JP2005094973A - Strain-relieving device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a strain-relieving device that does not require an insulator when wiring a leading wire into a house from a pole and that is lighter than a conventional device. <P>SOLUTION: The strain-relieving device 10 has an electric wire fixing portion 12 where the leading wire is fixed and a mounted-on-building-side potion 14 that is mounted on the wall of a building like a house. The electric wire fixing portion 12 and the mounted-on-building-side portion 14 are connected to each other by a strain holding means 16 and electrically insulated to each other. The strain-holding means 16 has a rope-shaped strain member 18 and a holding member, or a fusing member 20 that holds the strain member 18 in a slackened state. The fusing member 20 breaks when an abnormal voltage is applied between the electric wire fixing portion 12 and the mounted-on-building-side portion 14 with the length of the strain-relieving device extended and abnormal tension is relieved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tension relaxation device for relaxing abnormal tension of a lead-in wire.

  In order to draw electric wires for power supply, communication, etc. into a house, a lead-in wire is generally wired from the utility pole to the house, except for the use of a buried cable that has been adopted in part in recent years. An insulator is used between the lead-in wire and the house for the purpose of maintaining electrical insulation and the purpose of fixing the wire for the lead-in wire. The insulator on the house side is attached to the wall of the house using a suitable fixing tool. The tension due to the lead-in wire between the utility pole and the house is received by the insulator on the house side, but the lead-in line is loosened moderately between the utility pole and the house so that excessive tension does not occur at the insulator installation point on the house wall. Is wired. Between the house side location where the lead-in wire wired from the utility pole is fixed to the insulator to the interior wiring, there is a connection location between the wires, and the connection location is wired so that no tension is applied .

  When using such an insulator, when the lead wire is subjected to an abnormal tension greatly exceeding the above-mentioned fixed tension due to the inclination of the power pole, strong wind, or the weight of the attached ice and snow, the lead wire breaks due to the tension, or The wall of the house where the insulator is attached may break the lead-in wire under the abnormal tension without being supported. In the latter case, if the fixture is screwed and fixed, damage to the screwed part will occur, such as cracks in the wall, and rainwater will enter the house due to subsequent wind and rain, causing the columns to corrode. In some cases, such as failure.

  In order to prevent such breakage of the electric wire or damage to the wall of the house, various tension relaxation devices have been developed. For example, Patent Document 1 discloses an apparatus having a buffer fitting curved in an Ω-shape and a clasp that maintains the buffer fitting in an Ω-shape. This device has a function of relaxing the abnormal tension by extending the entire length of the buffer fitting when the clasp is released and the curved shock-absorbing metal fitting is extended when abnormal tension is applied. Patent Document 2 discloses a tension relaxation device having an outer cylinder in which a plurality of locking portions are provided in the axial direction and an inner cylinder that can be locked at each of the locking portions. When an abnormal tension is applied, this device is extended in a stepwise manner according to the position of the locking portion, and the abnormal tension is alleviated. Further, Patent Document 3 discloses a shock absorber for an electric wire having a coil spring and a detachable connecting member. This device is compressed when the abnormal tension is applied, the coil spring is compressed, and the connecting member is removed to extend the entire length. , Relieve abnormal tension.

Japanese Patent Laid-Open No. 11-164460 JP-A-7-107647 JP 2000-134778 A

  The conventional tension relief device as described above is mainly made of metal from the viewpoint of strength. Therefore, in order to reliably insulate the service line from the wall of the house, it is necessary to connect the service line and the tension relaxation device via an insulator made of an insulating material such as porcelain.

  Then, an object of this invention is to provide the tension | tensile_strength relief apparatus which does not require an insulator separately.

In order to achieve the above-mentioned object, the invention according to claim 1 connects an electric wire fixing portion to which an electric wire is fixed, a building-side attachment portion attached to a building, and the electric wire fixing portion and the building-side attachment portion. Tension holding means, and when a predetermined tension is applied between the wire fixing portion and the building-side mounting portion, the distance between the wire fixing portion and the building-side mounting portion is In the tension relaxation device configured to extend by a predetermined distance, a portion of the wire fixing portion where the electric wire is fixed and a portion of the building-side attachment portion attached to the building are electrically insulated from each other. There is provided a strain relief device.
That is, according to the invention which concerns on Claim 1, the tension | tensile_strength relief apparatus which can be used without requiring a lever is provided.

According to a second aspect of the present invention, in the tension relaxation device according to the first aspect, the tension holding means includes a flexible tension member and a holding member that holds the tension member in a relaxed state. And the holding member is configured not to hold the tension member in a relaxed state when a predetermined tension is applied between the wire fixing portion and the building-side mounting portion. A tension relief device is provided.
That is, according to the second aspect of the present invention, there is provided a tension alleviating device in which the full length is extended by approaching the tension member from the relaxed state to the tensioned state when an abnormal tension is applied.

According to a third aspect of the present invention, there is provided the tension relaxation apparatus according to the second aspect, wherein the tension member is made of an insulating material.
That is, according to the invention which concerns on Claim 3, the tension | tensile_strength relaxation apparatus by which between the electric wire fixing | fixed part and the building side attaching part was electrically insulated is provided.

According to a fourth aspect of the present invention, there is provided the tension relaxation apparatus according to the third aspect, wherein the holding member is made of an insulating material.
That is, according to the invention which concerns on Claim 4, the electrical insulation between an electric wire fixing | fixed part and a building side attaching part is further ensured.

According to the present invention, the following effects can be obtained.
In the tension relaxation device according to the present invention, since the electric wire fixing portion and the building-side mounting portion are insulated, there is no need for an insulator that has been conventionally used in the wiring of the lead-in wire, and the work efficiency and cost can be greatly reduced. Is possible.

Hereinafter, the present invention will be described in detail with reference to the drawings.
Fig.1 (a) shows the tension | tensile_strength relaxation apparatus 10 of the 1st Embodiment of this invention. The strain relief device 10 includes an electric wire fixing portion 12 to which a lead-in wire wired from the main line is fixed, and a building-side attachment portion 14 that is preferably attached to a wall of a building such as a house via an appropriate fixing tool. The wire fixing portion 12 and the building-side mounting portion 14 are connected to each other by the tension holding means 16. The tension holding means 16 includes, for example, a rope-like flexible tension member 18 and a holding member that holds the tension member 18 in a relaxed state, that is, a fuse member 20. In the present embodiment, the fuse member 20 is a rope-like member shorter than the tension member 18, and the tension member 18 is relaxed such as being bent or wound between the wire fixing portion 12 and the building-side attachment portion 14. Keep in state. The strength of the tension member 18 and the fuse member 20 can be arbitrarily changed depending on the material and diameter thereof.

  In the present embodiment, the wire fixing portion 12 that is an independent member may have any structure as long as the lead-in wire can be fixed, but is preferably widely used as a so-called thimble shown in FIG. It has an annular shape. Furthermore, as shown in FIG. 1B, it is preferable that a groove for aligning the tension member 18 and the fuse member 20 is provided on the outer periphery of the annular wire fixing portion 12. In this case, the connection between the wire fixing portion 12 and the tension member 18 and the fuse member 20 is achieved by, for example, extending the tension member 18 and the fuse member 20 about one turn in the outer peripheral groove of the wire fixing portion 12 and connecting the ends thereof. This is possible by joining the portion to the tension member 18 and the other part of the fuse member 20. Specifically, a relatively simple method of compressing and joining the end portions of the tension member 18 and the fuse member 20 to other portions using, for example, an aluminum joining member 22 as shown in the drawing is possible. is there. With such a configuration, the tension member 18 and the fuse member 20 can be easily and reliably connected to the wire fixing portion 12.

  In the present embodiment, the building-side mounting portion 14, which is an independent member, may have any structure as long as it can be attached directly to the wall of the house or to a fixture provided on the wall of the house, but is preferably fixed to the electric wire. Similar to the portion 12, for example, it has an annular shape that is widely used as a so-called thimble shown in FIG. As shown in FIG. 1C, a groove for extending the tension member 18 and the fuse member 20 may be provided on the outer periphery of the annular building-side mounting portion 14 as shown in FIG. preferable. However, since the building-side mounting portion 14 is preferably of a size suitable for mounting on the wall of the house, it is not necessary to have the same size as the wire fixture 12 (in the illustrated example, the building-side mounting portion 14 Is small). The connection method between the building-side mounting portion 14 and the tension member 18 and the fuse member 20 can be the same as the connection method between the wire fixing portion 12 and the tension member 18 and the fuse member 20 described above. With such a configuration, the tension member 18 and the fuse member 20 can be easily and reliably connected to the building-side mounting portion 14.

  A major feature of the tension relaxation device 10 according to the present invention is that the tension member 18 and the fuse member 20 are made of an insulating material. As a result, the wire fixing portion 12 and the building-side mounting portion 14 are electrically insulated from each other, and there is no need to use an insulator made of porcelain or the like in the lead-in wiring. The insulating material is preferably a material selected from the group including para-aromatic polyamide fibers, polyparaphenylene benzobisoxazole (PBO) fibers, high-strength polyethylene fibers, and polyarylate fibers. These materials are generally known as high strength synthetic fibers and are lighter than metals of comparable strength. Therefore, the tension relaxation apparatus according to the present invention is lighter than the conventional one as a whole, is easy to handle, and is effective in reducing the load on the lead-in wire and the wall of the house. Furthermore, these materials can be improved in weather resistance by being coated with a thermoplastic elastomer excellent in weather resistance such as polyurethane, polyester and polyolefin, or rubber excellent in weather resistance such as EPDM.

  As materials for the electric wire fixing portion 12 and the building-side mounting portion 14, synthetic rubbers such as EPDM, chloroprene rubber, silicone rubber and nitrile rubber, and synthetic resins such as nylon 6, nylon 6,6, polyethylene and polyvinyl chloride are used. preferable. These materials are lighter than metals and have excellent weather resistance. Furthermore, since these materials are also substantially insulating materials, the electrical insulation between the electric wire fixed to the electric wire fixing portion 12 and the wall of the house via the building-side mounting portion 14 is ensured.

  When at least one of the wire fixing portion 12 and the building-side mounting portion 14 is made of the above-described synthetic rubber or synthetic resin, the tension member 18 and the fuse member 20 constituting the tension holding means 16 are not made of an insulating material. No strain relief is possible. Also in this case, it is possible to insulate between the portion of the wire fixing portion 12 where the electric wire is fixed and the portion of the building-side attachment portion attached to the building. However, in that case, it is necessary to be configured so that the lead-in wire and the wall or fixture of the house cannot contact the tension member 18 and the fuse member 20.

Next, the usage method of the tension relaxation apparatus 10 is demonstrated.
As shown in FIG. 2, the tension relaxation device 10 is used in a state where the lead-in wire C is fixed to the electric wire fixing portion 12 and the building-side attachment portion 14 is attached to the wall W of the house. The lead-in wire C is further wired from the electric wire fixing portion 12 toward the house in a properly stretched state. On the other hand, the building-side attachment portion 14 is attached to a fixture 24 such as a hook provided on the wall W of the house. As described above, since the wire fixing portion 12 and the building-side mounting portion 14 are insulated, it is not necessary to separately provide an insulator or the like. This means that there is no need for labor and cost related to the insulators that have been conventionally required, which is a great advantage. Further, since the insulator is unnecessary and the tension relaxation device itself is light, handling is facilitated and the force applied to the wall W of the house at the attachment site of the fixture 24 is reduced. This is also a great advantage.

  The tension relief device 10 according to the present invention relaxes the tension of the lead-in wire when an abnormal tension is applied to the lead-in due to a gradual inclination or displacement of the utility pole, strong wind or icing on the lead-in wire, etc. It has the effect of preventing breakage of the attachment portion (for example, the wall of a house) of the lead-in wire. The fuse member 20 is configured to be broken when an abnormal tension exceeding a predetermined tension is applied. That is, when an abnormal tension exceeding a predetermined tension is applied to the lead-in wire C due to the inclination of the utility pole, a tension equivalent to the abnormal tension is applied between the wire fixing portion 12 and the building-side mounting portion 14 of the tension relaxation device 10. The fuse member 20 is broken by the abnormal tension. Thereby, the tension member 18 in a relaxed state approaches a tensioned state, and the distance between the electric wire fixing portion 12 and the building-side attachment portion 14, that is, the entire length of the tension relaxation device 10 is extended. On the other hand, since the lead-in wire C and the strain relief device 10 wired between the main line and the wall of the house can be considered as a substantial suspension line as a whole, the overall length of the tension relief device 10 is extended by the length of the suspension line. Means that it grows. Therefore, the abnormal tension applied to the lead-in wire C and the tension relief device 10 before the fuse member 20 breaks is relieved, and the breakage of the lead-in wire and the destruction or damage of the wall of the house to which the tension relief device 10 is attached are prevented. . In addition, since it can be easily determined from the appearance that the fuse member 20 has been blown, replacement with another tension relief device can be performed quickly.

  The tension member 18 preferably has a diameter larger than that of the fuse member 20, that is, a high breaking strength. Thus, after the fuse member 20 is broken, the tension relief device 10 can withstand a higher tension than the tension that caused the fuse member 20 to break.

  Next, a tension relaxation device 30 according to a second embodiment of the present invention will be described with reference to FIGS. The strain relief device 30 has the same configuration as the strain relief device 10 except that the holding member is not a fuse member but a fastening member. That is, the tension relaxation device 30 includes an electric wire fixing portion 32 to which a lead-in wire wired from the main line is fixed, and a building-side attachment portion 34 that is preferably attached to a wall of a building such as a house via an appropriate fixing tool. . The electric wire fixing portion 32 and the building-side attachment portion 34 are connected to each other by the tension holding means 36. The tension holding means 36 includes, for example, a rope-like flexible tension member 38 and a holding member that holds the tension member 38 in a relaxed state, that is, a fastening member 40. In the present embodiment, the tension member 38 is held in a relaxed state such as being bent or wound between the wire fixing portion 32 and the building-side mounting portion 34 by the holding member or the fastening member 40.

  The wire fixing part 32 and the building side mounting part 34 may have any structure as long as the lead-in wire can be fixed, but preferably the same as the wire fixing part 12 and the building side mounting part 14 of the tension relaxation device 10. It has an annular shape. Furthermore, it is preferable that a groove is provided on the outer periphery of the ring-shaped electric wire fixing portion 32 and the building-side mounting portion 34 so that the tension member 38 is aligned. In this case, the connection between the electric wire fixing portion 32 and the tension member 38 is performed by extending the tension member 38 along the outer circumferential groove of the electric wire fixing portion 32 about the other end of the other portion of the tension member 38. Can be joined. Specifically, for example, a relatively simple method of compressing and joining the end portion of the tension member 38 and the other portion is possible using a joining member 42 made of, for example, aluminum as illustrated.

  The building-side attachment portion 34 may have any structure as long as it can be attached directly to the wall of the house or to a fixture provided on the wall of the house, similarly to the building attachment portion 14 of the strain relief device 10. Has an annular shape similar to that of the wire fixing portion 32. Similarly to the wire fixing portion 32, it is preferable that a groove for the tension member 38 is provided on the outer periphery of the annular building-side mounting portion 34. However, since the size of the building-side mounting portion 34 is preferably a size suitable for mounting on the wall of the house, the size of the building-side mounting portion 34 is not necessarily the same as the size of the electric wire fixture 32 (in the illustrated example, the building-side mounting portion 34 is more small). The connection method between the building-side mounting portion 34 and the tension member 38 can be the same as the connection method between the wire fixing portion 32 and the tension member 38 which has been operated.

  Each of the joining members 42 further has a tab 44 with which the fastening member 40 can be engaged. More specifically, for example, the two end portions 40a and 40b of the fastening member 40 are both bowl-shaped as shown in FIG. 3B, while the tab 44 has the end portions 40a and 40b of the fastening member 40. 40b has holes 44a and 44b that are engageable with each other. The fastening member 40 is configured such that at least one of the end portions 40a and 40b is detached from the holes 44a and 44b of the tab 44 when an abnormal tension is applied between the wire fixing portion 32 and the building-side mounting portion 34. . More specifically, for example, when an abnormal tension is applied, one of the end portions 40a and 40b (end portion 40a in the illustrated example) of the fastening member 40 is deformed so as to be closer to a straight line from the saddle shape, As a result, the end portion 40a is detached from the hole 44a of the tab 44. In this way, the entire length of the tension relief device 30 is extended, and the abnormal tension is alleviated.

  A major feature of the tension relaxation device 30 according to the present invention is that the tension member 38 and the fastening member 40 are made of an insulating material. As a result, the electric wire fixing portion 32 and the building-side mounting portion 34 are electrically insulated from each other, and there is no need to use an insulator made of porcelain or the like in the lead-in wiring. The insulating material is preferably a material selected from the group including para-aromatic polyamide fibers, polyparaphenylene benzobisoxazole (PBO) fibers, high-strength polyethylene fibers, and polyarylate fibers. These materials are generally known as high-strength synthetic fibers, have the advantage that they are lighter than metals of the same strength, and are further superior in weather resistance such as polyurethane, polyester, polyolefin, etc. The weather resistance can be improved by coating with rubber having excellent weather resistance such as the above.

  As materials for the electric wire fixing portion 32 and the building-side mounting portion 34, synthetic rubbers such as EPDM, chloroprene rubber, silicone rubber and nitrile rubber, and synthetic resins such as nylon 6, nylon 6,6, polyethylene and polyvinyl chloride are used. preferable. These materials are lighter than metals and have excellent weather resistance. Furthermore, since these materials are also substantially insulating materials, the electrical insulation between the electric wire fixed to the electric wire fixing portion 32 and the wall of the house via the building-side mounting portion 34 is ensured.

  When at least one of the wire fixing portion 32 and the building-side attachment portion 34 is made of the above-described synthetic rubber or synthetic resin, the tension member 38 and the fastening member 40 constituting the tension holding means 36 are not made of an insulating material. No strain relief is possible. Also in this case, it is possible to insulate between the portion of the electric wire fixing portion 32 where the electric wire is fixed and the portion of the building-side attachment portion 34 attached to the building. However, in that case, it is necessary to be configured so that the lead-in wire and the wall or fixture of the house cannot contact the tension member 38 and the fastening member 40.

  The method of using the tension relaxation device 30 is the above-described tension relaxation device except that, instead of the fuse member 20 breaking, at least one end portion of the fastening member 40 is removed so that the entire length of the tension relaxation device 30 is extended. This is the same as the method of using 10.

  In the embodiment described above, the wire fixing portion, the building-side attachment portion, the tension member and the fuse member constituting the tension holding means are described as independent members, but all or some of these constituent members are It may be a single object. For example, both ends of a rope-shaped member made of an insulating material are formed in an annular shape as an electric wire fixing portion and a building-side attachment portion, respectively, and the space between the electric wire fixing portion and the building-side attachment portion (this portion corresponds to a tension member) A tension relief device configured to be held in a relaxed state by a holding member (for example, a fuse member or a fastening member) is also possible.

(A) It is the schematic of the whole tension relaxation apparatus of 1st Embodiment which concerns on this invention, (b) It is an AA arrow line view which shows the electric wire fixing part of the tension relaxation apparatus of (a), c) It is a BB arrow line view which shows the building side attaching part of the tension relaxation apparatus of (a). It is a figure which shows the usage condition of the tension relaxation apparatus which concerns on this invention. (A) It is the schematic of the whole tension relaxation apparatus of 2nd Embodiment which concerns on this invention, (b) It is CC arrow line view which shows the securing member of the tension relaxation apparatus of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 30 ... Tension relaxation device 12, 32 ... Electric wire fixing | fixed part 14, 34 ... Building side attaching part 16, 36 ... Tension holding means 18, 38 ... Tension member 20 ... Fuse member 22, 42 ... Joint member 40 ... Fastening Member 44 ... Tab C ... Lead-in wire W ... Wall

Claims (4)

An electric wire fixing portion to which an electric wire is fixed, a building side mounting portion to be attached to a building, and a tension holding means for connecting the electric wire fixing portion and the building side mounting portion, the electric wire fixing portion and the building In a tension relaxation device configured such that when a predetermined tension is applied to the side mounting portion, the distance between the electric wire fixing portion and the building side mounting portion is extended by a predetermined distance.
A portion of the electric wire fixing portion to which the electric wire is fixed and a portion of the building-side attachment portion attached to the building are electrically insulated from each other.   The tension holding means includes a flexible tension member and a holding member that holds the tension member in a relaxed state. The holding member includes a wire fixing portion and a building-side attachment portion. The tension relaxation device according to claim 1, wherein the tension relaxation device is configured not to hold the tension member in a relaxed state when a predetermined tension is applied therebetween.   The tension relaxation device according to claim 2, wherein the tension member is made of an insulating material.   The tension relaxation device according to claim 3, wherein the holding member is made of an insulating material.

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