JPH0673894U - Connection structure of heating coil in high frequency induction heating device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a heating coil connection structure in a high-frequency induction heating device, which can improve the degree of coupling between a current transformer and a heating coil and obtain sufficient heating efficiency. [Structure] A cylindrical secondary coil (2
The current transformer (2), in which the primary coil (2b) is housed inside a), is pressure-contacted and fixed through an insulating plate (11), one end of which is fixed to the secondary coil of the current transformer and the other. A holder (8) having a pair of copper plates (9, 10) arranged so that their ends project to the outside of one side surface of the housing, and a sandwiching part (14) formed by the copper plates.
And a heating coil (13) inserted and sandwiched between the copper plates, and plate thickness parts (15, 16) are formed at both ends of the sandwiching part of the copper plate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a heating coil connection structure in a high-frequency induction heating device that heats a work by a high-frequency induction current.

[0002]

[Prior art]

 Conventionally, a high-frequency induction heating device has been used when quenching or brazing a work using a high-frequency induction current. This induction heating device has a current transformer used at the final stage of the inverter circuit, and a heating coil of a predetermined shape is connected to the secondary side of this current transformer. Then, a high-frequency current is supplied from the inverter circuit to this heating coil to heat the work placed in the vicinity of the heating coil. As shown in FIG. 5, this heating coil has a pair of flat copper plates 52, 53 pressed and fixed via an insulating plate 51, and these copper plates 52, 53 are projected to the front side of the housing. It is attached by being sandwiched by a holder 56 composed of a pair of copper plates 54, 55.

[0003]

[Problems to be solved by the device]

 However, this heating coil connection structure has a problem that the coupling efficiency between the current transformer and the heating coil is not sufficient, resulting in poor heating efficiency. That is, a high-frequency large current flows through the inverter circuit of the high-frequency induction heating device, and in particular, the coupling degree between the current transformer and the heating coil, which is the final stage of the current, greatly affects the heating efficiency. However, in the conventional connection portion between the current transformer and the coil, since the copper plates 52 and 53 of the coil are simply sandwiched between the flat copper plates 54 and 55 of the holder, the conductor resistance or the like causes power loss. It tends to occur, the output characteristics deteriorate, and the heating efficiency deteriorates.

The present invention has been made in view of the above circumstances, and improves the degree of coupling between the current transformer and the heating coil, so that the heating coil can be connected in a high-frequency induction heating device with sufficient heating efficiency. It is intended to provide a partial structure.

[0005]

[Means for Solving the Problems]

 In order to achieve such an object, the connecting part structure according to claim 1 is arranged in a housing, and a current transformer in which a primary coil is housed and arranged in a cylindrical secondary coil, and a pressure contact via an insulating plate. A holder having a pair of copper plates, which are fixed and whose one end is fixed to the secondary coil of the current transformer and whose other end projects to the outside of one side surface of the housing, and a sandwiching part formed by the copper plates. And a heating coil inserted and sandwiched between the copper plate and the copper plate, and plate thickness portions are formed at both ends of the sandwiching portion of the copper plate. The connecting portion structure according to claim 2 is characterized in that the plate thickness portion is integrally formed with the copper plate, and the connecting portion structure according to claim 3 is such that the plate thickness portion is separate from the copper plate. It is characterized by being formed of a copper plate.

[0006]

[Action]

 First, according to the connecting part structure of claim 1, the conductor resistance of the holder is reduced by the plate thickness parts at both ends of the clamping part for clamping the heating coil, and the plate thickness part acts as a kind of core. , Absorbs the magnetic flux due to the large current flowing through the copper plate of the heating coil. As a result, the degree of coupling between the current transformer and the heating coil is increased, and sufficient heating efficiency can be obtained.

According to the connection portion structure of the second aspect, the contact resistance between the copper plates can be further reduced by integrally forming the thick plate portion with the copper plate of the holder. In the partial structure, the plate thickness portion formed separately can be changed to an appropriate thickness and can be applied to heating coils of various forms.

[0008]

【Example】

 An embodiment of the present invention will be described below in detail with reference to the drawings. 1 to 3 show a connection structure according to the present invention. In FIG. 1, a current transformer 2 is arranged on the front surface of the induction heating device 1. The current transformer 2 has a secondary coil 2a made of a cylindrical copper plate and a primary coil 2b wound around a copper pipe and housed in the secondary coil 2a. The plate is provided on the bottom plate 1a of the induction heating device. It is fixed via 3, the columns 4, 5 and the bake plates 6, 7.

A holder 8 is fixed to the outer surface of the secondary coil 2 a of the current transformer 2. As shown in FIGS. 2 and 3, the holder 8 has a pair of copper plates 9 and 10 whose one end is brazed and fixed to the secondary coil 2 a. The copper plates 9 and 10 are connected via an insulating plate 11. It is pressed and fixed by a screw 12 of a plastic. Further, the copper plates 9 and 10 have step portions 9a and 10a in their central portions, and the heating coil 13 is inserted and clamped by the step portions 9a and 10a when the copper plates 9 and 10 are pressed and fixed. The sandwiched portion 14 is formed. Then, plate thickness portions 15 and 16 (see FIG. 3) are formed at the upper and lower ends of the sandwiching portion 14 of the copper plates 9 and 10, respectively. The insulating plate 11 is interposed between the plate thickness portions 15 and 16.

Cooling pipes 17 and 18 are brazed and fixed to the outer surfaces of the copper plates 9 and 10. One ends of the cooling pipes 17 and 18 are attached to the outer surface of the secondary coil 2 a of the current transformer 2. It is fixed to the fixed cooling pipe 19. Further, hose connectors 20 and 21 are fixed to the other ends of the cooling pipes 17 and 18, respectively. The copper plates 9 and 10 are arranged such that the other ends thereof project outside the front cover 1b of the induction heating device 1 by a predetermined length.

The heating coil 13 to be inserted into the holding portion 14 of the holder 8 has a pair of flat plate-shaped copper plates 24 and 25, and the copper plates 24 and 25 are connected via an insulating plate 26 to a plastic screw 27. It is fixed by pressure. Cooling pipes 28 and 29 are brazed and fixed to the outer surfaces of the copper plates 24 and 25, and hose connectors 30 and 31 are fixed to one ends of the pipes 28 and 29. A coil 32 formed by bending a copper pipe into a predetermined shape is fixed to the other ends of the cooling pipes 28 and 29.

As shown in FIG. 2, the hose connectors 20 and 21 and the hose connectors 30 and 31 are connected by hoses 33 and 34, respectively, so that the cooling pipe 19, the cooling pipe 17, the hose 33, and the cooling pipe 28 are connected. The coil 32, the cooling pipe 29, the hose 34, and the cooling pipe 18 communicate with each other, and the cooling water is circulated and supplied during heating.

Next, a method of connecting the heating coil 13 to the holder 8 will be described. First, the thicknesses t1 (see FIG. 3) of the respective thicknesses of the copper plates 24, 25 and the insulating plate 26 of the heating coil 13 fixed by press contact are set to be slightly larger than the width t2 of the holding portion 14 of the holder 8. And set with screws 27. Then, the copper plates 24 and 25 on the side opposite to the coil 32 of the heating coil 13 are inserted into the holding portion 14 of the holder 8. As a result, the copper plates 9 and 24 and the copper plates 10 and 25 are in contact with each other and electrically connected, and the heating coil 13 is connected to the secondary side of the current transformer 2.

Then, in this state, an inverter circuit (not shown) operates and a high-frequency large current is supplied to the heating coil via the current transformer 2. A work (not shown) arranged in proximity to the heating coil 13 is induction-heated by the induced conductive flow of the current, and for example, brazing is performed.

As described above, according to the above-described embodiment, since the plate thickness portions 15 and 16 are provided at both ends of the pair of copper plates 9 and 10 of the holder 8, the conductor resistance of the copper plates 9 and 10 can be reduced. Wear. Further, since the heating coil 13 is inserted and sandwiched in the sandwiching portion 14 formed inside the plate thickness portions 15 and 16, magnetic flux due to the current flowing through the copper plates 24 and 25 of the heating coil 13 is generated. Can be absorbed at 16. As a result, the power loss due to the joining of the holder 8 and the heating coil 13 can be reduced, the output characteristics can be improved, and the heating efficiency can be improved.

In the above-mentioned embodiment, the plate thickness parts 15 and 16 are integrally formed at both ends of the copper plates 9 and 10 of the holder 8. However, as shown in FIG. 4, the plate thickness part is separated from the copper plate. It may be formed in. That is, the holder 38 has flat plate-shaped copper plates 39 and 40, and narrow flat plate-shaped copper plates 42 and 43 are arranged at both ends of the copper plate with an insulating plate 41 interposed therebetween. Then, these are pressure-contacted and fixed by the screw 44, and the holding portion 45 is formed in the central portion of the holder 38. Even with this structure, the same effects as those of the above-described embodiment can be obtained, and by adjusting the plate thickness of the copper plates 42 and 43, it is possible to adapt to heating coils of various plate thicknesses. The property is improved.

The shapes and configurations of the current transformer, the holder, the heating coil, and the arrangement of the cooling pipes in the above embodiment are merely examples, and various modifications can be made without departing from the scope of the present invention. Needless to say.

[0018]

[Effect of device]

 As described in detail above, according to the heating coil connection structure in the high-frequency induction heating device of the present invention, the coupling degree between the current transformer and the heating coil is improved, and sufficient heating efficiency can be obtained.

[Brief description of drawings]

FIG. 1 is a side view of a connection structure according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a sectional view of the same main part.

FIG. 4 is a cross-sectional view of a main part showing another embodiment of the present invention.

FIG. 5 is a sectional view of a main part showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Induction heating device 2 Current transformer 2a Secondary coil 2b Primary coil 8 Holder 9, 10 Copper plate 11 Insulation plate 13 Heating coil 14 Clamping part 15, 16 Plate thickness part 32 Coil

Claims (3)

[Scope of utility model registration request] 1. A current transformer, which is disposed in a housing and has a primary coil housed in a cylindrical secondary coil, and is pressure-contacted and fixed via an insulating plate to the secondary coil of the current transformer. A holder having a pair of copper plates arranged such that one end is fixed and the other end protruding to the outside of one side surface of the housing; and a heating coil inserted and sandwiched in a sandwiching portion formed by the copper plates. A structure for connecting a heating coil in a high-frequency induction heating device, characterized in that a plate thickness part is formed at both ends of the sandwiching part of the copper plate. 2. The heating coil connecting portion structure in the high frequency induction heating device according to claim 1, wherein the thick plate portion is integrally formed with the copper plate. 3. The heating coil connecting portion structure in a high frequency induction heating apparatus according to claim 1, wherein the thick plate portion is formed of a copper plate which is separate from the copper plate.