JP2000021558A - Flexible lead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain a voltage drop in a low inductance, and to provide high flexibility by coaxially inserting a central conductor composed of a litz wire into the center of an outside conductor posed of a copper coil, and passing cooling water between the outside conductor and the central conductor. SOLUTION: A central conductor 12 composed of a litz wire is coaxially inserted into the center of an outside conductor 11 composed of a copper coil, and the central conductor 12 is supported in the center of the outside conductor 11 by plural support rings 13 to keep a distance between the outside conductor 11 and the central conductor 12. Cooling waster flows in from a cooling water inlet 18, flows between the outside conductor 11 and the central conductor 12, and flows out of a cooling water outlet 19 to cool the outside conductor 11 and the central conductor 12. Thus, since a distance between the outside conductor 11 and the central conductor 12 can be approached, an inductance can be reduced, weight can be reduced and flexibility can be enhanced since the copper coil is used as the outside conductor 11, and high frequency resistance can be reduced and heating can be restrained since a litz wire is used as the central conductor 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible lead used for an output part of high-frequency induction heating or high-frequency welding.

[0002]

2. Description of the Related Art FIG. 4 shows a configuration of a conventional high frequency induction heating apparatus for induction heating a thin plate, wherein 1 is a high frequency power supply, 2 is a matching capacitor connected in parallel with the high frequency power supply 1, and 3 is an object to be heated. The thin metal plates 4 and 4 are heating coils disposed around the thin plate 3 and need to be adjusted in the direction indicated by the arrow 5. Reference numeral 6 denotes a high-frequency cable for connecting both ends of the high-frequency power supply 1 or the matching capacitor 2 to both ends of the heating coil 4, through which cooling water flows.

FIG. 5 shows a configuration of a conventional high-frequency welding apparatus. A matching capacitor 2 is connected to both ends of a high-frequency power supply 1. The heating coil 4 is a V-shaped part 7 of a welded pipe 7 which is an object to be welded.
The V-shaped part 7a is pressed from both sides by the pressing roller 8. Both ends of the heating coil 4 are connected to the output side of an output current transformer 9, and a flexible lead 1 through which cooling water flows between the matching capacitor 2 and the output current transformer 9.
Connected by 0. However, the flexible lead 10 is used when the heating coil 4 has a large capacity.
When the heating coil 4 has a small capacity, it is connected by an air-cooled copper thin plate laminate, and when the heating coil 4 has a medium capacity, it is connected by a copper coil.

In each of the above-mentioned conventional devices, when connecting between the high-frequency power supply 1 or the matching unit and the output unit,
Since it is necessary to move the output unit side, it is necessary to connect with a flexible one, and use a flexible flexible lead 10, a water-cooled high-frequency cable 6, a copper thin plate laminate, a copper coil, etc. I was

[0005]

However, 50-45
In thin-plate high-frequency heating or high-frequency welding using a high frequency of 0 KHz, a voltage drop due to inductance in a high-frequency power transmission section is a problem. However, in a conventional flexible lead 10 or the like, a distance between a pair of reciprocating members is large. An inductance of about 1 μH was generated per meter, and the voltage drop during that time reached several thousand volts in many places. Therefore, it was conceived to use an existing water-cooled coaxial cable for the transmission path. However, the water-cooled coaxial cable has a complicated structure, a thick sheath and the like, and thus has no flexibility and a heavy weight. Was unsuitable for use in a transmission line.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and is a lead for connecting a high-frequency power supply or a matching section and an output section in high-frequency induction heating or high-frequency welding. It is an object to obtain a flexible lead that can be suppressed and has high flexibility.

[0007]

According to a first aspect of the present invention, there is provided a flexible lead in which a center conductor made of a litz wire is coaxially inserted into the center of an outer conductor made of a copper coiled tube, and the center between the outer conductor and the center conductor. In this case, cooling water is allowed to flow.

[0008] In the flexible lead according to the second aspect, the center conductor formed of a litz wire is formed in a cylindrical shape, and cooling water also flows through the center conductor.

[0009]

Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1A and 1B are a semi-longitudinal sectional view and a cross-sectional view taken along line AA of the flexible lead according to the first embodiment, FIG. 2 is a plan view of a support ring, and 11 is an outer conductor made of a copper coil. And the center is a center conductor 1 made of a litz wire.
2 are inserted coaxially. Litz wire is made by twisting each element wire individually insulated by fluororesin etc.
The skin effect is reduced, and the resistance at high frequencies can be reduced. 13 has an outer periphery in contact with the inner phase of the outer conductor 11,
It is a disc-shaped support ring made of fluororesin with the center conductor 12 inserted through the inner circumference. By providing a plurality of support rings 13, the center conductor 12 is supported at the center of the outer conductor 11, and The distance between the conductors 12 is maintained. 1
3a is a cooling water passage.

A pair of center conductor terminals 15 are attached to both ends of the outer conductor 11 via insulators 14. Both ends of the center conductor 12 are connected to the center conductor terminals 15 through the insulators 14. A pair of outer conductor terminals 17 are attached to the outer periphery of both ends of the outer conductor 11 via conductors 16, and a cooling water inlet 18 and a cooling water outlet 19 are attached to both ends of the outer conductor 11.

In the above configuration, the pair of center conductor terminals 1
4, 5 is connected to one end of the matching capacitor 2 and one end of the heating coil 4, for example, and a pair of outer conductor terminals 17 are connected to the other end of the matching capacitor 2 and the other end of the heating coil 4. In the case of FIG. 5, the terminals 15 and 17 are connected to the matching capacitor 2 and the output current transformer 9. The cooling water flows from the cooling water inlet 18 and the outer conductor 11 and the center conductor 12
And flows out of the cooling water outlet 19 so that each conductor 1
Cool 1,12.

In the first embodiment, the outer conductor 11 and the center conductor 12 are coaxially arranged, and the distance between them is short, so that the inductance can be reduced to 1/10 to 1/15 of the conventional one. Further, since a copper coil is used as the outer conductor 11, the outer conductor 11 can be lightweight and have high flexibility. Also,
Since the litz wire is used as the center conductor 12, the cooling efficiency is poor due to the wire insulation, but the litz wire has a low high-frequency resistance, so that heat generation can be suppressed. Furthermore, if pure water is used as the cooling water, the withstand voltage is improved, and it can be used for a high-voltage circuit. If the ratio between the diameter of the outer conductor 11 and the diameter of the center conductor 12 is constant, the inductance is the same.
It is possible to cope with this by increasing the diameter of the central conductor 12.

Embodiment 2 FIGS. 3 (a) and 3 (b) show a semi-longitudinal front view of a flexible lead according to a second embodiment and a cross-sectional view taken along line BB of FIG.
Reference numeral 20 denotes a cylindrical center conductor made of a litz wire. The cooling water flowing from the cooling water inlet 18 flows between the outer conductor 11 and the center conductor 20 and the center of the center conductor 20 and flows out of the cooling water outlet 19. I do. Other configurations are the same as those of the first embodiment.

In the second embodiment, since the cooling water flows not only between the outer conductor 11 and the center conductor 20, but also at the center of the center conductor 20, the cooling capacity can be improved, and the high voltage, It can handle large currents. Other effects are the same as those of the first embodiment.

[0015]

As described above, according to the first aspect of the present invention, the center conductor made of a litz wire is inserted coaxially into the center of the outer conductor made of a copper coil, and cooling is performed between the outer conductor and the center conductor. Since water flows and the distance between the two conductors is small, the inductance can be greatly reduced, and the voltage drop can be reduced. In addition, since the outer conductor is formed of a copper coil, it is lightweight and can have high flexibility. Furthermore, while cooling water flows between both conductors, heat generation is suppressed by using a litz wire for the center conductor, and the temperature reduction effect can be enhanced.

According to the second aspect, the center conductor is formed in a cylindrical shape, and the cooling water flows also in the center thereof, so that the cooling effect can be enhanced and the temperature reduction effect can be enhanced.

[Brief description of the drawings]

FIG. 1 is a semi-longitudinal sectional view of a flexible lead according to a first embodiment of the present invention and a transverse sectional view taken along line AA of FIG.

FIG. 2 is a plan view of a support ring according to the first embodiment.

FIG. 3 is a semi-longitudinal front view of a flexible lead according to a second embodiment and a cross-sectional view taken along line BB of FIG.

FIG. 4 is a configuration diagram of a conventional high-frequency induction heating device.

FIG. 5 is a configuration diagram of a conventional high-frequency welding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... High frequency power supply 2 ... Matching condenser 4 ... Heating coil 9 ... Output current transformer 11 ... Outer conductor 12, 20 ... Center conductor 18 ... Cooling water inlet 19 ... Cooling water outlet

Claims (2)

[Claims] 1. A lead for connecting a high-frequency power supply or its matching part and an output part in high-frequency induction heating or high-frequency welding, wherein a center conductor made of a litz wire is inserted coaxially through the center of an outer conductor made of a copper coil. A flexible lead, wherein cooling water flows between the outer conductor and the center conductor. 2. The flexible lead according to claim 1, wherein the center conductor made of the litz wire is formed in a cylindrical shape, and cooling water also flows through the center conductor.