Method for manufacturing motor core

Abstract

In the manufacturing method of the motor core of the present invention, in the core block manufacturing process, each core block is manufactured by stacking a plurality of core sheets. During the manufacturing, a peeling core sheet formed with one or more rivet holes and a plurality of non-rivet holes is stacked on the lower surface of the non-lowermost core block, a portion of the multiple rivet protrusions existing on the lower surface of the non-lowermost core block is riveted and engaged in the rivet holes, and the remaining rivet protrusions are inserted into the non-rivet holes in a non-rivet manner. Next, in the core block stacking process, the peeling core sheet is peeled off from the non-lowermost core block, and the core blocks are stacked up and down. Thus, a manufacturing method for a motor core is obtained that can make the operation of each core block easy and can stabilize the riveting force when stacking the core blocks.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a motor core. Background Art

[0002] In the manufacturing method of the laminated core described in the following patent document 1, a plurality of core structure blocks (core blocks) composed of a plurality of core structure sheets (core sheets) are formed using progressive die devices. A plurality of rivet protrusions are formed on the lower surface of each core block, and a plurality of rivet holes are formed on the upper surface of each core block. Then, these plurality of core blocks are gradually rotated at a predetermined angle and stacked (rotational stacking) to manufacture a motor core. As a result, the deviation in the thickness of each core sheet is offset, thereby suppressing the distortion of the outer shape of the motor core.

[0003] In the manufacturing method of the motor core described in the following patent document 2, a motor core having a first core block and a second core block is manufactured, the first core block is formed by stacking a plurality of electromagnetic steel plates (core sheets), and the second core block is stacked (rotationally stacked) on top of the first core block and is formed by stacking a plurality of core sheets. Positioning protrusions and positioning holes for positioning the first core block and the second core block are provided on the core sheet of the top layer of the plurality of core sheets of the first core block and the core sheet of the bottom layer of the plurality of core sheets of the second core block, respectively. This prevents the occurrence of faults between the stacked core blocks.

[0004] In the manufacturing method of a laminated core described in the following patent document 3, a plurality of core blocks (core blocks) each consisting of a plurality of core sheets are first formed, and then these plurality of core blocks are stacked (rotationally stacked) to manufacture a laminated core. In the laminated core, recesses or protrusions for riveting are respectively formed on the core sheet at the bottom of the core block located on the upper side and the core sheet at the top of the core block located on the lower side. Furthermore, a connecting member is arranged between the upper and lower adjacent core blocks, and a protrusion or recess that engages with these recesses or protrusions is formed on the connecting member. The core blocks are temporarily fixed by the connecting member, thereby preventing the core blocks from being scattered during transportation. Furthermore, when the laminated core is manufactured by rotationally stacking the core blocks, the above-mentioned connecting member is removed.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Publication No. 6-3779

[0008] Patent Document 2: Japanese Patent Application Publication No. 2018-82533

[0009] Patent Document 3: Japanese Patent Application Publication No. 2013-138579 Summary of the invention

[0010] Problem that the invention aims to solve

[0011] In the prior art described in the above-mentioned patent documents 1 and 2, a protrusion (convex part) for riveting is formed on the upper surface or the lower surface of each core block, so compared with the case where the upper surface or the lower surface of each core block is formed into a flat shape, the operation of transporting each core block to the next process becomes cumbersome. In this regard, in the prior art described in the above-mentioned patent document 3, each core block is temporarily fixed by a connecting member, thereby making the above-mentioned operation easy. However, once the concave or convex part formed on each core block and the convex or concave part formed on the connecting member are riveted and embedded, the connecting member must be removed again, so the concave or convex part of each core block will be deformed or worn. When the core blocks are rotated and stacked (riveted and stacked), these concave or convex parts are riveted and embedded again. Therefore, due to the above-mentioned deformation or wear, problems such as weakened riveting force, excessive riveting force, and inability to rivet will occur.

[0012] The present invention has been made in view of the above-mentioned facts, and an object of the present invention is to provide a method for manufacturing a motor core, which can facilitate the handling of each core block and stabilize the caulking force when stacking the core blocks.

[0013] Means used to solve problems

[0014] A first embodiment of the present invention is a method for manufacturing a motor core, wherein the motor core has a plurality of core blocks, the core blocks are composed of a plurality of core sheets, the plurality of core sheets are stacked by riveting a plurality of rivet recesses formed on the upper surface of each core sheet with a plurality of rivet protrusions formed on the lower surface of each core sheet, the plurality of core blocks are stacked up and down, and among the plurality of core blocks, the plurality of rivet recesses on the upper surface of the core block on the lower side are riveted and engaged with the plurality of rivet protrusions on the lower surface of the core block on the upper side; the method for manufacturing the motor core comprises: a core block manufacturing step, by stacking the plurality of core blocks Each of the core blocks is manufactured by using a sheet, and when manufacturing non-bottom core blocks other than the bottom core block among the core blocks, a peeling core sheet formed with one or more rivet holes and a plurality of non-rivet holes is stacked on the bottom surface of the non-bottom core block, a part of the plurality of rivet protrusions on the bottom surface of the non-bottom core block is riveted and engaged in the rivet holes, and the remaining rivet protrusions of the plurality of rivet protrusions are inserted into the non-rivet holes in a non-rivet manner; and a core block stacking step of peeling off the peeling core sheet from the non-bottom core block and stacking each of the core blocks up and down.

[0015] In addition, the up and down directions of the first form are used to conveniently indicate the direction of the product (object) of the motor core manufactured by the motor core manufacturing method of the first form of the invention, and have nothing to do with the direction when the manufacturing method is implemented or the direction when the motor core manufactured by the manufacturing method is used.

[0016] In the manufacturing method of the motor core of the first form, the manufactured motor core has a plurality of core blocks, each of which is composed of a plurality of core sheets, and the plurality of core sheets are stacked by riveting and fitting a plurality of riveting recesses formed on the upper surface of each core sheet and a plurality of riveting protrusions formed on the lower surface of each core sheet. The plurality of core blocks are stacked up and down, and the plurality of riveting recesses on the upper surface of the core block on the lower side are riveted and fitted with the plurality of riveting protrusions on the lower surface of the core block on the upper side.

[0017] In the manufacturing method of the motor core, in the core block manufacturing process, each core block is manufactured by stacking a plurality of core sheets. Furthermore, when manufacturing a non-bottom core block other than the bottom core block, a peeling core sheet formed with one or more rivet holes and a plurality of non-rivet holes is stacked on the bottom surface of the non-bottom core block, and a portion of the rivet protrusions existing on the bottom surface of the non-bottom core block is riveted into the rivet holes, and the remaining rivet protrusions existing on the bottom surface of the non-bottom core block are inserted into the non-rivet holes without being riveted. In this way, the bottom surface of the non-bottom core block with the peeling core sheet installed is flat, so that operations such as conveying to the next core block stacking process become easy.

[0018] And, in the next core block stacking process, the peeling iron core sheet is peeled off from the core block that is not the bottom layer, and the core blocks are stacked up and down. At this time, the multiple riveting recesses on the upper surface of the core block on the lower side are riveted and engaged with the multiple riveting protrusions on the lower surface of the core block on the upper side. A part of the riveted protrusions among the above-mentioned multiple riveted protrusions are riveted and engaged in the riveting holes of the peeling iron core sheet, and the riveted protrusions of the remaining part of the above-mentioned multiple riveted protrusions are inserted into the non-riveted holes of the peeling iron core sheet in a non-riveted manner. Therefore, the riveted protrusions of the remaining part are riveted and engaged with the riveted recesses without being deformed or worn due to the riveting. Thereby, the riveting force when stacking the core blocks can be stabilized.

[0019] The second form of the invention is a method for manufacturing a motor core. In the method for manufacturing a motor core of the first form, in the core block manufacturing process, when manufacturing the bottom core block, a cut iron core sheet formed with a plurality of rivet holes is stacked on the bottom surface of the bottom core block, and the plurality of rivet protrusions existing on the bottom surface of the bottom core block are rivet-engaged in the plurality of rivet holes of the cut iron core sheet. In the core block stacking process, the non-bottom core block after the peeling iron core sheet has been peeled off is stacked on the upper side of the bottom core block on which the cut iron core sheet is stacked.

[0020] In the manufacturing method of the motor core of the second form, in the core block manufacturing process, when manufacturing the core block of the lowest layer, the cut iron core sheet formed with multiple rivet holes is stacked on the lower surface of the core block of the lowest layer, and the multiple rivet protrusions existing on the lower surface of the core block of the lowest layer are riveted and engaged in the multiple rivet holes of the cut iron core sheet. In this way, the lower surface of the core block of the lowest layer with the cut iron core sheet installed is flat, so that the operation when conveying to the next core block stacking process becomes easy. And, in the next core block stacking process, the non-lowermost core block after the peeling iron core sheet has been peeled off is stacked on the upper side of the core block of the lowest layer with the cut iron core sheet stacked on the lower surface. In this way, a motor core in which the rivet protrusion does not protrude from the lower surface can be manufactured.

[0021] The third form of the invention is a method for manufacturing a motor core. In the method for manufacturing a motor core of the first form, in the core block manufacturing process, when manufacturing the bottom core block, the bottom peeling iron core sheet of the peeling iron core sheet formed with one or more rivet holes and multiple non-rivet holes is stacked on the lower surface of the bottom core block, a part of the multiple rivet protrusions existing on the lower surface of the bottom core block is riveted and engaged in the rivet holes of the bottom peeling iron core sheet, and the remaining part of the rivet protrusions are inserted into the non-rivet holes of the bottom peeling iron core sheet in a non-rivet manner. In the core block stacking process, the non-bottom core block after the peeling iron core sheet has been peeled off is stacked on the upper side of the bottom core block on which the bottom peeling iron core sheet is stacked.

[0022] In the manufacturing method of the motor core of the third embodiment, in the core block manufacturing process, when manufacturing the core block of the lowest layer, the lowest layer of peeling core sheets formed with one or more rivet holes and multiple non-rivet holes are stacked on the lower surface of the core block of the lowest layer, and a part of the rivet protrusions existing on the lower surface of the core block of the lowest layer are riveted and fitted in the rivet holes of the peeling core sheets of the lowest layer, and the remaining rivet protrusions existing on the lower surface of the core block of the lowest layer are inserted into the non-rivet holes of the peeling core sheets of the lowest layer without riveting. In this way, the lower surface of the core block of the lowest layer with the peeling core sheets installed is flat, so that the operation of conveying to the next core block stacking process becomes easy. In addition, in the next core block stacking process, the non-lowermost core block after the peeling core sheets have been peeled off is stacked on the upper side of the core block of the lowest layer with the peeling core sheets stacked on the lower surface. Thus, a motor core in which the caulking protrusions do not protrude from the lower surface can be manufactured.

[0023] A fourth form of the invention is a method for manufacturing a motor core. In the method for manufacturing a motor core of any one of the first to third forms, in the core block manufacturing process, a through hole is formed on each of the core blocks to penetrate the multiple core sheets along their stacking direction, and a portion of the upper surface of the peeling core sheet stacked on the lower surface of the non-lowermost core block is made opposite to the through hole, and in the core block stacking process, an insert inserted into the through hole is made to hit the portion of the upper surface of the peeling core sheet, thereby peeling the peeling core sheet from the non-lowermost core block.

[0024] In the manufacturing method of the motor core of the fourth form, in the core block manufacturing process, a through hole is formed on each core block to penetrate multiple core sheets along the stacking direction thereof. In addition, a portion of the upper surface of the peeling core sheet stacked on the lower surface of the core block not in the lowest layer is made to face the above-mentioned through hole. In the subsequent core block stacking process, the insert inserted into the through hole is made to hit the portion of the upper surface of the peeling core sheet, thereby peeling the peeling core sheet from the core block not in the lowest layer. As a result, the operation of peeling the peeling core sheet from the core block not in the lowest layer becomes easy.

[0025] The fifth form of the invention is a method for manufacturing a motor core. In the method for manufacturing a motor core of any one of the first to third forms, in the core block manufacturing process, the multiple rivet recesses and the multiple rivet protrusions are arranged along the circumferential direction of each of the core pieces and formed on each of the core pieces, and the two rivet holes and the multiple non-rivet holes are arranged along the circumferential direction of the stripping core piece and formed on the stripping core piece.

[0026] In the manufacturing method of the motor core of the fifth form, in the core block manufacturing process, a plurality of riveting recesses and a plurality of riveting protrusions are arranged along the circumferential direction of each core sheet and formed on each core sheet. In addition, two riveting holes for riveting and fitting with a part of the plurality of riveting protrusions existing on the lower surface of the core block and non-riveting holes for inserting the remaining riveting protrusions without riveting are arranged along the circumferential direction of the peeling core sheet and formed on the peeling core sheet. Thus, in the subsequent core block stacking process, since the two riveting protrusions can be riveted and fitted in the two riveting holes, the holding force of the peeling core sheet relative to the lower surface of the core block can be improved compared with the case where the peeling core sheet is held on the lower surface of the core block only by riveting and fitting with one riveting hole and one riveting protrusion. In addition, compared with a structure in which three or more caulking protrusions and three or more caulking holes are caulked and fitted, it is easier to peel off the peeling core sheet from the core block.

[0027] The sixth form of the invention is a method for manufacturing a motor core. In the method for manufacturing a motor core of the fifth form, when observed from the thickness direction of the peeling iron core sheet, two rivet holes are formed on the peeling iron core sheet at positions that are point-symmetrical with respect to the center of the peeling iron core sheet.

[0028] In the sixth aspect of the method for manufacturing a motor core, two rivet holes are formed on the peeling core sheet stacked on the lower surface of the core block at positions symmetrical to each other with respect to the center of the peeling core sheet when viewed from the thickness direction of the peeling core sheet. Thus, in the subsequent core block stacking step, the two rivet protrusions on the lower surface of the core block are riveted and fitted into the two rivet holes, thereby enabling the peeling core sheet to be held on the lower surface of the core block with good balance.

[0029] The seventh form of the invention is a method for manufacturing a motor core. In the method for manufacturing a motor core of any one of the first to sixth forms, in the core block manufacturing process, the number of the rivet protrusions formed on the core sheet constituting the lower surface of the core block is set to be greater than the number of the rivet recesses formed on the core sheet constituting the upper surface of the core block, and avoidance holes are formed on the upper surface of the core block, the avoidance holes allowing the set extra number of rivet protrusions to be inserted without rivet, and in the core block stacking process, the rivet protrusions riveted into the rivet holes of the peeled off peeling core sheet are inserted into the avoidance holes.

[0030] In the manufacturing method of the motor core of the seventh form, in the core block manufacturing process, the number of riveted protrusions formed on the core sheet constituting the lower surface of the core block is set to be greater than the number of riveted recesses formed on the core sheet constituting the upper surface of the core block. In addition, an escape hole is formed on the upper surface of the core block, and the escape hole allows the set extra number of riveted protrusions to be inserted without riveting. In the subsequent core block stacking process, when stacking the core blocks, the riveted protrusions riveted into the riveting holes of the peeling core sheet, that is, the riveted protrusions that are deformed or worn due to the riveting, are inserted into the above-mentioned escape holes without riveting. As a result, the riveted protrusions that are deformed or worn are embedded in the riveted recesses, so that the instability of the riveting force can be prevented.

[0031] Effects of the Invention

[0032] As described above, in the method for manufacturing a motor core of the present invention, it is possible to facilitate the handling of the core blocks and stabilize the caulking force when stacking the core blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a perspective view showing the structure of a rotor core manufactured by the method for manufacturing a motor core according to the first embodiment of the present invention.

[0034] Figure 2 It is a perspective view showing a state during the manufacturing process of the rotor core.

[0035] Figure 3A It is a top view showing the structure of the core sheet.

[0036] Figure 3B It is a side view showing the structure of the core sheet.

[0037] Figure 4 It is a top view showing the structure of a cut iron core sheet.

[0038] Figure 5 It is a top view showing the structure of the peeling core piece.

[0039] Figure 6 This is a front view showing the structure of a progressive die device used in a core block manufacturing process.

[0040] Figure 7 It is a cross-sectional view showing a partial structure of a core block to which the lowermost layer of cut core sheets is attached.

[0041] Figure 8 It is a cross-sectional view showing a partial structure of a core block to which the peeling core pieces are attached.

[0042] Fig. 9It is a perspective view showing a state when the peeling core pieces are peeled off from the core blocks.

[0043] Fig.10 It is a cross-sectional view showing a state in which the core blocks from which the peeling core pieces are peeled are stacked on the upper side of the core blocks in the lowermost layer.

[0044] Fig.11 It is a cross-sectional view showing a state in which core blocks from which the peeling core sheets are peeled are stacked on the upper side of the lowermost core blocks in the second embodiment of the present invention.

[0045] Fig.12 It is a top view showing the structure of a modified example of the peeling core piece.

[0046] Description of Reference Numerals

[0047] 10: rotor core (motor core),

[0048] 12A~12C: non-bottommost core blocks,

[0049] 12D: The bottom iron core block,

[0050] 14: Through hole,

[0051] 16: Iron chips,

[0052] 20: riveting concave part,

[0053] 21: Avoidance hole,

[0054] 22: Riveted convex part,

[0055] 24: Cutting iron chips,

[0056] 28: Riveting holes,

[0057] 30: peeling iron chips,

[0058] 32: Riveting hole,

[0059] 34: Non-riveted holes,

[0060] 52: Insert. DETAILED DESCRIPTION

[0061] First embodiment

[0062] Below, refer to Figures 1 to 10The method for manufacturing a motor core according to the first embodiment of the present invention is described. The method for manufacturing a motor core according to the present embodiment is a method for manufacturing a motor core (laminated core) for manufacturing motors for automobiles, home appliances, and other industrial fields. In addition, the up and down directions described in the following description are used to conveniently show the motor core manufactured by the method for manufacturing a motor core according to the present embodiment (as an example, refer to Figure 1 The orientation of the product of the rotor core 10) shown has nothing to do with the orientation when the manufacturing method is implemented or the orientation when the motor core manufactured by the manufacturing method is used.

[0063] Figure 1 The rotor core 10 shown has a plurality of (here, 4) core blocks 12A, 12B, 12C, and 12D each consisting of a plurality of (several) core pieces 16 and stacked in the vertical direction. The core blocks 12A to 12C are equivalent to the "core blocks not in the lowest layer" in the present invention, and the core block 12D is equivalent to the "core block in the lowest layer" in the present invention. Cut core pieces 24 are stacked on the lower surface of the core block 12D in the lowest layer. The core blocks 12A to 12D are all formed into cylindrical shapes with a relatively short dimension in the axial direction, and a through hole 14 is formed in the axial center portion of each core block 12A to 12D, which penetrates each core block 12A to 12D in the axial direction. The through hole 14 penetrates the cut core piece 24. The through hole 14 is configured to allow the rotating shaft (not shown) of the motor to be embedded. Hereinafter, the core blocks 12A to 12D may be referred to as “each core block 12 ” or simply as “core block 12 ”.

[0064] When manufacturing the rotor core 10, first, in the core block manufacturing process, each core block 12 is manufactured (see Figure 2 Then, in the core block stacking step, the core blocks 12 are stacked up and down (in the axial direction).

[0065] In the above-mentioned core block manufacturing process, when manufacturing the core block 12D of the lowest layer, a plurality of core sheets 16 (see Figure 3A and Figure 3B ) are stacked up and down, but at this time, Figure 4 A plurality of core sheets 16 are stacked sequentially on the upper side of the cut core sheet 24 shown in the figure. In addition, in the core block manufacturing process, when manufacturing the core blocks 12A to 12C other than the bottom layer (i.e., the core blocks 12 stacked at least on the upper side of the other core blocks 12), a plurality of core sheets 16 are stacked up and down, but at this time, Figure 5 A plurality of core pieces 16 are sequentially stacked on the upper side of a peel core piece 30 shown.

[0066] In the following core block stacking process, after peeling off each peeling core sheet 30 from each lower surface of the core blocks 12A to 12C, these core blocks 12A to 12C are stacked in sequence on the upper side of the lowest core block 12D. At this time, for example, the core blocks 12A to 12D are rotated and stacked. That is, the core blocks 12A to 12D are rotated step by step at a predetermined angle (for example, 90 degrees) so that the stacking phases are staggered. Next, the above-mentioned structural elements and the above-mentioned processes of the rotor core 10 are described in detail.

[0067] like Figure 3A and Figure 3B As shown, the core piece 16 is formed in a disc shape. The core piece 16 is made of electromagnetic steel plate. A circular through hole 18 is formed in the central portion of the core piece 16, and a plurality of (here 8) rivet recesses 20 and a plurality of (here 8) rivet protrusions 22 are formed on the outer peripheral side of each core piece 16. In addition, a magnet insertion hole (not shown) for inserting a permanent magnet is also formed on the core piece 16. The plurality of rivet recesses 20 are formed on the upper surface of the core piece 16, and the plurality of rivet protrusions 22 are formed on the lower surface of the core piece 16. These rivet recesses 20 and rivet protrusions 22 are formed, for example, in the form of V-riveting, half-punch riveting, etc., and each rivet protrusion 22 is located directly below each rivet recess 20. As an example, these riveted recesses 20 and riveted protrusions 22 are formed into rectangular strips with the radial direction of the core sheet 16 (radial direction of the core block 12) as the long side, and are arranged at equal intervals in the circumferential direction of the core sheet 16 (circumferential direction of the core block 12). Therefore, when viewed from the thickness direction of the core sheet 16 (axial direction of the core block 12), two riveted protrusions 22 are arranged on the core sheet 16 at positions that are point-symmetrical with respect to the center S1 of the core sheet 16 (center of the core block 12).

[0068] As an example, Figure 4 As shown, the cut core sheet 24 is formed into a disk shape having the same diameter as the core sheet 16. The material of the cut core sheet 24 is, for example, the same as that of the core sheet 16, i.e., an electromagnetic steel plate. A through hole 26 having the same diameter as the through hole 18 of the core sheet 16 is formed in the central portion of the cut core sheet 24, and a plurality of (here, 8) rivet holes 28 penetrating the cut core sheet 24 in the thickness direction are formed on the outer peripheral side of the cut core sheet 24. As an example, these rivet holes 28 are formed into a rectangular strip shape having the radial direction of the cut core sheet 24 (the radial direction of the core block 12) as the long side, and are arranged at equal intervals in the circumferential direction of the cut core sheet 24 (the circumferential direction of the core block 12). Therefore, when viewed from the thickness direction of the cut core sheet 24 (the axial direction of the core block 12), two rivet holes 28 are arranged on the cut core sheet 24 at positions symmetrical to each other with respect to the center S2 of the cut core sheet 24 (the center of the core block 12).

[0069] like Figure 5 As shown, the peeling core sheet 30 is formed into a disk shape having the same diameter as the core sheet 16. The material of the peeling core sheet 30 is, for example, the same as that of the core sheet 16, i.e., an electromagnetic steel plate. In the central portion of the peeling core sheet 30, no through hole is formed like the through hole 18 of the core sheet 16, and a plurality of (here 2) rivet holes 32 and a plurality of (here 6) non-rivet holes 34 are formed on the outer peripheral side of the peeling core sheet 30. As an example, these rivet holes 32 and non-rivet holes 34 are formed into a rectangular strip shape with the radial direction of the peeling core sheet 30 (the radial direction of the core block 12) as the long side, and are arranged at equal intervals in the circumferential direction of the peeling core sheet 30 (the circumferential direction of the core block 12). Furthermore, when viewed from the thickness direction of the peeling core sheet 30 (the axial direction of the core block 12), two rivet holes 32 are arranged at positions on the peeling core sheet 30 that are point-symmetrical with respect to the center S3 of the peeling core sheet 30 (the center of the core block 12). These rivet holes 32 are formed to have a size that allows them to be riveted and engaged with the rivet protrusions 22 of the core sheet 16, and the non-rivet holes 34 are formed to have a size that does not allow them to be riveted and engaged with the rivet protrusions 22 of the core sheet 16 (i.e., a size larger than the rivet protrusions 22).

[0070] The core piece 16, the cutting core piece 24 and the peeling core piece 30 of the above-mentioned structure are made by using, for example, Figure 6 The core block is manufactured by the progressive die device 40 shown in FIG. The above-mentioned core block manufacturing process is performed in the progressive die device 40. In the core block manufacturing process, the strip-shaped electromagnetic steel sheet (narrow strip material) ES is subjected to a preliminary punching process, an outer shape punching process, and a laminating process.

[0071] In the pre-blanking process, various blanking processes are sequentially performed on the electromagnetic steel sheet ES to form the basic shape of the iron core sheet 16, the cut iron core sheet 24 or the peeling iron core sheet 30 except for the outer shape. At this time, while the electromagnetic steel sheet ES is intermittently conveyed in the progressive die device 40, the electromagnetic steel sheet ES is sequentially blanked using a plurality of punches 44 installed in the upper die 42 that moves in the up-down direction. While performing progressive conveying, intermittent blanking processes are performed using a plurality of punches 44 installed in the upper die 42 that moves in the up-down direction. When performing this blanking process, the punching template (stripping template) 42A installed in the upper die 42 descends, thereby pressing the electromagnetic steel sheet ES against the upper surface of the lower die 46. In addition, Figure 6 The arrow T shown indicates the conveying direction of the electromagnetic steel sheet ES.

[0072] After the pre-punching process is completed, the outer shape punching process is implemented. At this time, the outer shape of the core piece 16, the cut core piece 24 or the peeling core piece 30 is punched out using the outer shape punching punch 48 installed in the upper die 42 of the progressive die device 40. After the core piece 16, the cut core piece 24 or the peeling core piece 30 is obtained through the outer shape punching process, the stacking process is implemented. Below the outer shape punching punch 48, an extrusion ring 50 is provided in the lower die 46. In the stacking process, the core pieces 16, the cut core pieces 24 or the peeling core pieces 30 punched out through the outer shape punching process are stacked in sequence in the extrusion ring 50. In this way, each core block 12 is manufactured.

[0073] Specifically, when manufacturing the lowest core block 12D, a plurality of core sheets 16 are sequentially stacked on the upper side of the cut core sheet 24 in the extrusion ring 50. Figure 7 As shown, a plurality of riveted protrusions 22 are formed on the lower surface of the lowest iron core sheet 16 among the plurality of iron core sheets 16, and the plurality of riveted protrusions 22 are riveted and engaged in a plurality of riveted holes 28 formed on the cut iron core sheet 24. In addition, at this time, between the plurality of iron core sheets 16, a plurality of riveted recesses 20 formed on each upper surface and a plurality of riveted protrusions 22 formed on each lower surface are riveted and engaged with each other. Thus, an iron core block 12D having the lowest layer of the cut iron core sheets 24 stacked (combined, held) on the lower surface is manufactured. In addition, Figure 7 , Figure 8 and Fig.10 In order to facilitate viewing of the drawings, only two core pieces 16 are shown in each core block 12. Fig.11 The same is true in Chinese.

[0074] As described above, the through hole 14D that penetrates the core block 12D and the cut core sheet 24 in the axial direction is formed at the axial center portion of the lowest layer of the core block 12D on the lower surface of which the cut core sheet 24 is stacked. The through hole 14D is composed of the through hole 18 formed in the center of each core sheet 16 and the through hole 26 formed in the center of the cut core sheet 24, and penetrates each core sheet 16 and the cut core sheet 24 in the stacking direction.

[0075] In addition, when manufacturing other core blocks 12A to 12C, a plurality of core sheets 16 are sequentially stacked on the upper side of the peeling core sheet 30 in the extrusion ring 50. Figure 8As shown, a plurality of riveted protrusions 22 are formed on the lower surface of the lowest iron core sheet 16 among the plurality of iron core sheets 16, and a portion of the plurality of riveted protrusions 22 (here, two riveted protrusions 22) are riveted and engaged in two riveted holes 32 formed on the peeling iron core sheet 30, and the remaining portion of the plurality of riveted protrusions 22 formed on the lower surface of the above-mentioned lowest iron core sheet 16 (here, six riveted protrusions 22) are inserted into six non-riveted holes 34 formed on the peeling iron core sheet 30 in a non-riveted manner. In addition, at this time, between the plurality of iron core sheets 16, the plurality of riveted recesses 20 formed on each upper surface and the plurality of riveted protrusions 22 formed on each lower surface are riveted and engaged with each other. By repeating the above operation, the iron core blocks 12A to 12C with the peeling iron core sheets 30 stacked (combined, held) on the lower surface are manufactured.

[0076] As described above, the through holes 14A to 14C that penetrate these core blocks 12A to 12C in the axial direction are formed in the axial center portion of the core blocks 12A to 12C on which the peeling core pieces 30 are stacked on the lower surface. These through holes 14A to 14C are composed of the through holes 18 formed in the central portion of each core piece 16, and penetrate each core piece 16 in the stacking direction thereof. These through holes 14A to 14C are arranged opposite to a portion (here, the central portion) of the upper surface of the peeling core piece 30 from the upper side.

[0077] The core blocks 12A to 12D manufactured as described above are discharged from the progressive die device 40 and transported to the core block stacking step as the next step. In the core block stacking step, the peeling core pieces 30 are peeled off from the core blocks 12A to 12C. Fig. 9 As shown, the insert 52 is inserted into the through hole 14 of the core blocks 12A to 12C and hits the center of the upper surface of the peeling core sheet 30 to peel the peeling core sheet 30 from the core blocks 12A to 12C. As an example, the insert 52 is formed in a rod shape.

[0078] Next, on the upper side of the lowest core block 12D on which the cut core pieces 24 are stacked, a plurality of core blocks 12A to 12C (see FIG. 1 ) are stacked in sequence (rotation stacked) after the peeling core pieces 30 are peeled off. Fig.10 At this time, the plurality of rivet recesses 20 existing on the upper surface of the lower core block 12 and the plurality of rivet protrusions 22 existing on the lower surface of the upper core block 12 are rivet-engaged with each other. Thus, the plurality of core blocks 12 are coupled to each other in the axial direction, thereby completing the rotor core 10.

[0079] (Function and Effect)

[0080] Next, the function and effect of this embodiment will be described.

[0081] In the manufacturing method of the motor core of the present embodiment, a rotor core 10 having a plurality of core blocks 12A to 12D is manufactured, each core block 12A to 12D is composed of a plurality of core sheets 16, and the plurality of core sheets 16 are stacked by riveting and fitting a plurality of riveting recesses 20 formed on each upper surface and a plurality of riveting protrusions 22 formed on each lower surface. The plurality of core blocks 12A to 12D are stacked up and down, and the plurality of riveting recesses 20 existing on the upper surface of the lower core block 12 are riveted and fitting a plurality of riveting protrusions 22 existing on the lower surface of the upper core block 12.

[0082] In this manufacturing method, in the core block manufacturing process, each core block 12A to 12D is manufactured by stacking a plurality of core sheets 16. When manufacturing the core blocks 12A to 12C that are not the lowest layer, a peeling core sheet 30 having a plurality of (here, 2) rivet holes 32 and a plurality of (here, 6) non-rivet holes 34 is stacked on the lower surface of each core block 12A to 12C, and a portion of the rivet protrusions 22 existing on the lower surface of each core block 12A to 12C is riveted and engaged in the rivet holes 32, and the remaining rivet protrusions 22 existing on the lower surface of each core block 12A to 12C are inserted into the non-rivet holes 34 without being riveted. As described above, since the lower surface of each of the core blocks 12A to 12C to which the peeling core pieces 30 are attached is flat (plane), handling when conveying to the next core block stacking step is facilitated.

[0083] In addition, in the next core block stacking process, the peeling core sheet 30 is peeled off from each core block 12A to 12C, and each core block 12A to 12C is stacked by rotating up and down. At this time, the plurality of rivet recesses 20 existing on the upper surface of the core block 12 on the lower side are riveted and engaged with the plurality of rivet protrusions 22 existing on the lower surface of the core block 12 on the upper side. A portion of the rivet protrusions 22 are riveted and engaged in the rivet holes 32 of the peeling core sheet 30, and the remaining rivet protrusions 22 are inserted into the non-rivet holes 34 of the peeling core sheet 30 in a non-riveted manner. Therefore, the remaining rivet protrusions 22 can be riveted and engaged with the rivet recesses 20 without being deformed or worn due to the riveting and engaging. As a result, the riveting force when stacking the core blocks 12A to 12C can be stabilized.

[0084] In addition, in the rotor core 10 manufactured by the present embodiment, when manufacturing the core block 12D of the lowest layer in the core block manufacturing process, the cut core sheet 24 formed with a plurality of caulking holes 28 is stacked on the lower surface of the core block 12D of the lowest layer, and the plurality of caulking protrusions 22 existing on the lower surface of the core block 12D of the lowest layer are caulked and fitted into the plurality of caulking holes 28 of the cut core sheet 24. In this way, the lower surface of the core block 12D of the lowest layer on which the cut core sheet 24 is mounted is flat, so that the operation when conveying to the next core block stacking process becomes easy. In addition, in the next core block stacking process, the plurality of core blocks 12A to 12C from which the peeling core sheet 30 has been peeled off are stacked on the upper side of the core block 12D of the lowest layer on which the cut core sheet 24 is stacked on the lower surface. In this way, the rotor core 10 in which the caulking protrusions 22 do not protrude from the lower surface can be manufactured.

[0085] In addition, in the present embodiment, in the core block manufacturing process, through holes 14A to 14C are formed in each core block 12A to 12C to penetrate the plurality of core sheets 16 in the stacking direction thereof. Furthermore, a portion of the upper surface of the peeling core sheets 30 stacked on the lower surface of each core block 12A to 12C is made to face the above-mentioned through holes 14A to 14C. In the subsequent core block stacking process, the insert 52 inserted into the through holes 14A to 14C is made to hit a portion of the upper surface of the peeling core sheets 30, thereby peeling the peeling core sheets 30 from the core blocks 12A to 12C. Thus, the operation of peeling the peeling core sheets 30 from the core blocks 12A to 12C becomes easy. In addition, in the prior art described in Patent Document 3 described in the background technology, the connecting member is riveted to both the upper and lower core blocks, so it is not easy to peel off the connecting member. However, in the present embodiment, the peeling iron core sheet 30 is only riveted to the lower surface of the core blocks 12A~12C, thereby making it easy to peel off the peeling iron core sheet 30.

[0086] In addition, when the cut core sheets 24 are stacked on the lower surfaces of the core blocks 12A to 12C, the lower surfaces of the core blocks 12A to 12C can also be formed flat. However, in this case, all the multiple (here, 8) rivet protrusions 22 existing on the lower surfaces of the core blocks 12A to 12C are riveted and engaged with all the multiple (here, 8) rivet holes 28 formed on the cut core sheets 24, so it is not easy to peel off the cut core sheets 24 from each core block 12A to 12C. In this regard, in the present embodiment, among the multiple (here, 8) rivet protrusions 22 existing on the lower surfaces of the core blocks 12A to 12C, the multiple (here, 6) rivet protrusions 22 in the non-rivet holes 34 into which the peeling core sheets 30 are inserted are not riveted and engaged with the non-insertion holes, so it is easy to peel off the peeling core sheets 30 from the core blocks 12A to 12C. As a result, the core blocks 12A to 12D can be stacked without designing a complicated process. In addition, in the present embodiment, the core blocks 16 other than the cut core sheet 24 and the peeling core sheet 30 can have the same structure, so that the core blocks 12 can be easily manufactured.

[0087] In addition, in the present embodiment, in the core block manufacturing process, a plurality of rivet recesses 20 and a plurality of rivet protrusions 22 are arranged along the circumferential direction of each core sheet 16 and formed on each core sheet 16. In addition, two rivet holes 32 for riveting and fitting with a part of the plurality of rivet protrusions 22 existing on the lower surface of the core blocks 12A to 12C and non-rivet holes 34 for inserting the remaining rivet protrusions 22 without riveting are arranged along the circumferential direction of the peeling core sheet 30 and formed on the peeling core sheet 30. Thus, in the subsequent core block stacking process, since the two rivet protrusions 22 can be rivet-fitted into the two rivet holes 32, the holding force of the peeling core sheet 30 relative to the lower surface of the core blocks 12A to 12C can be improved compared to the case where the peeling core sheet 30 is held on the lower surface of the core blocks 12A to 12C by only the rivet fitting of one rivet hole 32 and one rivet protrusion 22. In addition, compared to the structure where three or more rivet protrusions 22 are rivet-fitted into three or more rivet holes 32, the operation of peeling the peeling core sheet 30 from the core blocks 12A to 12C becomes easier.

[0088] Moreover, in the present embodiment, in the core block manufacturing process, when viewed from the thickness direction of each core sheet 16, two rivet protrusions 22 are formed on each core sheet 16 at mutually point-symmetrical positions with respect to the center S1 of each core sheet 16. Thus, on the lower surface of the core block 12 manufactured by stacking the plurality of core sheets 16, when viewed from the thickness direction of each core sheet 16 (the axial direction of the core block 12), two rivet protrusions 22 exist on each core sheet 16 at mutually point-symmetrical positions with respect to the center of the core block 12. In addition, on the peeling core sheet 30 stacked on the lower surface of the core blocks 12A to 12C, when viewed from the axial direction of the peeling core sheet 30, two rivet holes 32 are formed on the peeling core sheet 30 at mutually point-symmetrical positions with respect to the center S3 of the peeling core sheet 30. Thus, in the subsequent core block stacking step, the two caulking protrusions 22 are caulked and fitted into the two caulking holes 32 , so that the peeling core sheet 30 can be held in a balanced manner on the lower surfaces of the core blocks 12A to 12C.

[0089] In addition, in the first embodiment, the cut core sheet 24 is stacked on the lower surface of the core block 12D of the lowest layer, but the present invention is not limited to this structure, and the peeling core sheet 30 may be stacked on the lower surface of the core block 12D of the lowest layer. In this case, when manufacturing the core block 12D of the lowest layer, the peeling core sheet 30 of the lowest layer, which is formed with one or more rivet holes 32 and a plurality of non-rivet holes 34, is stacked on the lower surface of the core block 12D of the lowest layer, and a part of the rivet protrusions 22 existing on the lower surface of the core block 12D of the lowest layer is riveted and engaged with the rivet holes 32 of the peeling core sheet 30 of the lowest layer, and the remaining rivet protrusions 22 existing on the lower surface of the core block 12D of the lowest layer are inserted into the non-rivet holes 34 of the peeling core sheet 30 of the lowest layer without being riveted. Thus, the lower surface of the lowest core block 12D on which the above-mentioned lowest peeling core sheet 30 is mounted is formed into a flat shape, so that the operation when conveying to the next core block stacking process becomes easy. And in the next core block stacking process, on the upper side of the lowest core block 12D on which the peeling core sheet 30 is stacked on the lower surface, a plurality of core blocks 12A to 12C from which the peeling core sheet 30 has been peeled off are stacked in sequence. Thus, the rotor core 10 in which the rivet protrusion 22 does not protrude from the lower surface can be manufactured. In addition, the core sheets 16 other than the peeling core sheet 30 can have the same structure.

[0090] In addition, in the above-mentioned first embodiment, 8 rivet recesses 20 and 8 rivet protrusions 22 are formed on the iron core sheet 16, 8 rivet holes 28 are formed on the cutting iron core sheet 24, and 2 rivet holes 32 and 6 non-rivet holes 34 are formed on the peeling iron core sheet 30. However, this is not limited to this, and the number of rivet recesses 20, rivet protrusions 22, rivet holes 28, rivet holes 32 and non-rivet holes 34 can be appropriately changed.

[0091] <Second embodiment>

[0092] Below, refer to Fig.11 A method for manufacturing a motor core according to a second embodiment of the present invention will be described. The method for manufacturing a motor core according to the second embodiment is basically the same as the method for manufacturing a motor core according to the first embodiment except for the following differences.

[0093] In the manufacturing method of the motor core of this embodiment, in the core block manufacturing process, the number of riveted protrusions 22 formed on the core sheet 16 constituting the lower surface of the core block 12 is set to be greater than the number of riveted recesses 20 formed on the core sheet 16 constituting the upper surface of the core block 12, and avoidance holes 21 are formed on the upper surface of the core block 12, and the avoidance holes 21 can be inserted into the set excess number of riveted protrusions 22 without being riveted. In the subsequent core block lamination process, as shown in FIG. Fig.11 As shown, the rivet protrusion 22 riveted into the rivet hole 32 of the peeled peeling core sheet 30, that is, the rivet protrusion 22 deformed or worn due to the riveting engagement with the rivet hole 32, is inserted into the above-mentioned avoidance hole 21 without being riveted. Thus, the rivet protrusion 22 deformed or worn is engaged in the rivet recess 20, thereby preventing the instability of the riveting force. In other words, it is possible to prevent the rivet force of each core block 12 from becoming too strong or becoming impossible to rivet when stacking due to the deformation or wear of a part of the rivet protrusion 22.

[0094] In addition, in each of the above-mentioned embodiments, when viewed from the thickness direction of the peeling core sheet 30 (the axial direction of the core block 12), two rivet holes 32 are arranged on the peeling core sheet 30 at positions symmetrical to each other with respect to the center S3 of the peeling core sheet 30 (the center of the core block 12), but this is not limited to this. That is, for example Fig.12 As in the modified example shown, two caulking holes 32 may be arranged at positions that are not point-symmetrical with respect to the center S3.

[0095] In the above-mentioned embodiments, the rotor core 10 may be manufactured in an upside-down order. Figure 2The rotor core 10 is manufactured with the uppermost portion of the structure shown as the lowermost portion. In this case, the peeling core pieces 30 are arranged on the upper side of the core blocks 12 during manufacturing, so that the work of peeling the peeling core pieces 30 becomes easier.

[0096] In the above-mentioned embodiments, the case of manufacturing the rotor core 10 is described. However, the present invention is not limited thereto, and the method for manufacturing a motor core of the present invention can also be applied to the case of manufacturing a stator core as a motor core.

[0097] In addition, the present invention can be implemented with various modifications without departing from the gist of the present invention. In addition, the scope of rights of the present invention is not limited to the above-mentioned embodiments.

Claims

1. A method for manufacturing a motor core, wherein: The motor core has a plurality of core blocks, each core block being composed of a plurality of core sheets, each of which is stacked by riveting a plurality of rivet recesses formed on the upper surface of each core sheet with a plurality of rivet protrusions formed on the lower surface of each core sheet, wherein the plurality of core blocks are stacked up and down, and the plurality of rivet recesses on the upper surface of the core block on the lower side are riveted and engaged with the plurality of rivet protrusions on the lower surface of the core block on the upper side; The manufacturing method of the motor core comprises: A core block manufacturing process, wherein each of the core blocks is manufactured by stacking the plurality of core sheets, and when manufacturing a non-lowermost core block other than the lowermost core block among the core blocks, a peeling core sheet having one or more rivet holes and a plurality of non-rivet holes is stacked on the lower surface of the non-lowermost core block, a portion of the plurality of rivet protrusions existing on the lower surface of the non-lowermost core block is riveted and engaged in the rivet holes, and the remaining portion of the rivet protrusions is inserted into the non-rivet holes in a non-rivet manner; and The core block stacking step is to peel off the peeling core sheets from the non-lowermost core blocks and stack the core blocks up and down.

2. The method for manufacturing a motor core according to claim 1, wherein: In the core block manufacturing process, when manufacturing the bottom core block, a cut core sheet having a plurality of rivet holes is stacked on the bottom surface of the bottom core block, and the plurality of rivet protrusions on the bottom surface of the bottom core block are riveted and engaged in the plurality of rivet holes of the cut core sheet. In the core block stacking step, the non-lowermost core block from which the peeling core pieces have been peeled off is stacked on the upper side of the lowermost core block on which the cut core pieces are stacked.

3. The method for manufacturing a motor core according to claim 1, wherein: In the iron core block manufacturing process, when manufacturing the lowermost iron core block, the lowermost peeling iron core sheet in the peeling iron core sheet formed with one or more rivet holes and a plurality of non-rivet holes is stacked on the lower surface of the lowermost iron core block, a part of the rivet protrusions existing on the lower surface of the lowermost iron core block is riveted and embedded in the rivet holes of the lowermost peeling iron core sheet, and the remaining rivet protrusions of the plurality of rivet protrusions are inserted into the non-rivet holes of the lowermost peeling iron core sheet without being riveted, In the core block stacking step, the non-lowermost core block from which the peeling core pieces have been peeled is stacked on the upper side of the lowermost core block having the lowermost peeling core pieces stacked thereon.

4. The method for manufacturing a motor core according to any one of claims 1 to 3, wherein: In the core block manufacturing process, a through hole is formed on each of the core blocks to penetrate the plurality of core sheets along the stacking direction thereof, and a portion of the upper surface of the peeling core sheet stacked on the lower surface of the non-lowermost core block is made to face the through hole. In the core block stacking step, the insert inserted into the through hole is caused to hit the part of the upper surface of the peeling core sheet, thereby peeling the peeling core sheet from the non-lowermost core block.

5. The method for manufacturing a motor core according to any one of claims 1 to 3, wherein: In the iron core block manufacturing process, the multiple riveted recesses and the multiple riveted protrusions are arranged along the circumferential direction of each iron core piece and formed on each iron core piece, and the two riveted holes and the multiple non-riveted holes are arranged along the circumferential direction of the peeling iron core piece and formed on the peeling iron core piece.

6. The method for manufacturing a motor core according to claim 5, wherein: The two caulking holes are formed on the peeling core sheet at positions that are point-symmetrical to each other with respect to the center of the peeling core sheet when viewed in the thickness direction of the peeling core sheet.

7. The method for manufacturing a motor core according to any one of claims 1 to 3, wherein: In the core block manufacturing process, the number of the riveted protrusions formed on the core sheet constituting the lower surface of the core block is set to be greater than the number of the riveted recesses formed on the core sheet constituting the upper surface of the core block, and avoidance holes are formed on the upper surface of the core block, wherein the set excess number of riveted protrusions can be inserted into the avoidance holes without being riveted. In the core block stacking step, the caulking protrusions caulked and fitted in the caulking holes of the peeled peeling core pieces are inserted into the escape holes.

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