JP6186745B2 - Stator core manufacturing method - Google Patents

Description

The present invention relates to a method for manufacturing a stator core used in a rotating electrical machine.

  2. Description of the Related Art A stator core is known that includes a laminated body of annular core sheets formed by bending a belt-shaped core sheet into an annular shape. For example, Patent Document 1 describes a belt-like core sheet in which core pieces having a tooth portion are connected in a straight line via a connecting portion. A pair of claw portions are provided on both sides of the teeth portion of the belt-shaped core sheet. The claw portion is bent into a ring-shaped core sheet by bending the belt-shaped core sheet into an annular core sheet, and then bent at a connection point with the tooth portion to form a flange portion at the tip of the teeth portion of the stator core.

JP 2009-261218 A

  By the way, in the punching process of the strip-shaped core sheet, it is required to improve the yield of the plate material as a material. Then, when punching out two strip | belt-shaped core sheets, it is possible to plate up so that the teeth part of a 2nd strip | belt-shaped core sheet may be located between the adjacent teeth parts of a 1st strip | belt-shaped core sheet. However, when the claw portions are provided on both sides of the tooth portion as in the configuration of Patent Document 1, the gap between the adjacent tooth portions of the belt-like core sheet is narrowed, so that the adjacent tooth portions of the belt-like core sheet are taken during plate cutting. There is a problem that it is not possible to dispose another tooth portion of the belt-shaped core sheet.

  In order to solve the above problem, it is conceivable to provide a pair of claw portions at the tip of the tooth portion so that the claw portion does not narrow the gap between adjacent tooth portions. As a method of bending the claw portion, for example, a method of pushing a punch disposed on the side opposite to the teeth portion with respect to the claw portion into the claw portion side can be considered. However, if the claw portion is bent as described above, excessive stress acts on the tip of the claw due to the punch contacting only the tip of the claw, and the tip of the claw may be deformed.

The present invention has been made in view of the above-mentioned points, and the object thereof is to improve the yield of a plate material for punching a belt-like core sheet, and when the claw part of the core piece is bent, the tip part of the claw part It is providing the manufacturing method of the stator core which can suppress a deformation | transformation of this.

This onset Ming is composed of strip-shaped core sheet comprising a plurality of core pieces that led straight through the connecting portion bendable laminate of annular core sheets formed by bending the annular used rotary electric machine It is a manufacturing method of a stator core . The core piece of the belt-like core sheet has a yoke part connected to the connection part, a tooth part extending from the yoke part, and a claw part protruding from the tip of the tooth part in the same direction as the extending direction of the tooth part. The claw portion is disposed between the tip of the teeth portion and the claw portion, and when the punch that contacts at least the root of the claw portion rotates around the rotation axis passing through the punch, the claw portion may fall from the root by the punch. To be bent.

Therefore, a tooth part of another belt-like core sheet can be arranged between the tooth parts of the belt-like core sheet when cutting the plate without narrowing the gap between the tooth parts of the belt-like core sheet. Therefore, according to this invention, the yield of the board | plate material which punches a strip | belt-shaped core sheet | seat can be improved.
Further, in the present invention, since the punch contacts at least the base of the nail part, it is possible to suppress excessive stress from acting on the tip of the nail part compared to the case where the punch contacts only the tip of the nail part. it can. Therefore, according to this invention, when bending the nail | claw part of a core piece, a deformation | transformation of the front-end | tip part of the said nail | claw part can be suppressed.

It is a front view of the alternating current generator as a rotary electric machine by 1st Embodiment of this invention. It is sectional drawing of the alternating current generator of FIG. It is a front view of the stator core Assy of FIG. It is the IV-IV sectional view taken on the line of FIG. FIG. 4 is a front view of the stator core of FIG. 3. It is a front view of the strip | belt-shaped core sheet | seat which is a raw material of the stator core of FIG. It is a figure which shows plate cutting when the strip | belt-shaped core sheet | seat of FIG. 6 is punched out from an electromagnetic steel plate. It is an enlarged view of the arrow VIII part of FIG. It is an enlarged view of the arrow IX part of FIG. It is an enlarged view of the arrow X part of FIG. It is a figure which shows the core sheet at the time of completion | finish of the 1st step of a bending process. It is a figure which shows the core sheet at the time of completion | finish of the 2nd step of a bending process. It is a figure which shows the core sheet at the time of completion | finish of the 3rd step of a bending process. It is an enlarged view of the arrow XIV part of FIG. It is an enlarged view of the connection part of the annular core sheet at the end of the connection process. It is the XVI-XVI sectional view taken on the line of FIG. 14, Comprising: It is a longitudinal cross-sectional view of the expansion jig used at a connection process. It is the XVII-XVII sectional view taken on the line of FIG. It is the XVIII-XVIII sectional view taken on the line of FIG. It is the XIX-XIX sectional view taken on the line of FIG. It is a figure which shows the place where the expansion jig | tool of FIG. 16 was inserted by the through-hole of the connection convex part to the intermediate part of the insertion part. It is a figure which shows the place where the expansion jig | tool of FIG. 16 was inserted by the through-hole of the connection convex part to the base end part of the insertion part. It is a figure which shows the cyclic | annular core sheet | seat set to the nail fall apparatus by the nail fall process. It is an enlarged view of the arrow XXIII part of FIG. It is a figure which shows the place where the 1st nail | claw part was bent from the state of FIG. It is a figure which shows the place where the 2nd nail | claw part was bent from the state of FIG. It is a figure which shows the cyclic | annular core sheet completed through all the manufacturing processes. It is a figure which shows the core sheet bending apparatus used at a bending process. It is the XXVIII-XXVIII sectional view taken on the line of FIG. It is a figure which shows the place where the strip | belt-shaped core sheet was set to the core sheet bending apparatus of FIG. It is an enlarged view of the arrow XXX part of FIG. It is the figure which looked at the base and slider of FIG. 30 in the arrow XXXI direction. It is a figure which shows the place which the slider of FIG. 30 slid with respect to the base. It is the figure which looked at the base and slider of FIG. 32 in the direction of arrow XXXIII. It is a figure which shows the place where all the connection parts of the strip | belt-shaped core sheet were bent by operating the base of the core sheet bending apparatus of FIG. It is a figure which shows the place where all the sliders of the core sheet bending apparatus of FIG. 34 were slid simultaneously with respect to the base. It is an enlarged view of the 1st nail | claw part and 2nd nail | claw part in the cyclic | annular core sheet | seat which comprises the stator core by 2nd Embodiment of this invention just before a nail | claw fall process. It is a figure which shows the place where the 1st nail | claw part and the 2nd nail | claw part were bent from the state of FIG. It is an enlarged view of the 1st nail | claw part and the 2nd nail | claw part in the cyclic | annular core sheet | seat which comprises the stator core by 3rd Embodiment of this invention just before a nail | claw fall process. It is a figure which shows the place where the 1st nail | claw part and the 2nd nail | claw part were bent from the state of FIG.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In the embodiments, substantially the same components are denoted by the same reference numerals and description thereof is omitted.
(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. The AC generator as a “rotating electric machine” to which the stator core according to the first embodiment is applied is mounted on a two-wheeled vehicle, and is used for charging a battery, supplying power to a spark plug and a lamp, and the like.

As shown in FIGS. 1 and 2, the AC generator 10 is an outer rotor type rotating electrical machine, and includes a stator 11, a rotor 12, and a position sensor 13. The stator 11 is attached to the engine cover 15 by mounting bolts 14. The stator 11 includes a stator core Assy 16, an insulator 17, and a coil 18. In the present embodiment, twelve coils 18 are arranged radially from the center of the stator 11.
The wiring to the coil 18 is electrically connected to the connector 21 via the cable 19. A signal line from the position sensor 13 is also connected to the connector 21.

The rotor 12 includes a rotor body 22 and a rotor base 28.
The rotor body 22 has a cup shape including a cylindrical portion 23 and a bottom portion 24, and the cylindrical portion 23 is located on the radially outer side of the stator 11. On the inner wall of the cylindrical portion 23, first magnets 25 having a radially inner polarity of N poles and second magnets 26 having a radially inner polarity of S poles are alternately attached in the circumferential direction. In addition, a position detection unit 27 is provided on the outer wall of the cylindrical unit 23, and the rotation state of the rotor 12 can be detected by the position sensor 13 detecting the position detection unit 27.

The rotor base 28 is fixed to the bottom 24 of the rotor body 22, and an attachment hole 29 and a key groove 31 are formed at the center. When the crankshaft 32 of the engine is directly connected to the mounting hole 29 and the key groove 31, the rotor 12 rotates integrally with the crankshaft 32.
When the rotor 12 rotates, the magnetic field around the coil 18 continuously changes, and an induced current is generated in the coil 18 due to the change in the magnetic field. This induced current is output as a single-phase, three-phase, etc. alternating current by the wiring of the coil 18.

Next, a detailed configuration of the stator 11 will be described with reference to FIGS.
As shown in FIGS. 3 and 4, the stator core Assy 16 has a stator core 40 and a pair of upper cores 41 provided on both sides of the stator core 40 in the thickness direction. The stator core 40 and the upper core 41 are integrally fixed by a rivet 42. The upper core 41 substantially coincides with the stator core 40 in a planar shape and a corresponding hole position. Further, the outer edge portion 43 of the upper core 41 is bent to the opposite side of the stator core 40 in the axial direction, and regulates the radial position of the insulator 17.

  The stator core Assy 16 forms an annular yoke 44, a plurality of teeth 45 extending radially from the yoke 44, and a plurality of flanges 46 projecting from both ends of the teeth 45 in the circumferential direction. The yoke 44 has holes such as a through hole 47 through which the mounting bolt 14 is passed, a terminal hole 48 through which a terminal for wiring is passed, and a rivet hole 49 through which the rivet 42 is passed. A coil 18 is wound around the tooth 45 via an insulator 17. The flange 46 regulates the winding range of the coil 18.

The stator core 40 is composed of a laminated body of annular core sheets 50 shown in FIG.
The annular core sheet 50 is formed by bending a band-shaped core sheet, which will be described later, into an annular shape, and includes a plurality of yoke parts 51, a plurality of connection parts 52, a plurality of teeth parts 53, and a plurality of claw parts 54, 55. doing. Each yoke part 51 is connected to the circumferential direction via the connection part 52. The connecting portion 52 has a smaller radial width than the yoke portion 51 and can be bent, and connects the radially outer sides of the yoke portions 51 adjacent in the circumferential direction. A slit 56 is formed between the yoke portions 51 that are radially inward of the connecting portion 52 and adjacent in the circumferential direction. A stress relief hole 57 is formed at the tip of the slit 56 to avoid stress concentration when the connecting portion 52 is bent.

  The teeth part 53 extends radially outward from the yoke part 51. The width | variety of the teeth part 53 is continuously large from the base end to the front-end | tip. At the tip of the tooth portion 53, two claw portions, that is, a first claw portion 54 and a second claw portion 55 are provided. The 1st nail | claw part 54 and the 2nd nail | claw part 55 are protrusions which protrude from the front-end | tip of the teeth part 53 to one side and the other of the circumferential direction.

  A recess 58 is formed at the center of the tip of the tooth portion 53. Further, a streak 59 is formed at a corner portion between the first claw portion 54 and the second claw portion 55 and the side surface of the teeth portion 53. These dents 58 and streaks 59 are remnants of a relief shape for avoiding stress concentration when the first claw portion 54 and the second claw portion 55 are bent during the manufacture.

Next, a method for manufacturing the stator core 40 will be described with reference to FIGS. The stator core 40 is manufactured through a punching process, a bending process, a connecting process, and a claw-falling process.
[Punching process]
First, in the punching process, the strip-shaped core sheet 60 shown in FIG. 6 is punched from the electromagnetic steel sheet. The strip-shaped core sheet 60 is composed of a plurality of core pieces 61 connected in a straight line via bendable connecting portions 52. The core piece 61 has the same yoke portion 51 connected to the connecting portion 52, a tooth portion 53 extending from the yoke portion 51 in the width direction of the belt-like core sheet 60, and the extending direction of the tooth portion 53 from the tip of the tooth portion 53. A first claw portion 54 and a second claw portion 55 projecting in the direction.

  In the present embodiment, as shown in FIG. 7, when the two strip-shaped core sheets 60 are punched from the electromagnetic steel sheet 62, the teeth of the second strip-shaped core sheet 60 are interposed between the adjacent tooth portions 53 of the first strip-shaped core sheet 60. The plate is cut so that the portion 53 is positioned.

  As shown in FIG. 8, a V-shaped notch 63 is formed between adjacent yoke portions 51. A stress relief hole 57 extending along the connecting portion 52 is formed at the tip of the notch 63. One of the two sides defining the notch 63 is a first side 64, the other is a second side 65, a first imaginary straight line 66 along the first side 64, and a second imaginary straight line 67 along the second side 65, Is the virtual intersection 68, the virtual intersection 68 is located in the connection portion 52.

  As shown in FIG. 9 and FIG. 10, the first end 69 which is one end of the strip-shaped core sheet 60 is formed with a connecting recess 71 whose opening is constricted, and the strip-shaped core sheet 60. A connecting convex portion 73 that can be inserted into the connecting concave portion 71 is formed on the second end portion 72 that is the other end portion.

The inner wall of the connecting recess 71 has a pair of tapered surfaces 78 that face each other in the width direction. In addition, a guide convex portion 84 protruding from the end face 83 of the first end portion 69 is formed in both the width direction with respect to the connecting concave portion 71. The guide convex portion 84 constitutes a guide concave / convex portion that guides insertion of the connecting convex portion 73 into the connecting concave portion 71 together with a guide concave portion 82 described later.
The connection convex part 73 has a through-hole 77 that penetrates in the thickness direction. In the present embodiment, the through-hole 77 is circular. This through-hole 77 is used for deforming the connecting projection 73 in the width direction in a connecting step described later. In addition, a guide recess 82 that is recessed from the end surface 81 of the second end 72 is formed in both the width direction with respect to the connection protrusion 73.

[Bending process]
In the bending process, the belt-like core sheet 60 of FIG. 6 is bent into an annular shape through three stages, and the annular core sheet 50 of FIG. 13 is formed. This will be described in detail below. In the present embodiment, a manufacturing method is adopted in which a plurality of strip-shaped core sheets 60 are laminated and then bent into an annular shape.

  First, in the first stage, as shown in FIG. 11, the other connecting portions 52 are bent leaving the central connecting portion 52 a located at the center in the longitudinal direction of the strip-shaped core sheet 60. When the connecting portion 52 is bent, the connecting portion 52 is bent around the bending center 75 located on the notch 63 side with respect to the connecting portion 52 as shown in FIG. Thereby, the connection part 52 is all pulled in the circumferential direction in the width direction. Further, the connecting portion 52 is bent around the bending center 75 by the same angle as the opening angle θ of the notch 63. Therefore, the bending is finished before the first side 64 and the second side 65 come into contact with each other.

  Subsequently, in the second stage, the central connection portion 52a is bent as shown in FIG. The pair of core pieces 61 connected to the connection portions 52 that have been bent are restrained so as not to move relative to each other until the second stage is completed, that is, until the bending of all the connection portions 52 is completed. At the stage where all the connection parts 52 have been bent, gaps 76 extending radially are formed between the yoke parts 51.

  Subsequently, in the third stage, the restraint between the pair of core pieces 61 connected to the bent connection portions 52 is released. At this time, since all of the width direction was pulled in the circumferential direction when bending, the connection portion 52 is deformed so as to be contracted in the circumferential direction by the spring back. Since the return at this time acts to close the gap 76, the annular core sheet 50 without the gap 76 is formed as shown in FIG.

[Connection process]
In the connecting step, as shown in FIG. 14, the connecting convex portion 73 inserted into the connecting concave portion 71 at the stage where the bending step is finished is prevented from coming off from the connecting concave portion 71, whereby the first end 69 of the annular core sheet 50. Are connected to the second end 72. This will be described in detail below.

  As shown in FIG. 15, the connecting protrusion 73 is expanded in the width direction by the through-hole 77 being expanded so that the maximum width of the connecting protrusion 73 is larger than the opening width of the opening 74 of the connecting recess 71. By being deformed, it is prevented from coming off from the connecting recess 71. The deformation in the width direction of the connecting convex portion 73 is performed using the extension jig 100 shown in FIGS.

  The extension jig 100 includes a pressing portion 101 and a rod-shaped insertion portion 102 extending from the pressing portion 101. The insertion portion 102 forms a pair of arc surfaces 103 and 104 and planes 105 and 106 that connect the arc surfaces 103 and the ends of the arc surface 104 to each other. The corners of the arc surface 103 and the arc surface 104 and the plane 105 and the plane 106 are rounded. The plane 105 and the plane 106 are parallel to each other. The width between the flat surface 105 and the flat surface 106, that is, the two-surface width X1, is substantially the same as the width X2 in the lateral direction of the deformed through-hole 77 shown in FIG.

  The insertion portion 102 is formed so that the maximum width continuously increases from the distal end portion 107 through the intermediate portion 108 to the proximal end portion 109. The arc surfaces 103a and 104a of the distal end portion 107 of the insertion portion 102 have a shape along the edge of the circular through hole 77 before deformation shown in FIG. That is, the maximum width Y1 of the tip portion 107 is substantially the same as the diameter D of the through hole 77 before deformation. The circular arc surfaces 103c and 104c of the base end portion 109 of the insertion portion 102 have a shape along the inner wall facing the longitudinal direction in the through-hole 77 after deformation shown in FIG. That is, the maximum width Y3 of the base end portion 109 is substantially the same as the width Y4 in the longitudinal direction of the through-hole 77 after deformation. The maximum width Y2 of the intermediate portion 108 of the insertion portion 102 is larger than the maximum width Y1 of the distal end portion 107 and smaller than the maximum width Y3 of the proximal end portion 109.

  As shown in FIGS. 16, 20, and 21 in order, the expansion jig 100 is configured such that the insertion portion 102 is inserted into the through-hole 77, so that the through-hole 77 is expanded in the width direction, and the connecting convex portion 73 is expanded in the width direction. Deform to spread. The connecting convex part 73 is brought into close contact with and fixed to the tapered surface 78 of the connecting concave part 71 by being deformed as described above. Thereby, the connection convex part 73 surface-contacts with the taper surface 78 of the connection recessed part 71, and a reliable connection force can be obtained.

  As shown in FIG. 15, a guide concavo-convex portion 79 is provided in both the width direction with respect to the connection concave portion 71 and the connection convex portion 73. The guide concavo-convex portion 79 has a guide convex portion 84 protruding from the end surface 83 of the first end portion 69 at a position adjacent to the connecting concave portion 71 in the width direction, and a second end at a position adjacent to the connecting convex portion 73 in the width direction. And a guide recess 82 that is recessed from the end surface 81 of the portion 72. The guide concavo-convex portion 79 functions as a guide means for guiding the insertion of the connection convex portion 73 into the connection concave portion 71.

[Nail pulling process]
In the claw-falling step, the first claw portion 54 and the second claw portion 55 of the annular core sheet 50 are fallen from the root so as to extend in one and the other in the circumferential direction. This will be described in detail below.
First, as shown in FIG. 22, the annular core sheet 50 that has finished the connecting step is set in the claw-falling device 85. The claw tilting device 85 includes a holding base 86 and a punch 87. The holding stand 86 includes a receiving member 88 that can support the tooth portion 53 from both sides in the width direction.

  At this stage, as shown in FIG. 23, the corners 92 of the first claw portion 54 and the second claw portion 55 of the annular core sheet 50 and the tip 91 of the teeth portion 53 are rounded. A depression 94 is formed at the corner between the first claw portion 54 and the second claw portion 55 and the side surface 93 of the teeth portion 53. The shape of the tip portion of the punch 87 is the same shape as the space defined between the first claw portion 54 and the second claw portion 55 of the annular core sheet 50. That is, when the punch 87 is inserted between the first claw portion 54 and the second claw portion 55, the punch 87 abuts along the first claw portion 54, the second claw portion 55, and the teeth portion 53.

After the annular core sheet 50 is set on the claw tilting device 85, as shown in FIG. 24, the punch 87 is rotated around the rotation axis 89 that coincides with the center of curvature of the corner 92, and the first claw portion 54 is rotated. Is bent so as to fall from the root 95. At this time, the punch 87 bends the first claw 54 while continuously contacting from the root 95 to the end 96 of the first claw 54, and is a receiving member disposed on both sides of the teeth 53 in the width direction. 1st nail | claw part 54 is inserted | pinched between 88. Further, the portion near the recess 94 in the root 95 of the first claw portion 54 is compressed, and the excess meat escapes into the recess 94, thereby forming the muscle 59.
Thereafter, similarly to the first claw portion 54, the second claw portion 55 is bent so as to fall from the root 95 as shown in FIG. 25, and the laminated body of the annular core sheet 50 shown in FIG. 26 is completed.

  The first claw portion 54 and the second claw portion 55 after being bent are located on the outermost side in the radial direction of the annular core sheet 50, and when incorporated into the AC generator 10 as shown in FIG. 12 is formed. As shown in FIG. 26, the radially outer surfaces 97 of the first claw portion 54 and the second claw portion 55 are arcuate surfaces that coincide with a virtual circle C concentric with the central hole 98 of the annular core sheet 50. In the present embodiment, as shown in FIG. 23, the first claw portion 54 and the second claw portion 55 are opposed to the punch 87 in a stage before the first claw portion 54 and the second claw portion 55 are bent. The surface 99 is formed as an arc-shaped surface corresponding to the virtual circle C.

Next, the core sheet bending apparatus used in the bending process will be described with reference to FIGS.
The core sheet bending apparatus 110 includes a plurality of sliders 111, a base 112, and a rotating shaft 113. As shown in FIGS. 28 to 30, the slider 111 is a holding member that can hold the core piece 61, and has a groove 114 into which the core piece 61 is fitted. The inner wall 115 of the groove 114 can support the yoke portion 51, and the inner walls 116 and 117 of the groove 104 can be supported so as to sandwich the tooth portion 53.
The slider 111 is attached to the base 112. Each base 112 is connected via a rotation shaft 113, and one of the adjacent bases 112 can be relatively rotated around the axis of the rotation shaft 113 with respect to the other.

  As shown by an arrow S in FIGS. 30 to 33, the slider 111 is slidable in the extending direction of the tooth portion 53 of the gripped core piece 61 with respect to the base 112. Specifically, as shown in FIG. 32, the slider 111 is gripped from the first state in which the bending center 75 of the gripped core piece 61 coincides with the axis 118 of the rotating shaft 113 as shown in FIG. The virtual intersection point 68 of the core piece 61 can be moved relative to the base 112 until the second state where the virtual intersection point 68 coincides with the axis 118 of the rotating shaft 113.

  In the core sheet bending apparatus 110, the band-shaped core sheet 60 is set as shown in FIG. 29 before the first stage of the bending process, and each base 112 is operated in the first stage and the second stage, whereby FIG. As shown in FIG. 35, after all the connecting portions 52 are bent, all the sliders 111 are simultaneously slid with respect to the base 112 to allow spring back of the connecting portions 52, and the annular core sheet 50 is formed as shown in FIG. .

  As described above, in the first embodiment, the core piece 61 of the strip-shaped core sheet 60 has the first claw portion 54 and the second claw portion that protrude from the tip of the tooth portion 53 in the same direction as the extending direction of the tooth portion 53. 55. The first claw portion 54 and the second claw portion 55 are moved by the punch 87 when the punch 87 that contacts at least the root 95 of the claw portions 54 and 55 rotates around the rotation axis 89 passing through the punch 87. It is bent so as to fall from the root 95.

  Therefore, the claw portions 54 and 55 do not narrow the gap between the tooth portions 53 of the band-shaped core sheet 60, and the tooth portions 53 of another band-shaped core sheet 60 are arranged between the teeth portions 53 of the band-shaped core sheet 60 during plate cutting. be able to. Therefore, according to 1st Embodiment, the yield of the board | plate material which pierces the strip | belt-shaped core sheet 60 can be improved.

  Further, since the punch 87 contacts at least the base 95 of the claw portions 54 and 55, an excessive stress acts on the tips of the claw portions 54 and 55 as compared with the case where the punch contacts only the tips of the claw portions. Can be suppressed. Therefore, according to 1st Embodiment, when bending the 1st nail | claw part 54 and the 2nd nail | claw part 55, a deformation | transformation of the front-end | tip part of the said nail | claw parts 54 and 55 can be suppressed.

  In the first embodiment, the punch 87 bends the claw portions 54 and 55 while continuously contacting from the root 95 to the end portion 96 of the claw portions 54 and 55. Therefore, the nail | claw parts 54 and 55 can be bent from the root 95, maintaining the shape before bending.

  In the first embodiment, the corner 92 between the claw portions 54 and 55 and the tip 91 of the teeth portion 53 is rounded, and the center of curvature of the corner 92 coincides with the rotation center 89 of the punch 87. Therefore, the claw portions 54 and 55 can be bent while the punch 87 is brought into contact with the roots 95 of the claw portions 54 and 55 as much as possible.

  Moreover, in 1st Embodiment, the opposition surface 99 which opposes the punch 87 just before the said nail | claw parts 54 and 55 bend is the annular core sheet after the nail | claw parts 54 and 55 are bent. The arcuate surface coincides with a virtual circle C concentric with the 50 central holes 98. Therefore, the interval between the stator 40 and the rotor 12 incorporated in the AC generator 10 can be kept constant in the circumferential direction.

  In the first embodiment, the opposing surface 99 of the claw portions 54 and 55 is formed into an arcuate surface that coincides with the virtual circle C when the punch 87 sandwiches the claw portions 54 and 55 between the receiving member 88 and the punch 87. Is done. Therefore, even if the facing surface 99 is deformed while the claw portions 54 and 55 are bent, the facing surface 99 can be corrected so as to coincide with the virtual circle C in the final bending stage.

(Second Embodiment)
An annular core sheet constituting the stator core according to the second embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 36, the roots 95 of the first claw part 54 and the second claw part 55 immediately before the nail collapse process have three recesses 94. Therefore, when the first claw portion 54 and the second claw portion 55 are bent from the root 95 as shown in FIG. 37 in the claw-falling step, the stress is further prevented from concentrating at one place on the edge of the root 95. Can do.

(Third embodiment)
An annular core sheet constituting a stator core according to a third embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 38, the roots 95 of the first claw part 54 and the second claw part 55 immediately before the claw-falling process have four recesses 94. Therefore, when the first claw portion 54 and the second claw portion 55 are bent from the root 95 as shown in FIG. 39 in the claw-falling step, the stress is further prevented from being concentrated at one place on the edge of the root 95. be able to.

(Other embodiments)
In another embodiment of the present invention, a single belt-like core sheet may be laminated after being bent into an annular shape.
In another embodiment of the present invention, the belt-like core sheet may be punched from a plate material other than the electromagnetic steel plate.
In another embodiment of the present invention, the first claw and the second claw need only be bent by a punch that contacts at least the root. For example, the first claw portion and the second claw portion may be bent by a punch that is not in contact with the end portion. In this case, when a relatively long claw part is bent, it is possible to reliably avoid stress from acting on the end part of the claw part.
In another embodiment of the present invention, the stator core can be applied not only to an AC generator for a motorcycle but also to an electric generator such as a generator for various uses or a brushless motor.
The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 10 ... Rotary electric machine 40 ... Stator core 50 ... Annular core sheet 51 ... Yoke part 52 ... Connection part 53 ... Teeth part 54 ... 1st nail | claw part 55 ... 2nd Claw part 60 ... strip-shaped core sheet 61 ... core piece 87 ... punch 89 ... rotation axis 91 ... tip 95 ... root

Claims (6)

Constructed from a laminate of annular core sheets (50) formed by annularly bending a strip-shaped core sheet (60) composed of a plurality of core pieces (61) connected in a straight line via a bendable connection (52) is a method of manufacturing a stator core used in the rotating electric machine (10) (40),
The core piece of the belt-shaped core sheet includes a yoke part (51) connected to the connection part, a tooth part (53) extending from the yoke part, and an extension of the tooth part from the tip (91) of the tooth part. Claw portions (54, 55) protruding in the same direction as the direction,
The claw portion is disposed between the tip of the teeth portion and the claw portion, and a punch (87) that contacts at least the root (95) of the claw portion has a pivot axis (89) through which the punch passes. A method of manufacturing a stator core , wherein the stator core is bent so as to fall down from the base by the punch when rotating around. 2. The method of manufacturing a stator core according to claim 1, wherein the claw portion is bent by the punch that continuously contacts the base portion to the end portion (96) of the claw portion. The corner between the claw portion and the tip of the teeth portion is rounded before the claw portion is bent, and the center of curvature of the corner coincides with the rotation center of the punch. Item 3. A method for manufacturing a stator core according to Item 1 or 2. The opposing surface (99) facing the punch just before the claw portion is bent out of the claw portion is a virtual circle concentric with the central hole (98) of the annular core sheet after the claw portion is bent. The method for manufacturing a stator core according to any one of claims 1 to 3, wherein the surface is an arcuate surface that coincides with (C). Out of the claw portions, the opposing surface (99) facing the punch just before the claw portion is bent is a receiving member (88 disposed on both sides in the width direction with respect to the teeth portion when the claw portion is bent. ) And the punch, and is formed into an arcuate surface that coincides with a virtual circle (C) concentric with the central hole (98) of the annular core sheet. The manufacturing method of the stator core as described in any one of these. A plurality of depressions (94) are formed between the claw portion and the side surface (93) of the teeth portion before the claw portion is bent. A method for manufacturing a stator core according to one item.

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