V-shaped suspension system, and V-shaped suspension system with impulse horn

Abstract

To suppress buckling of insulators in V-suspension devices. [Solution] The V-shaped suspension device 10 is a device for supporting the main line of an overhead power transmission line, and comprises a first insulator 21 and a second insulator 22 arranged so that their axial lower ends are close together to form a V shape, and a yoke 40 connected to the lower ends of the first insulator 21 and the second insulator 22. The first insulator 21 and the second insulator 22 each comprise a core member 25 and an outer sheath 26 having a body portion 27 and a plurality of cap portions 28, and are integral polymer insulators that do not have a structure in which a plurality of insulators are connected in the axial direction. The core diameter D [mm] of the core member 25 and the insulator length L [mm] of the first insulator 21 and the second insulator 22 each satisfy formula (1). 4 / L 2 >0.5883 (1)

Description

[Technical Field]

[0001] The present invention relates to a V-suspension device and a V-suspension device with an impulse horn. [Background technology]

[0002] Conventionally, V-shaped suspension devices are known for insulating a conductor from a supporting tower (for example, Patent Documents 1 and 2). A V-shaped suspension device comprises two insulator devices whose lower ends are arranged to form a V shape with each other, and a plate-shaped yoke connected to the lower ends of the two insulator devices. In Patent Document 1, the two insulator devices are constructed as polymer insulators, with a core member made of FRP mainly composed of epoxy resin covered with an outer covering such as silicone rubber. The V-shaped suspension device in Patent Document 1 supports jumper wires on a tower and prevents the jumper wires from swaying due to strong winds, etc. In Patent Document 2, the two insulator devices each have a structure in which long trunk insulators are connected axially by metal fittings to the required length. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2017-46554 [Patent Document 2] Japanese Patent Application Publication No. 35-3727 [Overview of the project] [Problems that the invention aims to solve]

[0004] The inventors considered using a V-shaped suspension device equipped with polymer insulators, as described in Patent Document 1, to support the main line of an overhead power transmission line stretched between towers, rather than to support jumper wires. However, since the main line is longer and heavier than jumper wires, the load on the V-shaped suspension device for the main line, including the weight of the wires and wind pressure, is significantly larger than that on the V-shaped suspension device for jumper wires. As a result, there was a problem in that the insulators (especially the core members) of the V-shaped suspension device would buckle due to the load.

[0005] This invention was made to solve these problems, and its main objective is to suppress buckling of insulators in V-suspension devices. [Means for solving the problem]

[0006] To achieve the main objectives described above, the present invention employs the following means.

[0007] [1] The V-suspension device of the present invention is A V-shaped suspension device for supporting the main line of an overhead power transmission line, A first insulator and a second insulator are arranged such that their lower ends in the axial direction are close together to form a V shape, A yoke connected to the lower end of the first insulator and the lower end of the second insulator, Equipped with, The first and second insulators are each integral polymer insulators comprising a core member and an outer covering mainly composed of an insulating polymer material having a body portion and a plurality of cap portions, and do not have a structure in which a plurality of insulators are connected in the axial direction. The first insulator and the second insulator each satisfy the following formula (1): the core diameter D [mm] of the core member and the insulator length L [mm]. D 4 / L 2 >0.5883 (1) It is.

[0008] In this V-suspension device, the first and second insulators satisfy equation (1) with respect to the core diameter D and insulator length L, respectively. This suppresses buckling of the first and second insulators in the V-suspension device.

[0009] [2] In the V-suspension device described above (the V-suspension device described in [1] above), the first insulator and the second insulator may each have a core diameter D of 29 mm or more.

[0010] [3] In the above-described V suspension device (the V suspension device described in [1] or [2] above), the core diameters D of the first insulator and the second insulator may each be 65 mm or less.

[0011] [4] In the above-described V suspension device (the V suspension device described in any one of [1] to [3] above), the angle θ, which is the angle formed between the axial direction of the first insulator and the axial direction of the second insulator, may be 60° or more.

[0012] [5] In the above-described V suspension device (the V suspension device described in any one of [1] to [4] above), at least one of the first insulator and the second insulator may be provided with a connecting portion that forms the lower end portion and is connected to the yoke at at least two locations. In this way, when a horizontal load is applied to the yoke via the overhead transmission line due to wind pressure, rotation of the yoke relative to the first insulator and the second insulator can be suppressed. Thereby, it is possible to suppress the application of forces other than the axial direction to the first insulator and the second insulator, and the load-bearing performance of the V suspension device is improved.

[0013] [6] The V suspension device with an impulse horn according to the present invention is the above-described V suspension device (the V suspension device described in any one of [1] to [5] above) and an impulse horn that can be attached to a tower that supports the overhead transmission line via the V suspension device, and the V suspension device has one or more shielding rings disposed around the lower end portions of the first insulator and the second insulator. It is such a device.

[0014] This V suspension device with an impulse horn can protect the first insulator and the second insulator from lightning strikes by including the impulse horn and the shielding ring. In this case, the impulse horn may be in a state of being attached to the tower, or may be in a state before attachment.

Brief Description of the Drawings

[0015] [Figure 1] Explanatory drawing of the V suspension device 1 with an impulse horn. [Figure 2] Explanatory drawing of the insulator 20. [Figure 3] Explanatory drawing of the yoke 40. [Figure 4] Explanatory drawing of the shield ring 50. [Figure 5] View A of the impulse horn 90 in FIG. 1. [Figure 6] Graph showing the relationship between the core diameter D of the insulator 20 and the buckling load Pcr.

Mode for Carrying Out the Invention

[0016] Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory drawing of a V suspension device 1 with an impulse horn, which is an embodiment of the present invention. FIG. 2 is an explanatory drawing of the insulator 20. The enlarged view in FIG. 2 is a partially enlarged view of the cross-section obtained by cutting the insulator 20 along the central axis of the core member 25. FIG. 3 is an explanatory drawing of the yoke 40. FIG. 4 is an explanatory drawing of the shield ring 50. FIG. 5 is a view A of the impulse horn 90 in FIG. 1. In FIGS. 1 to 5, the vertical direction in the state where the V suspension device 1 with an impulse horn is attached to the tower arm 2 of the tower is defined as the up-down direction, the direction perpendicular to the up-down direction and parallel to the axial direction of the first insulator 21 and the second insulator 22 is defined as the left-right direction, and the direction perpendicular to the up-down direction and the left-right direction is defined as the front-back direction.

[0017] The V suspension device 1 with an impulse horn includes a V suspension device 10 and an impulse horn 90. The V suspension device 10 is attached between the tower arm 2 of the tower and the main line of an overhead transmission line (not shown), and is used to support the main line and insulate between the main line and the tower. As shown in FIG. 1, the V suspension device 10 includes a first insulator 21, a second insulator 22, a yoke 40, a shield ring 50, a connecting fitting 60, a ground-side horn 70, and a tower attachment fitting 80.

[0018] The first insulator 21 and the second insulator 22 are arranged so that their axial lower ends are close together, forming a V-shape. The first insulator 21 and the second insulator 22 each comprise a core member 25, an outer sheath 26, and a gripping fitting 30. The first insulator 21 and the second insulator 22 are used with their upper ends connected to the tower arm 2 and their lower ends connected to the main line. Therefore, the upper end of the first insulator 21 and the second insulator 22 is also referred to as the grounding side, and the lower end is also referred to as the energized side. In this embodiment, the first insulator 21 and the second insulator 22 have the same configuration and are arranged symmetrically. Hereafter, the first insulator 21 and the second insulator 22 will not be distinguished and will be referred to as insulator 20, and the components of insulator 20 will be described using Figures 1 and 2.

[0019] The core member 25 is an insulating rod-shaped member. Examples of materials for the core member 25 include fiber-reinforced plastic (FRP). Examples of fibers in FRP include glass fibers. Examples of plastics in FRP include epoxy resin and polyester resin. In this embodiment, the core member 25 is a solid cylindrical member, but it may also be a hollow cylindrical member. The core member 25 has a Young's modulus E of 29400 [N / mm²]. 2 It may be set to ] or higher. Young's modulus E is 39200 [N / mm²]. 2 It may be less than or equal to 35280[N / mm 2 The following is also acceptable:

[0020] The outer sheath 26 is an insulating member provided on the outer circumference of the core member 25. In this embodiment, the outer sheath 26 is configured as an elastic insulator. The outer sheath 26 is mainly composed of an insulating polymer material, and therefore the insulator 20 is configured as a polymer insulator. Specific examples of polymer materials include silicone rubber, EPDM (ethylene-propylene-diene-monomer) rubber, and EVA (ethylene-vinyl acetate), and more specifically, silicone rubber vulcanized at high temperature. The outer sheath 26 has a body portion 27 and a cap portion 28. The body portion 27 has a substantially constant diameter and is arranged to cover the outer circumferential surface of the core member 25. The cap portion 28 has a larger diameter than the body portion 27 and is formed to protrude radially outward from the outer circumferential surface of the body portion 27. Multiple cap portions 28 are arranged at intervals along the axial direction of the core member 25. In this embodiment, the multiple cap portions 28 all have the same diameter, but the multiple cap portions 28 may have multiple large-diameter cap portions and multiple small-diameter cap portions arranged alternately along the axial direction. Each of the multiple cap portions 28 has an inclined upper surface. More specifically, the upper surface of each cap portion 28 is more inclined from the direction perpendicular to the axial direction compared to the lower surface.

[0021] The gripping fitting 30 is a metal member that covers and grips both axial ends of the core member 25. The gripping fitting 30 has an upper end gripping fitting 31 that grips the upper end of the core member 25 and a lower end gripping fitting 32 that grips the lower end. Examples of materials for the gripping fitting 30 include carbon steel and ductile cast iron. The upper end gripping fitting 31 has a main body portion 33 and an upper end connecting portion 35. The lower end gripping fitting 32 has a main body portion 33 and a lower end connecting portion 36. The main body portion 33 of the upper end gripping fitting 31 and the main body portion 33 of the lower end gripping fitting 32 have the same structure and are arranged symmetrically along the axial direction of the insulator 20.

[0022] Each of the main body portions 33 of the upper gripping fitting 31 and the lower gripping fitting 32 is a cylindrical member having a bottomed insertion hole 33a formed along the central axis. The end of the core member 25 is inserted into this insertion hole 33a. A crimping portion is formed on the main body portion 33, and the gripping fitting 30 grips the core member 25 by the inner circumferential surface of the insertion hole 33a pressing against the core member 25 in the portion where the crimping portion exists. This maintains the axial tensile strength of the insulator 20 at the required value (for example, the tensile strength between the power line and the transmission tower plus a margin). Although not shown in the figure, the portion of the outer circumferential surface of the main body portion 33 where the crimping portion exists is slightly recessed compared to other portions. In other words, the portion of the main body portion 33 where the crimping portion exists has a smaller diameter (reduced diameter) compared to other portions. As shown in Figure 2, not only the end of the core member 25 but also the end of the outer sheath 26 is inserted into the insertion hole 33a of the main body portion 33.

[0023] The upper end connecting portion 35 is provided on the outer side (upper end side) in the axial direction of the insulator 20 relative to the main body portion 33 of the upper end gripping fitting 31, and constitutes the upper end of the insulator 20. The upper end connecting portion 35 is formed, for example, in the shape of a plate. The upper end connecting portion 35 is connected to the tower mounting fitting 80. Specifically, the upper end connecting portion 35 has a connecting hole 35a, and is connected to the connecting member 82 of the tower mounting fitting 80 using, for example, bolts and nuts (not shown) through this connecting hole 35a.

[0024] The lower end connecting portion 36 is provided on the outer side (lower end side) in the axial direction of the insulator 20 relative to the main body portion 33 of the lower end gripping fitting 32, and constitutes the lower end of the insulator 20. The lower end connecting portion 36 is formed, for example, in the shape of a plate. The lower end connecting portion 36 is connected to the yoke 40. Specifically, the lower end connecting portion 36 has connecting holes 36a and 36b, and is connected to the yoke 40 using, for example, bolts and nuts (not shown) through these connecting holes 36a and 36b. In this embodiment, as described above, the upper end connecting portion 35 has one hole (connecting hole 35a), and the upper end connecting portion 35 and the tower mounting fitting 80 are connected by a so-called single-point fastening. In contrast, the lower end connecting portion 36 has two holes (connecting holes 36a and 36b), and the lower end connecting portion 36 and the yoke 40 are connected by a so-called two-point fastening. Furthermore, in this embodiment, the connecting holes 36a and 36b are arranged along the axial direction of the insulator 20.

[0025] As shown in Figures 1 and 2, the first insulator 21 is configured as an integrated polymer insulator that does not have a structure in which multiple insulators are connected in the axial direction. Specifically, the first insulator 21 has one core member 25, and the first insulator 21 does not have a structure in which multiple insulators are connected in the axial direction using, for example, connecting fittings. Similarly, the second insulator 22 is configured as an integrated polymer insulator that does not have a structure in which multiple insulators are connected in the axial direction.

[0026] The V-shaped angle θ formed by the first insulator 21 and the second insulator 22, that is, the angle θ between the axial direction of the first insulator 21 and the axial direction of the second insulator 22, may be, for example, 60° or more. The angle θ may be 100° or less, 90° or less, or less than 90°.

[0027] The yoke 40 is a member connected to the lower end of the first insulator 21 and the lower end of the second insulator 22. The yoke 40 is a metal plate-shaped member and, as shown in Figure 3, has, for example, a triangular shape (including a triangular shape with rounded corners). The yoke 40 may also be trapezoidal in shape. A shield ring 50 is attached to the yoke 40. A connecting fitting 60 is also connected to the yoke 40. The yoke 40 has connecting holes 41a, 41b, 42a, 42b, mounting holes 43a to 43d, and a connecting hole 44a.

[0028] The connecting holes 41a and 41b are arranged along the axial direction of the first insulator 21 in the V-suspension device 10. The connecting hole 41a is connected to the connecting hole 36a of the lower end connecting portion 36 of the first insulator 21, and the connecting hole 41b is connected to the connecting hole 36b of the lower end connecting portion 36 of the first insulator 21, thereby connecting the lower end connecting portion 36 and the yoke 40 by two-point fastening as described above. In this way, the first insulator 21 and the yoke 40 are connected. Similarly, the connecting holes 42a and 42b are arranged along the axial direction of the second insulator 22 in the V-suspension device 10. The connecting hole 42a is connected to the connecting hole 36a of the lower end connecting portion 36 of the second insulator 22, and the connecting hole 42b is connected to the connecting hole 36b of the lower end connecting portion 36 of the second insulator 22, so that the lower end connecting portion 36 and the yoke 40 are connected by two-point fastening as described above. In this way, the second insulator 22 and the yoke 40 are connected. Mounting holes 43a to 43d are holes for attaching the shield ring 50 to the yoke 40. The connecting hole 44a is a hole for connecting the yoke 40 and the connecting fitting 60, and is located near the lower end of the yoke 40.

[0029] The shield ring 50 is, for example, a metal component and comprises a main body 51 and support parts 52-55. The main body 51 is formed in a ring shape and is positioned around the lower ends of the first insulator 21 (here, the lower end gripping fitting 32) and the second insulator 22 (here, the lower end gripping fitting 32), surrounding them. As shown in Figure 4, the main body 51 is formed in an elliptical ring shape when viewed from above, and as can be seen from Figures 1 and 4, it has a shape that deforms an ellipse so that the center on both sides is the highest and both ends on both sides are the lowest. The support parts 52-55 are rod-shaped components and are arranged to extend from the front, rear, left, and right ends of the lower surface of the main body 51 toward the center downwards of the main body 51. Two mounting holes are formed at the tip of each of the support parts 52-55, and the shield ring 50 is attached to the yoke 40 by connecting these mounting holes to the mounting holes 43a-43d of the yoke 40 with bolts and nuts. The shield ring 50 is attached to the yoke 40 so as not to come into contact with the first insulator 21 and the second insulator 22, and is positioned so that the main body 51 surrounds the lower ends of the first insulator 21 and the second insulator 22. The shield ring 50 plays a role in mitigating electric field concentration around the lower ends of the first insulator 21 and the second insulator 22. When used in conjunction with the impulse horn 90, the shield ring 50 plays a role in protecting the first insulator 21 and the second insulator 22. More specifically, when lightning strikes, flashing occurs between the shield ring 50 and the impulse horn 90, protecting the first insulator 21 and the second insulator 22 from lightning strikes. In addition, the shield ring 50 and the ground-side horn 70 can also protect the first insulator 21 and the second insulator 22 from lightning strikes.

[0030] The connecting fitting 60 is a component for connecting the V-suspension device 10 to the main line of the overhead power transmission line. The upper end of the connecting fitting 60 is connected to the connecting hole 44a of the yoke 40 by bolts and nuts, and the main line of the overhead power transmission line is attached to the lower end (not shown) and held in place by the connecting fitting 60. The main line is held in place by the connecting fitting 60 so that its axial direction is aligned with the front-rear direction. The main line held in the connecting fitting 60 may be one line or multiple lines. A main line holder (not shown) may be attached between the connecting fitting 60 and the main line to hold the main line.

[0031] The grounding horn 70 is, for example, a metal component and is attached to a tower mounting bracket 80 connected to the first insulator 21 and another tower mounting bracket 80 connected to the second insulator 22. The grounding horn 70 has a fixed base 71 and a plurality of arm portions 72 that extend radially downward from the fixed base 71 in a top view. The grounding horn 70 has, for example, four arm portions 72, two of which are shown in Figure 1. By being attached to the tower mounting bracket 80, the grounding horn 70 does not come into contact with the first insulator 21 and the second insulator 22, and the arm portions 72 are positioned around the upper ends of the first insulator 21 and the second insulator 22.

[0032] The tower mounting bracket 80 is a component for attaching the V-suspension device 10 to the lower surface of the tower arm 2. The tower mounting bracket 80 comprises a fixing member 81 which is attached to the lower surface of the tower arm 2, for example, by bolts and nuts, and a connecting member 82 which connects the fixing member 81 and the insulator 20. The V-suspension device 10 comprises two tower mounting brackets 80, and the first insulator 21 and the second insulator 22 are attached to the tower arm 2, respectively. The connecting member 82 of each of the two tower mounting brackets 80 is connected to the upper end connecting portion 35 of the first insulator 21 and the second insulator 22 using a connecting hole 35a. The fixing member 81 and the connecting member 82 are connected, for example, by bolts and nuts, and the connecting member 82 is rotatably connected to the fixing member 81 with the bolt as the axis of rotation. As a result, the part of the V-suspension device 10 excluding the fixing member 81 is rotatable in the front-rear direction.

[0033] The impulse horn 90 is attached to the lower surface of the tower arm 2 of a tower that supports an overhead power transmission line via a V-suspension device 10. The impulse horn 90 comprises a fixing member 91 and a main body 92. The fixing member 91 is attached to the lower surface of the tower arm 2 by, for example, bolts 93 and nuts. The main body 92 is a U-shaped metal member, as shown in Figure 5, for example, and is positioned to protrude downward from the fixing member 91. It is preferable that the impulse horn 90 is attached directly above the shield ring 50. It is preferable that the distance G between the shield ring 50 and the impulse horn 90 be smaller than the axial distance between the shield ring 50 and the arm portion 72 of the ground-side horn 70.

[0034] Here, the first insulator 21 and the second insulator 22 each satisfy the following equation (1) for the core diameter D [mm] and insulator length L [mm] of the core member. As shown in Figure 2, the core diameter D is the diameter of the core member 25. The insulator length L is the maximum length along the axial direction of the insulator 20, from the part at the upper end of the insulator 20 that is connected to another member to the part at the lower end that is connected to another member. In this embodiment, as shown in Figure 2, the insulator length L is the length from the center of the connecting hole 35a in the upper end connecting part 35 of the insulator 20 to the center of the connecting hole 36b in the lower end connecting part 36. As mentioned above, the insulator length L is defined to be the maximum length, so in the insulator 20 of this embodiment, the insulator length L is the length from the center of the connecting hole 35a to the center of the "connecting hole 36b", not the length from the center of the "connecting hole 36a" to the center of the "connecting hole 36a".

[0035] D 4 / L 2 >0.5883 (1)

[0036] The first insulator 21 and the second insulator 22 satisfy equation (1) with respect to the core diameter D and insulator length L, respectively, thereby suppressing buckling of the first insulator 21 and the second insulator 22 when a load is applied to the V-suspension device 10 due to the main line of the overhead power transmission line being affected by wind.

[0037] The inventors of the present invention found the formula (1) as follows. First, the horizontal load P2 [N] applied to the main line by the wind pressure was calculated by the following formula (2). The span l in formula (2) is the length of the main line between the towers (the length of the main line between the tower supporting the V suspension device 10 and another tower). "n×d / 1000×l" in formula (2) means the area of the main line receiving the wind pressure. The number n of the main lines was set to the value 1. The outer diameter d of the main line was set to 28.5 [mm] assuming an ACSR410 transmission line. The span l was set to 300 [m]. The wind pressure Pw was set to 980 [N / m 2 assuming a wind speed of 40 [m / s]. As a result, the horizontal load P2 was calculated to be 8379.0 [N].

[0038] P2 = n×d / 1000×l×Pw (2) (However, P2: Horizontal load [N] n: Number of main lines supported by the V suspension device 10 d: Outer diameter of the main line [mm] l: Span [m] Pw: Wind pressure [N / m 2 )

[0039] Next, based on the horizontal load P2, the axial compression load P2’ [N] applied to each of the first insulator 21 and the second insulator 22 was calculated by the following formula (3). The angle θ was set to 60°. As a result, the compression load P2’ was calculated to be 8379.0 [N].

[0040] P2’ = 1 / 2×P2 / sin(θ / 2) (3) (However, P2’: Compression load [N] θ: Angle [°] formed by the axial direction of the first insulator 21 and the axial direction of the second insulator 22

[0041] Also, the buckling load Pcr of each of the first insulator 21 and the second insulator 22 can be expressed as the following formula (4) using Euler's formula. The end conditions of the first insulator 21 and the second insulator 22 are rotation - rotation (both ends are rotatable), and thus the end condition coefficient C was set to the value 1. The Young's modulus E of the core member 25 was set to 29400 [N / mm2 I used ].

[0042] Pcr = C × π 2 ×E×I / L 2 =C × π 3 ×E×D 4 / (L 2 ×64) (4) (however, Pcr: Buckling load of insulator 20 [N] C: Terminal condition coefficient E: Young's modulus of core member 25 [N / mm²] 2 ] I: Second moment of area of ​​core member 25 (I=π×D) 4 / 64) D: Core diameter of core member 25 [mm] L: Insulator length of insulator 20 [mm])

[0043] Furthermore, if the buckling load Pcr is greater than the compressive load P2', the insulator 20 will not buckle even when the compressive load P2' is applied. Therefore, the conditions for Pcr > P2' were derived from equations (3) and (4) above, resulting in the following equation (5).

[0044] D 4 / L 2 >P2'×64 / (C×π 3 ×E) (5)

[0045] By substituting the values ​​of the compressive load P2', the terminal condition coefficient C, and Young's modulus E mentioned above into equation (5), we obtained equation (1). Therefore, if the first insulator 21 and the second insulator 22 satisfy equation (1) with respect to the core diameter D and the insulator length L, the buckling load Pcr will be greater than the assumed compressive load P2', thus reducing the likelihood of the first insulator 21 and the second insulator 22 buckling.

[0046] Figure 6 is a graph showing the relationship between the core diameter D of the insulator 20 and the buckling load Pcr (i.e., the relationship in equation (4)) when the insulator length L is 1085 [mm] as an example. Figure 6 also shows the straight line representing the compressive load P2' mentioned above. In this example in Figure 6, it can be seen that if the core diameter D is approximately 29 [mm] or more, the buckling load Pcr becomes larger than the compressive load P2', making the insulator 20 less likely to buckle.

[0047] The core diameter D and insulator length L only need to satisfy equation (5), but the core diameter D may be, for example, 29 mm or more, or 30 mm or more. The core diameter D may be 65 mm or less. The insulator length L may be, for example, 600 mm or more, or 900 mm or more. The insulator length L may be 4500 mm or less, 3500 mm or less, or 2500 mm or less. The insulator length L is determined by taking into consideration the resistivity of the outer sheath 26, the magnitude of the nominal voltage of the overhead transmission line supported by the V-suspension device 10, and the magnitude of the voltage that the insulator 20 should insulate, such as the lightning impulse voltage.

[0048] As mentioned above, in equation (3), the angle θ was set to 60°. As can be seen from equation (3), the compressive load P2' tends to decrease as the angle θ increases, so even if the core diameter D and insulator length L are the same, the larger the angle θ, the less likely the insulator 20 is to buckle.

[0049] As described in detail above, the V-shaped suspension device 10 of this embodiment satisfies equation (1) with respect to the core diameter D and insulator length L of the first insulator 21 and the second insulator 22, respectively, thus suppressing buckling of the first insulator 21 and the second insulator 22. Furthermore, by suppressing buckling of the first insulator 21 and the second insulator 22, lateral swaying of the main overhead power transmission line supported by the V-shaped suspension device 10 can also be suppressed.

[0050] Furthermore, by keeping the core diameter D at 65 mm or less, it is possible to prevent the gripping fittings 30 of the first insulator 21 and the second insulator 22 from becoming too large. The core diameter D may be made larger than 65 mm, thereby increasing the rigidity of the insulator 20. However, in that case, the required size of the gripping fittings 30 would increase, which would have the disadvantage of potentially making it impossible to use existing overhead line fittings (e.g., tower mounting fittings 80). Also, it goes without saying that as the core diameter D increases, the weight of the insulator 20 itself increases, which poses a disadvantage in terms of transporting the insulator 20. These disadvantages are less likely to occur if the core diameter D is 65 mm or less.

[0051] Furthermore, the first insulator 21 and the second insulator 22 each have a lower end connecting portion 36 that forms the lower end of the insulator 20 and is connected to the yoke 40 at two points. This makes it possible to suppress the rotation of the yoke 40 relative to the first insulator 21 and the second insulator 22 when a horizontal load is applied to the yoke 40 via the overhead power line due to wind pressure. For example, if the lower end connecting portions 36 of the first insulator 21 and the second insulator 22 do not have a connecting hole 36b and are connected to the yoke 40 only by a connecting hole 36a, then when a load is applied to the yoke 40 in the left-right direction, the yoke 40 will easily rotate in a plane along the up-down and left-right directions, as shown by arrow B in Figure 1. In contrast, in this embodiment, since the lower end connecting portion 36 is connected to the yoke 40 at two points by connecting holes 36a and 36b, such rotation can be suppressed. This prevents forces other than axial forces from being applied to the first insulator 21 and the second insulator 22, thereby improving the load-bearing capacity of the V-suspension device 10.

[0052] Furthermore, the V-suspension device 1 with an impulse horn comprises a V-suspension device 10 and an impulse horn 90 that can be attached to the tower arm 2 of a tower supporting an overhead power transmission line via the V-suspension device 10. The V-suspension device 10 has a shield ring 50 positioned around the lower ends of the first insulator 21 and the second insulator 22. In this way, the V-suspension device 1 with an impulse horn is equipped with an impulse horn 90 and a shield ring 50, which protects the first insulator 21 and the second insulator 22 from lightning strikes. Here, as described above, the first insulator 21 and the second insulator 22 are each configured as integrated polymer insulators that do not have a structure in which multiple insulators are connected in the axial direction. Therefore, since the first insulator 21 and the second insulator 22 do not have a connector near the axial center, an intermediate horn cannot be attached to a connector. Therefore, if the axial distance between the shield ring 50 and the arm portion 72 of the ground-side horn 70 is long, the protection of the first insulator 21 and the second insulator 22 from lightning strikes may be insufficient. In contrast, by providing the impulse horn-equipped V-suspension device 1 with the impulse horn 90, the first insulator 21 and the second insulator 22 can be protected from lightning strikes even between the impulse horn 90 and the shield ring 50, thereby improving the lightning strike resistance of the first insulator 21 and the second insulator 22.

[0053] Furthermore, since the first insulator 21 and the second insulator 22 are each constructed as integrated polymer insulators without a structure in which multiple insulators are connected in the axial direction, the first insulator 21 and the second insulator 22 can be configured without connectors near the axial center, thus reducing the weight of the first insulator 21 and the second insulator 22. In addition, with conventional magnetic insulators, there are constraints on the axial length of a single insulator due to transportation and manufacturing constraints, which often necessitates connecting multiple insulators in the axial direction. In contrast, polymer insulators have relatively few constraints on axial length, so even when the insulator length L is long, the first insulator 21 and the second insulator 22 can each be constructed as integrated structures.

[0054] It goes without saying that the present invention is not limited in any way to the embodiments described above, and can be implemented in various forms as long as they fall within the technical scope of the present invention.

[0055] For example, in the embodiment described above, the first insulator 21 and the second insulator 22 were described without distinction, assuming that their core diameter D and insulator length L were the same value. However, the core diameter D and / or insulator length L may be different for the first insulator 21 and the second insulator 22. In this case as well, it is sufficient that the core diameter D1 and insulator length L1 of the first insulator 21 satisfy the relationship in equation (1), and the core diameter D2 and insulator length L2 of the second insulator 22 satisfy the relationship in equation (1). However, it is preferable that the core diameter D1 and core diameter D2 are the same value (slight differences such as manufacturing tolerances are permitted). The same applies to the insulator length L1 and insulator length L2.

[0056] In the embodiment described above, the lower end connecting portion 36 of the first insulator 21 and the second insulator 22 were connected to the yoke 40 at two points. However, it is sufficient if the lower end connecting portion 36 of at least one of the first insulator 21 and the second insulator 22 is connected to the yoke 40 at at least two points. If the lower end connecting portion 36 of either the first insulator 21 or the second insulator 22 is connected to the yoke 40 at at least two points, the above-described effect, namely the effect of suppressing the rotation of the yoke 40 relative to the first insulator 21 and the second insulator 22 when a horizontal load is applied to the yoke 40, can be obtained. For example, the lower end connecting portion 36 of the first insulator 21 may be connected to the yoke 40 at two points, and the lower end connecting portion 36 of the second insulator 22 may be connected to the yoke 40 at one point. At least one of the lower end connecting portion 36 of the first insulator 21 and the lower end connecting portion 36 of the second insulator 22 may be connected to the yoke 40 at three or more points. Alternatively, the lower end connecting portion 36 of the first insulator 21 and the lower end connecting portion 36 of the second insulator 22 may each be connected to the yoke 40 at one point.

[0057] In the embodiment described above, one shield ring 50 surrounded the lower ends of the first insulator 21 and the second insulator 22 together. However, the V-suspension device 10 is not limited to this configuration and may have one or more shield rings. For example, instead of the shield ring 50, the V-suspension device 10 may have a first shield ring surrounding the lower end of the first insulator 21 and a second shield ring surrounding the lower end of the second insulator 22. The V-suspension device 10 does not need to have the shield ring 50. Furthermore, the V-suspension device 10 does not need to have the ground-side horn 70.

[0058] In the embodiment described above, the lower end connecting portion 36 was part of the lower end gripping fitting 32, but it is not limited to this, and the lower end connecting portion 36 and the lower end gripping fitting 32 (main body portion 33) may be separate components. The same applies to the upper end connecting portion 35 and the upper end gripping fitting 31.

[0059] In the above-described embodiment, the V-suspension device 1 with an impulse horn was described as comprising a V-suspension device 10 and an impulse horn 90. However, the embodiment may also consist of only the V-suspension device 10 without the impulse horn 90. Furthermore, the V-suspension device 1 with an impulse horn and the V-suspension device 10 were described as being attached to the tower arm 2, but they may also be described as being before attachment. [Industrial applicability]

[0060] This invention can be used in industries such as the manufacturing of V-shaped suspension devices for supporting the main lines of overhead power transmission lines, and insulators used in V-shaped suspension devices. [Explanation of Symbols]

[0061] 1 V-suspension device with impulse horn, 2 tower arm, 10 V-suspension device, 20 insulator, 21 first insulator, 22 second insulator, 25 core member, 26 outer sheath, 27 body, 28 cap, 30 gripping fitting, 31 upper end gripping fitting, 32 lower end gripping fitting, 33 main body, 33a insertion hole, 35 upper end connecting part, 35a connecting hole, 36 lower end connecting part, 36a, 36b connecting holes, 40 yoke, 41a, 41b, 42a, 42b connecting holes, 43a~43d mounting holes, 44a connecting hole, 50 shield ring, 51 main body, 52~55 support part, 60 connecting fitting, 70 ground side horn, 71 fixed base, 72 arm part, 80 81 Mounting bracket for transmission tower, 82 fixing member, 82 connecting member, 90 impulse horn, 91 fixing member, 92 main body, 93 bolt.

Claims

1. A V-shaped suspension device for supporting the main line of an overhead power transmission line, A first insulator and a second insulator are arranged such that their lower ends in the axial direction are close together to form a V shape, A yoke connected to the lower end of the first insulator and the lower end of the second insulator, Equipped with, The first and second insulators are each integral polymer insulators comprising a core member and an outer covering mainly composed of an insulating polymer material having a body portion and a plurality of cap portions, and do not have a structure in which a plurality of insulators are connected in the axial direction. The first insulator and the second insulator each satisfy the following formula (1): the core diameter D [mm] of the core member and the insulator length L [mm]. 0 4 / L 2 >05883 (1) V-hanging suspension device.

2. A V-shaped suspension device according to claim 1, The first insulator and the second insulator each have a core diameter D of 29 mm or more. V-hanging suspension device.

3. A V-shaped suspension device according to claim 1 or 2, The first insulator and the second insulator each have a core diameter D of 65 mm or less. V-hanging suspension device.

4. A V-shaped suspension device according to claim 1 or 2, The angle θ between the axial direction of the first insulator and the axial direction of the second insulator is 60° or more. V-hanging suspension device.

5. A V-shaped suspension device according to claim 1 or 2, At least one of the first insulator and the second insulator has a connecting portion that forms the lower end and is connected to the yoke at at least two locations. V-hanging suspension device.

6. A V-shaped suspension device according to claim 1 or 2, An impulse horn that can be attached to a transmission tower supporting the overhead power line via the V-suspension device, Equipped with, The V-shaped suspension device has one or more shielding rings arranged around the lower end of the first insulator and the lower end of the second insulator. V-shaped suspension device with impulse horn.

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