JPS6314422Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulating cover for a transformer, and in particular, to ensure a creepage distance between the primary coil and secondary coil of the transformer.

FIG. 1 shows transformer bobbins used conventionally and in the present invention. That is, Figure 1A
B shows an external view of the drum-shaped bobbin, and B shows a sectional view thereof. That is, the winding trunk 10 is provided with a narrow trunk 10a, and the primary coil 20 and the secondary coil 21 are wound around the narrow trunk and the winding trunk, respectively. In the figure, 17a and 17b are the terminals of the primary coil,
In other words, it is a connection pin that fixes the starting end, end, or intermediate tap of the coil by soldering, and also serves as a connection port to the outside. 11 is the flange of the bobbin, 15a is a guide groove for guiding the end of the primary coil to the connection pin, and 15b is a guide groove for the secondary coil wound on the outside of the winding drum. be. Note that 12 is a through hole in the core.

However, to explain the conventional means for winding the primary and secondary coils on the bobbin, the second
In Figure A, the primary coil 20 is wound around the bobbin, and its starting end 20a and terminal end 20b are connected to the guide groove 15.
Fig. 3 is an external view of the connection pin 17a connected to the connection pin 17a through the connection pin 17a and an insulating tape 30 wrapped thereon;
Wrap the secondary coil directly on the insulating tape 30,
The terminal is connected to the lower connecting pin 17b (not visible in the figure), and the core is installed in the through hole 12 of the bobbin to form a transformer.

However, with insulation using only such insulating tape 30, there is a gap between both coils, especially the primary coil 2.
The creepage distance between the connecting portions of the terminals 20a and 20b of 0 to the connecting pin 17a and the secondary coil 21 becomes small, which causes an insulation problem. Therefore, B in the same figure,
The above-mentioned creepage distance is increased by abutting an insulating paper 31 bent into an L-shape as shown in C, and wrapping the secondary coil 21 over it.

However, the work of attaching L-shaped insulating paper to each lead-out portion of the terminal of the primary coil 20 to the connecting pin 17a is very labor-intensive and difficult to automate, and the effect is only secondary. The insulating paper may shift during coil winding, making it unreliable, and the secondary coil 21 itself also has the drawback of not being able to be wound neatly.

The present invention was made in order to eliminate the above-mentioned drawbacks, and by eliminating the conventional L-shaped insulating paper 31 installed individually and replacing it with an integrally molded insulating cover, it aims at automation and transformers. The purpose is to improve the reliability of

Hereinafter, embodiments of the present invention will be illustrated and described.

FIG. 3 shows an external view A and a sectional view B when the insulating cover 40 according to the present invention is attached to the bobbin. That is, in Figure A, the primary coil 20 is wound around the bobbin as in the case described above, and the terminals (starting end and terminal end) are connected to the connecting pin 17a, and then the insulating tape 30 is wound as before. , attach the insulating cover 40 over it, and install the 2
The transformer winding process is completed by winding the secondary coil, however, for convenience of explanation, the secondary coil is not shown in FIG.

As shown in FIG. 4, the insulating cover 40 is a vacuum-formed synthetic resin molded product having a saddle-like shape as a whole. A fixed part 40d,
One end thereof is integrally molded with the bobbin, and has a rising surface 40b along the flange 11 of the bobbin, and a flat surface 40b bent outward at right angles to that surface and along the side surface of the flange.
The other end of the insulating cover does not have a rising surface and is cut to a length approximately equal to the length of the winding trunk portion 10 of the bobbin. Therefore, by making such an insulating cover in accordance with the shape and size of the bobbin, it is possible to use the insulating cover in accordance with any shape of bobbin. In the above embodiment, the insulating cover is made of synthetic resin and has a flat surface 40a, but it is not necessarily fixed thereto, and can be manufactured by molding insulating paper or the like in other embodiments. The same effect can be obtained by increasing the height of the rising surface 40b by the length of the flat surface 40a instead of having the flat surface 40a. Furthermore, there is no problem even if the above-mentioned rising surface or the like is provided at the other end of the insulating cover. In this embodiment, in order to guide the terminals of the primary coil 20 to the connection pins 17a at both ends, a bent portion 40c is provided on the rising surface 40b of the insulating cover in accordance with the flange surface of the bobbin. If the pin is not used, this part may be omitted.

In summary, the insulating cover 40 according to the present invention has the following features:
It can be manufactured to match the size and shape of the bobbin, it can be easily fitted onto the bobbin, and it has the effect of maintaining the creepage distance between the primary coil and the secondary coil. Further, it is naturally possible to automate the coil winding work, and by using this, it is possible to provide a highly reliable transformer.

[Brief explanation of the drawing]

FIG. 1A is an external view of the bobbin used in this embodiment and the conventional example, FIG. Figure C is an external view of the L-shaped insulating paper.
FIG. 3A is an external view when the insulating cover according to the present invention is attached, FIG. 3B is a sectional view thereof, and FIG. 4 is an external view of the insulating cover according to the present invention. 10... winding trunk, 11... bobbin flange, 12
... Core penetration hole, 15a ... Guide groove for primary coil, 15b ... Guide groove for secondary coil, 1
7a, 17b... Connection pin, 20... Primary coil, 21... Secondary coil, 30... Insulating tape,
31... L-shaped insulating paper, 40... Insulating cover, 4
0a...Flat portion of 40, 40b...Rising surface of 40, 40d...Saddle-shaped fixing portion.

Claims (1)

[Scope of utility model registration request] A transformer insulating cover for insulating a primary coil and a secondary coil wound on a bobbin of a transformer includes a saddle-shaped fixing portion 40d that matches the shape of the winding surface of the primary coil, and at least the bobbin. The rising surface 40b along which the rising surface 40b
Bent portion 40 provided on 0b to match the flange surface of the bobbin
An insulating cover for a transformer, characterized in that the insulating cover for a transformer has the following features and is an integrally molded product having a saddle-like overall shape.