JPH0682724U - Flex resistant coaxial cable - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a coaxial cable that is flexible, has excellent flex resistance, and is lightweight. A coaxial cable composed of an inner conductor 1, an insulator 2, an outer conductor 3 and a sheath layer 4 includes at least a conductive resin layer formed by extrusion.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a coaxial cable for signal transmission, and particularly to a coaxial cable suitable for transmitting a signal to a frequently moving device such as a robot.

[0002]

[Prior art]

 Conventionally, a coaxial cable for signal transmission is provided with an insulating layer on an inner conductor, and a metal conductor wire is wound horizontally on the inner conductor, or an outer conductor is formed with a metal conductor braid, and the insulation conductor is further formed on it. It is known that a sheath layer is provided.

[0003]

[Problems to be solved by the device]

 If such a coaxial cable is used by connecting it to a frequently moving device such as a robot, the cable will break with the outer conductor and inner conductor at the beginning within a short time due to bending fatigue. Occurs. For this reason, studies have been conducted on the use of high-strength materials as conductors, but none have been obtained that are sufficiently satisfactory. Further, since the metal conductor is used, there is a problem that it becomes heavy.

An object of the present invention is to solve the problems of the conventional coaxial cable, and to provide a coaxial cable which is flexible, has excellent bending resistance, and is lightweight.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present inventors considered increasing the bendability of the outer conductor, which is considered to be the weakest in the constituent materials against bending, and conducted extensive studies, and as a result, completed the present invention. It was

That is, the present invention provides a coaxial cable composed of an inner conductor, an insulating layer, an outer conductor, and a sheath layer, wherein the outer conductor contains at least an extruded conductive resin, and the bending resistance is improved. It is a coaxial cable.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an example of the coaxial cable of the present invention, in which 1 is an inner conductor, 2 is an insulating layer, 3 is a conductive resin layer, and 4 is a sheath layer.

The conductive resin forming the conductive resin layer 3 is a fluorine resin such as FEP, PFA, or PTFE mixed with a conductive substance such as carbon, and has a volume resistivity of 10 ^0. It is preferably from 10 ⁻² Ω / cm. The conductive resin layer 3 is formed by extrusion on the insulating layer 2, and its thickness is preferably 0.05 mm or more.

FIG. 1 shows an example in which the conductive resin layer 3 is used alone, but the present invention is not limited to this, and the conductive resin layer 3 and the metal conductor braid, metal It may be used in combination with a conductor winding, a metal conductor wire, a metal foil, a metal foil laminating tape, or the like.

FIG. 2 shows an example in which the metal conductor braid 3a is provided on the conductive resin layer 3, and FIG. 3 shows the metal conductor braid 3a and the metal conductor laterals above and below the conductive resin layer 3, respectively. An example in which the winding 3b is provided, and FIG. 4 shows an example in which the conductive resin layer 3 and the metal conductor wire 3c are used in combination.

The combination and arrangement of the conductive resin layer 3 and the metal conductor braid 3a, the metal conductor horizontal winding 3b, the metal conductor wire 3c, etc. are not limited to the above examples, but may be different depending on the application. , Can be arbitrarily selected.

Now, a thickness of 0.3 mm made of tetrafluoroethylene-hexafluoropropylene copolymer (hereinafter abbreviated as FEP) is formed on an inner conductor formed by twisting 30 0.05 mm silver-plated annealed copper wires. Of the conductive tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (hereinafter, abbreviated as conductive PFA) having a thickness of 0.1 mm is extruded and formed on the insulating layer. A conductor composed of seven annealed copper wires is vertically attached to form an outer conductor, and a thickness of FEP of 0. A coaxial cable of the present invention was prepared by forming a 2 mm sheath layer.

On the other hand, for comparison, in the above coaxial cable, a silver-plated annealed copper wire having a diameter of 0.08 mm was horizontally wound instead of the conductive PFA layer to prepare a coaxial cable as an outer conductor.

The flex resistance of both coaxial cables was measured with reference to JIS C 3005. The former (the present invention) showed that the coaxial characteristics did not deteriorate even after being bent 500,000 times. The latter (conventional example) had a break in the outer conductor, and the coaxial cable of the present invention had significantly improved bending resistance. The weight was also reduced by about 15%.

[0015]

[Effect of device]

 INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain a coaxial cable that can be lightened in weight, is flexible, and has excellent flex resistance, and can be used as a coaxial cable that is used by connecting to frequently moving equipment such as a robot. Are suitable.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a bend-resistant coaxial cable of the present invention.

FIG. 2 is a perspective view showing another example of the bending-resistant coaxial cable of the present invention.

FIG. 3 is a perspective view showing still another example of the bending-resistant coaxial cable of the present invention.

FIG. 4 is a perspective view showing another example of the flex-resistant coaxial cable of the present invention.

[Explanation of symbols]

 1 Inner Conductor 2 Insulating Layer 3 Conductive Resin Layer 3a Metal Conductor Braid 3b Metal Conductor Horizontal Winding 3c Metal Conductor Wire 4 Sheath Layer

Claims (1)

[Scope of utility model registration request] 1. A bend-resistant coaxial cable comprising a coaxial cable comprising an inner conductor, an insulator, an outer conductor and a sheath layer, the outer conductor including at least a conductive resin layer formed by extrusion.