed of

Reference numeral 8 denotes a pan-bottom induction heating coil device provided at a distance from the inner pan storage table 5. The pan-bottom-shaped coil case 9 is provided on the inner surface side of the coil case 9. And an induction heating coil 11 formed by spirally winding the desired number. Coil case 9
Is composed of a material obtained by mixing a heat-resistant synthetic resin and a magnetic powder such as a ferrite powder.
As shown in FIG. 2, the outer coil portion 11a and the inner coil portion 1
1b has a double ring structure.

A temperature sensor 12 is provided so as to contact the center of the bottom of the inner pan 7 and detect the temperature of the inner pan 7, and is provided so as to be vertically movable within the opening 9c of the coil case 9. 13 is a control board provided below the induction heating coil device 8 and provided with various control elements for controlling the rice cooking operation;
Is an operation panel section provided on the control board 13 for externally operating various information such as rice cooking, and 15 is a code reel having a power plug.

FIG. 3 is a sectional view of the coil case 9 of the induction heating coil device 8. 3, reference numeral 9a denotes a coil mounting portion formed on the inner surface of the side wall of the coil case 9, 9b denotes a coil mounting portion formed on the inner surface of the bottom wall, and 9c denotes an opening formed in the center of the bottom wall of the coil case 9. Reference numeral 10 denotes a magnetic powder such as a ferrite powder mixed with a heat-resistant synthetic resin, which is unevenly distributed on the inner surface side of the coil case 9 as shown in FIG.

FIG. 4 shows an induction heating coil 1 in a coil case 9.
FIG. 2 is a cross-sectional view of a state where the device 1 is placed. As shown in the figure, an outer coil portion 11a of the induction heating coil 11 is provided on a coil mounting portion 9a formed on a side wall of the coil case 9, and an inner coil portion 11b is provided on a coil mounting portion 9b formed on a bottom wall of the coil case 9. Are placed and stored respectively.

Next, a method of manufacturing the coil case 9 constituting the induction heating coil device 8 will be described. FIG. 5 is a sectional view of a mold for manufacturing the coil case 9. In the figure, reference numeral 16 denotes a male mold (hereinafter, referred to as a male mold), which includes 16a to 16d described later. 16a is an injection molding machine (not shown) for molding the coil case 9.
Male mold A (hereinafter referred to as male mold A) to be installed and used in
Reference numeral 16b denotes a male mold B (hereinafter referred to as male mold B) which is provided at the tip of the male mold A16a and is provided by overlapping with the male mold A16a for embedding a magnet described later. A16a, a runner formed at the center of the male mold B16b to allow the molten synthetic resin to flow, 16d is formed at the tip of this runner 16c, and fills a cavity described later with the molten synthetic resin flowing from the runner 16c. Gate provided for the purpose. 17 is male A16a
And a permanent magnet or an electromagnet. The male mold 16 is fixed in the injection molding machine.

Reference numeral 18 denotes a female mold (hereinafter referred to as a female mold) installed below the male mold 16 and is configured to move downward. The male mold A16a, the male mold B16b, and the female mold 18 are formed of a material through which the magnetic force of the magnet 17 passes, for example, a nonmagnetic material such as a beryllium copper alloy. 19
Is a cavity formed when the male mold 16 and the female mold 18 are polymerized. The cavity is filled with a molten synthetic resin and cooled to form the coil case 9 having a desired shape.

The male mold 16 and the female mold 18 having the above configuration are installed in an injection molding machine, and a molten synthetic resin mixed with a magnetic powder 10 made of a high magnetic material such as a ferrite powder is mixed with the runner 1.
It is injected into the cavity 19 through 6c and the gate 16d, and then cooled to form the coil case 9 having a desired shape. At the time of this injection molding, male molds A16a, B16b
Due to the magnetic force (attraction force) of the magnet 17 embedded in the cavity, only the magnetic powder 10 of the molten synthetic resin in the cavity 19 is attracted to the male mold 16 side. Therefore, the coil case 9 that has been solidified through the cooling step and has been removed by moving the female mold 18 downward has the magnetic powder 10 unevenly distributed on the inner surface side (FIG. 3).

In the coil case 9 filled with the magnetic powder 10 over the entire inner surface as described above, the induction heating coils 11 having the double-ring structure shown in FIG.
If it is placed and fixed on a and 9b, the induction heating coil device 8 having the magnetic powder 10, that is, the magnetic shield device on the back surface of the induction heating coil 11, is completed (FIG. 4).

According to the first embodiment, a magnetic shielding effect can be obtained with a small amount of magnetic powder, and magnetic leakage to the outside can be prevented. Further, in the coil case, since the magnetic powder is unevenly distributed on the surface and most of the components are made of synthetic resin, they are not brittle and have high strength. Further, since the inflow speed of the molten resin is increased, the processing time can be reduced and the processing cost can be reduced.

Embodiment 2 FIG. 6 to 8 show a second embodiment of the present invention. In the second embodiment, the magnetic powder 10 is unevenly distributed on the outer surface side of the coil case 9 as shown in FIGS. In the drawings, the same components as those in the first embodiment are denoted by the same reference numerals, and the description is omitted.

FIG. 8 shows the coil case 9 shown in FIGS.
It is sectional drawing of the metal mold | die which manufactures. In the figure, reference numeral 16 denotes a male mold (hereinafter referred to as a male mold) installed in the injection molding machine, which is used for molding the coil case 9 and is fixed in the injection molding machine. Reference numeral 16c denotes a runner which is opened at a substantially central portion of the male mold 16 and in which molten synthetic resin flows, and 16d is a gate formed at the tip of the runner 16c to fill the cavity 19 with the molten resin.

Numeral 18 denotes a female mold disposed below the male mold 16 and configured to move downward (hereinafter referred to as a female mold).
And the female mold A18a and the female mold B1
8b is formed by superposing and fixing a magnet 17 having a substantially pan-bottom shape. The female mold A18a and the female mold B18b are made of a non-magnetic material that transmits magnetic force, for example, beryllium copper alloy. Reference numeral 19 denotes a cavity formed when the male mold 16 and the female mold 18 are superimposed. The cavity 19 is filled with a molten synthetic resin and cooled to form the coil case 9 having a desired shape.

The male mold 16 and the female mold 18 having the above configuration are installed in an injection molding machine, and the molten resin mixed with the magnetic powder 10 is injected under pressure from the runner 16c, and is filled into the cavity 19 from the gate 16d. . Then mold 16,
When the molten resin 18 is cooled, the molten resin is solidified in the cavity 19, and the female die 18 is moved downward to open the male die 16 and the female die 18, a finished product of the coil case 9 having a desired shape is taken out. . At the time of this injection molding, the magnetic powder 10 mixed with the molten resin in the cavity 19 is attracted to the female mold 18 by receiving the magnetic force of the magnet 17 embedded in the female mold 18. Accordingly, the magnetic powder 10 is unevenly distributed on the outer surface side of the coil case 9 which has been cooled, solidified and taken out (FIG. 6).

A double-ring induction heating coil 11 shown in FIG. 2 is placed in a coil case 9 filled with magnetic powder 10 over the entire outer surface of the coil mounting portion 9a, 9b.
Then, the induction heating coil device 8 having the magnetic powder 10, that is, the magnetic shield device on the back surface of the induction heating coil 11 is completed (FIG. 7).

Also in the second embodiment, similar to the first embodiment, effects such as a magnetic shielding effect can be obtained with a small amount of magnetic powder. In the above-described first or second embodiment, if the magnet 17 incorporated in the mold is formed in a shape corresponding to the portion where the induction heating coil 11 is mounted, the induction heating The magnetic powder 10 is unevenly distributed only in the portion facing the coil 11, and a magnetic shielding effect can be obtained with a smaller amount of magnetic powder.

Embodiment 3 9 to 11 show a third embodiment of the present invention. FIG. 9 shows the third embodiment.
1 is a sectional view of a mold for manufacturing the coil case 9 in FIG.
0 is a cross-sectional view of the coil case 9 manufactured by the mold, and FIG. 11 is a perspective view thereof.

In FIG. 9, reference numeral 16 denotes a male type, which is made of a magnetically permeable material such as a beryllium copper alloy. Reference numeral 16c denotes a runner into which the synthetic resin flows, and 16d denotes a gate formed at the tip of the runner 16c.
Reference numeral 18 denotes a female mold, and 19 denotes a cavity formed when the male mold 16 and the female mold 18 are polymerized. 20 is an induction heating coil 1 embedded in the male mold 16 and used for the induction heating coil device 8.
This is a pseudo-induction heating coil device configured exactly as in FIG.

The male mold 16 and the female mold 18 are set in an injection molding machine, and a molten synthetic resin obtained by mixing a heat-resistant resin and a magnetic powder 10 such as a ferrite powder is injected from a runner 16c of the male mold 16, and is injected from a gate 16d. Inject into the cavity 19. Thereafter, the mold is cooled to solidify the molten synthetic resin, and the female mold 18 is moved downward to open the male mold 16 and the female mold 18, whereby the coil case 9 having a substantially pan-bottom shape is formed and taken out.

Here, at the same time as the injection of the molten resin, the male mold 16 is formed.
When the pseudo induction heating coil 20 embedded in the inside is energized, a magnetic field is generated in the male mold 16, and the magnetic powder 10 mixed with the resin in the cavity 19 by the action of the lines of magnetic force causes the magnetic powder 10 in the cavity 19 along the magnetic field. It is arranged by suction on the upper surface side.
Accordingly, the removed coil case 9 has the magnetic powder 10 unevenly distributed on the inner surface thereof in the same arrangement as the magnetic field generated by the induction heating coil 11 (FIGS. 10 and 1).
1).

If the induction heating coil 11 is arranged and fixed on the inner surface side of the coil case 9, a magnetic shield device using the magnetic powder 10 is arranged on the back surface, and the magnetic powder 10 is arranged along the magnetic field generated by the induction heating coil 11. The completed induction heating coil device 8 is completed.

According to the third embodiment, it is possible to obtain an induction heating coil device having a magnetic shielding effect with a smaller amount of magnetic powder.

Embodiment 4 12 to 16 show a fourth embodiment of the present invention. FIG. 12 is a sectional view of a mold for manufacturing the induction heating coil device 8 according to the fourth embodiment. In FIG. 12, 16 is a male type, 16c is a runner into which synthetic resin flows, and 16d is a runner 16d.
The gate formed at the tip of c, 18 is a female mold, and 19 is a cavity formed when the male mold 16 and the female mold 18 are superimposed. Here, the induction heating coil 11 which has been wound in advance
Is mounted on the male mold 16 before the male mold 16 is installed in the injection molding machine.

Reference numeral 18c denotes a coil holding projection formed at several places on the female die 18, which protrudes into the cavity 19 so that the induction heating coil 11 attached to the male die 16 can be used to form the male die 16 during molding. The outer coil 11a and the inner coil 11 of the induction heating coil 11
b are respectively provided. FIG. 13 shows a cross-sectional view of a portion of the female die 18 where the coil holding projection 18c is formed.

After the dies 16 and 18 configured as described above are installed in an injection molding machine, as in the above embodiments,
A molten synthetic resin obtained by mixing a heat-resistant resin and a magnetic powder 10 such as a ferrite powder is injected from the runner 16c of the male mold 16 and injected into the cavity 19 from the gate 16d. Thereafter, the mold is cooled to solidify the resin, and the female mold 18 is moved downward to open the male mold 16 and the female mold 18. As shown in the sectional view of FIG. The induction heating coil device 8 to which the induction heating coil 11 is integrally attached is taken out. FIG. 15 shows a cross-sectional view in which a part thereof is enlarged.

As shown in FIG. 14 or FIG. 15, the back and side surfaces of the induction heating coil 11 of the induction heating coil device 8 are surrounded by the magnetic powder 10 and have a function as a magnetic shield device. Further, when the induction heating coil 11 is attached to the male mold 16 and the molten synthetic resin is injected, the molten synthetic resin hardly flows into the male mold 16 side of the induction heating coil 11. The portion is integrally formed in a state of being exposed to the outside, and there is no hindrance to radiation of the lines of magnetic force toward the inner pot 7.

According to the method of manufacturing the induction heating coil device 8 described above, the assembly of the coil case 9 and the induction heating coil 11 is simplified, which contributes to cost reduction and
Since the magnetic shield performance is not impaired and the strength of the coil case is increased, the handleability is excellent when assembling into a rice cooker or the like.

Embodiment 5 16 to 20 show a fifth embodiment of the present invention. FIG. 16 is a sectional view of a mold for manufacturing the induction heating coil device 8 according to the fifth embodiment, FIG. 17 is a sectional view in which a part of FIG. 16 is enlarged, and FIG.
FIG. 17 is an enlarged sectional view of a part of the male mold 16 and the female mold 18 constituting the mold shown in FIG. In each drawing, the same reference numerals are given to the same parts as those in the fourth embodiment, and the description thereof will be omitted.

In the fifth embodiment, as shown in FIG. 18, a recess 16e for attaching the induction heating coil 11 to the male die 16 is formed. Before installing the male mold 16 in the injection molding machine, the completed induction heating coil 11 is attached to the concave portion 16e. And male type 1
6. When the female mold 18 is installed in the molding machine, the induction heating coil 1
1 is supported by a coil holding projection 18c provided on the female die 18, so that the induction heating coil 11 does not fall off during the forming process.

Here, the concave portion 16e is
In accordance with the shape of the male mold 16, the male mold 16 is formed in an annular shape on the entire side surface and the bottom surface, and the depth thereof is set to about half the thickness (wire diameter) of the attached induction heating coil 11. is there. Therefore, it is easy to fix the induction heating coil 11, and when the molten synthetic resin is injected into the cavity 19, there is no possibility that the molten synthetic resin flows into the inner surface side of the induction heating coil 11. Since the thickness is exposed to the outside, the induction heating coil 1
The radiation of the lines of magnetic force from 1 to the inner pan 7 is not hindered.

The injection heating coil device 8 completed by injection molding using the dies 16 and 18 having such a structure, as shown in FIGS. 11 exposes approximately half the thickness of the wire diameter portion to the outside, and uses the remaining half thickness of the coil case 9.
Embedded in the resin and integrally molded. Therefore, the assembly of the coil case 9 and the induction heating coil 11 is simplified, and the radiation of the magnetic field lines from the induction heating coil 11 to the inner pot 7 is not hindered, so that the induction heating performance is not impaired. A coil device is obtained.

Embodiment 6 FIG. 21 to 25 show a sixth embodiment of the present invention. FIG. 21 is a sectional view of a mold for manufacturing the induction heating coil device 8 according to the sixth embodiment, and FIG. FIG. 23 is a cross-sectional view showing a part of the coil device 8 in an enlarged manner. The sixth embodiment is a combination of the second embodiment (FIG. 8) and the fourth embodiment (FIG. 12).

That is, the female die 18 is formed by polymerizing and fixing a substantially pan-bottomed magnet 17 to the female die A 18a and the female die B 18b disposed thereon. In addition, female mold A
18a and the female mold B18b are formed of a non-magnetic material, for example, a magnetically permeable material such as a beryllium copper alloy. Further, the induction heating coil 11 is attached to the male mold 16 before the male mold 16 is installed in the molding machine. When the male mold 16 and the female mold 18 are installed in the molding machine, the coil holding projections 1 provided on the female mold 18 are provided.
8c so that it does not fall off during molding.

According to the mold having such a structure, when the cavity 19 is filled with the molten resin, the magnetic powder 10 mixed with the molten resin is attracted by the magnet 17 built in the female mold 18 so that the cavity 17 is actuated. It is sucked to the outer surface side of 19.
Therefore, the completed induction heating coil device 8 is shown in FIG.
As shown in 2 and 23, the induction heating coil 11 is buried on the inner surface side of the coil case 9 with a part of its surface exposed, and the magnetic powder 10 is unevenly distributed on the outer surface side of the coil case 9.

Therefore, the assembly of the coil case 9 and the induction heating coil 11 is simplified, and the magnetic powder 1
Even if the content of 0 is small, the magnetic shielding property is high. Further, since the magnetic powder 10 for magnetic shielding does not adhere to the surface of the induction heating coil 11, the amount of magnetic radiation to the inner pot 7 does not decrease, and the heating efficiency is improved. Furthermore, since the magnetic powder 10 is gathered on the outer surface side of the coil case 9, the coil case 9 does not become brittle as a whole and has a high strength. I do.

As shown in FIG. 24, if the shape of the magnet 17 embedded in the female die 18 is made to correspond to the shape of the induction heating coil 11 attached to the male die 16, the induction as shown in FIG. Since the magnetic powder 10 is unevenly distributed around the heating coil 11, the magnetic shielding performance is further improved.
Further, the amount of the magnet 17 to be used is small, and an economical mold can be obtained.

Embodiment 7 FIG. 26 to 29 show Embodiment 7 of the present invention. FIG. 26 is a sectional view of a mold for manufacturing the induction heating coil device 8 according to the seventh embodiment. In the figure, 16 is a male mold, 16c is a runner, 16d is a gate, 18 is a female mold, and 19 is a cavity. Yes, it is the same as the above embodiments. Also, 2
Reference numeral 1 denotes a coil holder having a substantially pan bottom shape. As shown in FIG. 27, the induction heating coil 11 is buried by a separately provided injection molding machine (not shown) and a mold (not shown), and is integrally formed. It was done. The coil holder 21 is formed of a heat-resistant synthetic resin, and is not mixed with a magnetic powder 10 such as a ferrite powder.

16f is a recess formed around the male die 16 for mounting the coil holder 21, and 18d is a female die 1
FIG. 28 is an enlarged cross-sectional view of a portion where the recess 16f and the holding projection 18d are formed.

A coil holder 21 integrally formed with the induction heating coil 11 in advance is attached to the concave portion 16f of the male mold 16, and both the molds 16 and 18 are set in an injection molding machine. Thereafter, a molten synthetic resin mixed with the magnetic powder 10 is poured and injection molding is performed. Then, the female mold 18 is moved downward to
6 and 18 are opened, and the coil case 9 molded in the cavity 19 is taken out.

The completed induction heating coil device 8 is shown in FIG.
As shown in (1), the coil holder 21 is integrally embedded on the inner surface side, and has the magnetic powder 10 around the coil holder 21. Therefore, a magnet for sucking the magnetic powder into the mold is not required, and the induction heating coil device can be manufactured easily and inexpensively, and an induction heating coil device that does not impair the magnetic shielding performance with a small amount of magnetic powder can be obtained. In addition, the handleability in assembling is good.

[0060]

According to the induction heating coil device of the first invention, a magnetic shielding effect can be obtained even if the amount of the magnetic powder mixed with the heat-resistant resin is small, and magnetic leakage to the outside can be prevented. In addition, the coil case is not fragile because the metal substance is unevenly distributed on the surface and most of the configuration is made of a synthetic resin, so that the coil case is excellent in handleability in assembling and the like.

According to the induction heating coil device of the second invention, the magnetic powder is unevenly distributed only in the portion facing the coil, so that a magnetic shielding effect can be obtained with a smaller amount of magnetic powder.

According to the induction heating coil device of the third aspect, the assembly of the coil and the coil case is simplified.

According to the induction heating coil device of the fourth invention, the assembly of the coil and the coil case is simplified, the magnetic shielding effect is obtained with a small amount of magnetic powder, the strength is increased, and the surface of the coil is Since the magnetic powder does not adhere, the amount of magnetic radiation to the inner pot does not decrease and the heating efficiency is improved.

According to the induction heating coil device according to the fifth aspect of the present invention, the magnetic shield effect can be obtained with a small amount of magnetic powder, and the strength of the induction heating coil device is increased.

According to the method of manufacturing an induction heating coil device according to the sixth aspect of the invention, the magnetic powder is attracted by the male or female built-in magnet, and the magnetic powder is unevenly distributed on the surface of the coil case. Since an apparatus is obtained, an induction heating coil apparatus having a magnetic shielding effect with a small amount of magnetic powder can be obtained by an easy manufacturing method.

According to the coil case manufacturing apparatus of the induction heating coil device according to the seventh invention, a coil case in which the magnetic powder is unevenly distributed on the surface can be obtained.

According to the method of manufacturing the induction heating coil device according to the eighth aspect of the invention, the magnetic powder is attracted by the pseudo induction heating coil built in the male or female mold, and has the same arrangement as the magnetic field generated by the coil. Since the magnetic powder is unevenly distributed, an induction heating coil device having a magnetic shielding effect can be obtained with a smaller amount of the magnetic powder by an easy manufacturing method.

According to the method of manufacturing an induction heating coil device according to the ninth aspect, the assembly process of the coil and the coil case is simplified, and an induction heating coil device having a magnetic shielding effect can be obtained by an easy manufacturing method.

According to the method of manufacturing an induction heating coil device according to the tenth aspect of the present invention, the process of assembling the coil and the coil case is simplified, and the surface of the coil is reliably exposed outside the coil case. And an induction heating coil device which does not impair the performance of the coil and the magnetic shield performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an induction heating electric rice cooker using an induction heating coil device according to Embodiment 1.

FIG. 2 is a perspective view of an induction heating coil.

FIG. 3 is a longitudinal sectional view of the coil case in the first embodiment.

FIG. 4 is a longitudinal sectional view of the induction heating coil device according to the first embodiment.

FIG. 5 is a longitudinal sectional view of a mold for forming and processing the coil case in the first embodiment.

FIG. 6 is a longitudinal sectional view of a coil case according to a second embodiment.

FIG. 7 is a longitudinal sectional view of an induction heating coil device according to a second embodiment.

FIG. 8 is a longitudinal sectional view of a mold for forming and processing a coil case according to the second embodiment.

FIG. 9 is a longitudinal sectional view of a mold for forming and processing a coil case according to a third embodiment.

FIG. 10 is a longitudinal sectional view of a coil case according to a third embodiment.

FIG. 11 is a perspective view of a coil case according to a third embodiment.

FIG. 12 is a longitudinal sectional view of a mold for forming and processing the induction heating coil device according to the fourth embodiment.

13 is a longitudinal sectional view of the female mold shown in FIG.

FIG. 14 is a longitudinal sectional view of an induction heating coil device according to a fourth embodiment.

15 is an enlarged longitudinal sectional view of a part of the induction heating coil device shown in FIG.

FIG. 16 is a longitudinal sectional view of a mold for forming and processing the induction heating coil device according to the fifth embodiment.

FIG. 17 is an enlarged sectional view of a main part of the mold shown in FIG.

FIG. 18 is a partial sectional view of a male mold and a female mold of the mold shown in FIG.

FIG. 19 is a longitudinal sectional view of the induction heating coil device according to the fifth embodiment.

FIG. 20 is an enlarged longitudinal sectional view of a part of the induction heating coil device shown in FIG. 19;

FIG. 21 is a longitudinal sectional view of a mold for forming and processing the induction heating coil device according to the sixth embodiment.

FIG. 22 is a longitudinal sectional view of the induction heating coil device according to the sixth embodiment.

FIG. 23 is an enlarged longitudinal sectional view of a part of the induction heating coil device shown in FIG. 22;

FIG. 24 is a longitudinal sectional view of a mold for forming and processing an induction heating coil device according to another example of the sixth embodiment.

FIG. 25 is an enlarged longitudinal sectional view of a part of an induction heating coil device according to another example of the sixth embodiment.

FIG. 26 is a vertical sectional view of a mold for forming and processing the induction heating coil device according to the seventh embodiment.

FIG. 27 is a longitudinal sectional view of an induction heating coil and a coil holder according to a seventh embodiment.

FIG. 28 is an enlarged sectional view of a main part of the mold shown in FIG. 26;

FIG. 29 is a longitudinal sectional view of the induction heating coil device in the seventh embodiment.

FIG. 30 is a longitudinal sectional view of a conventional induction heating coil device.

FIG. 31 is a top view of a conventional induction heating coil.

[Explanation of symbols]

8 induction heating coil device, 9 coil case, 10 magnetic powder, 11 induction heating coil, 16 male type, 17 magnet, 18 female type, 19 cavity, 20 pseudo induction heating coil device, 21 coil holder.

Claims (10)

[Claims] 1. A coil for induction heating, and a coil case made of a mixed material of a heat-resistant resin and a magnetic powder, on which the coil is mounted, wherein the coil case has a coil mounting surface or a surface opposite to the coil mounting surface. An induction heating coil device, wherein the magnetic powder is unevenly distributed on a surface side. 2. The induction heating coil device according to claim 1, wherein the magnetic powder is unevenly distributed in a portion facing the induction heating coil. 3. A coil for induction heating, and a coil case made of a mixed material of a heat-resistant resin and a magnetic powder, wherein the coil and the coil case are integrally formed, and a surface of the coil is formed of the coil case. An induction heating coil device which is exposed on the surface. 4. The induction heating coil device according to claim 3, wherein the magnetic powder is unevenly distributed on a surface of the coil case on which the coil is not provided. 5. A coil holder comprising a non-magnetic heat-resistant resin integrally formed with an induction heating coil, and a coil case formed of a mixed material of a heat-resistant resin and magnetic powder and integrally forming the coil holder. Induction heating coil device. 6. A method of manufacturing an induction heating coil device comprising an induction heating coil and a coil case for mounting the coil, wherein the magnetic powder is placed in a mold having a male or female mold with a built-in magnet. Filling the mixed molten heat-resistant resin, cooling and solidifying this heat-resistant resin to form the coil case,
A method for manufacturing an induction heating coil device, comprising mounting the coil on a molded coil case. 7. A coil case manufacturing apparatus for an induction heating coil device comprising: an induction heating coil; and a coil case made of a mixed material of a heat-resistant resin and magnetic powder, and on which the coil is mounted. A coil case manufacturing apparatus for an induction heating coil device, comprising: a male die and a female die forming a cavity having the same shape as a coil case, wherein a magnet is built in the male die or the female die along the cavity. . 8. A method for manufacturing an induction heating coil device comprising a coil for induction heating and a coil case for mounting the coil, wherein the same pseudo induction heating coil as the coil is provided in a male or female type. A built-in mold is filled with the molten heat-resistant resin mixed with the magnetic powder, and at the time of filling, the pseudo induction heating coil is energized, and the filled heat-resistant resin is cooled and solidified to form the coil case. A method for manufacturing an induction heating coil device, comprising mounting the coil in a coil case that has been set. 9. A method of manufacturing an induction heating coil device comprising an induction heating coil and a coil case made of a mixed material of a heat-resistant resin and a magnetic powder, the method comprising: forming a male mold and a female mold. A method for manufacturing an induction heating coil device, comprising: attaching the coil to a male mold in advance, filling the mold with a molten heat-resistant resin mixed with magnetic powder, and integrally molding the coil and the coil case. . 10. The method for manufacturing an induction heating coil device according to claim 9, wherein a concave portion is formed in the male mold, and a coil is attached to the concave portion.