JP5135736B2 - High frequency feeder - Google Patents

Description

  The present invention relates to a high-frequency power supply line that can reduce high-frequency loss due to the skin effect that occurs at high frequencies.

When an alternating current is applied to a conductive wire having a uniform conductivity σ and the frequency ω is increased, a skin effect occurs in which the alternating current concentrates near the surface of the conductive wire. The degree is expressed by skin depth δ. The skin depth δ is expressed by δ = (2 / ωσμ) ^1/2 . Here, ω represents the frequency, and μ represents the magnetic permeability of the conductive wire.

  Therefore, when the frequency ω of the current flowing through the conductive wire is increased, the skin depth δ is decreased. For example, in a conductive wire having a round cross-sectional shape, the electrical resistance increases near the center, and the current does not flow easily. As a result, the electrical resistance of the entire conductive wire is increased. Therefore, the loss due to the increase in electrical resistance due to the skin effect can be remarkably reduced by using a conductive wire having a diameter equal to or smaller than the skin depth δ.

  Conventionally, as shown in, for example, Japanese Patent Laid-Open No. 5-250926 (Patent Document 1), a litz wire obtained by twisting a plurality of subdivided enamel wires to reduce the skin effect has been known. Yes. As shown in FIG. 6, the litz wire has a conductive wire 10 having an enamel coating 20 subdivided at a central position, and a conductive wire 10 having a plurality of similar enamel coatings 20 is arranged around the conductive wire 10. It is configured.

  However, in a high-frequency power supply line using a litz wire obtained by twisting a plurality of subdivided enamel wires, the skin effect can be reduced by reducing the diameter of each conductive wire 10 of the litz wire. However, when the frequency is high, it is necessary to make an extremely fine conductive wire 10 and it is difficult to produce it. Even if an extremely fine single wire can be produced, it is very difficult to handle a stranded wire. There were problems such as difficulty.

  Therefore, conventionally, as shown in Japanese Patent Application Laid-Open No. 9-008076 (Patent Document 2), a high-frequency feed line using a hollow conductive wire having a hollow portion is known. As shown in FIG. 7, the high-frequency power supply line is configured such that a hollow portion 31 is formed inside the conductive wire 30 and an inner peripheral surface 33 is provided, so that a high-frequency current flows only on the outer peripheral surface 32 of the conductive wire 30. In addition, a high-frequency current can also flow through the inner peripheral surface 33 of the conductive wire 30, and a high-frequency current can also flow through the conductive wire 30 that has not previously functioned as a conductor. As a result, it is known that the effective area through which the high-frequency current flows can be increased without increasing the outer diameter of the conductive wire 30.

Here, in the case of a high-frequency power supply line in which the hollow conductive wire 30 is a single wire, for example, if the frequency is 10 kHz and the material is copper, the skin depth δ is 0.6 mm. Therefore, when it is necessary to secure 5.5 mm ² as an effective area through which the high-frequency current flows, the diameter of the high-frequency feed line constituted by the single hollow conductive wire 30 is 13.2 mm.
Japanese Patent Laid-Open No. 5-250926 Japanese Patent Laid-Open No. 9-008076

As shown in FIG. 8, when the hollow conductive wire 30 is composed of seven pieces, if the frequency is 10 kHz, the material is copper, and the effective area is 5.5 mm ² , the hollow conductive wire 30 The diameter is 1.9 mm, and the diameter of the high-frequency power supply line is 5.7 mm plus a peripheral insulator. Accordingly, the outer diameter of the high-frequency power supply line can be made smaller if it is constituted by a plurality of hollow conductive wires 30 than if it is constituted by a single hollow conductive wire 30.

  However, in this high-frequency power supply line, when a plurality of hollow conductive wires 40 are configured, the hollow conductive wires 40a arranged in the periphery do not have a reference position with respect to the hollow conductive wires 40b arranged in the center, and are equal. However, the current density distribution cannot be made uniform, and the skin effect cannot be effectively reduced.

  The present invention was invented in view of the above-mentioned background art, and its purpose is to evenly distribute the current density distribution by efficiently arranging a plurality of conductive wires around the axis, thereby reducing the skin effect efficiently. And it aims at providing the high frequency electric power feeding line which can reduce the increase in an electrical resistance value.

In order to solve the above-described problem, in the invention according to claim 1 of the present application , a plurality of conductive lines including one conductive line and another conductive line arranged around the one conductive line as a center , an insulator, the in the high-frequency power supply lines formed by integrally formed, have a means for placing at equiangular other conductive wire around one of the conductive wire in the center, the said means and said one conductive line A hole having a shape is formed at the center position, and the outer periphery of the hole is formed of an insulator having a plurality of positioning grooves in which other conductive wires are fitted at equal angular pitches. The plurality of conductive wires are coaxial with the conductive wires. Each has one hollow part .

  The invention according to claim 2 of the present application is characterized in that, in the high-frequency power supply line according to claim 1, one conductive wire located in the center has a smaller cross-sectional thickness than other conductive wires arranged around it. .

  The invention according to claim 3 of the present application is characterized in that in the high-frequency power supply line according to claim 1, a plurality of grooves extending in the longitudinal direction are provided on the outer peripheral surface of the conductive wire.

According to a fourth aspect of the present invention, in the high-frequency power supply line according to any one of the first to third aspects, both conductive wires are provided in the hollow portion of the butt joint portion of the conductive wire butt-joined in the longitudinal direction. straddles and both conductive line via a connecting member to fitted in pressure-contact with the inner surface of the conductive wire is characterized by being connected to.

The invention according to claim 5 of the present application is characterized in that in the high-frequency power supply line according to claim 4 , slits extending in the longitudinal direction are provided at both ends of the connection member.

In the high frequency power supply line according to the first aspect of the present invention, depending on the shape of the insulator, one conductive line is arranged at the center position, and the other conductive line is arranged at an equal angle with respect to the center, simply and reliably. As a result, the plurality of conductive lines are evenly arranged with respect to the axial center, and when a high frequency current is passed, the current density distribution becomes uniform, and the skin effect can be effectively reduced. The value can be lowered. In particular, by providing a hollow portion inside the conductive wire, a high-frequency current can also flow through the inner peripheral surface of the conductive wire, so the effective area through which the high-frequency current flows without increasing the outer diameter of the conductive wire. When a high-frequency current is passed through the conductive wire, an increase in current resistance value due to the skin effect can be reduced.

  In the high-frequency power supply line according to the second aspect of the present invention, in particular, the proximity effect generated at a high frequency is particularly strongly generated by making the cross-sectional area of one conductive line located at the center smaller than the other conductive lines. An increase in the current resistance value of the conductive wire located at the center can be further reduced.

  In the high-frequency power supply line according to the third aspect of the present invention, the surface area of the conductive wire can be increased by providing a groove on the outer periphery of the conductive wire. The increase in current resistance value due to the skin effect can be reduced.

In the high frequency power supply line according to the fourth aspect of the present invention, in particular, by using a connecting member for connecting the conductive wires, the conductive wires can be easily connected to each other, and the number of processing steps can be reduced.

In the high-frequency power supply line according to the fifth aspect of the present invention, in particular, by providing a slit in the connecting member that connects the conductive wires, the connecting member is deformed so that the diameter of the connecting member is reduced. In the press-fitted state, the contact pressure at the connection portion between the connection member and the conductive wire can be stabilized.

  1 to 3 show a high-frequency power supply line according to the first embodiment of the present invention. As shown in FIG. 1, in the high-frequency power supply line A formed integrally with a plurality of hollow conductive wires 1 having a hollow portion 6 therein and an insulator 2, one hollow conductive wire located at the center Means for arranging another hollow conductive wire 1b at an equal angle around 1a. This means is realized by positioning the plurality of hollow conductive wires 1 according to the shape of the insulator 2. Moreover, one hollow conductive wire 1a located in the center has a smaller cross-sectional thickness than the other hollow conductive wire 1b arranged around.

  Hereinafter, the high-frequency power supply line of this embodiment will be described in more detail. As shown in FIG. 2, the insulator 2 has a hole 2a having the same shape as the outer shape of the hollow conductive wire 1a covered with the outer coating 4 at the center position, and the outer periphery is equiangular with respect to the center. A plurality of positioning grooves 2b into which the hollow conductive wires 1b are fitted are formed at a pitch.

  Next, as shown in FIG. 3, the hollow conductive wire 1 a covered with the outer coating 4 is arranged and held in the hole 2 a at the center position of the insulator 2. Furthermore, by inserting the hollow conductive wire 1b covered with the outer coating 4 into a plurality of positioning grooves 2b formed on the outer periphery of the insulator 2, the hollow conductive wire 1a is arranged at the center so that another hollow conductive wire is provided. 1b is arranged at an equal angle around the hollow conductive wire 1a.

Then, as shown in FIG. 1, cover the outside of those together is arranged hollow conductive line 1b is a hollow conductive lines 1a are arranged hold the positioning groove 2 b of the insulator 2 at the center of the insulator 2 By forming the insulating layer 3 in this manner, the hollow conductive wire 1b is reliably held without being detached from the insulator 2, and the insulation between the hollow conductive wire 1b and the outside can be maintained.

  Thus, the hollow conductive wire 1 of the high-frequency feed line A of the present invention can be arranged at an equal angle with respect to the center.

  Moreover, the cross-sectional thickness of the hollow conductive wire 1a is formed thinner than other hollow conductive wires 1b disposed around. Here, the inner peripheral surface of the hollow at the center of the hollow conductive wire 1 functions as a skin portion for flowing a high-frequency current by the skin effect, and the skin depth δ through which the high-frequency current flows on the inner peripheral surface It is equal to the skin depth δ flowing on the outer peripheral surface of the line 1. Therefore, when the outer diameter of the hollow conductive wire 1 is r1, the inner diameter is r2, and the skin depth through which the high-frequency current flows is δ, it is desirable that r1 ≧ r2 + 2δ. In particular, the skin depth δ of the hollow conductive wire 1a located in the center is larger than the other hollow conductive wires 1b because the plurality of hollow conductive wires 1b are arranged around the skin depth δ. Therefore, it is necessary to reduce the outer diameter r1 or increase the inner diameter r2. Therefore, the current resistance value can be lowered by making the cross-sectional thickness of the hollow conductive wire 1a thinner than the other hollow conductive wires 1b.

  The manufacturing method for manufacturing the hollow conductive wire 1 is appropriate. The hollow conductive wire 1 having a predetermined size may be formed by an extrusion method or the like, or a conductive wire having a diameter larger than the predetermined size may be drawn. Can be manufactured by reducing the diameter to a predetermined size.

  Therefore, by arranging one hollow conductive wire 1a located at the center and another hollow conductive wire 1b at an equal angle around the plurality of hollow conductive wires 1, the plurality of hollow conductive wires 1 are evenly arranged with respect to the axial center. Therefore, when a high-frequency current is passed, the current density distribution becomes uniform, the skin effect can be effectively reduced, and the current resistance value can be lowered.

  Further, by making the cross-sectional thickness of one hollow conductive wire 1a located at the center thinner than that of the other hollow conductive wire 1b, the current of the hollow conductive wire 1a located at the center where the proximity effect generated at a high frequency is particularly strong is generated. The increase in resistance value can be further reduced.

  In the above, the high-frequency power supply line A configured by the hollow conductive wire 1 having the hollow portion 6 has been described, but the same can be achieved even when configured by a solid conductive wire having no hollow portion 6.

  FIG. 4 shows a high-frequency power supply line according to the second embodiment of the present invention. Here, only matters different from those in the first embodiment will be described, and other matters (configuration, operational effects, and the like) are the same as those in the first embodiment, and thus description thereof will be omitted. As shown in FIG. 4, the high-frequency power supply line A can increase the surface area of the hollow conductive wire 1 by providing a plurality of grooves 5 extending in the longitudinal direction on the outer peripheral surface of the hollow conductive wire 1. . Here, it is desirable that the grooves 5 are arranged on the outer periphery of the hollow conductive wire 1 at an equiangular pitch. Because the skin effect can be effectively reduced by making the current density distribution uniform, it is necessary to make the shape and arrangement of the hollow conductive wire 1 constituting the high-frequency feed line A uniform with respect to the center. It is.

  Therefore, since the surface area of the hollow conductive wire 1 can be increased by providing the groove 5 on the outer periphery of the hollow conductive wire 1, the current resistance value increases due to the skin effect when a high-frequency current is passed through the hollow conductive wire 1. Can be reduced.

  In the above, the high-frequency power supply line A configured by the hollow conductive wire 1 having the hollow portion 6 has been described, but the same can be achieved even when configured by a solid conductive wire having no hollow portion 6.

  The first and second embodiments of the present invention can be configured as follows. As shown in FIG. 5, the high-frequency power supply line A extends over both the hollow conductive wires 1 to the hollow portion 6 of the butt joint portion of the hollow conductive wire 1 butt-joined in the longitudinal direction and The hollow conductive wire 1 is connected via a connecting member 7 that is fitted so as to be pressed against the inner surface, and slits 9 that extend in the longitudinal direction are provided at both ends of the connecting member 7.

  FIG. 5 is a cross-sectional view taken along the longitudinal direction of one of the joints of the plurality of hollow conductive wires 1 when two high-frequency power supply lines A are joined. Both hollow conductive wires 1 are connected by fitting a connecting member 7 made of a conductor so as to straddle the hollow portions 6 of both hollow conductive wires 1 and press contact with the inner surface of the hollow portion 6. Here, since the connecting member 7 is joined by being press-fitted into the hollow portion 6 of the hollow conductive wire 1, the tolerance of the eyelash dimension is appropriately set for the inner diameter r2 of the hollow conductive wire 1 and the outer diameter R1 of the connecting member 7. There is a need to.

  In addition, the contact holding force can be improved by knurling the outer peripheral surfaces 7 a of both ends of the connecting member 7 that contacts the inner surface of the hollow portion 6 of the hollow conductive wire 1.

  Here, although the current resistance value of the connection member 7 increases due to the skin effect due to the high-frequency current flowing in the connection member 7, it can be reduced by making the central portion of the connection member 7 hollow like the hollow conductive wire 1. .

  Further, as shown in FIG. 5, when the connecting member 7 is press-fitted into the hollow portion 6 of the hollow conductive wire 1 by providing slits 9 extending in the longitudinal direction at both ends of the connecting member 7, the connecting member 7 It is easy to press-fit by deforming so that the diameters of both end portions thereof are reduced. Further, in a state where the connecting member 7 is press-fitted, elasticity is generated at both end portions of the connecting member 7, and the contact pressure at the connecting portion can be stabilized.

  In addition, by providing the connection member outer coating 8 on the outer periphery of the connection member 7 other than both end portions in contact with the hollow conductive wire 1, insulation from the outside can be ensured.

  Therefore, by using the connection member 7 for connecting the hollow conductive wires 1 to each other, the hollow conductive wires 1 can be easily connected to each other, and the number of processing steps can be reduced. Moreover, the contact surface between the hollow conductive wire 1 and the connection member 7 extends over the entire circumference, and the contact holding force can be improved by knurling the contact surface of the connection member 7. Moreover, the current resistance value can be reduced by making the center of the connecting member 7 hollow.

  Furthermore, the hollow member 6 of the hollow conductive wire 1 of the connecting member 7 is deformed so that the diameters of both ends of the connecting member 7 are reduced by providing the slit 9 in the connecting member 7 that connects the hollow conductive wires 1 to each other. It becomes easy to press-fit into the connector, and in the press-fitted state, the contact pressure of the connecting portion between the connecting member 7 and the hollow conductive wire 1 can be stabilized.

It is sectional drawing perpendicular | vertical with respect to the longitudinal direction of the high frequency electric power feeding line which is 1st Embodiment of this invention. It is sectional drawing perpendicular | vertical with respect to the longitudinal direction of the insulator which positions the hollow conductive wire of the same high frequency feeder. It is sectional drawing perpendicular | vertical with respect to the longitudinal direction of the state with which the hollow conductive wire of the same electric power feeding line is arrange | positioned at the insulator. It is sectional drawing perpendicular | vertical with respect to the longitudinal direction of the high frequency electric power feeding line which is the 2nd Embodiment of this invention. It is sectional drawing along the longitudinal direction of the junction part which carried out the butt-joining in the hollow conductive wire of the high frequency electric power feeding line which is the 1st and 2nd embodiment of this invention. It is sectional drawing perpendicular | vertical with respect to the longitudinal direction of the high frequency electric power feeding line using the subdivided litz wire which is a prior art example. It is sectional drawing perpendicular | vertical with respect to the longitudinal direction of the hollow conductive wire of the high frequency electric power feeding line which is a prior art example. It is sectional drawing perpendicular | vertical with respect to the longitudinal direction of the high frequency electric power feeding line using the some hollow conductive wire which is a prior art example.

Explanation of symbols

A High-frequency power supply line 1 Hollow conductive line 1a One hollow conductive line 1b located in the center 1b A plurality of hollow conductive lines located around 2 Insulator 2 b Positioning groove 3 Insulating layer 4 Outer coating 5 Groove 6 Hollow part 7 Connecting member 8 Connecting member outer cover 9 Slit

Claims (5)

A high-frequency power supply line formed by integrally forming a plurality of conductive lines including one conductive line and another conductive line arranged around the one conductive line and an insulator, have a means for placing at equiangular the other conductive wire around the first conductive line positioned, said means the one conductive line and the shape of the hole is formed in the center position, and on its outer circumference It is constituted by the insulator formed with a plurality of positioning grooves into which the other conductive wires are fitted at an equiangular pitch, and the plurality of conductive wires each have one hollow portion coaxial with the conductive wire. High frequency power supply line. High-frequency feed line of claim 1 wherein said one of conductive lines, wherein the cross-sectional thickness than the other conductive line disposed around small in the center. High-frequency feed line of claim 1, wherein the extended grooves in a longitudinal direction, characterized in that it is more circumferentially on the outer peripheral surface of the conductive wire. The conductive wire is connected via a connecting member that is fitted to the hollow portion of the butt-joined portion of the conductive wire butt-joined in the longitudinal direction so as to straddle both conductive wires and press-contact with the inner surfaces of the two conductive wires. The high-frequency power supply line according to any one of claims 1 to 3, wherein the high-frequency power supply line is provided. The high-frequency feed line according to claim 4, wherein slits extending in the longitudinal direction are provided at both ends of the connection member.

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