JP2022191528A - High-frequency induction heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate a matching process in accordance with heating conditions when high-frequency induction heating is performed.

SOLUTION: A high-frequency induction heating device 1 includes a power feeding coil 21 connected to a high-frequency oscillator through a matching unit, a power receiving coil 31 provided with a gap from the power feeding coil to which high-frequency power is supplied from the power feeding coil in a non-contact manner, and a heating coil 4 connected to the power receiving coil and capable of induction heating the heated object.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a high frequency induction heating device.

Patent Document 1 describes an induction hardening apparatus. This high-frequency hardening apparatus includes a high-frequency oscillator, a matching section, and a high-frequency heating coil. The matching section has a disk transformer and a matching capacitor.

Japanese Patent No. 4644380

In order to efficiently send the high-frequency power output from the high-frequency oscillator to the object to be heated, it is required to perform matching processing in the matching unit in accordance with the heating conditions. A conventional high-frequency induction heating apparatus has a problem that such a matching process is complicated.

SUMMARY OF THE INVENTION An object of the present invention is to facilitate matching processing according to heating conditions when performing high-frequency induction heating.

In order to achieve the above object, a high-frequency induction heating apparatus according to the present invention includes: a feed coil connected to a high-frequency oscillator through a matching section; A power receiving coil to which high-frequency power is supplied by a method, and a heating coil connected to the power receiving coil to induction-heat an object to be heated.

According to the present invention, when performing high-frequency induction heating, it is possible to easily perform matching processing according to heating conditions.

1 is a front view of a high frequency induction heating device; FIG. FIG. 3 is a plan view of a feed coil assembly of the high frequency induction heating device; Fig. 3 is a plan view of a power receiving coil assembly and a heating coil of the high-frequency induction heating device; 5 is a graph showing the relationship between the gap between the power feeding coil and the power receiving coil to which the small heating coil is connected, and the frequency. 5 is a graph showing the relationship between the gap between the power feeding coil and the power receiving coil to which the medium-sized heating coil is connected, and the frequency. 4 is a graph showing the relationship between the gap between the power feeding coil and the power receiving coil to which the large heating coil is connected, and the frequency. 4 is a graph showing the relationship between the size of the heating coil, the gap between the power feeding coil and the power receiving coil, and the frequency.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the illustrated embodiments. However, the present invention is not limited by the embodiments described below.

1 to 3 show a high-frequency induction heating device 1. FIG. A high-frequency induction heating device 1 includes a power supply coil assembly 2 , a power reception coil assembly 3 and a heating coil 4 . Moreover, the high-frequency induction heating device 1
also has a high-frequency oscillator and a matching section (not shown). The matching section has a transformer and a capacitor.

The feed coil assembly 2 has a feed coil 21 . The feeding coil 21 includes a feeding coil body portion 21a formed by bending a square pipe into a substantially ring shape, and a feeding coil body portion 21a.
Extending portions 21 formed to extend radially outward from one end and the other end of 1a, respectively
b. The extending portion 21b is connected to the high frequency oscillator through the matching portion. The square pipe can be made of copper.

The receiving coil assembly 3 has a receiving coil 31 . The power receiving coil 31 includes a power receiving coil main body portion 31a formed by bending a square pipe into a substantially ring shape, and a power receiving coil main body portion 31a.
Extending portions 31 formed to extend radially outward from one end and the other end of 1a, respectively
b. The square pipe can be made of copper.

The feeding coil body portion 21a and the receiving coil body portion 31a are substantially equal in size. The feeding coil main body portion 21a and the receiving coil main body portion 31a are arranged coaxially with each other with a gap G in the axial direction. This gap G is adjustable. Illustration of a mechanism for supporting the feeding coil main body portion 21a and the receiving coil main body portion 31a is omitted.

The feeding coil assembly 2 also has a core 22 that covers the periphery of the feeding coil main body 21a except for the portion facing the receiving coil main body 31a so as not to interfere with the extension 21b.
In addition, the power receiving coil assembly 3 has the power feeding coil main body 21 around the power receiving coil main body 31a.
It also has a core 32 excluding the portion facing a and covering the extending portion 31b so as not to interfere with it. The cores 22 and 32 are insulated so that they are not electrically connected to the power feeding coil 21 and the power receiving coil 31 .

The heating coil 4 is connected to the power receiving coil 31 through the extending portion 31b. The heating coil 4 is formed by bending a square pipe into a substantially ring shape, and both ends thereof are connected to the extending portions 31b. The square pipe can be made of copper. The heating coil 4 can be replaced with another heating coil according to the size of the object (not shown) to be heated. At this time, the combination of the power receiving coil 31 and the heating coil 4 can be replaced with another combination of the power receiving coil and the heating coil without replacing the power feeding coil 21 .

Since the feeding coil main body 21a, the receiving coil 31a, and the heating coil 4 are formed of square pipes having a hollow cross-sectional structure, cooling water can flow inside them.

In the high-frequency induction heating device 1 as described above, high-frequency power is supplied from the high-frequency oscillator to the feeding coil main body 21a through the matching portion and the extension portion 21b. The power feeding coil main body 21a supplies the high frequency power supplied from the high frequency oscillator to the power receiving coil main body 3 in a non-contact manner.
Send to 1a. The power receiving coil body portion 31a sends high-frequency power supplied from the power feeding coil body portion 21a to the heating coil 4 through the extension portion 31b. Then, the object to be heated is induction-heated by the heating coil 4 .

As described above, in the high-frequency induction heating device 1, when high-frequency power is sent from the high-frequency oscillator to the heating coil 4, contactless power supply is performed from the power supply coil to the power reception coil. According to the high-frequency induction heating device 1, by adjusting the gap G between the power feeding coil 21 and the power receiving coil 31, it is possible to perform frequency matching processing that matches the heating conditions.

FIG. 4 shows the relationship between the gap and the frequency when using a small heating coil (inner diameter 40 mm). The horizontal axis is the heating time (unit: seconds), and the vertical axis is the frequency (unit: kHz) of the high-frequency power output from the high-frequency oscillator. When the gap is 1 mm, the frequency is about 9.1 kHz except immediately after the start of heating and just before the end of heating. Similarly, when the gap is 2 mm, the frequency is about 8.7 kHz, and when the gap is 4 mm, the frequency is about 8.1 kHz.

FIG. 5 shows the relationship between the gap and the frequency when using a medium-sized heating coil (inner diameter 60 mm). The horizontal axis is the heating time (unit: seconds), and the vertical axis is the frequency (unit: kHz) of the high-frequency power output from the high-frequency oscillator. When the gap is 1 mm, the frequency is about 8.5 kHz except immediately after the start of heating and immediately before the end of heating. Similarly, when the gap is 2 mm, the frequency is about 8.1 kHz, and when the gap is 4 mm, the frequency is about 7.7 kHz.

FIG. 6 shows the relationship between the gap and the frequency when using a large heating coil (inner diameter 80 mm). The horizontal axis is the heating time (unit: seconds), and the vertical axis is the frequency (unit: kHz) of the high-frequency power output from the high-frequency oscillator. When the gap is 1 mm, the frequency is about 8.0 kHz except immediately after the start of heating and just before the end of heating. Similarly, when the gap is 2 mm, the frequency is about 7.7 kHz, and when the gap is 4 mm, the frequency is about 7.4 kHz.

From FIGS. 4-6, it can be seen that the frequency decreases as the gap increases, regardless of whether the heating coil is small, medium or large. The frequency of the high-frequency power output from the high-frequency oscillator shown in FIGS. 4 to 6 is equal to the frequency of the high-frequency power supplied to the power receiving coil, and is also the frequency of the high-frequency power supplied to the heating coil. equal.

7 shows a graph of FIG. 4 (small heating coil) with a gap of 4 mm, a graph of FIG. 5 (medium heating coil) with a gap of 2 mm, and FIG. 6 (large heating coil). A graph for a gap of 1 mm is shown together. That is, when the heating coil is small, setting the gap to 4 mm results in a frequency of about 8.1 kHz.
A gap of 2 mm results in a frequency of about 8.1 kHz, and if the heating coil is large, a gap of 1 mm results in a frequency of about 8.0 kHz. Thus, by changing the gap, it is possible to obtain similar frequencies regardless of whether the heating coil used is small, medium or large.

As described above, according to the high-frequency induction heating device 1, by adjusting the gap G between the power feeding coil main body 21a and the power receiving coil main body 31a, it is possible to perform frequency matching processing according to the heating conditions. can.

In conventional high-frequency induction heating devices, when the heating coil is replaced according to the size of the object to be heated (one of the heating conditions), it is necessary to change the taps of the capacitor and the transformer in the matching section. In addition, even with the same object to be heated and the same heating coil, the heating conditions differ depending on the heating part of the object to be heated. Heating is performed using Since it is necessary to prepare multiple matching parts,
The whole device is getting bigger.

On the other hand, according to the high-frequency heating induction device 1, the frequency matching process can be performed relatively easily by adjusting the gap G according to the heating conditions. Furthermore, since only one matching section is required, the size of the entire apparatus can be reduced compared to conventional high-frequency induction heating apparatuses that require a plurality of matching sections.

Further, according to the high-frequency heating induction device 1, it is possible to replace the power receiving coil and the heating coil without replacing the power feeding coil. That is, it is possible to shorten the working time associated with the replacement.

The following notes are disclosed with respect to the embodiments described so far.
[Appendix 1]
a feeding coil connected to the high frequency oscillator through a matching section;
a power receiving coil provided with a gap from the power feeding coil and supplied with high-frequency power from the power feeding coil in a non-contact manner;
A high-frequency induction heating device comprising: a heating coil that is connected to the power receiving coil and induction-heats an object to be heated.
[Appendix 2]
The power feeding coil and the power receiving coil are provided coaxially with the gap in the axial direction,
wherein the gap is adjustable;
The high-frequency induction heating device according to appendix 1.
[Appendix 3]
3. The high-frequency induction heating device according to appendix 1 or 2, wherein the power receiving coil and the heating coil can be replaced with another combination of the power receiving coil and the heating coil.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes are possible based on the technical idea of the present invention.

1 High frequency induction heating device

2 feeding coil assembly 21 feeding coil 21a feeding coil body 21b extension 22 core

3 Power Receiving Coil Assembly 31 Power Receiving Coil 31a Power Receiving Coil Body 31b Extension 32 Core

4 heating coil

G gap

Claims (3)

a feeding coil connected to the high frequency oscillator through a matching section;
a power receiving coil provided with a gap from the power feeding coil and supplied with high-frequency power from the power feeding coil in a non-contact manner;
A high-frequency induction heating device comprising: a heating coil that is connected to the power receiving coil and induction-heats an object to be heated. The power feeding coil and the power receiving coil are provided coaxially with the gap in the axial direction,
wherein the gap is adjustable;
The high-frequency induction heating device according to claim 1. 3. The high-frequency induction heating device according to claim 1, wherein the combination of said power receiving coil and said heating coil can be replaced with another combination of power receiving coil and heating coil.

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