JPS6020908Y2 - molded transformer - Google Patents

Description

[Detailed Description of the Invention] The present invention particularly relates to a molded transformer with an improved cross-contact prevention support structure.

Figure 1 shows a low voltage coil 1 attached to the iron core leg 4 of a molded transformer.
and shows a state in which the high voltage coil 2 is installed.

In the conventional example shown in FIG. 1, a metal contact prevention plate (electrostatic shielding plate) 5 as shown in FIG. 2 is wrapped around the outer circumference of the low voltage coil 1 in order to electrostatically shield the low voltage circuit. It is fixed with insulating tape 6.

15 is a lead wire that grounds the contact prevention plate 5.

In such a conventional structure, it is necessary to separately attach the cross-contact prevention plate 5 to the down-shaped coil 1 cast with resin 3, and when fixing with insulating tape 6, etc., the adhesive may be incomplete. It is conceivable that problems such as the cross-contact prevention plate 5 falling off or poor contact with the outer periphery of the low-voltage coil 1 may occur, creating an air layer and causing partial discharge.

The purpose of this invention is to make the installation work of the cross-contact prevention plate simple and easy.
The object of the present invention is to provide a molded transformer that does not fall after installation and can prevent the generation of gaps in the installation part.

The molded transformer of the present invention has a high-voltage coil and a low-voltage coil wound on iron core legs, and a cross-contact prevention plate placed between both coils to shield the low-voltage circuit from the high-voltage coil. An inorganic reinforcing insulating material is wound around the outside of the insulating layer formed on the outer periphery, and a contact prevention plate is formed between the reinforcing insulating material outer periphery and a semi-hardened glass fiber layer impregnated with a thermosetting resin disposed around the outer periphery of the reinforcing insulating material. The glass fiber layer is integrated and fixed by an outer peripheral insulator formed by heating and hardening the glass fiber layer.

An embodiment of the molded transformer of the present invention will be described below with reference to FIGS. 3 and 4, with the same parts as those of the prior art indicated by the same reference numerals.

The low-voltage coil 1 is formed by alternately winding a conductor 12 and an interlayer insulating paper 11 around an inner insulating tube 8 as a winding core, and an insulating layer 13 is provided on the outer periphery.

A reinforcing insulator 14 made of an inorganic material such as mica is wound between the insulating layer 13 and the contact prevention plate 5 wound around the outer periphery, and has an insulating thickness necessary for the applied voltage. A contact prevention plate 5 is wound around the outer periphery, and an insulating cylinder 9 pre-impregnated with a thermosetting epoxy resin and semi-cured is further wound around the outer periphery of the glass fiber forming phase.

As shown in FIG. 4, the contact prevention plate 5 is provided with a plurality of small holes 7 over its entire surface so that drying of the insulator and impregnation with the resin can be carried out smoothly.

When the low voltage coil 1 is heated, the thermosetting epoxy resin impregnated into the glass fiber cloth melts and hardens, and the contact prevention plate 5
The insulating cylinder 9 is formed by fixing the glass fibers together with the glass fibers and integrating them.

When the glass fiber layer is heated, the thermosetting epoxy resin melts, enters the small holes 7, becomes entangled, and hardens. Since they are completely fixed together, there is no risk of them peeling off.

Incidentally, the inner peripheral insulating cylinder 8 may also be formed by a similar method.

In this way, the low voltage coil 1 has a contact prevention plate 5 on its outer periphery.
Then, the entire winding is molded by injecting thermosetting resin 10 into the space between the inner and outer insulating cylinders 8 at both ends and the insulating layer 13 at the outer periphery.

In this way, in the molded transformer of this example, the metal cross-contact prevention plate is wrapped in glass fiber and hardened integrally with the low-voltage coil, so the metal cross-contact prevention plate is directly attached to the resin near the winding. There is no possibility of cracks occurring as would be the case if it was fixed by solid wood.

In particular, when the glass fiber layer is heated, the thermosetting epoxy melted through the small holes integrates the contact prevention plate, the reinforcing insulating layer, and the outer insulating cylinder, so there is no risk of peeling between them.

Further, since the contact prevention plate is attached to the winding wire during the winding work, the work of attaching it to the molded low-voltage coil later can be omitted, making the work simple and easy.

Since the cross-contact prevention plate is closely attached and fixed to the outer periphery of the windings using glass fiber and epoxy resin, there is no fear of it falling off like in the past. Since it has a solid insulation structure with almost no insulation, long-term insulation stability can be expected.

As described above, the molded transformer of the present invention has the following effects: the cross-contact prevention plate can be easily installed, does not fall off after installation, and can prevent air gaps from forming at the installation part. .

[Brief explanation of the drawing]

Figure 1 is a longitudinal cross-sectional view of a part of a conventional molded transformer;
The figure is a perspective view of the cross-contact prevention plate of the transformer shown in Fig. 1, FIG. 3 is a longitudinal sectional view of a low-voltage coil of an embodiment of the molded transformer of the present invention, and FIG. 4 is a cross-sectional view of the cross-contact prevention plate of the transformer shown in FIG. FIG. 1...Low voltage coil, 2...High voltage coil, 4...Iron core leg, 5...Touch prevention plate,
9... Insulating tube, 13... Insulating layer, 14
...Reinforced insulation.

Claims (1)

[Scope of utility model registration request] High voltage coil 2 and low voltage coil 1 wound on iron core leg 4
and a cross-contact prevention plate 5 disposed between both coils to shield the low voltage circuit from the high voltage coil, in which an inorganic reinforcing insulator is wound around the outside of the insulating layer 13 formed around the outer periphery of the low voltage coil. A cross-contact prevention plate provided with a material 14 and having a plurality of small holes is installed between the outer periphery of the reinforcing insulator and a semi-cured glass fiber layer impregnated with a thermosetting resin disposed outside the reinforcing insulator, and A molded transformer characterized in that a fiber layer is integrated with an outer peripheral insulating cylinder formed by heating and hardening.