JPH036975Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

This invention relates to a lead wire device that penetrates the case of an electrical device, and in particular improves the conductor support portion within the bushing insulator tube.

[Prior art and its issues]

Japanese Utility Model Publication No. 55-34623 discloses a lead-out wire device that prevents rainwater from entering the case of electrical equipment through capillary action through the slits in the core wires and insulation coverings outside the case of electrical equipment. It has been disclosed in the official bulletin. This lead wire device connects an internal electric wire and an external electric wire, inserts them into a through hole of a bushing insulator, and interposes a bag-shaped cap between the connected internal electric wire and external electric wire. This is intended to prevent rainwater from entering through capillary action. However, since there is no hooking part in the through hole of the bushing insulator, when the internal wire or the external wire is pulled, the wire comes out in the direction of the tension. In order to prevent this, a large amount of insulating resin filler, which is an adhesive, is filled inside the bushing insulator. However, since the resin filler and the bushing insulator have different expansion coefficients, there is a problem in that if a large amount of resin filler is filled, the bushing insulator may crack due to a sudden change in temperature. A solution to this problem is disclosed in Japanese Utility Model Publication No. 1294/1983. In this lead wire device, a resin filler is filled in a bushing insulator, a conductor, etc. passing through the bushing is fixed integrally with the bushing, a sanding part is provided in the bushing, and a sanding section is provided between the resin fillers. A buffer is interposed between the two. With this structure, the bushing insulator will not be damaged due to the action of the buffer even if it is subjected to sudden temperature changes. Furthermore, the sanding part can prevent the resin filler from shifting. However, when a tensile force is applied to the external wire during terminal connection work, the resin filler will come out of the bushing insulator along with the conductor, and the waterproof function will no longer be achieved.There is no sufficient solution to this problem. . Furthermore, in Japanese Utility Model Application Publication No. 51-136500, a rubber tube with a circular flange protruding from the core wire of a covered lead wire and an outlet fitting is fitted and connected, and a rubber tube with a protruding circular flange piece is fitted in a mold, and this rubber tube is insulated with an insulator. A waterproofing device for a lead wire insulator fitted with a lead wire insulator is disclosed. According to this device, the core wire of the lead wire and the outlet fitting are simply inserted and fitted, and if the covered lead wire is strongly pulled, it is easily removed from the outlet fitting. For this reason, the specification states that the insertion end of the rubber tube is filled with insulating material as necessary, but for the above reasons, fixing the covered lead wire by filling with insulating material is essential. . In this case, if the wire is subjected to stress during wire terminal construction or vibration or rocking due to wind and snow over many years, excessive stress may be placed on the fixed point of the wire because the wire is fixed to the insulator with an insulator. There is a problem that the core wire of the coated lead wire is easily cut due to the stress.

[Purpose of invention]

Therefore, an object of the present invention is to provide a lead wire device for electrical equipment that prevents the conductor and resin filler from coming out of the bushing insulator even when a tensile force is applied to the wire during terminal connection work, etc. It is in. Another purpose of the present invention is to obtain a stable holding force for the wire by moving the part where the wire is exposed from the packing away from the connecting part between the conductor and the wire, and to make it easier to hold the wire during wire terminal work. It is an object of the present invention to provide a lead wire device for electrical equipment that prevents wire breakage due to stress and vibrations and rocking due to wind and snow over many years.

[Structure of the idea]

By the way, there is generally a large variation in the finished dimensions of bushing insulators. If the packing has enough compression allowance to hold the wire for the largest diameter within the variation range, the compression allowance will be too large for wires close to the minimum diameter within the variation range. Put it away. Therefore, the axial length of the packing is long and the amount of compression is large, making assembly and insertion difficult. Even if it is assembled by force, the stress applied to the bushing insulator becomes excessive, and there is a risk that the bushing insulator will be destroyed due to deterioration of the packing or cold/heat cycle. On the other hand, if the compression allowance of the packing is made small, there will be a problem that the packing compression allowance will be insufficient near the maximum diameter of the variation in the inner diameter of the bushing insulator, and the holding force of the electric wire will become unstable and the resistance to pullout will become small. Therefore, in the present invention, in a bushing insulator tube in which a conductive part equipped with a packing is inserted, the through hole of the bushing insulator tube is formed with a small diameter part and a large diameter part, and the small diameter part and the large diameter part are formed in the through hole of the bushing insulator pipe. The large-diameter portion communicates with each other via a stepped portion, and the conductive portion connects the internal conductor with the core wire of an external wire having a smaller diameter than the small-diameter portion, and the connecting portion is caulked to connect the conductive portion to the conductive portion. The wire is integrally formed to prevent the wire from coming out, and a play space is provided between the small diameter portion and the external wire, and the gasket holds the connecting portion and connects the wire formed in the through hole. The packing is in pressure contact with the stepped portion, and furthermore, an extension portion is formed in the packing beyond the stepped portion toward the small diameter portion, and the extended portion consists of a small diameter portion and a large diameter portion, and the small diameter portion is The diameter is smaller than the small diameter part of the through hole, and the large diameter part is larger than the small diameter part of the through hole, and the gap between the bushing insulator and the internal conductor is filled with insulating resin. The inner conductor is filled with a deformed portion and the large diameter portion is sanded. In the present invention, the term conductor refers to an electrically conductive material used to carry electric current, including electric wires.

【Example】

The present invention will be explained in more detail based on embodiments shown in the drawings. FIG. 1 is a sectional view showing one embodiment. The bushing insulator 1 has a collar 2 for attachment to a case C. In the figure, the left side 3 of the collar 2 is located inside the case C, and the right side 4 projects outside the case C. The bushing insulator 1 has a through hole 5 passing through it in the axial direction. The through hole 5 extends to the right from the center through the small diameter portion 5a and reaches the right opening 5b. It is formed to the left of the central step portion 5c through an intermediate diameter portion 5d, a diagonal step portion 5e, and a large diameter portion 5f, which widens toward the end and reaches the left opening 5g. A sanding portion 6 is provided on the inner surface at the back of the large diameter portion 5f. A conductive portion 7 passes through the through hole 5 of the bushing insulator 1. The conductive portion 7 includes an internal conductor 8 located to the left of the center and an external wire 9 located to the right. An insertion hole 8a is provided at the right base end of the internal conductor 8. The left proximal end of the external electric wire 9 has its covering removed to expose a core wire 9a slightly longer than the depth of the insertion hole 8a. Then insert the core wire 9a into the insertion hole 8.
a, and this inserted portion is crimped and caulked to provide a caulked portion 10. As a result, even if rainwater or the like flows down the electric wire due to capillary action, it is blocked and does not enter the case C. The tip of the internal conductor 8 is led out of the bushing insulator 1 and connected to the internal mechanism. Further, a deformed portion 8b compressed and pressed is provided in a part of the internal conductor 8 to prevent rotation with the resin filler 11. 5h is an idle space between the external electric wire 9 and the external electric wire 9. The external electric wire 9 is led out from the opening 5b of the bushing insulator, and its tip 9b is connected to the external electric wire. Reference numeral 12 denotes a gasket for maintaining airtightness in the left-right direction along the conductive portion 7, and is inserted into the bushing insulator 1 from the left opening 5g. The outer surface of the packing 12 is connected to the inner surface of the bushing insulator 1, and also to the inner surface of the packing 12.
The inner surface of the conductive portion 2 is fitted onto the outer surface of the conductive portion 7 with a compression allowance. This patchkin 1
Caulking part 1 of external wire 9 and internal conductor 8 on the inner surface of 2
0 and maintains the space between the conductive portion 7 and the inner surface of the bushing insulator 1 in an airtight state. The stepped portion 5c catches the packing 12 when the conductive portion 7 is inserted, positions it, and prevents the conductor from slipping out. The gap on the left side of the packing 12 is the large diameter portion 5f.
The resin filler 11 is filled up to nearly 5g of the opening. This filling covers the deformed portion 8b and the sanded portion 6 of the internal conductor 8, thereby making it possible to prevent rotation between the conductive portion 7 and the bushing insulator 1. An extension portion 12a having a smaller diameter than the small diameter portion 5a is provided on the outer wire 9 side of the packing 12. This extension portion 12a is provided with an annular protrusion 12b which is a bulged portion having a larger diameter than the small diameter portion. The annular projection 12b has rounded corners to facilitate insertion. The compression amount can also be changed depending on the part. For example, the compression allowance at the proximal end of the extension is made larger and becomes smaller toward the distal end. In this case, extension 1
By making the diameter of the base part 2a larger and the diameter part of the tip part smaller, the elasticity increases rapidly as the amount of compression increases, and the packing effect becomes larger. Furthermore, if the diameters of the base and the tip are made substantially the same, the degree of increase in elasticity will be moderate depending on the amount of compression. The shape of this bulging portion may be selected depending on the size of the compression allowance and the degree of variation in the inner diameter of the bushing insulator 1. According to this embodiment, stress can be prevented from being applied to the base end of the insulated wire by the extension portion 12a. FIG. 2 shows another example of the shape of the bulge.
In FIG. 2a, the bulge has a circular arc shape or a single peak close to the arc shape. In Figure 2b, the bulge is mid-high and has two low peaks on both sides. FIG. 2c shows an example in which the bulge is thread-shaped. FIG. 2d shows a waveform in which the bulge has a crest shape. In Fig. 2e, the unevenness is triangular, and various other shapes similar to this are possible. It should be noted that the present invention is not limited to the illustrated embodiment, and many modifications can be made within the scope of the claims of the utility model registration.

[Effect of the idea]

The present invention has the above configuration and has the following effects. (1) The packing is in pressure contact with the stepped part formed in the through hole, so even if a pulling force is applied to the external wire during terminal connection work, the internal conductor and resin filler will not come out of the bushing insulator. It's either not there or it's hard to come out. In addition, the large-diameter side of the packing is filled with a resin filler, and since this filling covers the deformed part and sanding part of the internal conductor, it is possible to prevent rotation between the conductive part and the bushing insulator. ing. (2) The packing has an extension on the external wire side. As a result, the part where the external wire is exposed from the packing is moved away from the connecting part between the internal conductor and the external wire, so a stable holding force can be obtained for the external wire, and it is possible to prevent stress during wire terminal construction and damage caused by wind and snow over many years. Wire breakage due to vibration or rocking can be prevented. (3) The packing has an extension part formed toward the small diameter part, and the extension part consists of a small diameter part and a large diameter part,
The small diameter portion is formed to be smaller in diameter than the small diameter portion of the through hole,
The large diameter portion is formed to have a larger diameter than the small diameter portion of the through hole. This portion can absorb variations in the inner diameter of the bushing insulator and prevent excessive stress from being applied to the bushing insulator. (4) The diameter of the external electric wire is smaller than the small diameter part of the bushing insulator, and there is a play space between the small diameter part and the external electric wire. Therefore, even if there is stress during wire terminal construction and vibrations and swings due to wind and snow over many years, the play space will alleviate it and prevent excessive stress from being applied to the external wires. can be prevented from being cut.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view showing one embodiment of the present invention, and FIG. 2 is an explanatory view showing various examples of the packing extension. 1: Bushing insulator, 5: Through hole, 5a: Small diameter part, 5c: Center step part, 5d: Intermediate diameter part, 5f: Large diameter part, 8: Conductor, 9: External electric wire, 11: Resin filler, 12 : Patchkin, 12a: Patchkin extension part,
12b: Annular process.

Claims (1)

[Scope of Claim for Utility Model Registration] In the bushing insulator 1 in which the conductive part 7 with the packing 12 attached is inserted, the through hole 5 of the bushing insulator 1 has a small diameter part 5a.
and a large diameter portion 5f are formed, and the small diameter portion and the large diameter portion communicate with each other via step portions 5c and 5e.
The core wire 9a of the external wire 9 having a smaller diameter than that of the outer wire 9 is inserted and connected, and this connecting portion is caulked to prevent the core wire from coming out. A play space 5h is provided in between, and the gasket 12 holds the connecting portion and is in pressure contact with the stepped portion formed in the through hole 5. An extension part 12a is formed toward the small diameter part, and the extension part consists of a small diameter part and a large diameter part.The small diameter part is formed to have a smaller diameter than the small diameter part of the through hole 5, and the large diameter part is formed to have a larger diameter than the small diameter portion of the through hole, and the gap between the bushing insulator 1 and the internal conductor 8 is filled with an insulating resin filler 11. A lead wire device for electrical equipment, characterized in that a deformed portion 8b and a sanding portion 6 are formed in a large diameter portion 5f.