JP2011182620A - Method and device for manufacturing stacked iron core - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for manufacturing a stacked iron core which lessens the broken-out section at the inner circumference of a stator. <P>SOLUTION: A small teeth pressing punch 9 has a columnar punch holder 56 in which a plurality of holding slots 55 are formed axially at the periphery, groove pressing punches 57 which are set in respective holding slots 55, and a locking ring 58 which is fitted in the outside of the upper part of the punch holder 56 to prevent the fall of the groove pressing punches 57. Moreover, a guide plate 51 consists of a disc-shaped guide part 51a which is roughly the same in diameter as the punch holder 56 and in which a taper is formed on the tip side, and a stem 51b which is projected upward from the center of the guide 51a, and the stem 51b fits in a holding hole 56a formed in the punch holder 56. The outer diameter of the punch holder 56 and the guide plate 51 (guide part 51a) is set to be roughly equal (loose-fitting) to or smaller than the diameter of the inner circumference Cis of the stator. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for manufacturing a laminated iron core used for a stator or a rotor of a rotating electric machine, and relates to a technique for preventing burrs from being generated on the inner peripheral surface of a stator small tooth.

  A laminated iron core for a rotating electrical machine is often manufactured from a hoop material (strip-shaped thin steel sheet) of an electromagnetic steel sheet by a progressive die apparatus because cutting of slots and small teeth is complicated and difficult. For example, a laminated iron core for stators is made by continuously punching holes such as pilot holes, slots, inner peripheral teeth, and outer shapes on a hoop material that is intermittently transferred in a progressive die, thereby continuously forming an annular core sheet. After being obtained, it is manufactured by laminating and integrating a certain number of these iron core thin plates in a die.

  Although there are some processing defects (burrs, sagging, breakage, etc.) on the punched surface of the iron core thin plate, in the laminated core for a stepping motor, the stator magnetic pole and the rotor magnetic pole have a very small gap (air gap). Therefore, a processing defect on the tip surface (inner peripheral surface or outer peripheral surface) of the magnetic pole becomes a factor that deteriorates the product performance. Therefore, a method is known in which the iron sheet is subjected to post-processing (shaving) in the final process of the progressive die, and the processing defect at the tip of the magnetic pole is removed to obtain a smooth end face (see Patent Documents 1 and 2). . Note that broaching or honing is also employed as post-processing of the punched surface.

JP-A-6-269149 JP 2000-50579 A

  However, in the conventional apparatus, as shown in FIG. 12, since the stator small teeth Ts are punched out by the small tooth punching punch 9 having the grooved portion 9a projecting on the outer periphery, the portion adjacent to the grooved portion 9a of the workpiece W. Bulges inward, and a burr 83 may be formed at the end of the inner peripheral surface of the stator small teeth Ts as shown in FIG. In the laminated iron core for a stepping motor, since the air gap between the stator and the rotor is very small as described above, it is necessary to perform post-processing (shaving) on the iron core thin plate in the final process to remove the above-described burrs. It was.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a method and an apparatus for manufacturing a laminated core in which burrs are not generated on the inner peripheral surface of a stator small tooth.

  According to a first aspect of the present invention, there is provided a method for manufacturing a laminated iron core, wherein a stator core thin plate having small teeth on an inner periphery is punched from a strip-shaped thin steel plate using a progressive die, and the stator core thin plate is sequentially laminated and integrated in a die. A method of manufacturing a laminated iron core for a stator, the inner peripheral punching step of punching the inner periphery of the stator core thin plate from the strip thin steel plate, and the strip thin steel plate with the inner periphery punched, A small tooth punching step for punching small teeth of the stator core thin plate, and in the small tooth punching step, a punch holder having a diameter substantially the same as or smaller than the inner periphery of the stator core thin plate and held by the punch holder A small-tooth punch having a grooved punch is used.

  According to a second aspect of the present invention, in the method for manufacturing a laminated core according to the first aspect, a plurality of holding slots are formed along an axial direction on an outer periphery of the punch holder, and the groove punch is fitted into the holding slot. A method for producing a laminated iron core, characterized in that

  A laminated core manufacturing apparatus according to a third aspect of the present invention uses a progressive die to punch out a stator core thin plate having small teeth on the inner periphery from a strip-shaped steel plate, and sequentially stack and integrate the stator core thin plate in a die. An inner peripheral punching device comprising an inner peripheral punch, and punching the inner periphery of the stator core thin plate with the inner peripheral punch, and small tooth punching A small tooth punching means for punching small teeth of the stator core thin plate with the small tooth punching punch for the strip-shaped thin steel sheet having an inner periphery punched, the small tooth punching punch comprising: A punch holder having substantially the same diameter or a small diameter as the inner periphery of the stator core thin plate, and a groove punch held by the punch holder.

  According to a fourth aspect of the present invention, in the laminated core manufacturing apparatus according to the third aspect of the invention, a plurality of holding slots are formed along the axial direction on the outer periphery of the punch holder, and the groove punch is fitted into the holding slot. It is characterized by that.

  According to the first and third aspects of the invention, when the grooving punch bites into the workpiece, the inner peripheral surface of the small teeth is pressed by the punch holder, so that no burr is generated and no post-processing is required. If the punch holder is made smaller in diameter than the inner circumference of the stator core thin plate, the end diameter of the small teeth protrudes toward the inner circumference, so that the finished diameter of the stator inner circumference can be reduced, and the laminated core for rotor The performance of the stepping motor can be improved by reducing the air gap between the stator and the laminated core for the stator. In addition, according to the second and fourth inventions, the manufacture of the small tooth punch is facilitated, and the device cost is reduced.

It is the strip layout figure of the first half which concerns on embodiment. It is the latter half strip layout figure which concerns on embodiment. It is a longitudinal cross-sectional view of the metal mold | die in the 7th process of embodiment. It is a perspective view which shows the form of the scrap half extraction which concerns on embodiment. It is a principal part longitudinal cross-sectional view which shows the form of the scrap half extraction which concerns on embodiment. It is a longitudinal cross-sectional view of the metal mold | die in the 8th process of embodiment. It is a principal part longitudinal cross-sectional view which shows the stator inner periphery punching process which concerns on embodiment. It is a perspective view which shows the form of the stator inner periphery punching which concerns on embodiment. It is a longitudinal cross-sectional view of the metal mold | die in the 9th process of embodiment. It is a principal part longitudinal cross-sectional view which shows the stator small tooth punching process which concerns on embodiment. It is a perspective view which shows the partial modification of a stator inner peripheral punching process. It is a top view which shows the principal part of the small tooth punching process in a conventional apparatus. It is a principal part perspective view of the workpiece | work which shows the problem of a conventional apparatus.

[Embodiment]
Hereinafter, an embodiment of a laminated core manufacturing apparatus to which the present invention is applied will be described in detail with reference to the drawings. In addition, the laminated core manufacturing apparatus of this embodiment manufactures continuously the laminated iron core for stators for stepping motors, and the laminated iron core for rotors.

<< Configuration of Embodiment >>
<Processing flow>

  While the hoop material W is intermittently fed in the progressive die, the first to twelfth steps are subjected to press working, whereby the rotor laminated core LCr and the stator laminated core LCs are manufactured. That is, in the hoop material W, as shown in FIG. 1, the pilot hole P punching process (1) using the pilot hole punch 1, the rotor measuring hole Kr1 punching process (2) using the rotor measuring hole punch 2, and the rotor Half-drawing step (3) of the rotor caulking projection Kr2 by the caulking punch 3, (4) punching step of the rotor shaft hole Hr by the rotor shaft hole punch 4, and rotor outer shape Or (ie, the rotor core thin plate 61 for the rotor) by the rotor outer shape punch 5. Punching step (5), status lot punching process (6) with status lot punch 6 and scrap half punching step (7) with scrap half punching punch 7 are performed.

  Next, as shown in FIG. 2, the stator inner periphery Cis punching step (8) by the stator inner periphery punching punch 8, and the small teeth 72 punching step on the stator core thin plate 71 side by the small tooth punching punch 9 are performed. (9), the stator measuring hole Ks1 punching step (10) by the stator measuring hole punch 10, the stator caulking projection Ks2 half-punching step (11) by the stator caulking punch 11, and the stator outer shape Os by the stator outer punch 12 (ie, A stamping step (12) of the stator core thin plate 71) is sequentially performed. The rotor metering hole Kr1 and the stator metering hole Ks1 are punched only once every predetermined number of times (for example, 50 times), whereby the number of laminated core sheets 61 for the rotor and the core sheet 71 for the stator (that is, The thickness of the laminated iron core LCr for rotor and the laminated iron core LCs for stator) is determined.

<Scrap half extraction process>
As shown in FIG. 3, the mold in the seventh step includes a scrap half punch 7 held on the upper holder 21 via the sheet plate 22 and the punch plate 23, and a die 25 held on the lower holder 24. And have. The scrap half punching punch 7 has a cylindrical shape and is chamfered at the lower end. In FIG. 3, a member denoted by reference numeral 26 is a stripper body, and a stripper plate 27 that presses the hoop material W against the die 25 is fixed to the lower surface thereof. In addition, the member shown with the code | symbol 28 is a knock pin, and the member shown with the code | symbol 29 is a volt | bolt.

  In the seventh step, when the scrap half-punch punch 7 is lowered together with the upper mold holder 21, as shown in FIG. 4, a semicircular scrap half-punch with respect to the hoop material W in which the rotor outer shape Or has been punched. 31 is applied. The scrap half punch 31 is applied to the outside of the convex portion 32 corresponding to the small teeth on the rotor core thin plate (not shown) side. And since the chamfer 7a is given to the lower end of the scrap half punching punch 7, as shown in FIG. 5, the convex part 32 comes to incline in a slanting inner side without falling off from the scrap half punching 31. .

<Stator inner circumference punching process>
As shown in FIG. 6, the mold in the eighth step includes a cylindrical stator inner punching punch 8 held on the upper mold holder 21 via a sheet plate 22 and a punch plate 23, and a stator inner peripheral punching. A scrap ejector 41 installed below the punch 8 and a die 42 held by the lower mold holder 24 are provided.

  The scrap ejector 41 includes an ejector plate 41 a having a smaller diameter than the stator inner peripheral punch 8 and a stem 41 b protruding upward from the center of the ejector plate 41 a, and is formed on the stator inner peripheral punch 8. A stem 41b is slidably fitted in the guide hole 8a. A guide bolt 43 is screwed into the shaft center of the stem 41b, and the head of the guide bolt 43 is locked to an inward flange 8b formed in the stator inner peripheral punching punch 8. A compression coil spring 44 is accommodated in the guide hole 8 a of the stator inner periphery punching punch 8, and the scrap ejector 41 is always urged downward by the spring force of the compression coil spring 44.

  When the punch plate 23 is lowered, as shown in FIG. 7A, the lower end of the punch plate 23 is locked to the scrap half-punch 31 and the convex portion 32, so that the scrap ejector 41 rises while compressing and compressing the compression coil spring 44. After contacting the lower surface of the stator inner periphery punching punch 8, the stator inner periphery punching punch 8 bites into the hoop material W, and punching of the stator inner periphery Cis is started. When the punch plate 23 is further lowered, as shown in FIG. 7 (b), the punching of the stator inner circumference Cis is completed, and the scrap 45 is separated from the hoop material W and protrudes by the spring force of the compression coil spring 44. 41 causes the scrap 45 to fall downward.

  In the present embodiment, since the semicircular scrap half-punch 31 is performed in the scrap half-pulling step, the stator inner circumference Cis is punched concentrically and annularly with the scrap half-pull 31. Therefore, FIGS. ), There is no wide portion in the scrap 45, and a large fracture surface 46 due to the action of the tensile force, which is a problem in the conventional apparatus, does not occur in the stator inner periphery Cis. That is, only a very small fracture surface 46 that does not deteriorate the product performance is generated at the lower portion of the stator inner periphery Cis, and the area of the smooth surface 47 is increased. As a result, as shown in FIG. 8C, when the small teeth 72 on the stator core thin plate 71 side are formed in the stator small tooth punching step described later, the smooth surface 47 on the inner peripheral side end surface of the small teeth 72 is formed. The area becomes uniform and large, and the performance of the stepping motor is significantly improved (rotational characteristics and the like are improved). In this embodiment, since the scrap 45 is forcibly dropped by the scrap ejector 41, the scrap rise is effectively suppressed even though the width of the scrap 45 is very small.

<Stator small tooth punching process>
As shown in FIG. 9, the mold in the ninth step is a small tooth punching punch 9 held on the upper mold holder 21 via a sheet plate 22 and a punch plate 23, and a lower surface of the small tooth punching punch 9. A fixed guide plate 51 and a die 52 held by the lower mold holder 24 are provided.

  The small tooth punch 9 has a cylindrical punch holder 56 having a plurality of holding slots 55 formed along the axial direction on the outer periphery thereof, a groove punch 57 fitted in each holding slot 55, and a punch holder 56. And a locking ring 58 that is externally fitted to the upper portion to prevent the groove punching punch 57 from falling off. The guide plate 51 is composed of a disc-shaped guide portion 51a that is substantially the same diameter as the punch holder 56 and has a taper on the tip side, and a stem 51b that protrudes upward from the center of the guide portion 51a. The stem 51 b is fitted in the holding hole 56 a formed in the punch holder 56. The outer diameters of the punch holder 56 and the guide plate 51 (guide portion 51a) are set equal to or smaller than the diameter of the stator inner circumference Cis.

  When the punch plate 23 is lowered, the guide plate 51 is fitted into the stator inner circumference Cis of the hoop material W as shown in FIG. At this time, since the taper is formed on the distal end side of the guide portion 51a, even if there is a slight deviation between the hoop material W and the guide plate 51, the position of the hoop material W is corrected and smooth insertion is achieved. Done. When the punch plate 23 is further lowered, the punch holder 56 of the small tooth punching punch 9 is fitted into the stator inner circumference Cis of the hoop material W and the groove punching punch 57 is formed on the hoop material W as shown in FIG. The small teeth 72 on the stator core thin plate 71 side are punched out.

  In the case of the present embodiment, since the outer diameter of the punch holder 56 is set to be substantially the same as the diameter of the stator inner circumference Cis, when the groove punch 57 bites into the hoop material W, the outer circumference of the punch holder 56 causes burrs. Generation | occurrence | production is suppressed and surplus thickness does not protrude inside, and it is prevented that a burr | flash generate | occur | produces on the inner periphery (stator inner periphery Cis) of the iron core thin plate 71 for stators. As a result, a highly accurate air gap can be obtained without post-processing the stator laminated core LCs, and the performance of the stepping motor or the like can be improved without increasing the number of manufacturing steps or the manufacturing cost. Further, in the present embodiment, the holding slot 55 is formed in the cylindrical punch holder 56, and the groove punch 57 is fitted in the holding slot 55, so that the small tooth punching punch 9 can be easily manufactured. The apparatus cost can be reduced. Further, when the outer diameter of the punch holder 56 is made smaller than the inner circumference Cis of the stator, the tip of the small tooth 72 projects to the inner circumference side (the surplus wall bulges to the outer circumference surface of the punch holder 56). ), The finished diameter of the stator inner circumference Cis can be reduced. As a result, the air gap between the rotor laminated core LCr and the stator laminated core LCs is reduced, and the performance of the stepping motor can be improved.

<Partial modification of stator inner peripheral punching process>
Next, a partial modification of the stator inner peripheral punching step will be described.
As shown in FIG. 11A, in this modification, a plurality of protrusion forming portions 8 c are projected on the outer periphery of the stator inner peripheral punching punch 8, and thereby, the floating prevention protrusion 45 a on the outer periphery of the scrap 45. Is formed. On the other hand, as shown in FIG. 11 (b), the die 42 is formed with anti-floating grooves 42a, and the anti-floating protrusions 45a of the scrap 45 are fitted into these anti-floating grooves 42a, thereby providing a scrap ejector. As in the embodiment described above, scraping is prevented.

  Although the description of the specific embodiment is finished as described above, the present invention is not limited to the above embodiment and can be widely modified. For example, in the above-described embodiment, the present invention is applied to a progressive mold for manufacturing a laminated core for a stator for a stepping motor and a laminated core for a rotor. However, the present invention is naturally applied to a progressive mold for manufacturing a laminated core for a general motor. It is applicable to. Further, the configuration of the strip layout, the specific structure of the mold, and the like can be changed as appropriate without departing from the spirit of the present invention.

7 Scrap Half Punch 8 Stator Inner Peripheral Punch 8c Projection Forming Part 9 Small Tooth Punch 41 Scrap Ejector 42a Levitation Prevention Groove 45 Scrap 45a Levitation Prevention Protrusion 46 Break 57 Groove Punch 58 Locking Ring 61 Rotor Core Thin Plate 71 Iron core thin plate for stator 72 Small teeth W Hoop material

Claims (4)

Using a progressive die, a stator core thin plate having small teeth on the inner periphery is punched out from a strip-shaped thin steel plate, and the stator core thin plate is sequentially laminated and integrated in a die to produce a laminated core for a stator. There,
An inner peripheral punching process for punching an inner periphery of the stator core thin sheet from the strip-shaped thin steel sheet; and
A small tooth punching step of punching small teeth of the stator core thin plate with respect to the strip-shaped thin steel plate in which the inner periphery is punched,
In the small tooth punching step, a small tooth punch having a punch holder having the same diameter or a small diameter as the inner circumference of the stator core thin plate and a groove punch held by the punch holder is used. A method for producing a laminated iron core.   A method of manufacturing a laminated iron core, wherein a plurality of holding slots are formed along an axial direction on an outer periphery of the punch holder, and the groove punch is fitted into the holding slot. An apparatus that manufactures a laminated core for a stator by punching out a stator core thin plate having small teeth on the inner periphery from a strip-shaped thin steel plate using a progressive die and sequentially laminating and integrating the stator core thin plate in a die. There,
An inner periphery punching means comprising an inner periphery punch, and punching the inner periphery of the stator core thin plate by the inner periphery punch,
A small tooth punching punch, comprising a small tooth punching means for punching small teeth of the iron core thin plate for the stator by the small tooth punching punch with respect to the strip-shaped thin steel plate punched out of the inner circumference;
The small tooth punch has a punch holder having a diameter substantially the same as or smaller than the inner circumference of the stator core thin plate and a groove punch held by the punch holder.   The laminated core manufacturing apparatus according to claim 3, wherein a plurality of holding slots are formed along an axial direction on an outer periphery of the punch holder, and the groove punch is fitted into the holding slot.

Images