JPH04322148A - Fabrication of high voltage stator coil - Google Patents

Abstract

PURPOSE:To perform fitting work easily and safely in a short time by applying a thermal shrinking film or cloth onto the linear part of slot in a coil employing a mica tape coated with hot melt adhesive and then performing thermal compression molding through a heat press. CONSTITUTION:A tape coated with a hot melt adhesive 3 is applied onto a mica tape comprising a mica 1 and a film 2. A thermal shrinking film tape 5 is then wound around the linear slot part 4a of a coil 4 formed by winding insulated strand. The linear slot part 4a is then subjected to heat press to weld the strands mutually and then it is taken out as it is(not being cooled) from a die. Thereafter, it is cooled sufficiently and the shrinked film is removed therefrom. Consequently, the coil can be fit in a core easily in a short time with high efficiency and no danger nor difficulty.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a stator coil for a high voltage rotating machine.

0002

BACKGROUND OF THE INVENTION In the manufacturing process of stator coils for high-voltage rotating machines, a wire forming process is indispensable and requires a complicated processing process and a large amount of time. For this reason, recently, as a means of simplifying the processing steps and significantly shortening the manufacturing time, a mica tape with a film backing material coated with a hot-melt adhesive on the film surface is used to attach wire conductors. An insulated structure has been proposed. Then, by winding the mica tape coated with this hot-melt adhesive, the wire bundle can be fixed together and formed into wires by heat pressing for a short time. Furthermore, various manufacturing processes such as heating, cooling, pressing, etc. after winding this type of mica tape have been proposed.

0003

However, even if short-time processing is possible using the above-mentioned hot-melt adhesive, the following problems still exist. (2) Even if the wires are heated and melted by the heat press process, the adhesive strength is weak in that state, and the wires cannot be removed from the press shape unless the wires are cooled and the adhesive solidifies. That is, after heating, it must be cooled until sufficient adhesive strength is obtained, which requires a lot of time and energy consumption. ■ If the heating process and the pressing (cold) process are separated, the workpiece must be handled in a high temperature state, making the work dangerous and difficult. ■ If the entire coil is heated, the ends of the coil will be welded and solidified, making it difficult to fit it into the core.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to provide a method for manufacturing a high voltage stator coil which is quick, safe and easy to fit.

[0005]

[Means for Solving the Problems] The structure of the present invention that achieves the above-mentioned object is to apply hot-melt adhesive to the film surface of a mica tape consisting of a film and mica in a method of manufacturing a stator coil for a high-voltage rotating machine. A tape coated with the agent is wound as wire insulation, and then a heat-shrinkable film or a heat-shrinkable woven fabric is wound around the straight slot portion of the coil around which the wire is wound. It is characterized by heat compression molding using a heat press machine.

[0006]

[Effect] The heat-shrinkable film tape shrinks during heat pressing, so even if the adhesive force is weak at high temperatures, the film wire bundle can be tightened without any problems. Heat pressing on the straight section prevents the coil end from sticking, making it easy to fit into the iron core. becomes easier.

[0007]

Embodiments Here, embodiments of the present invention will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, a mica tape made of mica 1 and a film 2 is coated with a hot melt adhesive 3 on the film surface as wire insulation. A heat-shrinkable film tape 5 is wound around the slot linear portion 4a of the coil 4 shown in FIG. 2, which is formed by winding this insulated wire and forming the coil 4, as shown in FIG. After this, the slot straight section 4
A is heat-pressed to weld the strands together, taken out from the mold as is (without cooling), and after cooling sufficiently, the shrink film 5 is removed.

(Specific Example 1) Mica tape (Samaica Film (R)) (trade name) for wire insulation is made by coating a rectangular copper wire with a wire size of 6.5 x 3.0 with a hot melt type adhesive. ) manufactured by Isola Co., Ltd.) with two layers of half-wrap tape. A bundle of 6 wire conductors with this wire insulation, 2
A sea cucumber-shaped coil with a total length of 2000 mm before being formed into a tortoise-shell shape was formed by winding the coil 4 turns in a row. Thereafter, a heat-shrinkable polyester tape was taped once on the 1200 mm linear portion of the slot with a 1/2 wrap, and the linear portion of the slot was set in a heat press machine preheated to about 150° C. to perform heat pressing and hold for about 10 minutes. Thereafter, the coil was immediately taken out, and when the coil returned to room temperature, the heat-shrinkable polyester film tape was removed.

(Comparative Example 1) Instead of the heat-shrinkable polyester film tape mentioned in the above specific example, a normal polyester film tape was used, and after heat pressing was performed for 10 minutes in the same manner, the heater power was cut off. The coils were taken out after varying the standing time, and the polyester tape was removed when the coil temperature returned to room temperature.

(Comparative Example 2) In the process of the above specific example, instead of using a heat press, the coil was heated in an oven at 150°C for 30 minutes and then immediately taken out. After the temperature of the coil returned to room temperature, a heat-shrinkable polyester film tape was attached. Removed.

[0011] The results of forming wire coils in the above-mentioned specific examples and comparative examples were as shown in Table 1.

0012

[Table 1]

[0013] In the case of the specific example, both adhesion and dimensional accuracy were good even when the sample was taken out immediately after heat pressing at 150°C for 10 minutes. In addition, there was almost no sticking of the coil end portion, and it maintained sufficient flexibility to be attached to the iron core.

[0014] In the case of Comparative Example 1, if the temperature of the coil is 125°C or higher when the coil is taken out within 0 to 10 minutes after the heater is cut after heat pressing at 150°C for 10 minutes, the adhesion between the wires is insufficient. The wires were falling apart. If the temperature of the coil taken out after about 30 minutes is 95°C, there may be some areas with poor adhesion, and the dimensional accuracy may be affected.
There is a large variation. Leave it for about 60 minutes until the coil temperature reaches 7.
In the case of 0°C, satisfactory results were obtained in both adhesiveness and dimensional accuracy.

[0015] In the case of Comparative Example 2, after being heated in an oven at 150°C for about 30 minutes, it was immediately taken out and the adhesive strength was good, but there was a large variation in dimensional accuracy.
In particular, it was found that the dimension in the height direction of the coil increased, making it impractical. It was also found that the coil ends were also stuck and had no flexibility, making it difficult to fit them into the iron core.

In the above embodiments, a heat-shrinkable film was described, but the present invention can also be applied to a heat-shrinkable woven fabric.

[0017]

As explained above, according to the present invention, the following effects can be obtained by applying heat shrinkable material to the slot straight portion and performing heat pressing. ■ Since the coil wire bundle is tightened to prevent it from moving during heat pressing, there is no need for cooling and it can be taken out immediately, reducing time and increasing production efficiency. ■ Eliminates the need for heat press type cooling, eliminating wasted energy. ■ Heat presses do not separate the heating process and the pressing process, so the work is not dangerous or difficult, unlike conventional methods. ■ Since the slot straight section is heat press molded, dimensional accuracy can be improved, and the coil end part does not stick, making it easy to fit into the core. ■ Since it contracts in the pressed state, the strands do not shift. ■ The heat-shrinkable film can be removed in a sufficiently cooled state, resulting in high adhesive strength and good dimensional accuracy.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a film made of mica tape coated with a hot melt adhesive.

FIG. 2 is a configuration diagram of a sea cucumber-shaped coil.

FIG. 3 is a view taken along the line A-A' in FIG. 2;

[Explanation of symbols]

1 Mica 2 Film 4 Coil 4a　Slot straight part 5 Heat shrink polyester tape

Claims (1)

[Claims] Claim 1: In a method for manufacturing a stator coil for a high-voltage rotating machine, a mica tape consisting of a film and mica is wound with a tape coated with a hot melt adhesive on the film surface as wire insulation, and then this A high voltage method characterized in that a heat-shrinkable film or a heat-shrinkable woven fabric is wound around the slotted linear portion of a coil in which a wire is wound, and then the slotted linear portion is heated and compression-molded using a heat press machine. Method of manufacturing stator coils.