JPH0711452Y2 - Transformer with tap terminal - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to a transformer with a tap terminal provided with a tap terminal for adjusting a transformer ratio.

(Prior Art) Conventionally, as an example of a transformer with a tap terminal having a relatively small capacity, a tap lead wire pulled out from the middle of winding of a coil is connected to a terminal block provided on a side portion of a transformer body. There is a configuration in which a plurality of tap terminals are arranged. Further, when it is necessary to secure the ground insulation of each tap terminal, an insulating cover is attached so as to cover the terminal block in an airtight manner.

(Problems to be Solved by the Invention) In the above-described conventional transformer with tap terminal, the insulation distance between tap terminals on the terminal block needs to be relatively large because the insulation is performed in the air. Therefore, there is a problem in that the terminal block portion and eventually the entire size are increased.
Further, due to the formation of the airtight space inside the insulating cover, dew condensation may occur inside the insulating cover, and in such a case, rust may occur on the terminals or a short circuit between the terminals may occur.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the size of a terminal block for a tap terminal and to prevent the terminal from rusting and short circuit between terminals while insulating the ground from the terminal. (EN) It is possible to provide a transformer with a tap terminal, which has an effect of improving the above.

[Structure of the Invention] (Means for Solving the Problems) A transformer with a tap terminal according to the present invention is provided with an insulating cover covering a plurality of tap terminals on a terminal block, and between the insulating cover and the terminal block. The space formed in the above is filled with a gel insulator.

(Function) When the space between the insulating cover and the terminal block is filled with the gel insulator, the space between the tap terminals is filled with the gel insulator. The dielectric strength between the space, the tap terminal and the ground is improved. As a result, the distance between the terminals can be reduced, and the terminal block can be downsized. Moreover, as a result of the gel-like insulator being filled in the space between the insulating cover and the terminal block, there is no risk of dew condensation on the terminal block part. As a result, there is no risk of rusting of the tap terminals or a short circuit between the terminals.

(Embodiment) FIG. 1 shows a longitudinal sectional structure, and FIG. 2 shows an appearance of a coil portion.

In FIGS. 1 and 2, a low voltage coil 2 is wound around a rectangular insulating cylinder 1, and a high voltage coil 4 is wound around the low voltage coil 2 via a duct rail 3. . Insulation layers made of glass tape, glass cloth, polyamide non-woven fabric, polyamide glass mixed non-woven fabric, etc. between the windings of each coil 2 and 4 and the inner and outer peripheral surfaces of each coil 2 and 4 (the outermost one in Fig. 2). (Only indicated by reference numeral 5) is provided, and a curing accelerator for an epoxy resin, which will be described later, is previously attached to this insulating layer.

In the low voltage coil 2, the lead wire 6 is drawn out from the upper end surface side thereof. In the high-voltage coil 4, lead wires (not shown) drawn from both ends of the high-voltage coil 4 are connected to output terminals 7 and 8 provided so as to be exposed at upper and lower portions of the outermost insulating layer 5. . Further, a plurality of tap lead wires 9 drawn out from predetermined positions in the middle of winding of the high voltage coil 4 are extended to the outside of the outermost insulating layer 5.

A rectangular terminal box 10 is attached to the outside of the insulating layer 5 so as to be located between the output terminals 7 and 8.
The terminal box 10 is entirely made of an insulating material, and supports the terminal block 12 in a rectangular frame 11.
The opening of the frame 11 is closed by an insulating cover 13. In this case, leg portions 11a having a shape along the insulating layer 5 are integrally formed above and below the frame body 11, and each leg portion 11a is made of a high-strength fiber material wound around the insulating layer 5. The frame body 11 is fixed by being pressed by the fixing tape 14. Also, on the upper side of the frame 11, an insulating cover
Injection port communicating with the space formed between 13 and terminal block 12.
11b is formed.

A plurality of tap terminals 15 are provided on the terminal block 12 in a penetrating manner, and the tap lead wires 9 are connected to the base ends of these terminals 15. In this case, each lead wire 9 is wound and insulated by an insulating tape together with a connection portion for each tap terminal 15.

Then, the coil assembly 16 configured as described above is housed in a resin impregnation container (not shown), and in this state, for example, epoxy resin is impregnated under vacuum pressure. In this case, since the curing accelerator is applied between the windings of the coils 2 and 4 and the insulating layer on the inner and outer peripheral surfaces of the coils 2 and 4, the epoxy resin is semi-cured early in the applied part. A state is reached, and at this point, it is taken out from the impregnation container. Then, the epoxy resin impregnated inside the coil assembly 16 is further cured to form a resin mold layer 17
Is formed.

After that, the coil assembly 16 is assembled into the iron core 18 to form a transformer, and at the time of installation, with the insulating cover 13 removed, the terminal block so that the temporary side and the secondary side have a desired transformer ratio. Twelve predetermined tap terminals 15 are connected to each other by connecting fittings 19.

Then, after this, with the insulating cover 13 attached at a predetermined position, silicone gel is injected from the injection port 11b into the space formed between the insulating cover 13 and the terminal block 12 to cure it. The space is filled with the gel insulator 20.

By the way, the silicone gel shows the properties of a low-viscosity fluid before curing and the soft agar-like properties after curing, and exhibits excellent electrical characteristics in a wide range of temperature and frequency regions. It can be used as an insulating material, and has various properties such as excellent sealing property, moisture resistance, water repellency, and excellent adhesiveness, adhesiveness, heat resistance and cold resistance.

Therefore, when the gel insulator 20 made of silicone gel is filled in the space formed between the insulating cover 13 and the terminal block 12 and cured as in this embodiment, the silicone gel before curing is Due to the fluidity shown, the gel insulating material 20 is filled into the details of the space. As a result, the space between the tap terminals 15 is filled with the gel insulator 20, and the dielectric strength between the terminals 15 and between the terminals 15 and the ground is improved. This allows each tap terminal
It is possible to reduce the distance between 15 and 12 terminal blocks.
As a result, the size of the terminal box 10 can be reduced.

Further, as a result of filling the space between the insulating cover 13 and the terminal block 12 with the gel insulator 20, there is no risk of dew condensation on the terminal block 12 portion, and moreover, the external or coil assembly 16 is formed on the terminal block 12 portion. Even if moisture penetrates from the side, gel insulator 20
Due to the sealing property, the moisture resistance, the water repellency, the adhesiveness, etc., the invading moisture becomes difficult to reach the tap terminal 15. As a result, there is no risk that rust will occur in the tap terminal 15 or a short circuit between terminals will occur.

After the installation of the transformer, the transformation ratio is rarely switched by the tap terminal 15, but the switching can be easily performed while deforming the gel insulator 20 having agar-like properties.

Further, in the above embodiment, the back side of the terminal block 12 may be formed in a frame shape and the inside thereof may be filled with silicone gel.

[Effects of the Invention] As described above, the present invention provides an insulating cover that covers a plurality of tap terminals on a terminal block, and a gel insulation in a space formed between the insulating cover and the terminal block. It is characterized in that it is filled with an object, that is, a structure in which the space between each tap terminal is filled with a gel-like insulator. As a result of this configuration, the insulation distance between each of these tap terminals can be reduced, and the terminal block can be miniaturized.
It is possible to improve the dielectric strength of the tap terminal to ground. Moreover, as a result of the space between the insulating cover and the terminal block being filled with the gel-like insulator, there is no risk of dew condensation on the terminal block part, which may cause rust on the tap terminal or short circuit between terminals. There is no fear.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a vertical sectional view of a right half portion, and FIG. 2 is a perspective view of a main portion. In the figure, 2 is a low voltage coil, 4 is a high voltage coil, 10 is a terminal box, 11 is a frame, 12 is a terminal block, 13 is an insulating cover, 15 is a tap terminal, 17 is a resin mold, and 20 is a gel insulator. Show.

Claims (1)

[Scope of utility model registration request] 1. A transformer with a tap terminal, comprising: a plurality of tap terminals provided on a terminal block; and a plurality of tap lead wires drawn from the middle of winding of a coil connected to the tap terminals. A transformer with a tap terminal, characterized in that an insulating cover covering the tap terminal is provided, and a space between the insulating cover and the terminal block is filled with a gel insulator.