JP4966212B2 - Cable jumper wire coating - Google Patents

Description

  The present invention relates to a covering film for a cable jumper wire in which a switch for electrical work is temporarily installed on a utility pole, and a lead cable extending from the switch is connected to an aerial distribution line. More specifically, the cable jumper wire It is related with the film | membrane which coat | covers the strand which comprises A, and a connection terminal.

  When electrical work is performed, as shown in FIG. 2, a switch 92 is temporarily installed on a utility pole 91, and lead cables 93 extending from the switch to both sides are connected to an overhead distribution line 95 through cable jumper wires 94. Sometimes. Then, while performing the opening / closing operation of the switch, the aerial distribution line is cut in the vicinity of the utility pole, and the desired electrical work is performed.

  Lead cables are very hard and difficult to bend, and connecting them directly to the overhead distribution line is a heavy work burden for the operator, so that the cable jumper wire that is easy to bend is connected to the overhead distribution line. It was decided to connect between them.

  Normally, after about a week, the electrical work is completed, and the switch and cable jumper wires are removed, but after that, they are transported and used many times for another electrical work. Therefore, the cable jumper wire was disconnected while continuing to bend and stretch the cable jumper wire. When examined, the disconnection point usually occurred at the same position, but the disconnection point could not be determined by a simple visual inspection. This seems to be caused by the structure of the conventional cable jumper wire.

  As the conventional cable jumper wire 94, as shown in FIG. 3, the connection terminals 97 are fixed to both ends of the wire 96 which is a conductor, and the outside of the wire is covered with a flexible and opaque wire protection tube 98, It is known that the outside of the connection portion between the connection terminal and the wire is covered with a hard terminal protection pipe 99 that is difficult to bend.

  In order to prevent bending stress from concentrating at the boundary between the connection terminal that does not bend at all and the flexible strand, this was done, but instead, at the end of the terminal protection pipe near the strand. I started to break. This is presumed to be due to the great difference in bending strength between the terminal protection pipe and the wire.

  Since the disconnection point is the end portion of the terminal protection pipe near the strand as described above, if both the terminal protection pipe and the strand protection tube are transparent, the strand can be visually observed. Actually, the terminal protection pipe and the wire protection tube are made of a weather-resistant opaque insulating material so that they are not easily cracked due to the influence of ultraviolet rays due to the installation outdoors. It was. That is, since it is opaque, it was not possible to visually observe the inner strand through the terminal protection pipe and the strand protection tube. Moreover, since the hard terminal protective pipe is covered on the end portion of the strand protection tube, the strand protection tube cannot be wound from the end. Therefore, in order to investigate the disconnection, it was impossible to examine the progress of the disconnection other than destroying the terminal protection pipe and the strand protection tube.

  If disconnection progresses, power will not be supplied even if the switch is closed, causing a power failure. In order to prevent such a situation, the cable jumper wire has a fixed lifetime, and after the lifetime (usually several years) has passed, it is replaced with a new one regardless of whether there is a break. It was.

There is no patent document of the same technology as the cable jumper wire mentioned above, but as a related matter from the viewpoint of preventing disconnection, the wire does not bend suddenly in the vicinity of the connection part, so that there is no possibility of damage or disconnection of the wire. In order to do this, there is known one that covers the outside in the vicinity of the connecting portion with a protective cover (Patent Document 1).
Japanese Unexamined Patent Publication No. 7-46728

  The present invention was created in consideration of the above-mentioned circumstances, and the problem to be solved is that the wire can be visually observed while covering the periphery in the vicinity of the connection portion between the wire and the connection terminal, and the wire breaks off. It is an object of the present invention to provide a coating film for a cable jumper wire that can accurately determine whether or not it can be used depending on the situation.

  The present invention connects the connection terminal to the end of the strand, covers the outer periphery of the strand with a flexible strand protection tube, and connects the outer periphery in the vicinity of the connection boundary between the strand and the connection terminal to the terminal protection pipe and It is premised on the covering film of the cable jumper wire that is covered and insulated with the protective tube for wire, and the wire breakage due to bending stress is provided closer to the wire than the connection boundary due to the hardness of the protective pipe for terminal .

  The invention according to claim 1 is a multilayer film in which the outer periphery in the vicinity of the connection boundary is concentrically covered with a transparent inner layer and an opaque outer layer covering the inner layer, and the multilayer film is a non-turnable terminal. When a wire protection tube and a wire protection tube that can be wound are used as the outer layer, and the end of the wire protection tube is rolled up, the diameter gradually decreases from the connection boundary toward the wire. In addition, the inner layer is formed and a transparent protective film is used for the inner layer, and the step portion between the large-diameter portion and the small-diameter portion of the inner layer is used as the disconnection portion, so that the bending strength in the vicinity of the connection boundary is based on the step portion. The inner layer and the outer layer are formed so that the connection boundary side is stronger than the opposite side.

  Two or more step portions between the large diameter portion and the small diameter portion of the inner layer may be provided, but in order to make it easier to design the disconnection portion, there is only one step portion, and as in claim 2 desirable. That is, the multilayer film has a bending strength in the vicinity of the connection boundary, with the step portion between the large-diameter portion and the small-diameter portion of the inner layer as a reference location, the opposite side of the connection boundary is weak, the connection boundary side is in order, medium, and strong. In this state, an inner layer and an outer layer are formed.

  In addition, as an example of a specific structure of the coating film, as in claim 3, as a protective film for the inner layer, a transparent inner tube disposed between the strand protection tube and the strand, and a terminal A transparent inner pipe arranged between the protective pipe and the element wire is provided, and both end faces of the terminal protection pipe and the element protection tube are provided close to each other, and the terminal protection pipe and the element protection are provided. The inner layer is formed by overlapping the inner tube and the inner pipe in the order of the inner tube and the inner pipe on both sides of the tube 3b as the boundary, and the bending strength is related to the multilayer structure of the terminal protection pipe and the inner pipe. > Multi-layer structure of wire protection tube and inner pipe> Single-layer structure of wire protection tube.

  According to the present invention, if the end portion of the protection tube for strands is turned, the inner layer that gradually decreases in diameter can be visually observed, and since the inner layer is transparent, the disconnection state of the inner strands can be grasped. It is possible to accurately determine whether or not it can be used according to the progress status.

  According to the invention of claim 2, since the bending strength in the vicinity of the connection boundary can be set in three stages, by appropriately setting the hardness of the large diameter portion of the inner layer, the large diameter portion and the small diameter portion of the inner layer The step portion can be easily set as a disconnection portion.

  According to the third aspect of the present invention, the large diameter portion and the small diameter portion of the inner layer can be easily created by the inner pipe disposed on the inner side of the terminal protection pipe, and the stepped portion is easily set to the broken portion. be able to.

  As shown in FIG. 1, the cable jumper wires are formed by connecting conductive metal connection terminals 2 to both ends in the longitudinal direction of a single thick strand 1 in which a plurality of conducting wires are bundled. The outer periphery in the vicinity of the connection boundary K and the outer periphery over the entire length of the strand 1 are covered and protected by a coating film 3 made of an insulating material.

  The connection terminal 2 is formed by applying pressure to one end of a cylindrical sleeve 21 to form a flat plate 22. The end of the wire 1 is inserted into the sleeve 21, and the sleeve 21 is crimped to narrow the diameter. The wire 1 is connected, and the flat plate 22 is provided with a hole 23 for fastening with a bolt, a nut or the like (not shown).

  The covering film 3 is an insulator made of a multilayer film in which a plurality of protective films 3a, 3b,... Are arranged concentrically. The covering film 3 has two layers of protective films 3a and 3b on the outside in the longitudinal direction of the strand 1, that is, a transparent inner tube 3a that covers the outside of the strand 1, and an outer side of the inner tube 3a. It has a two-layer structure with an opaque protective tube 3b for covering the wire.

  On the other hand, in the vicinity of the connection boundary K between the wire 1 and the connection terminal 2, the coating film 3 covers the outside of the wire 1 until the inner tube 3 a described above has a slight gap G toward the connection terminal 2. The both sides of the connection boundary K are covered with the inner pipe 3c having a two-layer structure, and the inner pipe 3c is harder than the inner tube 3a. Further, the inner pipe 3c is covered with the strand protection tube 3b outside the inner tip (the tip of the portion extending from the connection boundary K to the strand side), and the outer portion of the remaining portion of the inner pipe 3c is protected for the terminal. It is covered with a pipe 3d, and the outside of the connection terminal 2 is partially covered directly by a part of the terminal protection pipe 3d.

  By covering as described above, as shown in FIG. 1 (a), the end faces of the terminal protection pipe 3d and the strand protection tube 3b come close to each other, and the strand 1 is connected from the connection boundary K. The four-layer structure region A of the terminal protection pipe 3d, the two-layer inner pipe 3c, and the inner tube 3a, and the four-layer structure of the strand protection tube 3b, the two-layer inner pipe 3c, and the inner tube 3a. Three regions C having a two-layer structure of region B, a wire protection tube 3b and an inner tube 3a are formed in order.

  When the end portion of the strand protection tube 3b is turned, the outer diameters of the three regions A, B, and C are stepped from the connection boundary K toward the strand 1 as shown in FIG. By adopting protective films of various hardnesses, the bending strength of the three regions A, B, and C is increased from the connection boundary K toward the element wire 1 to be strong, medium, and weak. The disconnection location due to the bending stress associated with the use is set to the stepped portion O between the middle region B and the weak region C. To be precise, the disconnection points are concentrated in the vicinity of the stepped portion O. Since the inner tube 3a exists in all three regions A, B, and C, the relationship of bending strength can be ignored. As a result, the relationship of bending strength is a complex of the terminal protection pipe 3d and the inner pipe 3c. Layer structure> Multi-layer structure of wire protection tube 3b and inner pipe 3c> Single-layer structure of wire protection tube 3b.

  The three regions A, B, and C use an opaque terminal protection pipe 3d and a strand protection tube 3b for the outer layer of the multilayer film, and a transparent protective film (for the inner layer of the multilayer film). Since the inner pipe 3c and the inner tube 3a) are used, the wire 1 can be visually observed through the transparent inner layer in the two regions B and C when the end portion of the strand protection tube 3b is turned.

  The inner pipe 3c has a transparent two-layer structure. An adhesive tape (for example, a raw material: vinyl chloride film) is used for the inner film 3c1, and the adhesive tape is wound around the connection terminal 2 and the inner tube 3a in a spiral shape a plurality of times. A hard inner film 3c1 is formed, and a cylinder made of silicone rubber is used for the outer film 3c2, and a soft outer film 3c2 is fitted outside the hard inner film 3c1. In the drawing, the adhesive tape is wound many times on both sides around the right end of the terminal protection pipe 3d, and the inner film 3c1 is hardened by the thickness.

  The inner tube 3a is transparent and has a flexibility that hardly inhibits the bending of the element wire 1. For example, a vinyl chloride mixture is used as a raw material.

  The strand protection tube 3b is opaque, hardly disturbs the bending of the strand 1, and has flexibility to bend from the end as shown in FIG. For example, ethylene propylene rubber is used as a raw material. The method of covering the outside of the inner tube 3a with the wire protection tube 3b is to prepare a wire protection tube 3b that is spread outside the shrink tube (not shown), and the inner tube 3a is provided in the shrink tube. And then remove the shrink tube. In the shrinkable tube, a break line is formed in a spiral shape on the inner peripheral surface of the cylinder, and as a result, a thin resin ribbon is wound into a spiral shape to form a cylindrical shape. It will unwind from one end. If it does in this way, the protection tube 3b for strands will shrink | contract from the location where the ribbon was unwound, and will cover the outer side of the inner tube 3a.

  The terminal protection pipe 3d is opaque, is hard (so that it cannot be broken) and has excellent weather resistance such as ultraviolet rays, for example, a raw material, so that bending stress is applied to the strand side from the connection boundary K. When polyolefin is used and inserted in a state where there is play on the outside of the connection terminal 2 and the inner pipe 3c and then heat is applied, the connection terminal 2 and the like are tightened and integrated by heat shrinkage.

  The above-described coating film 3 of the cable jumper wire is judged to be usable with little breakage by visually checking the strand 1 over the inner layer over the end of the strand protection tube 3b due to its flexibility. In this case, the wire protection tube 3b can be returned to its original shape and used as it is.

  The present invention is not limited to the above embodiment. For example, the outer sides of the strand protection tube 3b and the terminal protection pipe 3d may be covered with a flexible opaque adhesive tape.

(A)-(C) is a principal part sectional view showing a covering film of a cable jumper wire, a principal part sectional view showing a state in which a protection tube for wire is wound, and a front view of the cable jumper wire. It is explanatory drawing which shows the use condition of a cable jumper wire, and a cable jumper wire. It is sectional drawing which shows the coating film of the conventional cable jumper wire.

Explanation of symbols

1 wire, 2 connection terminals, 3 coating film, 3a inner tube, 3b wire protection tube,
3c inner pipe, 3c1 inner film, 3c2 outer film, 3d terminal protection pipe,
K connection boundary, O stepped portion, G gap, A region, B region, C region

Claims (3)

The connection terminal (2) is connected to the end of the element wire (1), the outer periphery of the element wire (1) is covered with a flexible element protection tube (3b), and the element wire (1) and the connection terminal (2 The outer periphery in the vicinity of the connection boundary (K) with the terminal is covered with a terminal protection pipe (3d) and a wire protection tube (3b) for insulation, and the broken portion of the wire (1) due to bending stress is protected. In the coating film of the cable jumper wire provided on the strand (1) rather than the connection boundary (K) due to the hardness of (3d),
A multilayer film in which the outer periphery in the vicinity of the connection boundary (K) is concentrically covered with a transparent inner layer and an opaque outer layer covering the inner layer,
When the multi-layered film uses a non-turnable terminal protection pipe (3d) and a turnable wire protection tube (3b) as its outer layer, the end of the wire protection tube (3b) is rolled up. The inner layer is formed in a shape that gradually decreases in diameter from the connection boundary (K) toward the strand (1), and a transparent protective film is used for the inner layer. In order to make the stepped portion (O) of the wire the disconnection portion, the bending strength in the vicinity of the connecting boundary (K) is set so that the connecting boundary (K) side is stronger than the opposite side with respect to the stepped portion (O). An outer layer is formed on the cable jumper wire covering film.   In the multilayer film, the bending strength in the vicinity of the connection boundary (K) is weak on the opposite side of the connection boundary (K) with the stepped portion (O) between the large-diameter portion and the small-diameter portion of the inner layer as a reference location. 2. The cable jumper wire covering film according to claim 1, wherein the inner layer and the outer layer are formed in a state in which the K) side is in the middle and the stronger. As a protective film for the inner layer, a transparent inner tube (3a) disposed between the protective tube for wire (3b) and the wire (1), and between the terminal protective pipe (3d) and the wire (1) Each having a transparent inner pipe (3c) disposed in
Both end faces of the terminal protection pipe (3d) and the strand protection tube (3b) are provided close to each other, and the terminal protection pipe (3d) and the strand protection tube (3b) are located at the proximity of each other. The inner tube (3a) and the inner pipe (3c) are overlapped on the outer side of the strand (1) in this order on both sides of the inner side to form an inner layer,
The relationship of bending strength is as follows: multi-layer structure of terminal protection pipe (3d) and inner pipe (3c)> multi-layer structure of strand protection tube (3b) and inner pipe (3c)> strand protection tube (3b) 3. The cable jumper wire covering film according to claim 2, wherein the coating film is a single layer structure.

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