Overhead ground wire installation structure and transmission tower

Abstract

To provide an overhead ground wire attachment structure capable of being constructed on the basis of a production standard for a power transmission angle steel tower and retarding the deterioration of the top part of a pointed top part of a power transmission line tower.SOLUTION: An attachment structure for an overhead ground wire 14 provided on the top part of a pointed top part P1 of a power transmission line tower 2 is an overhead ground wire attachment structure 1A that is provided with a top plate 7 obtained by bending a flat plate into a U-shaped cross section and comprising an upper part 7a that is arranged on a vertical upper end surface T side of a main column material 2c forming the pointed top part P1 and a side part 7b that extends to side edges S across the upper part 7a and is arranged on a side surface U of the power transmission line tower 2, a side plate 9 that is provided on the side surface U of the power transmission line tower 2 on which the side part 7b of the top plate 7 is not arranged in the pointed top part P1, and a tension plate 13 attached to the upper part 7a of the top plate 7 and to which the overhead ground wire 14 is connected, and the upper part 7a of the top plate 7 comprises a notch 8 for ventilation and water conduction in an area not overlapping with the tension plate 13 in a plan view.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an overhead ground wire installation structure that can be constructed in accordance with the production standards for power transmission angle steel towers and that can delay deterioration of the topmost part of the pointed top of the power transmission tower, and to a power transmission tower equipped with the same.

[0002] First, a transmission tower equipped with a conventional overhead ground wire installation structure and problems that arise in such a transmission tower will be described with reference to Figs. 4 to 7. First, an overview of the structure of a transmission tower will be described with reference to FIG. FIG. 4(a) is a side view of the transmission tower, and (b) is a perspective view of the upper part of the transmission tower. As shown in Figures 4(a) and (b), a transmission tower 2' is generally made up of angle steel members, and is constructed by, for example, adding four main pillar members 2a (double line parts in Figure 4) and web members 2b (diagonal members 2b1 and horizontal members 2b2; dotted line parts in Figure 4) vertically upward. In such a transmission tower 2', as shown in Figures 4(a) and (b), a power line cross arm 3 (solid line part in Figure 4) protrudes horizontally from the side of the tower, and a power line 4 is attached to the tip of this power line cross arm 3 via an insulator 6. Furthermore, the above-mentioned transmission tower 2' is equipped with an overhead ground wire 14 for the purpose of lightning protection in addition to the power line 4. This overhead ground wire 14 differs depending on the voltage class of the power line 4, but for example, as shown in Figures 4(a) and (b), when there is a single overhead ground wire 14, the transmission tower 2' generally has a pointed-top structure with a pointed top P1 on the upper side of the leg P3 and the body P2.

[0003] Next, a conventional overhead ground wire installation structure provided at the top of the pointed apex P1 will be described with reference to Figs. Fig. 5 is a perspective view of a conventional overhead ground wire installation structure installed at the top of the pointed top of a transmission tower. Fig. 6(a) is a development view of a top plate and a plan view of a side plate constituting the conventional overhead ground wire installation structure, and Fig. 6(b) is a side view of the top plate and side plate constituting the conventional overhead ground wire installation structure installed at the top of the pointed top of a transmission tower. The same parts as those shown in Fig. 4 are given the same reference numerals, and the description of their configuration is omitted. The overhead ground wire installation structure 20 of the prior art is mainly composed of an overhead ground wire 14 installed between the transmission tower 2' shown in Figure 5 and another transmission tower (not shown) that is arranged isolated from this transmission tower 2', a tension plate 13 that connects the ends of this overhead ground wire 14, and a fixing means for fixing this tension plate 13 to the top of the pointed top P1 of the transmission tower 2'.

[0004] The fixing means of the tension plate 13 as described above includes a top plate 21 made of a rectangular flat plate material as shown in FIG. 6(a), and two trapezoidal side plates 22 also as shown in FIG. 6(a). Furthermore, the top plate 21 is bent into a U-shape in cross section and arranged to cover the upper ends T of the four main pillar materials 2c located at the top of the pointed top P1 of the transmission tower 2' (see Figure 6(b)), and the two side plates 22 are each arranged at the top of the pointed top P1 on the side U on the side where the side portion 21b of the top plate 21 is not arranged (see Figures 5 and 6(b)), and both the top plate 21 and the side plates 22 are fixed to the main pillar materials 2c by bolts 11 and nuts 12 (see Figure 5). In other words, at the top of the pointed top P1 of the transmission tower 2', a container-shaped object consisting of a top plate 21 and a side plate 22 is fixed to the upper end of the main pillar material 2c with the top part 21a of the top plate 21 facing vertically upward. A tension plate 13 is fixed to the center of the upper surface of the top portion 21a constituting the top plate 21 as described above by means of a bolt 11 and a nut 12 (see FIG. 5). Furthermore, in the overhead ground wire installation structure 20 according to the prior art, as shown in Fig. 5, ends of the overhead ground wire 14 are fixed via clamps 15 to connecting members 17 arranged on the left and right sides of the end 13a of the tension plate 13. Also, the electrical connection between the overhead ground wires 14 is achieved by fixing both ends of a single jumper wire 16 with the clamps 15, respectively. In the overhead ground wire installation structure 20 according to the prior art, as shown in FIG. 5, in order to prevent the excess portion 16a of the jumper wire 16 from swaying in the wind, the central portion of the length is fixed to the tension plate 13 by a suspension clamp 18 provided on the tension plate 13, and the excess portion 16a is pressed and deformed so as to be bent into an approximately M shape. Incidentally, the overhead ground wire installation structure 20 according to the prior art shown in Figs. 5 and 6(a) is constructed based on the manufacturing standards for electric power transmission angle steel towers.

[0005] Here, the problems with the overhead ground wire installation structure 20 according to the conventional technology will be described with reference to Figs. 5, 6(b) and 7. FIG. 7 is an image of a conventional overhead ground wire installation structure viewed from the inside of the pointed top. Although the overhead ground wire installation structure 20 according to the prior art can be constructed based on the standards for manufacturing electric power transmission angle steel towers, as is clear from Figures 5 and 6(b), the top of the pointed apex P1 is in a closed state. In this case, moisture tends to accumulate on the inside of the top of the pointed apex P1, and because it is not exposed to rainwater, impurities (corrosion-promoting substances) such as salt adhering to the inside (backside) of the top plate 21 and side plate 22 cannot be washed away by rainwater. For this reason, as shown in Figure 7, there is a problem that rusting, and the associated corrosion and deterioration of the metal, tends to occur easily on the inside of the top of the pointed apex P1. Furthermore, if corrosion occurs and deteriorates in the top plate 21 and side plate 22 of the overhead ground wire installation structure 20 relating to the conventional technology as shown in Figures 5 and 6(b) above, as well as the main pillar material 2c to which they are attached, the overhead ground wire 14 cannot be safely installed, which could cause a disruption to the transmission of electricity through the power line 4 shown in Figure 4 above. In order to address the above-mentioned problems, the applicant of the present invention has previously filed prior applications such as those shown below.

[0006] Patent document 1 discloses an invention titled “Rust prevention structure for the top of a transmission tower” that relates to a rust prevention structure for the top of a transmission tower that can effectively prevent rust that tends to occur on the inner surface of the top plate that covers the top of the transmission tower. The rust-proofing structure for the top of a transmission tower disclosed in Patent Document 1, explained using the symbols shown in Figure 3 in the document, is a transmission tower having a top plate 30 that is fixed in a state covering the uppermost ends of each main pillar material 15 located at the uppermost part, and the top plate comprises a top plate 31 that covers part of the approximately rectangular upper open surface 17 formed between the uppermost ends of each of the uppermost main pillar materials, and side plates 35 that are fixed to each of the uppermost main pillar materials with bolts and nuts to cover the four open side surfaces formed between each of the uppermost main pillar materials, the top plate being a narrow member that is arranged across two opposing sides of the upper open surface and is integrated with two side plates 35a, 35b that correspond to the two sides, and ventilation openings 40 are formed between both widthwise ends of the top plate and the other two side plates 35c, 35d. According to the invention disclosed in Patent Document 1 as described above, it is possible to effectively prevent impurities such as salt from accumulating on the concave underside of the top plate, which is fixed to the top of a transmission tower and installs a tension plate supporting an overhead ground wire, and causing the inside to rust.

[0007] Patent Document 2 discloses an invention titled “Transmission Tower Top Structure” that relates to a transmission tower top structure that reinforces the top of the transmission tower while fixing the overhead ground wire installed between the transmission towers. The transmission tower top structure disclosed in Patent Document 2, when explained using the same symbols as shown in Figure 1 in the document, is characterized in that the top 100 of the transmission tower has an open section 18, which is an open-top structure in which the entire top surface is open, and the sides of the top 100 are provided with a pair of opposing upper side plates 12-1 and 12-2 and lower side plates 16-1 and 16-2 displaced downwardly of the pair of upper side plates 12-1 and 12-2, and the top plate 14 is erected in a state in which the open section 18 is secured between the pair of upper side plates 12-1 and 12-2. According to the invention disclosed in Patent Document 2 as described above, air flows in from the vertical and horizontal directions of the top 100, quickly drying water droplets adhering to the components provided on the top 100 and suppressing the generation of moisture, thereby preventing rusting of the lower part of the top plate 14 and suppressing deterioration of the transmission tower top structure 10. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2013-141381 A [Patent Document 2] JP 2012-50214 A Summary of the Invention [Problem to be solved by the invention]

[0009] According to each of the inventions disclosed in the above-mentioned Patent Documents 1 and 2, it is possible to improve the air and water permeability in the upper part of the tower, thereby suppressing the formation of rust in the upper part of the tower and the accompanying corrosion and deterioration of the metal. On the other hand, neither of the inventions disclosed in Patent Documents 1 and 2 is based on the standard for manufacturing steel angle towers for power transmission. In other words, since it is not possible to fix the overhead ground wire 14 to the top of the peak of the power transmission tower using a tension plate 13, even if they are recognized as inventions, they have the problem that they cannot be actually constructed on site from the viewpoint of safety standards, etc. The reason for this is as follows.

[0010] Paragraph 0015 of the specification of Patent Document 1 states, "If the top plate 31 is configured to have a narrow shape, it will not be possible to fix a large tension plate 120 as shown in Figure 7 (the same as the tension plate 13 shown in Figure 5 above) onto the top plate." Therefore, in the case of the invention disclosed in Patent Document 1, it is not possible to fix the overhead ground wire 14 to the top of the pointed top of the transmission tower using a tension plate 13 as shown in FIG. Furthermore, in the case of adopting the top structure of the steel tower disclosed in Patent Document 2, and attempting to attach an overhead ground wire to this top structure using the tension plate 13 shown in Fig. 5 above, it is considered necessary to arrange the tension plate 13 so as to intersect with the longitudinal direction of the top plate shown in Fig. 1(b) and Fig. 2 to Fig. 5 of Patent Document 2. In this case, the overlapping area of ​​the top plate and tension plate 13 of Patent Document 2 becomes narrow, and they cannot be firmly fixed with bolts and nuts as shown in Fig. 5 above. In other words, in the case of the invention disclosed in Patent Document 2, it is also not possible to fix the overhead ground wire 14 to the top of the pointed top of the transmission tower using a tension plate 13 as shown in FIG.

[0011] The present invention has been made in response to the above-mentioned conventional circumstances, and its purpose is to provide an overhead ground wire installation structure that can be constructed in accordance with the standards for manufacturing transmission angle steel towers and that can delay deterioration of the uppermost part of the pointed top of the transmission tower, and a transmission tower equipped with the same. [Means for solving the problem]

[0012] The overhead ground wire installation structure, which is the first invention for solving the above-mentioned problems, is an installation structure for an overhead ground wire installed at the top of the pointed top of a transmission tower, and comprises a top plate made by bending a flat plate material into a U-shaped cross section, having a top portion arranged on the vertically upper end face side of the main pillar material that constitutes the pointed top, and side portions extended to each side edge across the top portion and arranged on the side of the transmission tower, side plates provided on each side of the pointed top of the transmission tower where the side portion of the top plate is not located, and a tension plate attached to the top of the top plate and to which the overhead ground wire is connected, and is characterized in that the top portion of the top plate has notches for ventilation and water passage in an area that does not overlap with the tension plate when viewed in a plan view. In the first invention having the above configuration, the top of the top plate acts as a support plate when fixing a tension plate to the top of the pointed top of the transmission tower, and the side of the top plate also acts as a support plate for attaching the top of the top plate to the main pillar material that constitutes the pointed top. Furthermore, the side plate has the effect of connecting and integrating the adjacent main pillar members at the top of the pointed apex, which are the main pillar members on the side to which the side of the top plate is not fixed, thereby increasing the rigidity and strength of the top of the pointed apex. In addition, the tension plate has the effect of indirectly fixing the end of the overhead ground wire to the top of the pointed top of the transmission tower, by connecting the end of the overhead ground wire and fixing its body integrally to the top of the top plate with fasteners such as bolts and nuts. Furthermore, the notch formed in the top portion of the top plate has the effect of improving air and water permeability between the inside and outside at the uppermost portion of the pointed apex. In this case, moisture is less likely to accumulate at the top of the pointed top, and impurities (corrosion-promoting substances) such as salt that have adhered to the inside of the top can be efficiently washed away by rainwater, which has the effect of effectively suppressing rust formation on the inside of the top of the pointed top of the transmission tower, as well as the associated corrosion and deterioration of the metal. In addition, in the first invention, the overhead ground wire can be fixed to the top of the pointed top of the transmission tower in accordance with the standards for manufacturing steel angle towers for power transmission. In other words, the first invention satisfies the current standards and can be implemented on site.

[0013] The overhead ground wire installation structure, which is the second invention, is the first invention described above, characterized in that when the top of the top plate is viewed in a plane, the width W1 of the top and the width W2 of the tension plate are the same. The second invention having the above configuration has the same effect as the first invention. Furthermore, in the second invention, when the top of the top plate is viewed in plan, the width W1 of the top is set to be the same as the width W2 of the tension plate, thereby maximizing the area of ​​the cutout in the top while ensuring a sufficient connection area with the tension plate in the top. In this case, the air and water permeability at the notch (opening) formed in the top portion of the top plate can be made extremely good.

[0014] The overhead ground wire installation structure, which is the third invention, is the first invention described above, characterized in that the top portion of the top plate has a plurality of holes penetrating the thickness direction of the top portion instead of notches. The third invention having the above configuration has the same effect as the first invention. Furthermore, in the third invention, the multiple holes drilled in the area that does not overlap with the tension plate when the top part is viewed in plan have the effect of improving the air and water permeability inside and outside the top part of the pointed apex, similar to the notch.

[0015] The overhead ground wire installation structure, which is a fourth invention, is any of the first to third inventions described above, and is characterized in that when viewed from the side with a side plate attached to the pointed top, there is a gap between the top of the top plate and the upper edge of the side plate. The fourth invention having the above configuration has the same effect as each of the first to third inventions. Also, in the fourth invention, the top of the pointed apex can form a gap on the side panel side in addition to the top surface side, which improves air and water permeability inside and outside. Therefore, the third invention has the effect of more reliably suppressing rust formation on the inside of the topmost part of the pointed top of the transmission tower, as well as the accompanying progression of metal corrosion and deterioration.

[0016] The fifth invention is a transmission tower characterized in that it has a pointed top having an overhead ground wire attachment structure according to any one of the first to fourth inventions described above. The fifth invention specifies as an invention a transmission tower having a pointed top having an overhead ground wire installation structure which is any one of the first to fourth inventions described above, and its function is the same as that of each of the first to fourth inventions described above. Effect of the Invention

[0017] According to the first invention as described above, it is possible to reliably delay the rusting of the parts constituting the uppermost part at the pointed top of the transmission tower, as well as the progression of the associated metal corrosion and deterioration. In this case, the durability of the transmission tower having the pointed top can be improved. Also, according to the first invention, the costs required for maintenance and rebuilding can be reduced compared to the case of using a transmission tower equipped with the overhead ground wire installation structure 20 as shown in Fig. 5 and Fig. 6(b). In addition, the first invention can be constructed based on the standard for constructing pointed-top transmission towers, which is the standard for constructing pointed-top transmission towers. Therefore, unlike the inventions disclosed in Patent Documents 1 and 2, the first invention can be immediately implemented on-site without the need for separate inspections or tests to confirm whether a transmission tower equipped with these inventions meets the safety standards. Therefore, according to the first invention, it is possible to provide an overhead ground wire installation structure that can effectively delay deterioration of the top part of the pointed top of a transmission tower and meets the current manufacturing standards for transmission angle steel towers.

[0018] The second aspect of the invention has the same effects as those of the first aspect of the invention. Furthermore, according to the second aspect of the invention, the area of ​​the notch formed in the top portion of the top plate can be maximized. Therefore, according to the second aspect of the invention, the effect of improving the air and water permeability is maximized at the topmost part of the pointed apex. Therefore, according to the second invention, it is possible to provide a transmission tower having superior durability at the top part of the pointed top compared to the first invention.

[0019] The third invention has the same effect as the first invention. Furthermore, according to the third invention, as a configuration corresponding to the notch in the first invention, a plurality of holes are provided through the top part of the top plate in the thickness direction, so that the missing area of ​​the top part can be relatively smaller than that of the first invention. Therefore, according to the third invention, it is possible to provide an overhead ground wire installation structure having a top plate with relatively high strength compared to the above-mentioned first invention. Therefore, according to the third invention, when the installation location of the transmission tower is such that the strength of the top plate supporting the tension plate is required due to reasons such as constant strong winds, it is possible to provide an overhead ground wire installation structure that meets this requirement without compromising the air and water permeability at the top of the pointed top.

[0020] The fourth invention has the same effects as the first to third inventions described above. Furthermore, according to the fourth invention, the air and water permeability can be improved on the side of the top of the pointed apex, i.e., on the side where the side plate is attached. This makes it possible to more reliably delay the formation of rust on the inside of the top of the pointed tip, and the accompanying corrosion and deterioration of the metal, compared to when the top of the pointed tip only has a notch or multiple through holes to improve air and water permeability inside and outside the tip. Therefore, according to the fourth invention, it is possible to provide an overhead ground wire installation structure that is more durable than each of the first to third inventions. As a result, by providing the fourth invention at the top of the pointed top of the transmission tower, the durability of the transmission tower itself can be improved.

[0021] The fifth invention specifies a transmission tower equipped with an overhead ground wire installation structure which is each of the first to fourth inventions described above as a product invention. Therefore, the fifth aspect of the invention has the same effects as the first to fourth aspects of the invention. [Brief description of the drawings]

[0022] [Figure 1] 1 is a perspective view of an overhead ground wire installation structure according to an embodiment of the present invention; [Diagram 2] FIG. 1A is an exploded view of a top plate and a plan view of a side plate that constitute the overhead ground wire installation structure of an embodiment of the present invention, and FIG. 1B is a side view of the top plate and side plate that constitute the overhead ground wire installation structure of an embodiment of the present invention installed at the top of the pointed top of a transmission tower. [Diagram 3] FIG. 1A is an exploded view of a top plate and a plan view of a side plate that constitute an overhead ground wire installation structure relating to a modified example of this embodiment, and FIG. 1B is a side view of the top plate and side plate that constitute an overhead ground wire installation structure relating to a modified example of this embodiment attached to the top of the pointed top of a transmission tower. [Figure 4] (a) is a side view of the transmission tower, and (b) is a perspective view of the top of the transmission tower. [Diagram 5] FIG. 1 is a perspective view of a conventional overhead ground wire installation structure provided at the top of a pointed top of a transmission tower. [Figure 6] FIG. 1A is an exploded view of a top plate and a plan view of a side plate that constitute an overhead ground wire installation structure according to the prior art, and FIG. 1B is a side view of the top plate and side plate that constitute an overhead ground wire installation structure according to the prior art installed at the top of the pointed top of a transmission tower. [Figure 7] 1 is an image of a conventional overhead ground wire installation structure viewed from the inside of the pointed top. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] An overhead ground wire installation structure and a transmission tower equipped with the same according to an embodiment of the present invention will be described with reference to Figs. 1 to 3.

[0024] [1-1: Basic configuration of the present invention] The overhead ground wire installation structure according to the embodiment of the present invention is an alternative structure to the overhead ground wire installation structure 20 according to the prior art that is provided at the top of the pointed top portion P1 of the transmission tower 2' shown in FIG. Therefore, the transmission tower according to this embodiment has the same structure (configuration) as the transmission tower 2' shown in Fig. 4 except for the overhead ground wire installation structure 20 according to the conventional technology. For this reason, detailed description of the configuration other than the overhead ground wire installation structure in the transmission tower according to this embodiment will be omitted here. First, an overhead ground wire installation structure according to an embodiment of the present invention will be described with reference to Figs. FIG. 1 is a perspective view of an overhead ground wire installation structure according to an embodiment of the present invention. FIG. 2(a) is a development view of a top plate and a plan view of a side plate constituting the overhead ground wire installation structure according to an embodiment of the present invention, and FIG. 2(b) is a side view of the top plate and side plate constituting the overhead ground wire installation structure according to an embodiment of the present invention, attached to the topmost part of the pointed top of a transmission tower. The same parts as those shown in FIG. 4 to FIG. 6 are given the same reference numerals, and the description of their configurations is omitted. In FIG. 2(a), the outlines of the main pillar material 2c and the side plate 9 are shown by dashed lines so that the positional relationship between the main pillar material 2c constituting the pointed top P1 of the transmission tower 2 and the top plate 7 can be easily understood.

[0025] As shown in FIG. 1, the overhead ground wire installation structure 1A of this embodiment is provided at the top of the pointed top portion P1 of a transmission tower 2, and is a top structure for tying down the end of an overhead ground wire 14. The overhead ground wire installation structure 1A of this embodiment mainly comprises a top plate 7 provided on the vertical upper end T side of the main pillar material 2c that constitutes the pointed top P1, two side plates 9 provided on the side U of the pointed top P1 on the side on which the top plate 7 is not installed, and a tension plate 13 attached to the uppermost surface (ceiling portion 7a) of the top plate 7 and holding the end of the overhead ground wire 14. Furthermore, the top plate 7 in the overhead ground wire installation structure 1A of this embodiment as described above is formed by bending a flat plate material such as that shown in Figure 2(a) into a U-shaped cross section as shown in Figures 1 and 2(b). The top plate 7 as described above comprises a top portion 7a arranged on the vertical upper end face T side of the main pillar material 2c that constitutes the pointed top P1 of the transmission tower 2, and side portions 7b extending to each side edge S on either side of the top portion 7a and arranged on the side surface U of the transmission tower 2, and the top portion 7a has a pair of notches 8 on the edge other than the side edge S. More specifically, when the overhead ground wire installation structure 1A of this embodiment is viewed in a plan view with the top plate 7 as described above attached to the top of the pointed top of the transmission tower 2, the pair of notches 8, 8 are formed in an area that does not overlap with the tension plate 13 attached to the top portion 7a of the top plate 7, as shown in Figure 1. Furthermore, both the top plate 7 and the side plate 9 as described above are provided with bolt insertion holes 10 for fastening to the pointed top portion P1 of the transmission tower 2 using bolts 11 and nuts 12 (see FIG. 2(a)).

[0026] Furthermore, in the overhead ground wire installation structure 1A according to this embodiment, a tension plate 13 is fixed to the center of the upper surface of the top portion 7a constituting the top plate 7 by a bolt 11 and a nut 12. In the overhead ground wire installation structure 1A according to this embodiment, ends of the overhead ground wire 14 are fixed via clamps 15 to the connection members 17 arranged on the left and right sides of the end 13a of the tension plate 13. The overhead ground wires 14 are electrically connected to each other by fixing both ends of a single jumper wire 16 with the clamps 15, respectively. In addition, in the overhead ground wire installation structure 1A of this embodiment, in order to prevent the excess portion 16a of the jumper wire 16 from swaying in the wind, the central portion of its length is fixed to the tension plate 13 by a suspension clamp 18 provided on the tension plate 13, and the excess portion 16a is pressed and deformed to be bent into an approximately M shape. The fixing structure of the overhead ground wire 14 to the top portion 7a of the top plate 7 in the overhead ground wire installation structure 1A of this embodiment shown in Figure 1 is the same as the fixing structure of the overhead ground wire 14 to the top portion 21a of the top plate 21 in the overhead ground wire installation structure 20 of the conventional technology shown in Figure 5 above.

[0027] [1-2: About the action and effect of the present invention] In the overhead ground wire installation structure 1A of this embodiment shown in Figures 1 and 2, similar to the overhead ground wire installation structure 20 of the prior art shown in Figure 5, a tension plate 13 is fixed to the top plate 7 and the overhead ground wire 14 is fastened to this tension plate 13, thereby enabling the overhead ground wire 14 to be fixed to the transmission tower 2. In addition, the jumper wire 16 that electrically connects the overhead ground wires 14 to each other can also be attached to the top plate 7 using a suspension clamp 18, similar to the overhead ground wire attachment structure 20 of the prior art. Therefore, the overhead ground wire installation structure 1A of this embodiment, like the overhead ground wire installation structure 20 of the conventional technology, can be constructed based on the transmission angle steel tower manufacturing standards, so there is no problem in implementing it on site. On the other hand, in the case of the inventions disclosed in the above-mentioned Patent Documents 1 and 2, when fixing the overhead ground wire 14 to the top of the pointed top of the transmission tower, it is not possible to use the tension plate 13, which is a fixing structure based on the manufacturing standards for transmission angle steel towers. For this reason, if one were to actually put the inventions disclosed in Patent Documents 1 and 2 into practice on-site, it would be necessary to carry out inspections and tests to confirm their safety, etc., and it would be necessary to establish new construction standards, and so they could not be put into practice immediately. Therefore, the overhead ground wire installation structure 1A according to this embodiment can provide a technology that meets current standards and can be immediately implemented.

[0028] Furthermore, in the overhead ground wire installation structure 1A of this embodiment, as shown in Figures 1 and 2(a), the top portion 7a that constitutes the top plate 7 has a notch 8 in an area that does not overlap with the tension plate 13 when the overhead ground wire installation structure 1A is viewed in a plan view, thereby improving the air circulation and water permeability inside and outside the top of the pointed top portion P1 of the transmission tower 2. In this case, when the top plate 7 is fixed to the inside of the top of the pointed top P1 of the transmission tower 2, that is, to the main pillar material 2c that constitutes the pointed top P1, moisture can be prevented from accumulating inside the top plate. Furthermore, rainwater can penetrate into the inside of the top of the pointed top P1 of the transmission tower 2 through the notch 8 formed in the top portion 7a of the top plate 7, washing away impurities (corrosion-promoting substances) such as salt that have adhered to the inside. Therefore, according to the overhead ground wire installation structure 1A of this embodiment, it is possible to reliably slow down the rust formation on the inside of the topmost part of the pointed top portion P1 of the transmission tower 2, as well as the accompanying progression of metal corrosion and deterioration.

[0029] Therefore, when the overhead ground wire installation structure 1A of this embodiment is adopted, not only can the transmission tower 2 of this embodiment be constructed based on the transmission angle steel tower manufacturing standards, but deterioration of the top part of the pointed top portion P1 can also be effectively suppressed. In this case, the durability of the overhead ground wire installation structure 1A of this embodiment and the transmission tower 2 using the same can be improved compared to the case of adopting the overhead ground wire installation structure 20 of the conventional technology shown in Figure 5 above. As a result, the effort required for maintenance and repair of the transmission tower 2 according to this embodiment can be reduced, and further, the frequency of rebuilding the transmission tower 2 can be reduced. Therefore, according to the overhead ground wire installation structure 1A of this embodiment, the cost required for maintaining and managing the transmission tower 2 can be reduced.

[0030] [1-3: Detailed structure of the present invention] Here, the detailed structure of the overhead ground wire installation structure 1A according to this embodiment will be described with reference to Figs. In the overhead ground wire installation structure 1A of this embodiment, when the overhead ground wire installation structure 1A is viewed in a plan view, the width W1 (see Figure 2(a)) of the top portion 7a of the top plate 7 may be made to match (including the concept of approximately matching) the width W2 of the tension plate 13 (optional component). More specifically, the width W1 of the top portion 7a of the top plate 7 is the shortest distance between the notches 8, 8 in the development view of the top plate 7, as shown in FIG. 2(a). Moreover, the width W2 of the tension plate 13 is the length of the tension plate 13 in a direction perpendicular to the direction in which the overhead ground wire 14 is disposed, as shown in FIG. In the overhead ground wire installation structure 1A according to this embodiment, when the width W1 of the top portion 7a and the width W2 of the tension plate 13 are the same (including the concept of approximately the same), the area of ​​the notch 8 formed in the top portion 7a can be maximized. In this case, the effect of improving the air permeability and water permeability at the top of the pointed apex is naturally maximized. Furthermore, in the overhead ground wire installation structure 1A of this embodiment, even in this case, the top portion 7a has a width W1 that is the same as the width W2 of the tension plate 13, so that there is no problem in attaching the bolts 11 and nuts 12 when fixing the tension plate 13 to the top portion 7a. As a result, the overhead ground wire installation structure 1A of this embodiment has the effect of being able to fix the overhead ground wire 14 to the top part of the pointed top in accordance with the transmission angle steel tower manufacturing standards, while minimizing rust formation on the inside of the top part of the pointed top and the associated metal corrosion and deterioration.

[0031] Furthermore, the overhead ground wire installation structure 1A of this embodiment may have a gap D between the underside of the top portion 7a of the top plate 7 and the upper edge 9a of the side plate 9 when viewed from the side with the side plate 9 attached to the pointed top portion P1 of the transmission tower 2, as shown in Figure 2(b) (optional component). In this case, the overhead ground wire installation structure 1A of this embodiment is expected to have further improved air permeability and water permeability, in addition to the notch 8 formed in the top portion 7a of the pointed apex P1, and also has a gap D between the top plate 7 and the side plate 9 on the side surface U. In this case, the effect of suppressing rusting and the accompanying corrosion and deterioration of metal in the overhead ground wire installation structure 1A can be further improved compared to when the overhead ground wire installation structure 1A of this embodiment has only a notch 8 in the top portion 7a of the top plate 7. Therefore, as shown in Figure 2(b), according to the overhead ground wire installation structure 1A of this embodiment, which has a gap D on the side U on which the top plate 7 is not arranged at the top of the pointed apex P1, it is possible to provide an overhead ground wire installation structure and a transmission tower which are even more durable.

[0032] [2. Modifications of the present invention] Next, an overhead ground wire installation structure according to a modified example of this embodiment will be described with reference to FIG. Fig. 3(a) is a development view of the top plate and a plan view of the side plate constituting the overhead ground wire installation structure according to the modified embodiment, and (b) is a side view of the top plate and the side plate constituting the overhead ground wire installation structure according to the modified embodiment attached to the topmost part of the pointed top of the transmission tower. The same parts as those shown in Figs. 1, 2 and 4 to 6 are given the same reference numerals, and the description of the configuration is omitted. In the overhead ground wire installation structure 1A according to the above embodiment, a rectangular notch 8 is provided in the top portion 7a of the top plate 7 as an opening for improving air permeability and water permeability inside and outside the top of the pointed apex, but the shape of the opening for improving air permeability and water permeability may be other than the notch 8 shown in Figures 1 and 2(a).

[0033] More specifically, as shown in Figures 3(a) and (b), in the overhead ground wire installation structure 1B according to a modified example of this embodiment, when the overhead ground wire installation structure 1B is viewed in a plan view, a region E that does not overlap with the tension plate 13 may be provided with a plurality of holes (e.g., punched holes 19, etc.) that penetrate the thickness direction of the top portion 7a of the top plate 7' (optional components). In this case, compared to the overhead ground wire installation structure 1A of the previous embodiment, the air and water permeability inside and outside the top part of the pointed apex is slightly reduced, but the missing area in the top part 7a of the top plate 7' can be relatively reduced. In this case, the strength of the top portion 7a of the top plate 7' can be increased as compared with the previous overhead ground wire installation structure 1A. As a result, even if sufficient strength is required for the top portion 7a of the top plate 7, which is the support plate for the tension plate 13, because the construction site of the transmission tower 2 is constantly windy, the strength of the top plate 7' can be adjusted as desired by appropriately adjusting the size and total number of the punching holes 19 formed in the top portion 7a. Therefore, according to the overhead ground wire installation structure 1B relating to the modified example of this embodiment, it is possible to provide an overhead ground wire installation structure and a transmission tower having a top plate 7' with higher strength than the previous overhead ground wire installation structure 1A.

[0034] Furthermore, the overhead ground wire installation structure 1B according to the modified embodiment, like the overhead ground wire installation structure 1A described above, may have a gap D between the underside of the top portion 7a of the top plate 7' and the upper edge 9a of the side plate 9 when viewed from the side with the side plate 9 attached to the pointed top portion P1 of the transmission tower 2 (see Figure 3(b), optional component). In this case, the effect of suppressing rusting and the accompanying corrosion and deterioration of metal in the overhead ground wire installation structure 1B can be further improved compared to when the overhead ground wire installation structure 1B relating to the modified embodiment has only a plurality of through holes (e.g., punched holes 19, etc.) in region E of the top portion 7a of the top plate 7'. Therefore, as shown in Figure 3(b), according to the overhead ground wire installation structure 1B of a modified embodiment of the present embodiment, which has a gap D on the side U at the top of the pointed apex P1 on the side on which the side portion 7b of the top plate 7' is not arranged, it is possible to provide an overhead ground wire installation structure and a transmission tower having a stronger top portion 7a and even more durable. [Industrial Applicability]

[0035] INDUSTRIAL APPLICABILITY As described above, the present invention provides an overhead ground wire installation structure and a transmission tower equipped with the same that can be constructed in accordance with the production standards for power transmission angle steel towers and that can delay deterioration of the top part of the pointed top of the transmission tower, and can be used in technical fields related to power transmission facilities. [Explanation of symbols]

[0036] 1A, 1B...Overhead ground wire installation structure 2, 2'...Power transmission tower 2a...Main pole material 2b...Web material 2b1...Diagonal material 2b2...Horizontal material 2c...Main pole material 3...Power line arm 4...Power line 6...Insulator 7, 7'...Top plate 7a...Top portion 7b...Side portion 8...Notch 9...Side plate 9a...Upper edge 10...Bolt insertion hole 11...Bolt 12...Nut 13...Tension plate 13a...End portion 14...Overhead ground wire 15...Clamp 16...Jumper wire 16a...Excess length portion 17...Connecting member 18...Suspension clamp 19...Punching hole 20...Overhead ground wire installation structure (prior art) 21...Top plate 21a...Top portion 21b...Side portion 22...Side plate D...Gap S...Side edge T...End face U...Side face P1...Pointed top P2...Body P3...Leg

Claims

1. An overhead ground wire installation structure provided at the top of the pointed top of a transmission tower, A top plate is formed by bending a flat plate material into a U-shaped cross section, and has a top portion arranged on the vertically upper end surface side of the main pillar material constituting the pointed top portion, and side portions extending from each side edge of the top portion and arranged on the side surface of the transmission tower; At the pointed top portion, a side plate is provided on each of the side surfaces of the transmission tower where the side portion of the top plate is not disposed; A tension plate attached to the top portion of the top plate and to which the overhead ground wire is connected, An overhead ground wire installation structure characterized in that the top portion of the top plate has a notch for ventilation and water passage in an area that does not overlap with the tension plate when viewed in a plane.

2. When the top portion of the top plate is viewed in plan, the width W of the top portion １ and the width W of the tension plate ２ 2. The overhead ground wire attachment structure according to claim 1, wherein:

3. 2. The overhead ground wire attachment structure according to claim 1, wherein the top portion of the top plate has a plurality of holes penetrating the top portion in a thickness direction instead of the notches.

4. 4. The overhead ground wire attachment structure according to claim 1, wherein when viewed from the side with the side plate attached to the pointed apex, there is a gap between the top portion of the top plate and the upper edge of the side plate.

5. A transmission tower comprising a pointed top having the overhead ground wire attachment structure according to any one of claims 1 to 4.

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