JPS61177702A - Mold coil - Google Patents

Abstract

PURPOSE:To improve reliability at a low cost and to promote miniaturization by using an insulating cylinder in which epoxy processing glass base material and paper base material are alternately piled, and by making good use of respective characteristics of the glass base material and the paper base material. CONSTITUTION:An insulating cylinder 11 is unified by heat-hardening after an epoxy processing glass base material 11a and an epoxy processing paper base material 11b are alternately piled. As an injecting resin 2 is tightly adhere- hardened to the epoxy processing glass material 11a, separation of a mold interface 5 is prevented to a heat cycle in mold coil welding. An insulating distance needed between a low pressure coil 9 and a coil conductor 3, that is to say, a dimension A between coils is reduced smaller than the conventional one by eminent through pressure of the epoxy processing paper base material 11b.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a molded coil, and particularly to a molded coil wound as a conductive coil using an insulating tube as a winding core.

[Conventional technology]

Figure 2 shows a conventional molded coil, in which (1) is an insulating tube around which a coil conductor (3) is wound, and the molded resin (C) and insulating tube (1) are used to protect the coil conductor (3) and interlayer insulation. It wraps a coil formed of a material (1), maintains the insulation of the high voltage coil (generally higher than j kV), and mechanically integrates the coil firmly. It is also possible to include the entire coil with casting resin (2), but the insulating tube (1) is made of casting resin (2).
) also serves as a panel to determine the inner diameter of the coil when injecting the liquid.

The bottom surface is determined by each board. Casting resin (
When casting the coil outer diameter surface (6
) and the reduced thickness provided on the lower surface of the coil, the coil and glabellar insulator (glabella) are set, and a molded coil is formed by injecting liquid Kl casting resin (c) and heating and hardening it. 1) indicates the mold interface, 2) indicates the air duct, and 1) indicates the support member for the low-voltage coil (9).

As casting resin (2), epoxy resin is generally blended with silica, alumina, etc. to improve mechanical strength after heat curing, but there are problems such as generation of heat during resin curing reaction, shrinkage of resin during curing, etc. In consideration of this, the insulating tube (1) must have heat resistance of class B or higher and good adhesion to the casting resin (2), so epoxy glass laminated tubes are generally used. Ta. In addition, the lightning impulse withstand voltage of an A kV class molded transformer is 60%, and high electrical stress is applied between the coil dimensions (A), so the insulating tube (1)
A high penetration voltage is required between the low voltage coil (9) and the coil conductor (3).

Conventional insulating tubes (1) have been made of epoxy glass laminated tubes in order to withstand the above functions, but glass laminated tubes generally have a low withstand voltage, so it is necessary to have a sufficiently large dimension (A) between the coils. ·be. On the other hand, an insulating cylinder made of a paper tube with a high withstand voltage may also be considered, but the mechanical strength would be poor. Not only during hardening of the coil, but also when heat sapping,
In order to withstand cycles, heat shocks, etc., and to prevent peeling, especially at the mold interface (&) where the casting resin contacts the insulating tube, it is better to use a glass cloth laminated chain for stronger adhesion. We have no choice but to rely on glass laminated tubes with low penetration pressure resistance. Therefore, it has been impossible to reduce the inter-coil dimension (A) for reasons of insulation rather than cooling.

[Problem that the invention seeks to solve]

Conventional molded coils as described above have problems such as poor economic efficiency and reliability, such as the inability to satisfy the requirements of penetration pressure resistance, mechanical strength, and thermal strength, and the inability to reduce the dimension between the coils. Ta.

This invention was made to solve these problems, and has high penetration pressure, excellent mechanical strength and thermal strength, and allows for reduction of the dimensions between coils, and is economical and reliable. The purpose is to obtain an excellent molded coil.

[Means for solving problems]

The molded coil according to the present invention has a structure in which an insulating cylinder serving as a winding core of a coil conductor is integrated with an epoxy-treated glass base material and an epoxy-treated paper base material stacked alternately.

[Effect]

This invention has excellent adhesion between the insulating tube and the casting resin at the mold interface, and mechanically, the strength of the epoxy-treated glass substrate prevents succinic acid from forming with the casting resin. It functions as a coil conductor, and the excellent voltage resistance of the epoxy-treated paper base material is utilized for insulation purposes.

〔Example〕

FIG. 1 shows an embodiment of the present invention, in which an insulating cylinder (ll) is made by stacking an epoxy-treated glass base material (lla) and an epoxy-treated paper base material (llb) alternately and integrating them by heat curing. It is what it is. The same reference numerals as in FIG. 2 indicate the same parts.

With the above configuration, the casting resin (co) is firmly adhesively cured with the epoxy-treated glass base material (lla), so the mold interface (
5) Huccinic acid is prevented. In addition, the insulation distance required between the low voltage coil (9) and the coil conductor (J), that is, the inter-coil dimension (A), is the epoxy-treated paper base material (ttb
) can be downsized compared to conventional ones due to the reduced penetration pressure.

In the molded coils of transformers used in high voltage circuits of 3 k'/class or higher, internal stress is generated due to differences in linear expansion coefficients of constituent materials due to temperature changes during energization, shrinkage during resin curing, etc. It is necessary to prevent the occurrence of cracks at the mold interface (5).In particular, since the molded coil is directly exposed to the surrounding atmosphere, the conductor surface is covered with an insulator with excellent insulation properties to prevent cracks from occurring due to energization and one cycle. Must. In this regard, as described above, the insulating cylinder (ll) used as the casting mold for the molded coil and as the 8 shape for coil winding is made of an epoxy-treated paper base material (llb) with excellent withstand voltage. The above functions are achieved by alternately stacking the epoxy-treated glass substrate (lla), which has excellent adhesion with the molded resin (c) and having excellent mechanical strength, and curing it with heat to form an integral piece. .

In addition, in the unlikely event that the air duct (ri) is ionized due to lightning impulse penetration, the insulating tube (1) facing the air duct (7)
Even if the surface of 1) is contaminated, the surface after coil casting is contaminated, or there is condensation, the mold interface (3) will not peel off and the insulation performance will be maintained due to the excellent withstand voltage of the insulating tube (ll). The coil-to-coil dimension (A) can be reduced.

In addition, in the above example, the epoxy-treated glass base material (/ /a) is placed facing the casting resin (2), but
Epoxy treated paper base (llb) facing the casting resin (2)
Even if the glass cloth is placed on the surface of the paper base material, the unevenness of the glass cloth is transferred to the surface of the paper base material, so that the adhesion with the casting resin (C) is good and the same effect can be obtained.

〔Effect of the invention〕

As described above, the present invention provides an epoxy-treated glass base material,
Since we use an insulating tube made of alternating layers of paper base materials, we can take advantage of the respective features of the glass base material and paper base material, resulting in low cost, improved reliability, and the ability to achieve smaller size. .

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view of an embodiment of the present invention, and FIG. 2 is a partial cross-sectional view of a conventional molded coil. (K)...Casting resin, (3)...Coil conductor, (11)
...Insulating tube, (//a)...Epoxy treated glass base material,
(#b)...Epoxy treated paper base material. In each figure, the same reference numerals indicate the same or corresponding parts. +1n Upstairs ~ -1 "Costum 2 l-411: Hasibaku Drips Map

Claims (3)

[Claims] (1) In a molded coil in which a coil conductor is wound around an insulating cylinder as a winding core and integrated with casting resin, an epoxy-treated glass base material and an epoxy-treated paper base material are alternately stacked and heat-cured together. A molded coil comprising the insulating tube as described above. (2) The molded coil according to claim 1, comprising an insulating tube that also serves as a casting mold on the inner diameter side of the casting resin. (3) The molded coil according to claim 1, wherein a low-voltage coil is disposed facing the inner surface of the insulating cylinder via an air duct.