JPH0419773Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement in the high-voltage side lead wire of the primary coil of an instrument transformer.

Conventionally, in instrument transformers used in relatively high-voltage circuits, the high-voltage side lead wire of the primary coil has been integrated with the high-voltage shield of the primary coil.

FIG. 1 shows an example of the structure of a conventional voltage transformer of this kind, in which a secondary (low voltage) coil 3 and a primary (high voltage) coil 4 wound around an iron core 2 are housed in a lower container 1. . The winding start end of the primary coil 4 is drawn out to the outside of the container 1 by a low-voltage lead wire 5 and grounded, and the winding end is connected to a high-voltage shield 6 provided around the outer periphery of the primary coil, and is connected to an insulator tube 8 through a lead rod 7. It is connected to an upper container 10 and a primary terminal 11 by a lead wire 9 from its upper end.

Here, the lower end of the lead rod 7 is integrally formed with the high voltage shield 6 by welding or screwing, and an insulating layer 12 is provided together with the high voltage shield 6.
Note that the lead rod 7 is held by a steady rest 13 whose upper end is attached to the upper container 10 so as to prevent it from vibrating.

As described above, since the lead rod 7 has an integral structure with the high voltage shield 6, it is difficult to apply the insulating layer 12 on the outer periphery, and the workability during assembly is very poor. In order to arrange the lead rod 7 correctly at the center position, it is necessary to connect the high voltage shield 6 and the lead rod 7 and to assemble the inside thereof with extremely high precision. This inevitably requires a lot of labor and time, and increases the price.

The present invention solves the above-mentioned drawbacks and facilitates insulation processing and assembly, and embodiments thereof will be described in detail below.

In FIG. 2, 14 is a high-voltage shield provided around the outer periphery of the primary coil 4 as in the conventional case, and the difference from the conventional one is that a lead rod is not used, but instead a lead pipe 16 is connected to the upper container 10 by a hanging fitting 15. is suspended, and its lower end is inserted into a small hole provided in the high voltage shield 14.

A lead wire 17 is inserted into the lead pipe 16, and the lower end of the lead wire 17 is connected to the high voltage shield 14.
The upper end is connected to the upper end of the lead pipe 16 and the upper container 10, and is further connected to the primary terminal 11 by the lead wire 9. Note that the high voltage shield 14 and the lead pipe 16 are provided with an insulating layer 12 that is similar to the conventional case, but as shown in the figure, an insulating layer surrounding the high voltage shield 14 and an insulating layer surrounding the lead pipe 16 are separate. ing.

In this way, in the present invention, the high voltage shield 1
A lead wire 17 is used for connection between 4 and the upper container 10.
The lead wire 17 is not simply left in the insulator tube 8, but is housed in the lead pipe 16, and the high voltage shield 14 and the lead pipe 16 are insulated separately. Note that the lead pipe 16 is inserted into the high voltage shield 14 with its lower end insulated, and its upper end is connected to a lead wire 17 and kept at the same potential.

Therefore, when assembling, the high pressure shield 14 should be placed correctly and the hanging fitting 15 should be attached to the upper container 10.
is installed accurately, the lead pipe 16 is suspended through the center of the insulator pipe 8, and the lower end is connected to the high pressure shield 1.
4 so that it is held.

In this way, unlike the conventional case where the lead wire and the high voltage shield are integrated and the insulating layer 12 is applied in common, the high voltage shield can be formed without spending much effort on insulating the outer periphery and assembling. 14 and lead pipe 16 are separately insulated,
At the final stage of assembly, the lower end of the lead pipe 16 suspended from the upper container 10 by the hanging fitting 15 is inserted into the high pressure shield 14.

In this way, the lead pipe can be easily placed in the center of the porcelain tube, and the high voltage shield and the insulation layers of the lead pipe can be easily applied. The portion of the lead pipe 16 inserted into the high-voltage shield 14 is shaped so that there is no risk of electric field concentration, and is held in a predetermined position via an insulating layer.

As explained above, according to the present invention, 1
The connection between the end of the next coil winding and the primary terminal is made by a lead wire housed in a lead pipe, and the lead pipe is insulated separately from the high voltage shield, and its tip is inserted and held in the high voltage shield. It is connected to the above lead wire so that it is kept at the same potential, and since the lead pipe and high voltage shield are formed separately from each other, high precision is not required during assembly, and assembly and insulation processing can be easily performed. be able to.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a conventional potential transformer, and FIG. 2 is a sectional view showing an embodiment of the present invention. 1...Lower container, 4...Primary coil, 8...Insulator tube, 10...Upper container, 11...Primary terminal, 12
...Insulating layer, 14...High voltage shield, 16...Lead pipe, 17...Lead wire.

Claims (1)

[Scope of utility model registration request] a high voltage shield provided around the outer periphery of the primary coil in the lower container and connected to the winding end of the primary coil; an insulating layer applied to the outer periphery of the high voltage shield; A lead wire is connected to a primary terminal attached to an upper container provided through an insulator tube, and a lead wire is housed and suspended from the upper container through the insulator tube into the lower container, and the lower end is inside the high pressure shield. The lead pipe includes an inserted lead pipe and an insulating layer applied to the outer periphery of the lead pipe, the lead pipe is connected to the lead wire and kept at the same potential, and the insulating layer applied to the outer periphery of the high voltage shield and the lead are connected. An instrument transformer characterized in that the insulating layer provided on the outer periphery of the pipe is constructed separately from each other.