JP3605711B2 - Manufacturing method of high frequency shielded cable - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a high-frequency shielded cable, and more particularly, to a method for manufacturing a high-frequency shielded cable improved so that high-frequency characteristics can be improved.
[0002]
[Prior art]
A high-frequency shielded cable used for wiring of electronic equipment and communication equipment includes an inner conductor, a dielectric material layer formed on the outer periphery of the inner conductor, and an outer conductor formed on the outer periphery of the dielectric material layer. It is basically configured.
As the types of the outer conductor, there are a braid in which a plurality of conductive strips are braided, a metal-attached braid in which a metal is adhered to the braid, and a metal pipe.
[0003]
[Problems to be solved by the invention]
Among the above high-frequency shielded cables, the high-frequency shielded cable using a braid as an outer conductor and the high-frequency shielded cable using a metal-attached braid have a problem that high-frequency characteristics as designed cannot be obtained.
Therefore, an object of the present invention is to provide a method for manufacturing a high-frequency shielded cable using a braided outer conductor and an improved high-frequency shielded cable using a metal-adhered braid so that the high-frequency characteristics of the cable can be improved. It is in.
[0004]
[Means for Solving the Problems]
In a first aspect, the present invention provides an internal conductor, a dielectric material layer formed on an outer periphery of the internal conductor, and an outer conductor formed on an outer periphery of the dielectric material layer, wherein the outer conductor has a plurality of outer conductors. A method for manufacturing a high-frequency shielded cable, which is a braided body obtained by knitting the conductive band or a metal-adhered braid obtained by attaching a metal to the braid, wherein a plurality of conductive bands are provided on an outer periphery of the dielectric material layer. When forming a braided body by braiding the conductive band, a tension (back tension) of the conductive band is set to 0.50 N to 1.96 N and a die that does not press or reduce the diameter in the center direction is used. Provided is a method for manufacturing a cable.
The inventors of the present invention have conducted intensive studies and found that high-frequency shielded cables using a braided outer conductor and high-frequency shielded cables using a metal-attached braided cable cannot provide high-frequency characteristics as designed because of dielectric materials. It was found that the conductive band of the braid was cut into the layer, and the shape and dimensions of the outer conductor were not as designed. Further, it was found that in the high-frequency shielded cable using the metal-attached braid for the outer conductor, the metal was not sufficiently adhered to the braid.
Therefore, conventionally, the tension of the conductive band was set to 4N to 6N in order to prevent the conductive band from jumping and to improve the appearance of the braided body. In the method, the tension of the conductive strip was set to 0.50N to 1.96N. As a result, the braid was loosened and the appearance of the braided body was slightly deteriorated, but the conductive band of the braided body was prevented from biting into the dielectric material layer, and the high-frequency characteristics could be improved. Further, when the cable with the braid was passed through the molten metal bath, the molten metal easily permeated into the braid, the metal was sufficiently adhered to the braid, and high-frequency characteristics could be improved.
If the tension of the conductive band is smaller than 0.50 N, the conductive band cannot be knitted. Further, when the tension of the conductive strip is larger than 1.96 N, the conductive strip of the braided body may bite into the dielectric material layer.
[0005]
Furthermore, in order to improve the appearance of the braided body, a die that presses or reduces the diameter in the center direction has been used. However, this causes the conductive band of the braided body to bite into the dielectric material layer. Therefore, in the manufacturing method of the high-frequency shielded cables of the present invention, it was decided to use a die which is not pressurized or reduced in diameter toward the center. This prevents the conductive band of the braid from penetrating into the dielectric material layer, thereby improving high-frequency characteristics.
[0006]
In a second aspect , the present invention provides an internal conductor, a dielectric material layer formed on an outer periphery of the internal conductor, and an external conductor formed on an outer periphery of the dielectric material layer, wherein the external conductor has a plurality of conductors. A method for producing a high-frequency shielded cable which is a metal-attached braid in which a metal is adhered to a braid in which the conductive band is woven, comprising a plurality of conductive bands braided on the outer periphery of the dielectric material layer. After the body is formed into a cable with a braided body, when the cable with the braided body is passed through a molten metal tank to attach metal to the braided body, the feeding tension (back tension) of the cable with the braided body is 3N or less. To provide a method of manufacturing a high-frequency shielded cable.
The inventors of the present invention have conducted intensive studies and found that a high-frequency shielded cable using a metal-attached braid for the outer conductor does not provide high-frequency characteristics as designed because metal is not sufficiently adhered to the braid. It turned out to be.
Therefore, conventionally, in order to prevent the cable with a braided body from loosening or bouncing, the extension tension of the cable with a braided body passed through the molten metal tank was set to 9N to 10N. However, the high-frequency shielded cable of the present invention according to the second aspect described above. In the method of (1), the feeding tension of the braided cable was set to 3N or less. Thereby, the amplitude of expansion and contraction of the braided body at the time of unreeling increased, the molten metal easily penetrated into the braided body, the metal sufficiently adhered to the braided body, and high-frequency characteristics could be improved.
If the tension of the cable with the braid is set to be greater than 3N, the high-frequency characteristics may not be sufficiently improved.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited to this.
[0008]
FIG. 1 is a schematic view of a cable manufacturing apparatus 100 with a braid for implementing the method for manufacturing a high-frequency shielded cable according to the present invention.
The cable 1 with a dielectric material layer having an outer diameter of 2.85 mm is supplied from the reel 10, passes through the insertion hole at the center of the rotating disk 11, and enters the die 14.
[0009]
As shown in FIG. 2, the cable 1 with a dielectric material layer includes an inner conductor 4 made of copper and a dielectric material layer 5 made of polytetrafluoroethylene covering the outer periphery thereof.
[0010]
Returning to FIG. 1, a plurality of conductive strip feeding devices 12 are circumferentially arranged on the rotating disk 11, and a plurality of conductive strips made of copper are provided from the conductive strip feeding devices 12. The body 13 is paid out with a tension (back tension) of 0.50N to 1.96N.
[0011]
FIG. 3A shows a front view of the conductive band feeding device 12, and FIG. 3B shows a cross-sectional side view of the conductive band feeding device 12.
The conductive strip 13 is supplied from a reel 30 and is fed out through a pressing roller 31, a tension roller 32, and a pressing roller 33.
The reel 30 is braked by a brake mechanism 39 so as not to rotate unnecessarily.
The tension roller 32 is supported by a tension arm 35, and the tension arm 35 is given a force by a spring 37 to rotate about a tension shaft 36. The tension of the conductive strip 13 can be adjusted by adjusting the force of the spring 37 with the spring adjusting screw 38 while checking with the push-pull gauge 40.
[0012]
As shown in FIG. 4, the plurality of conductive strips 13 are woven together by the rotation of the rotating disk 11 on the outer periphery of the cable 1 with the dielectric material layer entering the die 14, and the braided body (FIG. 5) 6) is formed. And the cable 1 with a dielectric material layer becomes the cable 2 with a braided body.
The outer diameter of the cable 2 with a braid is 3.5 mm, and the hole diameter of the die hole 14a is 4.0 mm. In this manner, a margin of 14% to 30% with respect to the outer diameter of the braided cable 2 is provided in the die hole so that the braided cable 2 is not pressed or reduced in the center direction by the die 14. It is preferable to have a hole diameter of 14a.
[0013]
As shown in FIG. 5, the cable 2 with a braid includes an inner conductor 4 made of copper, a dielectric material layer 5 covering the outer periphery, and a braid 6 covering the outer periphery. Although the cable 2 with the braid can be used as a high-frequency shielded cable as it is, a metal is attached to the braid 6 to improve high-frequency characteristics.
[0014]
FIG. 6 is a schematic diagram of a high-frequency shielded cable manufacturing apparatus 200 that implements the high-frequency shielded cable manufacturing method of the present invention.
The cable 2 with a braided body having an outer diameter of 3.5 mm is supplied from a reel 20, enters a molten metal tank 21 in which molten tin or solder is stored, passes through a pulley 25 in the molten metal tank 21, and Get out of the tank 21. Then, the high-frequency shielded cable 3 passes through a drawing die 22 having a hole diameter of 3.5 mm, passes through a cooling device 23, and is wound around a reel 24.
[0015]
A torque adjusting mechanism (perm torque) 28 is attached to the reel 20. The unwinding tension of the braided cable 2 is adjusted by the torque adjusting mechanism 28 so as to be 0N to 3N.
[0016]
The molten tin or solder enters into the gaps between the braids 6 of the cable 2 with a braid entered into the molten metal bath 21. The braid 6 expands and contracts before and after passing through the pulley 25, and the molten tin or solder permeates into the braid 6. Then, by passing through the drawing die 22, extra tin or solder attached is drawn out, and the outer diameter is made uniform. Further, the metal is solidified by the cooling device 23.
[0017]
As shown in FIG. 7, the high-frequency shielded cable 3 includes an inner conductor 4 made of copper, a dielectric material layer 5 made of polytetrafluoroethylene covering the outer periphery thereof, and a braided metal body 7 covering the outer periphery thereof.
[0018]
In the high-frequency shielded cable 3 manufactured as described above, the tension at the time of feeding out the conductive band 13 from the conductive band feeding device 12 was set to 0.50 N to 1.96 N. Of the conductive band 13 is prevented from digging into the dielectric material layer 5. Also, since the braided cable 2 is not pressed or reduced in the center direction by the die 14, the conductive band 13 of the braid 6 is also prevented from biting into the dielectric material layer 5 in this regard. Have been. Further, the tension of the cable 2 with a braided body is loosened from 0N to 3N and the molten metal is passed through the molten metal tank 21, so that the molten metal permeates the braided body 6 and adheres sufficiently. Therefore, high frequency characteristics can be improved.
In addition, the cable 2 with a braid can be used as it is as a high frequency shielding cable. Even in this case, the conductive band 13 of the braided body 6 is prevented from biting into the dielectric material layer 5, so that high-frequency characteristics can be improved.
[0019]
FIG. 8 shows the voltage standing wave ratio characteristics of the high-frequency shielded cable 3 of the embodiment in which the tension of the conductive band 13 is 1.67 N and the extension tension of the cable 2 with the braid is 0 (free).
For comparison, FIG. 9 shows the voltage standing wave ratio characteristics of the high-frequency shielded cable 3 when the tension of the conductive band 13 is 4.7 N and the extension tension of the cable 2 with the braid is 9.8 N. .
As can be seen from a comparison between the two, the voltage standing wave ratio is always 1.1 or less in the high-frequency shielded cable 3 of the embodiment of the present invention, but the voltage standing wave ratio is 1.0 GHz to 15 GHz in the comparative example. More than one.
[0020]
FIG. 10 shows the return loss characteristics of the high-frequency shielded cable 3 of the embodiment in which the tension of the conductive band 13 is 1.67 N and the extension tension of the cable 2 with the braid is 0 (free).
For comparison, FIG. 11 shows the return loss characteristics of the high-frequency shielded cable 3 when the tension of the conductive band 13 is set to 4.7 N and the extension tension of the cable 2 with the braid is set to 9.8 N.
As can be seen from a comparison between the two, the return loss is always -25 dB or less in the high-frequency shielded cable 3 according to the embodiment of the present invention, but the return loss exceeds -25 dB at 10 GHz to 15 GHz in the comparative example.
[0021]
FIG. 12 shows the voltage standing wave ratio characteristics of the high-frequency shielded cable 3 when the tension of the conductive band 13 is changed and the feeding tension of the braided cable 2 is set to 0 (free).
It can be seen that in order to make the voltage standing wave ratio 1.1 or less, the tension of the conductive band 13 should be 1.96 N or less.
[0022]
【The invention's effect】
According to the method for manufacturing a high-frequency shielded cable of the present invention, the following effects can be obtained.
(1) When knitting a plurality of conductive strips into a cable with a dielectric material layer to form a braided body, the feeding tension (back tension) of the conductive strips is 0.50 N to 1.1. By setting it to 96N, it is possible to prevent the conductive strip from biting into the dielectric material layer. Further, the molten metal easily permeates the braid. Therefore, a high-frequency shielded cable having excellent high-frequency characteristics can be obtained.
(2) When forming a cable with a braided body, by giving a margin to the outer diameter of the cable in the hole diameter of the die so as not to press or reduce the diameter, it is possible to prevent the conductive band from biting into the dielectric material layer. Further, the molten metal easily permeates the braid. Therefore, a high-frequency shielded cable having excellent high-frequency characteristics can be obtained.
(3) When the cable with the braid is passed through the molten metal tank to adhere the metal, the braid can be expanded and contracted by setting the feeding tension (back tension) of the cable with the braid to 3 N or less. The molten metal easily penetrates into the inside. Further, it is possible to prevent the cable with the braid from contracting in the center direction. In this way, the metal penetrates into the braid, whereby the high-frequency shielding performance is enhanced, and a high-frequency shielding cable having excellent high-frequency characteristics is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view of an apparatus for manufacturing a cable with a braid for implementing a method for manufacturing a high-frequency shielded cable according to the present invention.
FIG. 2 is a sectional view of a cable with a dielectric material layer.
FIG. 3 is a front view and a cross-sectional side view of the conductive band feeding device.
FIG. 4 is a schematic view showing a state in which a braided cable passes through a die. (The dice are sectional views.)
FIG. 5 is a cross-sectional view of a cable with a braid.
FIG. 6 is a schematic view of an apparatus for manufacturing a high-frequency shielded cable for performing the method for manufacturing a high-frequency shielded cable of the present invention.
FIG. 7 is a cross-sectional view of a high-frequency shielded cable.
FIG. 8 is a characteristic diagram of a voltage standing wave ratio of the high-frequency shielded cable of the example.
FIG. 9 is a characteristic diagram of a voltage standing wave ratio of a high-frequency shielded cable of a comparative example.
FIG. 10 is a characteristic diagram of the return loss of the high-frequency shielded cable according to the embodiment.
FIG. 11 is a characteristic diagram of the return loss of the high-frequency shielded cable of the comparative example.
FIG. 12 is a characteristic diagram of the tension of the conductive band and the voltage standing wave ratio.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 cable with dielectric material layer 2 cable with braided body 3 high-frequency shielded cable 4 inner conductor 5 dielectric material layer 6 braided body 7 braided body with metal 12 conductive band feeding device 14 dice 21 molten metal tank 28 torque adjustment mechanism 100 Braided cable manufacturing device 200 High-frequency shielded cable manufacturing device

Claims (2)

A braided body comprising: an inner conductor; a dielectric material layer formed on the outer periphery of the inner conductor; and an outer conductor formed on the outer periphery of the dielectric material layer, wherein the outer conductor is woven with a plurality of conductive bands. Or a method for manufacturing a high-frequency shielded cable which is a metal-attached braid in which a metal is adhered to the braid, wherein a braid is formed by knitting a plurality of conductive bands around the dielectric material layer, A method for manufacturing a high-frequency shielded cable, wherein a tension (back tension) of a conductive strip is set to 0.50 N to 1.96 N and a die that does not press or reduce diameter in a center direction is used . A braided body comprising: an inner conductor; a dielectric material layer formed on the outer periphery of the inner conductor; and an outer conductor formed on the outer periphery of the dielectric material layer, wherein the outer conductor is woven with a plurality of conductive bands. A method for producing a high-frequency shielded cable, which is a metal-attached braid having metal adhered thereto, wherein a plurality of conductive strips are knitted around the dielectric material layer to form a braided body to obtain a cable with a braided body. Thereafter, when passing the braided cable through the molten metal tank to attach metal to the braided body, the feeding tension (back tension) of the braided cable is set to 3N or less. Manufacturing method .

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