JPH028542B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a field coil, and more particularly to a method for manufacturing a field coil in which a resin-impregnated layer insulator inserted between coil conductors is cured by heating and pressure using a heater. .

A conventional example of a typical rotating field pole is shown in FIG. As shown in the figure, the magnetic pole consists of a field core 1, a ground insulating layer 2 provided on the body, a field coil 3 disposed through the ground insulating layer 2, and a field coil 3 disposed above and below the field core 1. It is made up of an insulating collar 4, etc. Of these, the field coil 3 is formed from a coil conductor 3a and a layer insulator 3b inserted between the coil conductors 3a, as shown in FIG. It is wound from several hundred turns. and layer insulation 3
b is for firmly adhering the coil conductors 3a to prevent deformation due to elongation due to thermal expansion caused by centrifugal force and temperature rise during operation of the field coil 3, and is impregnated with thermosetting resin. is used.

Incidentally, in order to harden the impregnated resin of the layer insulator 3b inserted between the coil conductors 3a, a baking operation is performed using heat and pressure. A method of applying pressure is generally used.
That is, as shown in FIG. 2, this baking operation involves attaching dowels 5 (upper and lower abutments 5a and lower abutments 5b) that do not deform when pressurized above and below the field coil 3.
It is set on the press plate 6, and a top 7 for stroke adjustment of the press is attached on the upper stopper 5a (in this case, the heater 8 indicated by the dotted line in the figure is not inserted). After that, a current is passed through the field coil 3 and the field coil 3 is heated by the Joule heat generated in the field coil 3. However, the heat generated in the field coil 3, especially the heat on the upper and lower end sides, is transferred from the upper and lower pads 5a and 5b. As a result, the temperature of the upper and lower parts of the field coil 3 does not rise, and the layer insulator 3b of the upper and lower parts of the field coil 3 does not rise.
Field coil 3 whose impregnated resin does not harden and is suitable for the purpose
was not obtained. In addition, in the figure, 9 is an insulating material.

As an alternative to this, an oval-shaped heater 8 (see Fig. 3) heated by electricity or steam, indicated by the dotted line in the figure, is attached to the field coil 3 side of the press plate 6, so that the temperature within the field coil 3 varies. A method is used to reduce the If this method is used, the resin will harden uniformly throughout and a satisfactory field coil 3 will be obtained.
The drawback was that it required a large amount of heat because it heated the entire surface.

The present invention has been made in view of the above points,
The purpose is to provide a method for manufacturing a field coil that enables uniform curing of impregnated resin with less electric power.

That is, in the present invention, the heater is formed into a hollow oval shape that is approximately the same shape as one turn of the coil conductor, and an insulating material is interposed between the heater and the press plate to achieve the intended purpose. This is what I did.

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 4 and 5. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted. In this embodiment, the heater 10 is formed into a hollow oval shape that is approximately the same shape as one turn of the coil conductor. In other words, first, a layer insulator is inserted between the coil conductors (see Fig. 6), and then a heater made of an iron core having a shape almost the same as one turn of the coil conductor, that is, a hollow oval shape, is inserted through insulating materials 9 above and below, respectively. Attach 10. After that, an upper overlay 5 is further placed on the outside through an insulating material 9.
A and the lower stopper 5b are attached, and these are set on the press plate 6, and the top 7 is placed on it. Then, the field coil 3 and the heater 10 are connected in series and energized to heat them.

In this way, since we used the hollow oval heater 10 with a shape that is almost the same as one turn of the coil conductor of the field coil 3, only the necessary part of the field coil 3 is heated, compared to the conventional method. Approximately 1/6~
Can be baked and hardened with 1/30th the electricity. By increasing the amount of heat generated by the heater 10 by the amount of heat conducted to the pad 5 side than the amount of heat generated per turn of the field coil 3, the difference between the highest and lowest temperatures in the field coil 3 can be reduced compared to the conventional method. This makes it possible to reduce the hardness to about 1/6 of that of the impregnated resin, which eliminates the uncured portion of the impregnated resin during baking and hardening, and allows uniform hardening.

Note that when the field coil 3 and the heater 0 are connected in series and heated by electricity, the ratio of the cross-sectional area of the heater 10 and the coil conductor is set to 1.1 to 1.8 (cross-sectional area of 10/cross-sectional area of the coil conductor). Good results were obtained. Also, in this way, the field coil 3 and the heater 1
The same result can be obtained by applying electricity to the field coil 3 and the heater 10 separately without adjusting the resistance ratio with respect to 0, and selecting the current value of each.

As described above, in the present invention, the heater is made into a hollow oval shape that is almost the same as one turn of the coil conductor, and an insulating material is interposed between the heater and the press plate, so that only the necessary parts are removed. Since the required amount of heat is generated, there is less variation in temperature within the field coil, and the impregnated resin is uniformly cured with less power, making it possible to uniformly cure the impregnated resin with less power. A method for manufacturing a field coil can be obtained.

[Brief explanation of drawings]

Fig. 1 is a partially vertical front view of a rotating field pole, Fig. 2 is a front view of the field coil when it is baked in a conventional method for manufacturing a field coil, and Fig. 3 is a front view of a conventional method for manufacturing a field coil. FIG. 4 is a perspective view of a heater, and FIG. 4 is a front view of a field coil during firing according to an embodiment of the field coil manufacturing method of the present invention. FIG. 5 is a perspective view of a heater according to another embodiment, and FIG. FIG. 2 is a longitudinal sectional side view of a coil conductor portion of a field coil. 3... Field coil, 3a... Coil conductor, 3b
...layer insulator, 6...press plate, 10...heater.

Claims (1)

[Claims] 1 A layer insulator impregnated with resin is interposed between the coil conductors made of rectangular conductors, and then a heater and a press plate are placed on the top and bottom of the whole, and then the heater is energized and the resin impregnated in the layer insulator is In the method for manufacturing a field coil that is cured by heating and pressure, the heater is formed into a hollow oval shape having approximately the same shape as the coil conductor, and an insulating material is interposed between the heater and the press plate. A method of manufacturing a field coil characterized by the following.