JP5738705B2 - Stator manufacturing method - Google Patents

Description

  The present invention relates to a stator manufacturing method in which a coil is assembled to a stator core.

  Conventionally, as this type of technology, for example, a “stator winding fixing method” described in Patent Document 1 below is known. In this fixing method, a stator winding (coil) is inserted inside the stator core (stator core). Next, the stator core into which the coil is inserted is immersed in a varnish tank, and the coil is impregnated with the varnish. Next, a shape-retaining mandrel is inserted inside the coil. Thereafter, the varnish is heated and cured while the stator core, the coil, and the mandrel are integrated. Thereafter, the mandrel is removed to complete the stator.

  On the other hand, Patent Document 2 described below describes a stator in which a stator core has a plurality of slots, and a rectangular wire is used for a coil assembled in the slots.

JP 2001-069732 A JP 2010-259266 A

  However, in the fixing method described in Patent Document 1, since the mandrel is removed after the varnish is thermally cured, the varnish may adhere to the removed mandrel. For this reason, the process of removing the varnish adhering from a mandrel was needed.

  On the other hand, in the stator described in Patent Document 2, the coil position on the inner peripheral side where the eddy current loss is large is important in order to reduce the loss and heat. However, with the increase in the space factor of the coil, the coil in the coil end or the slot is likely to jump out to the inner peripheral side of the stator core due to the spring back of the coil itself. Therefore, in order to impregnate the coil with varnish, it is necessary to restrain the inner peripheral side of the coil with a jig before that. In addition, this jig is used many times for manufacturing other stators. For this reason, a varnish adheres to a jig | tool, the process of removing a varnish from a jig | tool is needed, and there existed a problem in the point of productivity.

  The present invention has been made in view of the above circumstances, and its purpose is to constrain the inner peripheral side of the coil with a jig and to remove the varnish from the jig even if the coil is fixed with the varnish. It is an object of the present invention to provide a method for manufacturing a stator that can eliminate the above.

In order to achieve the above object, the invention described in claim 1 is a method for manufacturing a stator in which a coil is assembled to a stator core, and a non-crystallized resin film is previously formed on the surface of a coil wire constituting the coil. After the coil having the resin film formed is assembled to the stator core, a jig for holding the shape of the coil is mounted on the inner peripheral side of the stator core, and then the heating temperature is applied to the stator core and the coil by the coil wire. The heat treatment is performed at a temperature equal to or higher than the low-temperature annealing temperature of the resin and the temperature for crystallizing the resin film, and after removing the jig, the coil is varnished to cure the coil shape. After the coil wire and the uncrystallized resin film are heated while being held by the tool, the coil is varnished so that the varnish does not adhere to the jig. The the spirit of the invention.

According to the configuration of the invention, since the stator core and the coil are heat-treated in a state where the shape of the coil on which the resin film is formed is held by the jig, And the non-crystallized resin film is heated. Thereafter, since the varnish treatment is performed on the coil after the jig is removed, the varnish does not adhere to the jig. Further, the coil is cured by low temperature annealing by heat treatment in the shape held by the jig. Further, the resin film of the coil is crystallized and cured by heat treatment in the shape held by the jig.

According to the first aspect of the present invention, even if the inner peripheral side of the coil is restrained by the jig and the coil is fixed with the varnish, the step of removing the varnish from the jig can be omitted. The productivity of the stator can be improved by that amount. In addition, as a result of using the jig, the spring back of the coil in the slot can be relaxed before the coil is fixed with the varnish, and between the tip on the inner peripheral side of the coil and the tip of the tooth. Necessary gaps can be secured. Further, the spring back of the coil in the slot can be further relaxed.

The longitudinal cross-sectional view which shows the stator concerning 1st Embodiment and was manufactured. The AA sectional view taken on the line of FIG. 1 which shows the stator concerning the embodiment. The flowchart which shows the content of the manufacturing method of a stator according to the embodiment. Sectional drawing which shows the coil wire which concerns on the same embodiment and formed the resin film. The top view which concerns on the same embodiment and shows a stator core. The cross-sectional view which shows the state which concerns on the embodiment and the coil was assembled | attached to the stator core. Sectional drawing which shows the stator in the middle of manufacture with which the jig | tool was mounted | worn in the same embodiment. The top view which concerns on the embodiment and shows the relationship between the slot of one core piece, and a jig | tool. The graph which shows the annealing characteristic of the oxygen-free copper which comprises a coil wire according to the same embodiment. The graph which shows the density change characteristic of "PPS" which concerns on the embodiment and comprises a resin film. The top view which concerns on the same embodiment and shows the relationship between the slot of one core piece, and a coil. The graph which compares and shows the magnitude | size of the clearance gap between the inner peripheral side front-end | tip of a coil, and the front-end | tip of teeth according to the same embodiment by the difference with and without heat processing. The longitudinal cross-sectional view which concerns on 2nd Embodiment and shows the stator in the middle of manufacture. The longitudinal cross-sectional view which concerns on 3rd Embodiment and shows the stator in the middle of manufacture. The cross-sectional view which shows the stator in the middle of manufacture according to the same embodiment. The top view which concerns on the same embodiment and shows a jig | tool.

<First Embodiment>
Hereinafter, a first embodiment of a method for manufacturing a stator according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a longitudinal sectional view of the manufactured stator 1. FIG. 2 shows the stator 1 manufactured in the same manner as a cross-sectional view taken along the line AA of FIG. 1 (in FIG. 2, the coil 3 is not hatched for convenience). As shown in FIGS. 1 and 2, the stator 1 is used for a motor, and includes a stator core 2, a coil 3 assembled to the stator core 2, and an outer ring 4 attached to the outer periphery of the stator core 2. Prepare.

  As shown in FIGS. 1 and 2, the stator core 2 includes an annular yoke 11 and a plurality of teeth 12 disposed inside the yoke 11 and projecting toward the center and disposed at equal angular intervals. Including. A slot 13 that is a gap is formed between adjacent teeth 12. The coil 3 is inserted into these slots 13 and assembled. The stator core 2 is formed by integrating a plurality of core pieces 5 in an annular shape and caulking the outer periphery with an outer peripheral ring 4.

  Next, a method for manufacturing the stator 1 will be described. FIG. 3 is a flowchart showing the contents of this manufacturing method.

  First, in (1) of FIG. 3, as shown in a sectional view in FIG. 4, a resin film 6 is formed on a coil wire 3a constituting the coil 3 for the purpose of insulation. In this embodiment, the coil wire 3a is configured by a flat wire made of copper (oxygen-free copper). The resin film 6 is made of thermoplastic polyphenylene sulfide (PPS).

  Next, in (2) of FIG. 3, the coil 3 in which the resin film 6 is formed is assembled to the stator core 2 shown in a plan view in FIG. As a result, a state in which the coil 3 is assembled to the stator core 2 as shown in the plan view of FIG. 6 is obtained. As shown in FIG. 6, the coil 3 is assembled in each slot 13 of the stator core 2 (in FIG. 6, for convenience, the coil 3 is not hatched). Although not shown in FIG. 6, the outer ring 4 described above is attached to the outer periphery of the stator core 2.

  Next, in (3) of FIG. 3, a pair of upper and lower ring-shaped jigs 7 are attached to the coil 3 on the inner peripheral side of the stator core 2 as shown in a cross-sectional view in FIG. 7. These jigs 7 are mounted inside the upper and lower coil ends 3u and 3d, respectively. FIG. 8 is a plan view showing the relationship of the jig 7 with respect to the slot 13 of one core piece 5. As shown in FIG. 8, by mounting the jig 7 on the inner peripheral side of the coil 3, the coil 3 is pressed and held in the outer peripheral direction.

  Next, in (4) of FIG. 3, as shown in FIG. 7, the integrated body of the stator core 2, the coil 3, the outer peripheral ring 4, and the jig 7 is heat-treated. In this embodiment, the integrated object is heated by passing it through a hot stove. In this embodiment, the temperature of the heat treatment is set to a temperature equal to or higher than the low-temperature annealing temperature of the coil wire 3 a and a temperature for crystallizing the resin film 6. As this temperature, for example, “200 ° C. to 240 ° C.” can be applied. More specifically, heating is performed at a heating temperature of “240 ° C.” for “30 minutes”.

  FIG. 9 is a graph showing the annealing characteristics of oxygen-free copper constituting the coil wire 3a. This graph shows changes in various characteristics of oxygen-free copper with respect to temperature changes, namely, “tensile strength”, “proof strength”, “hardness”, and “elongation”. As is apparent from this graph, it can be seen that the various characteristics of oxygen-free copper begin to change abruptly from “200 ° C.” and change gradually at “250 ° C.”. The upper limit value of the set temperature is set to “240 ° C.” in consideration of the melting point of the resin film 6.

  FIG. 10 is a graph showing density change characteristics of “PPS” constituting the resin film 6. This graph shows the change in the density of PPS with respect to the heating time according to the difference of the heating temperatures “180 ° C., 190 ° C., 200 ° C., 210 ° C., 220 ° C.”. As is apparent from this graph, it is understood that the density approaches the upper limit value in about 3 minutes by heating PPS at each temperature of “180 ° C. to 220 ° C.”. That is, PPS becomes dense and hard by heating at a temperature of “180 ° C. to 220 ° C.” for 3 minutes or more.

  In this embodiment, the temperature of the heat treatment is set to “200 ° C. to 240 ° C.” based on the result of the above graph and the melting point of PPS.

  Next, at (5) in FIG. 3, the jig 7 is removed from the coil 3 as shown in a plan view in FIG. 11. FIG. 11 shows the relationship of the coil 3 with respect to the slot 13 of one core piece 5. In this state, the coil wire 3a is annealed by the heat treatment, and the resin film 6 is hardened. Therefore, the coil 3 in the slot 13 can hold the shape pressed by the jig 7. Thereby, the spring back of the coil 3 in the slot 13 can be relieved. As a result, as shown in FIG. 11, a necessary gap g <b> 1 can be ensured between the tip on the inner peripheral side of the coil 3 and the tip of the tooth 12.

  FIG. 12 is a graph showing the size of the gap g1 between the tip on the inner peripheral side of the coil 3 and the tip of the tooth 12 in comparison with the difference in the presence or absence of the heat treatment in (4) of FIG. This graph shows the difference between the average values M1 and M2 of the gap g1 with respect to “without heating” and “with heating”. In the graph, “L1” indicates a necessary lower limit value of the gap g1, and “L2” indicates a necessary standard value of the gap g1. As is apparent from this graph, the average value M1 of the gap g1 may be lower than the lower limit L1 without heating, whereas the average value M2 of the gap g1 exceeds the standard value L2 with heating. . Therefore, in this embodiment, it can be seen that the necessary gap g1 can be secured by the heat treatment of (4) in FIG.

  Thereafter, in (6) of FIG. 3, the coil 3 is varnished with the jig 7 removed. In this embodiment, the coil 3 is impregnated with varnish, and the varnish is cured by heat.

  Through the above steps, the stator 1 as shown in FIGS. 1 and 2 can be obtained.

  According to the manufacturing method of the stator in this embodiment described above, the stator core 2 and the coil 3 are subjected to heat treatment in a state where the shape of the coil 3 on which the resin film 6 is formed is held by the jig 7. Accordingly, the coil 3 and the resin film 6 in an uncrystallized state (half-life state) are heated while the shape of the coil 3 is held by the jig 7. Thereafter, since the varnish treatment is performed on the coil 3 after the jig 7 is removed, the varnish does not adhere to the jig 7. For this reason, even if it restrains the inner peripheral side of the coil 3 using the jig | tool 7 and fixes the coil 3 with a varnish, the process of removing a varnish from the jig | tool 7 can be skipped. As a result, the productivity of the stator 1 can be improved, and the jig 7 can be reused without removing the varnish from the jig 7.

  Further, in this embodiment, the coil 3 is annealed at a low temperature by heat treatment in a state where the shape is held by the jig 7, and the stress is removed and the coil 3 is cured. For this reason, as a result of using the jig 7, the spring back of the coil 3 in the slot 13 can be relaxed before the coil 3 is fixed with the varnish. As a result, a necessary gap g <b> 1 can be secured between the inner peripheral side tip of the coil 3 and the tip of the tooth 12.

  In this embodiment, the resin film 6 of the coil 3 is crystallized and cured by heat treatment while the shape is held by the jig 7. For this reason, the spring back of the coil 3 in the slot 13 can be further relaxed.

Second Embodiment
Next, a second embodiment embodying the stator manufacturing method of the present invention will be described in detail with reference to the drawings.

  In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, description thereof is omitted, and different points are mainly described.

  FIG. 13 is a longitudinal sectional view of the stator 1 being manufactured. FIG. 13 shows another method for the heat treatment of (4) of FIG. In the first embodiment, a hot stove is used as a heat treatment method, but in this embodiment, the inner core IH coil 21 and the outer diameter IH coil 22 are energized by the power source 23, respectively, so that the stator core 2, the coil 3, etc. Induction heating.

  Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained with respect to the stator manufacturing method.

<Third Embodiment>
Next, a third embodiment of the stator manufacturing method according to the present invention will be described in detail with reference to the drawings.

  FIG. 14 is a longitudinal sectional view of the stator 1 being manufactured. FIG. 15 shows the stator 1 that is still being manufactured by a cross-sectional view taken along line B-B in FIG. 14 (in FIG. 15, the coil 3 is not hatched for convenience). This embodiment is different from the first and second embodiments in terms of the jig 8. FIG. 16 is a plan view showing the jig 8 of this embodiment. As shown in FIG. 16, the jig 8 has a substantially cylindrical shape, and a plurality of ribs 8a extending in the axial direction are formed at equal angular intervals on the outer periphery thereof. The outer diameter of the jig 8 is set to be substantially the same as the inner diameter of the stator core 2. The width of each rib 8 a is set to be approximately the same as the width of each slot 13 of the stator core 2. The arrangement of the plurality of ribs 8 a is set to be the same as the arrangement of the plurality of slots 13. 14 and 15, the jig 8 is mounted on the inner peripheral side of the stator core 2, and the ribs 8a are inserted into the slots 13, thereby pressing the coil 3 in the slot 13 in the outer peripheral direction. To hold.

  Therefore, also in this embodiment, the same effect as that of the first embodiment can be obtained with respect to the stator manufacturing method.

  The present invention is not limited to the above-described embodiments, and a part of the configuration can be changed as appropriate without departing from the spirit of the invention.

  For example, in the second embodiment, induction heating is adopted as a method for heat treatment of the coil 3, but the coil may be directly heated by energization heating.

  In each of the above embodiments, copper (oxygen-free copper) is used as the material of the coil wire 3a, but aluminum can also be used as the material of the coil wire.

  Furthermore, in each said embodiment, although the coil wire 3a was comprised by the flat wire, not only a flat wire but a round wire can also be used.

  The present invention can be used for manufacturing a stator used in a motor.

1 Stator 2 Stator Core 3 Coil 3a Coil Wire 6 Resin Film 7 Jig 8 Jig

Claims (1)

A stator manufacturing method in which a coil is assembled to a stator core,
A resin film in an uncrystallized state is formed in advance on the surface of the coil wire constituting the coil, and after assembling the coil with the resin film formed on the stator core, on the inner peripheral side of the stator core A jig for holding the shape of the coil is mounted, and then the stator core and the coil are heated at a temperature higher than the low-temperature annealing temperature of the coil wire and higher than the temperature for crystallizing the resin film. After the heat treatment is performed and then the jig is removed, the coil is varnished so that the shape of the coil is held by the jig and the coil wire is in an uncrystallized state. Since the varnish treatment is performed on the coil after the resin film is heated, the varnish does not adhere to the jig .

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