JPH09259651A - Shock resistant cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily accurately perform wire stripping, by cutting a shock absorbing layer between two insulated wires, without flawing a conductor by a small cut part. SOLUTION: Two insulated wires 10 are arranged by interposing a spacer 20 in a space therebetween, and in this periphery, a shock absorbing layer 30 is formed, and this periphery is coated with a PVC sheath 40. The shock absorbing layer 30 is broken between the two insulated wires 10. In the case of stripping this shock resistant cable, a notch of depth reaching the spacer 20 from a cutter 60 is generated from the upper/lower in a plane central part in the end part. Next, a coated layer 50 in a part generating the notch is separated right/left direction, the spacer 20 is separated, and the insulated wire 10 is exposed. Thereafter, the separated coated layer 50 and the spacer 20 are cut off by the cutter, an insulating layer 11 of the insulated wire 10 is removed by a stripping tool, and a conductor 12 is exposed. In this way, by a small notch part, without flawing the conductor, stripping can be easily accurately performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact resistant cable which can be easily peeled off (removal of an insulating layer at a cable end).

[0002]

2. Description of the Related Art An indoor wiring cable used for wiring in a condominium or under the floor of a single-family house has a conductor 12 and a PVC (polyvinyl chloride) insulating layer 11 as shown in FIG.
A flat cable in which a plurality of insulated electric wires 10 which are insulation-coated with are arranged in parallel and covered with a PVC sheath 40, which is usually called a VVF cable. Since this VVF cable is inferior in impact resistance, it is laid in a protective tube. However, since the work of pulling the VVF cable into the protective tube is troublesome, a shock resistant cable (reinforced VVF cable) that does not require the protective tube is used.
(Also called cable) was developed. As shown in FIG. 7, this impact resistant cable has a shock absorbing layer 30 made of urethane resin or the like formed around each of a plurality of insulated electric wires 10 arranged in parallel at intervals. The circumference of is surrounded by a PVC sheath 40.

[0003]

By the way, when the VVF cable shown in FIG. 6 is electrically connected, the stripping tool is used to remove the VVF cable at a predetermined position near the end of the coating layer in the longitudinal direction of the cable. This is done by making a cut at a right angle, moving the peeling tool to the end of the cable, and pulling out the coating layer at the end. However, in the case of the impact resistant cable shown in FIG. 7, a thermoplastic elastomer is used for the impact absorbing layer, and this one has excellent elasticity and permanent set characteristics and is tough at the same time. Went as follows. That is, in this work, as shown in FIGS. 8A and 8B, the cutter 60 is used to make notches at four positions above and below where the insulated electric wire 10 is located at the end of the impact resistant cable (FIG. 8A).
The coating layer 50 composed of the C sheath 40 and the shock absorbing layer 30 is divided into three (FIG. 8B), the divided coating layers 50 are cut and removed to expose the insulated electric wire 10, and then the insulating layer of the insulated electric wire 10 is exposed. 11 is removed with a peeling tool. Among them, the cutting work with a cutter is a laborious and time-consuming work that may damage the conductor 12 because it makes four cuts toward the insulated electric wire 10 and the mouth peeling work is difficult. there were.

From the above, as shown in FIG.
Interposition of a material with good impact resistance between multiple insulated wires 10
70 is provided, a protective layer 80 made of a material having good elastic force and tearability is provided between the insulated wire 10 and the insulating layer 11, and
A shock-resistant cable in which 80 and PVC sheath 40 are in close contact with each other and has good tear resistance has been proposed (Japanese Patent Publication No. 56-42089). This product has an effect that when the cable is bent, the protective layer 80 is easily cracked along the circumference when the cable is bent, and the lip can be easily peeled off. However, this cable is inferior in impact resistance (elasticity, permanent set characteristics, and toughness) because the protective layer has good tearability, so that there is a problem that the application is restricted. An object of the present invention is to provide an impact resistant cable which has a sufficient impact resistance function and which can be easily removed without fear of damaging the conductor of the coating layer.

[0005]

According to the first aspect of the present invention,
In a shock resistant cable in which a shock absorbing layer is provided around a plurality of insulated electric wires arranged in parallel at intervals, and a plastic sheath is formed on the outside thereof, the shock absorbing layer is interrupted between the insulated electric wires. It is an impact resistant cable characterized in that a spacer continuous in the longitudinal direction is arranged between a plurality of insulated wires.

In this impact resistant cable, a spacer is arranged between the insulated wires so that the shock absorbing layer is discontinued between the insulated wires. That is, the spacers are arranged so that there is a portion where the shock absorbing layer does not intervene between the adjacent insulated wires. Therefore, the coating layer can be peeled off by making at least one cut in the coating layer. Furthermore, since the notch is made toward the spacer, there is no fear of damaging the conductor. Any material such as rubber, plastic, or paper can be applied to the spacer. The cross-sectional size of the spacer may be small as long as the shock absorbing layer is discontinuous between the insulated wires. If the spacer is made of a material that adheres to the insulated wire or the shock absorbing layer, the surface should be non-adhesive treated before use.

The material of the shock absorbing layer is preferably a thermoplastic elastomer excellent in impact resistance (elasticity, permanent set characteristics, toughness). Specifically, it is urethane resin or the like. It also includes a mixture of urethane resin and vinyl chloride resin.

The invention according to claim 2 is characterized in that a notch serving as a guide of a cutter when a cut is made at a predetermined position of the shock absorbing layer is continuously formed in the longitudinal direction. It is an impact resistant cable.

In this impact resistant cable, the notch is formed at the cut position of the shock absorbing material, and if the notch position is confirmed on the end face of the cable and the cut is made by the cutter, the cut into the shock absorbing material is accurate. You can do it. With this invention,
The place where the notch is formed is, for example, the place where the blade edge of the cutter hits the spacer by moving the cutter along the notch. The notch may be formed in one place or two or more places.

[0010]

1 is a cross-sectional view showing a first embodiment of an impact resistant cable according to the present invention. 2 insulated wires
10 are arranged with a spacer (cardboard) 20 sandwiched between them, a shock absorbing layer (urethane resin layer) 30 is formed around the spacer, and the periphery thereof is covered with a PVC sheath 40. The shock absorbing layer 30 is discontinuous between the two insulated wires 10.

2A and 2B show an example of a method of stripping the impact resistant cable shown in FIG. Make a notch from the top and bottom to reach the spacer 20 with the cutter 60 in the center of the flat surface of the impact resistant cable (Fig. 2A). Next, the coating layer (PVC sheath 40 and shock absorbing layer 30) of the cut portion 50
To the left and right, and the spacer 20 to separate to expose the insulated wire 10 (Fig. 2B). Coating layer separated after this
50 and the spacer 20 are cut and removed by a cutter, and the insulating layer 11 of the insulated wire 10 is removed by a peeling tool (not shown) to expose the conductor 12.

Another example of the method of stripping the impact resistant cable shown in FIG. 1 is shown in FIGS. In this example, the notch is made only in one place. That is, a notch having a depth reaching the spacer 20 is made from above by the cutter 60 at the center of the plane of the end of the impact resistant cable (FIG. 3A). Next, the insulating layer 10 is exposed by pulling down the coating layer 50 and the spacer 20 at the notched portion (FIG. 3B). After that, the coating layer 50 and the spacer 20 portion that have been pulled down are cut and removed, and then the insulating layer 11 of the insulated wire 10 is removed by a peeling tool (not shown) to form a conductor.
Expose twelve.

FIG. 4 shows a second embodiment of the impact resistant cable of the present invention.
It is a cross-sectional view showing an embodiment of. In this impact resistant cable, concave notches 31 are continuously formed in the longitudinal direction at the top and bottom of the central portion of the plane of the impact absorbing layer 30 where the spacer 20 is located. In this example, the position of the notch 31 is confirmed on the end face of the impact resistant cable, and the cutter is moved along the concave notch 31 so that the notch is accurately made at a predetermined position of the PVC sheath 40 and the impact absorbing layer 30. You can

FIG. 5 shows a third embodiment of the impact resistant cable of the present invention.
It is a cross-sectional view showing an embodiment of. In this impact resistant cable, concave and convex notches 32 are continuously formed in the longitudinal direction above and below the center of the plane where the spacer 20 of the impact absorbing layer 30 is located. In this example, when the cutter is brought into contact with the inclined surface 33 of the concave-convex notch 32 from the concave portion to the convex side and moved, the orientation of the cutter is supported uniformly and the position of the cutting edge of the cutter can be stabilized.

The impact resistant cable of the present invention can be manufactured by a conventional extrusion method. That is, a core material is obtained by sandwiching a spacer between two insulated wires, and a shock absorbing layer is extrusion-coated around the core material, and a PVC sheath is extrusion-encapsulated on the impact absorption layer. To form a notch in the shock absorbing layer, a method using an extrusion die having a convex portion or a concave portion on the inner surface, or P
Before encapsulating the VC sheath, a method of pressing a cutting tool or a sprocket-shaped rotary blade against a predetermined portion of the shock absorbing layer is applied. When using an extrusion die or pressing a cutting tool, the notches are formed continuously in a linear shape. When a sprocket-shaped rotary blade is pressed, the notches are continuous in a dot shape.

The impact resistant cable of the present invention shown in FIGS. 1, 4 and 5 was wired indoors without using a protective tube. However, it has the same long-term trouble as the conventional impact resistant cable wired in the protective tube. Could be used without.

Although the impact resistant cable in which two vinyl insulated wires are arranged has been described above, the present invention is applicable even when the insulated wire is an insulated wire coated with other plastic material such as polyethylene other than the vinyl insulated wire. The same effect can be obtained even when the number of parallel insulated wires is three or more. Further, the present invention has the same effect when applied to a cable whose impact absorbing layer is made of a material having excellent tearability.

[0018]

As described above, in the impact resistant cable of the present invention, the spacers are arranged between the insulated wires and the impact absorption layer is discontinuous between the insulated wires. Therefore, the mouth can be easily peeled off with a small number of cuts. Also, by making a cut toward the spacer 20, there is no risk of damaging the conductor. Further, by forming a notch in the shock absorbing layer, it is possible to cut a predetermined position with high accuracy. Therefore, the workability of laying the impact resistant cable is significantly improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an impact resistant cable of the present invention.

FIG. 2 is an explanatory diagram showing an example of a method of peeling the impact resistant cable shown in FIG.

FIG. 3 is an explanatory view showing another example of the method of peeling the impact resistant cable shown in FIG.

FIG. 4 is a cross-sectional view showing a second embodiment of the impact resistant cable of the present invention.

FIG. 5 is a cross-sectional view showing a third embodiment of the impact resistant cable of the present invention.

FIG. 6 is a cross-sectional view of a conventional indoor wiring VVF cable.

FIG. 7 is a cross-sectional view of a conventional impact resistant cable.

FIG. 8 is an explanatory diagram of a method of peeling the conventional impact resistant cable shown in FIG.

FIG. 9 is a cross-sectional view of a conventional impact resistant cable.

[Explanation of symbols]

 10 …… Insulated wire 11 …… Insulated wire insulation layer 12 …… Conductor 20 …… Spacer 30 …… Impact absorption layer 31 …… Concave notch 32 …… Concave notch 33 …… Sloping surface from concave to convex 40 …… PVC sheath 50 …… Coating layer 60 …… Cutter 70 …… Interposition 80 …… Protective layer

Claims (2)

[Claims] 1. A shock-resistant cable in which a shock-absorbing layer is provided around a plurality of insulated wires that are arranged in parallel at a distance, and a plastic sheath is formed on the outside thereof. A shock-resistant cable, characterized in that a spacer continuous in the longitudinal direction is arranged between the plurality of insulated wires so as to be interrupted. 2. The impact resistance according to claim 1 or 2, wherein a notch serving as a guide for the cutter when making a cut in a predetermined portion of the impact absorbing layer is continuously formed in the longitudinal direction. Sex cable.