JPS6025017B2 - Manufacturing method for transformer coils - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a transformer coil that is molded with resin in order to obtain waterproofness and moisture resistance, and is an easy-to-use method that uses a simple and inexpensive molding jig. This is what we are trying to provide.

The conventional manufacturing method for transformer coils is the first method.
This was done as shown in Fig. 2.

That is, a coil 3 wound around a coil bobbin 2 having flanges 1 at both ends and a middle portion is placed in the recess 6 of the split molds 4 and 5.
After tightening the split molds 4 and 5 with taper pins, the split molds 4 and 5 are heated to a certain temperature, and as shown in Fig. 2, a resin such as epoxy is injected and hardened by heating. The split molds 4 and 5 were opened to obtain a resin molded transformer coil.

In this method, the split molds 4 and 5 become large, and during child heating,
Because it takes a long time to reach a certain temperature and the mold is a split mold type, resin leaks easily from small gaps, requiring a mold with high precision, and the clamping strength of the split mold is also required. It was expensive.

In addition, in order to improve the mold release between the mold and the resin, it is necessary to provide a certain template layer on the inner surface of the mold, but this mold release layer deteriorates mold release due to changes over time, so correction work is performed. It was also disadvantageous in terms of management, as it was necessary.

The present invention eliminates the drawbacks of the prior art as described above. Embodiments of the method for manufacturing a transformer coil according to the present invention will be described below with reference to FIGS. 3 to 8.

First, as shown in FIGS. 3 and 4, outer metal rings 7 and 8 formed in a substantially U-shape are provided at both ends, and outer collars 7 and 8 are provided with a certain dimension inside the outer metal rings 7 and 8. A coil 12 is wound between inner wires 9 and 10 of a coil bobbin 11 equipped with smaller inner wires 9 and 10, and the coil 12 is formed into a U-shaped cross-section molding jig made of silicone rubber or the like having elasticity and moldability. Press fit into 13. At this time, the molding jig 13 is assembled with only the outer collars 7 and 8 pressed against each other, and the inner collars 9 and 10 and the coil 1
2 is floating above the molding jig 13. As shown in FIG. 5, this is housed in a gutter-shaped fixing frame 14 with a U-shaped cross section, and with the coil holding jig 15 fitted into the center hole of the coil bobbin 11 and fixed, an injection machine 16 is used to inject epoxy, etc. A casting resin 17 is injected, and after the injection is completed, the casting resin 17 is cured by heating to obtain a transformer coil as shown in FIG.

The Western-style resin 17 also enters between the outer flanges 7, 8 and the inner fittings 9, 10 to improve the bonding strength between the coil bobbin 11 and the Western-style resin 17.

Furthermore, since the outer flanges 7 and 8 are nested in the molding jig 13, there is no possibility of resin leakage. Although we have described the coil bobbin 11 having outer metal numbers 7 and 8 and inner flanges 9 and 10, it can be manufactured by the same method even if it has flanges at both ends or has flanges at both ends and in the middle. The effect is the same, only that the binding force between the bobbin and the resin is slightly weakened.

In addition, in FIGS. 7 and 8, a long frame is used as the fixing frame 14, and a large number of molded sashes 13 incorporating coils are housed and all are fixed at once with a coil holding jig 15. This is an example in which the casting resin 17 is injected simultaneously or continuously to improve workability. As described above, the method for manufacturing a coil for a transformer of the present invention allows resin casting to be performed using a molding jig that has moldability and elasticity and a gutter-shaped fixed frame, so the equipment for this purpose is extremely inexpensive, and There is no need for extremely high dimensional accuracy, there is no resin leakage, and the molding jig and fixing frame are both made of thin materials, so the temperature is low enough to heat the casting resin when it hardens. It has many advantages such as easy operation, high bonding strength between the casting resin and coil bobbin, and above all, easy and efficient work, which is extremely advantageous in mass production. It is a big thing.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of one step in the conventional method for manufacturing a transformer coil, FIG. 2 is a sectional view of another step, and FIG. 3 is a step in the method of manufacturing a transformer coil according to the present invention. A perspective view, FIG. 4 is a top view of the same, and FIG. 5 is a perspective view of another process.
FIG. 6 is a perspective view of a transformer coil obtained by the same method;
FIG. 7 is a perspective view of one step showing another embodiment, and FIG. 8 is a sectional view of the same. 7, 8... Outer tsuba, 9, 10... Inner tsuba,
11... Coil bobbin, 12... Coil, 13... Molding jig, 14... Fixed frame, 15... Coil holding jig , 16...
- Injection machine, 17... Casting resin. Figure 4 Figure 6 Figure 1 Figure 2 Figure 3 Figure 7 Figure 5 Figure 8

Claims (1)

[Claims] 1. Wind the coil around a coil bobbin with flanges on both ends.
This coil is attached to a U-shaped molding jig that has elasticity and releasability so that only the collar is pressed into contact with the coil, and the coil is housed in a gutter-shaped fixed frame and cast resin is injected and solidified. A manufacturing method for transformer coils.