JP7697322B2 - Support insulator - Google Patents

Description

The present invention relates to a support insulator that supports high-voltage equipment.

The support insulator disclosed in Patent Document 1 is known as a support insulator that electrically insulates various devices made of switchboards and high-voltage conductors. The support insulator in Patent Document 1 has insert metal parts that face inward of the insulator body on the upper and lower end faces of the insulator body made of resin. The insert metal parts have threaded holes into which bolts are screwed.

In the support insulator of Patent Document 2, a single metal insert is provided at the center of the upper part of the insulator body, which is circular when viewed from above. In Patent Document 2, the insulator body includes an outer periphery forming a cylindrical outer surface, an inner periphery formed concentrically with the outer periphery and holding the metal insert, and multiple ribs formed between the inner periphery and the outer periphery. The multiple ribs are provided radially from the inner periphery toward the outer periphery, and are formed at equal angles and parallel to the radial direction of the outer periphery.

JP 2007-280712 A International Publication No. 2019/165627

In the support insulators of Patent Documents 1 and 2, there is only one insert metal part at the end of the insulator body. However, there is a need for support insulators with multiple insert metal parts arranged side by side for reasons such as improving the support strength of various devices. The inventor has invented a new support structure using ribs to meet such needs and to stably support multiple insert metal parts in a well-balanced manner.

The present invention was made in consideration of these points, and aims to provide a support insulator that can stably and balancedly support multiple insert metal parts.

The support insulator of the present invention is a support insulator comprising a body portion formed of resin and extending along a predetermined linear extension direction, and an insert metal portion embedded in the end of the body portion in the extension direction, and a plurality of the insert metal portions are provided at at least one of both ends of the body portion in the extension direction, and the body portion comprises a roughly cylindrical tubular body forming the outer periphery of the end in the extension direction, a holder provided inside the tubular body and holding the insert metal portion, and a rib extending inward from the inner periphery of the tubular body to support the holder, and at the end where the plurality of insert metal portions are provided, the holders are provided at roughly equal angles around the central axis when viewed from the central axis direction of the tubular body, and a plurality of the ribs are provided for each of the holders, and the plurality of ribs include a pair of first connection ribs that connect the space between the holders adjacent to each other around the central axis to the inside of the tubular body, and a second connection rib that connects the holder and the inside of the tubular body between the pair of first connection ribs.

According to the present invention, the holder that holds the insert metal part can be supported by a pair of first and second connection ribs. This allows multiple holders to be formed side by side at the end of the main body, and each holder can be supported by ribs in at least three locations. The rigidity of the main body can be ensured by the cavities formed by each connection rib, holder, and cylindrical body. Therefore, even if an external force is applied to the support insulator, the multiple insert metal parts held by the holder can be supported stably and in a well-balanced manner.

FIG. 2 is a front view of a supporting insulator according to the embodiment. FIG. FIG. 4 is a cross-sectional view taken along line AA in FIG. 2 and FIG. 3. 4 is a cross-sectional view taken along line BB in FIG. 2 and FIG. 3.

The following describes in detail the embodiments of the present invention with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments described below, and can be modified as appropriate without departing from the spirit of the invention. For the sake of convenience, some components may be omitted from the following figures. In the following description, unless otherwise specified, "upper", "lower", "left", "right", "front" and "rear" refer to the directions indicated by the arrows in each figure. However, the orientation of each component in each of the following embodiments is merely an example, and can be changed to any orientation.

Figure 1 is a front view of a support insulator according to an embodiment. Figure 2 is a bottom view of the support insulator, and Figure 3 is a plan view of the support insulator. As shown in Figure 1, the support insulator 10 has a main body portion 11 that extends in the up-down direction, which is the extension direction of a predetermined straight line. As shown in Figures 2 and 3, the support insulator 10 further has a plurality of insert metal portions 12 embedded in both the lower end portion 11A and the upper end portion 11B of the main body portion 11. As shown in Figure 2, four (multiple) insert metal portions 12 are provided at the lower end portion 11A of the main body portion 11, and as shown in Figure 3, two (multiple) insert metal portions 12 are provided at the upper end portion 11B of the main body portion 11.

The support insulator 10 is installed, for example, along a metal plate of various devices such as a switchboard or a specified base surface, and is fixed by inserting a fastening member such as a bolt through a through hole in the metal plate and screwing it into the female threaded hole 12a (see Figure 4) of the insert metal part 12. By fixing in this way, various devices such as a switchboard can be supported on the specified base surface via the support insulator 10.

The main body 11 can be formed from an electrically insulating thermosetting resin or a thermoplastic resin. In this embodiment, the main body 11 is formed by injection molding a resin material mixed with a thermoplastic resin as a base. Such resin materials will be described later.

On the outer surface of the main body 11, multiple caps 11C are formed between the lower end 11A and the upper end 11B, forming a wave-like shape with repeated projections and recesses.

2, the configuration of the lower end 11A of the main body 11 will be described. At the lower end 11A, the main body 11 includes a generally cylindrical lower tubular body (tubular body) 21 that forms the outer periphery of the lower end 11A, a generally cylindrical lower retainer (retainer) 22 that is provided inside the lower tubular body 21 and holds the insert metal part 12, and a plurality of ribs 23 that extend inward from the inner periphery of the lower tubular body 21 and support the lower retainer 22. At the lower end 11A of the main body 11, the lower retainer 22 is formed at four locations, and each lower retainer 22 holds one insert metal part 12. Thus, four insert metal parts 12 are held at the lower end 11A of the main body 11.

In FIG. 2, the symbol "C1" indicates the central axis C1 of the lower cylindrical body 21, and when viewed from below in the central axial direction of the lower cylindrical body 21 (as shown in FIG. 2), the lower holders 22 are provided at approximately equal angles, approximately every 90°, around the central axis C1 of the lower cylindrical body 21. In this embodiment, four lower holders 22 are provided on both the front and rear sides and the left and right sides of the central axis C1 of the lower cylindrical body 21. The lower holders 22 adjacent to each other around the central axis C1 of the lower cylindrical body 21 are formed in a series so as to be connected to each other. Therefore, for example, the lower holder 22 located on the right side is connected to the front lower holder 22 and the rear lower holder 22 adjacent to each other around the central axis C1 of the lower cylindrical body 21.

At the lower end 11A of the main body 11, the structure of the lower holder 22 and the ribs 23 are arranged in a similar manner, with the same structure being repeated approximately every 90° around the central axis C1 of the lower cylindrical body 21. Therefore, hereinafter, for the lower end 11A, the lower holder 22 located on the right side and the rib 23 connected to the lower holder 22 will be described, and descriptions of similar structures relating to the other lower holders 22 and ribs 23 will be omitted.

Multiple (four in this embodiment) ribs 23 are provided on the lower retainer 22 located on the right side. The four ribs 23 include a pair of first connection ribs 25 and a pair of second connection ribs 26.

A pair of first connection ribs 25 are provided on both the front and rear sides of the lower retaining body 22 to connect the lower retaining body 22 to the inside of the lower cylindrical body 21. Specifically, one end of the front first connection rib 25 is connected to the connection portion between the right lower retaining body 22 and the front lower retaining body 22. The front first connection rib 25 extends approximately parallel to the radial direction of the lower cylindrical body 21 and the other end is connected to the inner surface of the lower cylindrical body 21. The rear first connection rib 25 is connected to the connection portion between the right lower retaining body 22 and the rear lower retaining body 22. The rear first connection rib 25 extends approximately parallel to the radial direction of the lower cylindrical body 21 and the other end is connected to the inner surface of the lower cylindrical body 21.

The pair of second connection ribs 26 are provided between the pair of first connection ribs 25 described above, and connect the right side surface of the lower retaining body 22 to the inside of the lower cylindrical body 21.

The first connection rib 25 and the second connection rib 26 connected to the right-side lower retainer 22 are formed symmetrically in the front-rear direction. In other words, in FIG. 2, an imaginary line L1 passing through the central axis C1 of the lower cylindrical body 21 and the central axis C2 of the lower retainer 22 extends in the left-right direction, and the first connection rib 25 and the second connection rib 26 are disposed symmetrically with respect to the imaginary line L1.

In addition, in FIG. 2, two cavities S1 are formed adjacent to the lower holder 22 on the right side, surrounded by the lower holder 22, the first connecting rib 25, the second connecting rib 26, and the lower cylindrical body 21. The two cavities S1 are also formed symmetrically in the front-to-back direction.

Here, the two cavities S1 are each formed in a roughly rectangular shape, and one of the two interior angles formed near the lower holder 22 is an acute angle, and the other is an obtuse angle. Specifically, in cavity S1, the interior angle between the lower holder 22 and the first connection rib 25 is an acute angle, and the interior angle between the lower holder 22 and the second connection rib 26 is an obtuse angle.

The first connection rib 25 and the second connection rib 26, which form the same right-side cavity S1, are formed to different lengths and are arranged approximately parallel to each other. At least one of the first connection rib 25 and the second connection rib 26, which are approximately parallel, is non-parallel to the radial direction of the lower cylindrical body 21. In this embodiment, as described above, the first connection rib 25 is parallel to the radial direction of the lower cylindrical body 21, and the second connection rib 26 is oriented in a direction inclined relative to the radial direction of the lower cylindrical body 21 at its formation position, and is non-parallel to the radial direction of the lower cylindrical body 21.

In the roughly rectangular cavity S1, an arch-shaped structure ST1 (represented by a lattice pattern in FIG. 2) is formed by the lower cylindrical body 21, the first connecting rib 25, and the second connecting rib 26 that form the cavity S1. In addition, an angle-shaped structure ST2 (represented by a dot pattern in FIG. 2) is formed by the lower support body 22 and the first connecting rib 25 that form the cavity S1.

Four first connection ribs 25 and eight second connection ribs 26 are provided over the entire lower end 11A of the main body 11, and each first connection rib 25 is provided at the boundary position of adjacent lower holders 22 around the central axis C1 of the lower cylindrical body 21. Therefore, one first connection rib 25 is provided on each of the adjacent lower holders 22.

3, the configuration of the upper end 11B of the main body 11 will be described. At the upper end 11B, the main body 11 includes an approximately cylindrical upper tubular body (tubular body) 31 that forms the outer periphery of the upper end 11B, an approximately cylindrical upper retainer (retainer) 32 that is provided inside the upper tubular body 31 and holds the insert metal part 12, and a plurality of ribs 33 that extend inward from the inner periphery of the upper tubular body 31 and support the upper retainer 32. At the upper end 11B of the main body 11, the upper retainer 32 is formed in two places, and each upper retainer 32 holds one insert metal part 12. Thus, two insert metal parts 12 are held at the upper end 11B of the main body 11.

The central axis C1 of the upper cylindrical body 31 is in the same position as the central axis C1 of the lower cylindrical body 21 (see FIG. 2). In FIG. 3, when viewed from above in the direction of the central axis of the upper cylindrical body 31 (as shown in FIG. 3), the upper holders 32 are provided at approximately equal angles about the central axis C1 of the upper cylindrical body 31, approximately every 180°. In this embodiment, the two upper holders 32 are provided on both the left and right sides of the central axis C1 of the upper cylindrical body 31. The two upper holders 32 are provided at a predetermined interval on the left and right, and the front end portions and rear end portions are connected to each other by a pair of connecting ribs 34.

At the upper end 11B of the main body 11, the structures of the upper holder 32 and the ribs 33 are provided symmetrically. Therefore, below, the upper holder 32 located in the right half of the upper end 11B in FIG. 3 and the ribs 33 connected to the upper holder 32 will be described, and a description of the similar structures for the upper holder 32 and ribs 33 in the left half will be omitted.

Multiple (six in this embodiment) ribs 33 are provided on the upper retainer 32 located on the right side. The six ribs 33 include the pair of connecting ribs 34 described above, a pair of first connecting ribs 35, and a pair of second connecting ribs 36.

A pair of first connection ribs 35 are provided on both the front and rear sides of the upper retainer 32, connecting the upper retainer 32 to the inside of the upper cylindrical body 31. Specifically, one end of the front first connection rib 35 is connected to the connection between the right upper retainer 32 and the front connecting rib 34. The front first connection rib 35 extends approximately parallel to the radial direction of the upper cylindrical body 31, and the other end is connected to the inner surface of the upper cylindrical body 31. The rear first connection rib 35 is connected to the connection between the right upper retainer 32 and the rear connecting rib 34. The rear first connection rib 35 extends approximately parallel to the radial direction of the upper cylindrical body 31, and the other end is connected to the inner surface of the upper cylindrical body 31.

The pair of second connection ribs 36 are provided between the pair of first connection ribs 35 described above, and connect the front and rear surfaces of the upper retainer 32 to the inside of the upper cylindrical body 31.

The connecting rib 34, the first connecting rib 35, and the second connecting rib 36 connected to the upper retaining body 32 on the right side are formed symmetrically in the front-to-rear direction. In other words, in FIG. 3, an imaginary line L2 passing through the central axis C1 of the upper cylindrical body 31 and the central axis C3 of the upper retaining body 32 extends in the left-to-right direction, and the connecting rib 34, the first connecting rib 35, and the second connecting rib 36 are arranged symmetrically with respect to the imaginary line L2.

In addition, in FIG. 3, two cavities S2 are formed on both the front and rear sides of the right-side upper retainer 32, surrounded by the upper retainer 32, the first connecting rib 35, the second connecting rib 36, and the upper cylindrical body 31. The two cavities S2 are also formed symmetrically in the front and rear directions.

Here, the two cavities S2 are each formed in a roughly rectangular shape, and one of the two interior angles formed near the upper retainer 32 is an acute angle, and the other is an obtuse angle. Specifically, in cavity S2, the interior angle between the upper retainer 32 and the first connection rib 35 is an acute angle, and the interior angle between the upper retainer 32 and the second connection rib 36 is an obtuse angle.

The first connection rib 35 and the second connection rib 36, which form the same cavity S2, are formed to have different lengths. The second connection rib 36 is oriented in a direction that is inclined relative to the radial direction of the upper cylindrical body 31 at the position where it is formed, and is not parallel to the radial direction of the upper cylindrical body 31.

In the roughly rectangular cavity S2, an arch-shaped structure ST3 (represented by a lattice pattern in FIG. 3) is formed by the upper cylindrical body 31, the first connecting rib 35, and the second connecting rib 36 that form the cavity S2. In addition, an angle-shaped structure ST4 (represented by a dot pattern in FIG. 3) is formed by the upper support body 32 and the first connecting rib 35 that form the cavity S2.

Here, the upper end 11B of the main body 11 further includes a pair of auxiliary support ribs 38. The auxiliary support ribs 38 extend from the middle of the extension direction of the connecting rib 34 in a direction approximately parallel to the radial direction of the upper cylindrical body 31 and are connected to the inner surface of the upper cylindrical body 31.

As shown in Figures 2 and 3, in addition to the above-mentioned cavities S1 and S2, cavities S0 of various shapes are formed in the lower end 11A and upper end 11B of the main body 11. The cavity S0 in the lower end 11A is formed surrounded by the lower cylindrical body 21, the lower holder 22, and the ribs 23, and the cavity S0 in the upper end 11B is formed surrounded by the upper cylindrical body 31, the upper holder 32, and the ribs 33.

Figure 5 is a cross-sectional view of line B-B in Figures 2 and 3. As shown in Figure 5, a wall portion 40 is formed in the center, which is part of the vertical direction of the main body portion 11, and is located along a surface direction that intersects with the vertical direction. The wall portion 40 is connected to the formation surface of the cavities S0, S1, and S2 in the main body portion 11 that extends in the vertical direction, and is provided so as to protrude horizontally from the formation surface. The wall portion 40 separates the cavity S1 formed in the lower end portion 11A of the main body portion 11 from the cavities S0 and S2 formed in the upper end portion 11B, and they are not allowed to penetrate each other.

By forming the wall portion 40, the surface forming the cavities S0, S1, and S2 is no longer a surface that extends parallel in the vertical direction over the entire range from both the upper and lower ends of the main body 11, and the wall portion 40 is formed in a part of the vertical direction. This makes it possible to suppress creeping discharge between the conductor connected to one side of the main body 11 in the vertical direction and the ground side connected to the other side.

The resin material from which the main body 11 is formed will now be described. In this embodiment, the main body 11 is formed from a resin material using a thermoplastic resin with excellent insulating and heat-resistant properties. By using a thermoplastic resin for the main body 11, it is possible to eliminate the hardening reaction that occurs during molding when a thermosetting resin is used. This allows the insert metal portion 12 to be easily separated from the main body 11 by heat treatment when disposing of the product after use, thereby improving recyclability. In addition, by using a thermoplastic resin, it is possible to use an injection molding method that does not require the secondary hardening reaction that occurs when a thermosetting resin is used, and it is possible to improve the productivity of the support insulator 10.

The thermoplastic resin used for the main body 11 can be any of polybutylene terephthalate, polyethylene terephthalate, polyamide, polycarbonate, polyphenylene sulfide, and modified polyphenylene ether. By using these, it is possible to improve productivity while maintaining good insulation and heat resistance of the main body 11. In addition, by raising the temperature to a melting temperature of about 200°C, the main body 11 and the insert metal part 12 can be easily separated and reused or disposed of, thereby improving recyclability.

When forming the main body 11, a resin material based on a thermoplastic resin and mixed with an inorganic material may be used, and examples of the inorganic material include at least one of glass fiber, silica, alumina, boehmite, and talc. By using such an inorganic material, it is possible to improve recyclability and productivity without reducing the mechanical properties of the resin, such as the linear expansion coefficient and elastic modulus.

In addition, in the main body 11, the thicknesses of the lower cylindrical body 21, the retaining body 22, and the rib 23 at the lower end 11A, and the cavity S0 at the upper end 11B, the upper cylindrical body 31, the upper retaining body 32, and the rib 33 are preferably set to 10 mm or less, and more preferably set to 2 mm or more and 6 mm or less. If the thicknesses are greater than the above range, voids are likely to occur during molding by injection molding, and electrical performance such as partial discharge may be reduced during use.

In more detail, the thicker the main body 11 is during injection molding, the more likely it is that voids will occur within the thickness of the main body 11, since the molten resin is pulled toward the outer surface due to thermal contraction when the resin cools. Voids are the source of partial discharges, and the larger the voids are, the lower the electric field at which partial discharges occur; therefore, the smaller the voids, the less likely partial discharges are to occur. In this embodiment, by setting the thickness of the main body 11 within the above range, it is possible to achieve good mechanical strength as the support insulator 10, while reducing or eliminating voids to make partial discharges less likely to occur, and thereby achieving sufficient voltage resistance and electrical performance.

According to this embodiment, even if there are four lower holders 22 at the lower end 11A of the main body 11, each lower holder 22 can be supported at four positions by a pair of first connection ribs 25 and a pair of second connection ribs 26. Moreover, cavities S1 and S0 are formed by each connection rib 25, 26, the lower cylindrical body 21, and the lower holder 22, and mechanical strength can be excellently exhibited.

In addition, there are two upper retaining bodies 32 at the upper end 11B of the main body 11, and each upper retaining body 32 can be supported from four positions by a pair of first connecting ribs 35 and a pair of second connecting ribs 36. Furthermore, cavities S2 and S0 are formed by the ribs 33 such as the connecting ribs 35, 36, the upper cylindrical body 31, and the upper retaining body 32, and mechanical strength can be excellently exhibited. In this way, even if there are multiple lower retaining bodies 22 and upper retaining bodies 32, it is possible to suppress a decrease in strength compared to when there is a single one, and the multiple insert metal parts 12 held by the lower retaining body 22 and upper retaining body 32 can be stably and balancedly supported.

The support insulator 10 must be strong enough to withstand the electromagnetic force generated by currents during short-circuit accidents, etc., which can reach several thousand Newtons. Such loads act in the shear direction (for example, to the right at the lower end 11A and to the left at the upper end 11B, as shown by the arrows in Figure 1). The connecting ribs 25, 26, 35, 36 and the cavities S1, S2, S0 can distribute and exert the force against bending and flexural deformation in various locations against such shear loads, thereby providing durability in terms of strength.

Furthermore, in the main body 11, the first connection rib 25 and the second connection rib 26 are arranged symmetrically with respect to the imaginary line L1 at the lower end 11A, and the first connection rib 35 and the second connection rib 36 are arranged symmetrically with respect to the imaginary line L2 at the upper end 11B. This allows the connection ribs 25, 26, 35, and 36 to be arranged in a well-balanced manner with respect to each of the retaining bodies 22 and 32 when viewed from the central axis C1 side, and all of the retaining bodies 22 and 32 can be stably supported.

In addition, in the main body 11, an arch-shaped structure ST1 and an angle-shaped structure ST2 are formed at the lower end 11A surrounding the cavity S1, and an arch-shaped structure ST3 and an angle-shaped structure ST4 are formed at the upper end 11B surrounding the cavity S2. As a result, when a load is applied in the shear direction, one of the structures ST1 to ST4 can effectively exert a resistance against the load depending on the direction of the load, and sufficient durability can be obtained.

In this way, by making it possible for the main body 11 to effectively exert resistance against the load, it is possible to ensure strength even if the thickness of each component is reduced. In other words, since it is possible to achieve a thin thickness while still exerting good strength, it is possible to suppress the generation of voids within the thickness during injection molding, making it difficult for partial discharge to occur, and enabling voltage resistance to be exerted.

The present invention is not limited to the above embodiment, and can be modified in various ways. In the above embodiment, the size, shape, orientation, etc. shown in the attached drawings are not limited to these, and can be modified as appropriate within the scope of the effects of the present invention. In addition, the present invention can be modified as appropriate without departing from the scope of the purpose of the present invention.

For example, in the main body 11, multiple insert metal parts 12 are provided at both the lower end 11A and the upper end 11B, but it is also possible to provide a single insert metal part 12 at either the lower end 11A or the upper end 11B, or to provide no insert metal part 12 at all.

Furthermore, it is not necessary to screw fastening members such as bolts into all of the multiple insert metal parts 12 at the lower end 11A and the upper end 11B, and some of the insert metal parts 12 may be used without screwing fastening members.

Furthermore, although the main body 11 has been described as being arranged in the up-down direction, it may also be arranged in the left-right direction or the front-back direction, or in a direction inclined relative to these directions.

In addition, although a pair of second connection ribs 26, 36 have been described, one or three or more may be provided.

REFERENCE SIGNS LIST 10 Support insulator 11 Main body 11A Lower end 11B Upper end 12 Insert metal part 21 Lower cylindrical body (cylindrical body)
22 Lower holding body (holding body)
23 Rib 25 First connecting rib 26 Second connecting rib 31 Upper cylindrical body (cylindrical body)
32 Upper holding body (holding body)
33 Rib 35 First connecting rib 36 Second connecting rib 40 Wall portion C1 Central axis C2 Central axis C3 Central axis L1 Virtual line L2 Virtual line S1 Cavity S2 Cavity ST1 Arch-shaped structure ST2 Angle-shaped structure ST3 Arch-shaped structure ST4 Angle-shaped structure

Claims (9)

A main body portion formed of resin and extending in a predetermined linear direction;
an insert metal portion embedded in an end portion of the main body portion in the extending direction,
A support insulator in which a plurality of the insert metal portions are provided on at least one of both end portions in the extension direction of the main body portion,
The main body portion has a generally cylindrical tubular body that forms an outer periphery of an end portion in the extension direction,
A holder provided inside the cylindrical body and holding the insert metal portion;
a rib extending inward from an inner periphery of the cylindrical body to support the holder,
A supporting insulator characterized in that, at an end portion where a plurality of insert metal portions are provided, when the cylindrical body is viewed from the central axis direction, the retaining bodies are provided at approximately equal angles around the central axis, and a plurality of the ribs are provided for each of the retaining bodies, and the plurality of ribs include a pair of first connection ribs connecting adjacent retaining bodies around the central axis to the inside of the cylindrical body, and a second connection rib connecting the retaining body and the inside of the cylindrical body between the pair of first connection ribs. The support insulator according to claim 1, characterized in that the second connection ribs are a pair. The holder is formed in a generally cylindrical shape,
The support insulator as described in claim 1 or claim 2, characterized in that the first connection rib and the second connection rib are arranged symmetrically with respect to a virtual line passing through the central axis of the cylindrical body and the central axis of the holding body when viewed from the central axis direction. The supported insulator according to any one of claims 1 to 3, characterized in that, when the cylindrical body is viewed from the central axis direction, a cavity is formed surrounded by the cylindrical body, the holding body, the first connecting rib, and the second connecting rib, the cylindrical body forming the cavity, the first connecting rib, and the second connecting rib form an arch-shaped structure, and the holding body and the first connecting rib form an angle-shaped structure. The support insulator according to claim 4, characterized in that the first connection rib and the second connection rib forming the cavity have different lengths. The support insulator according to claim 4 or 5, characterized in that the first connection rib and the second connection rib that form the cavity are arranged approximately parallel, and at least one of them is non-parallel to the radial direction of the cylindrical body. The support insulator according to any one of claims 4 to 6, characterized in that, when the cylindrical body is viewed from the central axis direction, the cavity is formed in a roughly rectangular shape, and one interior angle closer to the holding body is an acute angle, and the other interior angle is an obtuse angle. The support insulator according to any one of claims 4 to 7, characterized in that a wall portion intersecting the extension direction is provided in a continuous manner in a portion of the extension direction of the cavity. The support insulator according to any one of claims 1 to 8, characterized in that the main body is made of a thermoplastic resin.

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