JP2012125023A - Cable lying tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cable lying tool which sufficiently reduces friction with the cable even if a pipeline is bent in all directions and is attached to existing pipeline members.SOLUTION: A cable lying tool includes: a holding part 21 attached to an inner surface 2a of a pipeline member 1 for laying power cables 50 underground and extending at least over the whole circumference of the inner surface 2a of the pipeline member 1; and multiple balls 22 rotatably held by the holding part 21 and contacting with the power cables 50 pulled into the holding part 21.

Description

  The present invention relates to a cable laying tool that is used by being attached to a pipe member for laying a power cable or a communication cable in the ground, and particularly reduces the tension acting on the cable when the cable is drawn into the pipe member. The present invention relates to a cable laying tool that can be used.

  The underground power transmission line pipeline is configured by connecting a number of pipeline members having a predetermined length in series. To lay the power cable, after passing the rope through the pipeline, connect the end of the power cable to the rope on the inlet side of the pipeline, and wind the rope with a winch or the like placed on the outlet side of the pipeline Is going by. When the cable is drawn into the pipe, there is a problem that a large frictional resistance is generated by the contact between the pipe inner surface and the cable, and the pulling tension of the cable is increased. Therefore, in the conventional underground power transmission line, it is difficult to form a long pipe line, and it is necessary to shorten the cable drawing section by installing many manholes for cable connection.

  Conventionally, a cable protection tube for reducing friction between a pipe line and a cable is known (see, for example, Patent Document 1). In this cable protection tube, a medium-throttle cylindrical roller is rotatably disposed inside the inner periphery of a pipeline that is curved in an arc shape.

Japanese Patent Laid-Open No. 11-299034

  However, the cable protection tube of Patent Document 1 has a problem that it is difficult to sufficiently reduce the friction with the cable because the roller is disposed only inside the tube body curved in an arc shape. That is, since the pipe line in which the cable is laid may be bent not only in the horizontal direction but also in the vertical direction at the same time, when the pipe is bent in the vertical direction, the cable protection pipe of Patent Document 1 There is a problem that the cable is detached from the roller and friction with the cable is increased. Further, the cable protection tube of Patent Document 1 has a special cross section, and is difficult to attach to an existing cylindrical pipe line. Therefore, it is desired to develop a cable laying tool that can sufficiently reduce the friction with the cable even if the pipe is curved in any direction and that can be applied to existing pipe members.

  Accordingly, an object of the present invention is to provide a cable laying tool that can sufficiently reduce friction with a cable even when the pipe is curved in any direction and can be attached to an existing pipe member. And

  In order to achieve the above object, the invention according to claim 1 is attached to the inner surface of a pipe member for laying a cable in the ground, and extends at least over the entire circumference in the circumferential direction of the inner surface of the pipe member. And a plurality of rotating members that are rotatably held by the holding portion and that can come into contact with the cable drawn inside the holding portion.

  According to the present invention, when the cable is drawn into the duct member, the plurality of rotating members that come into contact with the cable rotate, so that the contact resistance between the cable and the rotating member is reduced, and the tension acting on the cable is reduced. It becomes possible.

  According to a second aspect of the present invention, in the cable laying tool according to the first aspect, the holding portion is divided in the axial direction of the pipe line member, and each of the divided holding portions is a flexible flexible member. It is characterized by being connected in an axial direction via a portion.

  According to a third aspect of the present invention, in the cable laying tool according to the first or second aspect, the rotating member is made of a metal or resin ball.

  According to the first aspect of the present invention, since the holding portion that holds the rotating member extends over the entire circumference of the inner surface of the pipe member, even when the pipe member is curved in all directions, It becomes possible to make a cable and a rotation member contact reliably. Therefore, even when the pipeline on which the cable is laid is curved in all directions, the tension acting on the cable can be reduced when the cable is drawn into the pipeline. Thereby, it is possible to form a long pipeline for laying the cable, and the number of manholes for connecting cables can be reduced. In addition, since the holding portion that holds the rotating member extends over the entire circumference in the circumferential direction of the inner surface of the pipe member, the mounting of the holding portion to the pipe member is less restricted, and the cable laying tool is already installed. It can also be attached to other pipe lines.

  According to the second aspect of the present invention, the holding portion is divided in the axial direction of the pipe member, and the divided holding portions are connected in the axial direction via flexible portions, so Even when the pipe member is curved, it is easy to attach the holding portion to the pipe member.

  According to the third aspect of the present invention, since the rotating member is composed of a metal or resin ball, the ball rotates following the movement in any direction of the cable. The frictional resistance can be further reduced.

It is a perspective view which shows the attachment state to the pipe line member of the cable laying tool concerning Embodiment 1 of this invention. It is an expanded sectional view of the cable laying tool of FIG. It is an expanded sectional view which shows the modification of the holding | maintenance part of the cable laying tool of FIG. It is a side view which shows the structure of the pipe line to which the cable laying tool of FIG. 1 is applied. It is sectional drawing of the pipe line member which comprises the pipe line of FIG. It is sectional drawing which shows the detail of the edge part of the cable-laying tool of FIG. It is a schematic diagram which shows the cable-laying operation | work using the cable-laying tool of FIG. It is a perspective view which shows the attachment state to the pipe line member of the cable laying tool concerning Embodiment 2 of this invention. It is a side view of the cable laying tool of FIG. It is a side view which shows the structure of the pipe line to which the cable laying tool of FIG. 8 is applied. It is sectional drawing of the pipe line member which comprises the pipe line of FIG. It is process drawing which shows the modification of the cable laying tool of FIG. 1, (a) is a development view of a cable laying tool, (b) is a development view which shows the state which cut | disconnected the cable laying tool in the predetermined | prescribed magnitude | size. (C) is a perspective view showing a state in which the cable laying tool is formed in a cylindrical shape.

  Next, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
1 to 7 show Embodiment 1 of the present invention. As shown in FIGS. 1 and 4, a pipe K1 for laying a power cable 50 as a cable in the ground is configured by connecting a number of straight pipes 1 as pipe members in series. As shown in FIG. 5, the straight pipe 1 includes a straight pipe main body 2, a connection portion 3, a fixing means 4, and a seal portion 5. The straight pipe body 2 extends along a linear axis P1. The connection part 3 is provided in the one end part 2a of the straight pipe | tube main body 2 formed in the cylindrical shape. The connecting portion 3 is formed to have a diameter larger than that of the tube main body 2, and about half of the inner surface in the axial direction is fixed to the outer peripheral surface of the straight tube main body 2 via fixing means 4 such as a bonding agent. A seal portion 5 is formed on a portion of the inner surface of the connection portion 3 adjacent to the fixing means 4. The seal part 5 can be fitted to the other end 2b of the straight pipe body 2 of the adjacent straight pipe 1. In a state where the seal portion 5 and the other end portion 2b of the straight pipe main body 2 are fitted, intrusion of liquid such as water contained in the ground into the pipe main body 2 is prevented. On the surface of the straight pipe main body 2, a display line 2 d for displaying a fitting amount with the seal portion 5 of the adjacent straight pipe main body 2 is provided.

  The length of the straight pipe 1 in the axial direction differs depending on the size of the diameter of the straight pipe 1. For example, the axial length of the small-diameter straight pipe 1 is set to 1 m, and the axial length of the large-diameter straight pipe 1 is set to 2 m. As shown in FIG. 4, the total length of the pipe line K1 is set to L1. One end in the axial direction of the pipe line K1 is opened in a manhole (not shown) for connecting the power cables 50 to each other. Similarly, the other end in the axial direction of the pipe line K1 opens into another manhole (not shown). The straight pipe 1 is made of a material such as FRP (fiber reinforced plastic), steel, concrete or the like depending on the application.

  As shown in FIGS. 1 and 2, a cable laying tool 20 is attached to the inner surface 2 c of the straight pipe body 2. The cable laying tool 20 includes a holding portion 21 and a ball 22 as a rotating member. The holding part 21 is formed in a cylindrical shape, and the length in the axial direction is the same as that of the straight pipe body 2. The inner peripheral surface 21a of the holding part 21 is formed smoothly. Fixing protrusions 21c are intermittently formed in the circumferential direction on the outer peripheral surface 21b of the holding portion 21. The fixed protrusion 21 c extends in the axial direction of the holding portion 21. The fixing protrusion 21 c has a function of fixing the holding portion 21 to the inner peripheral surface 2 c of the straight pipe main body 2 by contact with the inner peripheral surface 2 c of the straight pipe main body 2.

  The holding portion 21 is formed with a plurality of holding holes 21d for holding the ball 22 rotatably. The holding holes 21d are formed at predetermined intervals in the axial direction and the circumferential direction of the holding portion 21. The diameter of the holding hole 21 d is slightly larger than the outer diameter of the ball 22. The holding hole 21d penetrates the inner peripheral surface 21a and the outer peripheral surface 21b of the holding portion 21. Protrusions 21e and 21f that prevent the ball 22 held in the holding hole 21 from being detached from the holding hole 21 are formed on the periphery of the holding hole 21d of the holding part 12. The protruding portion 21e is located on the outer peripheral surface 21b side of the holding portion 21, and is formed by caulking (caulking), for example. Similarly, the protruding portion 21f is located on the inner peripheral surface 21a side of the holding portion 21, and is formed by caulking, for example.

  Part of the ball 22 held in the holding hole 21d is exposed on the inner peripheral surface 21a side and the outer peripheral surface 21b side of the holding portion 21. In the first embodiment, the holding projection 21c is provided on the holding portion 21, so that the holding portion 21 is fixed to the inner peripheral surface 2c side of the tube body 2 via the fixing projection 21c. The held ball 22 is rotatable in all directions. A portion of the ball 22 located on the inner peripheral surface 21 a side of the holding portion 21 can come into contact with the power cable 50 drawn inside the holding portion 21. The ball 22 is made of metal or resin. For example, in the straight pipe 1 in which the diameter of the holding portion 21 is large, a ball 22 using a resin such as silicon is used for weight reduction. In the straight pipe 1 in which the diameter of the holding portion 21 is small, the ball 22 is made of a metal having high corrosion resistance such as stainless steel.

  FIG. 3 shows a modification of FIG. In FIG. 2, the holding unit 21 is composed of one member, but in FIG. 3, the holding unit 21 is composed of an inner holding unit 211 and an outer holding unit 212. Both the inner holding part 211 and the outer holding part 212 are formed in a cylindrical shape. A holding hole 21d for holding the ball 22 is formed in the inner holding portion 211 and the outer holding portion 212, as in FIG. The inner holding portion 211 is formed with a protruding portion 21f that prevents the ball 22 from being detached from the holding hole 21d. The outer holding portion 212 is formed with a protruding portion 21e that prevents the ball 22 from being detached from the holding hole 21d.

  The holding part 21 of FIG. 3 is manufactured by the following processes, for example. First, a rod-shaped magnet (not shown) is arranged inside the inner holding portion 211, and in this state, a ball 22 made of stainless steel is fitted into each holding hole 21f of the inner holding portion 211. In this state, the ball 22 is held in each holding hole 211 of the inner holding portion 211 by the attractive force of the magnet. Next, the outer holding portion 212 is fitted on the outer side of the inner holding portion 211, the outer holding portion 212 is pushed in the axial direction, and the ball 22 is displaced inward in the radial direction. Then, when the ball 22 is held by both the inner holding portion 211 and the outer holding portion 212, the pushing of the outer holding portion 212 is finished. As described above, when the holding portion 21 has the structure shown in FIG. 3, the ball 22 can be held without caulking (caulking) the periphery of the holding hole 21d, compared with the holding portion 21 shown in FIG. Thus, the work for holding the ball 22 is facilitated.

  FIG. 6 shows details of the axial end of the holding portion 21. In the first embodiment, a fixing projection 21c is formed on the outer peripheral surface 21b side of the holding portion 21, and the holding portion 21 is brought into contact with the inner peripheral surface 2c of the tube main body 2 by contacting the fixing projection 21c with the inner peripheral surface 2c. Although it fixes to the surrounding surface 2c, by forming the engaging part 21g which bulges radially outward at the axial direction end part of the holding | maintenance part 21, external force F accompanying drawing of the power cable 50 is made. On the other hand, it is possible to reliably prevent the holding portion 21 from shifting in the axial direction.

  Next, the procedure and operation of laying work of the power cable 50 in the first embodiment will be described.

  As shown in FIG. 4, a conduit K1 for laying the power cable 50 is buried in the ground. In the first embodiment, the number of power cables 50 laid on the pipe line K1 is three, but the number of power cables 50 laid may be one or four or more. The pipe line K1 is composed of a plurality of straight pipes 1 connected in series as described above, and the total length is L1. A cable laying tool 20 is attached in advance to the inner surface 2c of the straight pipe body 2 of each straight pipe 1 in the pipe line K1. That is, when the conduit K1 is buried in the ground, the cable laying tool 20 is attached in advance to the inner surface 2c of the existing straight pipe 1. When laying the power cable 50, first, the rope 61 is passed through the pipeline K1, and the rope 61 is in a state of protruding outward from both ends of the pipeline K1. One of the ropes 61 passed through the pipe line K1 is connected to the tip of the power cable 50 to be laid, and the other is connected to the drum of the winch 60 as shown in FIG.

  Next, by starting the winch 60, the other end of the rope 61 is wound up by the electric winch 60, and the power cable 50 is drawn into the pipe line K1. FIG. 1 shows a state where the power cable 50 is drawn into the pipe line K1. In this state, the cable laying tool 20 attached to the inside of the straight pipe body 2 of each straight pipe 1 of the pipe line K1 and the power cable 50 come into contact. Since the cable laying tool 20 has a plurality of freely rotatable balls 22, when the power cable 50 is drawn into the conduit K <b> 1, the plurality of balls 22 that are in contact with the power cable 50 move the power cable 50. Since it rotates in the direction, the contact resistance between the power cable 50 and the ball 22 is reduced, and the tension acting on the power cable 50 can be reduced.

  FIG. 7 shows a state in which the power cable 50 that has moved in the pipeline K1 by the rope 61 has come out of the other side of the pipeline K1. In this state, the rotation of the drum of the winch 60 is stopped, and the tip end portion of the power cable 50 is located in a manhole (not shown). When the installation of the power cable 50 to the pipeline K1 is completed, the power cable 50 is cut to a predetermined length, and then the power cables 50 exposed from the pipeline K1 are connected in a manhole (not shown). .

  As described above, the holding portion 21 that holds the ball 22 extends over the entire circumference of the inner surface 2a of the straight pipe body 2 in the straight pipe 1 so that the power cable 50 and the ball 22 can be reliably brought into contact with each other. It becomes possible. Therefore, the tension acting on the power cable 50 can be reduced when the power cable 50 is pulled into the pipe K1. Thereby, it is possible to form a long pipe line K1 for laying the power cable 50, and the number of manholes for cable connection can be reduced. In addition, since the holding portion 21 that holds the ball 22 extends over the entire circumference in the circumferential direction of the inner surface 2a of the straight pipe 1, the mounting of the holding portion 21 to the straight pipe 1 is less restricted, and the cable is laid. The tool 20 can be attached to an existing pipe line.

(Embodiment 2)
8 to 11 show Embodiment 2 of the present invention. The difference between the second embodiment and the first embodiment is only the presence or absence of the flexible portion 23, and the other portions are in accordance with the first embodiment. Therefore, the same reference numerals as those in the first embodiment are given to the conforming portions. Therefore, the description of the conforming part is omitted.

  As shown in FIGS. 8 and 10, the pipe K2 for laying the power cable 50 in the ground is configured by connecting a large number of straight pipes 1 and curved pipes 11 as pipe members in series. . As shown in FIG. 11, the bent tube 11 includes a bent tube main body 12, a connection portion 3, a fixing means 4, and a seal portion 5. The curved pipe body 12 extends along the curved axis P2. The radius of curvature R of the curved pipe 11 varies depending on the application. In the pipe line K2, it is possible to connect the curved pipes 11 having different curvature radii R, and the degree of freedom of the laying route of the power cable 50 is increased.

  As shown in FIG. 11, the seal portion 5 can be fitted to the other end portion 12 b of the bent tube body 12 of the adjacent bent tube 11. In a state where the seal portion 5 and the other end portion 12b of the bent tube main body 12 are fitted, infiltration of liquid such as water contained in the ground into the bent tube main body 12 is prevented. On the surface of the curved pipe main body 12, a display line 12d for displaying a fitting amount with the seal portion 5 of the adjacent curved pipe main body 12 is provided.

  The length of the bent tube 11 in the axial direction varies depending on the diameter of the bent tube 11. For example, the axial length of the small-diameter curved tube 11 is set to 1 m, and the axial length of the large-diameter curved tube 11 is set to 2 m. As shown in FIG. 10, the total length of the pipe line K2 is set to L2. One end in the axial direction of the pipe line K2 is opened in a manhole (not shown) for connecting the power cables 50 to each other. Similarly, the other end in the axial direction of the pipe line K2 is opened in another manhole (not shown).

  As shown in FIGS. 8 and 9, a cable laying tool 20 is attached to the inner surface 12 c of the curved pipe body 12. In this Embodiment 2, the holding part 21 of the cable laying tool 20 is divided | segmented into the axial direction of the curved pipe 11, and each divided | segmented holding | maintenance part 21 is made into an axial direction via a flexible part which can be bent. It is connected. The flexible portion 23 can be bent in the vertical direction and the horizontal direction along the inner surface shape of the pipe line K2, and is made of, for example, a bellows-like metal or resin. The holding unit 21 holds a plurality of balls 22 at a predetermined interval in the circumferential direction. In the second embodiment, only one row of balls 22 is arranged in the circumferential direction in the holding portion 21, but the arrangement of the balls 22 may be a plurality of rows.

  In the second embodiment configured as described above, the holding portion 21 is divided in the axial direction of the bent tube 11, and the divided holding portions 21 are connected in the axial direction via flexible portions that can be bent. Therefore, even if the curvature radius R of the curved pipe 11 is small, the holding portion 21 can be easily attached along the inner surface shape of the curved pipe 11, and the cable laying tool 20 can be attached to the curved pipe 11. It becomes easy. Moreover, since the holding | maintenance part 21 holding the ball | bowl 22 is extended over the circumferential direction perimeter in the inner surface 12c of the curved pipe main body 12 of the curved pipe 11, even when the curved pipe 11 is curving in all directions, it is a power cable. 50 and the ball 22 can be reliably brought into contact with each other. Therefore, even when the pipeline K2 where the power cable 50 is laid is curved in all directions, the tension acting on the power cable 50 can be reduced when the power cable 50 is pulled into the pipeline K2. it can.

  The embodiment of the present invention has been described in detail above, but the specific configuration is not limited to the above-described embodiment, and even if there is a design change or the like without departing from the gist of the present invention, It is included in this invention. For example, in the first and second embodiments, the cable laying tool 20 is configured to use the holding portion 21 that is formed into a cylindrical shape. However, as shown in FIG. As shown in FIG. 12B, the sheet-like holding portion 21 having the length W1 held in the section is cut into a length W2 corresponding to the inner diameter of the conduit K1, and then shown in FIG. 12C. Thus, it is good also as a structure which makes the cable laying tool 20 which joins the both ends of the holding | maintenance part 21 in the junction part A, and makes it the outer diameter D.

  In the first embodiment, the cable laying tool 20 is attached to all the straight pipes 1. However, when the tension acting on the power cable 50 is significantly smaller than the allowable value, all the straight pipes are used. It is not necessary to attach the cable laying tool 20 to 1, and the number of cable laying tools 20 used can be reduced. Furthermore, the rotating member is not limited to the ball 22, and any structure can be used as long as it can reduce the frictional resistance when contacting the power cable 50 such as a roller or a rotating belt.

  In the first and second embodiments, the laying of the power cable 50 has been described. However, the cable laid in the pipeline K1 or the pipeline K2 is not limited to the power cable 50, and is a communication cable. Alternatively, a control cable or the like may be used. Moreover, in Embodiment 1, 2, although the example which retrofits the cable laying tool 20 to the existing straight pipe 1 or the curved pipe 11 was demonstrated, the cable laying tool 20 is the straight pipe 1 newly manufactured, In the manufacturing process of the curved pipe 11, it is good also as a structure attached to the straight pipe 1 or the curved pipe 11.

1 Straight pipe (pipe line member)
11 Curved pipe (pipe line member)
20 Cable laying tool 21 Holding part 22 Ball (rotating member)
23 flexible part 50 power cable (cable)
60 winch 61 rope K1 pipeline K2 pipeline

Claims (3)

A holding portion that is attached to the inner surface of the pipe member for laying the cable in the ground, and extends at least over the entire circumference in the circumferential direction of the inner surface of the pipe member;
A plurality of rotating members that are rotatably held by the holding portion and that can come into contact with the cable drawn into the holding portion;
A cable laying tool characterized by comprising:   The said holding | maintenance part is divided | segmented into the axial direction of the said pipeline member, Each divided | segmented holding | maintenance part is connected to the axial direction via the flexible part which can be bent. The cable laying tool described.   The cable laying tool according to claim 1 or 2, wherein the rotating member is made of a metal or resin ball.

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