JPH08105584A - Coupling for cable protective pipe - Google Patents

Abstract

PURPOSE: To provide a coupling for cable protective pipe which does not concentrate a bending stress to a cable protective pipe near the connection, and can be used by connecting the cable protective pipe in the condition to exercise an excellent water stop performance without generating a breakage. CONSTITUTION: A pipe connection 11 to connect a cable protective pipe 3 to the end of a pipe coupling main body is provided, and an extension 2 which consists of a rubber elastic body is formed at the tip of an outer pipe 111 to form the pipe connection 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable protection pipe joint for connecting a cable protection pipe such as a spiral pipe.

[0002]

2. Description of the Related Art Conventionally, as a cable protection tube, for example, a spiral tube as shown in FIG. 5 has been used. This spiral tube a has a fitting portion c on one side edge, which is bifurcated and in which the retaining portions b, b are provided opposite to each other on the inner edge of the opening end, and slides on the other side edge into the fitting portion c. A strip-shaped synthetic resin profile e having a locking portion that is movably fitted and locked is spirally wound, and a fitting portion c and a locking portion d that are adjacent to each other in the wound state are fitted together. It is formed into a tubular shape.

Further, such a spiral tube a has a locking portion d.
Is slidable in the fitting portion c in the axial direction of the spiral tube a so that it can be expanded and contracted or bent.

Since the spiral pipe a has flexibility, it is mainly used in the bent portion of the pipe line.
6, the end portion of the spiral tube a is inserted into the connecting portion g of the joint member f, and the adhesive is provided in the gap between the inner peripheral surface of the connecting portion g and the spiral tube a. h is filled and hardened and fixed, and has the same hardness as or higher than the hardness of the coating material of the cable inserted into the spiral tube a in the gap between the end edge of the spiral tube a and the abutting portion of the joint member f. There has been proposed a connection structure between a spiral tube a filled with a filler i having a low hardness and a joint member f.

However, in the conventional connection structure as described above, even if it is possible to prevent damage to the cable protection tube and the cable at the time of connection, when bending stress acts in the vicinity of the connection structure after connection. Since the joint member f and the adhesive h layer are not flexible enough to absorb the stress, the bending stress concentrates on the portion of the spiral tube a near the connection portion, and the portion is easily damaged. There is a problem that it is not possible to exert such a waterproof effect.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, does not concentrate bending stress on the cable protection tube near the connection portion, and is excellent in waterproofness without damage. The purpose of the present invention is to provide a joint for a cable protection pipe that can be used by connecting the cable protection pipe in a state.

[0007]

According to the present invention, a pipe connecting portion for connecting a cable protection pipe is provided at an end of a pipe joint body,
This is a joint for a cable protection pipe, in which an extension portion made of a rubber elastic body is provided at a tip end portion of an outer tubular portion forming the pipe connection portion.

In the present invention, examples of the material forming the pipe joint body include hard synthetic resins such as hard polyvinyl chloride. In the present invention, examples of the cable protection pipe to be connected include a spiral pipe and a corrugated pipe.

In the present invention, examples of the material of the rubber elastic body include natural rubber, butadiene rubber, and styrene.
Butadiene rubber, acrylonitrile-butadiene rubber,
Examples of the elastic material include synthetic rubber such as chloroprene rubber, butyl rubber, silicon rubber, fluororubber and acrylic rubber.

[0010]

In the cable protection pipe joint of the present invention, a pipe connection portion for connecting the cable protection pipe is provided at an end portion of the pipe joint body, and a rubber elastic body is provided at a tip end portion of an outer cylinder portion forming the pipe connection portion. Since the extension part is provided, it is provided at the tip of the outer tube part of the pipe joint body when bending stress is applied near the pipe connection part of the pipe joint body of the cable protection pipe. The extending portion made of the rubber elastic body is bent so as to prevent the portion near the connecting portion of the cable protection tube from being sharply bent, so that the portion is not damaged and the waterproof property is secured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partially cutaway front view showing an example of a socket-type cable protection pipe joint of the present invention.

Reference numeral 1 is a tubular pipe joint body made of a hard synthetic resin such as hard polyvinyl chloride, and both ends thereof are
A pipe connection portion 11 for connecting the cable protection pipe 3 such as a spiral pipe or a corrugated pipe is provided. The pipe connecting portion 11 includes an outer tubular portion 111, a projecting portion 112 that is provided at a central portion of the pipe joint body 1 so as to project inward in a circumferential direction, and a substantially parallel to the outer tubular portion 111 from a tip edge of the projecting portion 112. It is formed of a short tubular portion 113 extending toward the opening. The gap between the outer tubular portion 111 and the short tubular portion 113 is substantially equal to the wall thickness of one end of the cable protection tube 3 to be connected.

When one end of the cable protection pipe 3 to be connected is inserted into the pipe connection portion 11 of the pipe joint body 1, one end surface of the cable protection pipe 3 is brought into contact with the side surface of the protruding portion 112. The tube end portion is fitted between the outermost outer cylinder portion 111 and the short cylinder portion 113 so that it can be prevented from coming off.

An extended portion 2 made of a rubber elastic body is provided at the tip of the outer cylinder portion 111 of the pipe joint body 1. The extending portion 2 has a ring shape having an inner and outer diameters that are substantially the same as those of the outer tubular portion 111 of the pipe joint body 1.

The mechanism in which the extending portion 2 is provided at the tip of the outer cylindrical portion 111 of the pipe joint body 1 is as follows. That is, on the tip end surface of the outer cylinder portion 111 of the pipe joint body 1, the groove 114 is provided so as to open laterally along the circumferential direction, and the groove 114 gradually widens as it goes deeper. It is said that it is spread out. A ridge 21 is provided on one end surface of the extending portion 2 so as to project laterally along the circumferential direction. Then, the projection 21 of the extension portion 2 is fitted into the concave groove 114 of the outer cylinder portion 111 of the pipe joint body 1, and the extension portion 2 is connected so as to extend on the extension line of the outer cylinder portion 111 of the pipe joint body 1. Has been done.

The mechanism in which the extension portion 2 is provided at the tip of the pipe connection portion 11 of the pipe joint body 1 is not limited to the above-mentioned mechanism, and is provided, for example, on one end face of the annular extension portion. The convex groove provided on the tip end surface of the pipe connecting portion 11 of the pipe joint body 1 may be fitted into the concave groove, or,
The end surface of one end of the annular extending portion 2 provided on the tip surface of the outer tubular portion 111 of the pipe joint body 1 may be fixed by an adhesive.

Next, an example of a usage mode in which the cable protection pipe 3 is connected to the pipe connection portion 11 of the socket type cable protection pipe joint 1 shown in FIG. 1 will be described with reference to FIG.

As shown in FIG. 2, a joint 1 for a cable protection pipe
Outer cylinder portion 111 forming the pipe connection portion 11 of the pipe joint body 1 of
One end of the cable protection pipe 3 is inserted into the pipe connecting portion 11 in which the extension portion 2 made of a rubber elastic body is provided at the tip end of the.

Then, one end surface of the cable protection tube 3 is brought into contact with the side surface of the projecting portion 112, and the tube end portion is fitted between the outermost cylindrical portion 111 and the short tubular portion 113 of the pipe connecting portion 11. Fix it by inserting it. This prevents one end of the cable protection tube 3 from coming out of the cable protection tube joint.

Further, when a bending stress is applied to the cable protection pipe 3 near the pipe connection portion 11 of the pipe joint body 1, a rubber provided at the tip of the outer cylinder portion 111 of the pipe joint body 1. The extension 2 made of an elastic material is bent so as to prevent the vicinity of the connection portion of the cable protection tube 3 from being sharply bent, so that the water protection is secured without damaging the portion.

FIG. 3 is a partially cutaway front view showing another example of the socket type cable protection pipe joint of the present invention.

Reference numeral 4 denotes a cylindrical pipe joint body made of synthetic resin, which is different from that described with reference to FIG. 1 except that a groove is not provided on the tip surface of the outer cylindrical portion. Since they are the same, only the corresponding drawing numbers are given in FIG. 3 and detailed description is omitted.

Outer cylinder portion 41 of the pipe connecting portion 41 of the pipe joint body 4.
An extension portion 5 made of a rubber elastic body is provided at the tip portion of 1. The shape of the extended portion 4 is such that the inner diameter of one end is slightly smaller than the outer diameter of the outer tubular portion 411 of the pipe joint body 4, and the inner diameter of the other end is substantially the same as the inner diameter of the outer tubular portion 411 of the pipe joint body 4. The inner surface of the central portion, which is the same, has an inclined surface, and has an annular shape with a predetermined thickness.

The mechanism for providing the extending portion 5 to the tip of the outer cylindrical portion 411 of the pipe joint body 4 is as follows.
That is, one end of the extending portion 5 is mounted on the outer periphery of the tip end portion of the outer tubular portion 411 of the pipe joint body 4, and the other end is provided so as to extend on the extension line of the outer tubular portion 411 of the pipe joint body 4. ing.

Next, an example of a mode of use in which the cable protection pipe 3 is connected to the pipe connecting portion 41 of the socket type cable protection pipe joint 4 shown in FIG. 3 will be described with reference to FIG.

As shown in FIG. 4 (see FIG. 3), an extension portion made of a rubber elastic body is provided on the outer periphery of the tip end portion of the outer cylindrical portion 411 forming the pipe connection portion 41 of the pipe joint body 41 of the cable protection pipe joint 4. 5 in the pipe connection portion 41 with one end attached,
Insert one end of the cable protection tube 3.

Then, one end surface of the cable protection tube 3 is brought into contact with the side surface of the projecting portion 412, and the tube end portion is fitted between the outermost cylindrical portion 411 and the short cylindrical portion 413 of the pipe connecting portion 41. Fix it by inserting it. As a result, one end of the cable protection pipe 3 does not come out of the cable protection pipe joint 4.

Further, when a bending stress is applied to the cable protection pipe 3 near the pipe connection portion 41 of the pipe joint body 4, a rubber provided at the tip of the outer cylindrical portion 411 of the pipe joint body 41. Since the other end portion of the extension portion 5 made of an elastic body is bent to prevent the vicinity of the connection portion of the cable protection tube 3 from being sharply bent, the portion is not damaged and the waterproof property is secured. It

[0029]

EFFECTS OF THE INVENTION Since the cable protection pipe joint of the present invention is constructed as described above, the cable protection pipe in the vicinity of the connecting portion is kept in an excellent water-proof state without being damaged due to bending stress concentration. Cable protection tube can be connected.

[0030]

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing an example of a joint for a cable protection pipe of the present invention.

FIG. 2 is a partially cutaway front view for explaining an example of a use mode of the cable protection pipe joint shown in FIG.

FIG. 3 is a partially cutaway front view showing another example of the cable protection pipe joint of the present invention.

FIG. 4 is a partially cutaway front view for explaining an example of a use mode of the cable protection pipe joint shown in FIG.

FIG. 5 is a cross-sectional view showing an example of a spiral tube.

FIG. 6 is a cross-sectional view illustrating a conventional connection structure between a spiral pipe and a joint member.

[Brief description of reference numerals]

 1,4 Pipe joint body 2,5 Extension part 3 Cable protection pipe

Claims (1)

[Claims] 1. A pipe connecting portion for connecting a cable protection pipe is provided at an end portion of a pipe joint body, and an extension portion made of a rubber elastic body is provided at a tip end portion of an outer cylinder portion forming the pipe connecting portion. A joint for a cable protection pipe, which is characterized in that