Clamp device, protective cover, and method for laying overhead wire
The clamp device with a protective cover having a uniform cross-sectional shape and slit/split structure addresses tension fluctuations and rotational issues in trolley-passable clamps, ensuring efficient and smooth overhead line laying.
Patent Information
- Application Number
- JP2023219251
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-12-26
- Publication Date
- 2025-07-08
AI Technical Summary
Trolley-passable clamps generate vibrations due to differences in cross-sectional shapes, causing tension fluctuations and swaying in overhead lines, which can lead to loads and obstacles during laying work, and altering the clamp's compression structure is not preferable for maintaining versatility and workability.
A clamp device with a protective cover having a cylindrical body that matches the outer peripheral portion, featuring a uniform cross-sectional shape and a slit or split structure, which reduces tension fluctuations and suppresses rotational movement during overhead line laying.
The clamp device effectively minimizes tension fluctuations and rotational movement, ensuring smooth and efficient overhead line laying without compromising the clamp's versatility or workability.
Smart Images
Figure 2025102054000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a clamping device, a protective cover, and a method for laying an overhead line.
Background Art
[0002] When laying an overhead line, a clamp of the type that passes through a trolley may be attached to the terminal portion of the overhead line, and the overhead line may be extended by passing it over the trolley in that state. As a trolley-passable clamp, one configured such that a part thereof is compressed and attached to the overhead line is known (see, for example, Patent Documents 1 and 2).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] When a trolley-passable clamp passes over a trolley, vibrations are generated due to differences in the cross-sectional shapes between the compressed portion and other portions, which may cause tension fluctuations associated with the swaying of the overhead line. Such tension fluctuations can be factors such as loads on the overhead line and the clamp, and obstacles to the laying work, and therefore their occurrence should be avoided. On the other hand, changing the compression structure of the clamp itself is not preferable in terms of impairing the versatility of the clamp to be used or deteriorating the workability of the overhead line laying work.
[0005] The present disclosure provides a technique that can perform the laying work of an overhead line using a trolley-passable clamp while suppressing tension fluctuations in the overhead line and performing the laying work well.
Means for Solving the Problems
[0006] According to one aspect of the present disclosure, a clamp of the type that allows a trolley to pass through, which is attached to the terminal portion of an overhead line, and a protective cover that is a cylindrical body covering the outer peripheral portion of the clamp, are provided. The protective cover is formed in a shape in which the inner surface of the cylindrical body conforms to the outer peripheral portion, and the outer surface of the cylindrical body has the same cross-sectional shape over the entire length of the cylindrical body. A clamp device is provided.
Advantages of the Invention
[0007] According to the present disclosure, regarding the laying work of an overhead line performed using a clamp of the type that allows a trolley to pass through, the laying work can be performed well while suppressing fluctuations in the tension of the overhead line.
Brief Description of the Drawings
[0008]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6A
Figure 6B
Figure 7
Figure 8
Figure 9
Figure 10A
Figure 10B
Mode for Carrying Out the Invention
[0009] [Description of Embodiments of the Present Disclosure] [Findings Obtained by the Inventor] First, the findings obtained by the inventor of the present application will be described.
[0010] FIG. 1 is an explanatory diagram schematically showing an overview of one aspect of an overhead line laying operation. As shown in the illustration, when laying the overhead line 10, a trolley-passable clamp 20 is attached to the terminal portion of the overhead line 10, and a wire cable 30 is further connected to the clamp 20. In this state, it is passed over the trolley 40 to be used as an extension of the overhead line 10.
[0011] As the trolley-passable clamp 20, a PL (protectorless) clamp or a short clamp is used. Specifically, the following can be exemplified. FIG. 2 is an explanatory diagram showing a configuration example of a trolley-passable clamp. The illustrated clamp 20 includes a clamp body 21 and a mouth protector 22, and the clamp body 21 is configured to have a steel I-section 23, an electrical connection portion 24, and a clamp compression portion 25. Then, when a clamp compression portion 25 that constitutes a part of the clamp 20 is compressed, the clamp 20 is attached to the overhead line 10.
[0012] The clamp 20 having such a configuration is used as follows in the overhead line laying work. FIG. 3 is an explanatory diagram showing an example of the usage mode of a trolley-passing type clamp. As shown in the illustration, the clamp 20 is attached to the terminal portion of the overhead line 10, and the steel I-shaped portion 23 (i.e., the edge I-shaped portion) located at the edge on the side opposite to the overhead line 10 is connected to the wire cable 30 with connectors 33 such as the Kamalesu fitting 31 and the wire joint 32 intervening. Then, in such a connected state, it sequentially passes over the trolley 40 in the extending direction of the overhead line 10. Note that the connector 33 does not necessarily have to include both the Kamalesu fitting 31 and the wire joint 32 as shown in the illustration, and other configurations may be acceptable as long as the wire cable 30 can be connected.
[0013] At this time, in the clamp 20, there are portions with different cross-sectional shapes (particularly, portions with different sizes in the radial direction from the cross-sectional center in the longitudinal direction), such as the electrical connection portion 24 and the clamp compression portion 25 in the clamp body 21. The same applies to the clamp compression portion 25 and the mouth protector 22. Therefore, when the clamp 20 passes over the trolley 40, vibrations are generated due to the difference in cross-sectional shape, which may cause tension fluctuations accompanying the swaying of the overhead line 10. In particular, in the case of the overhead line 10, considering its length, weight, etc., the vibrations at the clamp 20 are transmitted to the overhead line 10 and become large swaying, and thus the tension fluctuations of the overhead line 10 can also become large. This can occur in exactly the same way, for example, even when a rubber tape for preventing trauma is wound around the outer peripheral portion of the clamp 20.
[0014] Such tension fluctuations can be factors such as loads on the overhead line 10 and the clamp 20 and obstacles to the laying work, so their occurrence should be avoided beforehand. On the other hand, changing the compression structure of the clamp 20 itself (i.e., the configuration having the clamp compression portion 25) is not preferable in terms of impairing the versatility of the clamp 20 to be used or deteriorating the workability of the laying work of the overhead line 10.
[0015] That is, the inventor of the present application has arrived at the finding that, regarding the laying work of the overhead line 10 performed using the trolley-passable clamp 20, it is necessary to suppress the tension fluctuation of the overhead line 10 and perform the laying work well.
[0016] In addition, when the trolley-passable clamp 20 passes over the trolley 40, there is a possibility that rotation occurs in the circumferential direction, which is the direction along the outer periphery of the clamp 20, due to the influence of vibrations of the clamp 20 or tension fluctuations of the overhead line 10. This is because the clamp 20 has a rotationally symmetric cross-sectional shape, that is, a cross-sectional shape that is likely to roll in the circumferential direction on the trolley 40, for example, the cross-section of the electrical connection part 24 is circular and the cross-section of the clamp compression part 25 is hexagonal.
[0017] FIG. 4 is an explanatory diagram showing an example of a state in which the trolley-passable clamp rotates in the circumferential direction. The illustrated example shows a state in which, due to the rotation of the clamp 20 in the circumferential direction, the movable axis direction of the connection portion between the steel I part 23 and the coupler 33 is not in the same direction as the rotation axis direction of the trolley 40 but is in a direction orthogonal to the rotation axis direction.
[0018] In such a state, when the clamp 20 passes over the trolley 40, depending on conditions such as the contact angle between the clamp 20 and the coupler 33 and the trolley 40 and the tension of the overhead line 10, the load on the base of the steel I part 23 may become excessive, and as a result, damage such as bending of the steel I part 23 may occur. Such damage that can occur in the clamp can be a factor such as a load on the overhead line 10 or an obstacle to the laying work, and therefore, its occurrence should be avoided beforehand.
[0019] That is, regarding the trolley-passable clamp 20, the inventor of the present application has arrived at the finding that it is necessary to suppress the occurrence of rolling in the circumferential direction when passing over the trolley 40, thereby enabling the laying work of the overhead line 10 using the clamp 20 to be performed well.
[0020] The findings described above are novel and can only be known by those on-site who actually conduct the overhead line laying work. To solve various problems based on such findings, the inventor of the present application has come up with the clamp device, protective cover, and overhead line laying method described in the following embodiments.
[0021] <Embodiments of the present disclosure> Next, embodiments of the present disclosure will be listed and described.
[0022] [1] The clamp device according to one aspect of the present disclosure is a pulley-passable clamp attached to the terminal part of the overhead line, and a protective cover which is a cylindrical body covering the outer peripheral part of the clamp, and the protective cover is formed in a shape where the inner cylindrical surface of the cylindrical body matches the outer peripheral part, and the outer cylindrical surface of the cylindrical body has the same cross-sectional shape over the entire length of the cylindrical body. According to this configuration, by covering the outer peripheral part of the clamp with a protective cover having the same cross-sectional shape over the entire length, it is possible to suppress the tension fluctuation of the overhead line caused by vibration when passing over the pulley.
[0023] [2] In the clamp device according to [1] above, the cross-sectional shape is an oval shape having a major axis part and a minor axis part. According to this configuration, it is possible to suppress the rotation of the clamp in the circumferential direction when passing over the pulley.
[0024] [3] In the clamp device according to [2] above, the oval shape is an elliptical shape. According to this configuration, while suppressing the rotation of the clamp in the circumferential direction, it is possible to smoothly pass over the pulley.
[0025] [4] In the clamp device according to [2] or [3] above, The protective cover is configured such that, in a state of being attached to the outer peripheral portion, the radial direction of the major axis portion in the cross-sectional shape is the same as the axial direction of the through-hole provided in the edge I-shaped portion of the clamp. According to this configuration, it is possible to suppress the occurrence of damage to the edge I-shaped portion when passing over the bobbin.
[0026] [5] In the clamp device according to any one of [1] to [4] above, The protective cover has a slit extending along the axial direction of the cylindrical body and a cylindrical opening / closing structure utilizing the elasticity of the cylindrical body. According to this configuration, it is possible to improve the work efficiency when attaching the protective cover.
[0027] [6] In the clamp device according to any one of [1] to [4] above, The protective cover has a split structure that can be divided along the axial direction of the cylindrical body. According to this configuration, it is possible to sufficiently ensure the ease of forming the protective cover.
[0028] [7] In the clamp device according to any one of [1] to [6] above, The protective cover has a receiving groove for a binding band wound around the cylindrical body on the outer cylindrical surface of the cylindrical body. According to this configuration, while enabling the fixing of the protective cover by the binding band, it is possible to avoid the binding band from becoming an obstacle when passing over the bobbin even in that case.
[0029] [8] The protective cover according to another aspect of the present disclosure is configured as a cylindrical body that covers the outer peripheral portion of a bobbin-passing type clamp attached to the terminal portion of an overhead line, the inner cylindrical surface of the cylindrical body is formed in a shape that conforms to the outer peripheral portion, the outer cylindrical surface of the cylindrical body has the same cross-sectional shape over the entire length of the cylindrical body. According to this configuration, by covering the outer peripheral portion of the clamp with a protective cover having the same cross-sectional shape over the entire length, it is possible to suppress the tension fluctuation of the overhead line caused by the vibration when passing over the trolley.
[0030] [9] The method for laying an overhead line according to still another aspect of the present disclosure is a procedure for attaching a trolley-passable clamp to the terminal portion of the overhead line, and a procedure for covering the outer peripheral portion of the clamp with a protective cover configured as a cylindrical body, and includes as the protective cover, a cylindrical body is used in which the inner surface of the cylindrical body is formed in a shape that matches the outer peripheral portion, and the outer surface of the cylindrical body has the same cross-sectional shape over the entire length of the cylindrical body. According to this configuration, by covering the outer peripheral portion of the clamp with a protective cover having the same cross-sectional shape over the entire length, it is possible to suppress the tension fluctuation of the overhead line caused by the vibration when passing over the trolley.
[0031] [Details of Embodiments of the Present Disclosure] Next, embodiments of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, and is intended to be represented by the claims and to include all modifications within the meaning and scope equivalent to the claims.
[0032] [First Embodiment of the Present Disclosure] Here, a clamp device, a protective cover, and a method for laying an overhead line according to the first embodiment of the present disclosure will be described with specific examples.
[0033] (1) Configuration of Clamp Device First, the configuration of the clamp device according to the first embodiment will be described. When laying the overhead line 10, the clamp device is attached to the terminal portion of the overhead line 10, and the edge side opposite to the overhead line 10 is connected to the coupler 33 and the wire cable 30. That is, the clamp device is used at the location where the clamp 20 shown in FIG. 1 is arranged.
[0034] FIG. 5 is an explanatory diagram showing a configuration example of the clamp device according to the first embodiment. The illustrated clamp device 1 is generally configured to include a clamp 20 and a protective cover 50 that covers the outer peripheral portion thereof.
[0035] The clamp 20 can be a reused existing one (for example, those shown in FIGS. 1 and 2). Thereby, the versatility of the clamp 20 can be sufficiently ensured, which also contributes to suppressing the deterioration of the workability of laying the overhead line 10.
[0036] Specifically, as described above, as the clamp 20, a clamp body 21 and a mouth protector 22 are provided, and it is possible to use a clamp body 21 having a steel I portion 23, an electrical connection portion 24, and a clamp compression portion 25. A connector 33 interposed between the wire cable 30 is movably connected to the steel I portion 23 by using a through hole 26 provided in the steel I portion 23. Further, the clamp compression portion 25 is configured to be attached to the overhead line 10 by compressing its outer shape in the diameter-reducing direction.
[0037] Note that when the clamp compression portion 25 of the clamp 20 is compressed, there are portions where the cross-sectional shapes are different (particularly, portions with different diameters in the radial direction) at least between the electrical connection portion 24 and the clamp compression portion 25. For example, the cross-sectional shape of the electrical connection portion 24 is circular, while the cross-sectional shape of the clamp compression portion 25 is hexagonal, and the circumscribed circle of the hexagon is smaller in diameter than the electrical connection portion 24.
[0038] The outer peripheral portion of such a clamp 20 is covered by the protective cover 50. Hereinafter, a configuration example of the protective cover 50 that covers the clamp 20 will be described.
[0039] (2) Configuration of the protective cover FIG. 6A is a side cross-sectional view showing a configuration example of the protective cover according to the first embodiment, and FIG. 6B is a cross-sectional view taken along line A-A in FIG. 6A. The protective cover 50 of the legend is configured as a cylindrical body having an inner cylindrical surface 51 and an outer cylindrical surface 52, and by enclosing the clamp 20 inside the cylinder of the cylindrical body, it covers the outer peripheral portion of the clamp 20.
[0040] In the present embodiment, the outer peripheral portion of the clamp 20 covered by the protective cover 50 is the portion of the electrical connection portion 24 and the clamp compression portion 25 of the clamp body 21, excluding the mouth protection tool 22 and the steel I portion 23 of the clamp body 21. The mouth protection tool 22 can be bent according to the overhead line 10, and since the connecting tool 33 for connecting the steel I portion 23 can move, this is to prevent these movements from being hindered. Therefore, the total length (length in the cylinder axis direction) of the cylindrical body is set so that the protective cover 50 covers the outer peripheral portions of the electrical connection portion 24 and the clamp compression portion 25.
[0041] The inner cylindrical surface 51 of the protective cover 50 is formed in a shape that matches the outer peripheral portion of the clamp 20. In the present embodiment, the inner cylindrical surface 51 is formed in a shape that matches the outer peripheral portions of the electrical connection portion 24 and the clamp compression portion 25. Specifically, as the inner cylindrical surface 51, there are a circular portion 51a that matches the electrical connection portion 24 and a hexagonal (for example, refer to FIG. 6B) portion 51b that matches the clamp compression portion 25. That is, since the cross-sectional shapes of the electrical connection portion 24 and the clamp compression portion 25 are different, in the inner cylindrical surface 51 as well, portions 51a and 51b with different cross-sectional shapes are mixed in the total length of the cylindrical body so as to match the respective cross-sectional shapes.
[0042] Thus, since the inner cylindrical surface 51 is in a shape that matches the outer peripheral portion of the clamp 20, when the outer peripheral portion of the clamp 20 is covered with the protective cover 50, there is no useless gap between the outer peripheral portion of the clamp 20 and the inner cylindrical surface of the protective cover 50. Moreover, if it includes a portion 51b having a cross-sectional shape such as the hexagonal portion of the clamp compression portion 25 as the matching cross-sectional shape, there will be no circumferential mounting deviation of the protective cover 50 with respect to the clamp 20 in the state where the outer peripheral portion of the clamp 20 is covered with the protective cover 50.
[0043] Regarding the hexagonal portion 51b of the inner cylindrical surface 51 of the protective cover 50 that corresponds to the clamp compression portion 25, it is preferable that escape grooves 54 are formed at each of the corners of the hexagon (see, for example, FIG. 6B).
[0044] The outer cylindrical surface 52 of the protective cover 50 has the same cross-sectional shape over the entire length of the cylindrical body. That is, unlike the inner cylindrical surface 51, the outer cylindrical surface 52 does not change in cross-sectional shape over the entire length of the cylindrical body. Here, the "cross-sectional shape of the outer cylindrical surface 52" refers to the two-dimensional shape defined by the outer cylindrical surface 52 of the protective cover 50 in the cross-section of the protective cover 50. That is, the "cross-sectional shape of the outer cylindrical surface 52" referred to here is the contour shape corresponding to the outer edge of the cross-section of the protective cover 50.
[0045] The cross-sectional shape of the outer cylindrical surface 52 is an oval shape having a major axis portion (see D1 in FIG. 6B) and a minor axis portion (see D2 in FIG. 6B). Here, the "oval shape" refers to a shape surrounded by a closed curve in which the distance (diameter) from the center is not uniform and has a major axis portion and a minor axis portion. Specifically, an oval shape, an oblong shape, an elliptical shape, etc. are applicable. In the present embodiment, in particular, the oval shape is an elliptical shape. Here, the "elliptical shape" refers to a shape represented by the locus of points where the sum of the distances from two different fixed points (foci) is constant.
[0046] The protective cover 50 having the outer cylindrical surface 52 with such a cross-sectional shape is configured such that the cross-sectional shape of the outer cylindrical surface 52 has the following relationship with respect to the clamp 20 whose outer peripheral portion is covered by the protective cover 50. That is, when the protective cover 50 is attached to the outer peripheral portion of the clamp 20, the radial direction of the major axis portion (see D1 in FIG. 6B) in the cross-sectional shape of the outer cylindrical surface 52 of the protective cover 50 is the same as the axial direction of the through-hole 26 provided in the steel I portion 23 which is the edge I-type portion of the clamp 20. The positions of the major axis portion and the minor axis portion of the outer cylindrical surface 52 with respect to the hexagonal portion 51b of the inner cylindrical surface 51 that matches the clamp compression portion 25 are set.
[0047] The protective cover 50 is provided with a slit 53 extending along the axial direction of the cylindrical body. The slit 53 is formed so as to connect the outer cylindrical surface 52 and the inner cylindrical surface 51. At a location facing the formation position of the slit 53, a larger escape groove 54 is formed than other locations. And the protective cover 50 is formed of an elastic material. With such a configuration, the protective cover 50 has a structure that can open the formation location of the slit 53 and expose the inside of the cylindrical body while utilizing the elasticity of the formation material, that is, a cylinder opening / closing structure.
[0048] The protective cover 50 does not necessarily have to have a cylinder opening / closing structure, and may have, for example, a split structure that can be divided along the axial direction of the cylindrical body as long as it is possible to expose the inside of the cylindrical body. In the case of a split structure, the formation material of the protective cover 50 does not necessarily need to have elasticity. Here, the "split structure" refers to a structure in which the protective cover 50 is divided into two parts. Therefore, the "split structure" includes, in addition to a structure in which the two parts are equal (that is, each part constitutes half of the protective cover 50), a structure in which the two parts are divided unevenly (for example, when the circumferential direction is divided into six equal parts, the ratio of each part is 4:2).
[0049] As the formation material of the protective cover 50, those having excellent weather resistance and moderate elasticity can be used. For example, in the case of having a cylinder opening / closing structure, hard urethane rubber, silicone rubber, etc. can be mentioned as the formation material. Also, in the case of having a split structure, in addition to the above-mentioned formation materials, aluminum, iron, steel materials, monomer cast nylon, etc. of the same material as the clamp can be mentioned as the formation material.
[0050] In any case of the structure, it is preferable that a receiving groove 55 for a binding band wound around the cylindrical body is formed on the outer cylindrical surface 52 of the protective cover 50 so as to surround the cylindrical body in the circumferential direction. In the example shown in Fig. 6A, the case where a plurality (for example, two) of receiving grooves 55 are formed is shown.
[0051] (3) Procedure of the overhead line laying method Next, the procedure of the overhead line 10 laying work performed using the clamp device 1 having the above-described configuration, that is, the procedure of the overhead line laying method according to the first embodiment of the present disclosure, will be described.
[0052] When laying the overhead line 10, first, the clamp 20 is attached to the terminal portion of the overhead line 10. The attachment of the clamp 20 is performed by compressing the clamp compression portion 25. And after the attachment of the clamp 20, the mouth protection tool 22 is attached to the overhead line side of the clamp 20. Thereafter, the camless fitting 31 and the wire joint 32 are connected through the steel I portion through hole 26, and the wire cable 30 is attached. When a slight tension is applied (in a state of floating in the air), the protective cover 50 is attached so as to cover the outer peripheral portion of the clamp 20. Finally, a rubber tape is wound from above the protective cover 50 to about 1 meter beyond the overhead line (the length of winding the rubber tape varies depending on the wire type, size, and stringing conditions of the overhead line). Winding the rubber tape also serves to prevent the protective cover 50 from coming off and to prevent deformation when the trolley 40 of the overhead line 10 passes through.
[0053] At this time, if the protective cover 50 has a cylindrical opening / closing structure, the protective cover 50 which is a single part (integral part) is attached, so that the complication of the work due to an increase in the number of parts can be suppressed, and the work efficiency can be improved. Also, if the protective cover 50 has a split structure, the degree of freedom in selecting the forming material of the protective cover 50 is improved, and the facilitation of the forming process (for example, simplification of the mold) can also be achieved. That is, the ease of forming the protective cover 50 can be sufficiently ensured.
[0054] When the protective cover 50 is attached, the outer peripheral portion of the clamp 20 excluding the mouth protection tool 22 and the steel I portion 23 is covered by the protective cover 50 having a cylindrical outer surface 52 with the same cross-sectional shape over the entire length of the cylindrical body. Since the protective cover 50 covering the outer peripheral portion of the clamp 20 has a cylindrical inner surface 51 having a shape that matches the outer peripheral portion, no mounting deviation in the circumferential direction occurs after attachment.
[0055] Regarding the protective cover 50 that covers the outer peripheral portion of the clamp 20, the protective cover 50 can be fixed so as not to fall off from the clamp 20 by winding a binding band such as a zip tie or a wire around the entire circumference thereof. At this time, if the binding band is positioned in the groove of the accommodation groove 55 formed on the cylindrical outer surface 52 of the protective cover 50, it is possible to fix the protective cover 50 with the binding band, and even in that case, it is possible to avoid any hindrance when the binding band passes over the pulley 40. Alternatively, it may be wound and fixed using vinyl tape or the like.
[0056] In this way, a clamp device 1 including a clamp 20 and a protective cover 50 is mounted on the terminal portion of the overhead line 10.
[0057] After the clamp device 1 is mounted, the steel I portion 23 located at the edge on the side opposite to the overhead line 10 in the clamp device 1 is connected to the wire cable 30 with the coupler 33 interposed therebetween. And in that state, it is provided along the extension line of the overhead line 10. As a result, these will pass over the pulley 40 in the order of the wire cable 30, the coupler 33, the clamp device 1, and the overhead line 10. At the end of the overhead line 10 on the opposite side, they will pass over the pulley 40 in the order of the overhead line 10, the clamp device 1, the coupler 33, and the wire cable 30.
[0058] FIG. 7 is an explanatory diagram showing an example of the state when the clamp device passes over the pulley in the laying method of the overhead line according to the first embodiment. As shown in the legend, while the clamp device 1 is attached to the terminal part of the overhead line 10, it passes over the pulley 40 with the coupler 33 and the wire cable 30 connected. At this time, the clamp 20 in the clamp device 1 has its outer peripheral portion covered by a protective cover 50 having a cylindrical outer surface 52 with the same cross-sectional shape over the entire length of the cylindrical body. Therefore, when the clamp device 1 passes over the pulley 40, the cylindrical outer surface 52 of the protective cover 50 comes into contact with the pulley 40, so that vibrations caused by differences in the cross-sectional shape of the cylindrical outer surface 52 can be reduced. If the vibration of the clamp device 1 can be reduced, the swaying and tension fluctuations of the overhead line 10 caused by the vibration can be reduced until they do not damage the overhead line or the clamp.
[0059] Therefore, if the laying work of the overhead line 10 is carried out using the clamp device 1, it becomes possible to prevent the occurrence of vibrations when the clamp device 1 passes over the pulley 40 and tension fluctuations of the overhead line 10 accompanying swaying of the overhead line 10 and the like. Moreover, in order to avoid tension fluctuations of the overhead line 10, it is not necessary to change the compression structure of the clamp 20 itself (that is, the configuration provided with the clamp compression part 25).
[0060] If it is possible to avoid tension fluctuations of the overhead line 10, the tension fluctuations will not become factors such as a load on the overhead line 10 or an obstacle to the laying work. That is, by suppressing the tension fluctuations of the overhead line 10, the laying work of the overhead line 10 can be carried out well.
[0061] When the clamp device 1 passes over the pulley 40, the cylindrical outer surface 52 of the protective cover 50 comes into contact with the pulley 40. FIG. 8 is an explanatory diagram showing an example of the cross-sectional shape of a clamp device passing over a pulley in a method for laying an overhead line according to the first embodiment. As shown in the legend, the cylindrical outer surface 52 of the protective cover 50 covering the outer peripheral portion of the clamp 20 has an elliptical cross-sectional shape and has a major axis portion and a minor axis portion. Therefore, the clamping device 1 passes over the worm wheel 40 while being guided by the guide groove in the worm wheel 40 in a state where the radial direction of the minor axis portion of the protective cover 50 is in the same direction as the radial direction of the worm wheel 40, and the radial direction of the major axis portion is in a direction (for example, a perpendicular direction) intersecting the radial direction of the worm wheel 40. That is, among the cylindrical outer surface 52 of the protective cover 50, the outer surface that constitutes the minor axis portion comes into contact with the groove bottom of the guide groove in the worm wheel 40 and passes over the worm wheel 40. This is because the moment from the rotation center of the worm wheel 40 acting on the clamping device 1 is smaller when the constituent surface of the minor axis portion is in contact than when the constituent surface of the major axis portion is in contact. Therefore, an action to maintain the state where the constituent surface of the minor axis portion is in contact acts on the clamping device 1, making it difficult for rotation (rolling) in the circumferential direction to occur.
[0062] In this way, if the cylindrical outer surface 52 of the protective cover 50 has a cross-sectional shape having a major axis portion and a minor axis portion, by utilizing the difference in the diameter dimensions between the major axis portion and the minor axis portion, it can be passed over the worm wheel 40 with the constituent surface of the minor axis portion in contact. Moreover, by the action of trying to maintain that state, the generation of rotation in the circumferential direction of the clamping device 1 when the clamping device 1 passes over the worm wheel 40 can be suppressed.
[0063] In particular, if the cross-sectional shape having a major axis portion and a minor axis portion is an elliptical shape, the constituent surface of the minor axis portion in contact with the guide groove of the worm wheel 40 becomes a curved surface, so it follows the groove shape of the guide groove. Therefore, for the protective cover 50 having the cylindrical outer surface 52 with such a cross-sectional shape, it can pass smoothly over the worm wheel 40 while suppressing rotation in the circumferential direction when passing over the worm wheel 40. As a result, the laying work of the overhead line 10 can be performed well. Note that when the cross-sectional shape is an elliptical shape, the elliptical shape is such that the diameter dimension D1 of the major axis portion is smaller than the maximum groove width L of the guide groove of the worm wheel 40, and the diameter dimension of the minor axis portion is set to be even smaller than the diameter dimension D1 (see FIG. 8).
[0064] When the outer surface 52 of the cylinder has a cross-sectional shape having a major axis portion and a minor axis portion, in the state of being attached to the outer peripheral portion of the clamp 20, the radial direction of the major axis portion is the same as the axial direction of the through hole 26 in the steel I portion 23 of the clamp 20. Therefore, if the protective cover 50 passes over the bobbin 40 while the constituent surface of the minor axis portion is in contact, and the rotation of the protective cover 50 in the circumferential direction is suppressed by maintaining this state, the clamp device 1 will pass over the bobbin 40 while maintaining the state where the axial direction of the through hole 26 in the steel I portion 23 is the same as the rotation axis of the bobbin 40.
[0065] If it passes over the bobbin 40 in such a state, the clamp device 1 will not have its movable state between the clamp 20 and the coupler 33 hindered regardless of conditions such as the holding angle with the bobbin 40 and the tension of the overhead line 10. Therefore, regardless of the conditions when passing over the bobbin 40, by ensuring the movable state between the clamp 20 and the coupler 33, it is possible to suppress the load on the base of the steel I portion 23 from becoming excessive. As a result, it is possible to eliminate the risk of damage such as bending occurring in the steel I portion 23, and it is possible to avoid in advance the occurrence of a load on the overhead line 10 and an obstacle to the laying work.
[0066] Through the above-described respective procedures, by extending the overhead line 10, the overhead line 10 will be laid.
[0067] (4) Effects according to this embodiment According to this embodiment, one or more of the following effects are achieved.
[0068] (a) According to this embodiment, since the outer cylindrical surface 52 of the protective cover 50 covering the outer peripheral portion of the clamp 20 has the same cross-sectional shape over the entire length, when the clamping device 1 passes over the trolley 40, vibrations caused by differences in the cross-sectional shape of the outer cylindrical surface 52 can be reduced. If the vibration of the clamping device 1 is small, the sway of the overhead line 10 caused by the vibration can also be reduced. Therefore, by performing the laying work of the overhead line 10 using the clamping device 1, the occurrence of tension fluctuations in the overhead line 10 can be minimized. If the tension fluctuations in the overhead line 10 can be minimized, the tension fluctuations will not cause factors such as load on the overhead line 10 and obstacles to the laying work. That is, by suppressing the tension fluctuations in the overhead line 10, the laying work of the overhead line 10 can be performed well.
[0069] (b) According to this embodiment, since the cross-sectional shape of the outer cylindrical surface 52 of the protective cover 50 is an oval shape having a major axis portion and a minor axis portion, by utilizing the difference in the diameter dimensions between the major axis portion and the minor axis portion, when the clamping device 1 passes over the trolley 40, the generation of rotation in the circumferential direction of the clamping device 1 (particularly, the clamp 20 constituting the clamping device 1) can be suppressed.
[0070] (c) According to this embodiment, since the cross-sectional shape of the outer cylindrical surface 52 of the protective cover 50 is an elliptical shape, while suppressing the rotation in the circumferential direction when passing over the trolley 40, the contact surface of the protective cover 50 with the trolley 40 conforms to the groove shape of the guide groove of the trolley 40. Therefore, it can pass smoothly over the trolley 40, and as a result, the laying work of the overhead line 10 can be performed well.
[0071] (d) According to this embodiment, the outer cylindrical surface 52 of the protective cover 50 has a cross-sectional shape having a major diameter portion and a minor diameter portion. In the state of being attached to the outer peripheral portion of the clamp 20, the radial direction of the major diameter portion of the outer cylindrical surface 52 is the same as the axial direction of the through hole 26 in the steel I portion 23 of the clamp 20. Therefore, the clamp device 1 will pass over the bobbin 40 while maintaining the state where the axial direction of the through hole 26 in the steel I portion 23 is the same as the rotation axis of the bobbin 40. Passing over the bobbin 40 in such a state will ensure the movable state of the clamp 20 and the connecting tool 33, and suppress the excessive load on the base of the steel I portion 23. As a result, it is possible to eliminate the possibility of damage such as bending occurring in the steel I portion 23, and it is possible to avoid the load on the overhead line 10 and the hindrance to the laying work.
[0072] (e) As described in this embodiment, if the protective cover 50 has a cylindrical opening / closing structure, the protective cover 50, which is a single part (integrated part), will be attached. Therefore, it is possible to suppress the complication of the work due to the increase in the number of parts and improve the work efficiency.
[0073] (f) As described in this embodiment, if the protective cover 50 has a split structure, the degree of freedom in selecting the forming material of the protective cover 50 is improved, and the ease of forming processing (for example, simplification of the mold) can also be achieved. That is, the ease of forming the protective cover 50 can be sufficiently ensured.
[0074] (g) According to this embodiment, for the protective cover 50 that covers the outer peripheral portion of the clamp 20, it can be fixed so as not to fall off from the clamp 20 by winding a binding band. Moreover, by positioning the binding band in the groove of the accommodation groove 55 formed on the outer cylindrical surface 52 of the protective cover 50, it is possible to fix the protective cover 50 with the binding band, and even in that case, it is possible to avoid the binding band from becoming an obstacle when passing over the bobbin 40.
[0075] <The second embodiment of the present disclosure> Next, a second embodiment of the present disclosure will be described. Here, mainly, differences from the case of the first embodiment described above will be explained. For points not described here, they may be the same as in the case of the first embodiment.
[0076] FIG. 9 is an explanatory diagram showing a configuration example of a clamp device according to the second embodiment. The illustrated clamp device 2 is configured to include a clamp 20 and a protective cover 60 that covers the outer peripheral portion thereof, similar to the case of the first embodiment described above. However, the protective cover 60 is different from the case of the first embodiment.
[0077] In the present embodiment, the outer peripheral portion of the clamp 20 covered by the protective cover 60 is the portion of the clamp compression part 25. That is, unlike the case of the first embodiment, the electrical connection part 24 in the clamp 20 remains exposed without being covered by the protective cover 60. Therefore, the total length (length in the cylinder axis direction) of the cylindrical body is set so that the protective cover 60 covers the outer peripheral portion of the clamp compression part 25.
[0078] FIG. 10A is a side sectional view showing a configuration example of the protective cover according to the second embodiment, and FIG. 10B is a view taken along arrow B in FIG. 10A. The illustrated protective cover 60 is configured as a cylindrical body having an inner cylinder surface 61 and an outer cylinder surface 62, and by enclosing the clamp 20 inside the cylindrical body, it covers the outer peripheral portion of the clamp compression part 25 of the clamp 20.
[0079] The inner cylinder surface 61 of the protective cover 60 is formed in a shape that matches the outer peripheral portion of the clamp compression part 25 of the clamp 20. This point is the same as in the case of the first embodiment except that the electrical connection part 24 of the clamp 20 is not covered.
[0080] The outer cylinder surface 62 of the protective cover 60 has the same cross-sectional shape over the entire length of the cylindrical body. That is, the cross-sectional shape of the outer cylinder surface 62 does not change over the entire length of the cylindrical body.
[0081] The cross-sectional shape of the outer surface 62 of the cylinder is the same as the cross-sectional shape of the outer peripheral portion of the electrical connection portion 24 of the clamp 20. Here, the same shape means shapes that are identical to each other or have a small difference such that they can be regarded as the same.
[0082] When the outer peripheral portion of the clamp compression part 25 is covered with the protective cover 60 having the outer surface 62 of such a cross-sectional shape, the clamp device 2 will have the same cross-sectional shape for the entire length of the range from the electrical connection part 24 to the protective cover 60 for the outer peripheral portion.
[0083] Therefore, also in this embodiment, if the laying work of the overhead line 10 is performed using the clamp device 2, the generation of tension fluctuations in the overhead line 10 associated with vibrations when the clamp device 2 passes over the carriage 40 or swaying of the overhead line 10 can be minimized. If the tension fluctuations in the overhead line 10 can be minimized, such tension fluctuations will not be factors such as a load on the overhead line 10 or an obstacle to the laying work. That is, by suppressing the tension fluctuations in the overhead line 10, the laying work of the overhead line 10 can be performed well.
[0084] <Modifications, etc.> As described above, the first and second embodiments of the present disclosure have been specifically described, but the present disclosure is not limited to the above-described embodiments, and various changes can be made without departing from the gist thereof.
[0085] In each of the above-described embodiments, the clamp 20 attached to the terminal portion of the overhead line 10 has been described with specific examples, but it is not necessarily limited to the configurations exemplified in each embodiment. That is, as long as it is a carriage-passing type clamp that can be used for the laying work of the overhead line 10, even if it is different from the configurations exemplified in each embodiment, the content of the present disclosure can be applied in exactly the same manner.
[0086] For example, regarding the clamp compression part 25 in the clamp 20, in each of the above-described embodiments, the case where the cross-sectional shape is hexagonal was exemplified, but other cross-sectional shapes may be used. In that case, it suffices that the inner surface of the cylinder of the protective cover is formed to match the other cross-sectional shape.
[0087] Also, regarding the configurations other than the protective cover, substitutions or changes may be made to the configurations exemplified in each of the above-described embodiments.
Explanation of Reference Numerals
[0088] 1 Clamp device 2 Clamp device 10 Overhead line 20 Clamp 21 Clamp body 22 Mouth protector 23 Steel I part 24 Electrical connection part 25 Clamp compression part 26 Through hole 30 Wire cable 31 Camless fitting 32 Wire joint 33 Connector 40 Pulley 50 Protective cover 51 Inner surface of cylinder 52 Outer surface of cylinder 53 Slit 54 Escape groove 55 Accommodation groove 60 Protective cover 61 Inner surface of cylinder 62 Outer surface of cylinder
Claims
1. A clamp of the type that allows a trolley to pass through, which is attached to the terminal part of an overhead line, and a protective cover, which is a cylindrical body that covers the outer peripheral part of the clamp, and the protective cover is provided with: the inner cylindrical surface of the cylindrical body is formed in a shape that matches the outer peripheral part, and the outer cylindrical surface of the cylindrical body has the same cross-sectional shape over the entire length of the cylindrical body A clamp device.
2. The cross-sectional shape is an oval shape having a major axis part and a minor axis part The clamp device according to claim 1.
3. The oval shape is an elliptical shape The clamp device according to claim 2.
4. The protective cover is configured such that, in the state of being attached to the outer peripheral part, the radial direction of the major axis part in the cross-sectional shape is the same as the axial direction of the through-hole provided in the edge I-shaped part of the clamp. The clamp device according to claim 2 or 3.
5. The protective cover has a slit extending along the axial direction of the cylindrical body and a cylindrical opening / closing structure using the elasticity of the cylindrical body. The clamp protective cover according to claim 1.
6. The protective cover has a split structure that can be divided along the axial direction of the cylindrical body. The clamp device according to claim 1.
7. The protective cover has a receiving groove for a binding band wound around the cylindrical body on the outer cylindrical surface of the cylindrical body. The clamp device according to claim 1.
8. It is configured as a cylindrical body that covers the outer peripheral part of a trolley-passing type clamp attached to the terminal part of an overhead line, the inner cylindrical surface of the cylindrical body is formed in a shape that matches the outer peripheral part, and the outer cylindrical surface of the cylindrical body has the same cross-sectional shape over the entire length of the cylindrical body A protective cover.
9. A procedure for attaching a trolley-passing type clamp to the terminal part of an overhead line, and a procedure for covering the outer peripheral part of the clamp with a protective cover configured as a cylindrical body, and as the protective cover, one in which the inner cylindrical surface of the cylindrical body is formed in a shape that matches the outer peripheral part and the outer cylindrical surface of the cylindrical body has the same cross-sectional shape over the entire length of the cylindrical body is used. A method for laying an overhead line.
Citation Information
Patent Citations
Sheave-passed type short anchor clamp
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