WO2021019749A1

WO2021019749A1 - Stator manufacturing method

Info

Publication number: WO2021019749A1
Application number: PCT/JP2019/030100
Authority: WO
Inventors: 敬大遠井; 稔粟津; 翔吾新谷
Original assignee: 株式会社東芝; 東芝インフラシステムズ株式会社
Priority date: 2019-07-31
Filing date: 2019-07-31
Publication date: 2021-02-04
Also published as: JPWO2021019749A1; JP6922118B2

Abstract

Provided is a stator manufacturing method with which a reduction in size is possible. A plurality of coil segments 19 are prepared in an embodiment, said coil segments 19 having a pair of mutually opposed straight-line sections 19a formed by bending a rectangular conductor, and a cross-link section 19b that interconnects one end of each of the pair of straight-line sections 19a. Each of the straight-line sections 19a have, at the distal ends thereof, a low-rigidity section 19a2 having a smaller cross-sectional area lower rigidity than in other regions of the rectangular conductor. In a state where the distal end of the straight-line section 19a is gripped by a bending jig 101, the bending tool 101 and/or a stator core 16 is caused to rotate relative to the circumferential direction of the stator core 16, an extension end section 19a1 is bent in the circumferential direction of the stator core 16 between the low-rigidity section 19a2 and another end surface 16b, the low-rigidity section 19a2 is cut to form a junction 19a5, and junctions 19a5 that are adjacent in the radial direction of the stator core 16 are joined to each other.

Description

Stator manufacturing method

An embodiment of the present invention relates to a method for manufacturing a stator.

The rotary electric machine has a tubular stator and a rotor rotatably provided with respect to the stator. The stator has a stator core formed by laminating a large number of annular electromagnetic steel sheets, and a coil attached to the stator core. A coil formed by joining a plurality of coil segments has a coil end that projects axially from both end faces of the stator core. In recent years, further miniaturization of the stator of a rotary electric machine has been desired.

Japanese Patent No. 4412330

An object of the embodiment of the present invention is to provide a method for manufacturing a stator that can be miniaturized.

The method for manufacturing a stator of the embodiment is formed by bending a flat conductor, and has a pair of straight portions facing each other and a crosslinked portion connecting one ends of the pair of straight portions, and each of the straight portions has a bridge portion. , Prepare a plurality of coil segments having a low rigidity portion having a smaller cross-sectional area and lower rigidity than other regions of the flat conductor at the tip portion. The straight portions of the plurality of coil segments are inserted into a plurality of slots from one end surface side of the stator core, and a plurality of extending ends protruding from the other end surface side of the stator core in a predetermined length axial direction are formed. By constructing and arranging a plurality of the straight portions in each slot side by side in the radial direction, the plurality of the extending end portions are arranged in a cylindrical shape having a plurality of layers coaxial with the stator core. With the tip of the straight portion gripped by the folding jig, at least one of the bending jig and the stator core is relatively rotated in the circumferential direction of the stator core to extend the rod. The end portion is bent in the circumferential direction of the stator core between the low rigidity portion and the other end surface side. The low-rigidity portion is cut to form a joint portion. The joint portions adjacent to each other in the radial direction of the stator core are joined to each other.

FIG. 1 is a vertical sectional view showing a rotary electric machine according to an embodiment. FIG. 2 is a cross-sectional view showing a rotary electric machine. FIG. 3 is a perspective view showing the other end surface side of the stator of the rotary electric machine. FIG. 4 is an enlarged perspective view showing the coil end portion of the coil segment of the stator in the region A of FIG. FIG. 5 is a perspective view showing a coil segment. FIG. 6 is a perspective view showing coil segments arranged in a cylindrical shape on a stator core. FIG. 7 is an enlarged perspective view showing a coil segment in region B of FIG. FIG. 8 is a perspective view showing a stator assembly in which a coil segment is attached to the stator core of FIG. FIG. 9 is a perspective view showing the coil segments in which all the coil segments are mounted on the stator core and the coil segments are shown in different directions. FIG. 10 shows a bending step (first time) of 48 coil segments located in the sixth layer (outermost layer) of the coil segments mounted on the stator core, and is first (1) by a folding jig. The perspective view which shows the state just before bending and forming 48 coil segments of the outermost layer in the second). FIG. 11 is an enlarged perspective view showing the region C of FIG. 10. FIG. 12 is an enlarged side view showing the area C of FIG. 10. FIG. 13 is a perspective view showing a state immediately after bending and molding 48 coil segments from the state of FIG. FIG. 14 is an enlarged perspective view showing the region D of FIG. FIG. 15 is an enlarged side view showing the area D of FIG. FIG. 16 is a side view showing bending molding of the coil segment. FIG. 17 is a perspective view showing a cutting process of the coil segment. FIG. 18 shows a bending step (sixth time) of 48 coil segments located in the first layer (innermost layer) of the coil segments mounted on the stator core, and is the last (6th) by the bending jig. The perspective view which shows the state just before bending and forming 48 coil segments of the innermost layer in the second). FIG. 19 is a perspective view showing a state immediately after bending and molding 48 coil segments from the state of FIG. FIG. 20 is a perspective view showing a joining process of coil segments. FIG. 21 is a side view showing bending molding of the coil segment of the modified example 1 of the embodiment. FIG. 22 is a side view showing bending molding of the coil segment of the modified example 2 of the embodiment. FIG. 23 is a side view showing bending molding of the coil segment of the modified example 3 of the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The disclosure is merely an example, and the invention is not limited by the contents described in the following embodiments. Modifications that can be easily conceived by those skilled in the art are naturally included in the scope of disclosure. In order to clarify the explanation, in the drawings, the size, shape, etc. of each part may be changed with respect to the actual embodiment and represented schematically.

(Embodiment)
First, an example of the rotary electric machine 10 to which the stator 12 according to the embodiment is applied will be described.
FIG. 1 is a vertical cross-sectional view of the rotary electric machine 10 according to the embodiment, and shows only one half of the rotary electric machine 10 with the central axis C1 as the center. FIG. 2 is a cross-sectional view of the rotary electric machine 10.

As shown in FIG. 1, the rotary electric machine 10 is configured as, for example, a permanent magnet type rotary electric machine. The rotary electric machine 10 includes an annular or cylindrical stator 12, a rotor 14 that is rotatable inside the stator 12 around the central axis C1 and is coaxially supported with the stator 12, and these stators. A casing 30 that supports the rotor 12 and the rotor 14 is provided.
In the following description, the extending direction of the central axis C1 is referred to as an axial direction Z, the direction of rotation around the central axis C1 is referred to as a circumferential direction, and the axial direction Z and the direction orthogonal to the circumferential direction are referred to as a radial direction.

As shown in FIGS. 1 and 2, the stator 12 includes a cylindrical stator core 16 and a rotor winding (coil) 18 wound around the stator core 16. The stator core 16 is formed by laminating a large number of annular electromagnetic steel plates 17 made of a magnetic material, for example, silicon steel, in a concentric manner. A large number of electrical steel sheets 17 are connected to each other in a laminated state by welding a plurality of locations on the outer peripheral surface of the stator core 16. The stator core 16 has one end surface 16a located at one end in the axial direction and the other end surface 16b located at the other end in the axial direction. One end surface 16a and the other end surface 16b extend orthogonally to the central axis C1.

A plurality of slots 20 are formed in the inner peripheral portion of the stator core 16. The plurality of slots 20 are arranged at equal intervals in the circumferential direction. Each slot 20 opens on the inner peripheral surface of the stator core 16 and extends in the radial direction from the inner peripheral surface. Each slot 20 extends over the entire length of the stator core 16 in the axial direction Z. One end of each slot 20 is open to one end surface 16a, and the other end is open to the other end surface 16b. It should be noted that each slot 20 may be configured not to open on the inner peripheral surface of the stator core 16. In the present embodiment, an example is shown in which each slot 20 extends over the entire length of the stator core 16 in the axial direction Z, but each slot 20 is provided at an angle with respect to the axial direction Z, so-called skew. It may be in shape.
By forming the plurality of slots 20, the inner peripheral portion of the stator core 16 constitutes a plurality of (for example, 48 in the embodiment) teeth 21 projecting toward the central axis C1. The teeth 21 are arranged at equal intervals along the circumferential direction. As described above, the stator core 16 integrally has an annular yoke portion and a plurality of teeth 21 protruding in the radial direction from the inner peripheral surface of the yoke portion toward the central axis C1.

Coil 18 is embedded in a plurality of slots 20 and wound around each tooth 21. The coil 18 has coil ends 18a and 18b extending outward in the axial direction from one end surface 16a and the other end surface 16b of the stator core 16. By passing an alternating current through the coil 18, a predetermined interlinkage magnetic flux is formed in the stator 12 (teeth 21).

In the example shown in FIG. 1, iron core end plates 24 having substantially the same cross-sectional shape as the stator core 16 are provided at both ends of the stator core 16 in the axial direction. Further, an iron core retainer 26 is provided on these iron core end plates 24.
The casing 30 has a substantially cylindrical first bracket 32a and a bowl-shaped second bracket 32b. The first bracket 32a is connected to the iron core retainer 26 located on the drive end side of the stator core 16. The second bracket 32b is connected to the iron core retainer 26 located on the opposite drive end side. The first and

second brackets

32a and 32b are made of, for example, an aluminum alloy. An annular bearing bracket 34 is coaxially fastened to the tip end side of the first bracket 32a with bolts. For example, a first bearing portion 36 incorporating a roller bearing 35 is fastened to the central portion of the bearing bracket 34. A second bearing portion 38 containing, for example, a ball bearing 37 is fastened to the central portion of the second bracket 32b.

On the other hand, the rotor 14 has a cylindrical shaft (rotating shaft) 42 rotatably supported by the first and

second bearing portions

36 and 38 about the central axis C1 and a substantially central portion in the axial direction of the shaft 42. It has a cylindrical rotor core 44 fixed to the rotor core 44, and a plurality of permanent magnets 46 embedded in the rotor core 44. The rotor core 44 is configured as a laminated body in which a large number of magnetic materials, for example, a large number of annular electromagnetic steel plates 47 such as silicon steel are laminated concentrically. The rotor core 44 has an inner hole 48 formed coaxially with the central axis C1. The shaft 42 is inserted and fitted into the inner hole 48 and extends coaxially with the rotor core 44. A substantially disk-shaped magnetic shielding plate 54 and a rotor core retainer 56 are provided at both ends of the rotor core 44 in the axial direction.

As shown in FIGS. 1 and 2, the rotor core 44 is coaxially arranged with a slight gap (air gap) inside the stator core 16. That is, the outer peripheral surface of the rotor core 44 faces the inner peripheral surface (tip surface of the teeth 21) of the stator core 16 with a slight gap.

A plurality of magnet embedding holes penetrating in the axial direction Z are formed in the rotor core 44. A permanent magnet 46 is loaded and arranged in each magnet embedding hole, and is fixed to the rotor core 44 by, for example, an adhesive or the like. Each permanent magnet 46 extends over the entire length of the rotor core 44. Further, the plurality of permanent magnets 46 are arranged at predetermined intervals in the circumferential direction of the rotor core 44.

As shown in FIG. 2, the rotor core 44 has a d-axis extending in the radial direction or the radial direction of the rotor core 44, and a q-axis electrically separated from the d-axis by 90 °. Here, the axis extending in the radial direction through the boundary between adjacent magnetic poles and the central axis C1 is defined as the q-axis, and the direction electrically perpendicular to the q-axis is defined as the d-axis. The d-axis and the q-axis are provided alternately in the circumferential direction of the rotor core 44 and in a predetermined phase.

Two permanent magnets 46 are arranged on both sides of each d-axis in the circumferential direction of the rotor core 44. Each permanent magnet 46 is formed in an elongated flat plate shape having a rectangular cross section, and has a length substantially equal to the axial length of the rotor core 44. When viewed in a cross section orthogonal to the central axis C1 of the rotor core 44, the permanent magnets 46 are respectively inclined with respect to the d-axis. The two permanent magnets 46 are arranged side by side in a substantially V shape, for example. Here, the ends of the permanent magnets 46 on the inner peripheral side are adjacent to the d-axis and face each other with a slight gap. The outer peripheral end of the permanent magnet 46 is separated from the d-axis along the circumferential direction of the rotor core 44, and is located near the outer peripheral surface of the rotor core 44 and near the q-axis. As a result, the outer peripheral end of the permanent magnet 46 is adjacent to the outer peripheral end of the permanent magnet 46 of the adjacent magnetic poles with the q-axis in between. In the present embodiment, the permanent magnets 46 are inclined with respect to the d-axis, but the permanent magnets 46 may be perpendicular to the d-axis.

FIG. 3 is a perspective view showing the other end surface side of the stator, FIG. 4 is a perspective view showing an enlarged view of the second coil end portion of the stator in the region A of FIG. 3, and FIG. 5 shows a coil segment. It is a perspective view which shows. As shown in FIGS. 3 and 4, the coil 18 is configured by using a plurality of coil segments 19 and is assembled to the stator core 16. Each coil segment 19 is formed as a flat conductor by a flat copper wire having a rectangular cross section. The flat line has a substantially rectangular cross section (cross section) perpendicular to the longitudinal direction, or has a shape having at least two opposite long sides. When the cross section of the flat conductor is rectangular, the four corners do not have to be right angles and may be chamfered or rounded. When the cross section has two long sides facing each other, the portion connecting the ends of the two long sides facing each other in the cross section may be curved, for example, in an oval shape. As for the material of the flat conductor, a conductor such as aluminum may be used in addition to copper.

As shown in FIG. 5, the coil segment 19 is formed into a U-shape with both ends refracted by cutting and bending a flat wire. That is, the coil segment 19 integrally has a pair of straight line portions 19a facing each other at intervals and a bridging portion 19b connecting one ends of the straight line portions 19a. The coil segment 19 has a rectangular cross-sectional shape, i.e., the cross-section has a pair of long sides facing each other and a pair of short sides facing each other. The outer surface of the coil segment 19 is covered with an insulating coating 19c (indicated by dots) such as enamel. The insulating film 19c has been removed from the extending end of each straight portion 19a so that it can be conducted. The extending end portion 19a1 has a joint portion 19a5 inclined at an angle θ1 (less than 90 °) with respect to the central axis C2 of the straight line portion 19a at the tip end portion thereof. The joint portion 19a5 is formed in a rectangular shape, a pair of long sides are inclined by an angle θ1 with respect to the central axis C2, and a pair of short sides extend in a direction orthogonal to the central axis C2. The insulating coating 19c shown by dots in FIG. 5 is not shown in drawings other than FIG.

As shown in FIG. 3, the plurality of coil segments 19 are arranged in a plurality of cylinders, here in a six-layer cylindrical shape, and a pair of linear portions 19a of each coil segment are, for example, one of the stator cores 16. It is inserted into the corresponding different slots 20 from the end surface 16a side, and protrudes from the other end surface 16b of the stator core 16 by a predetermined length. As shown in FIG. 2, for example, six straight line portions 19a are inserted into one slot 20. In the slot 20, the six straight portions 19a are arranged side by side in the radial direction of the stator core 16. The six straight lines 19a are arranged in the slot 20 with their long sides facing each other in parallel.

The crosslinked portion 19b of the coil segment 19 faces the one end surface 16a of the stator core 16 with a slight gap. The cross-linking portion 19b extends substantially along the circumferential direction of the stator core 16, and some cross-linking portions 19b extend so as to intersect with other cross-linking portions 19b. These cross-linked portions 19b form a coil end 18a protruding from one end surface 16a.

As shown in FIGS. 3 and 4, the straight portion 19a of the coil segment 19 extends from the other end surface 16b of the stator core 16 in the predetermined length axial direction Z to form the extending end portion 19a1. The extending end portion 19a1 is bent in the circumferential direction of the stator core 16 and extends so as to be inclined with respect to the axial direction Z. Specifically, the extending end portion 19a1 of each straight portion 19a is a first bent portion 19M that bends at a predetermined angle in the circumferential direction from the axial direction Z of the stator core 16 and the first bent portion 19M with respect to the axial direction Z. It has an inclined portion 19N that is inclined and extends linearly. The joint portion 19a5 located at the tip of the extension end portion 19a1 is located substantially parallel to the other end surface 16b of the stator core 16.

The extending end portions 19a1 of the six straight portions 19a inserted into each slot 20 are alternately bent in one direction and the opposite direction. That is, the extending end portion 19a1 located on the innermost circumference is bent in one direction in the circumferential direction of the stator core 16, and the extending end portion 19a1 on the outer side is in the other direction (opposite direction) in the circumferential direction. It is bent into. Further, the extending end portion 19a1 on the outer side is bent in one direction. The six extending end portions 19a1 extending from the plurality of different slots 20 are bent so that the joint portions 19a5 are located substantially in a line in the radial direction of the stator core 16. These six joints 19a5 extend substantially in the same plane. The portion of the extending end of each straight portion 19a from which the insulating coating 19c is removed is preferably the portion on the stator core 16 side adjacent to the joint portion 19a5. By doing so, when the joint portions 19a5 of the coil segments 19 adjacent to each other in the radial direction are joined by welding as described later, the insulating coating 19c adjacent to the stator core 16 side is removed from the joint portion 19a5. The welded part can be reliably conducted. When the low-rigidity portion 19a2 described later is provided near (for example, adjacent to) the joint portion 19a5, the stator core 16 of the portions adjacent to the low-rigidity portion 19a2 among the extending ends of the straight portions 19a. The insulating coating 19c on the side portion may be removed.

The tip surfaces of the extending end portions 19a1 of each row arranged in the radial direction, that is, the joining portions 19a5 are mechanically and electrically joined to each other by two (two each). For joining, for example, laser welding can be used. The weld bead 19d is formed by irradiating the two joints 19a5 with laser light to partially melt the conductor. Two joints 19a5 adjacent to each other in the radial direction are joined to form a three-phase coil 18 in the entire plurality of coil segments. The extending end portion 19a1 constitutes a coil end 18b protruding from the other end surface 16b of the stator core 16. The tip portion (conductive portion) including the joint portion (welded surface) of the straight portion 19a is covered with an insulating material (not shown) such as powder coating or varnish.
As shown in FIG. 3, a U-phase connection terminal TU, a V-phase connection terminal TV, and a W-phase connection terminal TW are connected to three of the coils 18, respectively.

Next, an example of a method of manufacturing the stator 12 of the rotary electric machine 10 according to the embodiment will be described.
The mounting process of mounting the coil segment 19 on the stator core 16 will be described with reference to FIGS. 6 to 9.
FIG. 6 is a perspective view showing the stator core 16 and the coil segments 19 arranged in a cylindrical shape.
As shown in FIG. 6, first, a large number of coil segments 19 are prepared, and these are arranged in a cylindrical shape. Although not shown, three sets of coil segments 19 each arranged in a cylindrical shape are prepared. One set (48 pieces) of coil segments 19 are arranged in a cylindrical shape along a plurality of slots 20 of the stator core 16. One set of coil segments 19 includes two coil segments 19U1 and 19U2 for the U phase, two coil segments 19V1 and 19V2 for the V phase, and two coil segments 19W1 and 19W2 for the W phase, for a total of six. The book is the minimum unit, and it is composed of 8 units. In one set arranged in a cylindrical shape, the straight portions 19a of the coil segments 19 are arranged in two rows in the radial direction. That is, a large number (48 × 2) of straight portions 19a are arranged in a cylindrical shape having two layers having different diameters. In this example, it is illustrated that three sets of coil segments 19 are prepared, but the present embodiment is not limited to the case where three sets of coil segments 19 are prepared.

FIG. 7 is an enlarged perspective view of the coil segment 19 in the region B of FIG.
As shown by a solid line in FIG. 7, the straight portion 19a of the coil segment 19 before bending is the extending end portion 19a1 which is bent and molded in the bending step described later and the end discarded in the cutting step described later. The material portion 19a3 is adjacent to each other via the extending end portion 19a1 and the low-rigidity portion 19a2 having a lower rigidity than the end material portion 19a3. That is, by forming a slit-shaped groove portion 19a4 extending from one side surface of the flat line portion toward the other side surface at the tip portion of the straight line portion 19a, the groove portion 19a4 and the other side surface are formed from the other region of the flat line portion. Also forms a low-rigidity portion 19a2 having a small cross-sectional area and reduced rigidity. The low-rigidity portion 19a2 is located in the straight line portion 19a between the extending end portion 19a1 and the end material portion 19a3 facing each other via the groove portion 19a4. The groove portion 19a4 is formed in a slit shape at the tip of the straight portion 19a. The groove portion 19a4 is inclined at an angle θ1 from the central axis C2 so as to intersect the central axis C2 of the straight line portion 19a. The groove portion 19a4 extends from one short side of the flat line to the vicinity of the other short side in the straight portion 19a composed of the flat line, and further opens on the long side side surface of the flat line.
As shown by the broken line in FIG. 7, when the extending end portion 19a1 is bent in the bending step, the inside of the groove portion 19a4 is exposed to the outside. A part of the exposed region of the groove portion 19a4 is used as the joining portion 19a5 in the joining step described later. As shown by the broken line in FIG. 7, the joint portion 19a5 is made substantially parallel to the other end surface 16b of the stator core 16 in the bending step. As shown by the broken line in FIG. 7, the low-rigidity portion 19a2 is cut in the cutting step, and the end material portion 19a3 is separated from the extending end portion 19a1.

FIG. 8 is a perspective view showing a stator core assembly in which the coil segment 19 is attached to the stator core 16 of FIG.
As shown in FIG. 8, each set of coil segments 19 is inserted into the slot 20 from the one end surface 16a side of the stator core 16. The straight portion 19a of the coil segment 19 is inserted into the slot 20 and protrudes from the other end surface 16b of the stator core 16 by a predetermined length to form the extending end portion 19a1. The 96 (48 × 2) straight lines 19a located at both ends of a set (48) of coil segments 19 arranged in a cylindrical shape correspond to two layers of cylinders in the corresponding 48 slots 20. Then, for example, it is inserted at the positions of the 6th layer (outermost layer) and the 5th layer. Three sets (144, 48 × 3) of coil segments 19 arranged in a cylindrical shape are inserted into the corresponding 48 slots 20 from the one end surface 16a side of the stator core 16. The straight portion 19a and the extending end portion 19a1 of the three sets of coil segments 19 are arranged in a concentric, six-layered cylindrical shape having different diameters. In each slot 20, the straight line portions 19a are arranged in a radial direction from the sixth layer (outermost layer) to the first layer (innermost layer).

FIG. 9 is a perspective view showing all the coil segments 19 mounted on the stator core 16 and changed in the vertical direction.
As shown in FIG. 9, the stator core 16 (stator core assembly) to which the coil segment 19 is mounted is oriented up and down due to bending molding of the extension end portion 19a1 of the coil segment 19 described later. Inverted.
Coil segment 19P located in the 6th layer (outermost layer), coil segment 19Q located in the 5th layer, coil segment 19R located in the 4th layer, coil segment 19S located in the 3rd layer, located in the 2nd layer The coil segment 19T and the straight portion 19a of the coil segment 19U located in the first layer (innermost layer) are lined up in a row in the radial direction of the stator core 16.

A bending step of bending the coil segment 19 mounted on the stator core 16 will be described with reference to FIGS. 10 to 16 and the like.
10 to 16 show the 48 coils of the 6th layer, which are the first of the bending steps of the 48

coil segments

19P, 19Q, 19R, 19S, 19T and 19U of the 6th to 1st layers. The bending process of the segment 19P is shown.
FIG. 10 shows a bending step (first time) of 48 coil segments 19P located in the sixth layer (outermost layer) of the coil segments 19 mounted on the stator core, and is performed by a bending jig 101. First (first time), a perspective view showing a state immediately before bending and molding the 48 coil segments 19P of the outermost layer, FIG. 11 is a perspective view showing an enlarged region C of FIG. 10, and FIG. 12 is a view. It is a side view which shows the area C of 10 enlarged.
With a folding jig, 48 coils of the same layer are arranged in the order of 48 coil segments 19P located in the 6th layer (outermost layer) to 48 coil segments 19U located in the 1st layer (innermost layer). The extending end portion 19a1 of the segment 19 is simultaneously bent and molded. Here, the 48

coil segments

19P, 19Q, 19R, 19S, 19T and 19U are arranged in a circular shape, but their diameters are different. That is, the diameter of the circular shape gradually decreases in the order of the 48 coil segments 19P located in the 6th layer (outermost layer) to the 48 coil segments 19U located in the 1st layer (innermost layer). Therefore, six types of bending jigs whose outer shape is gradually reduced are used in the order of 48

coil segments

19P, 19Q, 19R, 19S, 19T and 19U.
The bending jig 101 shown in FIG. 10 is used for bending molding of 48 coil segments 19P located in the sixth layer (outermost layer). As shown in FIGS. 11 and 12, the folding jig 101 is formed in a ring shape, and a concave mounting portion 101c is formed on the inner peripheral surface 101a. The mounting portion 101c is formed by notching the inner peripheral surface 101a from the lower end 101b of the bending jig 101 upward by a predetermined length. The mounting portions 101c are composed of 48 pieces as a set, and are formed at substantially equal intervals along the circumferential direction of the inner peripheral surface 101a. The folding jig 101 is made of a metal having sufficient rigidity. The folding jig 101 is supported by an elevating and rotating drive mechanism (not shown).
As shown in FIGS. 11 and 12, the straight portion 19Pa of the coil segment 19 projects upward from the other end surface 16b of the stator core 16 along the axial direction Z of the stator core 16. In the straight portion 19Pa, the groove portion 19Pa4 located between the extension end portion 19Pa1 and the end material portion 19Pa3 is inclined with respect to the axial direction Z of the stator core 16. The low-rigidity portion 19Pa2 is located between the extending end portion 19Pa1 and the end material portion 19Pa3 separated by the groove portion 19Pa4. The attachment portion 101c of the folding jig 101 is attached to the end material portion 19Pa3 located at the tip of the straight portion 19Pa. At this time, the lower end 101b of the bending jig 101 and the upper end of the groove portion 19Pa4 of the coil segment 19P are aligned along the circumferential direction of the stator core 16.

FIG. 13 is a perspective view showing a state immediately after bending and molding 48 coil segments 19P from the state of FIG. 10, FIG. 14 is a perspective view showing an enlarged region D of FIG. 13, and FIG. 15 is a view. It is a side view which shows the area D of 13 enlarged.
As shown in FIG. 13, the folding jig 101 moves to the stator core 16 side while rotating clockwise CW around the stator core 16 in the bending step. As a result, the extending end portion 19Pa1 of the 48 coil segments 19P is bent. As shown in FIGS. 14 and 15, the groove portion 19a4 of the coil segment 19 is exposed to the outside on the inside in the bending step. The joint portion 19Pa5 of the coil segment 19 is inclined from the other end surface 16b of the stator core 16 shown in FIG. 12 to a state substantially parallel to the other end surface 16b of the stator core 16 shown in FIG.

FIG. 16 is a side view showing bending molding of the coil segment 19.
As shown by the broken line in FIG. 16, before the coil segment 19 is bent and formed, in the straight portion 19a, the extending end portion 19a1 and the end material portion 19a3 pass through the low-rigidity portion 19a2 and the shaft of the stator core 16. Adjacent on the line. The low-rigidity portion 19a2 is located in the straight portion 19a between the extending end portion 19a1 and the end material portion 19a3 facing each other via the groove portion 19a4.
As shown by a solid line in FIG. 16, after the coil segment 19 is bent and molded, the extension end portion 19a1 is bent and the inside of the groove portion 19a4 is exposed to the outside. A part of the exposed region of the groove portion 19a4 is used as the joint portion 19a5. The joint portion 192a5 is substantially parallel to the other end surface 16b of the stator core 16.

A cutting step of cutting the end material portion 19a3 of the bent-formed coil segment 19 from the extension end portion 19a1 will be described with reference to FIG.
FIG. 17 is a perspective view showing a cutting process of the coil segment 19.
The cutting of the coil segment 19 is performed, for example, by cutting the low-rigidity portion 19a2 of the coil segment 19 by the laser beam L1. The laser light L1 emitted from the laser light source 102 irradiates the low-rigidity portion 19a2 of each coil segment 19P along the direction of the circumscribed circle of the concentric circles composed of the 48 coil segments 19P. In the 48 coil segments 19P, the low-rigidity portion 19a2 between the extending end portion 19a1 and the end material portion 19a3 is cut by the laser beam L1 in order along the circumferential direction of the stator core 16, and the extending end is extended. The portion 19a1 and the scrap portion 19a3 are separated. Each time the low-rigidity portion 19a2 of one coil segment 19P is cut by the laser beam L1, the stator core 16 is rotated clockwise by an angle of 1 slot 20 and the low-rigidity portion 19a2 of the next coil segment 19P is rotated. Is cut.
Here, in order to stably cut the low-rigidity portion 19a2 of the coil segment 19P, the low-rigidity portion 19a2 is irradiated with the laser beam L1 while the bending jig 101 is still attached to the end material portion 19a3. It may be configured to be cut. Further, in order to efficiently cut the low-rigidity portion 19a2, the laser beam L1 may be scanned along the radial direction of the stator core 16.
The coil segment 19 may be cut by using a mechanical cutter in addition to cutting by the laser beam L1.

After completing the bending and cutting steps of the 48 coil segments 19P located in the 6th layer, the 48

coil segments

19Q, 19R, 19S, 19T and 19U located in the 5th to 1st layers are folded. The bending step and the cutting step are performed in order. The extending ends 19a1 of the

coil segments

19P, 19Q, 19R, 19S, 19T and 19U are alternately bent and formed in opposite directions along the circumferential direction of the stator core 16. That is, the extending end portions 19a1 of the

coil segments

19P, 19R and 19T of the 6th layer, the 4th layer and the 2nd layer are clocked from the base end side to the tip end side along the circumferential direction of the stator core 16. It is bent and molded in the direction CW. On the other hand, the extending end portions 19a1 of the

coil segments

19Q, 19S and 19U of the fifth layer, the third layer and the first layer are counterclockwise from the proximal end side to the distal end side along the circumferential direction of the stator core 16. It is bent and molded in a clockwise CCW direction. The bending direction of the coil segment 19 is selected by changing the rotation direction of the bending jig.
18 and 19 show the 48 coils of the first layer, which are the last of the bending steps of the 48

coil segments

19P, 19Q, 19R, 19S, 19T and 19U of the 6th to 1st layers. The bending process of the segment 19U is shown.
FIG. 18 shows a bending step (sixth time) of 48 coil segments 19U located in the first layer (innermost layer) of the coil segments 19 mounted on the stator core, using the bending jig 103. A perspective view showing a state immediately before bending and molding the 48 coil segments 19U of the innermost layer at the end (sixth time), FIG. 19 shows immediately after bending and molding the 48 coil segments 19U from the state of FIG. It is a perspective view which shows the state.
The folding jig 103 moves to the stator core 16 side while rotating counterclockwise CCW around the central axis of the stator core 16 as shown in FIG. 19 from the state shown in FIG. .. As a result, the extending ends of the 48 coil segments 19U are bent, and the joints are substantially parallel to the other end surface 16b of the stator core 16.
In the embodiment, the folding jig 101 and the folding jig 103 are rotated around the central axis of the stator core 16, but the circumference of the bending jig 101 with respect to the central axis of the stator core 16 The relative position in the direction may change, and the stator core 16 may be rotated around the central axis of the folding jig 101 and the folding jig 103, or the stator core 16 and the folding jig 101 and The folding jig 103 and the folding jig 103 may be rotated in opposite directions.
Further, the extension end portions 19a1 of the

coil segments

19P, 19Q, 19R, 19S, 19T and 19U of the sixth to first layers may be bent at the same time. In the case of such a configuration, the six types of bending jigs for the

coil segments

19P, 19Q, 19R, 19S, 19T and 19U of the sixth layer to the first layer are respectively along the radial direction of the stator core 16. It has a penetrating mounting part. That is, by reducing the radial thickness of the bending jig to the same degree as the radial thickness of the coil segment 19P, for example, the folding jig for the fifth layer can be used for the sixth layer and the fourth layer. Do not interfere with the folding jig for. Three types of bending jigs for the 6th, 4th and 2nd

layer coil segments

19P, 19R and 19T, and the 5th, 3rd and 1st

layer coil segments

19Q, 19S and 19U. The three types of bending jigs have different rotation directions along the circumferential direction of the stator core 16.

After the coil segment 19 is bent as described above, the two joints 19a5 adjacent to each other in the radial direction are mechanically and electrically joined to each other to form a three-phase coil 18. FIG. 20 is a perspective view showing a joining process of the coil segment 19. The joining step of the coil segment 19 is performed, for example, by welding the coil segment 19 with the laser beam L2.
The laser light L2 is emitted from the laser light source 104, and the joint portion 19a5 of the coil segment 19 is irradiated with the laser light L2. The laser light source 104 is composed of, for example, a semiconductor laser and an optical fiber. Specifically, with the stator core 16 held at a predetermined position, the boundary between the sixth layer joint portion 19a5 and the fifth layer joint portion 19a5 arranged in a row in the radial direction, and the fourth layer joint. The boundary portion between the portion 19a5 and the joint portion 19a5 of the third layer and the boundary portion between the joint portion 19a5 of the second layer and the joint portion 19a5 of the first layer are irradiated with the laser beam L2, respectively. The laser light source 104 is moved to the vicinity of the joint portion 19a5 of the coil segment 19 by a robot hand, a drive stage, or the like. The two adjacent joints 19a5 are partially heated and melted by the laser beam L2, respectively, and then agglomerated weld beads 19d are formed in a fused state. The weld bead 19d mechanically and electrically joins two adjacent joints 19a5.

After welding a row of joints 19a5, rotate the stator core 16 in the circumferential direction by 7.5 degrees (360 degrees divided by 48) and then stop. In this state, at the boundary between the 6th and 5th row joints 19a5, the boundary between the 4th and 3rd row joints 19a5, and the boundary between the 2nd and 1st row joints 19a5. , Laser light L2 is irradiated respectively, and two adjacent joints 19a5 are welded to each other. By repeating such a joining process, two joining portions 19a5 in all rows arranged in the radial direction are welded. By welding and joining two joints 19a5 in each row, a three-phase (U-phase, V-phase, and W-phase) coil 18 composed of a plurality of coil segments 19 is formed. The bonding step is not limited to laser welding, and other bonding methods such as soldering and ultrasonic bonding may be used.

After the joining step is completed, the joint portion 19a5 of the coil segment 19 is powder-coated or covered with an insulating material such as varnish to ensure electrical insulation between the coils 18. Further, a U-phase connection terminal TU, a V-phase connection terminal TV, and a W-phase connection terminal TW are connected to each phase of the coil 18.
Through the above manufacturing process, the coil 18 is mounted and connected to the stator core 16 to form the stator 12.

According to the method for manufacturing the stator 12 according to the embodiment configured as described above, the extending end portion 19a1 of the coil segment 19 is placed between the low-rigidity portion 19a2 and the other end surface 16b side to the circumference of the stator core 16. After bending in the direction, the low-rigidity portion 19a2 is cut. By providing a low-rigidity portion 19a2 having a smaller cross-sectional area than other regions of the flat wire and bending the extending end portion 19a1 at the position of the low-rigidity portion 19a2, the extending end can be easily and with a small curvature. The portion 19a1 can be bent. That is, the extension end 19a1 is bent with a relatively small curvature by refracting the low-rigidity portion 19a2 connected to the tip gripped by the bending jig 101 without significantly bending the extension end 19a1. Can be bent. Therefore, the protruding height of the coil end 18b of the formed coil 18 (the protruding height from the other end surface 16b of the stator core 16) can be suppressed low. As a result, the coil 18 and the stator 12 can be miniaturized.
From the above, according to the embodiment, a method for manufacturing the stator 12 that can be miniaturized can be obtained.
Further, according to the manufacturing method of the embodiment, the extending end portion 19a1 is bent at the position of the low-rigidity portion 19a2 of the coil segment 19 in the direction in which the groove portion 19a4 opens. According to such a manufacturing method, when the extending end portion 19a1 is bent, the groove portion 19a4 can be deformed so as to open outward. Therefore, the extending end portion 19a1 is formed starting from the low rigidity portion 19a2. Easy to refract. Therefore, the extending end portion 19a1 can be easily bent at the position of the low-rigidity portion 19Xa2 with a small curvature.
Further, according to the manufacturing method of the embodiment, the low-rigidity portion 19a2 of the coil segment 19 is composed of a groove portion 19a4 provided in the straight line portion 19a. Therefore, an arbitrary low-rigidity portion 19a2 can be easily formed on the straight portion 19a of the coil segment 19. That is, the specifications of the low-rigidity portion 19a2 (high or low rigidity, etc.) can be easily set by the depth of cut and the angle of the groove portion 19a4 with respect to the straight portion 10a.
Further, according to the manufacturing method of the embodiment, the thickness of the connecting portion between the extending end portion 19a1 and the end material portion 19a3 is reduced by the groove portion 19a4. Therefore, it is easy to cut the end material portion 19a3 from the extending end portion 19a1 to remove the end material portion 19a3.
Further, according to the manufacturing method of the embodiment, while bending the extending end portion 19a1 in the circumferential direction of the stator core 16, a part of the inner surface of the groove portion 19a4 is made substantially parallel to the other end surface 16b side of the stator core 16. It is used as the joint portion 19a5. Therefore, it is easy to join the joint portions 19a5 adjacent to each other in the radial direction of the stator core 16.

Next, a modification 1 of the embodiment will be described with reference to FIG.
FIG. 21 is a side view showing bending molding of the coil segment 19X of the first modification of the embodiment.

In the straight portion 19Xa of the coil segment 19X of the modified example 1 of the embodiment, a rectangular (triangular) notch portion 19Xa4 is formed in place of the slit-shaped groove portion 19a4 described above. At the tip of the straight portion 19Xa, a notch portion 19Xa4 extending from one side surface of the flat conductor toward the other side surface is formed, and a low rigidity portion 19Xa2 is formed between the notch portion 19Xa4 and the other side surface.
As shown by the broken line in FIG. 21, before the bending molding of the coil segment 19X, the extension end portion 19Xa1 and the end material portion 19Xa3 are connected to the shaft of the stator core 16 via the low rigidity portion 19Xa2 in the straight portion 19Xa. Adjacent on the line. The low-rigidity portion 19Xa2 is located in the straight portion 19Xa between the extending end portion 19Xa1 and the end material portion 19Xa3 facing each other via the notch portion 19Xa4. In the coil segment 19X, the extending end portion 19Xa1 is bent in the direction in which the notched portion 19Xa4 opens at the position of the low-rigidity portion 19Xa2. The cutout portion 19Xa4 is located on the straight portion 19Xa on the front side in the bending direction of the extending end portion 19Xa1. The joint portion 19Xa5 has a triangular shape as an example, but may have a rectangular shape or a semicircular shape.
As shown by the solid line in FIG. 21, the extension end portion 19Xa1 is bent by the bending molding of the coil segment 19X, and the notch portion 19Xa4 is expanded from the inside to the outside and exposed. A part of the exposed region of the cutout portion 19Xa4 is used as the joint portion 19Xa5 after the low-rigidity portion 19Xa2 is cut.
In the straight portion 19Xa of the coil segment 19X, the low-rigidity portion 19Xa2 is cut, and the end material portion 19Xa3 is separated from the extending end portion 19Xa1.

According to the method for manufacturing the stator 12 according to the first modification of the embodiment configured as described above, the low-rigidity portion 19Xa2 of the coil segment 19X is composed of the notch portion 19Xa4 provided in the straight portion 19Xa. Therefore, an arbitrary low-rigidity portion 19Xa2 can be easily formed on the straight portion 19Xa of the coil segment 19X. That is, the specifications of the low-rigidity portion 19Xa2 (high or low rigidity, etc.) can be easily set by the notch amount of the notch portion 19Xa4 with respect to the straight portion 10a.
Further, in the coil segment 19X, the extending end portion 19Xa1 is bent at the position of the low-rigidity portion 19Xa2 in the direction in which the notched portion 19Xa4 opens. According to such a manufacturing method, when the extension end portion 19Xa1 is bent, the notch portion 19Xa4 can be deformed so as to open outward. Therefore, the extension end portion 19a1 starts from the low rigidity portion 19Xa2. Is easy to refract. Therefore, the extending end portion 19a1 can be easily bent at the position of the low-rigidity portion 19Xa2 with a small curvature.
Further, since the shape of the notch portion 19Xa4 can be easily recognized by an image using a CCD camera or the like or visually confirmed by an operator, the specifications of the low rigidity portion 19Xa2 (high or low rigidity) are used. Easy to maintain within a certain range.
Further, according to the manufacturing method of the embodiment, the connecting portion between the extending end portion 19Xa1 and the end material portion 19Xa3 is thinned by the notch portion 19Xa4. Therefore, it is easy to cut the end material portion 19Xa3 from the extending end portion 19Xa1 and remove the end material portion 19Xa3.

Next, a modification 2 of the embodiment will be described with reference to FIG.
FIG. 22 is a side view showing bending molding of the coil segment 19Y of the second modification of the embodiment.

In the straight portion 19Ya of the coil segment 19Y of the modified example 2 of the embodiment, instead of the slit-shaped groove portion 19a4 described above, a notched portion 19Ya4 formed of a step formed by a long and narrow tip is formed. ..
In the straight portion 19Ya, the width along the circumferential direction of the stator core 16 of the end material portion 19Ya3 is narrowed as compared with the width along the circumferential direction of the stator core 16 of the extending end portion 19Ya1, and the notch portion is formed. It constitutes 19Ya4. Specifically, at the tip of the straight portion 19Ya, a portion located on the front side in the bending direction in bending molding is vertically elongated and cut out. That is, the notch portion 19Ya4 is located on the straight portion 19Ya on the front side in the bending direction of the extending end portion 19Ya1.
As shown by the broken line in FIG. 22, before the coil segment 19Y is bent and formed, in the straight portion 19Ya, the extension end portion 19Ya1 and the end material portion 19Ya3 pass through the low rigidity portion 19Ya2 and the shaft of the stator core 16 Adjacent on the line. The low-rigidity portion 19Ya2 is located in the straight portion 19Ya between the extending end portion 19Ya1 and the end material portion 19Ya3 facing each other via the notch portion 19Ya4.
As shown by the solid line in FIG. 22, the extension end portion 19Ya1 is bent by the bending molding of the coil segment 19Y. The cutout portion 19Ya4 is used as the joint portion 19Ya5 after the low-rigidity portion 19Ya2 is cut (partially melted and cut).
In the straight portion 19Ya of the coil segment 19Y, the low-rigidity portion 19Ya2 is cut, and the end material portion 19Ya3 is separated from the extending end portion 19Ya1.

According to the method for manufacturing the stator 12 according to the modified example 2 of the embodiment configured as described above, similarly to the method for manufacturing the stator 12 according to the modified example 1 of the embodiment, therefore, the coil segment 19Y Any low-rigidity portion 19Ya2 can be easily formed on the straight portion 19Ya. That is, the specifications of the low-rigidity portion 19Ya2 (high or low rigidity, etc.) can be easily set by the size of the step shape (the shape notched in an elongated rectangular shape) of the notched portion 19Ya4 with respect to the straight portion 10a.

Next, a modification 3 of the embodiment will be described with reference to FIG. 23.
FIG. 23 is a side view showing bending molding of the coil segment 19Z of the modification 3 of the embodiment.

Unlike the coil segment 19Y of the modification 2 of the embodiment, the straight portion 19Z of the coil segment 19Z of the modification 3 of the embodiment has a portion located on the rear side in the bending direction in the bending molding, which is vertically elongated. Missing. That is, the notch portion 19Za4 is located in the straight portion 19Za on the rear side in the bending direction of the extending end portion 19Za1.
As shown by a broken line in FIG. 23, before bending and forming the coil segment 19Z, in the straight portion 19Za, the extension end portion 19Za1 and the end material portion 19Za3 pass through the low rigidity portion 19Za2 and the shaft of the stator core 16. Adjacent on the line. The low-rigidity portion 19Za2 is located in the straight portion 19Za between the extending end portion 19Za1 and the end material portion 19Za3 facing each other via the notch portion 19Za4.
As shown by the solid line in FIG. 23, the extension end portion 19Za1 is bent by the bending molding of the coil segment 19Z. The cutout portion 19Za4 is used as the joint portion 19Za5 after the low-rigidity portion 19Za2 is cut.
In the straight portion 19Za of the coil segment 19Z, the low-rigidity portion 19Za2 is cut, and the end material portion 19Za3 is separated from the extending end portion 19Za1.

According to the method for manufacturing the stator 12 according to the modified example 3 of the embodiment configured as described above, similarly to the method for manufacturing the stator 12 according to the modified example 2 of the embodiment, therefore, the coil segment 19Z Any low-rigidity portion 19Za2 can be easily formed on the straight portion 19Za. That is, the specifications of the low-rigidity portion 19Za2 (high or low rigidity, etc.) can be easily set by the size of the step shape (the shape notched in an elongated rectangular shape) of the notched portion 19Za4 with respect to the straight portion 10a.
Further, when the extension end portion 19Za1 is bent, the low-rigidity portion 19Za2 is likely to be sandwiched between the extension end portion 19Za1 and the end material portion 19Za3. Therefore, for example, the low-rigidity portion 19Za2 is cut so as to be substantially parallel to the other end surface 16b of the stator core 16, and the joint portion 19Za5 can be easily formed into an arbitrary shape.

Although the embodiment of the present invention has been described, this embodiment is presented as an example and is not intended to limit the scope of the invention. The embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.
For example, the number of coil turns and the number of coil segments installed are not limited to the above-described embodiments, and can be increased or decreased as appropriate. For example, it may be configured so that four or eight segment straight portions are arranged in one slot. The dimensions, materials, shapes, and the like of the rotor are not limited to the above-described embodiments, and can be variously changed according to the design. The rotor and the rotary electric machine according to the embodiment can be applied not only to a permanent magnet field electric motor but also to an induction motor.

10 ... rotary electric machine, 12 ... stator, 16 ... stator core, 16a ... one end surface, 16b ... other end surface,
18 ... Coil, 18a, 18b ... Coil end,
19, 19P, 19Q, 19R, 19S, 19T, 19U, 19X, 19Y, 19Z ... Coil segment,
19a, 19Pa, 19Xa, 19Ya, 19Za ... Straight line part,
19a1,19Pa1,19Xa1,19Ya1,19Za1 ... Extension end,
19a2, 19Pa2, 19Xa2, 19Ya2, 19Za2 ... Low rigidity part,
19a3, 19Pa3, 19Xa3, 19Ya3, 19Za3 ...
19a4, 19Pa4 ... Groove, 19Xa4, 19Ya4, 19Za4 ... Notch,
19a5,19Pa5,19Xa5,19Ya5,19Za5 ... Joint,
19b ... Cross-linked part, 19c ... Insulation coating, 19d ... Welded bead, 20 ... Slot,
101, 103 ... Bending jig

Claims

It is formed by bending a flat conductor and has a pair of straight portions facing each other and a cross-linked portion connecting one ends of the pair of straight portions, each of the straight portions having another region of the flat conductor at the tip portion. Prepare a plurality of coil segments having a low-rigidity portion having a smaller cross-sectional area and lower rigidity.
The straight portions of the plurality of coil segments are inserted into a plurality of slots from one end surface side of the stator core, and a plurality of extending ends protruding from the other end surface side of the stator core in a predetermined length axial direction are formed. By constructing and arranging the plurality of the straight portions side by side in the radial direction in each slot, the plurality of the extending end portions are arranged in a cylindrical shape of a plurality of layers coaxial with the stator core.
With the tip of the straight portion gripped by the folding jig, at least one of the bending jig and the stator core is relatively rotated in the circumferential direction of the stator core to extend the rod. The end portion is bent in the circumferential direction of the stator core between the low rigidity portion and the other end surface side.
The low-rigidity portion is cut to form a joint portion,
A method for manufacturing a stator, in which the joint portions adjacent to each other in the radial direction of the stator core are joined to each other.
A claim for forming a slit-shaped groove extending from one side surface of the flat conductor toward the other side surface at the tip end portion of the straight line portion, and forming the low rigidity portion between the end of the groove portion and the other side surface. Item 2. The method for manufacturing a stator according to item 1.
The method for manufacturing a stator according to claim 2, wherein the extending end portion is bent at the position of the low rigidity portion in the direction in which the groove portion opens.
The first aspect of the present invention, wherein a notch extending from one side surface of the flat conductor toward the other side surface is formed at the tip end portion of the straight line portion, and the low rigidity portion is formed between the notch portion and the other side surface. The method for manufacturing the stator described.
The method for manufacturing a stator according to claim 4, wherein the extending end portion is bent at the position of the low rigidity portion in a direction in which the notch portion opens.