Cable

Abstract

To provide a cable that enables easy delamination of an external semiconducting layer.SOLUTION: Two or more recesses 141 are provided on the outer periphery of an external semiconducting layer 140 of a cable 100, which comprises the external semiconducting layer 140 formed by extrusion molding.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cable. [Background technology]

[0002] High-voltage CV cables (high-voltage cross-linked polyethylene cables) are used as power cables (for example, Patent Document 1). In high-voltage CV cables, an outer semiconductive layer is disposed on the outer periphery of an insulator. In particular, in EE-type high-voltage CV cables, this outer semiconductive layer is formed by extrusion molding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-42139 A Summary of the Invention [Problem to be solved by the invention]

[0004] To peel off the outer semiconductive layer of a conventional EE type high-voltage CV cable, it is necessary to make circumferential and longitudinal cuts in the outer semiconductive layer using a cutter or a special jig, as shown in Figure 5. For example, when two longitudinal cuts are made as shown in Figure 5, the part of the outer semiconductive layer sandwiched between the two longitudinal cuts can be peeled off from the insulation, as shown in Figure 6. The longitudinal cuts have a long cut distance, and with conventional EE type high-voltage CV cables, especially when making longitudinal cuts, the cutter may go in too deep, damaging the insulation located under the outer semiconductive layer.

[0005] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a cable whose outer semiconductive layer can be easily peeled off. [Means for solving the problem]

[0006] In order to solve the above problem, a cable according to one embodiment of the present invention is a cable including an outer semiconductive layer formed by extrusion molding, and has two or more recesses provided on the outer periphery of the outer semiconductive layer. Effect of the Invention

[0007] According to the present invention, it is possible to provide a cable from which the outer semiconductive layer can be easily peeled off. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 illustrates a cable 100 according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged view of region A in FIG. [Diagram 3] 13 is a diagram illustrating how to peel off the outer semiconductive layer 140. FIG. [Figure 4] 1 is a table showing the results of a tear test. [Diagram 5] 1A to 1C are diagrams illustrating a method for peeling off the outer semiconductive layer of a conventional cable. [Figure 6] 1A to 1C are diagrams illustrating a method for peeling off the outer semiconductive layer of a conventional cable. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Cable 100> 1 is a diagram showing a cable 100 according to an embodiment of the present invention. The cable 100 has a conductor 110, an inner semiconductive layer 120, an insulator 130, an outer semiconductive layer 140, a shielding layer 150, and a sheath 170. The cable 100 is a high voltage CV cable (for example, a 6600V CV cable).

[0010] The conductor 110 is a wire for supplying electric power and is made of copper, a copper alloy, aluminum, an aluminum alloy, etc. The conductor 110 is, for example, a circular compressed strand of copper wire.

[0011] As shown in Fig. 1, the internal semiconductive layer 120 covers the outer circumference of the conductor 110 and is a semiconductive composition. This semiconductive composition is, for example, a composition containing a polyolefin resin (for example, polyethylene, ethylene-propylene copolymer, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer) and conductive carbon. The internal semiconductive layer 120 is formed, for example, by extrusion molding. Alternatively, the internal semiconductive layer 120 may be extrusion molded so as to cover the conductor 110 by wrapping a tape of the semiconductive composition around the tape.

[0012] 1, the insulator 130 covers the outer periphery of the internal semiconductive layer 120 and is an insulator such as a resin. The insulator 130 is, for example, cross-linked polyethylene. The insulator 130 is formed by, for example, extrusion molding.

[0013] 1, the outer semiconductive layer 140 covers the outer periphery of the insulator 130 and is, for example, a semiconductive composition. This semiconductive composition is, for example, a composition containing a polyolefin resin (for example, polyethylene, ethylene-propylene copolymer, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer) and conductive carbon.

[0014] The cable according to this embodiment is a so-called EE type high voltage CV cable, and the outer semiconductive layer 140 is formed by extrusion molding. When the inner semiconductive layer 120 is formed by extrusion molding, it is preferable that the three layers of the inner semiconductive layer 120, the insulator 130, and the outer semiconductive layer 140 are extruded simultaneously.

[0015] 1, the shielding layer 150 covers the outer periphery of the outer semiconductive layer 140 and is, for example, a conductor such as copper. The shielding layer 150 is formed, for example, by winding a copper tape around the outer semiconductive layer 140. When the shielding layer 150 is formed by winding a copper tape, it is preferable to wind a pressing tape 160 for pressing the copper tape around the copper tape (shielding layer 150).

[0016] 1, the sheath 170 covers the outer periphery of the shielding layer 150 and is a layer for protecting the internal layers such as the shielding layer 150. The sheath 170 is made of, for example, polyvinyl chloride.

[0017] As shown in Figures 1 and 2, two or more recesses 141 are provided on the outer periphery of the outer semiconductive layer 140 according to this embodiment. The recesses 141 are provided in the longitudinal direction of the cable 100 as shown in Figure 3. Figure 2 is an enlarged view of region A in Figure 1. In Figure 2, the shielding layer 150 is omitted from the illustration in order to explain the recesses 141 of the outer semiconductive layer 140.

[0018] 3, it is possible to peel off a portion between a pair of two adjacent recesses 141 out of the two or more recesses 141 from the insulator 130, and it is possible to easily peel off the outer semiconductive layer 140. In particular, in this embodiment, it is possible to peel off the outer semiconductive layer 140 without making a longitudinal cut with a cutter, and it is possible to reduce the possibility that the insulator 130 will be damaged by the cutter.

[0019] The thickness of the outer semiconductive layer 140 is determined by the electric power standards set by electric power companies and the Electric Cable Makers' Association standard. Therefore, in this embodiment, the thickness TR of the outer semiconductive layer 140 at the bottom of the recess (i.e., the thickness at the thinnest point of the outer semiconductive layer 140) is, for example, equal to or greater than the minimum thickness of the outer semiconductive layer set by the electric power standards set by electric power companies (0.5 mm) or equal to or greater than the thickness of the outer semiconductive layer set by the Japanese Electric Cable Makers' Association standard (approximately 0.7 mm).

[0020] <Tear test> 4 shows the results of a test performed on a 6600V CV cable with a thickness TA of the outer semiconductive layer 140 (i.e., the thickness of the outer semiconductive layer 140 other than the recesses 141) of 0.7 mm. In this test, two recesses 141 were provided on the outer periphery of the outer semiconductive layer 140, and when the portion of the outer semiconductive layer 140 between the two recesses 141 was peeled off from the insulating layer 130 as shown in FIG. 3, it was confirmed whether or not a tear occurred in the portion other than the recesses 141. In this test, the depth D of the recesses 141 and the distance I between the two recesses 141 were changed. In the table shown in FIG. 4, a circle (◯) indicates that no tear occurred in the portion other than the recesses 141, and a cross (×) indicates that a tear occurred in the portion other than the recesses 141.

[0021] As shown in FIG. 4, when the distance I between two recesses 141 is the same, the deeper the depth D of the recesses 141, the less likely tearing will occur in parts other than the recesses 141, and when the depth D of the recesses 141 is the same, the smaller the distance I between the two recesses 141, the less likely tearing will occur in parts other than the recesses 141.

[0022] 4, when the distance I between two recesses 141 is 2 mm, if the depth D of the recesses 141 is at least 0.1 mm, no tearing occurs in the portions other than the recesses 141. In this case, if the depth D of the recesses 141 is at least 0.1 mm or more and 0.4 mm or less, no tearing occurs in the portions other than the recesses 141.

[0023] Therefore, in a 6600V CV cable in which the thickness TA of the outer semiconductive layer 140 is 0.7 mm, the distance I between the two recesses 141 should be 2 mm, and the depth D of the recesses 141 should be 0.1 mm. Furthermore, in this case, the depth D of the recesses 141 may be 0.4 mm or less.

[0024] 4, when the depth D of the recesses 141 is 0.4 mm and the distance I between the two recesses 141 is 10 mm, tearing occurs in the portion other than the recesses 141, and if the distance I between the two recesses 141 is 8 mm or less, tearing does not occur in the portion other than the recesses 141. In this case, if the distance I between the two recesses 141 is at least 2 mm or more and 8 mm or less, tearing does not occur in the portion other than the recesses 141.

[0025] Therefore, in a 6600V CV cable in which the thickness TA of the outer semiconductive layer 140 is 0.7 mm, it is preferable that the distance I between the two recesses 141 is 8 mm or less and the depth D of the recesses 141 is 0.4 mm. Furthermore, in this case, the distance I between the two recesses 141 may be 2 mm or more.

[0026] Furthermore, as shown in FIG. 4, when the depth D of the recesses 141 is 0.2 mm or more and 0.4 mm or less, if the distance I between the two recesses 141 is 2 mm or more and 6 mm or less, no tearing occurs in the portions other than the recesses 141.

[0027] Therefore, in a 6600V CV cable in which the thickness TA of the outer semiconductive layer 140 is 0.7mm, the distance I between the two recesses 141 is preferably 2mm or more and 6mm or less, and the depth D of the recesses 141 is preferably 0.2mm or more and 0.4mm or less.

[0028] The present invention has been described above in terms of preferred embodiments thereof. Although the present invention has been described herein with reference to specific examples, various modifications and variations can be made to these examples without departing from the spirit and scope of the present invention as set forth in the claims. [Explanation of symbols]

[0029] 100 Cable 110 Conductor 120 Inner semiconducting layer 130 Insulator 140 Outer semiconducting layer 141 Recess 150 Shielding layer 160 Presser tape 170 Sheath

Claims

1. A cable including an outer semiconducting layer formed by extrusion, A cable having two or more recesses provided on an outer periphery of the outer semiconductive layer.

2. 10. The cable of claim 1, wherein the cable is a 6600V CV cable.

3. 3. The cable of claim 2, wherein the outer semiconducting layer has a thickness of 0.7 mm.

4. The depth of the recess is 0.1 mm or more, 4. The cable of claim 3, wherein the distance between at least one pair of two adjacent recesses of the two or more recesses is 2 mm.

5. 5. The cable of claim 4, wherein the depth of the recess is greater than or equal to 0.1 mm and less than or equal to 0.4 mm.

6. The depth of the recess is 0.4 mm; The cable according to claim 3 , wherein a distance between at least one pair of adjacent recesses among the two or more recesses is 8 mm or less.

7. The cable according to claim 6, wherein the distance between at least one pair of two adjacent recesses is equal to or greater than 2 mm and equal to or less than 8 mm.

8. The depth of the recess is 0.2 mm or more and 0.4 mm or less, 4. The cable of claim 3, wherein a distance between at least one pair of two adjacent recesses of the two or more recesses is greater than or equal to 2 mm and less than or equal to 6 mm.

9. 9. The cable of claim 1, 2, 3, 4, 5, or 8, wherein the thickness of the outer semiconducting layer at the bottom of the recess is 0.5 mm or more.

Images