JP2024017930A - Insulator and method for manufacturing insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insulator capable of reducing the number of kinds of materials and a method for manufacturing an insulator.

SOLUTION: An insulator 1 includes : an insulator body 2 made of a synthetic resin and provided with an insertion hole 23; and a tubular member 3 in which at least one end in an axial direction is inserted into the insertion hole 23 and an outer peripheral surface is directly connected to an inner periphery surface of the insertion hole 23. Therefore, even if an adhesive layer, which is made of a material different from the material constituting the insulator body 2 and the material constituting the cylindrical member 3, does not intervene between the insulator body 2 and the cylindrical member 3, the cylindrical member 3 can be fixed to the insulator body 2. That is, the number of kinds of materials constituting the insulator 1 can be reduced.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure relates to an insulator and a method for manufacturing an insulator.

Patent Document 1 describes an insulator that covers a connection portion between an electric wire and a rod-shaped terminal fitting.
This insulator consists of a porcelain insulator body with a hollow part shaped like a through hole, a metal nut (cylindrical member) inserted into the hollow part, and an outer peripheral surface of the nut and an inner peripheral surface of the hollow part. and a cement adhesive layer interposed between the two.

The tip of the terminal fitting is provided with a hollow portion for receiving the electric wire and a male thread that is screwed into the female thread of the nut. One end of the electric wire is connected to the tip of the terminal fitting by being inserted into the hollow part of the terminal fitting. With the electric wire and the terminal fitting connected, the male thread of the terminal fitting is screwed into the female thread of the nut. As a result, the electric wire and the terminal fitting can be reliably connected, and the connection portion between the electric wire and the terminal fitting can be covered with the insulator body, which is an insulator.

Patent No. 6639944

Since the insulator described in Patent Document 1 is made of three types of materials (porcelain, metal, and cement), it is desired to reduce the number of materials that make up the insulator.

An object of the present disclosure is to provide an insulator and an insulator manufacturing method that can reduce the number of types of materials.

The insulator according to the present disclosure includes an insulator body made of synthetic resin that is provided with an insertion hole, at least one end in the axial direction is inserted into the insertion hole, and the outer peripheral surface is directly connected to the inner peripheral surface of the insertion hole. It is characterized by comprising a cylindrical member which is joined to each other.

In the present disclosure, at least one end portion of the cylindrical member in the axial direction is inserted into an insertion hole provided in the insulator body made of synthetic resin.
The outer peripheral surface of the cylindrical member is directly joined to the inner peripheral surface of the insertion hole. Therefore, the cylindrical member can be fixed to the insulator body without intervening an adhesive layer made of a material different from the material composing the insulator body and the material composing the cylindrical member between the insulator body and the cylindrical member. can do. That is, the number of types of materials that constitute the insulator can be reduced. Therefore, it is easy to procure materials and to recycle or discard the insulator after use.
Since the insulator body made of synthetic resin is lighter than the insulator body made of porcelain to which the cement adhesive layer is attached, it is possible to reduce the weight of the insulator.

The insulator according to the present disclosure is characterized in that the insulator body is made of thermoplastic resin.

In the present disclosure, the insulator body is made of thermoplastic resin.
When recycling or disposing, the insulator body can be softened or melted by heating, so the insulator can be easily disassembled.

The insulator according to the present disclosure is characterized in that a weather-resistant protective layer is provided on the surface of the insulator body.

In the present disclosure, a weather-resistant protective layer is provided on the surface of the insulator body.
Therefore, since the weather resistance of the insulator body can be strengthened, the insulator can be used for a long time even outdoors. Therefore, there is no need to frequently replace the insulator, so the environmental load can be reduced.

In the insulator according to the present disclosure, the cylindrical member is an insert nut, the other end in the axial direction of the cylindrical member is located outside the insertion hole, and the insulator body surrounds the cylindrical member. It is characterized by having a knob portion that is gripped when rotating in the direction.

In the present disclosure, the cylindrical member is an insert nut.
Generally, the outer circumferential surface of the insert nut is provided with anti-slip irregularities, so that the outer circumferential surface of the cylindrical member and the inner circumferential surface of the insertion hole can be firmly joined to each other. Therefore, when the male thread is screwed into the female thread of the cylindrical member, it is possible to prevent the cylindrical member from rotating together.
One end of the cylindrical member in the axial direction is located inside the insertion hole, but the other end of the cylindrical member in the axial direction is located outside the insertion hole, so that the operator can The position, orientation, etc. of the member can be easily grasped visually or tactilely.

The insulator body has a knob portion. By holding the knob and rotating the cylindrical member together with the insulator body, the operator can easily manually engage, for example, a male thread provided on the terminal fitting with a female thread on the cylindrical member.

A method for manufacturing an insulator according to the present disclosure is a method for manufacturing an insulator including an insulator body provided with an insertion hole, and a cylindrical member having at least one end in the axial direction inserted into the insertion hole. , a thermoplastic resin is used as the material constituting the insulator body, and before the thermoplastic resin hardens, the cylindrical member is pushed into the portion of the thermoplastic resin that is to become the insertion hole, and the thermoplastic resin is The outer circumferential surface of the cylindrical member is directly joined to the inner circumferential surface of the insertion hole by curing.

According to the present disclosure, among the insulators according to the present disclosure, those including an insulator body made of thermoplastic resin can be manufactured.
Since there is no need to inject adhesive between the insulator body and the cylindrical member, the insulator manufacturing procedure is simple, and it is possible to improve the quality of the insulator and mass-produce the insulator without relying on skilled manufacturers. can.
Since it is not necessary to use cement that hardens in a short time after being kneaded as a material constituting the insulator, the inconvenience of the kneaded cement hardening before use does not occur.

According to the insulator and the method for manufacturing the insulator of the present disclosure, it is possible to reduce the number of types of materials that make up the insulator.

1 is a partial cross-sectional view of an insulator according to Embodiment 1. FIG. FIG. 3 is a sectional view of a bushing including an insulator. It is a schematic diagram for explaining an example of the manufacturing procedure of an insulator in the case of using a thermoplastic resin. It is a schematic diagram for demonstrating another example of the manufacturing procedure of an insulator in the case of using a thermoplastic resin. It is a schematic diagram for explaining an example of the manufacturing procedure of an insulator in the case of using a thermosetting resin.

Embodiments of the present disclosure will be described below.

Embodiment 1.
FIG. 1 is a partial cross-sectional view of the insulator according to the first embodiment.
In the figure, 1 is an insulator, and the insulator 1 includes an insulator body 2 and a cylindrical member 3.
The insulator body 2 is an insulator made of synthetic resin (thermoplastic resin or thermosetting resin). The insulator body 2 integrally includes a knob portion 21 and a protrusion portion 22. The knob portion 21 has a cylindrical shape with a large diameter. The protrusion 22 has a small-diameter cylindrical shape and protrudes coaxially from one surface of the knob 21 to the knob 21. An insertion hole 23 is coaxially provided in the distal end surface of the protrusion 22 . The insertion hole 23 is a non-through hole with a circular cross section, and extends from the protrusion 22 to the knob 21. In FIG. 1, the insulator 1 is shown with the axial direction of the insulator 1 facing up and down.

Note that the knob portion 21 may have a cylindrical shape with a bottom. In this case, the protrusion 22 protrudes from the inner bottom surface of the knob 21 coaxially with the knob 21 and with the tip portion of the protrusion 22 positioned outside the knob 21. The protrusion 22 may be cylindrical. When the protrusion 22 is cylindrical, the inner side of the protrusion 22 functions as the insertion hole 23 . It is desirable that reinforcing ribs be provided so as to span the outer circumferential surface of the protruding portion 22 and the inner bottom surface and inner surface of the knob portion 21 .

The cylindrical member 3 is an insert nut, and has a flange 31 at one end in the axial direction, and has anti-slip irregularities (for example, a twilled or flattened one by knurling, not shown) on the outer peripheral surface. . The cylindrical member 3 is made of metal, for example, but is not limited thereto. The cylindrical member 3 is inserted into the insertion hole 23 such that the flange 31 is located outside the insertion hole 23. The outer peripheral surface of the cylindrical member 3 is directly joined to the inner peripheral surface of the insertion hole 23. The length of the portion of the cylindrical member 3 inserted into the insertion hole 23 in the axial direction is smaller than the depth of the insertion hole 23. There is a space at the bottom of the insertion hole 23 where the cylindrical member 3 is not present.
The insulator 1 constitutes a bushing 4 that will be described next.

FIG. 2 is a sectional view of the bushing 4 provided with the insulator 1.
The bushing 4 includes an insulator tube 41 and a terminal fitting 42 in addition to the insulator 1.
The insulator tube 41 is an insulator, and passes through a side wall of a case included in, for example, a transformer or a switch (not shown), and one end 41a of the insulator tube 41 in the axial direction is located outside the case. A notch 411 is provided in one end portion 41a of the insulator tube 41. FIG. 2 shows the vicinity of one end 41a of the bushing 4.
The inner diameter of the insulator tube 41 is larger than the outer diameter of the protrusion 22.

The terminal fitting 42 has a rod shape and passes through the insulator tube 41. At one end of the terminal fitting 42, a large-diameter disk portion 420, a small-diameter cylindrical first shaft portion 421, a large-diameter cylindrical bolt portion 422, a small-diameter cylindrical second shaft portion 423, and a large-diameter cylindrical second shaft portion 423 are provided. The connecting portions 424 are coaxially arranged in parallel in this order from one end side to the other end side. The disk portion 420 and the first shaft portion 421 are located outside the insulator tube 41. The bolt portion 422 extends inside and outside of the insulator tube 41 through the opening of the one end portion 41a. The second shaft portion 423 and the connecting portion 424 are located inside the insulator tube 41. A male thread is provided on the circumferential surface of the bolt portion 422, and this male thread corresponds to the female thread of the cylindrical member 3. The second shaft portion 423 is provided with a through hole 425 that is perpendicular to the axial direction of the second shaft portion 423 . One opening of the through hole 425 is directed toward the notch 411 of the insulator tube 41.

The electric wire 5 is a covered electric wire in which a conducting wire 51 is covered with an insulator. A conducting wire 51 is exposed at one end of the electric wire 5. The electric wire 5 is inserted into the inside of the insulator tube 41 so that the conductor wire 51 passes through the through hole 425, and is led out to the outside of the insulator tube 41 through the notch 411.

The disk portion 420 and the first shaft portion 421 are inserted into the bottom of the insertion hole 23 through the inside of the cylindrical member 3, and the bolt portion 422 is screwed into the cylindrical member 3. As a result, the conducting wire 51 is sandwiched between the flange 31 of the cylindrical member 3, the inner peripheral surface of the through hole 425, and the end surface of the connecting portion 424 closer to the bolt portion 422. As a result, the conducting wire 51 comes into contact with the second shaft portion 423 and the connecting portion 424, so that the terminal fitting 42 and the electric wire 5 are electrically connected to each other. It is desirable that a spring washer 43 and a flat washer 44 (refer to the two-dot chain lines in the figure) be interposed between the flange 31 and the conducting wire 51. The flat washer 44 is interposed between the spring washer 43 and the conductive wire 51, and the spring washer 43 biases the conductive wire 51 against the connecting portion 424 via the flat washer 44. For ease of viewing the figure, the cylindrical member 3, the connecting portion 424, the spring washer 43, the flat washer 44, and the conducting wire 51 are shown spaced apart from each other in FIG.

The insulator 1 can be attached to and detached from the terminal fitting 42. The insulator 1 can be easily attached and detached manually by an operator holding the knob 21 and rotating the insulator 1 in the circumferential direction of the knob 21. It is desirable that the circumferential surface of the knob portion 21 is provided with concavities and convexities that extend in the circumferential direction (see FIG. 1). The unevenness on the circumferential surface of the knob portion 21 functions as a non-slip when the operator grips the knob portion 21.

When threading the cylindrical member 3 and the bolt part 422 together, the operator rotates the knob part 21 and tightens the bolt part 422 with a load corresponding to the screw diameter. At this time, the protrusion 22 is inserted into the inside of the porcelain tube 41 from the opening of the one end 41a of the porcelain tube 41.
Since the connecting portion between the terminal fitting 42 and the electric wire 5 is covered by the peripheral wall of the insulator tube 41 and the insulator body 2 of the insulator 1, the connecting portion between the terminal fitting 42 and the electric wire 5 is protected from collision with foreign objects or electrical damage. It can be protected from connection etc.

It is desirable that the bushing 4 has weather resistance, especially when used outdoors. Regarding the insulator 1, since the insulator main body 2 is easily exposed to ultraviolet rays, wind and rain, etc., a weather-resistant protective layer 24 (schematically shown by a two-dot chain line in FIG. 1) is provided on the surface of the insulator main body 2. Good too. Note that the insulator body 2 itself may be made of a weather-resistant synthetic resin. When the insulator 1 has weather resistance, the insulator 1 can be used for a long time even outdoors. Therefore, there is no need to frequently replace the insulator 1, so the environmental load can be reduced.

According to the insulator 1 as described above, the outer peripheral surface of the cylindrical member 3 is directly joined to the inner peripheral surface of the insertion hole 23. Therefore, even if there is no adhesive layer between the insulator body 2 and the cylindrical member 3, which is made of a material different from the material constituting the insulator body 2 and the material constituting the cylindrical member 3, the cylindrical member 3 can be fixed to the insulator body 2. That is, the number of types of materials constituting the insulator 1 can be reduced.
Therefore, it is easy to procure materials and to recycle or discard the insulator 1 after use. In particular, when the insulator body 2 is made of thermoplastic resin, the insulator body 2 can be softened or melted by heating during recycling or disposal, so the insulator 1 can be easily dismantled.

Since the insulator body 2 made of synthetic resin is lighter than the insulator body 2 made of porcelain to which the adhesive layer made of cement is attached, the weight of the insulator 1 can be reduced. Therefore, the work of transporting the insulator 1 and the work of attaching and detaching the insulator 1 to the terminal fitting 42 are easy.
Note that the insertion hole 23 may be a through hole. In this case, the rod-shaped terminal fitting constituting the bushing 4 is inserted into one of the two openings of the insertion hole 23, and the electric wire 5 is inserted into the other (see Patent Document 1).

The cylindrical member 3 does not have to be an insert nut. However, by using an insert nut provided with anti-slip irregularities as the cylindrical member 3, the outer circumferential surface of the cylindrical member 3 and the inner circumferential surface of the insertion hole 23 can be firmly joined to each other. Therefore, when the male thread of the bolt portion 422 is screwed into the female thread of the cylindrical member 3, it is possible to prevent the cylindrical member 3 from rotating together.

Since a part of the cylindrical member 3 is located outside the insertion hole 23 as in this embodiment, the operator can easily grasp the position, orientation, etc. of the cylindrical member 3 visually or by touch. can.
The cylindrical member 3 may be configured without the flange 31. The cylindrical member 3 may be entirely inserted into the insertion hole 23. In this case, the conducting wire 51 is sandwiched between, for example, the peripheral edge of the insertion hole 23 and the connecting portion 424.

When manufacturing the insulator 1 as described above, a thermoplastic resin or a thermosetting resin is used as the material constituting the insulator body 2. When using a thermoplastic resin, before the thermoplastic resin hardens, the cylindrical member 3 is pushed into the part that will become the insertion hole 23 for the thermoplastic resin, and by hardening the thermoplastic resin, the outer periphery of the cylindrical member 3 is The surface can be directly joined to the inner peripheral surface of the insertion hole 23.

FIG. 3 is a schematic diagram for explaining an example of the manufacturing procedure of the insulator 1 when thermoplastic resin is used.
The operator injects the thermoplastic resin 20 into the mold 6 for molding the insulator body 2 (see FIG. 3A). The mold 6 has a first portion 61 corresponding to the internal space of the cylindrical member 3 and a second portion 62 corresponding to the space at the bottom of the insertion hole 23 where the cylindrical member 3 does not exist. The first portion 61 and the second portion 62 are provided integrally with each other.

Next, the operator presses the portion of the cylindrical member 3 excluding the flange 31 into the thermoplastic resin 20 before hardening (see FIG. 3B). At this time, the first portion 61 of the mold 6 is inserted inside the cylindrical member 3. When the cylindrical member 3 pushes away the thermoplastic resin 20 around the first portion 61, the insertion hole 23 is formed by the cylindrical member 3, the first portion 61, and the second portion 62.
Thereafter, by curing the thermoplastic resin 20, it is possible to obtain the insulator 1 in which the outer peripheral surface of the cylindrical member 3 is directly joined to the inner peripheral surface of the insertion hole 23.

FIG. 4 is a schematic diagram for explaining another example of the manufacturing procedure of the insulator 1 when thermoplastic resin is used.
The operator forms the insulator body 2 made of thermoplastic resin using a mold or a 3D printer (not shown) (see FIG. 4A). The formed insulator body 2 integrally has a knob portion 21 and a protruding portion 22. Furthermore, an insertion hole 23 is provided. However, the inner diameter of the insertion hole 23 is slightly smaller than the outer diameter of the cylindrical member 3.

Next, the operator pushes the portion of the cylindrical member 3 excluding the flange 31 into the insertion hole 23 before the thermoplastic resin constituting the insulator body 2 hardens (see FIG. 4B). At this time, the cylindrical member 3 is inserted into the insertion hole 23 while expanding the diameter of the insertion hole 23. Note that when the thermoplastic resin constituting the insulator body 2 is hardened, the hardened thermoplastic resin is heated to soften it, and the flange of the cylindrical member 3 is heated before the softened thermoplastic resin hardens. Push the part except 31 into the insertion hole 23.
After inserting the cylindrical member 3 into the insertion hole 23, by curing the thermoplastic resin, it is possible to obtain the insulator 1 in which the outer peripheral surface of the cylindrical member 3 is directly joined to the inner peripheral surface of the insertion hole 23. can.

FIG. 5 is a schematic diagram for explaining an example of the manufacturing procedure of the insulator 1 when using a thermosetting resin.
The operator inserts the portion of the cylindrical member 3 excluding the flange 31 into the mold 6 for molding the insulator body 2 (see FIG. 5A). At this time, the first portion 61 of the mold 6 is inserted inside the cylindrical member 3.

Next, the operator injects thermosetting resin 200 into the mold 6 (see FIG. 5B). The cylindrical member 3 inserted into the mold 6 functions, together with the first portion 61 and the second portion 62, as a mold for forming the insertion hole 23.
Thereafter, by curing the thermosetting resin 200, it is possible to obtain the insulator 1 in which the outer peripheral surface of the cylindrical member 3 is directly joined to the inner peripheral surface of the insertion hole 23.

According to the method of manufacturing the insulator 1 as described above, there is no need to inject adhesive between the insulator body 2 and the cylindrical member 3. Therefore, the manufacturing procedure of the insulator 1 is simple. Therefore, it is possible to improve the quality of the insulator 1 and mass-produce the insulator 1 without relying on a skilled manufacturer.
Since it is not necessary to use cement that hardens in a short time after being kneaded as the material constituting the insulator 1, there is no problem that the kneaded cement hardens before use.
In any of the manufacturing procedures of the insulator 1 shown in FIGS. 3 to 5, after the insulator body 2 is cured, a protective layer 24 is applied to the surface of the insulator body 2 by applying a facing paint to the surface of the insulator body 2. can be formed.

Note that when forming the insulator body 2, a temporary hole having an inner diameter larger than the insertion hole 23 may be provided at a position where the insertion hole 23 is to be formed. In this case, after the insulator body 2 has hardened, the cylindrical member 3 is inserted into the temporary hole. After inserting the cylindrical member 3, the same synthetic resin as that which constitutes the insulator body 2 is injected between the outer circumferential surface of the cylindrical member 3 and the inner circumferential surface of the temporary hole. An insertion hole 23 can be formed on the circumferential surface to which the outer circumferential surface of the cylindrical member 3 is directly joined. However, the work of injecting the synthetic resin between the outer peripheral surface of the cylindrical member 3 and the inner peripheral surface of the temporary hole is complicated. Further, care must be taken to prevent the mechanical strength of the insulator body 2 from being reduced by forming two layers, the synthetic resin cured first and the synthetic resin injected and cured later.

The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is not intended to have the above-mentioned meaning, but is intended to include meanings equivalent to the scope of the claims and all changes within the scope of the claims.
The independent and dependent claims recited in the appended claims may be combined with each other in any and all combinations, regardless of the form in which they are cited. Furthermore, although the claims are written in a format that refers to two or more other claims (multi-claim format), the invention is not limited to this format. It may be written using a multi-claim format that cites at least one multi-claim.

1 Insulator; 2 Insulator body; 20 Thermoplastic resin; 200 Thermosetting resin; 21 Knob portion; 23 Insertion hole; 24 Protective layer; 3 Cylindrical member (insert nut)

Claims (5)

A synthetic resin insulator body with an insertion hole,
An insulator comprising: a cylindrical member having at least one end in the axial direction inserted into the insertion hole, and an outer circumferential surface of which is directly joined to an inner circumferential surface of the insertion hole. The insulator according to claim 1, wherein the insulator body is made of thermoplastic resin. The insulator according to claim 1 or 2, wherein a weather-resistant protective layer is provided on the surface of the insulator body. The cylindrical member is an insert nut,
The other end of the cylindrical member in the axial direction is located outside the insertion hole,
The insulator according to claim 1 or 2, wherein the insulator main body has a knob portion that is gripped when rotating the cylindrical member in a circumferential direction. An insulator body with an insertion hole,
A method for manufacturing an insulator comprising: a cylindrical member having at least one end in the axial direction inserted into the insertion hole,
Using thermoplastic resin as a material constituting the insulator body,
Before the thermoplastic resin hardens, the cylindrical member is pushed into the portion of the thermoplastic resin that is to become the insertion hole,
A method for manufacturing an insulator, characterized in that the outer circumferential surface of the cylindrical member is directly joined to the inner circumferential surface of the insertion hole by curing the thermoplastic resin.

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