JPS58103851A - Forming method for stator coil end of motor - Google Patents

Abstract

PURPOSE:To form a coil end by less steps by supporting dies which are formed of uniaxially oriented film in space to the coil end, which is not formed and filling thermoplastic resin in the gap between the dies. CONSTITUTION:A coil, which is not formed, is inserted into a coil inserting groove formed on the peripheral surface of a stator core 1 of a motor. In order to finish the shape of the coil end 3 of the coil 2, a die having a recess of the desired shape is prepared, the coil 2 is pressed in the recess and is shaped, and the die is then removed. The second die 4 which is formed of uniaxially oriented film is supported in slight space from the surface of the coil end 3, thermoplastic resin 5 is filled between the coil end 3 and the second die 4, and the coil end 3 is solidified. According to this method, the coil end can be formed in less steps.

Description

DETAILED DESCRIPTION OF THE INVENTION I) Technical aspects of the invention The present invention relates to a method of forming a stator coil end of an electric motor. For more details, please refer to the method for molding and solidifying the stator coil engine of a small electric motor of 20KW or less. The precision required for this is not as stringent as for the rotor, as there is no need for precise mechanical balancing. Since an electromagnetic force is applied to the coil en r section, an oscillating mechanical force having a certain relationship with the power supply frequency is applied, but this oscillating mechanical force is not a very large force 1. Soto”?
, 20=KW@degrees or less small electric motors, especially motors of several xwmf or less, use molded coils for their stator coils. There is no positive need to do so. In other words, the use of non-molded coils is sufficient to meet the technical requirements.

(3) Conventional technology and problems 1, 20 in conventional technology! For smaller model type motors, especially small induction motors, the stator coil is often a bundle of round conductors coated with a liquid insulator such as enamel or resin and dried. 0 In this case, Coil En P wraps a bundle of round conductor wires that cross the same groove with insulating thread such as glass thread, binds the east comrades of the round conductor wires with insulating thread, and then ties the entire Coil En P with insulating thread. It goes without saying that the purpose of using such non-formed coils is to reduce the number of man-hours and manufacturing costs, and in comparison with molded coils, the above objectives have been fully achieved. However, the process of binding and forming the 171 portion of the coil using the insulating threads requires the same number of man-hours as or more than that for the formed coil, leaving room for improvement.

(4) Purpose of the Invention The purpose of the present invention is to meet this demand and provide a method for molding a coil en P of a stator for a small lid electric motor using a non-formed coil with a small number of man-hours. ) Structure of the Invention The structure of the present invention is as follows: (a) a non-formed coil such as a bundle of round conducting wires with an insulated surface is inserted into a coil insertion groove provided in a stator core for an electric motor; (b) Press a concave star having the same shape as the desired coil en P into the coil end portion of the non-formed coil inserted into the above groove to transfer the 171 part of the above coil into the above shield. After molding into a concave shape, the lid is removed, and (c) a second film made of a 7-axis stretched film having the property of shrinking by curing after heating is slightly larger than this mold in any direction. The second mold is supported at a slight distance from the surface of the coil end, and a thermoplastic resin is filled between the second mold and the coil end to solidify the coil end. There is a particular thing.

The reason why the resin used in the above process is thermoplastic is that while thermosetting resins usually shrink during curing, thermoplastic resins generally do not change in volume upon curing.

Since this resin must withstand the electromagnetic force applied after curing, it must have mechanical strength, and vinyl acetate, I-lipinyl acetal, etc. are suitable as the second type of material. The reason why a 7-axis oriented film is used is that it has the property of shrinking when cured after heating. 0 Through the above steps, it is possible to mold and solidify the coil end of a small electric motor without requiring a large number of man-hours. The method for forming the stator coil P for electric motors that maintains the temperature will be explained below, and the structure and unique effects of the present invention will be clarified. , l is the stator core, 2 is the unformed coil inserted into the groove, and 3 is the coil 171 part. The unformed coil 2 is inserted into the receiving groove. The non-formed coil 2 is a bundle of round conductive wires insulated by coating and drying a liquid insulator on the p-plane.Second Step: In order to adjust the shape of the coil encircle part 3 of the above-mentioned non-formed coil 2, a desired shape is formed. A mold having a recessed part is prepared, and after the molding is performed by pressing it onto the above-mentioned coil en r part, the star is removed.

Third step: A second layer made of a uniaxially stretched 1# film that is slightly larger than the above-mentioned molding layer. l! Thermoplastic resin acetic acid 1 = -#! between the coil end portion 3 and the second Mli 4 while supporting the coil end portion 3 at a slight distance from the surface of the coil end portion 3. ! In addition to the above, it is also possible to use 4-livinyl tar as the thermoplastic resin. These thermoplastic resins do not cause volumetric shrinkage during curing and have a high mechanical strength after curing. Because it's big! be. - As mentioned above, the reason for using the axially stretched film is that once it is heated, its volume shrinks when it is partially cooled, causing the volume of the thermoplastic resin 5 to shrink.

()) As described in detail, according to the present invention, it is possible to provide a method for forming a coil enr of a small electric motor element using a non-formed coil with a small number of man-hours.

Note that, as described above, the present invention can be applied to any manufacturing method of electric motors such as induction motors, synchronous motors, and DC motors, but is particularly effective when applied to induction motors. In induction motors, the current in the stator coil is generally small and the number of turns is large, so there is a

[Brief explanation of drawings]

The figure shows a state during implementation of the third step in a method for molding a stator coil engine P for an electric motor according to an embodiment of the present invention. 1... Stator core, 2... Non-formed coil, 3...
Coil end part, 4...other type (second!I!IL
Is...Thermoplastic resin.

Claims (1)

[Claims] A non-formed coil is inserted into a coil insertion groove provided in a stator core for an electric motor, and a coil end portion of the non-formed coil inserted into the groove has a shape that is the same as the shape of Coil En P. After pressing a mold having a concave portion to form the coil end portion of the unformed coil into the concave shape of the mold, the core mold was removed, and another mold made with a 7-axis stretched film slightly larger than the first mold was used. The coil end portion of the molded non-molded coil is supported slightly apart from the surface thereof, and the gap between the other mold and the coil end portion of the molded non-molded coil is filled with thermoplastic resin. A method for molding a stator coil en P for an electric motor, comprising a step of solidifying a coil end portion of the molded non-formed coil.