JP2009194999A - Manufacturing method of stator coil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for simplifying a manufacturing method of stator where a stator coil having a crank type coil end is formed in a shape developed in the circumferential direction before being received in the slot of a stator core. <P>SOLUTION: Slot receiving conductor portions 103, i.e. coil conductor portions being received in a slot, are joined by pressure welding while touching the distal end faces 105 thereof tightly and then applied with an insulation coating thus manufacturing a circumferentially developing coil. Consequently, a circumferentially developing coil having a coil end of complicated profile and a short projection length in the axial direction can be manufactured easily. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a method for manufacturing a stator coil, and preferably relates to a method for manufacturing a stator coil having a coil end formed by bending an insulation-coated flat wire in a step shape.

Constructing the conductor wire constituting the stator coil with a rectangular wire having a large cross-sectional area is suitable for improving the slot space factor of the rotating electrical machine. For example, Patent Document 1 discloses a rotating electric machine having a structure in which a stator coil having a coil end formed in advance using this type of flat wire is housed in an open slot type or split core type stator core. Moreover, shortening the axial protruding length of the coil end is beneficial in terms of downsizing the rotating electrical machine. Particularly in a rotating electrical machine having a large diameter and a small axial protrusion length, the effect of shortening the axial protrusion length of the coil end is great.
Japanese Patent No. 3604326

  However, it is beneficial in terms of improving the slot space factor to adopt a rectangular wire shaped coil with a short coil end protruding in the axial direction and difficult to bend as a stator coil, but the coil end conductor part of each phase coil is complicated. Manufacturing an intertwined multiphase stator coil with a rectangular wire and reducing the coil end protrusion length required bending and braiding operations that are very difficult in actual manufacturing. In particular, in a multi-phase stator coil having a distributed winding structure, the coil end portion needs to be arranged with high density with other coil end portions adjacent in the radial direction and circumferential direction of the stator core. Spatial interference became a problem. In particular, the above-described problem is further caused in a coil end structure (hereinafter referred to as a stepped coil end) in which each coil end conductor portion is formed in a stepped shape and combined in a very high density to shorten the axial protrusion length of the coil end (hereinafter referred to as a stepped coil end). It becomes difficult.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to simplify the manufacturing process of a multiphase stator coil using a rectangular wire.

  The present invention requires a phase coil formed by alternately forming linear slot-accommodating conductor portions and coil end conductor portions by bending a predetermined coil end portion of an insulation-coated conductor wire obtained by insulating a rectangular wire. A multi-phase circumferentially-deployed coil having a distributed winding structure having a shape in which the multi-phase stator coil composed by combining the number of phases is developed in the circumferential direction is manufactured, and this circumferentially-deployed coil is sequentially inserted into the slots of the stator core. This is applied to a method for manufacturing a stator coil for manufacturing a stator coil (hereinafter, this stator coil is also simply referred to as a circumferentially deployed stator coil).

  In the present invention, in particular, a first coil comprising a part of the slot accommodating conductor part and the coil end conductor part on one end side, forming a part of the circumferentially expanded coil, a remaining part of the slot accommodating conductor part, and the like The coil end conductor portion on the end side, and the second coil forming the remaining portion of the circumferentially expanded coil is prepared in advance, and then the tip of the slot accommodating conductor portion of the first coil, and the second coil It is characterized in that the circumferentially-deployed coil is manufactured by abutting and joining the tip of the slot accommodating conductor portion.

  That is, in the present invention, the first and second coils, which are the circumferentially expanded coils each having the coil end conductor portion, are produced by dividing the circumferentially expanded coil at the slot accommodating conductor portion. Since the end of the coil accommodating part of the slot of two coils is joined to complete the circumferentially expanded coil, the process of intricately weaving the conductors of each phase coil at the coil end to complete the multiphase stator coil can be simplified. The effect which can simplify a process can be show | played. In addition, since the above-mentioned joining may be performed by joining the tips of the slot accommodating conductor portions of the first and second coils in the circumferentially developed shape, that is, the substantially planar shape, the joining work and the positioning work between the tips are facilitated. Can also be played. According to the present invention, it is possible to realize a circumferentially-deployed coil having a distributed winding structure by a simple process.

  In a preferred aspect, the joining is performed simultaneously on a plurality of slot accommodating conductor portions adjacent to each other in parallel. In this way, productivity, that is, work efficiency can be significantly improved. In the present invention, since the slot accommodating conductors are arranged in parallel with each other in the circumferentially expanded state, the arrangement and operation of the equipment for the simultaneous joining operation is very easy.

  In a preferred aspect, the slot accommodating conductors of the first and second coils are held while the tips of the slot accommodating conductor portions of the first and second coils are brought into contact with each other while being restrained from being displaced in a direction perpendicular to the longitudinal direction. By pressing the tips of the portions, the tips of the slot accommodating conductor portions of the first and second coils are pressed. That is, in this aspect, since the tips are pressed against each other at a predetermined pressure or higher to press-contact the tip surfaces, the joining can be realized by a simple process. Moreover, in this aspect, since a high temperature heating process is not required, an insulating film is not damaged. The tip surface can be cleaned before bonding by water cleaning, jet air flow spraying, alkali cleaning or acid cleaning.

  In a preferred aspect, the tips of the slot accommodating conductor portions of the first and second coils are brought into contact with each other, and ultrasonic energy is applied to the tips of the slot accommodating conductor portions of the first and second coils to join them. The ends of the slot accommodating conductor portions of the first and second coils are pressed. If it does in this way, the tip of each slot accommodation conductor part can be joined by excellent productivity. Preferably, the ultrasonic energy is applied to the other one of the first and second coils in the slot accommodating conductor, and the other is applied substantially perpendicular to the longitudinal direction of the slot accommodating conductor. In this way, productivity can be improved.

  In a preferred embodiment, a groove is provided at the tip of the slot accommodating conductor portion of the first coil, the tip of the slot accommodating conductor portion of the second coil is formed narrow, and the tip of the slot accommodating conductor portion of the second coil Is pressed into the tips of the slot accommodating conductors of the first coil to press the tips of the slot accommodating conductors of the first and second coils. In this way, it is possible to realize pressure welding (joining) by a simple process.

  In a preferred embodiment, the tips of the slot accommodating conductors of the first and second coils are joined by caulking the tips of the slot accommodating conductors of the first and second coils formed in a narrow width. In this way, it is possible to realize pressure welding (joining) by a simple process.

  In a preferred aspect, after joining the tips of the slot accommodating conductor portions of the first and second coils, the joined portions are covered with insulation. Thereby, the insulation failure in a junction part can be prevented.

  In a preferred embodiment, the joint portions of the two slot accommodating conductor portions adjacent in the radial direction or the circumferential direction in the same slot of the stator core are offset in the axial direction. As a result, the slot accommodating conductor portion is inserted into the slot by overlapping the bulge in the direction perpendicular to the longitudinal direction of the slot accommodating conductor portion due to bonding and the bulging of the slot accommodating conductor portion due to the insulation coating in the radial direction or circumferential direction. Can be prevented from becoming difficult.

  In a preferred aspect, the coil end conductor portion is bent in a staircase shape having alternately protruding portions in the longitudinal direction of the slot accommodating conductor portion and extending portions in the developing direction. Thereby, a rectangular wire multiphase stator coil having a distributed winding structure having a coil end with a short axial protrusion length can be realized by a simple operation.

   An embodiment in which the coil end conductor portion of each conductor is formed in a step shape will be described below. It should be noted that the present invention should not be construed as being limited to the following embodiments, and the technical idea of the present invention may be realized by a combination of other known techniques.

(Description of stator)
First, a stator coil (hereinafter referred to as a crank type stator coil) of this embodiment in which coil end conductor portions of each conductor are formed in a step shape will be described with reference to FIGS. FIG. 1 is a partial perspective view showing an insulating coated rectangular wire 30 that forms one conductor of a crank type stator coil, and FIG. 2 shows a crank type coil end that is an assembly of stepped coil end portions 42. It is a fragmentary perspective view.

  11 is a stator, 12 is a stator core, 13 is an end face of the stator core 12, and 20 is a stator coil. The stator 11 is used for a generator motor for driving a vehicle. A rotor (not shown) is rotatably accommodated inside the stator 11 in the radial direction. A large number of magnetic poles having different polarities alternately in the circumferential direction are formed by permanent magnets on the outer periphery of the rotor. The outer peripheral surface of the rotor faces the inner peripheral surface of the stator 11 via a minute air gap. The stator core 12 is formed by laminating electromagnetic steel plates having a predetermined thickness in the axial direction. The stator coil 20 is a three-phase winding. A single-phase wave winding is wound around the slot 14, and a single-phase wave winding is wound around the slot 15. In other words, a stator coil 20 having the same phase is wound around two slots 14 and 15 adjacent to each other to form a so-called two-slot structure for each pole and each phase.

  One phase coil (wave winding) of the stator coil 20 is formed by bending the insulation-coated rectangular wire 30 and then accommodating it in the open slot structure slot 14 or 15 of the stator core 12. Of course, a split stator core structure may be employed instead of the open slot structure.

  The insulating covering rectangular wire 30 is formed by coating an enamel layer such as polyamide imide on a copper wire having a substantially rectangular cross section, and further covering an outer side with an extrusion covering resin layer such as PPS. The total thickness of the insulating film is set to 100 μm to 170 μm. However, the insulation coating structure of the insulation coating rectangular wire 30 may adopt another known method. In this embodiment, the plurality of insulation coated rectangular wires 30 are arranged in a line in the slot depth direction in the slot, but the present invention is not limited to this, and may be arranged in a matrix in the slot. In addition, it is usual to provide insulating paper on the inner surface of the slot. However, in this embodiment, the insulating paper is omitted because a two-layer insulating layer is formed. The stator coil 20 will be further described. The insulation-coated rectangular wire 30 forming the stator coil 20 is separated from the slot accommodating portions 40 accommodated in the slots 14 and 15 of the stator core 12 respectively by two magnetic pole pitches extending in the axial direction and the circumferential direction while being separated by approximately one magnetic pole pitch in the circumferential direction. A coil end portion 42 that connects the end portions of the two slot accommodating portions 40 at both axial ends of the stator core 12 is provided.

(Description of shape of coil end portion 42)
The coil end portion 42 of the insulating coated rectangular wire 30, that is, the coil end conductor portion referred to in the present invention will be described in more detail with reference to FIG.

  At the center in the circumferential direction of the coil end portion (also referred to as a stepped coil end portion) 42 is provided a crown portion 1 that is a circumferential line portion that is located on the outermost side in the axial direction and extends in the circumferential direction. The part 42 is bent stepwise from the top part (circumferential line part) 1 toward the slot accommodating parts 40 on both sides. A step (also referred to as a step in the thickness direction) 3A is provided in the central portion of the top portion (circumferential line portion) 1 in the radial direction (thickness direction) by substantially the thickness of the insulating covering rectangular wire 30. This thickness direction step 3A is a step for allowing the coil end portion 42 and the other half portion to overlap each other in the radial direction by allowing the conductor end portion to overlap the other coil end portion. It is. 2 to 4 are circumferential line portions extending in the circumferential direction, and 6 to 8 are axial line portions extending in the axial direction. C1 to C6 are corner portions forming a boundary portion between one adjacent circumferential line portion and one axial line portion. C <b> 7 is a corner portion that forms a boundary portion between the circumferential line portion 4 and the slot accommodating portion 40. The coil end portion 42 is formed in a step shape from the outermost crown 1 in the axial direction toward the left and right slot accommodating portions 40. In FIG. 3, the corners C1 to C7 are shown at right angles, but actually, the corners C1 to C7 are bent or curved with a predetermined radius of curvature within a range in which high-density mounting with other adjacent coil end portions 42 is possible. It only has to be. By combining the coil end portions 42, a crank type coil end of the stator coil is formed as shown in FIG.

(First manufacturing method)
A first manufacturing method using the pressure welding method will be described with reference to FIGS. FIG. 5 is a schematic partial perspective view for explaining the press-contacting process, and FIG. 6 is a schematic partial cross-sectional view showing a state where the coil end conductor portion is clamped by the clamping biasing member.

(Semi-coil conductor manufacturing process)
First, a large number of first coils 101 and second coils 102 each having a half turn (also referred to as a half-coil conductor) of each coil conductor developed in a distributed winding shape in the circumferential direction are manufactured. The first coil 101 and the second coil 102 are formed in the same shape, and each of them is accommodated in a linear slot of approximately half the length by bending a predetermined coil end portion of an insulation-coated conductor wire obtained by insulation-coating a flat wire. It is comprised by the conductor parts 103 and 103 and the coil end conductor part 104 bent in the step shape. The two slot accommodating conductor portions 103 extend in parallel with an electrical angle π away from both ends of the coil end conductor portion 104. The manufacture of the stepped coil end itself is not the gist of the present invention, and the coil end conductor portion 104 of this embodiment does not necessarily have a stepped shape. Therefore, the description of the bending process of the coil end conductor portion 104 is omitted. To do.

(Clamping process)
Next, the front end surface 105 of the slot accommodating conductor 103 of the first coil 101 and the front end surface 105 of the slot accommodating conductor 103 of the second coil 102 are brought into close contact with each other. In this embodiment, this close contact is performed using the clamping and biasing members 201 and 202 shown in FIG. The sandwiching and urging member 201 has a vertical end surface 203 extending in the vertical direction and in the longitudinal direction of the slot accommodating conductor portion 103, and a horizontal plane 204 extending in the horizontal direction and in the longitudinal direction of the slot accommodating conductor portion 103. The end surface 203 and the horizontal plane 204 are in contact with each other at a right angle. The sandwiching / urging member 202 has a vertical end surface 205 extending in the vertical direction and in the longitudinal direction of the slot accommodating conductor portion 103, and can advance and retreat on the lateral plane 204 of the sandwiching / urging member 201 in the left-right direction (circumferential development direction) Is arranged. The pinching and urging member 202 is advanced and retracted in the left-right direction by an unillustrated actuator.

  Note that the first clamp pair including the clamping biasing members 201 and 202 for clamping the slot accommodating conductor 103 of the first coil 101 shown in FIG. 5 and the slot accommodating conductor of the second coil 102 shown in FIG. A second clamp pair made up of sandwiching biasing members 201 and 202 for sandwiching 103 is provided. The vertical end surfaces 203 of these two clamp pairs constitute the same plane, and the horizontal planes 204 of these two clamp pairs also constitute the same plane.

  Next, the slot accommodating conductor 103 of the first coil 101 is placed on the horizontal plane 204 of the clamping biasing member 201 of the first clamp pair, and on the horizontal plane 204 of the clamping biasing member 201 of the second clamp pair. The slot accommodating conductor 103 of the second coil 102 is placed. Next, by urging the clamping biasing member 202 of the first clamp pair to the left, the slot accommodating conductor portion 103 of the first coil 101 is clamped at a predetermined pressure by the clamping biasing members 201 and 202 of the first clamp pair. Then, by urging the clamping biasing member 202 of the second clamp pair to the left, the slot accommodating conductor portion 103 of the second coil 102 is clamped at a predetermined pressure by the clamping biasing members 201 and 202 of the second clamp pair. . That is, in FIG. 6, the horizontal clamp method is adopted.

(Pressing process)
Next, the second clamp pair is pressed toward the first clamp pair by a predetermined pressing force in the longitudinal direction of the slot accommodating conductor 103 by an unillustrated actuator. This pressing force is large enough to press the front end surface 105 of the slot accommodating conductor portion 103 of the first coil 101 and the front end surface 105 of the slot accommodating conductor portion 103 of the second coil 102, and the above-mentioned clamping force The clamping force of the urging members 201 and 202 is set such that no slip occurs between the clamping urging members 201 and 202 and the slot accommodating conductor portion 103 during the press contact. Thereby, the front end surfaces 105 and 105 that are in close contact with each other are brought into pressure contact.

(Resin coating process)
Next, a resin liquid is applied to the vicinity of the front end surface 105 of the slot accommodating conductors 103 and 103 and solidified to electrically insulate the periphery of the front end surface 105.

(Modification)
Different shapes of the holding and biasing members 201 and 202 will be described with reference to FIGS. The first clamp pair 301 for sandwiching the slot accommodating conductor portion 103 of the first coil 101 and the second clamp pair 302 for sandwiching the slot accommodating conductor portion 103 of the second coil 102 are used, respectively. The point which urges | biases clamp pair 301,302 which clamps the accommodation conductor part 103 to a press-contact direction is the same as the said embodiment.

  However, in this embodiment, the lower clamping biasing member 201 has a shallow groove 206 in which the lower portion of the slot accommodating conductor 103 is accommodated as shown in FIG. 8, and the upper clamping biasing member 202 is accommodated in the slot accommodation. It has a flat bottom surface 207 that presses the conductor portion 103 downward from above. That is, in FIG. 6, FIG. 7, the vertical clamp system is employ | adopted. Even in this way, pressure contact can be performed.

(Modification)
In the above description, the state in which the two slot accommodating conductor portions 103 and 103 are pressed into one slot accommodating conductor portion 103 has been described. However, a plurality of pairs of slot accommodating conductor portions 103 and 103 developed in the circumferential direction are described. It can be easily understood by those skilled in the art that a part of the urging and urging members can be shared in this simultaneous pressure welding, and the description thereof will be omitted. FIG. 9 schematically shows a mode in which the four pairs of slot accommodating conductors 103 and 103 are simultaneously pressed by the vertical clamp method.

(Second manufacturing method)
A second manufacturing method using the ultrasonic bonding method will be described with reference to FIG. The clamping and biasing members 201 and 202 constituting the first clamp pair 301 sandwich the slot accommodating conductor portion 103 of the first coil 101, and the clamping and biasing members 201 and 202 constituting the second clamp pair 302 are The point of sandwiching the slot accommodating conductor 103 of the second coil 102 and the point of contact of the tip surfaces 105 of the two slot accommodating conductors 103 facing each other are the same as in the second manufacturing method described above.

  In this manufacturing method, in a state where the slot accommodating conductor portion 103 of the first coil 101 is fixed by the first clamp pair 301, the second clamp pair 302 is clamped by sandwiching the slot accommodating conductor portion 103 of the second coil 102. The sandwiching and urging members 201 and 202 that are configured are vibrated in the vertical direction by an ultrasonic vibrator. If it does in this way, the front end surfaces 105 and 105 of the two slot accommodating conductor parts 103 which are mutually aligned and contact | abutted will be heated by friction heat, will become high temperature, and will contact | adhere. Since the ultrasonic energy is applied for a very short time, the heat does not cause thermal degradation of the slot accommodating conductor coating resin at a position away from the front end surface 105. The application of ultrasonic energy is preferably performed while pressing the tip surfaces of the two slot accommodating conductor portions 103 together. Moreover, you may give an ultrasonic vibration to a horizontal direction, ie, the circumferential direction expansion | deployment direction.

(Third production method)
A third manufacturing method, which is a modification of the pressure welding method, will be described with reference to FIG. This manufacturing method is characterized in that, when the above-described pressure welding method is adopted, a V-groove is provided at the tip of one slot housing conductor 103 and the tip of the other slot housing conductor 103 is tapered. There is. The tapered tip portion 111 of the other slot accommodating conductor 103 has flat slopes 112 and 113, and the V groove 114 of the one slot accommodating conductor 103 has an acute angle θ degree formed by the flat slopes 112 and 113. It has a slightly smaller angle. The sandwiching and urging members 201 and 202 constituting the second clamp pair 302 constitute the first clamp pair 301. When pressed in the longitudinal direction of the slot accommodating conductor portion 103 toward the clamping biasing members 201 and 202, plastic deformation occurs between the flat inclined surfaces 112 and 113 and the surface of the V-groove 114, and both are pressed against each other with a small pressing force. Can.

(Fourth manufacturing method)
A fourth manufacturing method, which is a modification of the pressure welding method, will be described with reference to FIG. In this manufacturing method, when the above-described pressure welding method is adopted, the slope 121 is provided at the tip of one slot accommodating conductor 103, and the slope 122 is provided at the tip of the other slot accommodating conductor 103. There are features. However, in this manufacturing method, in order to simplify the apparatus, the slot accommodating conductor portion 103 of the first coil 101 and the slot accommodating conductor portion 103 of the second coil 102 are clamped by the common clamping biasing members 401 and 402, Aligned.

  In a state where the slopes 121 and 122 are in contact with each other, the clamping biasing member 201 is fixed and the clamping biasing member 202 is pressed downward, so that the slopes 121 and 122 that are in contact with each other are pressed or caulked.

(Modification)
In the above-described embodiment, the bonding is performed at the central portion in the longitudinal direction of the slot accommodating conductor 103. However, the joining portion of the two slot accommodating conductors 103 adjacent in the radial direction or the circumferential direction of the same slot is It is preferable to shift to As a result, the slot accommodating conductor portion is inserted into the slot by overlapping the bulge in the direction perpendicular to the longitudinal direction of the slot accommodating conductor portion due to bonding and the bulging of the slot accommodating conductor portion due to the insulation coating in the radial direction or circumferential direction. Can be prevented from becoming difficult.

It is a typical fragmentary perspective view which shows one coil conductor which has a step-like coil end conductor part. It is a typical fragmentary perspective view of the crank type coil end of the stator coil formed by combining the coil conductors shown in FIG. FIG. 4 is a schematic development view in the circumferential direction of one coil end conductor portion. 3n is a partial circumferential development plan view showing a circumferential development state of a crank type coil end combined with a coil end conductor portion 104. FIG. It is a model perspective view which shows the principle of a pressure welding method. FIG. 6 is a longitudinal sectional view showing a state in which a slot accommodating conductor portion is clamped by a clamping urging member used in the press contact method shown in FIG. 5. It is a model partial longitudinal cross-sectional view which shows the deformation | transformation aspect pinched in the vertical direction. FIG. 8 is a longitudinal sectional view showing a state in which a slot accommodating conductor portion is clamped by a clamping biasing member used in FIG. 7. It is a schematic top view which shows the state which press-contacts several slot accommodation conductor parts simultaneously. It is a model partial side view explaining an ultrasonic bonding method. It is a model partial side view explaining the deformation | transformation aspect of a press-contact method. It is a model partial side view explaining the deformation | transformation aspect of a press-contact method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Stator 12 Stator core 14 Slot 15 Slot 20 Stator coil 30 Insulation covering rectangular wire 40 Slot accommodating part 42 Coil end part 42 Each coil end part 101,102 Coil 103 Slot accommodating conductor part 104 Coil end conductor part 105 Tip end face 111 Tapered tip part 112, 113 Flat slope 114 V groove 121 Slope 122 Slope 201 Clamping biasing member 202 Clamping biasing member 203 Vertical end surface 204 Horizontal plane 205 Vertical end surface 206 Shallow groove 207 Bottom surface 301, 302 Clamp pair 401, 402 Clamping biasing member

Claims (9)

By bending the planned coil end portion of the insulation coated conductor wire formed by insulating the rectangular wire, the number of phase coils formed by alternately forming the linear slot accommodating conductor portion and the coil end conductor portion is equal to the required number of phases. A multi-phase circumferentially expanded coil having a distributed winding structure having a shape in which circumferentially expanded multiphase stator coils configured in combination with each other are manufactured, and this circumferentially expanded coil is sequentially inserted into the slots of the stator core, and the stator coil In the stator coil manufacturing method for manufacturing
A first coil comprising a part of the slot accommodating conductor part and the coil end conductor part on one end side, forming a part of the circumferentially expanded coil, and a remaining part of the slot accommodating conductor part and the coil on the other end side A second coil comprising an end conductor portion and forming the remaining portion of the circumferentially expanded coil in advance, and then the tip of the slot accommodating conductor portion of the first coil and the slot accommodating conductor portion of the second coil A stator coil manufacturing method, wherein the circumferentially-deployed coil is manufactured by abutting and joining the tip of the stator coil.   The method of manufacturing a stator coil according to claim 1, wherein the joining is performed simultaneously on a plurality of slot accommodating conductor portions adjacent to each other in parallel.   The tips of the slot accommodating conductors of the first and second coils are brought into contact with each other and held while restraining displacement in a direction perpendicular to the longitudinal direction, and the tips of the slot accommodating conductors of the first and second coils are pressed. The method of manufacturing a stator coil according to claim 1, wherein the tips of the slot accommodating conductor portions of the first and second coils are pressed against each other.   By contacting the tips of the slot accommodating conductors of the first and second coils and applying ultrasonic energy to the tips of the slot accommodating conductors of the first and second coils, the first and second coils are joined. The stator coil manufacturing method according to claim 1, wherein the tips of the coil's slot accommodating conductors are joined.   A groove is provided at the tip of the slot accommodating conductor portion of the first coil, the tip of the slot accommodating conductor portion of the second coil is formed narrow, and the tip of the slot accommodating conductor portion of the second coil is the first coil. The stator coil manufacturing method according to claim 1, wherein the ends of the slot accommodating conductor portions of the first and second coils are joined by press-fitting into the ends of the slot accommodating conductor portions.   2. The stator according to claim 1, wherein the tips of the slot accommodating conductors of the first and second coils are joined by caulking the tips of the slot accommodating conductors of the first and second coils formed in a narrow width. Coil manufacturing method.   The method for manufacturing a stator coil according to claim 1, wherein after the tips of the slot accommodating conductor portions of the first and second coils are joined, the joined portions are insulated.   The method for manufacturing a stator coil according to claim 1, wherein joint portions of the two slot accommodating conductor portions adjacent in the radial direction or the circumferential direction in the same slot of the stator core are displaced in the axial direction.   The method of manufacturing a stator coil, wherein the coil end conductor portion has a portion protruding in a substantially longitudinal direction of the slot accommodating conductor portion and a portion extending in a deployment direction alternately and is bent in a step shape.

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