Method for manufacturing iron core sheet
By clamping the outer peripheral edge of the iron chip in the radially inner side before punching to form and connect it, the problem of iron chip deformation is solved, the shape accuracy and strength of the iron chip are improved, and the performance of the motor is ensured.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- AISIN CORP
- Filing Date
- 2025-10-17
- Publication Date
- 2026-04-17
AI Technical Summary
In existing technologies, the area surrounded by the magnet hole and the outer edge of the iron chip is prone to deformation during the punching process, resulting in reduced strength and insufficient shape accuracy.
Before punching, the outer peripheral edge of the iron chip is held radially inward by the die and the die to form the outer peripheral edge. The formed outer peripheral edge is then connected in the circumferential direction to avoid punching this area and reduce deformation.
It effectively suppresses the deformation of iron chips during the punching process, improves shape accuracy and strength, and ensures the stable performance of the motor.
Smart Images
Figure CN121886853A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for manufacturing iron chips. Background Technology
[0002] Previously, techniques were known for manufacturing laminated iron cores for electric motors and the like by stacking multiple iron wafers. Multiple magnet holes for mounting permanent magnets are formed near the outer periphery of each iron wafer. However, the bridge between the outer periphery of the iron wafer and the magnet holes can sometimes be narrow and weak. Therefore, when the iron wafer is punched from the workpiece after the magnet holes are formed, this bridge experiences significant stress, potentially causing deformation of the iron wafer. Consequently, techniques to suppress iron wafer deformation have been proposed in the past. For example, Patent Document 1 discloses a technique in which, in a punching method for an iron chip (11) having a bridge portion (13) between the outer radial end (12a) of the magnet insertion hole (10) and the outer region (12) of the iron chip (11), a step of forming a through hole (22) is performed before the step of punching the iron chip (11), the through hole (22) forming the outer radial contour (13d) of the bridge portion (13) (claim 1 of Patent Document 1, paragraph
[0017] of the specification and...). Figure 1 (A)). Therefore, the bridge is not prone to torsion, thereby preventing deformation of the iron chip or a decrease in its strength, maintaining the shape accuracy of the rotor core, and not causing a decrease in motor characteristics (paragraph
[0017] of the specification of Patent Document 1). The bridge (13) is not prone to deflection because the torque A applied to the bridge (13) when forming the magnet insertion hole (10) and the torque B applied to the bridge (13) when punching the through hole (22) are in opposite directions and thus cancel each other out (paragraphs
[0031] ,
[0032] of the specification of Patent Document 1). Figure 1 (B) and Figure 2 (B)). Patent documents
[0003] Patent Document 1: Patent No. 6301822 Summary of the Invention
[0004] Here, the area surrounded by the magnetic hole and the outer edge of the iron chip is more prone to deformation when punching the final iron chip compared to the area without the magnetic hole.
[0005] However, in the technology of Patent Document 1, only the outer contour of the bridge portion in the radial direction is formed in the through hole forming process, so it can suppress the deformation caused by the torsion of the bridge portion, but it cannot suppress the deformation of the area surrounded by the magnet hole and the outer peripheral edge of the iron chip.
[0006] The present invention was made in view of the above-mentioned problems, and its object is to provide a technique for suppressing deformation of an iron chip in a region surrounded by a magnetic hole and the outer peripheral edge of the iron chip.
[0007] To achieve the above objectives, the method for manufacturing an iron chip is a method for manufacturing an iron chip based on a plate-shaped component forming a laminated iron core and having a plurality of magnetic holes arranged circumferentially. The method includes a magnetic hole forming step, in which the plurality of magnetic holes are formed in the plate-shaped component while the component is held by a stripper and a die, the component having opposing long sides and short sides connecting the two ends of the long sides and shorter than the long sides, and the circumferential length of the long sides being longer than their radial length; a magnetic hole forming step, in which the region surrounded by the position of the long side and the outer peripheral edge of the iron chip is defined as the region of interest, and the outer peripheral edge of the iron chip is formed in at least a portion of the outer peripheral edge of the region of interest, excluding the circumferential ends, while the component is held radially inward by the stripper and the die; and a punching step, in which the outer peripheral edges of the iron chip formed in the outer peripheral edge forming step are punched to connect the outer peripheral edges of the iron chip formed in the outer peripheral edge forming step within the plurality of regions of interest in the circumferential direction.
[0008] That is, in the method for manufacturing iron chips, before the punching process of the iron chips, there is an outer peripheral edge forming process in which the outer peripheral edge of the iron chip is formed in at least a portion of the outer peripheral edge of the region of interest, excluding the circumferential end, while the iron chip is held radially inward by a demolding device and a die. By forming the outer peripheral edge of the iron chip while the outer peripheral edge of the iron chip is held radially inward by a demolding device and a die, deformation of the iron chip in the region of interest during the outer peripheral edge forming process can be suppressed. In addition, in the punching process, the iron chips are punched in such a way that the outer peripheral edges of the iron chips formed in the outer peripheral edge forming process are connected to each other in the circumferential direction in multiple regions of interest. Therefore, in the easily deformable regions of interest, the outer peripheral edge portion of the iron chip formed in the outer peripheral edge forming process does not need to be punched, thereby suppressing deformation in the region of interest during the punching process.
[0009] Therefore, it is possible to suppress deformation of the iron chip in the region surrounded by the magnet hole and the outer peripheral edge of the iron chip. Attached Figure Description
[0010] Figure 1 This is a top view of the iron chip. Figure 2 To enlarge Figure 1 Top view of section A. Figure 3 A flowchart illustrating the manufacturing process of iron chips. Figure 4 A is for display Figure 3 The state of the area of interest after step S120 is magnified. Figure 2 Top view of section B. Figure 4 B is for display. Figure 3 Step S130 involves enlarging the outer peripheral edge of the punch. Figure 2 Top view of section B. Figure 4 C is for display Figure 3 The state of the area of interest after step S130 is magnified. Figure 2 Top view of section B. Figure 5A for Figure 3 A schematic cross-sectional view of the mold before molding in step S120. Figure 5B for Figure 3 A schematic cross-sectional view of the mold after molding in step S120. Figure 6A for Figure 3 A schematic cross-sectional view of the mold before molding in step S130. Figure 6B for Figure 3 A schematic cross-sectional view of the mold after molding in step S130. Figure 7 This is a schematic diagram illustrating the deformation state of iron chips during existing outer diameter stamping. Detailed Implementation
[0011] Here, one embodiment of the method for manufacturing iron chips will be described in the following order. (1) Structure of iron chips: (2) Manufacturing sequence of iron chips: (3) Other implementation methods:
[0012] (1) Structure of iron chips: Figure 1 This is a top view of the iron chip involved in one embodiment. Figure 2 To enlarge Figure 1 Top view after section A in the image.
[0013] Laminated iron cores used in rotors of electric motors, etc., are manufactured by stacking multiple laminations 100. Each lamination 100 is manufactured based on a plate-shaped component 10 (see reference). Figure 3 That is, the iron chip 100 is manufactured by processing the plate-shaped component 10. Here, the structure of the manufactured iron chip 100 will be described.
[0014] The iron chip 100 is formed in a generally annular shape, having an outer peripheral edge 101 that is generally circular and an inner peripheral edge 102 that is generally circular with a smaller diameter than the outer peripheral edge 101. It should be noted that, in this specification, the center of the circle formed on or intended to be formed on the outer peripheral edge 101 or the inner peripheral edge 102 of the plate-like member 10 is referred to as the axis of rotation Ax, and the direction parallel to the axis of rotation Ax is referred to as the axial direction. Furthermore, the direction along the circumference of the circle centered on the axis of rotation Ax is referred to as the circumferential direction, and the direction parallel to the radius of that circle is referred to as the radial direction.
[0015] The iron chip 100 has a plurality of magnetic holes formed circumferentially on the plate-shaped member 10. The plurality of magnetic holes are configured such that groups G1 comprising a certain number of magnetic holes are formed on the plate-shaped member 10 in multiple sets arranged circumferentially. In this embodiment, each group G1 includes a group C1 consisting of two circumferentially adjacent magnetic holes C1a and C1b, and a group C2 consisting of three circumferentially adjacent magnetic holes C2a, C2b, and C2c formed closer to the radially inner side than group C1. Therefore, groups C1 are formed on the plate-shaped member 10 in multiple sets arranged circumferentially. Group C2 is formed to surround the radially inner side of group C1. In each group C1, a radially extending bridge portion B1 is formed between adjacent magnetic holes C1a and C1b. The bridge portion B1 is a portion formed between adjacent magnetic holes C1a and C1b that is narrower than other portions.
[0016] Each magnet hole C1a, C1b, C2a, C2b, and C2c in the magnet hole group G1 has a relatively long side a1 and a short side b1 that connects the two ends of the long side a1 and is shorter than the long side a1. (As described later...) Figure 4 As shown in Figure A, the circumferential length H1 of the long side a1 is longer than the radial length H2 of the long side a1. In this embodiment, the magnet holes C1a and C1b are formed into approximately quadrilaterals. Furthermore, the magnet holes C1a and C1b are arranged in a gently sloping, approximately V-shaped configuration where the distance between the outer peripheral edge 101 of the region of interest A1 and the closest portion C1c (described later) is minimized, while the distance between the outer peripheral edge 101 of the region of interest A1 and the radially outer end of the bridge portion B1 is maximized. It should be noted that the shape, arrangement, and number of the magnet holes formed by the long side a1 and the short side b1 can be arbitrarily set.
[0017] (2) Manufacturing sequence of iron chips: Figure 3 A flowchart illustrating the manufacturing process of iron chips. Figure 4 A is for display Figure 3 The surrounding state of the area of interest A1 after step S120 is magnified. Figure 2 Top view of section B. Figure 4 B is for display. Figure 3Step S130's punching line is enlarged. Figure 2 Top view of section B. Figure 4 C is for display Figure 3 The magnified view of the surrounding state of the area of interest A1 after step S130. Figure 2 Top view of section B. Figure 5A for Figure 3 A schematic cross-sectional view of the mold before molding in step S120. Figure 5B for Figure 3 A schematic cross-sectional view of the mold after molding in step S120. Figure 6A for Figure 3 A schematic cross-sectional view of the mold before molding in step S130. Figure 6B for Figure 3 A schematic cross-sectional view of the mold after molding in step S130.
[0018] First of all, Figure 5A as well as Figure 5B The structure of the mold 200 shown will be described. The mold 200 includes an upper mold 201 and a lower mold 202. The upper mold 201 includes a punch P3 that protrudes downward in the vertical direction for punching the inner peripheral edge 102 of the ferrite chip 100, a punch P4 that protrudes downward in the vertical direction for punching the outer peripheral hole 103, and a demolding device ST3 that pushes the plate-shaped member 10 upward in the vertical direction by the pushing force of a spring. The lower mold 202 includes a die D3 that supports the pushing force generated by the demolding device ST3 downward in the vertical direction. The demolding device ST3 and the die D3 clamp the radially inner and radially outer sides of the outer peripheral edge 101 (the predetermined forming position of the outer peripheral edge 101) of the ferrite chip 100 in the plate-shaped member 10. The radially inner side of the outer peripheral edge 101 of the ferrite chip 100 refers to the area that clamps the radially inner side of the outer peripheral edge 101 while ensuring the minimum clearance required for punching the outer peripheral hole 103. The radial outer side of the outer peripheral edge 101 of the clamping iron chip 100 refers to the area on the radial outer side of the outer peripheral edge 101 that is clamped while ensuring the minimum clearance required for the punched outer peripheral hole portion 103.
[0019] Next, for Figure 6A and Figure 6BThe structure of the mold 300 shown will be described. The mold 300 includes an upper mold 301 and a lower mold 302. The upper mold 301 includes a punch P5 that protrudes downward in the vertical direction and is used to punch the outer peripheral edge 101 of the ferrite chip 100, and a ejector ST4 that pushes the plate-shaped member 10 upward in the vertical direction by the pushing force of a spring. The lower mold 302 includes a die D4 that supports the pushing force generated by the ejector ST4 downward in the vertical direction. The ejector ST4 and the die D4 clamp the radially outer portion of the outer peripheral edge 101 of the plate-shaped member 10. Since no die is provided below the punch P5 in the vertical direction, the pushing force from the upper vertical direction of the punch P5 is not supported from the lower vertical direction, thereby pressing the outer peripheral edge 101 of the ferrite chip 100 (… Figure 4 The radially inner edge portions L2 of the outer peripheral hole portion 103 shown in C are punched between each other (L1).
[0020] It should be noted that it is also possible to hold the inner side of the outer peripheral edge 101 of the iron chip 100 by the mold releaser and the die, and punch the outer side of the outer peripheral edge 101 of the iron chip 100 by the punch. However, in this case, as will be described later, it is impossible to swage the punched iron chips 100 together. Therefore, in this embodiment, the outer side of the outer peripheral edge 101 of the iron chip 100 is held by the mold releaser ST4 and the die D4, and punching is not performed by the punch P5 from the inner side of the outer peripheral edge 101 of the iron chip 100 supported from below in the vertical direction.
[0021] Reference Figure 3 The manufacturing process of iron-containing chips is explained here. For example... Figure 4 As shown in Figure A, in this embodiment, the area surrounded by the long sides a1 of the magnet holes C1a and C1b and the outer peripheral edge 101 of the iron chip 100 is designated as the area of interest A1. The surrounded area does not necessarily mean a completely closed area relative to the outside of the surrounded area; it can also be a partially open area relative to the outside of the surrounded area. The processing steps in each process are performed while the coil-shaped plate member 10 is pulled out. It should be noted that in... Figure 3 In the middle, the plate-shaped component 10 is marked with a symbol passing through the rotation axis Ax (see reference). Figure 1 The vertical, horizontal, and diagonal lines are merely auxiliary lines; in reality, no such lines are marked on the plate-shaped component 10, nor do they form a line shape.
[0022] First, multiple (two in this embodiment) guide holes H3 are formed in the plate-shaped component 10 for positioning in each process (step S100). Multiple (two in this embodiment) guide pins (not shown) protrude from the upper surface of the base of the mold for each process, and positioning in each process is achieved by inserting the multiple guide pins into the multiple guide holes H3.
[0023] Here, as Figure 6B As shown, in step S130 described later, each of the punched iron chips 100 has a plurality of (eight in this embodiment) riveting protrusions D1 protruding downward from the lower surface of the iron chip 100, and a plurality of (eight in this embodiment) protrusion receiving grooves D2 formed on the upper surface of the iron chip 100 corresponding to the riveting protrusions D1. The riveting protrusions D1 are received and fitted into the protrusion receiving grooves D2 of the iron chip 100 that were manufactured earlier, and thus riveting is fixed. For the iron chip 100 that is manufactured first in the group of a plurality of iron chips 100 constituting the laminated iron core, since it needs to be separated from the last iron chip 100 manufactured in the previous group, the riveting protrusions D1 or the protrusion receiving grooves D2 are not formed. Instead, a plurality of (eight in this embodiment) protrusion receiving holes H4 are formed (step S105).
[0024] Then, with the plurality of magnet holes (predetermined formation positions of the magnet holes) C2a, C2b, C2c constituting the circumferentially arranged group C2 held by the demolding device and the die, the plurality of magnet holes C2a, C2b, C2c constituting the group C2 are formed on the plate member 10 by the punch (step S110). It should be noted that although the mold illustration is omitted, the structure / function of the punch, demolding device, and die are similar to... Figure 5A , Figure 5B , Figure 6A as well as Figure 6B The description is the same as above. That is, the mold has an upper mold and a lower mold. The upper mold has a punch that protrudes downward in the vertical direction for punching multiple magnet holes C2a, C2b, and C2c, and a demolding device that pushes the plate-shaped member 10 upward in the vertical direction by the pushing force of a spring. The lower mold has a die that supports the pushing force generated by the demolding device downward in the vertical direction. The demolding device and the die clamp around the multiple magnet holes (predetermined formation positions of the magnet holes) C2a, C2b, and C2c that constitute the group C2 arranged circumferentially in the plate-shaped member 10. Clamping around the multiple magnet holes (predetermined formation positions of the magnet holes) C2a, C2b, and C2c means clamping the area surrounding the magnet holes C2a, C2b, and C2c in a state that ensures the minimum clearance required for punching the magnet holes C2a, C2b, and C2c.
[0025] Subsequently, while the plurality of magnet holes (predetermined formation positions of the magnet holes) C1a, C1b constituting the circumferentially arranged group C1 are held by the demolding device and the die, the plurality of magnet holes C1a, C1b constituting the group C1 are formed on the plate-shaped member 10 by the punch (step S115, magnet hole forming process). It should be noted that although the mold illustration is omitted, the structure / function of the punch, demolding device, and die are similar to... Figure 5A , Figure 5B , Figure 6Aas well as Figure 6B The description is the same as above. That is, the mold has an upper mold and a lower mold. The upper mold has a punch that protrudes downward in the vertical direction for punching multiple magnet holes C1a, C1b, and a demolding device that pushes the plate-shaped member 10 upward in the vertical direction by the pushing force of a spring. The lower mold has a die that supports the pushing force generated by the demolding device downward in the vertical direction. The demolding device and the die clamp around the multiple magnet holes (predetermined formation positions of the magnet holes) C1a, C1b that form a group C1 arranged circumferentially in the plate-shaped member 10. Clamping around the multiple magnet holes (predetermined formation positions of the magnet holes) C1a, C1b means clamping the area surrounding the magnet holes C1a, C1b while ensuring the minimum clearance required for punching the magnet holes C1a, C1b.
[0026] Then, at a position adjacent to the radially inner side of the group of magnet holes G1 arranged circumferentially, through... Figure 5A as well as Figure 5B The punch P3 shown cuts out the inner peripheral edge 102 (refer to...) Figure 1 , Figure 2 In the state where the iron chip 100 is held radially inward by the demolding device ST3 and the punch D3 at the outer peripheral edge 101 (the predetermined forming position of the outer peripheral edge 101) (refer to...), Figure 5A , Figure 5B In at least a portion (in this embodiment, all) of the portion P2 of the outer peripheral edge 101 of the region of interest A1, excluding the circumferential end P1 (refer to...) Figure 4 A) Forming the outer peripheral edge 101 of the iron chip 100 (step S120, outer peripheral edge forming process). In this embodiment, as... Figure 5B As shown, a through peripheral hole 103 is punched out by a punch P4, adjacent to the radially outer side of the outer peripheral edge 101 of the iron chip 100. The radially inner edge of the outer peripheral hole 103 forms the outer peripheral edge 101 of the iron chip 100. By forming the outer peripheral edge 101 of the iron chip 100 while it is held radially inner by the ejector ST3 and the die D3, deformation of the iron chip 100 in the region of interest A1 during the outer peripheral edge forming process can be suppressed.
[0027] like Figure 4 A and Figure 4As shown in B, the circumferential length of the outer peripheral edge 101 of the iron chip 100 formed in the outer peripheral edge forming process is more than half (in this embodiment, the entire length) of the portion P2 of the outer peripheral edge 101 of the region of interest A1, excluding the circumferential end P1. Therefore, before the blanking process spanning a long section, the outer peripheral edge 101 is pre-formed while the outer peripheral edge 101 (at its predetermined forming position) of the iron chip 100 is held radially inward by the ejector ST3 and the die D3, thus improving the effect of suppressing deformation in the region of interest A1 during the blanking process.
[0028] like Figure 4 A and Figure 4 As shown in Figure B, the outer peripheral edge 101 of the iron chip 100 formed in the outer peripheral edge forming process includes the outer peripheral edge 101 of the iron chip 100 radially outside the bridge portion B1. Therefore, by forming the outer peripheral edge 101 of the iron chip 100 in advance in the radially outside of the bridge portion B1, deformation of the bridge portion B1 in the punching process can be suppressed.
[0029] like Figure 4 A and Figure 4 As shown in Figure B, the outer peripheral edge 101 of the iron chip 100 formed in the outer peripheral edge forming process includes the outer peripheral edge 101 of the iron chip 100 radially outside the closest portion C1c, which is closest to the magnet holes C1a and C1b. Therefore, by forming the outer peripheral edge 101 of the iron chip 100 in advance radially outside the closest portion C1c, deformation around the closest portion C1c in the punching process can be suppressed.
[0030] After step S120, multiple (eight in this embodiment) punches are used to press the portion corresponding to the iron chip, thereby simultaneously forming a riveting protrusion D1 protruding from the lower surface of the iron chip 100 and a protrusion receiving groove D2 recessed from the upper surface of the iron chip 100 (step S125). It should be noted that, as mentioned above, the first group of iron chips 100 manufactured in the group constituting the laminated iron core has a protrusion receiving hole H4, and therefore the riveting protrusion D1 and the protrusion receiving groove D2 are not formed.
[0031] Finally, as Figure 2 , Figure 4 A and Figure 4 As shown in C, the iron chip 100 is punched out in such a way that the radially inner edge portions L2 of the outer peripheral hole portions 103 constituting the outer peripheral edge 101 of the iron chip 100 formed in the outer peripheral edge forming process are connected in the circumferential direction to each other (step S130, punching process). At this time, as Figure 4As shown by the blanking line P6 of B, the outer peripheral edge of the punch P5 is offset radially outward relative to the radially inner edge of the outer peripheral hole 103 within the range of the circumferentially extending outer peripheral hole 103. This prevents secondary cutting of the plate-shaped member 10. The result after blanking is as follows... Figure 4 As shown in Figure C, in the radially inner edge portion L2 of the outer peripheral hole portion 103, between each other L1, the outer peripheral edge 101 is formed by the punching line P6 formed by the outer peripheral edge of the punch P5 in the punching process. The punched iron chip 100 is stacked in a riveted state as described above, and after a certain number of stacks, it is conveyed to the next process.
[0032] As described above, according to this embodiment, the following effects can be achieved. In existing manufacturing methods that do not include the peripheral edge forming process described above, the iron chip 100 needs to be punched from the plate-shaped part 10 with the magnet holes C1a and C1b formed therein during the punching process. In this case, as Figure 7 As shown, if the outer peripheral edge 101 of the iron chip 100 is punched by the punch P5, the area (area of interest A1) surrounded by the magnet holes C1a, C1b and the outer peripheral edge 101 of the iron chip 100 may deform in a downward bending manner. To address this, in this embodiment, a peripheral edge forming process is performed to form the outer peripheral edge 101 of the iron chip 100 at at least a portion of the portion P2 of the outer peripheral edge 101 of the area of interest A1, excluding the circumferential end P1. Following this process, in the punching process, the iron chip 100 is punched in such a way that the outer peripheral edges 101 of the iron chips 100 formed in the peripheral edge forming process in the plurality of areas of interest A1 are connected to each other in the circumferential direction. Therefore, in the area of interest A1 where deformation is likely to occur, the portion of the outer peripheral edge 101 formed in the peripheral edge forming process does not need to be punched, thereby suppressing deformation in the area of interest A1 during the punching process. Therefore, it is possible to suppress deformation of the iron chip 100 in the region (region of interest A1) surrounded by the magnet holes C1a, C1b and the outer peripheral edge 101 of the iron chip 100.
[0033] Furthermore, as in this embodiment, when the magnet holes C1a and C1b are located near the outer peripheral edge 101 of the iron chip 100, the bridge portion B1 may elongate or warp during the blanking process, adversely affecting its strength and shape. This is because during the blanking process, the product side of the plate-shaped member 10, i.e., the radially inner side of the outer peripheral edge 101 of the iron chip 100, cannot be clamped and supported, and the tensile stress generated by blanking may concentrate in the bridge portion B1. In this embodiment, with the radially inner side of the outer peripheral edge 101 of the iron chip 100 clamped by the demolding device ST3 and the die D3, the outer peripheral edge 101 of the iron chip 100 is formed in at least a portion of the portion P2 of the outer peripheral edge 101 of the region of interest A1, excluding the circumferential end P1. Then, the outer diameter of the iron chip 100 is blanked in the blanking process. As a result, the blanking force is not transmitted to the bridge portion B1 during the blanking process, reducing the stress on the bridge portion B1 and suppressing deformation.
[0034] (3) Other implementation methods: The above-described embodiment is an example of implementing the present invention, and various other embodiments are also possible. For example, in the above embodiment, the outer peripheral edge forming process is performed after the magnet hole forming process, followed by the punching process. However, the present invention can also be applied even if one of the two processes (magnet hole forming process and outer peripheral edge forming process) is performed first, followed by the other, or if both of the two processes are performed simultaneously, followed by the punching process. In the outer peripheral edge forming process, the position of the long side refers to the position of the long side of the already formed magnet hole when the magnet hole has already been formed, and refers to the position of the long side of the magnet hole to be formed when the magnet hole has not yet been formed.
[0035] Furthermore, in the above embodiment, the region surrounded by the position of the long side a1 and the outer peripheral edge 101 of the iron chip 100 is designated as the region of interest A1 (refer to...). Figure 1 as well as Figure 4A). Furthermore, suppose that two magnet holes C1a and C1b are arranged circumferentially, and two long sides a1 are arranged circumferentially. In this case, the area surrounded by the two long sides a1 and the outer peripheral edge 101 of the iron chip 100 is considered a region of interest A1. However, it is also possible to consider the area surrounded by one long side a1 and the outer peripheral edge 101 of the iron chip 100 as a region of interest, and the area surrounded by the other long side a1 and the outer peripheral edge 101 of the iron chip 100 as another region of interest. Additionally, when only one magnet hole is formed, the area surrounded by one long side a1 and the outer peripheral edge 101 of the iron chip 100 can be considered region of interest A1. Furthermore, when three magnet holes are arranged circumferentially side-by-side, and three long sides a1 are arranged circumferentially side-by-side, the area surrounded by each long side a1 and the outer peripheral edge 101 of the iron chip 100 can be considered an independent region of interest, or the area surrounded by the line segment connecting three or more long sides arranged circumferentially side-by-side and the outer peripheral edge 101 of the iron chip 100 can be considered a region of interest.
[0036] Furthermore, in the above embodiment, it is assumed that in the outer peripheral edge forming process, the outer peripheral edge 101 of the iron chip 100 is formed entirely in the portion P2 of the outer peripheral edge 101 of the region of interest A1, excluding the circumferential end P1. However, even if it is assumed that the outer peripheral edge 101 of the iron chip 100 is formed in at least a portion of the portion P2 of the outer peripheral edge 101 of the region of interest A1, excluding the circumferential end P1, the present invention can still be applied. Additionally, in the outer peripheral edge forming process, the outer peripheral edge 101 of the iron chip 100 may also be formed by including at least the central portion of the outer peripheral edge 101 of the region of interest A1 in the circumferential direction.
[0037] Furthermore, in the above embodiment, the structure is configured as follows: In this embodiment, multiple groups of magnet holes G1 are arranged circumferentially on the plate-shaped member 10, thereby constituting multiple magnet holes formed circumferentially on the plate-shaped member 10. Each group of magnet holes G1 includes a group C1 consisting of two circumferentially adjacent magnet holes C1a and C1b, and a group C2 consisting of three circumferentially adjacent magnet holes C2a, C2b, and C2c, which are formed closer to the radially inner side than group C1. However, even if the multiple magnet holes formed circumferentially on the plate-shaped member 10 do not have group C2, and multiple groups of group C1 are arranged circumferentially on the plate-shaped member 10, the present invention can still be applied.
[0038] Furthermore, in the above embodiment, it is assumed that during the outer peripheral edge forming process, a through peripheral hole 103 is formed adjacent to the radially outer side of the outer peripheral edge 101 of the iron chip 100, and the radially inner edge of the outer peripheral hole 103 forms the outer peripheral edge 101 of the iron chip 100, but it is not necessarily required to form a through hole. For example, the die can be passed through while the product is held by the ejector and the punch to perform punching, and then the product can be pushed back into the original material by the ejector.
[0039] Furthermore, the number of magnet holes in the magnet hole forming process is not limited to the number shown in the above embodiment. In the above embodiment, two circumferentially adjacent magnet holes C1a and C1b are arranged circumferentially on the plate member 10, but three or more circumferentially adjacent magnet holes may also be arranged circumferentially on the plate member 10. Alternatively, a single magnet hole may be formed instead of two circumferentially adjacent magnet holes C1a and C1b.
[0040] Furthermore, in the magnet hole forming process, the shape of the magnet hole is not limited to the above-described embodiment, and various shapes can be adopted. That is, each magnet hole C1a, C1b, C2a, C2b, and C2c in the magnet hole group G1 only needs to have a relatively long side a1 and a short side b1 that connects the two ends of the long side a1 and is shorter than the long side a1. As long as the long side and the short side connecting the two ends of the long side can be identified, the shape formed by the long side and the short side can be any shape. For example, each magnet hole C1a, C1b, C2a, C2b, and C2c in the magnet hole group G1 can be approximately rectangular, and the long side a1 and the short side b1 in each magnet hole C1a, C1b, C2a, C2b, and C2c in the magnet hole group G1 can also be formed as arcs. In addition, in each of the magnet holes C1a, C1b, C2a, C2b, and C2c of the magnet hole group G1, the lengths of the opposite long sides a1 and the lengths of the opposite short sides b1 do not need to be the same. They can be approximate trapezoids in which one long side a1 is longer than the other long side a1, or in approximate trapezoids in which one short side b1 is longer than the other short side b1.
[0041] Furthermore, in the magnet hole forming process, the arrangement of the magnet holes is not limited to the above-described embodiment, and various arrangements can be adopted. For example, in the above embodiment, the magnet holes C1a and C1b are arranged in a gently sloping, approximately V-shaped manner that extends towards the outer peripheral edge 101, but they can also be arranged in a straight line. In addition, the magnet holes C1a and C1b can also be arranged such that the distance between the outer peripheral edge 101 of the region of interest A1 and the nearest portion C1c remains constant along the circumferential direction (for example, the portion with a narrower width than other portions is connected throughout the entire region of the region of interest A1). Symbol Explanation
[0042] 10…plate-shaped component, 100…iron chip, 101…outer peripheral edge of iron chip, a1…long side, b1…short side, C1a, C1b…magnet hole, A1…area of interest, ST3…mold releaser, D3…die, P1…circumferential end, P2…part other than circumferential end, C1…group, B1…bridge, C1c…closest part.
Claims
1. A method for manufacturing an iron chip, comprising a method for manufacturing an iron chip based on a plate-shaped component to form a stacked iron core and having a plurality of magnetic holes arranged circumferentially, comprising: magnet hole forming step, wherein While the plate-shaped component is held around the multiple magnetic holes by the ejector and the die, the multiple magnetic holes are formed. The multiple magnetic holes have opposite long sides and short sides that connect the two ends of the long sides and are shorter than the long sides. The circumferential length of the long sides is longer than the radial length. In the outer peripheral edge forming process, the region surrounded by the position of the long side and the outer peripheral edge of the iron chip is defined as the region of interest. With the outer peripheral edge of the iron chip held radially inward by a demolding device and a die, the outer peripheral edge of the iron chip is formed in at least a portion of the outer peripheral edge of the region of interest, excluding the circumferential end; and... The punching process wherein the iron chip is punched in such a way that the outer peripheral edges of the iron chip formed in the outer peripheral edge forming process are connected to each other in a circumferential direction among a plurality of said regions of interest.
2. The method for manufacturing iron chips as described in claim 1, wherein, In the magnet hole forming process, a group consisting of two adjacent magnet holes in the circumferential direction is formed on the plate-shaped member in a manner in which multiple groups are arranged in the circumferential direction, and in each group, a bridge extending radially is formed between adjacent magnet holes.
3. The method for manufacturing iron chips as described in claim 1, wherein, The circumferential length of the outer peripheral edge of the iron chip formed in the outer peripheral edge forming process is more than half the length of the portion of the outer peripheral edge of the region of interest excluding the circumferential end.
4. The method for manufacturing iron chips as described in claim 2, wherein, The outer peripheral edge of the iron chip formed in the outer peripheral edge forming process includes the outer peripheral edge of the iron chip radially outside the bridge portion.
5. The method for manufacturing iron chips according to any one of claims 1 to 3, wherein, The outer peripheral edge of the iron chip formed in the outer peripheral edge forming process includes the outer peripheral edge of the iron chip radially outside the closest part to the outer peripheral edge of the iron chip where the magnet hole is closest to the outer peripheral edge of the iron chip.