Cable extraction device

Abstract

To provide a cable extraction device capable of simultaneously extracting all three cables including a three-phase cable out of a conduit and delivering them outside a manhole, thereby significantly reducing the time required for removal work and improving work efficiency.SOLUTION: A cable extraction device 400 is configured to simultaneously pull out and convey toward the ground three cables 102 of a three-phase cable 100 protruding from a conduit 20 on a wall surface 32 of a manhole 30. The cable extraction device 400 includes a trolley 410 traveling within the manhole 30, a reaction support (reaction support portion 430b, rear body 440) inserted at the center of the three cables 102 protruding from the conduit 20, a gripping clamp 450 urging each of the three cables 102 toward the reaction support, and a traveling cylinder 460 that pushes the wall surface 32 of the manhole 30 on the conduit 20 side to travel the trolley 410.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a cable pulling device that pulls out three cables of a three-phase cable protruding from a conduit in the wall of a manhole and sends them out toward the ground. [Background technology]

[0002] In recent years, underground cabling has become increasingly common in cities due to considerations of aesthetics and safety. In underground cabling, troughs and conduits are buried underground, and power cables, communication cables, etc. (hereinafter referred to as underground cables) are laid inside them. Underground cables are removed when they deteriorate over time or are no longer needed.

[0003] As a method for removing an underground cable, for example, Patent Document 1 discloses a "method for removing an underground ultra-high voltage power transmission cable that has been laid for a long time in an underground conduit connecting two manholes." The underground ultra-high voltage power transmission cable removal method in Patent Document 1 includes "a step of providing a temporary hook in the earthen floor of a manhole that has the terminal end of one of the two ends of the power transmission cable that needs to be removed, both ends of which have been cut in advance, a step of connecting a hydraulic jack to the temporary hook, a step of connecting the terminal end of the power transmission cable to the hydraulic jack, and a step of driving the hydraulic jack and using its pulling force to pull the power transmission cable from the conduit into the manhole against lateral pressure and its own weight pressure." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7177537 Summary of the Invention [Problem to be solved by the invention]

[0005] When removing an underground cable from a manhole, the joints connecting the cables are first disassembled and removed inside the manhole. In Patent Document 1, a pulling eye is attached to the end of the three-phase cable that has been cut off from the joints, and the pulling eye is then pulled by a pulling machine such as a hydraulic jack to pull the underground cable out of the conduit.

[0006] When the power transmission system is a three-phase, three-wire system, three underground cables are buried underground as one circuit. In Patent Document 1, hydraulic jacks are used to pull out the power transmission cables one by one, but this method takes a long time to wind up all three cables. This results in low work efficiency and prolonged line outages.

[0007] In view of these problems, the present invention aims to provide a cable extraction device that can extract the three cables that make up a three-phase cable from a conduit together and send them out of a manhole, thereby significantly reducing the time required for removal work and improving work efficiency. [Means for solving the problem]

[0008] In order to solve the above problems, a typical configuration of the cable pulling device of the present invention is a cable pulling device that pulls out three cables of a three-phase cable protruding from a conduit in the wall of a manhole together and sends them out toward the ground, and is characterized by comprising a cart that runs inside the manhole, a reaction force receiver inserted into the center of the three cables protruding from the conduit, a holding clamp that urges each of the three cables toward the reaction force receiver, and a traveling cylinder that pushes the wall surface of the manhole on the conduit side to move the cart. [Effects of the Invention]

[0009] According to the present invention, a cable extraction device can be provided that can pull out the three cables that make up a three-phase cable from a conduit together and send them out of a manhole, thereby significantly reducing the time required for removal work and improving work efficiency. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a work site where a three-phase cable is removed. [Figure 2] FIG. 1 is a diagram illustrating a three-phase cable. [Figure 3] 1 is a diagram illustrating a cable pulling device according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram illustrating the details of the extraction device. [Figure 5] FIG. 10 is a diagram illustrating the rear main body as viewed from behind. [Figure 6] FIG. 10 is a diagram illustrating pre-processing for the extraction work. [Figure 7] FIG. 10 is a diagram illustrating the initial withdrawal (first time). [Figure 8] FIG. 10 is a diagram illustrating the initial withdrawal (second time). [Figure 9] 5A to 5C are diagrams illustrating the operation of the extraction device of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0012] Fig. 1 is a diagram illustrating a work site 10 where a three-phase cable 100 is to be removed. As shown in Fig. 1, at the work site, conduits 20 are buried under a road surface 12, and manholes 30 for maintenance work are provided at predetermined intervals between the conduits 20.

[0013] 2A and 2B are diagrams illustrating a three-phase cable 100, with Fig. 2A being a cross-sectional view and Fig. 2B being a perspective view of one cable 102. As shown in Figs. 1 and 2, a three-phase cable 100 (for example, a POF cable (Pipe-type Oil Filled cable)) is laid inside a conduit 20. In the case of a POF cable, insulating oil (not shown) is filled inside the conduit 20 and pressurized.

[0014] Although the term "conduit" is usually used to refer to a pipe that houses a cable, in the case of a POF cable, the steel pipe or the like in the outermost layer of the cable can be considered to play a role similar to that of a conduit. Therefore, in this embodiment, the conduit 20 includes the steel pipe or the like in a POF cable.

[0015] As shown in Fig. 2(a), a three-phase cable 100 is configured to include three cables 102. As shown in Fig. 2(b), the outer periphery of each conductor 106 (segmented conductor) is covered with a sheath 108, and a skid wire 104 is wound around the outer periphery of the sheath 108.

[0016] When removing the three-phase cable 100, first, the connection parts (not shown) connecting the three-phase cable 100 to the multiple conduits 20 connected to the manhole 30 are cut off and disassembled. Then, the end of the three-phase cable 100 cut off from the connection parts is pulled by the cable pulling device 400 of this embodiment (see FIG. 1), thereby pulling the three-phase cable 100 from the conduits 20.

[0017] Fig. 3 is a diagram illustrating a cable pulling-out device according to this embodiment. The cable pulling-out device of this embodiment (hereinafter referred to as pulling-out device 400) pulls out three cables (see Fig. 2) of a three-phase cable 100 protruding from the conduit 20 in the wall surface 32 of a manhole 30 together and sends them out toward the ground. As shown in Fig. 3, rails 40 are laid on the bottom 34 of the manhole 30, and the pulling-out device 400 is movable on the rails 40 in a direction toward and away from the wall surface 32 of the manhole 30.

[0018] The extraction device 400 of this embodiment is configured to include a carriage 410, a main body 420, gripping clamps (front clamp 452, rear clamp 454), and a traveling cylinder 460. The carriage 410 has wheels 412 attached to its bottom, and travels on rails 40 inside the manhole 30. The main body 420 is placed on top of the carriage 410.

[0019] Figure 4 is a diagram illustrating the details of the extraction device 400. Figure 4(a) is an enlarged view of the carriage 410 and main body 420 in Figure 3. Figure 4(b) is a two-sided view of the rear main body 440. Figure 4(c) is a two-sided view of the front main body 430.

[0020] As shown in Figures 3 and 4(a), the main body 420 is composed of a front main body 430 and a rear main body 440, which are divided into front and rear parts in the movement direction of the extraction device 400. This allows the weight per body to be lighter than when the main body is not divided. This therefore makes it possible to smoothly carry the device into and out of the manhole 30. However, this is not limiting, and the main body 420 may be configured as one body rather than being divided into two parts.

[0021] 4(b), the rear body 440 is a substantially Y-shaped member that is inserted into the center (between the cables 102) of the three cables 102 protruding from the conduit 20, and functions as a reaction force receiver. In detail, the rear body 440 has three fan-shaped ribs 442 that are equally spaced in the circumferential direction, and three grooves 444 into which the cables 102 are inserted are formed between the three ribs 442.

[0022] Rear clamps 454, which are clamps for gripping from three directions, are attached to the rear body 440 for the three grooves 444, respectively.

[0023] 4(c), the front main body 430 has a cable holding portion 430a arranged on the side close to the conduit 20, and a reaction force receiving portion 430b arranged on the side adjacent to the rear main body 440. The reaction force receiving portion 430b of the front main body 430 has three fan-shaped ribs 432 arranged at equal intervals in the circumferential direction, and three grooves 434 into which the cable 102 is inserted are formed between the three ribs 432. The cable holding portion 430a is cylindrical, and has an insertion hole 436 formed therein through which the cable 102 is inserted.

[0024] Front clamps 452, which are clamps for gripping the reaction force receiving portion 430b of the front main body 430, are attached to the three grooves 434 from three directions.

[0025] 5 is a diagram illustrating the rear main body 440 as viewed from the rear. When the gripping cylinder 456 connected to the gripping clamps (front clamp 452 and rear clamp 454) is driven, the rear clamp 454 moves toward the groove 444 as shown in FIG. 5. As a result, the cable 102 inserted into the groove 444 is urged (pressed) from three directions toward the rear main body 440 by the rear clamp 454. In the front main body 430, the cable 102 is urged by the front clamp 452 toward the groove 434 of the reaction force receiving portion 430b, which receives the reaction force.

[0026] 3, the extraction device 400 of this embodiment is provided with a traveling cylinder 460 that pushes the wall surface 32 of the manhole 30 on the pipeline 20 side to allow the carriage 410 to travel. In this embodiment, a total of three traveling cylinders 460 are provided: two (one not shown) on the upper part of the main body 420 and one on the lower part of the main body 420.

[0027] A front end 462 of the traveling cylinder 460 (the end on the right side in the drawing, close to the wall surface 32) is connected to the manhole-side plate 472 via a connecting rod 490. Strictly speaking, the front end 462 of the traveling cylinder 460 is the tip of a piston (described later) housed inside the traveling cylinder 460.

[0028] The manhole-side plate 472 is connected to a load cell-side plate 474 attached to the wall surface 32 of the manhole 30. The rear end 464 of the traveling cylinder (the end on the left side in the drawing, away from the wall surface 32) is connected to an end plate 482. A wheel 482a that travels on the rail 40 is provided on the lower part of the end plate 482.

[0029] Fig. 6 is a diagram illustrating pre-processing for the extraction work. Fig. 6(a) illustrates the state before the extraction device 400 is placed in the manhole 30 of Fig. 1. The state is shown in which the connectors (not shown) connecting the cables have been cut, and the cable ends protrude from the side of the manhole. Furthermore, the cut conduit 20 protrudes from the wall surface 32, and the conductor 106 of the cable 102 is exposed from the conduit 20. In addition, rails 40 for the extraction device 400 to travel on are laid on the bottom 34 of the manhole 30.

[0030] Depending on the installation conditions within the manhole 30, when the connection portion (not shown) is cut, the length of the cable 102 protruding from the wall surface 32 may be short, as shown in FIG. 6(a), and the cable 102 may not be able to be grasped by the pulling device 400 in this state. For example, in the case of a POF cable, since no offset is required during installation, the size of the connection portion relative to the manhole size is larger than that of other cables. Therefore, after the connection portion is cut, the excess length of the cable within the manhole is likely to be short. In this case, during the initial pulling, the cable 102 can be engaged with the pulling device 400 using a pulling rod 140 or the like and pulled.

[0031] Figure 6(b) is a diagram illustrating the parts used for the pre-processing and initial extraction of the extraction work. For the pre-processing of the extraction work, the sleeve 120, connecting screw shaft 130, extraction rod 140, fixing plate 150, and nut 160 shown in Figure 6(b) are used. The connecting screw shaft 130 is a shortened version of the extraction rod 140.

[0032] The end of the sleeve 120 is an I-bolt 124. The connecting screw shaft 130 has a screw 134 at its end, and the pull rod 140 also has a screw 144 at its end. The connecting screw shaft 130 and the pull rod 140 are also internally threaded at the ends opposite the screws 134 and 144. The fixing plate 150 has a hole 152 through which the screw 144 can be inserted, and is used in combination with a nut 160.

[0033] Fig. 6(c) is a diagram illustrating a state in which pre-processing for the pulling operation has been performed inside the manhole 30 of Fig. 6(a). In the pre-processing for the pulling operation, the conductor 106 of the cable 102 is inserted into the inside of the sleeve 120 as shown in Fig. 6(c). Then, the sleeve 120 is crimped onto the conductor 106 of the cable 102.

[0034] 7A and 7B are diagrams illustrating the initial withdrawal (first time). First, as shown in Fig. 7A, the connecting screw shaft 130 is attached to the I-bolt 124 of the sleeve 120. Then, the extraction rod 140 is attached to the screw 134 of the connecting screw shaft 130. This connects the connecting screw shaft 130 and the extraction rod 140 to the sleeve 120.

[0035] Next, as shown in FIG. 7(b), the screw 144 of the extraction rod 140 is inserted into the hole 152 (see FIG. 6(b)) of the fixing plate 150 and fastened with the nut 160. This causes the extraction rod 140 to be locked to the main body 420 of the extraction device 400. Next, as shown in FIG. 7(c), the extraction device 400 is moved in a direction away from the conduit 20. This causes the three cables 102 to be extracted from the conduit 20 via the connecting screw shaft 130 and the extraction rod 140 (first initial extraction).

[0036] 8 is a diagram illustrating the initial removal (second time). After the first initial removal of the three cables 102 as shown in FIG. 7(c), the removal device 400 is moved (returned) toward the wall surface 32 as shown in FIG. 8(a). Then, the removal rod 140 is removed from the connecting screw shaft 130.

[0037] Next, as shown in Figure 8(b), the screw 134 of the connecting screw shaft 130 is inserted into the hole 152 of the fixing plate 150 and fastened with the nut 160. Next, as shown in Figure 8(c), when the pulling device 400 is moved in a direction away from the conduit 20, the three cables 102 are pulled out of the conduit 20 via the connecting screw shaft 130 (second initial pulling). These two initial pulling operations make it possible to pull out as much of the cables 102 as can be grasped by the main body 420 of the pulling device 400.

[0038] 9A and 9B are diagrams illustrating the operation of the extraction device 400 of this embodiment. When collectively extracting three cables 102 of a three-phase cable 100 protruding from the conduit 20 in the wall surface 32 of the manhole 30, first, as shown in FIG. 9A, the three cables 102 are inserted into the insertion hole 436 of the front main body 430a, the groove 434 of the reaction force receiving portion 430b, and the groove 444 of the rear main body 440 (see FIG. 4). Then, the front clamp 452 and the rear clamp 454 are driven by the gripping cylinder 456 to urge the cables 102 against the reaction force receiving portion 430b and the rear main body 440. As a result, the three cables 102 are gripped by the main body 420.

[0039] 9(a), when the traveling cylinder 460 is driven, the piston 460a is pushed out from the traveling cylinder 460, and as a result, the main body 420 travels on the rails 40 inside the manhole 30 and moves in a direction away from the pipeline 20, as shown in FIG. 9(b). As a result, the three cables 102 held by the main body 420 are pulled out of the pipeline 20 by a length substantially equal to the amount of movement of the main body 420.

[0040] As shown in Figure 9(b), once the main body 420 has finished moving on the rail 40, the gripping clamps (front clamp 452, rear clamp 454) release the cable 102. Then, by retracting the piston 460a, the main body 420 is moved toward the wall surface 32 as shown in Figure 9(c). Then, by repeating the above-described operations shown in Figures 9(a)-(c), the cable 102 can be pulled out from the conduit 20 and simultaneously let out the cable 102 toward the ground.

[0041] As described above, the extraction device 400 of this embodiment can collectively extract the three cables 102 constituting the three-phase cable 100 from the conduit 20 and send them out of the manhole 30. In particular, by biasing the cables 102 toward the rear main body 440 and the reaction force receiving portion 430b, which receive the reaction force, the cables 102 are stabilized and can be strongly biased, allowing them to be securely gripped. Therefore, a large extraction load can be applied to pull out all three cables at once. This significantly reduces the time required for removal work and improves work efficiency compared to conventional methods of using a hydraulic jack to extract the cables one by one.

[0042] Although the initial pulling-out (first time) and the initial pulling-out (second time) have been described as steps to be taken when the length of cable 102 protruding from wall surface 32 is short, if cable 102 has sufficient length, these steps may be omitted and the process may start from the step of grasping and pulling out cable 102. Alternatively, depending on the length of cable 102, the initial pulling-out (first time) may be omitted and the process may start from the step of initial pulling-out (second time).

[0043] The three cables 102 reeled out by the cable pulling device 400 are pushed out of the manhole 30 through the guide pipe 50 shown in Figure 1 and sent out to the ground. A transport vehicle 60 is placed on the ground, and the cable cutting device 500 is loaded on the bed of the transport vehicle 60.

[0044] The cable 102 sent out onto the ground is guided by the end of the guide pipe 50 to the cable cutting device 500, where it is cut to a length that can be loaded onto the bed of the transport vehicle 60. By cutting the cable 102 on the bed of the transport vehicle 60 in this way, the cut cable 102 can be transported by the transport vehicle 60 as is. This makes it possible to improve the efficiency of the transport work and simplify the equipment.

[0045] Up to this point, the three-phase cable 100 has been described as a POF cable, but the cable pulling device 400 of this embodiment can also be applied to other three-phase cables other than POF cables, i.e., other three-phase cables such as OF cables (Oil Filled cables) and CV (Cross-linked polyethylene insulated vinyl sheath) cables.

[0046] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention. [Industrial Applicability]

[0047] INDUSTRIAL APPLICABILITY The present invention can be used in a cable pulling device that pulls out three cables of a three-phase cable protruding from a conduit in the wall of a manhole and sends them out toward the ground. [Explanation of symbols]

[0048] 10...work site, 12...road surface, 20...pipe, 30...manhole, 32...wall, 34...bottom, 40...rail, 50...guide pipe, 60...transport vehicle, 100...three-phase cable, 102...cable, 104...skid wire, 106...conductor, 108...coating, 400...pulling device, 410...cart, 412...wheel, 420...main body, 430...front body, 430a...cable holding portion, 430b...reaction force receiving portion, 4 32...rib, 434...groove, 436...insertion hole, 440...rear body, 442...rib, 444...groove, 452...front clamp, 454...rear clamp, 456...gripping cylinder, 460...traveling cylinder, 460a...piston, 462...front end, 464...rear end, 472...manhole side plate, 474...load cell side plate, 482...end plate, 490...connecting rod, 500...cable cutting device

Claims

[Claim 1] A cable extraction device that pulls out three cables of a three-phase cable protruding from a conduit on the wall of a manhole and sends them out toward the ground, A cart that travels inside the manhole; a reaction force receiver inserted into the center of the three cables protruding from the conduit; a holding clamp that urges each of the three cables toward the reaction force receiver; a traveling cylinder that pushes the wall surface of the manhole on the pipeline side to cause the carriage to travel; A cable pulling device comprising:

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