JPH0754983Y2 - Winding structure of mold transformer - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to a winding structure of a mold transformer in which a prepreg material used for molding a winding of a mold transformer is selectively used according to the heating and hardening temperature of the winding. Regarding

B. Overview of the Invention The present invention is a molded transformer using a prepreg material, in which a high-flow prepreg material is used inside and inside the winding, and a low-flow prepreg material is used around the winding. By winding each, the inner circumference where it is difficult for the temperature to rise,
Since the prepreg materials suitable for the inside and the outer circumference where the temperature rises rapidly are applied, the heat treatment can be performed in a short time.

C. Conventional technology and its problems When manufacturing a molded transformer, when molding the winding without using a mold, the prepreg material is used for the inner circumference of the winding.
There is a method of wrapping around the outer circumference and the inside of the winding and hardening by heating.

In this case, the work of fitting the iron core into the winding or the work of fitting the winding into the iron core is omitted to reduce the number of steps, and the size is reduced without the need for fitting between the iron core and the winding. Therefore, a means of winding the prepreg material and the winding wire directly on the iron core leg is adopted.

However, in the case of directly winding such a prepreg material, in the step of heating and curing the prepreg material wound around the iron core leg with a heating device, when the thermal time constant of the iron core leg is large, the outer circumference of the winding is rapidly increased. It is easy to raise the temperature, but it takes a long time to raise the inner circumference and the inside of the winding to a temperature sufficient for curing the prepreg material.

Therefore, even if the winding is directly wound around the iron core leg to reduce the number of fitting steps, it takes a long time to cure the prepreg material, and the effect of reducing the number of steps is impaired.

In view of the above-mentioned problems, the present invention provides a winding structure for a mold transformer that shortens the curing time of the prepreg material.

D. Means for Solving the Problems The present invention which achieves the above-mentioned object is based on the fact that a prepreg material having different properties is selectively used for winding depending on the portion of the winding.

E. Action A low-flow prepreg material that melts at low temperature where the temperature rises is low and a low-flow property that melts slowly even at high temperature is wound, and the resin is cured for the same time. It was designed to be done.

F. Embodiment An embodiment of the present invention will now be described with reference to FIGS. FIG. 1 is a partial cross section of a molded transformer,
It shows an iron core leg and a winding.

That is, the winding 2 is directly wound around the iron core leg 1. In other words, between the iron core leg 1 and the winding 2, in other words, the inner circumference of the winding 2, in other words, inside the winding, A semi-cured prepreg material is wound around the outer circumference of the winding 2. Specifically, a glass-based epoxy resin prepreg material or a glass-based polyimide resin prepreg material is used.

Among them, the prepreg material 3a on the outer peripheral side of the winding 2 has a low flow property. That is, the prepreg material is that the resin is once melted (gelled) by heating and then hardened, but the low-flow one is melted and hardened even at a high temperature as shown in FIG. It has a slow speed (the resin flow test value of JIS C6487-1980 is 5% or less).

On the other hand, the prepreg material 3b used for the inner circumference of the winding 2 and the inside of the winding 2 has a high flow property. That is,
As shown in FIG. 2, a resin having a high flow property is one in which the resin melts (gelates) and cures even in a low temperature region (the resin flow test value is 10% or more).

Thus, when a resin having a low flow property is used on the side close to the winding surface, the resin is slow to melt even if the surface side temperature of the winding 2 is rapidly raised for hardening in a short time. When a high flow resin is used for the side, the resin melts even at a low temperature, the resin of the entire winding melts with a slight time lag, and curing begins, and curing is completed in a short time as a whole.

The above description has been made on the assumption that the winding is wound directly on the iron core, but the proper use of the prepreg material can be applied to other than the structure for directly winding the winding.

Further, in the above embodiment, the prepreg material other than 3a has a high flow property, but it is naturally possible to make the prepreg material near the outer circumference of the winding having a low flow property in accordance with the temperature rise. is there.

G. Effect of the Invention As described above, according to the present invention, by using prepreg materials having different properties (flow characteristics) on the winding surface, the inner circumference of the winding, and the inside of the winding, heat hardening can be performed in a short time. Since it is possible to finish the work, and the time required for heating (hardening / fitting / positioning) can be shortened as well as the heat-hardening time can be shortened, the overall manufacturing man-hour can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an embodiment of a molded transformer, FIG.
The figure is a temperature rise curve diagram of the outer circumference and the inner circumference of the winding. In the figure, 2 is a winding wire, 3a is a low-flow prepreg material, and 3b is a high-flow prepreg material.

Claims (1)

[Scope of utility model registration request] 1. In a winding structure in which a coil is wound directly around an iron core, a predetermined prepreg material is wound around the outer circumference of the winding, and melted inside and inside the winding at a lower temperature than the prepreg material on the outer circumference of the winding. A winding structure for a molded transformer, which is obtained by winding a high-flowing prepreg material.