JP2023086826A - Cable protection conduit member and cable protection conduit - Google Patents

Abstract

To provide a cable protection conduit member capable of easily carrying out a joint work of cable protection conduit members and a shape change of the cable protection conduit.SOLUTION: A cable protection conduit member 250 according to the present invention is provided with a linear cable protection pipe 5, and a fitting 21 connected to an end portion 7 of the cable protection pipe. Each of sockets 41 and 42 of the fitting is provided with: a socket fulcrum portion 102 arranged inside in the radial direction B at a midway position in the pipe axis direction A; a first diameter expansion portion 51 expanding diameter from the socket fulcrum portion toward a main pipe 31 in the pipe axis direction, and a second diameter expansion portion 52 expanding diameter from the socket fulcrum portion as going away from the main pipe 31 in the pipe axis direction. A effective length M of the cable protection conduit member according to the present invention is 600 mm or more and 5600 mm or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cable protection conduit member and a cable protection conduit.

2. Description of the Related Art In recent years, in order to improve scenery, prevent disasters, etc., undergrounding of cables such as electric wires and equipment related to the cables underground (removal of utility poles) has been promoted. When electric wires are laid underground, a plurality of cables are housed in a cable protection tube in a state of being inserted directly or into sheath pipes. A large number of such cable protection pipes are connected and buried in the ground to form a cable protection conduit.

For example, Patent Literature 1 discloses a cable protection conduit in which a plurality of cable protection tubes are connected to each other by a joint member having a plurality of bendable portions.

JP 2017-163627 A

Conventionally, the radius of curvature of the bent portion of the cable protection conduit was set to 5 m or more in order to prevent the cable or sheath tube from being damaged due to excessive curvature. In practice, a so-called 5 mR bent pipe with a minimum curvature radius of 5 m or a 10 mR bent pipe with a minimum curvature radius of 10 m is used for the bent portion of the cable protection conduit.

However, when constructing the cable protection conduit by connecting the cable protection tube with a bent tube after inserting the sheath tube inside, it is necessary to prevent the curvature of the cable and sheath tube from becoming excessively large as described above. It was necessary to align the tube axis of the socket on the side with the tube axis of the straight tube and insert the straight tube straight into the socket. In order to insert the straight pipe straight into the socket in this manner, special jigs and skill of the operator are required.
In addition, when an existing buried object is found during excavation work for burying the cable protective pipe, the design of the cable protective pipe must be changed so as to avoid the buried object. In the past, different straight pipes and curved pipes were used before and after the design change of the cable protection conduit, and it took time and effort to procure the pipe material after the design change.
That is, conventionally, there has been a problem that it is difficult to connect cable protection conduit members and to change the shape of the cable protection conduit.

SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and provides a cable protection conduit member and a cable protection conduit that facilitate connection work between cable protection conduit members and modification of the shape of the cable protection conduit. do.

A cable protection conduit member of the present invention includes a straight cable protection tube and a joint connected to the cable protection tube, wherein the joint is provided at one end of the main tube and the main tube. and a second socket provided at the other end of the main pipe, wherein the first socket and the second socket are aligned with the main pipe axis of the main pipe. a socket fulcrum provided at an intermediate position in the axial direction of the main pipe along the main pipe; a second expanded diameter portion that expands in diameter from the socket fulcrum portion along the main pipe axial direction as it separates from the main pipe, wherein the main pipe axis and the protection tube axis of the cable protection tube are aligned on a straight line. Another cable protection tube having the same outer diameter as the cable protection tube is inserted into the second receptacle from the end of the cable protection tube opposite to the end fitted to the joint in a state where it overlaps with the An effective length to a position where the tip of the separate cable protection tube can be reached when inserted is 600 mm or more and 5600 mm or less.

According to the above configuration, the cable protection tube and the joint are a set, the cable protection tube is formed linearly, and the first socket and the second socket of the joint are connected with the socket fulcrum as a fulcrum. A cable protection tube inserted into a socket is made rotatable about a main tube axis. When connecting cable protection tube members to each other, if the tube axis of the cable protection tube (hereinafter sometimes referred to as the protection tube axis) and the main tube axis are aligned in a straight line to straighten the entire cable protection tube member, It becomes easier to straightly insert the cable protection tube of another cable protection conduit member into the joint of one cable protection conduit member. In this way, for example, after inserting the sheath tube inside, the cable protection tube can be easily inserted straight into the joint while keeping the curvature of the sheath tube small. Further, by adjusting the diameter expansion angles of the first enlarged diameter portion and the second enlarged diameter portion of the first socket and the second socket in consideration of the effective length, after the cable protection conduit members are connected to each other, The cable protection tube and the joint can be rotated about the socket fulcrum portion with respect to the protection tube axis and the main tube axis. As a result, it is possible to easily change the shape of the cable protection conduit according to the position of existing buried objects, roads, etc. while keeping the curvature of the sheath pipe within a predetermined range.

In the cable protection conduit member of the present invention, in the first socket, the diameter expansion angle of the first diameter expansion portion with respect to the main pipe axis and the diameter expansion angle of the second diameter expansion portion with respect to the main pipe axis Among them, the smaller diameter expansion angle is defined as the first diameter expansion angle, and in the second receiving port, the diameter expansion angle of the first diameter expansion portion with respect to the main pipe axis and the diameter expansion angle of the first diameter expansion portion with respect to the main pipe axis and the second expansion angle with respect to the main pipe axis The sum of the first diameter expansion angle and the second diameter expansion angle is preferably 24° or less when the smaller diameter expansion angle among the diameter expansion angles of the diameter portion is defined as the second diameter expansion angle. preferable.

According to the above configuration, the protection tube axis of the cable protection tube inserted into the second socket can be inclined up to 24° with respect to the protection tube axis of one cable protection conduit member. When connecting a plurality of cable protection conduit members, the cable protection conduit can be bent appropriately.

In the cable protection conduit member of the present invention, a stopper portion is provided at an end portion of at least one of the first socket and the second socket on the main pipe side, and the stopper portion has flexibility and the It preferably protrudes radially inward.

According to the above configuration, the end of the protective tube inserted into at least one of the first socket and the second socket abuts against the stopper and is stabilized, resulting in extra margin for insertion. Therefore, when a force acts on the cable protection conduit member in the axial direction of the protection tube, the stopper portion is deformed, and the cable protection tube can move within the margin for insertion.

The cable protection conduit of the present invention includes a plurality of cable protection conduit members as described above, and the cable protection conduit member of another cable protection conduit member up to the protection tube insertion position of the second socket of one of the cable protection conduit members. The cable protection tube is inserted into the other end of the cable protection tube in the axial direction of the protection tube.

According to the above-described configuration, after inserting the sheath tube into the inside of one cable protection conduit member, the curvature of the sheath tube is kept small, and the cable protection tube of another cable protection conduit member is inserted into one cable. It can be easily inserted straight into the second receptacle of the protective conduit member. In addition, by rotating the cable protection pipe and joint around the socket fulcrum, the shape of the cable protection pipe can be adjusted according to the existing buried objects, the position of the road, etc. while keeping the curvature of the sheath pipe within a predetermined range. can be easily changed.

In the cable protection conduit of the present invention, the distance between the socket fulcrum portion of the first socket and the socket support part of the second socket in the axial direction of the main pipe is 400 mm or more and 600 mm or less. preferable.
More preferably, in the cable protection conduit of the present invention, the effective length is 1000 mm or 2000 mm.

According to the above configuration, the curvature of the sheath tube is kept within a predetermined range, the length of the cable protection tube is set at several meters for ease of handling, and the cable protection tube has the minimum curvature radius specified for the communication cable. It can be bent freely within the range of 5m or 10m.
For example, if the maximum bending angle is 24°, the effective length can be 1 m to achieve a minimum radius of curvature of 5 m, and the effective length can be 2 m to achieve a minimum radius of curvature of 10 m. can.

According to the cable protection conduit member and the cable protection conduit according to the present invention, it is possible to easily connect the cable protection conduit members and change the shape of the cable protection conduit.

1 is a cross-sectional view of a cable protection conduit member according to one embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view of a portion of the cable protection conduit member shown in FIG. 1; FIG. 3 is a cross-sectional view of the joint taken along line II shown in FIG. 2; 1 is a cross-sectional view of a cable protection conduit according to one embodiment of the invention; FIG. Fig. 5 is a cross-sectional view of a joint of the cable protection conduit member shown in Figs. 1 and 4; 5 is a cross-sectional view of part of a cable protection conduit member of the cable protection conduit shown in FIG. 4; FIG. Fig. 5 is a cross-sectional view of a joint of the cable protection conduit member shown in Figs. 1 and 4;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a cable protection conduit member and a cable protection conduit of the present invention will be described with reference to the drawings.

[Structure of Cable Protection Conduit Member]
As shown in FIG. 1, the cable protection conduit member 250 of the present embodiment has flexibility, and has a straight cable protection tube 5 and a tube axis (protection tube axis) J5 of the cable protection tube 5. and a joint 21 connected to an end (one end of the protective tube) 7 in the tube axial direction (protective tube axial direction) F. The joint 21 includes a main pipe, a socket (first socket) 42 and a socket (second socket) 41 .

The socket 42 is provided at an end (one main pipe end) 32 in a pipe axial direction (main pipe axial direction) A along the pipe axis (main pipe axis) J31 of the linear main pipe 31 . The end portion 7 can be inserted into the receptacle 42 . The cable protection conduit member 250 is configured by a set of one cable protection tube 5 and the joint 21 with the end portion 7 inserted into the socket 42 .

The socket 41 is provided at an end portion (the other main pipe end portion) 33 of the main pipe 31 in the pipe axis direction A. As shown in FIG. The end (the other end of the protection tube) 6 in the tube axis direction F of the cable protection tube 5 of another cable protection conduit member 250 can be inserted into the socket 42 up to the protection tube insertion position 260 .

As shown in FIGS. 1 and 2, the sockets 41 and 42 include a socket support portion 102, a first enlarged diameter portion 41, a first reduced diameter portion 53, and a second enlarged diameter portion 42. ing. The socket support portion 102 bulges outward in a radial direction B perpendicular to the pipe axis direction J31. A concave portion 107 is formed in the socket support portion 102, and an elastic member 64 such as a rubber ring is fitted in the concave portion 102. As shown in FIG. With the outer peripheral surface of the cable protection tube 5 in contact with the elastic member 64, the ends 6 and 7 are stably supported inside the sockets 41 and 42. As shown in FIG.

The diameter of the first enlarged diameter portion 51 increases from the main pipe 31 side end of the socket support portion 102 toward the main pipe 31 along the pipe axis direction A. As shown in FIG. The angle formed by the first enlarged diameter portion 51 with respect to the tube axis J31 is preferably 3° or more and 12° or less, more preferably 5.5° or more and 6° or less, for example 5.75°. be.

The first diameter-reduced portion 53 extends from the main pipe 31 side end of the first diameter-enlarged portion 51 to the main pipe 31 and decreases in diameter as it approaches the main pipe 31 along the pipe axial direction A. As shown in FIG.

A stopper portion 58 is interposed between the first enlarged diameter portion 51 and the first reduced diameter portion 53 of the socket 41 . The stopper portion 58 is flexible and protrudes inward in the radial direction B. As shown in FIG. An inner peripheral surface of the stopper portion 58 functions as a stopper surface 75 .

At the socket 42, the first enlarged diameter portion 51 and the first reduced diameter portion 53 are directly connected. A stopper portion 58 similar to the socket 41 may be interposed between the first enlarged diameter portion 51 and the first reduced diameter portion 53 of the socket 42 . From the viewpoint of securing extra margin for insertion of the cable protection tube 5 , it is preferable that a stopper portion 58 is provided in at least one of the sockets 41 and 42 .

As shown in FIG. 3, two or more stopper portions 58 are provided at intervals in the circumferential direction C around the tube axis J31. FIG. 3 shows an example in which four stopper portions 58 are provided in the circumferential direction C of the socket 41 . Note that the stopper portion 58 may be provided in the entire circumferential direction C. As shown in FIG. The size of the stopper portion 58 in the circumferential direction C and the proportion of the stopper portion 58 in the circumferential direction C are not particularly limited, and are appropriately determined.

An end surface 125 of the cable protection tube 5 is provided with a contact surface 127 which is inclined at a predetermined angle with respect to the tube axis J31. The contact surface 127 is formed on the outer side in the radial direction B of the end surface 125 . Further, the contact surface 127 is arranged with respect to the tube axis J31 so as to move away from the main pipe 31 as it progresses from the inner side to the outer side in the radial direction B so as to easily contact the stopper surface 75 that bulges inward in the radial direction B. slanted at a predetermined angle.

As shown in FIG. 1 , in the socket 42 , the contact surface 127 of the end portion 7 contacts the inner peripheral surface of the first reduced diameter portion 53 . When the cable protection tube 5 of another cable protection conduit member is inserted into the socket 41, the contact surface 127 of the end portion 6 contacts the stopper surface 75 of the stopper portion 58, as shown in FIG.

The second enlarged diameter portion 52 extends from the end of the first bulging portion 61 on the side opposite to the main pipe 31 side along the pipe axis direction A away from the main pipe 31 and ends 137 . expands as it approaches The angle formed by the second enlarged diameter portion 52 with respect to the tube axis J31 is preferably 3° or more and 12° or less, and is preferably 5.5° or more and 6° or less, similarly to the first enlarged diameter portion 51. is more preferred, for example 5.75°.

In the sockets 41 and 42, the diameter expansion angle of the first diameter expansion portion 51 with respect to the tube axis J31, that is, the inclination angle, and the diameter expansion angle of the second diameter expansion portion 52 are preferably equal. In that case, the diameter expansion angle of the first diameter expansion portion 51 and the diameter expansion angle of the second diameter expansion portion 52 becomes the minimum diameter expansion angle. When the diameter expansion angles of the first diameter expansion portion 51 and the diameter expansion angle of the second diameter expansion portion 52 are different from each other, the smaller diameter expansion angle is the minimum diameter expansion angle. The minimum diameter expansion angle is the maximum rotation angle at which the cable protection tube 5 can rotate about the socket support portion 102 with respect to the main tube axis J31. The minimum diameter expansion angle of the first enlarged diameter portion 51 or the second enlarged diameter portion 52 of the socket 42 with respect to the tube axis J31 and the angle of the first enlarged diameter portion 51 or the second enlarged diameter portion 52 of the socket 41 with respect to the tube axis J31 The sum with the minimum expansion angle is 24° or less, preferably 11.5° or less.

The distance between the socket fulcrum part 102 of the socket 42 of one joint 26 and the socket support part 102 of the socket 41 in the pipe axis direction J31 is preferably 200 mm or more and 600 mm or less, and is 300 mm or more and 500 mm or less. is more preferred.

As a material for the cable protection tube 5 and the joint 26, a flexible and elastically deformable resin is preferable, such as polyvinyl chloride (PVC).

[Structure of Cable Protection Conduit]
As shown in FIG. 4, the cable protection conduit 4 of the present invention includes a plurality of cable protection conduit members 250 described above, which are connected. In the cable protection conduit 4, the end of the cable protection tube 5 of another cable protection conduit member 250-2 in the tube axis direction J5 reaches the protection tube insertion position 260 of the socket 41 of one cable protection conduit member 250-1. part (the other protective tube end part) 6 is inserted.

The cable protection conduit 4 is used for undergrounding the cable 1 such as an electric wire in order to protect the landscape by eliminating utility poles. The cable protection conduit 4 is constructed, for example, in a state in which a plurality of manholes (not shown) are buried in the ground of a road or the like with a required interval, and the cable protection conduit 4 extends laterally between these manholes, that is, along the horizontal direction. installed to connect.

The cable protection tube 5 corresponds to, for example, what is called a body tube or a free access tube. When used as a body tube, as shown in FIG. 5, a plurality of sheath tubes 2 accommodating cables 1 are housed inside the cable protection tube 5 together. The nominal diameter of the body tube is relatively large, ranging from 150 (outer diameter approximately 165 mm) to 250 (outer diameter approximately 267 mm).

FIG. 4 shows that the cable protection conduit 4 is bent and the tube axes J5 and J31 are not on the same straight line. As shown in FIG. 1, in a state in which the tube axes J5 and J31 are aligned with each other, the ends of the cable protection tube 5 of the cable protection conduit member 250 (cable Another cable protection tube having the same outer diameter as that of the cable protection tube is inserted into the protection tube insertion position (second receptacle) from the end face 125 of the protection tube 6 (the end opposite to the end fitted in the joint of the protection tube). The effective length M up to the position 260 configured so that the tip of another cable protection tube can reach when be done. Considering the case where the minimum radius of curvature of the cable protection conduit 4 is 5 m or 10 m as defined for communication cables or the like, the effective length M is preferably 600 mm or more and 5600 mm or less.

When the sum of the minimum diameter expansion angle of the first enlarged diameter portion 51 or the second enlarged diameter portion 52 of the sockets 41 and 42 with respect to the tube axis J31 is 24° or less, the effective length M is 1000 mm or 2000 mm. is more preferred. In the above case, for example, the effective length M that achieves the minimum radius of curvature of 5 m is 1000 mm, and the effective length M that achieves the minimum radius of curvature of 10 m is 2000 mm.

As shown in FIG. 4, by setting the various angles and the effective lengths M described above, the pipe axis J5 of the cable protection tube 5 of each of the cable protection conduit members 250, 250-1, and 250-2 is aligned with the main pipe of the joint 21. 31 with respect to the tube axis J31 of 31 within the range of rotation angle θ around the socket support portion 102 . When the sum of the minimum diameter expansion angle of the first enlarged diameter portion 51 or the second enlarged diameter portion 52 of the socket 41 with respect to the pipe axis J31 is 24° or less, the sum of the rotation angles θ across the joint 21 is 24°. ° or less, the rotation angle γ between the cable protection tubes 5 sandwiching the joint 21 is 24° or less.

As shown in FIG. 6, the diameter d51 of the inner peripheral surface of the first enlarged diameter portion 51 depends on the distance x along the tube axis J31 from the center P of the rotation fulcrum 102 in the tube axis direction A. and is represented by the following equation (1).

(1) In the formula,
D: the diameter of the outer peripheral surface of the cable protection tube 5;
θ: the maximum value of the angle (narrow angle) between the tube axis J5 and the tube axis J31 of the cable protection tube 5 where one end in the circumferential direction of the outer peripheral surface is in contact with the inner peripheral surface of the first enlarged diameter portion 51; , the maximum bending angle between the cable protection tube 5 and the joint 25 (see FIG. 7),
is. The diameter D should be greater than or equal to the maximum manufacturing dimensional tolerance.

From the viewpoint of achieving a minimum radius of curvature of 5 m or 10 m, the rotation angle θ is greater than 0° and 11.5° or less, preferably 8° or less, and more preferably 6° or less. In the sockets 41 and 42 in the range where the ends 6 and 7 of the cable protection tube 5 are inserted, if the expression (1) is satisfied on either the main pipe 31 side or the end 137 side of the rotation fulcrum 102, the cable Rotation of the protective tube 5 is restricted. When the cable protection tube 5 rotates about the center P at the maximum rotation angle, the outer peripheral surface of the cable protection tube 5 comes into contact with the inner peripheral surfaces of the first enlarged diameter portion 51 and the second enlarged diameter portion 52 for cleaning.

For a suitable range of the rotation angle θ and the relationship represented by the formula (1), for example, a design example of the joint 21 when the cable protection tube 5 having an inner diameter of 150 mm (φ150) is used, see FIG. explain.

The diameter D of the φ150 cable protection tube 5 is, for example, 166 mm in consideration of the maximum manufacturing dimensional tolerance. Also, the length L0 of the second enlarged diameter portion 52 is 35 mm. The length L1 of the first enlarged diameter portion 51 of the socket 42 is 115 mm. The length L2 of the first enlarged diameter portion 51 of the socket 41 is 165 mm.

In the joint 21 of the design example described above, the inner diameter d0 of the end 137 is determined to be 174 mm by equation (1). The inner diameter d1 of the end of the main pipe 31 side of the first enlarged diameter portion 55 of the socket 42 is calculated to be 190 mm according to the equation (1). The inner diameter d2 of the end of the main pipe 31 side of the first expanded diameter portion 51 of the socket 41 is calculated to be 200 mm according to the equation (1).

For example, by designing the joint 21 with the diameters d0, d1, and d2 as upper limits, the angle θ is set to 5.75° or less, and the first enlarged diameter portion 51 or the second enlarged diameter portion The sum with the minimum diameter expansion angle of the portion 52 can be 24° or less. Thus, for example, the joint 21 can be easily designed using the diameters d0, d1, and d2 as reference values. Further, if the diameters d0, d1, and d2 are set as reference values, as shown in FIG. Along. In such a cable protection tube 4, the effective length N is 1000 mm, assuming that the distance on the arc of 5 mR between the centers of the tube axes J5 of the adjacent cable protection tubes 5 is the effective length N. Strictly speaking, the effective lengths M and N are different from each other, but since the radius of curvature R is as large as about 5000 mm or 10000 mm, the effective length N can be considered to be about the same as the effective length M.

[Effect]
The cable protection conduit member 250 of this embodiment described above includes the cable protection tube 5 and the joint 21 described above. The sockets 41 and 42 of the joint 21 include a socket fulcrum portion 102 , a first enlarged diameter portion 51 and a second enlarged diameter portion 52 . The effective length M of the cable protection conduit member 250 is 600 mm or more and 5600 mm or less.
According to the above configuration, the cable protection conduit member 250 includes the cable protection tube 5 and the joint 21 as a set, and an effective length M of 600 mm or more and 5600 mm or less is ensured. The cable protection tube 5 is formed in a straight line, and the sockets 41 and 42 of the joint 21 are inserted into these sockets 41 and 42 with the socket fulcrum portion 102 as a fulcrum. Make it rotatable. When the cable protection conduit members 250 are connected to each other, the tube axes J5 and J31 are aligned with each other, and the cable protection conduit member 250-1 is formed by straightening the entire cable protection conduit member 250 as shown in FIG. The end portion 6 of the cable protection tube 5 of the cable protection conduit member 250-2 can be inserted straight into the socket 41 of the cable protection conduit member 250-2. That is, after inserting the cable 1 and sheath tube 2 inside, the cable protection tube 5 can be easily inserted straight into the socket 41 while keeping the curvature of the cable 1 and sheath tube 2 small. Further, by adjusting the diameter expansion angles of the first enlarged diameter portion 51 and the second enlarged diameter portion 52 of the sockets 41 and 42 in consideration of the length and effective length M of the cable protection tube 5, the cable protection conduit can be After the members 250 are connected to each other, the cable protection tube 5 and the joint 21 can be rotated about the tube axes J5 and J31 with the socket fulcrum portion 102 as the center. As a result, the shape of the cable protection conduit 4 can be easily changed according to the existing buried objects, the position of the road, etc., while keeping the curvature of the cable 1 and sheath tube 2 within a predetermined range.

In the cable protection conduit member 250 of this embodiment, the minimum diameter expansion angle of the first enlarged diameter portion 51 or the second enlarged diameter portion 52 of the socket 42 and the first enlarged diameter portion 51 or the second enlarged diameter portion of the socket 41 are The sum with the minimum diameter expansion angle of the diameter portion 52 is 24° or less.
According to the above configuration, the tube axis J5 of the cable protection conduit member 250-2 can be tilted and rotated up to 24° with respect to the tube axis J5 of the cable protection conduit member 250-1. As a result, the cable protection conduit 4 made up of the cable protection conduit member 250 can be bent appropriately.

In the cable protection conduit member of the present embodiment, a stopper portion 58 is provided at the end of at least one of the sockets 41 and 42 on the main pipe 31 side. protrudes to

According to the above configuration, the ends 6 and 7 inserted into at least one of the sockets 41 and 42 abut against the stopper portion 58, thereby stabilizing the position of the cable protection tube 5 on the tube axis J31. This creates a distance between the end 125 of the cable protection tube 5 and the main tube 31, resulting in an extra margin for insertion. When a force acts on the cable protection pipe member 250 in the pipe axis direction A, the stopper portion 58 is deformed. For example, when a large force acts on the cable protection tube 5 as in the case of an earthquake, the stopper portion 58 is elastically deformed and protrudes outward in the radial direction B as illustrated in FIGS. 4 and 6 . Therefore, the cable protection tube 5 can be moved within the margin of insertion, and the force acting on the cable protection conduit member 250 can be dispersed appropriately.

Further, the cable protection conduit 4 of the present embodiment includes a plurality of cable protection conduit members 250 described above, and the cable protection conduit up to the protection tube insertion position 260 of the socket 41 of the joint 21 of the cable protection conduit member 250-1. The end 6 of the cable protection tube 5 of the path member 250-2 is inserted.

According to the above-described configuration, after inserting the sheath tube 2 into the cable protection conduit member 250-1, the cable protection tube 5 of the cable protection conduit member 250-2 is kept small while the curvature of the sheath tube 2 is kept small. can be easily inserted straight into the receptacle 41 of the cable protection conduit member 250-2 without requiring a highly skilled operator or special tools. In addition, the cable protection tube 5 and the joint 21 are rotated around the socket fulcrum 102, and the curvature of the sheath tube 2 is kept within a predetermined range, and the cable is protected according to the existing buried objects, the position of the road, etc. The shape of the pipeline 4 can be easily changed.

In the cable protection conduit of this embodiment, the distance between the socket fulcrum portion 102 of the socket 41 and the socket support portion 102 of the socket 42 in the tube axis direction A is 400 mm or more and 600 mm or less. Further, the effective length M when the tube axes J5 and J31 of the cable protection conduit member 250 are aligned is 600 mm or more and 5600 mm or less.
For example, when the sum of the minimum diameter expansion angle of the first enlarged diameter portion 51 or the second enlarged diameter portion 52 of the sockets 41 and 42 is 24° or less as described above, the effective lengths M and N are 1000 mm. or 2000 mm.

According to the above configuration, the curvature of the sheath tube 2 is maintained within a predetermined range, the length of the cable protection tube 5 is set to, for example, about 5000 mm or 10000 mm for ease of handling, and the cable protection tube 4 is defined by the communication cable. It can be freely bent within the specified minimum radius of curvature of 5m or 10m. This reliably prevents the sheath tube 2 from being bent with an excessive curvature and prevents the sheath tube 2 from being damaged.
For example, if the maximum bending angle is 24°, the effective length M can be 1 m to achieve a minimum radius of curvature of 5 m, and the effective length M can be 2 m to achieve a minimum radius of curvature of 10 m. be able to.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the scope of the claims. Transformation and change are possible.

4 Cable protection conduit 5 Cable protection tubes 6, 7 End 21 Joint 102 Socket fulcrum 250, 250-1, 250-2 Cable protection conduit member J5 Tube shaft (protection tube shaft)
J31 pipe shaft (main pipe shaft)
M effective length

Claims (6)

comprising a linear cable protection tube and a joint connected to the cable protection tube,
The joint comprises a main pipe, a first receptacle provided at one end of the main pipe, and a second receptacle provided at the other end of the main pipe,
The first socket and the second socket are composed of a socket fulcrum portion provided at an intermediate position in the main pipe axial direction along the main pipe axis of the main pipe, and a socket fulcrum portion extending from the socket fulcrum portion to the main pipe shaft. A first enlarged diameter portion whose diameter increases toward the main pipe along the direction, and a second enlarged diameter portion whose diameter increases from the socket fulcrum portion along the axial direction of the main pipe as it moves away from the main pipe. and
In a state in which the main tube shaft and the protection tube axis of the cable protection tube are aligned in a straight line, from the end of the cable protection tube opposite to the end fitted to the joint, the cable is inserted into the second socket. When another cable protection tube having the same outer diameter as the cable protection tube is inserted, the effective length to the position where the tip of the another cable protection tube can reach is 600 mm or more and 5600 mm or less. A cable protection conduit member characterized by: In the first socket, of the diameter expansion angle of the first diameter expansion portion with respect to the main pipe axis and the diameter expansion angle of the second diameter expansion portion with respect to the main pipe axis, the smaller diameter expansion angle is 1 diameter expansion angle, and in the second socket, the smaller of the diameter expansion angle of the first diameter expansion portion with respect to the main pipe axis and the diameter expansion angle of the second diameter expansion portion with respect to the main pipe axis When the diameter expansion angle is the second diameter expansion angle,
The sum of the first diameter expansion angle and the second diameter expansion angle is 24° or less.
The cable protection conduit member according to claim 1. At least one of the first socket and the second socket is provided with a stopper part that has flexibility and protrudes inward in the radial direction.
The cable protection conduit member according to claim 1 or 2. A plurality of cable protection conduit members according to any one of claims 1 to 3,
A cable protection conduit, wherein the joint of one cable protection conduit member is connected to the cable protection tube of another cable protection conduit member. In each of the plurality of joints, the distance between the socket fulcrum portion of the first socket and the socket support portion of the second socket in the main pipe axial direction is 200 mm or more and 600 mm or less.
5. The cable protection conduit according to claim 4. the effective length is 1000 mm or 2000 mm;
Cable protection conduit according to claim 5.

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