JPH0331067Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a bushing current transformer that is fitted into a bushing of a transformer or the like and uses the bushing as a primary conductor.

[Technical background of the invention and its problems]

Since bushing current transformers are installed in the transformer's insulating oil, it is common to take advantage of this favorable condition and adopt an oil-immersed insulation structure, instead of using expensive resin mold insulation. 5 to 7 show this type of bushing current transformer, 1 is the main body, which consists of an annular core 2 and an oil-impregnated material such as so-called crepe tape made by secondary processing kraft paper and adding horizontal wrinkles. an inner insulation 3 made of a good insulator; a secondary winding 4 wrapped around the outer periphery of the inner insulation 3; and an outer periphery made of crepe tape or the like wrapped around the outer periphery of the secondary winding 4. and an insulator 5 (see Fig. 6). A lead wire 6 of the secondary winding 4 is provided on the outer peripheral side of the main body 1.
These lead wires 6 are made of stranded annealed copper wire with high mechanical strength covered with a polytetrafluoroethylene resin tube or the like, and are connected to both ends of the secondary winding 4, respectively. In this case, as shown in FIG. 7, the lead wire 6 is tied and fixed to the side surface of the main body 1 with thread 7 such as cotton thread before applying the outer insulation 5, and in this state, the outer insulation 5 is applied. administered.

However, in such a conventional configuration, the binding portion for fixing the lead wire 6 to the main body 1 is small;
Furthermore, due to restrictions on the size and shape of the lead wire 6, the binding material is limited to small cross-sectional areas such as threads, so it is difficult to firmly fix the lead wire 6, and requires considerable skill. Such fixing has the disadvantage that it is weak against mechanical external forces caused by connection work during installation of the main body 1 or vibrations after installation. In addition, as a fixing structure for this type of lead wire, for example,
There is one described in Publication No. 93118. In this device, the lead wires of the zero-phase current transformer are temporarily fixed in a holder with one open U-shaped notch for each lead wire, and are further fixed with thermosetting resin. In the above-mentioned holder, the cut portion only has a temporary fixing function, and it is impossible to fix the lead wire without using a thermosetting resin. Therefore, it is impossible to fix the lead wire with the holder for those that do not use thermosetting resin.

[Purpose of invention]

This idea was made in view of the above points,
The purpose is to easily fix the lead wire, and
It is an object of the present invention to provide a bushing current transformer capable of improving the fixing strength of its lead wire.

[Summary of the idea]

The present invention has a pair of through holes for each lead wire at a predetermined pitch, and the lead wire is passed through one of the through holes from the front side and the other through hole from the back side. It is characterized by the provision of a fixing plate and a fixing means for fixing the fixing plate to the current transformer main body, thereby making it possible to use a fixing plate with a relatively large area for the lead wire. It can be easily fixed to the current transformer body through the cable.

[Example of idea]

The first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. The appearance and partial cross-section of the current transformer body in the completed state are shown in FIGS.
Since it is similar to the figure, these will be omitted and only the different parts will be explained. That is, FIG. 1 shows a bushing current transformer before outer insulation is applied, and 8 is a rectangular fixing plate made of, for example, a press boat, which is physically and chemically stable against insulating oil, and has a predetermined shape. Pitzchi
A pair of through holes 9a and 9b with
The inner diameters of a and 9b are slightly larger than the outer diameter of the lead wire 6. Now, in order to pass the lead wire 6 through the fixed plate 8, as shown in FIG.
is first passed through the lower through hole 9b from the front side of the fixing plate 8, and then passed through the upper through hole 9a from the back side.In this way, the lead wire 6 is passed through the fixing plate 8. Attach. In this state, use a fixing means such as cotton tape (not shown).
The fixing plate 8 is tightly fixed to the main body 1, and the outer circumferential insulation 5 (see FIG. 5) is further applied thereon.

According to this embodiment, the following effects can be obtained. That is, the lead wire 6 is attached by passing through the pair of through holes 9a and 9b of the fixing plate 8, and in this state, the fixing plate 8 is tightly fixed to the main body 1 with tape, so that the tied part becomes larger, and the strength of fixation can be increased. Moreover, since the fixing plate 8 is a rectangular flat plate that can be formed into a relatively large area, the fixing plate 8 can be easily secured to the main body 1.

FIGS. 3 and 4 show a second embodiment of the present invention, and only the differences from the first embodiment will be described below.

That is, 10 is a fixing plate replacing the fixing plate 8, which has a pair of through holes 11a and 11a shown by broken lines in FIG.
It is configured to be bendable at the intermediate line A portion of 11b. To attach the lead wire 6 to this fixed plate 10,
First, the fixing plate 10 is bent into a mountain-fold shape at the intermediate line A, and the lead wire 6 is passed through the through holes 11a and 11b (see a in FIG. 4). Then, fix the lead wire 6 to the fixing plate 1.
After penetrating the fixing plate 10 to a predetermined position, the bent portion of the fixing plate 10 is opened to its original position (see b in FIG. 4). Furthermore, the upper and lower ends of the fixed plate 10 are connected to the lead wire 6.
The curved part is tied and fixed to the main body 1 with a tape (not shown) (fourth
(See figure c).

Therefore, in the second embodiment, the same effects as in the first embodiment can be obtained, but in particular, the lead line 6
In cases where the wire requires a large cross-sectional area due to the current rating or the length of the lead wire, and bending with a small curvature is difficult due to the increased diameter, the lead wire 6 itself can be bent by bending the fixed plate 10. Since it is not necessary to do so, the lead wire 6 can be easily attached to the fixed plate 10.

In each of the embodiments described above, it goes without saying that the width dimensions of the fixing plates 8 and 10 can be set as appropriate depending on the number of lead lines 6.

[Effect of idea]

As is clear from the above description, the present invention has a pair of through holes for each lead wire at a predetermined pitch, and the lead wire penetrates one of the through holes from the front side, and the other through hole. A fixing plate that penetrates the hole from the back side and a fixing means for fixing this fixing plate to the current transformer body are provided, making it possible to easily and firmly fix the lead wire to the current transformer body. be effective.

[Brief explanation of the drawing]

1 and 2 show a first embodiment of the present invention, in which FIG. 1 is a perspective view with the outer insulation removed, FIG. 2 is a plan view of the fixing plate, and FIG. 3 and 4 show a second embodiment of the present invention, FIG. 3 is a view corresponding to FIG. 2, and FIG. 4 is a side view showing the procedure for attaching the fixing plate. Furthermore, FIGS. 5 to 7 show the conventional configuration, with FIG. 5 being a perspective view of the entire completed state, and FIG.
FIG. 7 is a diagram corresponding to FIG. 1. In the drawing, 1 is the current transformer main body, 2 is the annular core, 4 is the secondary winding, 5 is the outer periphery insulation, 6 is the lead wire, 8, 10
indicates a fixed plate, and 9a, 9b, 11a, and 11b indicate through holes.

Claims (1)

[Claims for Utility Model Registration] (1) A current transformer body having an annular core around which a secondary winding is wound is fitted around a bushing so that the bushing becomes a primary conductor. , in which a lead wire coated with insulation is led out from the secondary winding, each lead wire has a pair of through holes at a predetermined pitch, and the lead wire is connected to one of the through holes. A bushing current transformer characterized in that it is provided with a fixing plate that is penetrated from the front side of the through hole and from the back side of the other through hole, and a fixing means that fixes the fixing plate to the current transformer main body. . (2) The bushing current transformer according to claim 1, wherein the fixing plate is configured to be bendable at the midline between the pair of through holes.