JPH0341452Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention relates to the structure of a joint of an insulated tube that surrounds and insulates a lead wire that is separated and rejoined during transportation. As electrical appliances become larger, transportation limitations require them to be transported in pieces and reassembled at the installation site. In this case, it is desirable that the reassembly work be carried out in as short a time as possible from the viewpoint of the problem of insulator moisture absorption and shortening of work time.

[Prior art and its problems]

FIG. 2 is a diagram showing an example of the structure of a conventional electrical appliance, in which the electrical appliance 21 is transported by removing the portions protruding from the transportation limit 24, such as the pocket 23 for the bushing 22. Generally, a flexible electric wire is used as the lead wire 25 that connects the winding (not shown) and the bushing 22, and this lead wire 25 is connected to an insulating tube 26 on the bushing side and an insulating tube 27 on the winding side, which can be separated and joined to each other.
penetrate inside. And the insulation tube 26 on the bushing side
The lead wire 25 is pulled out and sent separately from the electric appliance 21, and the pulled out lead wire 25 is stored inside the electric appliance 21 and transported. When reassembling at the installation site, the insulating tube 26 on the bushing side and the insulating tube 27 on the winding side, which have been re-pierced by the lead wire 25, butt their conical tips and provide additional insulation by wrapping an insulating tape around them. It is rejoined by 28. An insulating barrier 29 is then applied surrounding the joint.

FIG. 3 is a structural diagram of a joint portion of another conventional lead wire insulating tube, in which the same reference numerals indicate those that are the same as those described above or have the same functions. The tip of one insulating tube 31 that surrounds and insulates the lead wire 25 is connected to the other insulating tube 26.
It is formed to have a concave cross section so that it fits into the conical tip of the tube. An additional insulation 32 made of thin insulating paper is wrapped around the joint outer diameter portion of both the insulating tubes 26, 31.
The gap 32 that occurs in the conical joint due to the misalignment of the centers of the conical joints is reinforced, and an insulating barrier similar to the insulating barrier 29 shown in FIG. 2 is placed outside of the gap 32 as required.

As described above, in the conventional structure, it is necessary to perform additional insulation 28, 32 and installation of an insulation barrier during reassembly at the installation site. Because the insulators near the connections are exposed to the atmosphere for long periods of time during these operations, moisture absorption is unavoidable. Since vacuuming time is required, there is a drawback that more man-hours are required for reassembling.

[Purpose of invention]

The purpose of this invention is to eliminate the need for additional insulation during rejoining without impairing the insulation performance of the joint and its vicinity.

[Key points of the idea]

This objective is achieved by the following configuration. That is, the joint part of the insulating tube that surrounds and insulates the lead wire of the electric appliance and can be separated from each other in the axial direction is a fitting having a cylindrical surface parallel to the axis of the insulating tube and a conical surface that expands following this cylindrical surface. An insulating barrier is provided with a mating part, and is arranged outside the insulating tube surrounding the mating part, and is fixed to each of the insulating tubes separated from each other so as to be separable together with the insulating tube, Additional insulation is provided at the joint by providing insulating barriers in which the tips of the insulating barriers overlap each other and the overlapping length is shorter than the axial length of the cylindrical surface in the fitting part. It is possible to eliminate the need to apply it. Since the overlapping length of each insulating barrier is smaller than the axial length of each cylindrical surface, in an incompletely inserted state where both cylindrical surfaces are slightly opposed in the radial direction, the tip of the insulating barrier do not overlap, and from this it can be seen that the opposing surfaces of both conical surfaces of the insulating tube are separated by a distance greater than that required for insulation. Because the fitting part has a cylindrical surface, uneven distribution of the gap formed by the conical surfaces is suppressed, and by overlapping the tips of the insulation barrier, the insulation barrier can be inserted until the gap becomes less than the allowable dimension for insulation. is guaranteed.

Since the radial length of the insulating tube in the gap created at the joint is guaranteed by this configuration, the positional relationship between the radial thickness of the insulating tube and the insulating barrier and the insulating medium such as insulating oil surrounding them is Can be easily designed. Furthermore, the creepage length on the insulation including the joint surface can be easily designed by taking into account the outer surface of the insulation tube and the insulation barrier. With such a configuration, joints that are separated and reassembled do not require additional insulation.

[Example of idea]

FIG. 1 shows an embodiment of this invention, in which the lead wire 2
5 are insulating tubes 2 that can be separated from each other at the joint 1;
The surrounding area is insulated by and 3. At the tip of one insulating tube 2, a cylindrical portion 2a having a diameter d and a truncated conical portion 2b having a conical surface expanding from the diameter d are formed. The other insulation tube 3
has a recess formed at the tip thereof into which the cylindrical portion 2a and the truncated conical portion 2b of the insulating tube 2 can be fitted, and the cylindrical surface 2c, 3c and the conical surface 2d, 3d respectively.
constitutes a fitting portion 4. Insulation tubes 2, 3
are provided with insulating barriers 5, 6 which are fixed to each other, and which surround the mating part 4. The respective insulating barriers 5 and 6 are formed concentrically with the insulating tube and have different diameters, and are so formed that they can be inserted so that their open end tips 5a and 6a overlap. The overlapping length of the open ends of this insulating barrier is the length of the cylindrical surface 2 provided on the insulating tubes 2 and 3.
c and 3c, and during the insertion process in which at least a portion of each of the two cylindrical surfaces does not oppose in the radial direction of the insulating tube, the open ends 5a and 6a of the insulating barrier are made so that they do not overlap. When the insertion process progresses to the point where the open ends 5b and 6a overlap, the conical surfaces 2d and 3d of the respective insulating tubes are set to approach each other with a predetermined gap or less. The deviation of the radial ring-shaped gap formed by the conical surfaces is suppressed by the length of the axial fit between the cylindrical surfaces. Since this gap is guaranteed to be less than or equal to a predetermined dimension, the penetration dielectric strength at the fitting part 4 between the lead wire 25 and another potential part (not shown) is equal to that of the insulating tube and the insulating barrier surrounding it. , and an insulating medium such as insulating oil existing between them. Although only a pair of insulating barriers are shown in FIG. 1, any suitable barrier may be provided so as not to impede monitoring of said overlap, and is particularly useful in increasing creepage strength. The insulating tube 2 is the outgoing side of the lead wire that is separated and sent separately due to transportation restrictions, and its tip may be damaged. This tip is located inside the open end surface of the insulating barrier 5. It is advantageous that the tip of the cylindrical portion 2a and the bottom of the axially opposing recess of the insulating tube 3 form an inclined surface so that the gap between these opposing surfaces becomes smaller in the radial direction. According to such a configuration, although there is essentially a gap between the fitting portions 4 of both insulating tubes, the size of the gap can be extremely easily maintained within controlled dimensions. It is very easy to accurately monitor the overlapping dimension of the tips 5a and 6a of the insulating barrier, so that the mating part is not damaged by transient insertion. The insulating tubes 2, 3 are supported by lead supports 7, 8, respectively, via an insulating barrier.

[Effect of idea]

With the configuration of the present invention, the joints of the insulating tubes do not require any insulation processing, so reassembly work can be carried out in a short time, and moisture absorption of surrounding insulators can be minimized. During reassembly, the insulation at the insulating tube joints is easily placed into position, so that insulation performance is maintained and guaranteed.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the lead wire insulated tube joint according to the embodiment of this invention, Fig. 2 is a diagram showing the relationship between the conventional lead wire insulated pipe joint and the electrical appliance, and Fig. 3 is another conventional joint. FIG. 1: Joint part, 2, 3: Insulating tube, 2a: Cylindrical part,
2b: truncated conical part, 2c, 3c: cylindrical surface, 2d, 3
d: Conical surface, 4: Fitting portion, 5, 6: Insulating barrier, 5a, 6a: Tip of insulating barrier, 25: Lead wire.

Claims (1)

[Scope of utility model registration request] A fitting part in which the joint part of an insulating tube that surrounds and insulates the lead wire of an electric appliance and can be separated from each other in the axial direction has a cylindrical surface parallel to the axis of the insulating tube and a conical surface that expands following this cylindrical surface. and an insulating barrier which surrounds this fitting part and is arranged on the outside of the insulating tube and is fixed to each of the insulating tubes and separated from each other so as to be separable together with the insulating tube. Joining of lead wire insulating tubes, characterized in that the insulating barriers are formed such that the tip portions of the insulating barriers overlap each other, and the overlapping length is shorter than the axial length of the cylindrical surface in the fitting portion. Departmental structure.