JP2008312295A - Connecting structure between sheath tube for communication cable and side wall of handhole - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting structure between a sheath tube and a side wall of a handhole that prevents a sheath tube from protruding into a handhole together with a fixing plate or prevents a sheath tube from being detached from a sleeve while allowing axial thermal-expansion/contraction of a sheath tube and allowing movement of a sheath tube when an earthquake occurs, and a joint used for the connection. <P>SOLUTION: The connecting structure is a connecting structure between a sheath tube 2 inserted with a communication cable and a side wall 4a of a handhole 4 buried in the ground. A sleeve 13 is fixed onto the side wall 4a of the handhole 4 while the end of the sheath tube 2 is connected to the sleeve 13 via a joint 1. The joint 1 has a first tube 11 and a second tube 12 axially movably fitted to the first tube 11. A coil spring 10 is externally fitted to the first tube 11 and the second tube 12. One end of the coil spring 10 is fixed to the first tube 11 while the other end of the coil spring 10 is fixed to the second tube 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a sheath tube for protecting a cable and a handhole for relaying the cable inserted into the sheath tube when a communication cable such as a power line, a telephone line, and an optical fiber cable is buried in the ground. It is related with the connection structure with the side wall which comprises.

  Inside the large-diameter main body pipe buried in the ground, a plurality of small-diameter sheath pipes with optical communication cables inserted are inserted to form an optical communication conduit, and a network with optical communication cables is constructed to create information Communication is performed.

  According to this method, a large number of optical communication cables can be laid in the main tube, so that the labor for excavation and the like can be reduced. Therefore, the construction period can be shortened and the cost can be reduced. It has come to be.

  Usually, in such optical communication pipelines, points where necessary work such as inspection of installed optical communication cables, connection or branching with separately installed optical communication cables, or change of installation direction are performed. Hand holes are provided. JP 2000-261945 A (Patent Document 1), JP 9-229261 A (Patent Document 2), JP 2006-246638 A (Patent Document 3).

    Although the sheath tube 2 is disposed between the hand holes 4, the sheath tube 2 expands and contracts due to a change in temperature or the like. As a method of connecting the optical communication conduit to the hand hole 4, for example, FIG. 8 and FIG. 9, an opening 8 is provided in the side wall 4 a of the hand hole 4 buried in the ground, and a sleeve 13 is attached to the solid plate 6 fixed to the opening 8, and the sheath tube 2 is axially attached to the sleeve 13. Is inserted to be movable. In the figure, reference numeral 16 denotes a main pipe into which a plurality of sheath pipes 2 are inserted.

  With such a configuration, thermal expansion and contraction in the axial direction of the sheath tube 2 is allowed, and movement along the axial direction of the sheath tube 2 is allowed when an earthquake occurs.

However, as shown in FIG. 10, troubles such as the sheath tube 2 protruding into the hand hole 4 together with the fixing plate 6 and the end of the sheath tube 2 coming off from the sleeve 13 have occurred in various parts of the country. For this reason, force or bending is applied to the optical communication cable, which may adversely affect transmission characteristics, and the core wire may be broken.
JP 2000-261945 A JP-A-9-229261 JP 2006-246638 A

  The present invention has been made to eliminate the above-mentioned drawbacks, and its purpose is to allow thermal expansion and contraction of the sheath tube in the axial direction and allow movement of the sheath tube when an earthquake occurs, To provide a connection structure between a sheath tube and a side wall of a hand hole, and a joint used for the connection, which can prevent the sheath tube from protruding together with the fixing plate into the hand hole or from coming off the sleeve. .

  Another object of the present invention is to provide a connection structure having a small number of work steps for piping work and excellent workability, and a joint used for the connection.

  In the connection structure between the sheath tube through which the communication cable of the present invention is inserted and the side wall of the hand hole embedded in the ground, a sleeve is fixed to the side wall of the hand hole, and the end of the sheath tube is connected to the sleeve. The joint has a first pipe and a second pipe fitted to the first pipe so as to be movable in the axial direction, and the first pipe and the second pipe are connected to each other. A coil spring is externally fitted, one end of the coil spring is fixed to the first tube, and the other end of the coil spring is fixed to the second tube, thereby achieving the above object.

  In one embodiment, an opening is formed in the side wall of the hand hole, a fixing plate is attached to the side wall so as to seal the opening, and the sleeve is inserted and fixed in a through hole formed in the fixing plate. Has been.

  In one embodiment, the first tube includes an outer tube and an inner tube having a slightly smaller diameter than the outer tube, and one end of the inner tube is inserted and fixed in the outer tube, and the inner tube is in the second tube. Is inserted to be movable.

  In one embodiment, the outer tube is provided with a protrusion projecting inward to restrict the movement of the inner tube.

  The joint of the present invention is a joint connected between a sheath pipe through which a communication cable is inserted and a side wall of a handhole buried in the ground, the joint comprising the first pipe, the first pipe, A second tube movably fitted in one tube so as to be movable in the axial direction, and a coil spring is externally fitted to the first tube and the second tube, and one end of the coil spring is attached to the first tube. The other end of the coil spring is fixed to the second tube, thereby achieving the above object.

  In one embodiment, the first tube is connected to a sleeve connected to the side wall of the handhole.

  Many of the causes of troubles such as the information box tube (sheath tube) sticking together with the fixing plate in the hand hole and the sleeve and sheath tube coming off are the creeping phenomenon. It seems that there are many cases. The creeping phenomenon is a phenomenon in which the entire cable or the core wire moves due to vibration or temperature change caused by passage of a large vehicle or the like. In particular, the occurrence of creeping phenomenon is significant where large vehicles pass on soft ground, where there are many vehicles passing on slopes, and where the road surface is uneven.

  On a general road, if there is a cable under the road surface on which the vehicle travels, cable movement due to creeping phenomenon is likely to occur. The creeping phenomenon often occurs in the inclination of the road in the longitudinal direction and the traveling direction of the vehicle.

  According to the present invention, the sleeve is fixed to the side wall of the handhole, the end of the sheath pipe is connected to the sleeve via the joint, and the joint moves in the axial direction to the first pipe and the first pipe. A second tube 12 that can be fitted, a coil spring is externally fitted to the first tube and the second tube, and one end of the coil spring is fixed to the first tube. Since the other end portion is fixed to the second pipe, the movement of the sheath pipe in the axial direction is allowed by the joint, and the sheath pipe can be returned to the original position by the coil spring.

  Therefore, since the sheath tube can be prevented from moving greatly, even when the above creeping phenomenon occurs, the sheath tube protrudes into the hand hole together with the fixing plate, or the sheath tube is detached from the sleeve. The transmission characteristics of the optical communication cable can be prevented, and the core wire is not broken.

  Embodiments of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 to 5, the connection structure between the sheath tube 2 through which the communication cable of the present invention is inserted and the side wall 4 a of the hand hole 4 buried in the ground is as follows.

  The pipe connection structure includes a long sheath tube 2 and a plurality of box-shaped hand holes 4 to which the sheath tube 2 is connected.

  The sheath tube 2 is formed of a synthetic resin material having flexibility and heat stretchability, such as polyvinyl chloride, and is stored so as to protect the cable from, for example, ground water when the optical communication cable is embedded in the ground. It is used as a protective tube.

  The hand hole 4 is defined by a side wall 4a formed of, for example, reinforced concrete, and checks the optical communication cable inserted into the sheath tube 2, branches, connection of the optical communication cable and other optical communication cables, and the like. Therefore, they are provided at predetermined intervals in the wiring path of the optical communication cable.

  As shown in FIG. 8, the sheath tube 2 is disposed between the hand holes 4 and is connected to the side walls 4 a of the hand holes 4 at both ends thereof.

  A sleeve 13 for connecting the sheath tube 2 to the side wall 4 a is provided on the side wall 4 a of the hand hole 4.

  The sleeve 13 is made of, for example, a tube member made of a synthetic resin material similar to that of the sheath tube 2, and is provided on the side wall 4 a of the hand hole 4 so as to linearly extend from the side wall 4 a to the side thereof.

  A side wall 4 a of the hand hole 4 is buried in the ground, and a sleeve 13 is fixed to the side wall 4 a of the hand hole 4. That is, the opening 8 is formed in the side wall 4 a of the hand hole 4, the fixing plate 6 is fixed to the opening 8, and the sleeve 13 is fixed to the fixing plate 6. A through hole is formed in the fixed plate 6, and a cylindrical sleeve 13 is inserted into the through hole, and the end of the sleeve 13 is fixed to the fixed plate 6.

  The end portion of the sheath tube 2 is connected to the sleeve 13 via the joint 1.

  The joint 1 includes a first pipe 11 and a second pipe 12 that is fitted to the first pipe 11 so as to be movable in the axial direction. The first pipe 11 and the second pipe 12 are connected to each other. A coil spring 10 is externally fitted, one end of the coil spring 10 is fixed to the first tube 11, and the other end of the coil spring 10 is fixed to the second tube 12.

  The first tube 11 and the second tube 12 are composed of one or more tube members. In this embodiment, the first tube 11 includes an outer tube 11a and an inner tube 11b having a slightly smaller diameter than the outer tube 11a. And one end of the inner tube 11b is inserted and fixed in the outer tube 11a. The outer tube 11a has a protruding portion 15 projecting inward to restrict the movement of the inner tube 11b. The outer tube 11a and the inner tube 11b can be fixed by, for example, an adhesive or melting by heating.

  The second tube 12 is formed to have a slightly larger diameter than the inner tube 11b so as to externally fit the inner tube 11b. By inserting the other end of the inner tube 11 b into the second tube 12, the inner tube 11 b can move within the second tube 12 within a predetermined expansion and contraction range in the axial direction. Further, the second pipe 12 has a protruding portion 12a projecting inward to restrict the movement of the inner pipe 11b beyond the expansion and contraction. The length of the expansion / contraction margin is, for example, 50 mm to 150 mm, preferably 70 mm to 100 mm, although it depends on the length of the sheath tube 2 and the material constituting the sheath tube 2. In that case, it is preferable that the length in which the inner tube 11b and the second tube 12 overlap is also approximately the same size as the expansion and contraction.

  A coil spring 10 is fitted around the first tube 11 and the second tube 12, one end of the coil spring 10 is fixed to the first tube 11, and the other end of the coil spring 10 is attached to the second tube 12. The first tube 11 and the second tube 12 and the coil spring 10 can be fixed with a known fixing tool such as a tape or an adhesive.

  When the sheath tube 2 expands or contracts due to heat or due to an earthquake or the like, the inner tube 11b and the outer tube 11a overlap with each other in the range of expansion and contraction, so that the sheath tube 2 is allowed to expand and contract. be able to. Further, when a creeping phenomenon occurs, a force for moving the sheath tube 2 back to the original position by the coil spring 10 acts so that the sheath tube 2 does not move greatly.

  6 and 7 illustrate a repair method for a pipe line in which a cable has already been inserted.

  The sheath tube 2, the sleeve 13 and the joint 1 that do not contain the cable are arranged in parallel to the sheath tube 22 and the sleeve 23 that contain the cable, the sleeve 13 is connected to the fixing plate 6, and both the sheath tubes 2, 22 Are connected by a metal fitting 14. By configuring in this way, the movement of the sheath tube 22 containing the cable can be regulated by the coil spring 10 via the coupling hardware 14.

  With such a configuration, when the creeping phenomenon occurs, the sheath tube 22 and the sleeve 23 are damaged by the force acting on the sleeve 23 from the sheath tube 22, and the sleeve 13 from the sheath tube 22 to the side wall 4 a defining the hand hole 4. It is possible to reliably prevent the protrusion and the side wall 4a from being damaged due to the force acting through the.

  As mentioned above, although the Example of this invention was described along drawing, the specific structure is not restricted to an above-described structure, The structure by which the design change of the range which does not deviate from the summary of this invention is also contained in this invention. .

  For example, in the above embodiment, the joint 1 is constituted by the first pipe (the outer pipe 11a, the inner pipe 11b), the second pipe 12, and the coil spring 10, but the outer pipe 11a and the inner pipe 11b are integrally formed. May be.

  Further, although the sleeve 13 and the sheath tube 2 are connected by the joint 1, the sleeve 13 and the sheath tube 2 may be overlapped and connected by the coil spring 10. Two joints 1 may be connected to both ends of the sheath tube 2, respectively.

It is a front view of the connection structure of one Example of this invention. It is a front view of the connection structure of one Example of this invention. It is a front view of the 1st pipe | tube and 2nd pipe | tube of the coupling shown in FIG. It is a front view which shows the state which connected the outer pipe, the inner pipe, and the 2nd pipe | tube of the joint shown in FIG. FIG. 3 is a front view of the joint illustrated in FIG. 2. It is explanatory drawing of the other Example of this invention. It is an enlarged view of the connection structure shown in FIG. It is explanatory drawing of the conventional pipe line. It is a figure explaining the conventional problem. It is a figure explaining the conventional problem.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Joint 2 Sheath pipe 4 Hand hole 6 Fixing plate 8 Opening part 10 Spring 11 First pipe 12 Second pipe 13 Sleeve

Claims (6)

A connection structure between a sheath tube through which a communication cable is inserted and a side wall of a handhole buried in the ground,
A sleeve is fixed to the side wall of the handhole, and an end portion of the sheath tube is connected to the sleeve via a joint. The joint is fitted to the first tube and the first tube so as to be movable in the axial direction. A coil spring is externally fitted to the first pipe and the second pipe, one end of the coil spring is fixed to the first pipe, and the other end of the coil spring is A connection structure fixed to the second tube. 2. An opening is formed in a side wall of the handhole, a fixing plate is attached to the side wall so as to seal the opening, and the sleeve is inserted and fixed in a through hole formed in the fixing plate. The connection structure described in 1. The first pipe is composed of an outer pipe and an inner pipe having a slightly smaller diameter than the outer pipe. One end of the inner pipe is inserted and fixed in the outer pipe, and the inner pipe is movably inserted into the second pipe. The connection structure according to claim 1. The connection structure according to claim 3, wherein the outer pipe is provided with a projecting portion protruding inward to restrict movement of the inner pipe. A joint connected between a sheath tube through which a communication cable is inserted and a side wall of a handhole buried in the ground,
The joint includes a first pipe and a second pipe that is fitted to the first pipe so as to be movable in the axial direction, and a coil spring is externally fitted to the first pipe and the second pipe. A joint in which one end of the coil spring is fixed to the first pipe and the other end of the coil spring is fixed to the second pipe. The joint according to claim 5, wherein the first pipe is connected to a sleeve connected to a side wall of the handhole.

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