JP6630123B2 - Laminated core and method of manufacturing the same - Google Patents

Description

  The present invention relates to a laminated iron core constituting a rotor and a method for manufacturing the same.

  The laminated core is a component of the motor, and is formed by stacking a plurality of electromagnetic steel plates (worked bodies) processed into a predetermined shape and fastening them. The motor includes a rotor (rotor) and a stator (stator) made of a laminated iron core, and is completed through a process of attaching a shaft to the rotor, a process of winding a coil around the stator, and the like. The laminated core constituting the rotor has a plurality of poles, and each pole has one or more permanent magnets. These permanent magnets are housed in a magnet housing area (slot) provided in the laminated core. A motor having a rotor having such a configuration is called an IPM (Interior Permanent Magnet) motor.

  As a rotor composed of a laminated iron core having a magnet accommodating region, a plurality of magnet accommodating regions were arranged at predetermined intervals in a circumferential direction, and a processed body having a fan-shaped main body portion formed between adjacent magnet accommodating regions was laminated. A rotor is known (for example, see Patent Document 1). Further, as a method of manufacturing a laminated iron core constituting a rotor, a plurality of punched workpieces of a predetermined shape are punched by supplying an electromagnetic steel plate (worked plate) to a progressive die, and punching the progressive die. There is known a method of obtaining a laminated iron core by stacking processed bodies (for example, see Patent Document 2).

JP 2001-37121 A JP 2003-212238 A

  When a workpiece is obtained by punching, residual stress in the workpiece due to the punching load becomes a problem. The residual stress may cause deformation of the laminated core. When a machined body in which a plurality of magnet housing regions are arranged in a plurality in the circumferential direction as described in Patent Literature 1 is obtained by punching, residual regions based on the punching load are reduced by increasing the punching region. Easy to grow. Such residual stress causes deformation of the laminated iron core, particularly when it is present at a location where the strength is weak.

  The present invention has been made in view of the above circumstances, and has as its object to provide a laminated iron core that suppresses deformation due to residual stress and a method for manufacturing the same.

  The method for manufacturing a laminated core according to one embodiment of the present invention includes: (A) a step of supplying a plate to be processed to a mold; Forming a plurality of magnet accommodating regions arranged at intervals of, and forming a main body portion and a connecting portion having a narrower circumferential width than the main body portion as a magnetic flux passage sandwiched between the magnet accommodating regions. And (C) a step of crushing a corresponding area, which is an area corresponding to the connection portion, by the mold and work hardening the corresponding area; and (D) the steps (B) and (C). Performing a process, stacking a plurality of workpieces obtained from the plate to be processed, and fastening them to obtain a laminated iron core.

  In the method for manufacturing a laminated core, in the step (C), a region corresponding to the connection portion is work-hardened by crushing. Since the connecting portion has a small width in the circumferential direction and a small area, the connecting portion has low strength and is easily deformed by residual stress based on a punching load. In this regard, in the method for manufacturing the laminated core, since the region corresponding to the connection portion is work-hardened, deformation of the connection portion due to residual stress can be suppressed. As described above, according to the method for manufacturing a laminated core, deformation due to residual stress can be suppressed in the laminated core of the rotor, which is a laminated body of the processed body in which the plurality of magnet housing regions are arranged.

  The step (C) may include a step of crushing the entire corresponding region with the die. As a result, the entire area of the region corresponding to the connection portion is work-hardened, so the work-hardened region becomes large, and deformation of the connection portion can be more effectively suppressed.

  The step (C) may include a step of crushing only one side in the circumferential direction of the corresponding area with the mold. By performing the crushing process on only one side, the one side is plastically deformed, and a force is generated in a direction opposite to the one side direction. Thus, for example, when a residual stress is applied in one side direction, a force for canceling the residual stress is generated by the crushing process, so that the deformation of the connection portion in the direction of the residual stress can be corrected.

  In the step (B), a plurality of steps are performed so as to form a region in contact with the corresponding region of each magnet housing region so that regions adjacent to the corresponding region of the magnet housing regions adjacent in the circumferential direction are not formed at the same time. The step C) may include a step of performing a crushing process with a mold only on the magnet housing area side in which the area in contact with the corresponding area is formed later. The connecting portion has a residual stress based on a punching load when forming the magnet housing region. More specifically, a residual stress exists in the direction of the punched magnet housing area in the connection portion. Here, when the region in contact with the corresponding region of the plurality of magnet housing regions is formed in a plurality of steps, the punching load applied to the corresponding region at the time of punching increases in later steps. In other words, the area of the plate to be subjected to the punching load becomes smaller in a later process, so that a larger punching load is applied to a considerable area. For this reason, in the connection portion, the residual stress in the direction of the magnet accommodating region punched in a later step is greater. In this regard, in the corresponding area, the area in contact with the corresponding area is subjected to the crushing process on the magnet housing area side formed later, thereby effectively correcting the deformation of the connecting portion in the direction in which the residual stress is applied more. be able to.

  The step (C) may include a step of performing a crushing process by using a mold only on the magnet accommodating region side in which the region in contact with the corresponding region in the corresponding region is formed first. This makes it possible to generate a force that offsets the residual stress based on the punching of the magnet housing area in the previous step. This makes it possible to appropriately correct not only the punching of the subsequent step but also the deformation of the connecting portion based on the punching of the previous step.

  A laminated iron core according to one embodiment of the present invention includes a cylindrical portion, a plurality of main portions which are formed at predetermined intervals in a circumferential direction on a radially outer side of the cylindrical portion, and serve as a magnetic flux passage; And a connecting portion having a smaller circumferential width than the main body portion, and a magnet housing space formed between the adjacent main body portions, the connecting portion having at least one connecting portion. The part area is work hardened.

  According to one embodiment of the present invention, deformation due to residual stress can be suppressed.

FIG. 1 is a perspective view showing an example of a laminated core constituting a rotor. FIG. 2 is a plan view showing a processed body included in the laminated core shown in FIG. FIG. 3 is an enlarged perspective view showing a region OE shown in FIG. FIG. 4 is a schematic view showing an example of the punching device. FIGS. 5A to 5F are plan views showing the entire layout of the punching process. 6A and 6B are enlarged plan views of FIGS. 5A and 5B of the layout shown in FIG. FIGS. 7A and 7B are enlarged plan views of FIGS. 5C and 5D of the layout shown in FIG. 8A and 8B are enlarged plan views of FIGS. 5E and 5F of the layout shown in FIG. FIG. 9A is an enlarged plan view of the area SE1 shown in FIG. 7B, and FIG. 9B is an enlarged plan view of the area SE2 shown in FIG. 8A. FIG. 10 is an enlarged perspective view showing a connecting portion according to a modification.

  Embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same elements or elements having the same functions will be denoted by the same reference symbols, without redundant description.

<Laminated core and processed body>
FIG. 1 is a perspective view of a laminated core R constituting a rotor. The laminated core R has a substantially cylindrical shape, and an opening Ra located at the center is for mounting a shaft (not shown). A convex key (not shown) may be provided on the inner peripheral surface Rb constituting the opening Ra as a structure for mounting the shaft.

  The laminated core R is configured by laminating a plurality of processed bodies PB (see FIG. 2). FIG. 2 is a plan view showing a processed body PB included in the laminated core R shown in FIG. The processed body PB is obtained from an electromagnetic steel plate (worked plate) by punching with a die described later. The processed body PB includes a ring-shaped annular portion 111, a plurality of magnet housing regions 112 arranged at predetermined intervals in a circumferential direction around the annular portion 111, and a magnetic flux sandwiched between the plurality of magnet housing regions 112. A main body portion 113 serving as a passage, a connecting portion 115 having a smaller circumferential width than the main body portion, and a convex portion 114 extending from the outer peripheral surface PBc of the annular portion 111 toward the magnet housing area 112. I have.

  For example, eight magnet housing areas 112 are provided at equal intervals in the circumferential direction. Each magnet accommodating region 112 has an inner region 112b that is in contact with the annular portion 111, and an outer region 112c that is continuous with the inner region 112b and that is located radially outward from the inner region 112b. The inner area 112b is, for example, half or more the size of the entire magnet housing area 112. The inner region 112b is formed before the outer region 112c (details will be described later). The inner regions 112b of the magnet housing regions 112 adjacent to each other in the circumferential direction are not formed at the same time. That is, first, the first inner region 112x, which is the inner region 112b of some of the magnet housing regions 112 that are not adjacent to each other, is formed, and then the first inner region 112b of the remaining magnet housing region 112 that is not adjacent to each other is formed. Two inner regions 112y are formed (details will be described later). Therefore, in the circumferential direction, the first inner regions 112x and the second inner regions 112y are alternately located.

  The main body portion 113 is formed in a substantially fan shape in plan view. The main body portion 113 has joining portions 113a and 113b on the radial outside and the radial inside. In the joining portions 113a and 113b, the stacked bodies R are configured by fastening the workpieces PB overlapping in the vertical direction by caulking. That is, each of the processed bodies PB has the joints 113a and 113b that form a concave portion on the front surface and a convex portion on the back surface. The upper and lower workpieces are fastened by fitting the back surface (convex portion) of the upper workpiece PB and the front surface (recess) of the lower workpiece PB. In addition, in order to prevent the plurality of laminated cores R from being fastened to each other, the processed body PB located at the lowermost part of the laminated body has perforations at the joints 113a and 113b instead of the convex and concave portions.

  Although the laminated core R has been described as being configured by stacking the work pieces PB and fastening them by caulking, any method of fastening the work body PB may be used. For example, the plurality of workpieces PB may be fastened to each other by welding, bonding, or a resin material. In view of cost and work efficiency, caulking and welding have been widely adopted. On the other hand, when giving priority to high torque and low iron loss of the motor, a resin material or an adhesive may be used instead of caulking or welding. Further, the provisional caulking may be provided on the processed body PB, and the processed bodies PB may be fastened to each other by this, and then the laminated core R may be obtained by finally removing the provisional caulking from the laminated body. The term “temporary caulking” refers to caulking used to temporarily integrate a plurality of workpieces manufactured by punching and removed in the process of manufacturing a product (laminated core).

  Further, an outer collar 113e that protrudes toward the adjacent magnet housing area 112 is provided radially outside the main body portion 113.

  The connecting portion 115 extends from the outer peripheral surface PBc of the annular portion 111 toward the main body portion 113, and connects (connects) the annular portion 111 and the main body portion 113 between the plurality of magnet housing areas 112.

  FIG. 3 is an enlarged perspective view showing a region OE shown in FIG. As shown in FIG. 3, deformed portions 115 a and 115 b that are plastically deformed and work hardened (strain hardened) by crushing by a die described later are formed in the connecting portion 115. The deformation portion 115a is formed over the entire area of the connection portion 115. Further, the deformed portion 115b is formed only on one side in the circumferential direction of the connecting portion 115. More specifically, the deformed portion 115b is formed on the side of the connecting portion 115 that contacts the second inner region 112y. In addition, the deformed portion 115b is formed at a radially central portion of the connecting portion 115, and is not formed at both ends in the radial direction.

  The laminated core R shown in FIG. 1 is configured by laminating the above-described processed bodies PB. The laminated core R includes a cylindrical portion 11 surrounding a shaft (rotating shaft), a plurality of magnet housing spaces 12 formed at predetermined intervals in a circumferential direction on a radially outer side of the cylindrical portion 11, and a magnet housing space 12 adjacent to each other. And a main body portion 13 formed between the magnetic flux passages. The magnet housing space 12 is a space for housing one or more permanent magnets (for example, a sintered magnet such as a neodymium magnet or a bond magnet). The cylindrical portion 11, the magnet housing space 12, and the main body 13 are formed by laminating the annular portion 111, the magnet housing area 112, and the main body portion 113 of the processed body PB, respectively.

  An outer brim portion 13e that protrudes toward the adjacent magnet housing space 12 from the upper surface to the lower surface of the main body portion 13 is provided radially outside the main body portion 13. The size and shape of the outer brim portion 13e are determined as appropriate from the viewpoint of appropriately fixing a magnet (not shown) in the magnet accommodating space 12 and suppressing the leakage magnetic flux to be small. The outer collar portion 13e is formed by laminating the outer collar 113e.

  Further, the laminated core R includes a convex portion 14 extending from the outer peripheral surface Rc of the cylindrical portion 11 toward the magnet housing space 12, and a connecting portion 15 extending from the outer peripheral surface Rc toward the main body portion 13. The convex portion 14 and the connecting portion 15 are formed by stacking the convex portion 114 and the connecting portion 115 of the workpiece PB. The connecting portion 15 is formed between the magnet accommodating spaces 12 adjacent to each other, has a smaller circumferential width than the main body portion 13, and has a region corresponding to the deformed portions 115a and 115b which is work hardened. I have.

<Punching device>
FIG. 4 is a schematic diagram showing an example of a punching apparatus for manufacturing a workpiece PB constituting the laminated core R by punching. The punching apparatus 100 shown in FIG. 1 includes an uncoiler 110 on which the winding body C is mounted, a feeding device 130 for an electromagnetic steel sheet (hereinafter, referred to as “working board W”) drawn from the winding body C, and a working board W. And a press machine 120 for operating the progressive die 140.

  The uncoiler 110 holds the wound body C rotatably. The length of the work plate W constituting the wound body C is, for example, 500 to 10000 m. The thickness of the work plate W constituting the wound body C may be about 0.1 to 0.5 mm, and from the viewpoint of achieving more excellent magnetic properties of the laminated core R, 0.1 to 0.3 mm. Degree. The width of the work plate W may be about 50 to 500 mm.

  The feed device 130 has a pair of rollers 130a and 130b that sandwich the work plate W from above and below. The work plate W is introduced into the progressive die 140 via the feed device 130. The progressive die 140 is for continuously performing punching, bending, cutting and bending, pushback, crushing, and the like on the plate W to be processed.

<Production method of laminated core>
Next, a method of manufacturing the laminated core R will be described. The laminated core R includes a process of manufacturing a processed body PB (steps (A), (B), and (C) below) and a process of manufacturing the laminated core R from a plurality of processed bodies PB (described below (D)). Step). More specifically, the method for manufacturing the laminated core R includes the following steps.
(A) A step of supplying the work plate W to the progressive die 140.
(B) The workpiece W is punched by the progressive die 140 to form a plurality of magnet accommodating regions 112 arranged at predetermined intervals in the circumferential direction, and the magnetic flux sandwiched between the magnet accommodating regions 112 is formed. Forming a main body portion 113 and a connecting portion 115 having a smaller circumferential width than the main body portion 113 as a passage;
(C) A step of crushing the equivalent area 115z, which is an area corresponding to the connecting portion 115, by the progressive die 140, and work hardening the equivalent area 115z. (D) The steps (B) and (C) A step of obtaining a laminated core R by stacking a plurality of processed bodies PB obtained from the work plate W by performing the steps, and fastening them.

  First, a wound body C of an electromagnetic steel sheet is prepared, and is mounted on the decoiler 110. The electromagnetic steel plate (working plate W) drawn from the winding body C is supplied to the progressive die 140 ((A) step).

  By punching the workpiece W in the progressive die 140, a workpiece PB on which the magnet accommodating region 112, the main body portion 113, and the connecting portion 115 are formed is continuously manufactured ((B) process). . Further, in the present embodiment, in the middle of the step (B), the progressive die 140 forms an area that is later formed as the connecting part 115, and corresponds to the connecting part 115 sandwiched between the magnet housing areas 112. Is performed, and the corresponding region 115z is plastically deformed and work-hardened (step (C)). More specifically, in the step (C), the entirety of the corresponding area 115z is crushed by the progressive die 140 to form the deformed portion 115a. Further, in the step (C), further deformation is performed only on one side in the circumferential direction of the corresponding region 115z by the progressive die 140 to form the deformed portion 115b.

  Hereinafter, the steps (B) and (C) will be described with reference to FIGS. FIGS. 5A to 5F are plan views showing the entire layout of the punching process. 6A and 6B are enlarged plan views of FIGS. 5A and 5B of the layout shown in FIG. FIGS. 7A and 7B are enlarged plan views of FIGS. 5C and 5D of the layout shown in FIG. 8A and 8B are enlarged plan views of FIGS. 5E and 5F of the layout shown in FIG. The layout of the punching process is not limited to the layout shown in FIG. 5, and a step for balancing the press load may be added, or a step for forming temporary crimping may be added. . The step (B) includes steps B1 to B6 described below, and the step (C) includes steps C1 and C2 described later.

  Step B1 is a step of forming a pilot hole P in the work plate W (see FIGS. 5A and 6A). The pilot hole P is for positioning the workpiece W in the progressive die 140.

  The B2 step is a step of forming a first inner region 112x that is formed in advance among the inner regions 112b of the plurality of magnet housing regions 112 (see FIGS. 5B and 6B). In the B2 step, a first inner region 112x, which is an inner region 112b of four magnet housing regions 112 that are not adjacent to each other in the circumferential direction among the eight magnet housing regions 112, is formed.

  The B3 step is a step of forming a second inner area 112y formed following the first inner area 112x among the inner areas 112b of the plurality of magnet housing areas 112 (FIGS. 5C and 7A). )reference). In the B3 step, four magnet housing areas 112 that are not adjacent to each other in the circumferential direction (four places except the magnet housing area 112 including the above-described first inner area 112x) among the eight magnet housing areas 112 formed. Is formed as a second inner region 112y, which is the inner region 112b.

  As described above, in the process of forming the inner region 112b (steps B2 and B3), the inner region 112b of the magnet housing region 112 adjacent in the circumferential direction (the region in contact with the corresponding region 115z of the magnet housing region 112) is simultaneously formed. In order to avoid this, the first inner region 112x and the second inner region 112y are formed in a plurality of steps, specifically, two steps.

  By performing the B2 step and the B3 step, a corresponding area that will later become the connecting portion 115 is provided between the magnet housing areas 112 adjacent in the circumferential direction (more specifically, between the first inner area 112x and the second inner area 112y). 115z is formed (see FIG. 7A). The equivalent region 115z has the same circumferential width as the connecting portion 115.

  The B4 step is a step of forming a concave portion (a convex portion when viewed from the back surface) or a hole at a position corresponding to the joining portions 113a and 113b of the main body portion 113 in the processed body PB (FIG. 5D and FIG. b)). That is, in the B4 step, when manufacturing a workpiece other than the work piece PB located at the lowermost portion of the laminated core R, a concave portion is formed at a position corresponding to the joining portions 113a and 113b by bending, and the lowermost portion of the laminated core R is formed. In the case of manufacturing the processed body PB located at the position, the perforations are formed at positions corresponding to the joining portions 113a and 113b by punching.

  Further, the C1 step is performed together with the B4 step. The C1 step is a step of performing a crushing process on the entire corresponding area 115z. In step C1, crushing is performed using a stripper (not shown) attached to the lower surface of the upper die (punch) of the progressive die 140. The stripper is used for applications such as sandwiching the workpiece plate W between the lower die (die). In this embodiment, a projection (not shown) is provided on the stripper, and the corresponding region 115z is crushed by pressing the corresponding region 115z from above with the projection. That is, in the step C1, the entire area of the corresponding area 115z is pressed by the projection of the stripper, and the entire area is crushed. Note that the crushing process in the C1 step may be performed on all (eight) equivalent regions 115z between the magnet housing regions 112 or only on a part (for example, four) of the equivalent regions 115z. May be performed.

  FIG. 9A is an enlarged view of the area SE1 shown in FIG. 7B. As shown in FIG. 9A, when the entire region of the equivalent region 115z is subjected to the crushing process in the C1 step, a plastically deformed and work-hardened deformed portion 115a is formed over the entire region of the equivalent region 115z. . The amount of depression of the deforming portion 115a, that is, the amount of crushing by the crushing process in the C1 step is about 10 to 50 μm, for example, about 20 to 30 μm.

  The B5 step is a step of forming the central region 111a by punching the inside of the annular portion 111 (see FIGS. 5E and 8A).

  In addition, the C2 step is performed together with the B5 step. The C2 step is a step of performing crushing processing on only one side in the circumferential direction of the corresponding area 115z. In the C2 step, similar to the above-described C1 step, a crushing process is performed using a projection (not shown) of a stripper attached to the lower surface of the upper die (punch). That is, in the step C2, one side in the circumferential direction of the corresponding area 115z is pressed by the projection of the stripper, and the area on the one side is crushed. More specifically, in the C2 step, the crushing process is performed only on the side of the corresponding region 115z that is in contact with the second inner region 112y (the magnet housing region 112 side on which the inner region 112b is formed later). Note that the crushing process in the C2 step may be performed on all (eight) equivalent regions 115z between the magnet housing regions 112 or only on a part (for example, four) of the equivalent regions 115z. May be performed.

  FIG. 9B is an enlarged view of the area SE2 shown in FIG. 8A. As shown in FIG. 9B, when the crushing process is performed on only one side (the side in contact with the second inner area 112 y) in the circumferential direction of the equivalent area 115 z in the step C2, the second inner area in the equivalent area 115 z is formed. A deformed portion 115b that is plastically deformed and hardened is formed only on the side in contact with 112y. That is, in the corresponding region 115z, the deformed portion 115a is formed over the entire region, and the deformed portion 115b is further formed on the side in contact with the second inner region 112y. The amount of depression of the deforming portion 115b, that is, the amount of crushing by the crushing process in the C2 step is about 10 to 50 μm, for example, about 30 to 40 μm.

  Step B6 is a step of forming an outer region 112c formed following the inner region 112b in the magnet housing region 112 (see FIGS. 5F and 8B). In step B6, the outer regions 112c of the plurality of magnet housing regions 112 are formed collectively. Specifically, in the B6 step, a region radially outside the magnet housing region 112 with respect to the inner region 112b is formed as an outer region 112c.

  In step B6, the outer region 112c is formed such that a part of the outer region 112c overlaps the inner region 112b. That is, the punch passes in the punching of the inner region 112b (specifically, the first inner region 112x or the second inner region 112y) of the B2 step or the B3 step, and the punch passes in the punching of the outer region 112c of the B6 step. The plate W to be processed is punched such that the portion to be overlapped is overlapped. Thus, the inner region 112b and the outer region 112c have overlapping regions where the regions overlap with each other.

  When the precision of the supply position of the workpiece W to the progressive die 140 and the accuracy of assembling the progressive die 140 are reduced, the punching accuracy of the progressive die 140 is reduced. May not be a continuous punched area, and burrs may be generated or uncut portions may become a problem. In this regard, since the inner region 112b and the outer region 112c partially overlap, even when the punching accuracy is reduced, the inner region 112b and the outer region 112c can be easily formed as a continuous region, and burrs are generated. Etc. can be suppressed.

  In the above-described overlapping region, the inner region 112b may be formed such that a notch (not shown) is formed on the side 113c of the adjacent main body portion 113. By forming the notch in main body portion 113, it is possible to make the region where inner region 112b and outer region 112c overlap each other wider. This makes it possible to more reliably prevent the inner region 112b and the outer region 112c from becoming a continuous punched region when the punching accuracy is reduced, and to more suitably suppress the occurrence of burrs and the like.

  In step B6, the outer region 112c is formed, and at the same time, the region of the main body 113 is punched out (see FIG. 8B). Thereby, a processed body PB in which the annular portion 111, the magnet housing area 112, the main body portion 113, and the connecting portion 115 are formed is obtained.

  Then, after the steps B1 to B6, and the steps C1 and C2, a predetermined number of workpieces PB (see FIG. 2) obtained from the workpiece W are overlapped, and these pieces are fastened by caulking to thereby obtain a laminated core. R is obtained (step (D)).

  Next, the operation and effect of the above-described method for manufacturing a laminated core will be described.

  The method of manufacturing the laminated core R according to the present embodiment includes (A) a step of supplying the work plate W to the progressive die 140, and (B) punching of the work plate W by the progressive die 140, and A plurality of magnet accommodating regions 112 arranged at predetermined intervals in the direction are formed, and the width of the circumferential direction is smaller than the main body portion 113 and the main body portion 113 as a magnetic flux passage sandwiched between the respective magnet accommodating regions 112. (C) a step of forming the connecting portion 115, crushing the corresponding region 115z, which is a region corresponding to the connecting portion 115, by the progressive die 140, and work hardening the corresponding region 115z; A) stacking a plurality of processed bodies PB obtained from the plate W to be processed by performing the steps (B) and (C), and obtaining a laminated core R by fastening these.

  In the manufacturing method of the laminated core R, in the work hardening step, a region (corresponding region 115z) corresponding to the connecting portion 115 having a smaller circumferential width than the main body portion 113 is work hardened by crushing. The connecting portion 115 obtained by punching has a small width in the circumferential direction and a small area, and therefore has a low strength and is easily deformed by residual stress based on the punching load. In this regard, in the method of manufacturing the laminated core R, since the corresponding region 115z is work-hardened, the deformation of the connecting portion 115 due to the residual stress can be suppressed. As described above, according to the manufacturing method of the laminated core R, the deformation caused by the residual stress is suppressed in the laminated core R of the rotor, which is a laminated body of the processed body PB in which the plurality of magnet housing regions 112 are arranged. be able to.

  The step (C) includes a step (C1 step) of performing a crushing process on the entire corresponding area 115z by the progressive die 140. As a result, the entire area of the corresponding area 115z is work-hardened, so that the work-hardened area becomes large, and the deformation of the connecting portion 115 can be more effectively suppressed.

  The step (C) includes a step (C2 step) of crushing only one side in the circumferential direction of the corresponding area 115z by the progressive die 140. By performing the crushing process on only one side, the one side is plastically deformed, and a force is generated in a direction opposite to the one side direction. Accordingly, for example, when a residual stress is applied in one side direction, a force for canceling the residual stress is generated by the crushing process, so that the deformation of the connecting portion 115 in the direction of the residual stress can be corrected.

  In the step (B) (more specifically, the step B2 and the step B3), a plurality of steps are performed so that the inner area 112b of the magnet housing area 112 adjacent in the circumferential direction, which is an area in contact with the corresponding area 115z, is not formed at the same time. The first inner region 112x and the second inner region 112y of each magnet accommodating region 112 are formed, and the step (C) is performed in the equivalent region 115z on the side of the second inner region 112y (the region in contact with the equivalent region 115z). Includes a step of performing a crushing process with the progressive die 140 only on the magnet accommodating region 112 formed later.

  The connecting portion 115 has a residual stress based on a punching load when the magnet housing region 112 is formed. More specifically, the connecting portion 115 has a residual stress in the direction of the stamped magnet housing area 112. Here, in the punching process, if the punching area in a narrow range becomes large, the load on the progressive die 140 at the time of punching becomes large, which is not preferable. Therefore, in the present embodiment, the inner region 112b is formed in two steps (steps B2 and B3) so that the inner regions 112b of the adjacent magnet housing regions 112 are not formed at the same time. As described above, in the case where the inner region 112b of the plurality of magnet housing regions 112 is formed in a plurality of steps, the later step (the step of forming the second inner area 112y) covers the corresponding area 115z at the time of punching. The punching load increases. That is, since the area of the workpiece W receiving the punching load becomes smaller in the later process, a larger punching load is applied to the corresponding area 115z. For this reason, in the connecting portion 115, a larger residual stress exists in the direction of the magnet housing region 112 (the direction of the second inner region 112y) punched out in a later step. In this regard, by performing the crushing process on the side of the second inner region 112y in the corresponding region 115z, a force is generated in a direction opposite to the direction of the second inner region 112y. The deformation of the connecting portion 115 can be effectively corrected.

  The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. For example, in the step (C), the progressive die 140 performs the crushing process only on the side of the second inner region 112y (on the side of the magnet accommodating region 112 where the region in contact with the corresponding region 115z is formed later) in the corresponding region 115z. Although it has been described that the step includes the step of performing, the step (C) is further performed with respect to the first inner region 112x side (the magnet housing region 112 side where the region in contact with the corresponding region 115z is formed first) in the corresponding region 115z Only the step of performing the crushing process by the progressive die 140 may be included. The step of performing the crushing process only on the first inner region 112x side is performed, for example, together with the B2 step in which the first inner region 112x is formed.

  FIG. 10 is an enlarged perspective view of a connecting portion 115 according to the modification. As shown in FIG. 10, by performing the crushing process on the first inner region 112x side, a deformed portion 115c that is plastically deformed and hardened is formed only on the side of the connecting portion 115 that is in contact with the first inner region 112x. . This makes it possible to generate a force that cancels out residual stress based on punching out of the magnet housing area 112 in the earlier step (the step of forming the first inner area 112x) of the two steps of forming the inner area 112b. This makes it possible to appropriately correct not only the punching of the subsequent step (the step of forming the second inner region 112y) but also the deformation of the connecting portion 115 based on the punching of the previous step.

  It has been described that the crushing process is performed only on one side of the equivalent region 115z in the C2 step after the crushing process is performed on the entire region of the corresponding region 115z in the C1 step, but is not limited thereto. The crushing process may be performed in a process subsequent to the crushing process on only one side. In addition, only one of the crushing processes of the C1 step and the C2 step may be performed. That is, only the crushing processing may be performed on the entire area of the corresponding area 115z, or only the crushing processing may be performed on only one side of the corresponding area 115z.

  Although it has been described that the crushing process is performed on the corresponding region 115z that becomes the connecting portion 115 after the punching process, the present invention is not limited to this. For example, after the above B6 step (that is, after the connecting portion 115 is formed), the connecting portion 115z is formed. 115 may be subjected to a crushing process. As described above, the “region corresponding to the connection portion 115” in the embodiment includes not only the corresponding region 115z but also the connection portion 115 itself.

  11: cylindrical portion, 12: magnet housing space, 13: main body portion, 15: connecting portion, 112: magnet housing region, 112b: inner region, 112x: first inner region, 112y: second inner region, 113: main body portion Reference numerals 115, connecting portions, 115z, equivalent area, 140, progressive die, PB, processed body, R, laminated iron core, W, plate to be processed.

Claims (5)

(A) a step of supplying a work plate to a mold;
(B) punching of the plate to be processed by the mold to form a plurality of magnet housing areas arranged at predetermined intervals in a circumferential direction, and a main body as a magnetic flux passage sandwiched between the magnet housing areas; Forming a portion and a connecting portion having a smaller width in the circumferential direction than the main body portion;
(C) a step of crushing a corresponding area, which is an area corresponding to the connection portion, by the mold, and work hardening the corresponding area;
(D) stacking a plurality of workpieces obtained from the plate to be processed by performing the steps (B) and (C), and obtaining a laminated iron core by fastening them;
Only including,
In the step (B), the regions of the magnet housing regions adjacent to each other in the circumferential direction that are in contact with the corresponding regions are divided into a plurality of steps so that the regions that are in contact with the corresponding regions are not formed at the same time. method for producing a product layer core to form.   The method for manufacturing a laminated core according to claim 1, wherein the step (C) includes a step of crushing the entire corresponding area by the mold.   3. The method for manufacturing a laminated core according to claim 1, wherein the step (C) includes a step of crushing only one side of the corresponding area in the circumferential direction by the mold. 4. Before SL (C) step, the at equivalent region, the corresponding region in contact area with respect to the magnet receiving area side formed after only comprises performing crushing work by the mold, according to claim 1 to 3 The method for producing a laminated iron core according to any one of the above. 5. The step (C) includes a step of performing the crushing process by the mold only on the magnet housing region side in which the region in contact with the corresponding region in the corresponding region is formed first. 6. The method for producing a laminated iron core according to any one of the above .

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