Cable cutting device

Abstract

To provide a cable cutting device that can cut three-phase cables pulled out of a manhole all at once, significantly shortening a time required for removal work and improving work efficiency.SOLUTION: A cable cutting device according to the present invention is configured as a cable cutting device (cutting device 500) for cutting a three-phase cable 100 pulled out from a manhole 30, and includes a pair of opposing blades 510 (upper blade 512, lower blade 514), a frame 520 for holding the pair of blades 510, and drive units 532, 534 for moving the pair of blades 510 in a direction toward and away from each other. The pair of blades 510 are V-shaped, U-shaped, or arc-shaped with a recessed center, and cut the three-phase cable 100 all at once.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cable cutting device for cutting a three-phase cable pulled out from a manhole. [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 the power transmission system is a three-phase, three-wire system, three underground cables are buried underground as one circuit. In Patent Document 1, one power transmission cable is pulled out using a hydraulic jack and then wound up by a removal vehicle stationed on the ground. However, winding up three cables one by one takes a lot of time. This results in low work efficiency and prolonged line outages.

[0006] Therefore, the inventors thought that if the power transmission system was a three-phase three-wire system, it would be more efficient to pull out all three underground cables together and cut the three pulled underground cables. However, as a result of a cutting test using a known cutting device, it was found that while it was easy to cut a single underground cable, it was difficult to cut three underground cables (hereinafter referred to as three-phase cables) together.

[0007] In particular, POF cables (Pipe-type Oil Filled cables) are wrapped with skid wires to reduce friction with the steel pipe when they are pulled in. The skid wires are made of steel, so they are hard and tend to slip away, making them difficult to cut with a rotary blade.

[0008] In view of these problems, the present invention aims to provide a cable cutting device that can cut three-phase cables pulled out of a manhole all at once, significantly reducing the time required for removal work and improving work efficiency. [Means for solving the problem]

[0009] In order to solve the above problems, a typical configuration of a cable cutting device according to the present invention is a cable cutting device that cuts a three-phase cable pulled out of a manhole, and is equipped with a pair of opposing blades, a frame that holds the pair of blades, and a drive unit that moves the pair of blades in a direction toward and away from each other, and is characterized in that the pair of blades are V-shaped, U-shaped, or arc-shaped with a recessed center, and cut the three-phase cable all at once. [Effects of the Invention]

[0010] According to the present invention, a cable cutting device can be provided that can cut three-phase cables pulled out of a manhole all at once, significantly reducing the time required for removal work and improving work efficiency. [Brief explanation of the drawings]

[0011] [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 cutting device according to an embodiment of the present invention. [Figure 4] FIG. 3(c) is an enlarged cross-sectional view of the blade of FIG. [Figure 5] FIG. 2 is an enlarged view of the transport vehicle of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 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.

[0014] 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 underground cable 102. As shown in FIGS. 1 and 2, a three-phase cable 100 (POF cable) is laid inside a conduit 20, and the conduit 20 is filled with insulating oil (not shown) and pressurized. As shown in FIG. 2A, the three-phase cable 100 consists of three underground cables 102. As shown in FIG. 2B, a skid wire 104 is wound around the outer periphery of each of the three underground cables 102.

[0015] When removing the three-phase cable 100, first, the joints (not shown) connecting the three-phase cables 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 joints is pulled by a puller 400, whereby the three-phase cable 100 is pulled out of the conduits 20.

[0016] A transport vehicle 40 is placed on the ground, and the bed of the transport vehicle 40 is loaded with a cable cutting device of this embodiment (hereinafter referred to as cutting device 500). A guide pipe 50 is inserted from the ground into the manhole 30. As described above, the three-phase cable 100 pulled out of the conduit 20 by the pulling machine 400 is inserted into the guide pipe 50, pushed out from the manhole 30, and sent out to the ground. The end of the guide pipe 50 guides the three-phase cable 100 to the cutting device 500.

[0017] Fig. 3 is a diagram illustrating a cutting device 500 according to this embodiment. Fig. 3(a) is a front view of the cutting device 500 before cutting the three-phase cable 100. Fig. 3(b) is a side view of the cutting device 500 of Fig. 3(a). Fig. 3(c) is a top view of the cutting device 500 of Fig. 3(a). Fig. 3(d) is a front view of the cutting device 500 when cutting the three-phase cable 100.

[0018] 3 is a device that cuts a three-phase cable 100 that has been pulled out of a manhole 30 and sent out onto the ground. The cutting device 500 of this embodiment includes a pair of blades 510, a frame 520, and driving devices 532 and 534.

[0019] 3(a), the pair of blades 510 includes an upper blade 512 arranged above the three-phase cable 100 inserted into the cutting device 500, and a lower blade 514 arranged below it. The frame 520 is fixed above the stand 540, and includes an upper frame 522, a lower frame 524, and a pair of vertical frames 526a, 526b connecting them.

[0020] The upper blade 512 is held by an upper frame 522 of the frame 520, and is operated by a drive unit 532 attached to the upper frame 522 in a direction to move toward and away from the lower blade 514. The lower blade 514 is held by a lower frame 524 of the frame 520, and is operated by a drive unit 534 attached to the lower frame 524 in a direction to move toward and away from the upper blade 512. As shown in FIG. 3(b), the pair of blades 510 are disposed adjacent to each other so as to be slidable in the insertion direction of the three-phase cable 100 into the cutting device 500.

[0021] In this embodiment, of the pair of blades 510, the upper blade 512 has a V-shape with the center recessed upward. The lower blade 514 has a V-shape with the center recessed downward. Note that in this embodiment, the upper blade 512 and the lower blade 514 have been illustrated as having a V-shape, but this is not limiting. The upper blade 512 and the lower blade 514 may also have a U-shape with the center recessed, or an arc-shape with the center recessed.

[0022] Figure 4 is an enlarged cross-sectional view of blade 510 in Figure 3(c). As shown in Figure 4, upper blade 512 and lower blade 514 that make up blade 510 have their cutting edges 512a and 514a chamfered. That is, upper blade 512 and lower blade 514 are chamfered so that their cutting edges 512a and 514a form obtuse angles. This configuration can effectively prevent chipping of the blade due to hard skid wire 104 made of steel wire, allowing blade 510 to be used for a long period of time.

[0023] Furthermore, because the upper blade 512 and the lower blade 514 are V-shaped, even if the skid wire 104 slides on the surface of the cable and changes position when cutting the three-phase cable 100 (POF cable), the grooves in the upper blade 512 and the lower blade 514 can catch and cut the skid wire 104. Furthermore, although the upper blade 512 and the lower blade 514 are each composed of two combined blades, the blades are the same. This makes it easy to replace each blade, and it is possible to replace only the blade that has become chipped, or to reuse it by sharpening it.

[0024] When cutting a three-phase cable 100 using the cutting device 500 of this embodiment, first, the three-phase cable 100 is inserted between the spaced apart upper blade 512 and lower blade 514, as shown in Fig. 3(a). As shown in Fig. 3(b), the cutting device 500 of this embodiment is provided with a guide tube 550 that guides the three-phase cable 100 between the spaced apart upper blade 512 and lower blade 514. This allows the three-phase cable 100 to be efficiently inserted between the upper blade 512 and lower blade 514.

[0025] Once the three-phase cable 100 is positioned between the upper blade 512 and the lower blade 514, the drive units 532, 534 are driven. As a result, the upper blade 512 and the lower blade 514 move and slide toward each other, as shown in Figure 3(d). This prevents the skid wire 104 from slipping away, and the three-phase cable 100 is cut all at once.

[0026] Fig. 5 is an enlarged view of the transport vehicle 40 of Fig. 1. After the three-phase cable 100 is cut using the cutting device 500 as described above, the cut three-phase cable 100a is loaded onto the transport vehicle 40. Therefore, when cutting the three-phase cable 100, it is advisable to cut it into lengths L (e.g., 500 cm) that can be loaded onto the bed of the transport vehicle 40.

[0027] As described above, the cutting device 500 of this embodiment can collectively cut the three-phase cables 100 that have been pulled out of the manhole 30. Therefore, compared to the conventional method of pulling out the three underground cables 102 of the three-phase cable 100 one by one, the time required for the removal work can be significantly reduced, and work efficiency can be improved.

[0028] Furthermore, by cutting the three-phase cable 100 at predetermined lengths on the loading platform of the transport vehicle 40, a large reel is not required and the cut three-phase cable 100a can be transported as is by the transport vehicle 40. This also makes it possible to improve the efficiency of the transport work and simplify the equipment.

[0029] 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]

[0030] The present invention can be used in a cable cutting device that cuts a three-phase cable pulled out from a manhole. [Explanation of symbols]

[0031] 10...work site, 12...road surface, 20...pipe, 30...manhole, 40...transport vehicle, 50...guide pipe, 100...three-phase cable, 100a...three-phase cable, 102...underground cable, 104...skid wire, 400...pulling machine, 500...cutting device, 510...blade, 512...upper blade, 514...lower blade, 520...frame, 522...upper frame, 524...lower frame, 526a...vertical frame, 526b...vertical frame, 532...drive unit, 534...drive unit, 540...stand, 550...guide tube

Claims

[Claim 1] A cable cutting device for cutting a three-phase cable pulled out from a manhole, A pair of opposing blades; a frame for holding the pair of blades; a drive device that moves the pair of blades in a direction toward and away from each other; Equipped with The pair of blades are V-shaped, U-shaped, or arc-shaped with a recessed center, and are adapted to cut the three-phase cables all at once.

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