JPS6057609A - Manufacture of resin-molded coil - Google Patents

Abstract

PURPOSE:To prevent the leakage of impregnated resin and to increase heat resistance and insulating properties by impregnating the resin while applying a cure accelerator to a tape-form insulator only when the insulator forms the insulator of a lower-end or of a periphery of a coil. CONSTITUTION:A coil conductor 11 and a tape-form insulator 12 are wound on a periphery of an insulation cylinder 10 to form a multiplex winding coil 23. The conductor 11 is wound in order to n times. After the insulator 12 is wound repeatedly to form an upper-end insulator 13a, it is wound on a periphery of winding layers of the conductor 11 with lapping and it is wound on a conductor 11n at n times to form an interlayer insulator 15a, and a lower-end insulator 14a subsequently. After completing the predetermined coil winding, the insulator 12 forms a peripheral insulator 16. When the insulators 14 and 16 are formed, a roller 18 is pressed down to apply a cure accelerator 20 to the insulator 12. Next, resin is impregnated in the coil 23 and it is taken out when a sealed layer is formed by the insulators 14 and 16 and an insulation cylinder 10 followed by heating to cure the resin. Thus, the leakage of resin can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a resin molded coil having a multi-turn structure used in molded dry type transformers, reactors, and the like.

[Technical background of the invention and its problems]

Some dry type transformers use resin molded coils in which the coils are impregnated with resin and hardened. Since the entire coil is covered with resin, this resin molded coil has characteristics such as high mechanical strength, excellent moisture resistance, and good insulation against earth, and has been used in large numbers.

There are two methods for manufacturing resin molded coils: the mold method, and the moldless method, which involves impregnating a coil with resin (without using a mold) and curing it without letting the impregnated resin flow out of the coil. The moldless method is widely used because it has advantages such as a greater degree of freedom in design. In the moldless method, as a method to prevent the impregnated resin from flowing out from the coil, a curing accelerator is attached in advance to the insulating layer on the outer periphery of the coil, and the insulating layer is cured during the V74 resin impregnation process to make the resin. In this method, the curing accelerator reacts with the impregnating resin to promote gelation of the resin, forming a sealing layer on the insulating layer, and then the coil can be hardened in a heating oven after the impregnation process is completed. This has the advantage of reducing incidental work and equipment.

On the other hand, studies have begun to consider the use of multi-wound coils, in which a coil conductor and a tape-shaped insulator are combined and wound in multiple layers, as transformer coils. This multi-turn coil is
At the same time, a coil conductor is wound to form a wound layer, a tape-shaped insulating material is wound around the end of the wound layer to form an end insulator, and the tape-like insulating material is wound around the outer peripheral surface of the wound layer. It is manufactured by forming an interlayer insulator and an outermost peripheral insulator. For this reason, multi-wound coils allow automatic winding, in which the entire coil winding process is continuous, and there is no need for a special process for inserting the insulator into the coil. It has the advantage that it is possible to use a shaped insulator and there is no need to create special end insulation.

Therefore, it is conceivable to manufacture the multi-wound coil as a resin molded coil using a moldless manufacturing method using a curing accelerator.

However, simply using a tape-shaped insulator coated with a curing accelerator and impregnating it with sealant once and performing three steps is not enough.

In terms of coil quality, there are the following problems: 1. In multi-wound coils, the upper and lower ends of the coil, the interlayer insulation, and the outer circumference of the coil are all insulated and bonded with a C hardening accelerator. The curing speed of the impregnated paste inside the coil conductor is different from that in the vicinity of the coil conductor and in the insulation part between the coils, resulting in an uneven hardening rate as a whole.

If the attenuated resin hardens unevenly in each part of the coil, curing shrinkage can cause whiskers, residual stress can cause resin peeling, and many insulation defects can occur, leading to partial discharges and other problems. This may cause a decrease in dielectric breakdown voltage.

Furthermore, in order to prevent the impregnated resin from leaking from the coil, the tape-shaped insulator is treated with a curing accelerator, and the larger the amount, the worse the heat resistance. FIG. 1 shows the temperature characteristics of a curing accelerator attached to a tape-shaped insulator at a temperature of +17 - α. In this experiment, a glass tape was used as the tape-shaped insulator, and the curing accelerator was IB2MZ (1-benzyl-2-methylimidazole) diluted with alcohol. The glass tape was immersed in this solution and then air-dried to produce a coil. . As shown in FIG. 1, the more the curing accelerator is added, the worse the heat resistance is. However, without a curing accelerator, the impregnated resin will leak during curing. Therefore, a curing accelerator must be used at the expense of heat resistance, and in this case, the cross-sectional area of the coil conductor is increased to reduce heat generation, resulting in a larger coil.

[Purpose of the invention]

The present invention has been made in view of the above circumstances.

The present invention provides a method for manufacturing a resin-molded coil that is a multi-wound coil using a tape-shaped insulator and has few insulation defects and no problems in heat resistance.

[Summary of the invention]

The method for manufacturing the resin mold fill of the present invention is as follows.

A conductor and a tape-shaped insulator are wound to form a multi-wound coil, and a curing accelerator is attached to the tape-shaped insulator only when the tape-shaped insulator is winding the lower end insulator and the outer peripheral insulator, Thereafter, the coil is impregnated with resin, and when the sole layer is formed on the part of the tape-shaped insulating material to which the curing accelerator is attached, the coil is taken out, and then the coil is heated and cured. In other words, in the process of forming the coil, a curing accelerator is applied to as few insulating parts of the coil as possible to form a sealing layer, thereby preventing the resin impregnated into the coil from leaking, and applying the curing accelerator to the tape-shaped insulator. This suppresses uneven curing speed of the impregnated resin and decrease in heat resistance due to processing.

[Embodiments of the invention]

An embodiment of the present invention illustrated in the drawings will be described below.

First, as shown in FIG. 2, a coil conductor 11 and a tape-shaped insulator 12 are wound around the outer periphery of an insulating tube 10 to form a multi-wound coil. For the coil conductor 11, for example, a rectangular insulated wire is used. For example, a glass tape is used as the tape-shaped insulator 12. No curing accelerator is attached to this tape-shaped insulator I2. And, for example, insulation made of epoxo glass @1
01 This is the beginning of winding the coil conductor 11.

It is wound sequentially along the axial direction from the beginning. On the other hand, the tape-shaped insulator 12 is also simultaneously wound around the end of the insulating tube 10 in a layered manner in the radial direction of the coil to form the upper end insulator I3a. And n
After winding 0 times, the conductor 1 has advanced to the position 11n, and the tape-shaped insulator 12 has completed the formation of the upper end insulator 13a. Next, the coil conductor 11 is sequentially wound up to n times and advances to the position Iln to form a first winding layer, and the tape-shaped insulator 12 is wound around the outer periphery of the first winding layer of the coil conductor 11. It is wound while being wrapped in the width direction, and after 0 turns, it is wound over the conductor 11n to form the first interlayer insulator 158. Next, the coil conductor 11 is connected to the winding end portion 1 of the first winding layer.
1n to the second winding layer, and sequentially winding 112 on the outer peripheral surface of the second glabellar insulator 15a from the position Z1n+I.
Proceed to position o to form the second winding layer. In the meantime, the tape-shaped insulator 12 is formed by crushing the f-end insulator 14a, and then the process moves on to forming the second r-shaped iFx rll@kneaded material 15b. Here, while forming the upper end insulator 14a, a curing accelerator that reacts with the immersion building is attached to the tape-shaped insulator 12. At the same time as the coil conductor 1zf+(zz2□) is reached, the tape-like interference 0112 also wraps around the outer circumferential surface of the conductor 11 in the second winding layer. , or the coil conductor 11 and the tape-shaped insulator 12 are turned 1? Wind it in the order of Funa IiA and close it: Perform the coil pilgrimage after winding 1i of 3. In this] process, the l'til note and the insulator 2 (the upper end of the row
Similar to the case of forming 4a, a hardening agent is applied to the tape-shaped insulator 12 only when forming the upper end insulator.

The steps of coil winding and hardening accelerator deposition are carried out, for example, by the method shown in FIG. The winding shaft 17 makes it impossible to
The tube 10 is rotated in the direction of the arrow and the coil conductor 11 and tape-like material 12 are wound up in the manner described above. Then, the tape-shaped insulating material 12 is connected to the upper end insulating material 13a and the interlayer insulating material 1.
While forming 5a, the presser roller 18 is kept raised so that the curing accelerator 2o does not adhere. Tape-shaped insulator 1
Only when the tape-shaped insulator 2 forms the upper end insulator 14a, the presser roller 18 is lowered to press down the tape-shaped insulator 12, and the curing accelerator 20 placed in the tank 19 is adhered by the adhesion roller 21.

Note that 22 in the figure is a squeeze roller. Lower the presser roller I6 only when the tape-shaped insulator 12 forms the lower end insulator of the coil.

A predetermined coil is formed while adhering the curing accelerator 2o to the tape-shaped insulator 12.

Then, when a predetermined coil winding is completed, the tape-shaped insulating material 12 is wound around the outermost portion of the coil to form an outer peripheral insulating material 16. When forming the outer peripheral insulator 16, the curing accelerator 20f is applied to the tape-shaped insulator 12 by the method described above, similarly to the case of forming the upper end insulator.

FIG. 4 is a conceptual diagram showing a cross section of the multi-wound coil formed in this manner. In the figure, 23 is a multi-turn coil, 13 is an upper end insulator formed of the tape-shaped insulator 12, and 1
4 is an upper end insulator, and 16 is an outer periphery insulator. The upper end insulator 14 and the outer periphery insulator 16 are coated with a curing accelerator and are therefore provided with hatching.

10 is an insulating cylinder.

Next, the coil 23 formed as shown in FIG. 5 is placed in a resin bath 25 in a vacuum pressure tank 24, and the coil 23 is impregnated with a defoamed resin 26 under vacuum pressure. 27 in the diagram
is the resin inlet. In this case, the temperature of the resin 26 is set to a temperature at which the curing accelerator attached to the upper end insulator I4 and the outer peripheral insulator I6 of the coil 23 easily reacts. After a certain period of time has passed, the upper end insulator 14 of the coil 23 and the outer peripheral insulator 1
The curing accelerator attached to the tape-shaped insulator 12 forming the seal 6 quickly reacts with the resin to form a sealing layer. In addition,
The inner peripheral portion of the coil 23 is provided with a non-impregnable insulating cylinder 1o, which itself serves as a sealing layer. In this way, a sealing layer is formed on the upper end insulator 14 and the outer circumferential seal 16 of the coil 23, and together with the sealing layer of the insulating cylinder 10, the coil 23
The resin impregnated inside can be prevented from leaking to the outside of the coil 23. Then, when the impregnated resin stops leaking, the coil 23 is taken out from the resin tank 25.

Finally, put the coil 23 into a drying oven and heat it.
The resin impregnated in Step 3 is cured.

A specific example of manufacturing this resin molded coil will be described. IB2MZ manufactured by Shikoku Kasei Co., Ltd. was used as a curing accelerator, and when it was attached to the tape-shaped insulator 12, it was diluted with ethyl alcohol to a 10% solution. At this time, a large amount of curing accelerator solution is attached to the tape-shaped insulator 12, so it is squeezed with a squeezing roller 22 as shown in FIG. I decided to do so. For the impregnated resin, Toshiba Chemical's αVB-2703A liquid was used as the main ingredient, and acid anhydride curing agent B-570 (manufactured by Dainippon Ink) was used as the curing agent.
The coil 23 was impregnated at a temperature of ~90°C, and after being left for 1 to 2 hours, the coil 23 was taken out from the resin bath 25 and cured by heating. As a result, the -δ temperature characteristic of the interlayer insulation part of the coil 23 shows almost the same tendency as the θ curve shown in FIG. is 20
A good resin molded coil with a KV/rus or higher was obtained.

According to this resin molded coil manufacturing method, the non-impregnated insulating cylinder 10 is used at the inner circumference of the coil 23 to prevent leakage of the impregnated resin, and the lower end and outer circumference of the coil 23 are Since the insulators 14 and 16 are coated with a curing accelerator, they quickly react with the impregnated resin and become gelled, forming a sealing layer. Therefore, it is possible to prevent resin from leaking from the coil 23 after resin impregnation. When the coil 23 is placed in a drying oven and cured by heating, the reaction between the curing accelerator and the resin occurs only at the lower end and outer periphery of the coil 23, and the interlayer insulator 15 inside the coil 23 accelerates curing. Since no agent is attached, no reaction occurs. For this reason, the curing speed of the resin within the coil 23 is partially uneven, and there is almost no peeling due to curing shrinkage or residual stress of the resin, which greatly reduces the occurrence of large PJ edge defects. Can be reduced. In addition, the insulator 14.16 to which the curing accelerator is attached remains impregnated with resin until the reaction with the resin progresses and it becomes a sealing layer.
The resin enters the inside of the coil 23 from the lower part and the outer circumference of the coil 23, thereby eliminating defects such as voids.

Furthermore, regarding the thermal problem of the coil 23,
Since the curing accelerator is not attached to the interlayer insulator 15, where the temperature inside the coil conductor 3 becomes high, this part has good temperature characteristics with good heat resistance as shown in Fig. 1 where the curing accelerator changes drastically. Since the current density of coil 2 can be increased, the current density of coil 2 can be increased.
3 can be made smaller. In addition, the coil 2 treated with a curing accelerator
3, the lower end insulator Z4 and the outer peripheral insulator 16 are interlayer insulator 1
Although the heat resistance is inferior to No. 5, the multi-wound coil of the present invention has a temperature gradient of about 20 to 50 degC between the upper and lower ends of the coil and inside and outside the coil, depending on the size of the coil. Even if the heat resistance of the outermost periphery of the coil is poor, there is no problem with the heat resistance of the device.

In addition, in the above-mentioned embodiment, as shown in FIG. 3, in order to adhere the curing accelerator to the tape-shaped insulator 12, the presser roller 18 is raised and lowered to move the insulator 12.
It is also possible to automatically control the operation of the presser roller 18 using a microcomputer. Therefore, there is no need to prepare a special process for attaching the curing accelerator to the tape-shaped insulator 12 at a stage other than coil winding, and the coil winding steps c, t, and x can be easily simplified. can.

In this embodiment, the adhesion roller 21 is used to apply the curing accelerator.
However, the tape-shaped insulator 12 may be immersed in the curing accelerator 2o in the tank 19.

The curing accelerator is not limited to liquid imitazole, but powdered curing accelerators and polymerization catalysts that react with the resin can also be used in the same manner.

can.

〔Effect of the invention〕

As explained above, according to the method of manufacturing a Jitsukiji molded coil of the present invention, by attaching a curing accelerator only to the upper end insulator and the outer circumferential insulator to form a sealing layer, the impregnated resin is A resin molded coil that can reliably prevent leakage and has excellent heat resistance and insulation properties can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the concentration of a curing accelerator treated in a tape-shaped insulator and the temperature characteristics of tan δ, and FIGS. 2 to 5 show an example of the manufacturing method of the present invention. Fig. 2 is a vertical cross-sectional view showing a multi-wound coil manufactured by the manufacturing method of the present invention, Fig. 3 is an explanatory view showing the coil winding process and the hardening accelerator adhesion process, and Fig. 4 is a coil cross section showing the sole layer. FIG. 5 is an explanatory diagram showing the resin impregnation step. 10... Insulating cylinder, II... Coil conductor, 12...
Tape-shaped insulator, Z? , Z 3 a...Top end insulator, 14, 14 a-...Top end insulator, 15
, 15a... Interlayer insulator, 16... Peripheral insulator, 1
8... Presser roller, 2o... Curing accelerator, 21...
- Adhesion roller, 22... Squeezing roller, 23. ... Coil 24 ... Vacuum pressure tank, 25 ... [Fat tank, 2
6...Resin. Applicant's agent Patent attorney Takeshi Suzue Hikoyoko 3 J'71 11 10

Claims (1)

[Claims] Tape-shaped 4 that wraps the conductor around a non-impregnable insulating cylinder and also wraps the interlayer insulation, end insulation, and peripheral edge.
The step of winding three edges to form a multi-wound coil, and the step of hardening the tape-shaped insulating material only when the tape-shaped insulating material forms the lower end insulating material and the outer circumferential material of the coil. a factory for attaching the agent; a step of impregnating the coil with resin and removing the coil when a seal is formed on the part of the tape-shaped insulation layer to which the curing accelerator is attached; and a step of heating the coil. and curing the impregnated resin.