JPH0745465A - Method and apparatus for forming resin molded coil - Google Patents

Abstract

PURPOSE:To provide a new positioning means of a coil conductor employed in resin molding of the coil in which no spacer is employed for ensuring the thickness of insulation. CONSTITUTION:When a coil conductor 1 set in a metal mold 3 is molded by thermally curing a resin 4 filling thereabout, electromagnetic coils 6, 7 are disposed on the opposite sides of the metal mold and the coil conductor is secured at in place through the use of repelling electromagnetic force being generated upon conduction of the coil conductor and the electromagnetic coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a polymer material, and more particularly to a method of molding a thermosetting resin such as an epoxy resin having a conductor winding inside.

[0002]

2. Description of the Related Art Molded coils in which windings are molded with epoxy resin or the like are widely used in electric power equipment because they are excellent in insulation performance, mechanical characteristics, and moisture resistance. It is particularly suitable for devices that require high performance, such as those that are charged with a high voltage. Such a mold coil is usually used after setting the coil conductor in the mold.
A thermosetting resin such as an epoxy resin is injected and cured by heating to be molded. In such a case, it is usual to provide a proper number of spacers between the mold and the coil conductor to secure a predetermined insulation thickness. However, in the method using such a spacer, there is a concern that defects such as peeling may occur at the spacer interface and various characteristics such as insulation characteristics may be deteriorated. Therefore, the shape and material of the spacer have been devised as described in JP-B-58-042609. Further, as described in Japanese Patent Laid-Open No. 4-239704, measures have been taken such as providing a reinforcing material at a contact portion with a mold and treating a spacer interface. However, even such a method could not be a complete countermeasure in the case of molding in a shorter time. In addition, such a method of attaching the spacers has a drawback that the work for the attachment is inevitable and the number of work steps is increased.

[0003]

SUMMARY OF THE INVENTION The object of the invention is to fundamentally solve the disadvantages of the spacers mentioned in the prior art.

[0004]

DISCLOSURE OF THE INVENTION The present invention focuses on the fact that the occurrence of defects in the prior art is due to the spacer used to secure a predetermined insulation thickness, and a new conductor not relying on the spacer is provided. The positioning means is directed. For that purpose, electromagnetic coils are provided on both sides of the coil conductor, the coil conductor is also energized, the coil conductor is fixed at a predetermined position by the electromagnetic force acting on these, and a predetermined insulation thickness can be secured without using the spacer. I did it.

[0005]

In this method, since the spacers which are likely to cause defects are not used, the defects around the spacers described in the prior art are completely eliminated.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. The present invention can be applied to any coil having a shape close to a plane regardless of the shape viewed from the opening side of the coil, but here, a circular coil will be described as an example. FIG. 1 is an embodiment of the present invention. FIG. 2 is a cross-sectional view as seen from the side surface side. The coil conductor 1 is formed by winding an insulated electric wire coated with an insulation coating or winding a bare electric wire a predetermined number of times with an appropriate insulator interposed. Two
Are the terminals and lead wires. Coil conductor is mold 3
Set in. Although the details are not shown in the figure, the mold is
The device is devised so that the coil conductor can be loaded and unloaded appropriately by dividing into a plurality of parts. A non-magnetic material such as aluminum or stainless steel is used as the material of the mold. In this case, since the weight of the coil is supported by the terminal and the lead wire, the terminal and the lead wire 2 are designed to have strength for supporting the terminal and lead wire and rigidity for determining the coil position of the cross section shown in FIG. Need to Electromagnetic coils 6 and 7 are arranged on both sides of the mold as shown in FIG. The shape of this electromagnetic coil does not necessarily have to be the same as the shape of the coil conductor in the mold, but it is desirable that the shape be as close as possible to the same shape.
The number of turns of the electromagnetic coil and the energizing current are designed in consideration of the size and weight of the coil conductor to be loaded therein so that an electromagnetic force sufficient to fix the coil conductor in place is generated. It After arranging in such a configuration, after injecting the resin 4 into the cavity of the mold or injecting the resin,
The electromagnetic coils are arranged as shown. In this state, a current is applied to the coil conductors, and a current is applied to the electromagnetic coils 6 and 7 from an energization device 9 (not shown in FIGS. 1 and 2). The energizing power source may be alternating current, but it is preferable to use a direct current power source. When using an AC power supply, it is necessary to use a non-magnetic and non-conductive one such as FRP type. When energizing, the polarity of the current and the direction of the energizing current to each winding are set so that the electromagnetic coils and the coil conductors always repel each other. For example, in FIG. 1, when a current is passed so that the left side (coil conductor side) of the electromagnetic coil 6 becomes the N pole, the right side (electromagnetic coil 6 side) of the coil conductor is energized so as to become the N pole. 7 on the right side (conductor coil side)
Is passed through so that it becomes the S pole (the S coil is on the left side of the opposing coil conductor). Now, assuming that the electromagnetic coils 6 and 7 have the same number of turns and the same energization current and are arranged at positions symmetrical with respect to the coil conductor, the coil conductor 1 receives substantially equal repulsive electromagnetic force from the electromagnetic coils on both sides, As a result, it is fixed in the center of the mold. This repulsive force is roughly given by the following equation, assuming that the distance between the coil conductor and the electromagnetic coil is extremely short compared to the diameters of the coil conductor and the electromagnetic coil.

[0007]

[Equation 1] F = μ ₀ rI ₁ I ₂ N ₁ N ₂ / d (Equation ₁ ) where μ ₀ : permeability of vacuum, r: radius of coil I ₁ , N ₁ : current flowing to coil conductor and the coil conductors of the turns I _2, N _2: the energizing current and the electromagnetic coil of the electromagnetic coil turns d: now the distance between the coil conductor and the electromagnetic coil, assuming the following values also can there be sufficient actual molded coil, repulsive A force value of about 630 (N) is obtained.

Calculation conditions: r = 0.5 m, I ₁ = 100
A, I ₂ = 100A, N ₁ = 100 times, N ₂ = 100
Time, d = 0.1 m This electromagnetic force value is sufficient for fixing the coil conductor, which is the object of the present invention, to the center of the mold as shown in FIG. It is possible to secure a predetermined insulation thickness without using the spacer.

In a usual molded coil, as in the above-described example, the coil conductor is often located in the center of the mold to make the insulation thickness on both sides equal. In this case, the electromagnetic coils on both sides may be arranged at positions symmetrical with respect to the center axis of the mold and at positions close to the mold, and control of the energizing current is not necessarily required. However, when the shape of the coil conductor is not the target or the left and right insulation thicknesses are not equal, a sensor 8 for detecting the position of the coil conductor is provided inside or outside the mold as shown in FIG. It is also possible to control the energizing current of each electromagnetic coil while monitoring the coil conductor position by the sensor output so that the coil conductor is fixed at a predetermined position.

3 to 5 show an example of a method of energizing the electromagnetic coil. FIG. 3 shows a coil conductor and each electromagnetic coil provided with an individual energizing device.
Shows that an independent power source is provided for the coil conductors and a common power source is used for the two electromagnetic coils. Also, in FIG. 5, all the three coils are supplied with current from a common energization device. . Usually, the conductor is energized by using the heat generated from the conductor and often also serves as a heating source when the resin is cured. In such a case, FIG. 3 or FIG. 4 may be used. When the coil conductors have the same insulation thickness on both sides and the coil conductor is to be arranged in the center of the mold, the circuit of FIG. 4 in which a common current is passed through the electromagnetic coil is suitable. Further, when the energizing current is controlled according to the output of the position detecting sensor of the coil conductor described in FIG. 1, the circuit of FIG. 3 is used.

FIG. 6 shows a modification of the present invention and is a vertical sectional view similar to FIG. Thus, the present invention is shown in FIG.
Instead of using the electromagnetic coil having the same size as the coil conductor shown in, the iron cores 10 and 11 having the shape shown in FIG. 6 are used.
The magnetic flux generated in the exciting coils 12 and 13 may be guided to the vicinity of the coil conductor. Also in this case, the direction of the current must be determined so that a repulsive electromagnetic force is generated between the coil conductor and each electromagnetic coil. By doing so, the exciting coil can be made common to the coils having different shapes only by changing the iron core.

As described above, according to this embodiment, a molded coil having a predetermined insulating thickness can be molded without using a solid spacer, so that a molded coil having no defects and high reliability can be obtained.

The present invention can be applied even when a thermosetting resin other than the epoxy resin is used.

[0014]

According to the present invention, since it is possible to perform molding without using a spacer, it is possible to perform molding without defects, and it is possible to provide a highly reliable coil molding method and its manufacturing apparatus.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

2 is a cross-sectional view of FIG.

FIG. 3 is a circuit diagram showing a method of energizing each coil according to the present invention.

FIG. 4 is a circuit diagram showing a method of energizing each coil in the present invention.

FIG. 5 is a circuit diagram showing a method of energizing each coil according to the present invention.

FIG. 6 is a vertical cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

1, 1C ... Coil conductor, 2 ... Terminal and lead wire, 3 ... Mold, 4 ... Resin, 5 ... Energizing device, 6, 7, 6C, 7C ...
Electromagnetic coil, 8 ... Coil position detection sensor, 9 ... Electromagnetic coil energizing device, 10, 11 ... Iron core, 12, 13 ... Excitation winding, 9a, 9b ... Electromagnetic coil energizing device.

Claims (3)

[Claims] 1. A method in which a coil conductor constituted by winding a conductor is loaded into a mold, a thermosetting resin is injected, and the resin is heat-cured, and the coil conductor is energized to both opening surfaces of the coil conductor. A resin molding coil molding apparatus, characterized in that magnetic field generating means are provided at opposing positions. 2. The molding apparatus for a resin mold coil according to claim 1, wherein a pair of electromagnets or a pair of permanent magnets are used. 3. The mold according to claim 2, wherein the mold is provided with at least one sensor for detecting the position of the coil conductor, and the current supplied to the coil conductor or the electromagnet corresponding to the output of the sensor is provided. A method of molding a resin mold coil, wherein either or both of the exciting currents are controlled.