JP2012228087A - Winding wire, coil formation method, and coil breakage repairing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a winding wire capable of easily and promptly repairing a crack when the crack occurs on an insulation coating of the winding wire at the time of forming a coil made of a winding wire around teeth, to provide a formation method of a coil using the winding wire, and to provide a coil breakage repairing method capable of repairing a crack when the crack occurs on the insulation coating constituting the winding wire after installing a motor with the coil.SOLUTION: Winding wires 1A and 1B consist of a conductor 1a, and an insulation coating 1d formed around the conductor 1a. The insulation coating 1d consists of an inner coating 1b arranged on a conductor side, and an outer coating 1c arranged around the inner coating 1b; the outer coating 1c consists of a thermoplastic resin; and the inner coating 1b consists of a thermoplastic resin and a material including therein a foaming agent B' with a foaming temperature higher than the softening point of the thermoplastic resin.

Description

  The present invention relates to, for example, a winding used for a motor coil and a method of forming a coil using the winding, and further, when a crack occurs in an insulating film constituting the winding after the motor equipped with the coil is used. The present invention relates to a method for repairing a damaged coil.

  The stator constituting the motor is formed of a stator core formed by laminating an annular yoke, a plurality of teeth projecting radially inward from the yoke, and a steel plate having a slot formed between adjacent teeth. For example, a stator is manufactured by inserting a three-phase coil into a unique slot. The coil winding has an insulating coating such as an enamel coating around the conducting wire to insulate the conducting wire in the coil, and an insulator such as an insulating bobbin or slot insulation paper between the tooth and the coil. Is provided for insulation between the core and the coil. Further, in the case of a three-phase AC coil, for example, as disclosed in Patent Document 1, interphase insulation between different phase coils is achieved by an insulator such as interphase insulating paper. The coil forming winding described above is prepared by, for example, dissolving a thermosetting enamel resin around a copper conductive wire in a solvent and applying it to a thickness of several μm. The winding is manufactured by forming an enamel film having a desired thickness by repeating a plurality of times.

  In addition to the form in which the conductive wire is protected by an insulating coating made of one layer of enamel, a polyester layer is disposed around the conductive wire, a polyester imide layer is further disposed around the polyester layer, and a self-lubricating polyamide layer is disposed around the polyester layer. A winding having a multi-layered enamel film formed by arranging a multi-layer structure is disclosed in Patent Document 1, and there are many other techniques related to a winding having such a multi-layered insulating film.

  By the way, motors mounted on modern vehicles such as hybrid vehicles and electric vehicles have been reduced in size and weight, and the coil winding form has become complicated as the motors have been reduced in size. Yes. For example, a rectangular wire is used to increase the space factor of the coil, but at the coil end, measures are taken to minimize the protrusion length from the coil end by twisting the rectangular wire. As a result, the coil shape and winding form are complicated.

  Especially when a coil is formed using a flat wire, stress concentration occurs due to an external force twisted at the corner portion of the flat wire, etc., when twisting it into a complicated shape as described above, As a result, cracks are likely to occur in the enamel film, leading to a decrease in insulation.

  And the fact that cracks are likely to occur in the enamel coating as described above is the same as whether the enamel coating has a single layer structure or a multilayer structure disclosed in Patent Document 1. Similarly, when lines are applied, the occurrence of cracks is remarkable due to the stress concentration described above.

JP 2005-78883 A

  The present invention has been made in view of the above-described problems. When a coil made of a winding is formed around a tooth, when a crack occurs in the insulating film of the winding, or the coil is arranged around the tooth. When a crack occurs in the insulation film of the winding after the motor is used, this winding can be repaired easily and quickly, a method of forming a coil using this winding, and this It is an object of the present invention to provide a method for repairing a damaged coil, which repairs a crack when an insulating film constituting a winding is cracked after a motor including the coil is used.

  In order to achieve the above object, a winding according to the present invention comprises a conductive wire and an insulating coating formed around the conductive wire, and the insulating coating comprises an inner coating disposed on the conductive wire side and an outer coating disposed around the inner coating. The outer coating is made of a thermosetting resin, and the inner coating is made of a thermoplastic resin and a material containing therein a foaming agent having a foaming temperature higher than the softening point of the thermoplastic resin. .

  The winding of the present invention has a two-layer insulating coating around the conductor, and the inner coating on the conductor side is a thermoplastic resin and a foaming agent having a foaming temperature higher than the softening point of the thermoplastic resin inside the thermoplastic resin The outer outer coating is formed of a thermosetting resin. First, when forming a film by dipping or coating a thermoplastic resin that forms an inner coating around the conductor and baking it, the foaming temperature of the foaming agent is higher than the softening point (or melting point) of the thermoplastic resin. Since it is high, the foaming agent does not foam during this film formation.

  After forming an inner coating around the conductor, an outer coating made of a thermosetting resin is formed around the inner coating. Since the outer coating is made of a thermosetting resin, the thermosetting resin is cured at least at a temperature lower than the foaming temperature of the foaming agent. Foaming can be suppressed.

  In this way, the inner coating is formed from a thermoplastic resin, a foaming agent having a foaming temperature higher than the softening point of the thermoplastic resin is dispersed therein, and the outer coating is made of a thermosetting resin. By forming an insulating coating with a two-layer structure with an outer coating, a two-layer insulating coating is formed around the conductor without foaming the foaming agent contained in the inner coating when forming the insulating coating. It becomes possible to do.

  And this coil | winding is formed in the surroundings of a tooth (The thing by which the coil | winding was wound beforehand may be arrange | positioned in a tooth | gear, and the method of winding a coil | winding around a teeth may be sufficient.) For example, a three-dimensional deformation process is performed in which, for example, the coil end is twisted to be pushed toward the yoke side and the coil end protruding length is made as low as possible.

  Here, it is preferable to apply a rectangular wire made of copper material in order to increase the space factor in the slot, in addition to a conventional circular wire having a circular cross section or a copper material having an elliptical cross section.

  The thermoplastic resin that forms the inner coating includes polyimide (PI), polyamideimide (PAI), polyetheretherketone (PEEK), polyphenylsulfone (PPSU), polyetherimide (PEI), and polyethersulfone. Any one of Hong (PESU), polysulfone (PSU), liquid crystal polymer (LCP), polyphenylene sulfide (PPS), polyphthalamide (PPA), polyamide (PA) and the like can be applied. Further, as the foaming agent contained in the thermoplastic resin of the inner coating, a bistetrazole-based foaming agent can be applied, and more specifically, bistetrazole diammonium, bistetrazole piperazine and the like can be mentioned. Furthermore, as the thermosetting resin that forms the outer coating, any one of thermosetting polyamideimide, polyesterimide, epoxy resin, and phenol resin can be applied.

  In particular, when a three-dimensionally complicated deformation process as described above is performed on a coil formed by applying this rectangular wire, cracks are likely to occur in the insulating film constituting the winding.

  Therefore, when a crack occurs in the insulating coating that forms the winding when processing a coil having such a complicated shape, the crack is repaired easily and quickly by applying the winding of the present invention. It is possible to form a coil with guaranteed properties.

  That is, the present invention extends to a method for forming such a coil. The coil forming method includes a first step of winding the winding around the teeth of the stator, and an insulating coating in the first step. When a crack is generated, the heat treatment is performed at a temperature equal to or higher than the foaming temperature of the foaming agent to soften the inner film, and the crack is closed with the inner film softened by foaming of the foaming agent.

  Heat treatment at a temperature higher than the foaming temperature of the foaming agent is applied to the cracked portion generated in the insulating coating when the coil is processed, so that the thermoplastic resin of the inner coating is softened (or melted), and the foaming agent in the inner coating is softened (melted). Foams to form voids (bubbles), and the softened inner coating expands by the voids and expands outward, and the softened inner coating closes the cracks formed from the inner coating to the outer coating. Can do.

  As described above, when a winding such as a rectangular wire is arranged around the teeth and the coil end is twisted, for example, when three-dimensionally complicated deformation processing is performed, cracks are formed in the insulating film constituting the winding. If it occurs, the crack portion is heat-treated as desired to fill the crack with a thermoplastic resin constituting the inner coating, repair the insulating coating, and complete the coil formation.

  Furthermore, the present invention extends to a method for repairing a damaged coil, which is repaired when a crack is generated in an insulating film constituting a winding after the use of a motor equipped with this coil. When a coil having a coil formed by winding a coil around a stator tooth is cracked, the coil is heat-treated at a temperature higher than the foaming temperature of the foaming agent to soften the inner film. The crack is closed by the inner film softened by foaming of the foaming agent.

  This repair method is also the same as the coil formation method already described. When a crack occurs in the insulation film of the winding after the motor is used, the crack is blocked by the softened inner film by heat-treating the crack in the insulation film. Then, the crack breakage portion is repaired.

  When applying this method for repairing damage to a coil, it is possible to repair the damage to an insulating coating portion where no crack has occurred during coil formation. In the insulating coating where cracks occurred during coil formation, the foaming agent was foamed by heat treatment at that time. It is because it cannot be made to foam.

  Similar to the method for forming a coil of the present invention, even when a crack occurs in an insulating film constituting a winding after the motor is used, a crack is generated without replacing the coil in order to guarantee the insulation. The damaged portion of the coil can be quickly repaired with simple and inexpensive maintenance by simply heat-treating the portion, and the insulation of the coil can be ensured.

  As can be understood from the above description, the winding of the present invention, a method of forming a coil using the winding, and a method for repairing a damaged coil after use of a motor including the coil using the winding According to the present invention, the winding has a two-layer insulating coating around the conductor, and the inner coating on the conductor side contains a thermoplastic resin and a foaming agent having a foaming temperature higher than the softening point of the thermoplastic resin therein. The outer outer coating is formed from a thermosetting resin, so that the foaming agent is not foamed during film formation of the inner coating and the outer coating, after coil processing or motor use. When a crack occurs in the insulation coating that forms the winding, the thermoplastic resin in the inner coating is softened by heat treatment at a temperature equal to or higher than the foaming temperature of the foaming agent, and the foaming agent in the interior foams to form voids. The softened inner coating Therefore, it expands to the outside by volume expansion, and the crack formed from the inner coating to the outer coating is closed by the softened inner coating, thereby repairing the damaged part due to the crack and ensuring the insulation of the winding. it can.

It is the perspective view explaining the state by which the coil end in a stator core was twisted and deform | transformed and was extruded to the yoke side. It is the II-II arrow line view of FIG. 1, Comprising: It is a longitudinal cross-sectional view of the coil | winding which forms a coil. (A) is the longitudinal cross-sectional view explaining the state which the crack generate | occur | produced in the insulating film which comprises a coil | winding at the time of coil processing, (b) is the inner film which softened the generated crack obstruct | occluded and an insulating film is restored. It is a longitudinal cross-sectional view which shows the state.

  Embodiments of a method for forming a winding and a coil according to the present invention will be described below with reference to the drawings. In addition, although the winding of the example of illustration is what consists of a flat wire, of course, the coil | winding of this invention includes what consists of a general conducting wire of circular cross-section or an ellipse other than a flat wire. is there.

(Winding)
FIG. 1 is a perspective view illustrating a state in which a coil end in a stator core is twisted and deformed and pushed toward the yoke side, and FIG. 2 is a view taken along the line II-II in FIG. It is a longitudinal cross-sectional view of a coil | winding.

  FIG. 1 shows only a portion where a U-phase and a V-phase of a different-phase coil are in contact with each other at a coil end among three-phase AC motor coils. Therefore, in other parts, there are places where the U phase and the W phase are in contact at the coil end, and places where the V phase and the W phase are in contact at the coil end. In addition, a plurality of in-phase windings 1A,..., 1B,... Are inserted into one slot 2c defined by the teeth 2a, 2a constituting the stator core 2, and this is separately provided beyond the plurality of teeth. A coil of each phase is formed in the stator core 2 by being inserted into the slot and making a round around the annular stator core 2. Note that interphase insulating paper (not shown) is disposed between the phases of the U-phase coil and the W-phase coil, and an insulator such as slot insulating paper (not illustrated) is disposed between the coil of each phase and the slot surface. .

  As is apparent from FIG. 1, the coil ends of both the U-phase coil and the V-phase coil are twisted and deformed three-dimensionally, and are pushed out to the yoke 2b side so that the protruding length of the coil end is as short as possible. It is processed to become.

  The windings 1A and 1B constituting the U-phase coil and the V-phase coil are both made up of a flat conducting wire 1a and an insulating coating 1d. The insulating coating 1d is made of a thermoplastic resin disposed on the flat conducting wire 1a side. And an outer coating 1c made of a thermosetting resin disposed around the inner coating 1b.

  Here, as the thermoplastic resin forming the inner coating 1b, polyimide (PI), polyamide imide (PAI), polyether ether ketone (PEEK), polyphenyl sulfone (PPSU), polyether imide (PEI), poly Any one of ether sulfone (PESU), polysulfone (PSU), liquid crystal polymer (LCP), polyphenylene sulfide (PPS), polyphthalamide (PPA), polyamide (PA), and the like can be applied.

  Furthermore, a foaming agent B ′ is contained in the inner coating 1b, and a bistetrazole-based foaming agent can be applied as the foaming agent B ′. More specifically, bistetrazole diammonium, bistetrazole piperazine and the like can be used. Can be mentioned.

  As the outer coating 1c, any one of thermosetting polyamide imide, polyester imide, epoxy resin, and phenol resin can be applied.

  As described above, various materials can be applied to the thermoplastic resin of the inner coating 1b, the foaming agent B ′, and the thermosetting resin of the outer coating 1c. Here, the foaming temperature of the foaming agent B ′ is set to the inner coating 1b. The materials of both the thermoplastic resin and the foaming agent are selected so as to be higher than the softening point (or melting point) of the thermoplastic resin. For example, a polyether ether ketone (PEEK) having a softening point of about 350 ° C. as the thermoplastic resin of the inner coating 1b, and a bistetrazole type having a foaming temperature of about 360 ° C. and a higher foaming temperature than PEEK as the foaming agent B ′. A blowing agent should be applied.

  In this way, the inner coating 1b is formed from a material in which a foaming agent having a foaming temperature higher than the softening point of the thermoplastic resin that is the matrix resin is contained in the thermoplastic resin, and thermosetting around this film. When the outer coating 1c made of resin is formed, when the insulating coating 1d made of the inner coating 1b and the outer coating 1c is formed around the conductor 1a by coating or baking, it is contained in the inner coating 1b. The foaming agent B ′ is prevented from foaming during the film formation process.

(Coil forming method)
Next, a method for forming a coil will be outlined with reference to FIG. 3a is a longitudinal sectional view illustrating a state in which a crack is generated in the insulating film constituting the winding during coil processing, and FIG. 3b is a diagram illustrating the repair of the insulating film by closing the inner film that softens the generated crack. It is a longitudinal cross-sectional view which shows the state. 3A and 3B, the winding 1A is taken up and explained, but this explanation is also applicable to the winding 1B and a winding for a W-phase coil (not shown). Here, the “coil forming method” means that the coil is processed while being three-dimensionally deformed as shown in FIG. 1, and that the insulating film of the winding constituting the coil is cracked during this processing. This includes repairing the crack and ensuring the insulation of the coil when it occurs.

  The coil is formed by using a winding having a cross-sectional structure as shown in FIG. 2 and arranging a U-phase coil, a V-phase coil and a W-phase coil in each slot 2c constituting the stator core 2. A coil of each phase is wound around the teeth 2a to be performed (first step).

  Here, as shown in FIG. 1, particularly at the coil end, an external force is applied and twisted, and the projection is pushed to the yoke 2 b side while being deformed three-dimensionally to shorten the protruding length at the coil end. .

  For example, during such processing, as shown in FIG. 3a, cracks C are likely to occur in various portions of the insulating coating 1d of the winding 1A.

  When it is confirmed that the crack C is generated in the insulating coating 1d in this way, as shown in FIG. 3b, the location where the crack C is generated is detected by the foaming agent B ′ contained in the inner coating 1b using a heater H or the like. Heat treatment is performed at a temperature equal to or higher than the foaming temperature (second step).

  By this heat treatment, the thermoplastic resin of the inner coating 1b is softened (or melted), and the foaming agent B ′ inside thereof is foamed to form voids B, and the inner coating 1b softened by the voids B undergoes volume expansion. The softened inner coating 1b ′ closes the crack C that swells outward and extends from the inner coating 1b to the outer coating 1c.

  That is, by this heat treatment, the crack C is completely closed by the thermoplastic resin and the gap B inside thereof, the damage of the insulating coating 1d is repaired, and the wound winding 1A ′ (after repair) in which the insulation property of the flat wire 1a is guaranteed. Coil 1A ′) is formed.

  This coil forming method can also be applied when repairing a crack C generated in the insulating coating 1d constituting the windings 1A, 1B and the like after the use of a motor equipped with this coil. That is, when a crack is generated in the motor after the use of the motor including the coils 1A, 1B, etc., in which the windings 1A, 1B are wound around the teeth 2a of the stator core 2, the foaming agent B ′ is foamed. Above the temperature, cracks such as the coils 1A and 1B are heat treated to soften the inner coating 1b, and the void B is formed by foaming of the foaming agent B ′. The inner coating 1b softened by the void B expands in volume. The crack C bulges outside and closes the crack C.

  In this way, when a crack occurs in the insulating film that constitutes the winding after the motor is used, it can be easily and quickly performed by extremely simple maintenance that only heat-treats the crack occurrence place without replacing the winding. It becomes possible to guarantee the insulation of the damaged winding.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

DESCRIPTION OF SYMBOLS 1a ... Flat conductor, 1b ... Inner coating, 1c ... Outer coating, 1d ... Insulation coating, 1A, 1B ... Winding (coil), 1A '... Winding (coil) after crack processing, 2 ... Stator core, 2a ... Teeth 2b ... yoke, 2c ... slot, B ... void, B '... foaming agent

Claims (3)

Consists of a conductive wire and an insulating coating formed around the conductive wire,
The insulating coating consists of an inner coating disposed on the conductor side and an outer coating disposed around the inner coating,
The outer coating is made of a thermosetting resin, and the inner coating is a winding made of a thermoplastic resin and a material containing therein a foaming agent having a foaming temperature higher than the softening point of the thermoplastic resin. A first step of winding the winding according to claim 1 around the teeth of the stator;
When cracks are generated in the insulating coating in the first step, the inner coating is softened by heat treatment at a temperature equal to or higher than the foaming temperature of the foaming agent, and the crack is closed with the inner coating softened by foaming of the foaming agent. A method of forming a coil comprising steps.   When a coil having a coil formed by winding the winding according to claim 1 around the teeth of the stator is cracked, the coil is heat-treated at a temperature equal to or higher than the foaming temperature of the foaming agent. A method for repairing a damaged coil, wherein the inner film is softened and the crack is closed by the inner film softened by foaming of the foaming agent.

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