JPH03212915A - Formation of resin mold transformer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a resin mold for manufacturing a resin mold transformer by molding the transformer main body housed and fixed in a mold with resin. This invention relates to a method for manufacturing a transformer.

(Prior Art) A wide variety of resin mold transformers are manufactured and used. Figure 4 shows the state of a resin mold grounded voltage transformer A, which is one of the resin mold transformers, during manufacture. This will be explained with reference to the figures.

First, FIGS. 5 and 6 show a state in which the transformer main body 1 is housed and fixed in the mold 2. As shown in FIGS.

The transformer main body 1 is composed of a split iron core 3 having an overall rectangular ring shape, and a cylindrical coil 4 formed by winding a primary coil around a secondary coil. The split core 3 includes a core main body 5 having a substantially U-shape having a pair of legs 5g and 5b, and a substantially C-shape core disposed so as to abut the end faces of both legs 5a and 5b. The auxiliary part 6 is combined with the auxiliary part 6, and the belt 7 is used to tighten the belt 7. The coil 4 is attached to one leg 5a of the core main body 5 before the core main body 5 and the core auxiliary part 6 are combined.
It is wound around the fixing piece 8 via the fixing piece 8.

On the other hand, the mold 2 is configured in a box shape by a bottom plate 2a, an N side plate 3b, and a top plate 2C.

Before the mold 2 is assembled, the transformer body 1 is placed on the bottom plate 2a of the mold 2 with the other leg 5b of the core main body 5 facing down, with an insulating plate 9 interposed therebetween. . The clamp 10 for fixing the transformer main body 1 is
As shown in Fig. 7, a U-shaped metal holding plate 1
Metal fixing fitting 1 having screw holes 12a on both sides of 1
2 are welded together, and the holding plate 11 is placed on the other leg 5b so as to straddle this, and the screw 13 is attached to the bottom plate 2.
The transformer main body 1 is fixed to the bottom plate 2a by screwing into the screw hole 12a of the fixing fitting 12 through the insulating plate 9 and the insulating plate 9.

Next, the side plate 2b of the mold 2 is assembled so as to surround the transformer body 1, and the primary ground terminal 14 and the secondary terminal 15 are attached to the lower part of the inner surface of the side plate 2b, and then the upper plate 2C is assembled. At the same time, a high voltage terminal 16 is attached to the lower surface of the upper plate 2C.

With the transformer main body 1 housed and fixed in the mold 2 in this way, resin is injected from the resin injection port 17 formed in the upper plate 2C, and after the resin is primarily cured, the bottom plate 2a and the side plates of the mold 2 are injected. By removing the upper plate 2b and the upper plate 2C and performing secondary curing, a molded article in which the transformer body 1 is molded with the resin 18 as shown in FIG. 4 is manufactured.

Then, by attaching the base 19 to the bottom of this molded product, the voltage transformer A having a resin molded grounding surface is completed.

(Problem to be solved by the invention) The above manufacturing method has the following drawbacks.

(1) Since the transformer body 1 is fixed via the U-shaped clamp 10, the attachment strength of the transformer body 1 to the mold 2 is insufficient, and the attachment tends to be unstable. Therefore, if the mold 2 is tilted with the transformer body 1 fixed, there is a risk that the transformer body 1 will be displaced, and therefore the mold 2 cannot be tilted when pouring resin or the like.

Therefore, since the resin needs to be injected with the transformer main body 1 vertical, the injection direction is limited.

(2) Furthermore, the width of the presser plate 11 in the U-shaped clamp 10 needs to match the leg 5b, but if the width is smaller than the leg 5b, it may not be possible to attach it. be.

Further, if the width dimension is large, the leg portion 5b cannot be fixed due to insufficient tightening.
It is necessary to insert padding between the presser plate 11 and the presser plate 11 for adjustment, resulting in poor assembly workability.

(3) Since the holding plate 11 of the clamp 10 exists between the other leg 5b of the core main body 5 and the coil 4, the dimensions for ensuring insulation between the other leg 5b and the coil 4 are determined. It is necessary to increase the thickness of the holding plate 11. For this reason, the transformer main body 1 and the entire transformer become larger in size.

(4) Furthermore, since the clamp 10 is arranged so as to straddle the leg portion 5b, when the lower end of the fixture 12 of the clamp 10 directly contacts the base 19, the clamp 10 and the base 19 move around the leg portion 5b. There is a risk that a one-turn circuit will be formed and a large current will flow through this circuit, and in order to prevent this, it is necessary to interpose the insulating plate 9 between the fixture 12 and the bottom plate 2a.

The present invention has been made in view of the above circumstances, and its object is to provide a resin molded transformer that can securely and easily fix the transformer body to a mold, has fewer component parts, and can also be made smaller. To provide a manufacturing method.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a core main body portion having a substantially U-shape having a pair of legs, and a core auxiliary portion disposed so as to come into contact with the end surfaces of the legs. The transformer body is comprised of a split core constructed by combining the two cores, and a coil wound around one leg of the core main body. In the method of manufacturing a resin molded transformer by injecting resin into a mold, a screw hole is formed in the other leg of the main body of the core, and the transformer main body is housed in the mold. The present invention is characterized in that it is fixed to the mold by screwing a screw into the screw hole through the mold in the state of the mold.

(Function) Since the transformer main body is directly fixed to the mold with screws, the transformer main body can be reliably fixed to the mold and the fixing work can be easily performed.

Furthermore, since the transformer body can be securely fixed to the mold, the transformer body will not be displaced even if the mold is tilted during resin injection, and the degree of freedom in the resin injection direction is increased. Furthermore, since the space between the other leg of the core main body and the coil is entirely molded with resin, there is no need to increase the dimensions for insulation between them, and special parts such as clamps are not required. I don't.

(Example) Hereinafter, an example in which the present invention is applied to a method of manufacturing a voltage transformer having a resin molded grounding surface will be described with reference to FIGS. 1 to 4. However, the same parts as in the prior art will be described with the same reference numerals.

First, Figures 1 and 2 show the transformer body 1, which is the transformer body.
The figure shows a state in which it is housed and fixed in the mold 2. The transformer main body 1 is composed of a split iron core 3 having an overall rectangular ring shape, and a cylindrical coil 4 formed by winding a primary coil around a secondary coil. Split type iron core 3
As shown in FIG. 3, the core main body 5 has a substantially U-shape having a pair of legs 5a, 5b, and both legs 5a, 5.
The coil 4 is assembled with a substantially C-shaped core auxiliary part 6 arranged so as to come into contact with the end face of the core body 5, and is tightened by a knob 7.
Before the core auxiliary part 6 and the core auxiliary part 6 are combined, the fixing piece 8 is wound around one leg part 5a of the core main part 5 via a fixing piece 8. Here, two screw holes 20 are formed in the outer surface of the other leg portion 5b of the core main body portion 5.

On the other hand, the mold 2 is configured into a box shape with a bottom plate 2a, side plates 3b, and a top plate 2C.

Before assembling the mold 2, the transformer body 1 is placed on the bottom plate 2a of the mold 2 with the other leg 5b of the core main body 5 facing down, with the spacer 21 interposed therebetween, and the screw 22 is fixed on the bottom plate 2a by screwing it into the screw hole 20 through the bottom plate 2a and the spacer 21. Note that the spacer 21 is arranged when the lower surface of the iron core 3 is not exposed to the lower surface of the molded product.
It does not need to be used if it is acceptable for the bottom surface to be exposed.

Next, the side plate 2b of the mold 2 is assembled so as to surround the transformer body 1, and the primary ground terminal 14 and the secondary terminal 15 are attached to the lower part of the inner surface of the side plate 2b, and then the upper plate 2C is assembled. At the same time, a high voltage secondary terminal 16 is attached to the lower surface of the upper plate 2C.

With the transformer main body 1 housed and fixed in the mold 2 in this way, resin is injected from the resin injection port 17 formed in the upper plate 2C, and after the resin is primarily cured, the bottom plate 2a and the side plates of the mold 2 are injected. By removing the upper plate 2b and the upper plate 2C and performing secondary curing, a molded article in which the transformer body 1 is molded with the resin 18 as shown in FIG. 4 is manufactured.

Then, by attaching the base 19 to the bottom of this molded product, the voltage transformer A having a resin molded grounding surface is completed.

[Effects of the Invention] The method of manufacturing a resin molded transformer of the present invention provides the following effects.

(1) Since the transformer main body is directly fixed to the mold with screws, the transformer main body can be securely fixed to the mold. Therefore, even if the mold is tilted during injection of resin, the main body of the transformer will not be displaced, which increases the degree of freedom in the injection direction of the resin and the configuration of the transformer.

(2) Furthermore, since the transformer main body can be fixed simply by tightening the screws, the fixing work can be done easily.

(3) Since the space between the other leg of the main body of the core and the coil is entirely molded with resin, there is no need to increase the dimensions for insulation between them, making it possible to reduce the size and weight. Become.

(4) Furthermore, since special parts such as clamps and insulating plates are not required, the number of components can be reduced and the configuration can be simplified.

[Brief explanation of drawings]

1 to 3 show an embodiment of the present invention, in which FIG. 1 is a longitudinal sectional front view of the transformer main body housed and fixed in the mold, FIG. 2 is a longitudinal sectional side view of the same state, and FIG. FIG. 3 is a perspective view of a split type iron core. FIG. 4 is a perspective view of a potential transformer with a resin molded grounding surface. 5 to 7 show conventional examples, where FIG. 5 is a view equivalent to FIG. 1, FIG. 6 is a view equivalent to FIG. 2, and FIG. 7 is a perspective view of the clamp. In the drawing, A = 1 transformer (resin mold transformer),
1 is the transformer main body (transformer main body), 2 is the mold type, 3 is the split type core, 4 is the coil, 5 is the main body of the core, 5a, 5
b are the legs, 6 is the core auxiliary part, 17 is the resin injection port, 1
8 is a resin, 20 is a screw hole, and 22 is a screw.

Claims (1)

[Claims] 1. A split core configured by combining an approximately U-shaped core main body having a pair of legs and a core auxiliary part arranged so as to abut on the end faces of both legs, and one of the core main bodies. A resin molded transformer is manufactured by having a transformer body consisting of a coil wound around the legs, and injecting resin into the mold with the transformer body housed and fixed in the mold. In the method, a screw hole is formed in the other leg of the core main body, and a screw is screwed into the screw hole through the mold while the transformer body is housed in the mold. A method for manufacturing a resin mold transformer, characterized in that it is fixed in a mold.