JPH02201817A - Shielded cable - Google Patents

Abstract

PURPOSE:To improve a shielding effect, make bending good, and prevent occurrence of environmental pollution and accidents at the time of processing terminals by forming a shielding layer of copper foil thread consisting of resin fibers covered with copper foil around a cable core. CONSTITUTION:A shielding layer 4 of copper foil thread 3 consisting of resin fibers 1 covered with copper foil 2 is formed around a cable core A. A sufficient shielding effect can thus be achieved. A larger elongation can be obtained than a conventional spun yarn of stainless fibers, the flexibility is good, and it is durable to excessive external force. In addition, the copper foil 2 of the copper foil thread 3 has a larger rolling property than stainless, and powders are less likely to be scattered at the time of cutting the copper foil thread 3, thereby occurrence of environmental pollution or accidents can be prevented at the time of processing the terminals of an obtained cable.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a cable used for moving parts of medical instruments, robots, etc., and the cable is required to be flexible, and moreover, the cable is required to have flexibility over its entire length. This relates to shielded cables that require collective shielding.

(Prior Art) Examples of conventional shielded cables include medical device probe cables. This cable is a signal transmission cable for imaging the inside of the human body using an ultrasonic probe, and due to the nature of the atmosphere in which it is used, flexibility (flexibility) and shielding performance (noise resistance) are required. As shown in Figure 3, a shielded cable that has excellent both of these properties is generally used, in which a shield layer B made of braided stainless fiber spun yarn is formed around the outer periphery of a cable core A. There is.

(Problem to be solved by the invention) However, although the shielded cable using the above-mentioned stainless steel fiber spun yarn as the shield layer B has excellent flexibility, the conductivity of stainless steel itself is lower than that of copper, so the cable The shielding performance in the mounting environment was not satisfactory.

In addition, when processing the end of a cable, if the stainless steel fiber spun yarn is cut, the spun yarn becomes stainless steel and scatters, which not only causes pollution that is harmful to the human body, but also adheres to circuits, etc. There was a problem in that accidents such as short-circuits were likely to occur.

(Object of the Invention) The object of the present invention is to provide a shielded cable that can exhibit sufficient shielding performance in the cable mounting atmosphere, has excellent flexibility, and furthermore reduces the above-mentioned pollution and occurrence of accidents during terminal processing. It's about doing.

(Means for solving the gap) The shielded cable of the present invention has a cable core A made up of a collection of one or more signal lines as shown in FIG.
Copper foil thread 3 made by horizontally winding copper foil 2 around resin fiber L is placed around the outer periphery of
It is characterized in that a shield layer 4 as shown in FIG. 2 is formed.

(Function) In the shielded cable of the present invention, since the copper foil thread 3 using the copper foil 2 is used for the shield layer 4, the conductivity is as good as that of copper, and the cable is sufficiently shielded in the mounting atmosphere. sexuality is demonstrated.

In addition, the flexibility of the cable containing cable core A is
Although it is thought that this depends on the degree of restraint of the structure covering the cable core A, the shield layer 4 of the shielded cable of the present invention uses a copper foil thread 3 in which a copper foil 2 is wrapped around a resin fiber 1 such as Tetoron thread. Therefore, when stress such as bending, twisting, or tension is applied to the cable! ! 4. The wrapping of the foil 2 is easy to shift (it has more elongation than conventional stainless steel fiber spun yarns, resulting in a shielded cable with excellent flexibility, and the stresses such as torsion and tension are alleviated.

The above f! Since the copper foil 2 used in the four-foil thread 3 is softer than stainless steel, its powder is less likely to scatter during cutting.

(Embodiment) FIG. 1 shows an embodiment of the shielded cable of the present invention. In this figure, A is a cable core made up of a plurality of signal lines C, for example, coaxial lines are used for this as in the conventional signal IIC, and these are twisted together.

Reference numeral 6 in FIG. 1 is a pressing layer provided on the outer periphery of the cable core A, and Teflon tape or the like is used for this layer.

Reference numeral 7 shown in FIG. 1 is a drain line provided inside the shield layer 4, which improves terminal processability and
This is for grounding the shield layer 4, and a mild steel wire or the like is used for this. This drain line 7 may be optional depending on the case.

Reference numeral 4 shown in FIG. 1 is a shield layer, which is formed by horizontally winding (closely wound) the copper foil thread 3 shown in FIG. 2 with uneven composition.

As shown in FIG. 2, the copper foil thread 3 is made by horizontally (closely winding) the copper foil 2 on the outside of a plurality of bundled resin fibers l such as Tetoron threads. In this example, the f!
A copper foil thread 3 formed by wrapping four foils 2 was used. This copper foil thread 3 has been conventionally used in curled cords for telephones, and has sufficient flexibility.

In the shielded cable shown in Fig. 1, 96 signal wires C with a diameter of 0.6 mm are bundled to form a cable core A with a diameter of 8 mm, and the copper foil thread 3 with a diameter of 0.12 mm is braided at an angle of 60°.
The shield layer 4 is made by braiding at an appropriate pitch with a density of 80% or more. In addition to being braided, this copper foil thread 3 can be used as the shield layer 4 by, for example, being double horizontally wound or double horizontally wound.

(Effects of the Invention) In the shielded cable of the present invention, a copper foil thread 3 having an electrical conductivity close to that of copper is used for the shield layer 4, and the copper foil thread 3 has a resin fiber 1 wrapped around a copper foil 2. As a result, it has the following effects:

■ Sufficient shielding performance can be achieved in the environment where the cable is mounted.

■Compared to conventional stainless steel fiber spun yarns, it has more elongation and flexibility, and is also more durable as it can withstand excessive external forces.

■Since the copper foil 2 of the copper foil thread 3 has higher ductility than stainless steel, there is less scattering of powder when cutting the copper foil thread 3 (pollution and accidents are less likely to occur when processing the cable end) .

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an embodiment of the shielded cable of the present invention, Fig. 2 is a perspective view of the copper foil thread used in the shield layer of the same cable, and Fig. 3 is a cross-sectional view of a conventional shielded cable. It is a diagram. ■Resin fiber 2 is copper foil 3 is copper foil thread 4 is shield layer A is cable core

Claims (1)

[Claims] A shield layer 4 is formed on the outer periphery of a cable core A made up of a collection of one or more signal lines, using a copper foil thread 3 made by horizontally wrapping a copper foil 2 around a resin fiber 1. Shielded cable.