Jig and installation method

Abstract

The purpose of the present invention is to provide a jig and a laying method which make it possible to lay branch lines that can avoid contact with houses and passersby and that can resolve the unbalanced load of electric poles erected in narrow places.　By connecting a first member of a jig of the present invention and the tip of an electric pole by using an upper branch line and connecting a second member of the jig and the ground by using a lower branch line perpendicular to the ground, it is possible to lay in narrow places while resolving the unbalanced load of electric poles by ensuring a mounting angle of the upper branch line with respect to the electric pole. Also, by ensuring an optimal separation distance between the electric pole and the lower branch line, it is possible to reduce contact risk to houses and passersby.

Description

[Technical Field]

[0001] The present disclosure relates to a jig to be attached to a utility pole and a method for installing the utility pole. [Background technology]

[0002] Conventionally, existing utility poles have a hollow interior and a tapered shape in the longitudinal direction, are made of metal or concrete materials, and are installed for the purpose of laying cables in the air.

[0003] For these utility poles, there is a construction method in which a guy wire made of steel stranded wire or the like is lowered from a specific point below the top of the utility pole onto the ground a certain distance away from the pole, and the guy wire is fixed to the ground with an anchor or the like, so that the guy wire bears the reaction force of the unbalanced load caused by laying the cable, etc., thereby eliminating the unbalanced load (see, for example, non-patent document 1). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Nippon Telegraph and Telephone Public Corporation Publishing, "City Line Construction Methods," 4.6 Guy Lines and Supports, 4.6.1 Overview Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned construction method for eliminating unbalanced loads has the following problems.

[0006] When erecting a utility pole, anchors 16 or the like may be laid to secure guy wire 15 to the ground 50. In this case, there is a limit to the distance (hereinafter referred to as "root spacing") from the ground level of utility pole 10 to anchor 16. Therefore, when laying guy wire 15 in a narrow location where the laying range is limited by houses 20 or the like, as shown in Figure 1, a first problem arises in that measures are required to avoid contact with houses 20 or pedestrians 5.

[0007] Furthermore, narrowing the root gap when installing a guy wire on a utility pole that requires it presents a second problem in that the attachment angle of the guy wire to the utility pole is reduced, making it difficult to fully achieve the effect of the guy wire in eliminating unbalanced loads.

[0008] In the past, the problem of unbalanced loads on utility poles constructed in such narrow spaces has been solved by replacing them with stronger poles (self-supporting poles) that do not require guy wires. However, self-supporting poles have a higher unit price than regular utility poles, resulting in high construction costs. Furthermore, in narrow spaces, heavy machinery may not be able to enter, and pole erection work often has to be done manually, which poses the problem of having to be careful of accidents such as collisions and damage to surrounding houses.

[0009] Therefore, in order to solve the above problems, the present invention aims to provide a jig and installation method that can lay guy wires that can avoid contact with houses and pedestrians and eliminate unbalanced loads on utility poles erected in narrow locations. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the laying method of the present invention involves fixing to a utility pole a jig having at its tip a member for fixing the branch wire from the top of the utility pole (hereinafter referred to as the upper branch wire) and a member for fixing the branch wire on the ground side (hereinafter referred to as the lower branch wire).

[0011] Specifically, the jig according to the present invention is a rod-shaped jig having one end attached to the surface of the utility pole so as to be perpendicular to the utility pole, At the other end, it is characterized by having a first member that holds an upper branch wire that connects to the top of the utility pole, and a second member that holds a lower branch wire that is parallel to the utility pole and connects to the ground.

[0012] The laying method according to the present invention further comprises: Attaching one end of a rod-shaped jig to a surface of the utility pole so that the jig is perpendicular to the utility pole; Connecting the other end of the jig to the top of the utility pole with an upper guy wire; and connecting the other end of the jig to the ground with the lower branch wire so that the lower branch wire is parallel to the utility pole; Do the following.

[0013] By connecting the first component of the jig to the tip of the utility pole with an upper support wire and the second component of the jig to the ground with a lower support wire that is perpendicular to the ground, it is possible to install the cable in narrow spaces while ensuring the attachment angle of the upper support wire to the utility pole and eliminating unbalanced loads on the utility pole.In addition, by ensuring an optimal distance between the utility pole and the lower support wire, the risk of contact with houses or pedestrians can be reduced.

[0014] Furthermore, the jig according to the present invention further includes an extension mechanism that allows the length in the longitudinal direction to be changed.

[0015] The laying method according to the present invention comprises the steps of: calculating an unbalanced load on the utility pole; Obtaining a relationship between the longitudinal length of the jig and the load amount generated by the upper support line; finding the length of the fixture that eliminates the unbalanced load from the relationship; and Setting the length of the jig attached to the utility pole to the length found from the relationship. Further implementation will be carried out.

[0016] By installing a variable mechanism that can adjust the length of the jig, construction can be carried out in narrow spaces more flexibly to suit the surrounding environment. By eliminating unbalanced loads in narrow spaces that were previously not possible, it is possible to achieve long-term safe use of utility poles and reduce reconstruction costs.

[0017] The above inventions can be combined as much as possible. [Effects of the Invention]

[0018] The present invention can provide a jig and a laying method that can lay guy wires that can avoid contact with houses and pedestrians and eliminate unbalanced loads on utility poles erected in narrow locations. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram illustrating the installation of a branch line in a narrow location where the installation range is limited by houses or the like, and is a diagram illustrating the problem of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a jig according to the present invention. [Figure 3] FIG. 2 is a diagram illustrating a jig according to the present invention. [Figure 4] 3 is a flowchart illustrating a laying method according to the present invention. [Figure 5] 10A and 10B are diagrams illustrating the effect of the jig according to the present invention. [Figure 6] 10A and 10B are diagrams illustrating the effect of the jig according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The following description of the preferred embodiments of the present invention will be given with reference to the accompanying drawings. The preferred embodiments described below are examples of the present invention, and the present invention is not limited to the preferred embodiments. In this specification and the drawings, components having the same reference numerals are intended to represent the same components.

[0021] (Embodiment 1) 2 and 3 are diagrams illustrating the jig 30 of this embodiment. The jig 30 is a rod-shaped jig having one end 30a attached to the surface of the utility pole 10 so as to be perpendicular to the utility pole 10. The other end 30b is characterized by having a first member 31 that holds an upper branch wire 15-1 that connects to the top 10a of the utility pole 10, and a second member 32 that holds a lower branch wire 15-2 that connects to the ground 50 parallel to the utility pole 10.

[0022] The jig 30 has a first member 31 for fixing the upper branch wire 15-1 at its other end 30b, and a second member 32 for fixing the lower branch wire 15-2. The jig 30 is made of a metal material or the like, and has a round, square, or other columnar or cylindrical shape.

[0023] One end 30a of the jig 30 is fixed to the surface of the utility pole 10 so that its central axis is perpendicular to the central axis of the utility pole 10. A band 33 is preferably used to fix the jig 30. An upper support wire 15-1 connects the first member 31 to the top 10a (wire-interconnecting portion) of the utility pole 10, and a lower support wire 15-2 that is perpendicular to the ground 50 (parallel to the utility pole 10) connects the second member 32 to the ground 50. By using the jig 30 to lay the support wire, it is possible to lay the support wire in a narrow space while ensuring the attachment angle θ of the upper support wire 15-1 to the utility pole 10 and eliminating the unbalanced load on the utility pole 10. Furthermore, by appropriately separating the utility pole 10 and the lower support wire 15-2, it is possible to ensure space A for pedestrians to walk and reduce the risk B of contact with a house 20.

[0024] The jig 30 further includes an extension mechanism 34 that can change its length in the longitudinal direction. The extension mechanism 34, which can adjust the length of the jig 30, allows for more flexible construction in narrow spaces that are suited to the surrounding environment, and by eliminating unbalanced loads in narrow spaces that were previously not possible, it is possible to achieve long-term safe use of utility poles and reduce reconstruction costs.

[0025] (Embodiment 2) FIG. 4 is a flowchart illustrating the steps of the laying method of this embodiment. Attaching one end 30a of the rod-shaped jig 30 to the surface of the utility pole 10 so that the jig 30 is perpendicular to the utility pole 10 (step S01); Connecting the other end 30b of the jig 30 to the top portion 10a of the utility pole 10 with the upper support wire 15-1 (step S02); Connecting the other end 30b of the jig 30 to the ground 50 with the lower branch wire 15-2 so that the lower branch wire 15-2 is parallel to the utility pole 10 (steps S03 and S04). Do the following.

[0026] Step S01: One end 30a of the jig 30 is fixed to the utility pole 10 at a specific height from the ground. Step S02: The upper support wire 15-1 is stretched from the top portion 10a (wire bridging portion: metal fittings that hold cables, etc.) of the utility pole 10 to the other end 30b of the jig 30, and the jig 30 is fixed horizontally to the ground 50. Step S03: The anchors 16 and the like are installed on the ground 50 around the utility pole 10. Step S04: A lower support wire 15-2 is stretched perpendicularly from the other end 30b of the installed jig 30 to the ground surface 50 and fixed to an anchor 16 or the like. Step S05: If the support wires connected to the jig 30 become loose, the effect of eliminating the unbalanced load will be reduced, so the tension of the support wires is adjusted. This allows the reaction force of the unbalanced load to be shared and eliminated.

[0027] Next, step S06 will be described. The length of the jig 30 is adjusted depending on the magnitude of the unbalanced load acting on the utility pole. Step S06 is performed in the following procedure. (Step 1) Calculate the unbalanced load on the utility pole 10; (Step 2) Obtain the relationship between the longitudinal length of the jig 30 and the load amount generated by the upper support wire 15-1. (Step 3) Finding the length of the jig 30 that eliminates the unbalanced load from the relationship; and (Step 4) Set the length of the jig 30 attached to the utility pole 10 to the length found from the relationship.

[0028] First, step 1 will be explained. The tension T of the cable laid on the utility pole 10 when there is no wind is expressed by the following formula (1).

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[0029] When there is wind, the unbalanced load that power and communication lines place on utility poles increases compared to when there is no wind. The load that occurs on power and communication lines due to wind is expressed by the following equation (2).

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[0030] The cable weight per unit length W1 (N / m) taking into account wind pressure load is given by the following formula (3).

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[0031] Next, we will explain step 2. 5 is a diagram illustrating the forces generated in utility pole 10 on which jig 30 is installed. At this time, the force exerted on utility pole 10 by cable 11 laid on utility pole 10 becomes unbalanced load F. Let h [m] be the height from ground 50 of the attachment position of jig 30, H [m] be the height from ground 50 of the attachment position of upper support wire 15-1 to utility pole 10, θ [°] be the attachment angle of upper support wire 15-1, and a [m] be the length of jig 30.

[0032] In this case, assuming that the upper support wire 15-1 is tensioned with a tension of F [kN], the load P [kN] that can be borne by the upper support wire 15-1 can be expressed by the following equation (5). [Number 5] P=Fsinθ (5) The relationship between the angle θ and the length a is given by the following equation (6). [Number 6] a=(Hh)tanθ (6) For example, when jig 30 is attached at a position of H=6m, h=3m and the tension of the guy wire is F=10kN, the relationship between the length a [m] of jig 30 and the load capacity P [kN] that the guy wire can support is as shown in Figure 6.

[0033] 6 is a graph illustrating the relationship between the length a of the jig 30 on the horizontal axis and the load P that can be shared by the upper support wire 15-1 on the vertical axis when the support wire angle θ is changed from 0° to 60°. As shown in the graph, a change in the length a of the jig 30 of just 0.1 m results in a difference of 0.1 to 0.35 kN in the load P that can be secured by the upper support wire 15-1.

[0034] Next, we will explain step 3. The load on a utility pole depends on the type of utility pole, but is a minimum of about 2 kN. As shown in the relationship in Figure 6, the load varies depending on the length a of the jig 30, so if the length a of the jig 30 is not adjusted, an unbalanced load of about 10% will remain. Therefore, based on the relationship in Figure 6, we find the length a of the jig 30 that generates a load P that cancels out the unbalanced load T calculated in step 1.

[0035] Finally, perform step 4. Adjust the extension mechanism 34 of the jig 30 so that the length becomes the length a found in step 3.

[0036] As described above, the telescopic mechanism 34 needs to be able to adjust the length a of the jig 30 on the order of 10 cm in order to eliminate an unbalanced load of around 10%. Thus, in order to appropriately eliminate the unbalanced load T occurring on the utility pole 10, the jig 30 needs to have the ability to flexibly adjust the length a. [Explanation of symbols]

[0037] 10: Electric pole 10a: Top 15: Branch line 15-1: Upper branch line 15-2: Lower branch line 16: Anka 20: House 30: Jig 30a: one end 30b: other end 31: First member 32: Second member 33: Band 34: Telescopic mechanism 50: Ground

Claims

1. A rod-shaped jig having one end attached to the surface of the utility pole so as to be perpendicular to the utility pole, A jig characterized by having at its other end a first member that holds an upper branch wire that connects to the top of the utility pole, a second member that holds a lower branch wire that connects to the ground parallel to the utility pole, and an extension mechanism that allows the longitudinal length to be changed.

2. Attaching one end of a rod-shaped jig to a surface of the utility pole so that the jig is perpendicular to the utility pole; Connecting the other end of the jig to the top of the utility pole with an upper guy wire; and connecting the other end of the jig to the ground with the lower branch wire so that the lower branch wire is parallel to the utility pole; A laying method for performing The jig has an extension mechanism that changes the length in the longitudinal direction, calculating an unbalanced load on the utility pole; Obtaining a relationship between the longitudinal length of the jig and the load amount generated by the upper support line; finding the length of the fixture that eliminates the unbalanced load from the relationship; and Using the telescopic mechanism, the length of the jig attached to the utility pole is set to the length found from the relationship. The laying method further comprises the steps of:

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