JPH04101651A - Insulating method of coil for electric appliance - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to a method of insulating coils for electrical equipment such as stator coils of AC motors, armature coils of DC motors, and field coils. be.

(Prior Art) As a method of insulating coils for rotating electric machines, a method is widely used in which, for example, a mica tape is wound around the coil, the tape is impregnated with epoxy resin under vacuum pressure, and the tape is heated and cured.

In this method, during the heating process from impregnating the epoxy resin to heating and curing it, the viscosity decreases due to the temperature characteristics of the resin, and the resin impregnated into the insulating layer flows out before it hardens, creating voids between the insulating layers. There is a problem in that it forms and deteriorates the insulation performance.

Therefore, in order to prevent these impregnated resins from flowing out, conventional methods have been used, such as adding a curing catalyst to the resin to shorten the time for the resin viscosity to decrease, and heating and curing while rotating with a single-rotation device. Ta.

(Ill! problem that the invention seeks to solve) However,
In the above conventional method, the pot life of the resin remaining in the impregnation tank is significantly shortened by the curing catalyst, which causes problems in repeated use, is economically disadvantageous, and increases the manufacturing cost of coils for electrical equipment. It was also the cause.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method of insulating a coil for an electric device, which prevents the resin impregnated into an insulating layer from flowing out during heat curing and extends the life of the resin.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides for the surface of a base material bonded to a backing material with an adhesive.
A dispersion of a capsule-shaped curing catalyst, which is made by enclosing a curing catalyst in a heat-melting capsule, is applied and dried, and the obtained insulating tape is wound around a coil, which is made of a thermosetting resin and an acid anhydride curing agent. It is impregnated with resin and cured by heating.

(Function) When a coil wound with insulating tape is impregnated with a resin consisting of a thermosetting resin and an acid anhydride curing agent and cured by heating, the capsules of the capsule-shaped curing catalyst coated on the insulating tape dissolve. , the enclosed curing catalyst dissolves in the resin and accelerates curing, preventing the resin from flowing out during heating and curing.
Eliminates the occurrence of voids that degrade insulation performance in the insulation layer.

In addition, we aim to extend the life of the resin remaining after impregnation, so that it can be used repeatedly without any problems.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing the structure of an insulating tape used in an embodiment of the present invention, and FIG. 2 is a sectional view of an insulated coil to which an embodiment of the present invention is applied.

First, the insulating tape 1 uses a polyimide film with a thickness of 0.025+In as the backing material 2, as shown in FIG.
A laminated mica with a thickness of about 0.13 mm is used as the base material 3, and these are bonded with an epoxy ester varnish TV B 20 that is an adhesive.
09 varnish (a product of Toshiba Chemical Co., Ltd.) 4, and a curing catalyst Tsubacure HX3742 (a product of TF!A Kasei Kogyo Co., Ltd.) 5, which is a capsule-shaped curing catalyst dispersed in toluene, was applied to the surface of the base material 3. It was manufactured by drying it at 80°C for 3 minutes to volatilize it. Its constituent ratios are: aggregate mica 78.93 wt%, polyimide film 13.27 wt%, adhesive 7.5 wt%, and capsule-shaped curing catalyst 0.3 wt%.

The insulating tape 1 thus produced is wound around a coil 8 using a glass winding for the insulated wire 7 of the insulated coil 6 shown in FIG. 2, to form an insulating layer 9.

Next, the insulated coil 6 is coated under vacuum with 60wt% of epoxy compound TVB 2603 resin (product of Toshiba Chemical Co., Ltd.) as the main ingredient and TVB 2 with acid anhydride-based curing agent.
604 (product of Toshiba Chemical Co., Ltd.) Impregnated with 40 wt% of resin, further pressurized, and then heated and cured.

In the insulated coil manufactured as described above, the resin near the curing catalyst quickly becomes the B stage, and the resin in the slow reaction area is trapped by the resin that has already become the B stage and is prevented from flowing out.

On the other hand, it was confirmed that there was no difference in the resin remaining in the impregnation tank after impregnation by measuring the gelation time before and after impregnation.
We were able to prove that it is not affected by pot life.

As a conventional example, a polyimide film with a thickness of 0.025 m was used as the backing material, and laminated mica with a thickness of about 0.13 m was used as the base material, and this was coated with epoxy ester varnish TVB2009.
An insulating tape laminated with varnish (a product of Toshiba Chemical Co., Ltd.) is wound around a coil in the same manner as in the above example, and 0.3 νt% of an amine curing catalyst TVB2605 (a product of Toshiba Chemical Co., Ltd.) is added to the same resin as in the example. They were blended, impregnated under vacuum, pressed and then heated and cured.

As a result, good insulation properties similar to those of the example were obtained, but
The pot life of the resin remaining in the impregnation tank was reduced to 174 in the example.

Further, as a comparative example, the insulating tape shown in the conventional example was used and wound around a coil in the same manner as in the conventional example, impregnated with the same resin as in the example under vacuum, and then heated and cured after being pressurized.

Comparing the characteristics of this comparative example with the examples, it is found that the viscosity of the resin impregnated in the insulating layer decreases and flows out when cured by heating.
It was observed that many voids were formed.

FIG. 3 shows the tan of the above-described embodiment, conventional example, and comparative example.
δ - Voltage characteristics are shown, where A shows the example, that is, the characteristics when using an insulating tape coated with a capsule-shaped curing catalyst, and B shows the conventional example, that is, the characteristic when using a resin containing a curing catalyst. This shows the characteristics when impregnated with C.
shows the characteristics of a comparative example, that is, a case where neither the insulating tape nor the impregnated resin contained a curing catalyst.

Furthermore, Fig. 4 shows the results of measuring the viscosity of the resin remaining after vacuum impregnation in the above-mentioned Examples, Conventional Examples, and Comparative Examples, where A represents the Example, B represents the Conventional Example, and C represents the Comparative Example. ing.

It can be seen from FIGS. 3 and 4 that the characteristics of the example are superior to those of the conventional example and comparative example.

Note that 2. Insulating tape 1 is made by bonding laminated mica and glass cloth, laminated mica and heat-resistant film, laminated mica glass cloth and heat-resistant film, etc. with an adhesive made of an epoxy resin compound, and applying toluene as a capsule-shaped curing catalyst on the surface of the base material. Any material that has been coated with a dispersion and dried may be used. In addition, the capsule of the capsule-shaped curing catalyst is made of polyethylene, polypropylene, isomyanate, polycarbonate resin, or a compound thereof, which does not swell or dissolve in the dispersion liquid, and which dissolves by the heat during heating and curing of the impregnated resin. That's fine. Further, as curing catalysts, imitazoles, amines such as DMP-30, and 8F3-amiaducts are generally used.

〔Effect of the invention〕

As explained above, according to the present invention, the action of the curing catalyst sealed in the heat-melting capsule applied to the insulating tape prevents the resin impregnated into the insulating layer from leaking during heat curing and eliminates voids. It is possible to provide a method of insulating coils for electrical equipment that eliminates the occurrence of curing and has a long life without being affected by the curing catalyst for the remaining resin.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the structure of an insulating tape used in an embodiment of the present invention, FIG. 2 is a cross-sectional view of an insulated coil to which an embodiment of the present invention is applied, and FIG. 3 is an embodiment of the present invention. Fig. 4 shows the viscosity of the resin remaining after impregnation in one embodiment of the present invention together with the viscosity of the conventional example and comparative example. FIG. 1... Insulating tape 3... Base material S... Curing catalyst 7... Insulated wire 9... Insulating layer 2... Backing material 4... Adhesive 6... Insulated coil 8... coil

Claims (1)

[Claims] A dispersion of a capsule-shaped curing catalyst, which is made by enclosing a curing catalyst in a heat-melting capsule, is applied to the surface of the base material bonded to the backing material with an adhesive, and the resulting insulating tape is wound into a coil. A method for insulating coils for electrical equipment, which comprises: rotating a coil, impregnating it with a resin made of a thermosetting resin and an acid anhydride curing agent, and curing it by heating.