Manufacturing method and device for cores

Abstract

To provide a manufacturing method for cores capable of suppressing poor bonding between blocks.SOLUTION: A plurality of blocks 9, each formed by stacking a plurality of plate materials 10, are stacked in a stacking direction of the plate material 10, the plurality of blocks 9 are pressed in the stacking direction, and adjacent blocks 9 in the stacking direction during the pressurization are constrained in a circumferential direction within a first constraining range Ra1 that includes a boundary B and is less than a stack thickness, and are not constrained in the circumferential direction outside the first constraining range Ra1, thereby joining the adjacent blocks 9 through the pressurization.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for manufacturing a core for use in a rotating electrical machine such as an electric motor. [Background technology]

[0002] Patent Document 1 describes a method and apparatus for manufacturing an electromagnetic steel sheet laminate as a conventional core manufacturing method and apparatus.

[0003] In this manufacturing method and apparatus, a plurality of blocks each formed by stacking a plurality of plate materials are stacked, and the stacked blocks are integrated by welding or the like, thereby manufacturing a core for a rotating electrical machine.

[0004] When stacking multiple blocks, the blocks are fitted onto the guide core, and the tongues of each core plate constituting the block are fitted into the grooves of the guide core. This restrains the multiple blocks in the circumferential and radial directions. In this state, the multiple blocks are joined by welding or other methods, enabling the production of highly accurate cores.

[0005] However, each block may be twisted, tilted, or otherwise deformed due to manufacturing errors in the core plates or stacking errors in the core plates. When stacking such blocks, the tongues fit into the grooves in the guide cores to correct the twist or tilt, resulting in a restoring force building up within the blocks. This accumulated force could cause poor joining of the blocks during or after joining. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7091970 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved is the possibility of poor bonding between blocks. [Means for solving the problem]

[0008] The present invention provides a method for manufacturing a core, which includes stacking a plurality of blocks, each formed by stacking a plurality of plate materials, in the stacking direction of the plate materials, pressurizing the plurality of blocks in the stacking direction, and during the pressurization, constraining the blocks adjacent in the stacking direction in the circumferential direction within a first constraining range that includes the boundary between the adjacent blocks and is less than the stacking thickness of the adjacent blocks, and not constraining the blocks in the circumferential direction outside the first constraining range, thereby joining the adjacent blocks through the pressurization.

[0009] The present invention also provides a core manufacturing device that forms a core by stacking a plurality of blocks, each formed by stacking a plurality of plate materials, in the stacking direction of the plate materials, the core manufacturing device comprising: a pressure table for stacking and pressurizing the plurality of blocks in the stacking direction of the plate materials; and convex portions and concave portions that are located within a first constraint range that includes the boundary between adjacent blocks in the stacking direction and is less than the stacking thickness of the adjacent blocks when pressed, thereby constraining the adjacent blocks in the circumferential direction within the first constraint range and not constraining them in the circumferential direction outside the first constraint range. [Effects of the Invention]

[0010] The present invention can suppress poor bonding between blocks when a plurality of blocks are stacked and bonded together. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic front view showing a core manufacturing apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic front view showing the rotor core according to the first embodiment. [Figure 3] FIG. 3 is a schematic perspective view of a block used in the rotor core of FIG. [Figure 4]FIG. 4 is a front view showing the shaft of the manufacturing apparatus of FIG. [Figure 5] FIG. 5 is an enlarged view of a portion of the shaft of FIG. [Figure 6] FIG. 6 is a perspective view showing the fitting of the shaft and the block in FIG. [Figure 7] FIG. 7 is an enlarged plan view showing the fitting portion between the shaft and the block in FIG. [Figure 8] FIG. 8 is a front view showing forces acting on a block according to a comparative example. [Figure 9] FIG. 9 is a front view showing a shaft of a core manufacturing apparatus according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The objective of suppressing poor bonding between blocks was achieved by constraining adjacent blocks in the stacking direction in the circumferential direction within a range that includes the boundary between adjacent blocks in the stacking direction and is less than the stacking thickness of the adjacent blocks.

[0013] The core manufacturing method involves stacking a plurality of blocks 9, each formed by stacking a plurality of plate materials 10, in the stacking direction of the plate materials 10, and then pressurizing the plurality of blocks 9 in the stacking direction. During this pressurization, adjacent blocks 9 in the stacking direction are constrained in the circumferential direction within a first constraining range Ra1 that includes a boundary B between the adjacent blocks 9 and is smaller than the stacking thickness of the adjacent blocks 9, and are not constrained in the circumferential direction outside the first constraining range Ra1. Then, the adjacent blocks 9 are joined by applying pressure.

[0014] When pressurizing, adjacent blocks 9 may be radially constrained within a second constraining range Ra2, Rg that includes the boundary B between adjacent blocks 9 and is less than the stacking thickness of the adjacent blocks 9, and may be radially unconstrained outside the second constraining range Ra2, Rg.

[0015] One of the convex portions 15 and 17 or the concave portions 25 and 27 on the fixed side 7 along the stacking direction may be positioned between adjacent blocks 9 in the stacking direction, and the other of the convex portions 15 and 17 or the concave portions 25 and 27 provided on the adjacent blocks 9 may be fitted into one of the convex portions 15 and 17 or the concave portions 25 and 27 within the first restraint range Ra1 to restrain the adjacent blocks 9 in the circumferential direction.

[0016] Each block 9 may be cylindrical with a hole 23 aligned in the stacking direction, and the fixed side may be the shaft 7 that passes through the hole 23. In this case, one of the convex portions 15 and 17 or the concave portions 25 and 27 may be provided over the entire area of ​​the shaft 7 in the stacking direction, and the other of the convex portions 15 and 17 or the concave portions 25 and 27 may be provided over the entire area of ​​each block 9 in the stacking direction. However, the convex portions 15 and 17 and the concave portions 25 and 27 fit together in the circumferential direction within a first constraint range Ra1 to constrain the block 9 in the circumferential direction, and define play outside the first constraint range Ra1 where they do not fit together in the circumferential direction.

[0017] The hole 23 and the shaft 7 radially restrain the block 9 within the second restraint range Ra2, with the inner circumference of the hole 23 fitting into the outer circumference of the shaft 7, and outside the second restraint range Ra2, Rg, there is clearance where the inner circumference of the hole 23 does not fit into the outer circumference of the shaft 7.

[0018] The blocks 9 can be joined together by any suitable method, but may also be joined together by caulking using pressure.

[0019] The core manufacturing apparatus 1 forms a core 11 by stacking a plurality of blocks 9, each formed by stacking a plurality of plate materials 10, in the stacking direction of the plate materials 10. This manufacturing apparatus 1 may be provided with convex portions 15 and 17 or concave portions 25 and 27 together with a pressurizing table 3. The pressurizing table 3 is a table for stacking and pressing a plurality of blocks 9 in the stacking direction of the plate materials 10.

[0020] The manufacturing apparatus 1 includes a shaft 7 that passes through a hole 23 in a block 9, and one of the convex portions 15 and 17 and the concave portions 25 and 27 may be provided on the shaft 7, while the other of the convex portions 15 and 17 and the concave portions 25 and 27 may be provided on each block 9.

[0021] The recesses 25 and 27 may have a circumferential width that varies in the stacking direction, with the circumferential width being narrowest within the first constraint range Ra1.

[0022] The shaft 7 may have an outer diameter that varies in the stacking direction and is largest within the second constraint ranges Ra2 and Rg. [Example]

[0023] [Manufacturing equipment] Fig. 1 is a schematic front view showing a core manufacturing apparatus according to Example 1. Fig. 2 is a schematic front view showing a rotor core according to Example 1. Fig. 3 is a schematic perspective view of a block used in the rotor core of Fig. 2. In the following description, "upper" and "lower" refer to the upper and lower in the stacking direction of the blocks.

[0024] As shown in Fig. 1, the core manufacturing apparatus 1 includes a movable table 3, a fixed table 5, and a shaft 7. As shown in Fig. 2, the core manufacturing apparatus 1 sequentially stacks (piles up) and bonds a plurality of blocks 9 on the movable table 3 to manufacture a rotor core 11 as the core of this embodiment. The stacking direction of the blocks 9 is the same as the stacking direction of the plate materials 10 described below.

[0025] The movable table 3 is supported by legs 21 relative to the fixed table 5 so that it can move up and down. The movable table 3 can be moved up and down by an appropriate actuator (not shown). The movable table 3 is configured in a plate shape, and is configured so that a block 9 can be placed on its surface. The movable table 3 is a pressure table for applying pressure to the stacked multiple blocks 9 in this embodiment, and supports the placed block 9 from below.

[0026] When a new block 9 is stacked, the movable base 3 moves down by the stacking height of a single block 9. The stacking height refers to the height of the plate materials 10 in the stacking direction.

[0027] The rotor core 11 may have magnet insertion holes into which magnets are inserted, but these are not shown or described for ease of understanding. The core manufacturing apparatus 1 can also form a stator core as the core.

[0028] Each block 9 is formed by laminating a plurality of plate materials 10 formed by punching electromagnetic steel sheets, as shown in Fig. 3. In this block 9, the plate materials 10 are joined together by caulking.

[0029] Although the crimping is not particularly limited, as an example, it is performed through a plurality of crimping portions 13 that are concave and convex on the front and back surfaces of each plate material 10. The plurality of crimping portions 13 are arranged at intervals in the circumferential direction of each plate material 10. In plate materials 10 adjacent in the stacking direction, the convex crimping portion 13 on the bottom surface (bottom surface) of the upper plate material 10 fits into the concave crimping portion 13 on the top surface (top surface) of the lower plate material 10. Note that the plate materials 10 can also be joined by other methods such as welding or adhesive.

[0030] The block 9 has a cylindrical shape with a hole 23 aligned in the stacking direction. Keys 15 and 17 as convex portions protrude radially inward from the hole 23 and are arranged facing each other in the radial direction of the hole 23. These keys 15 and 17 are provided on each plate 10 and form convex stripes that extend over the entire area of ​​the block 9 in the stacking direction. The keys 15 and 17 have a constant circumferential width, but the circumferential width may vary.

[0031] The keys 15 and 17 may be configured to be located only in a portion of the block 9 in the stacking direction. For example, the keys 15 and 17 may be provided only in a portion that is located in a first range Ra1, which is a first restraint range when pressure is applied, as described below. Also, three or more keys may be provided in the circumferential direction, or only one key may be provided.

[0032] The concave crimping portion 13 of the upper plate material 10 is located on the upper surface of the block 9, and the convex crimping portion 13 of the lower plate material 10 is located on the lower surface of the block 9. Adjacent stacked blocks 9 are joined by these crimping portions 13. Therefore, the blocks 9 are joined to each other by the crimping portions 13 under pressure.

[0033] In addition, the crimped portion 13 on the bottom surface of the lowest block 9 of the rotor core 11 in Fig. 2 is formed as a through hole or the like and is not convex. The blocks 9 can also be joined by welding or adhesive.

[0034] Fig. 4 is a front view showing the shaft 7 of the manufacturing apparatus 1 of Fig. 1. Fig. 5 is an enlarged view of a portion of the shaft of Fig. 4. Fig. 6 is a perspective view showing the fitting of the shaft 7 and block 9 of Fig. 4. Fig. 7 is an enlarged plan view showing the fitting of the shaft 7 and block 9 of Fig. 6.

[0035] 1 and 4 to 7, the shaft 7 is formed in a columnar shape, in this embodiment a cylindrical shape, that passes through the hole 23 of the block 9. The shaft 7 guides the block 9 that is joined as the fixed side. The lower end surface of the shaft 7 is fixed to the fixed base 5, and the shaft 7 protrudes from the fixed base 5 in the stacking direction. The shaft 7 also passes through the movable base 3. Note that instead of the shaft 7, it is also possible to provide a hole into which the block 9 is inserted to guide the block 9.

[0036] The shaft 7 includes a circumferential restraint portion 29 and a radial restraint portion 33. In this embodiment, the circumferential restraint portion 29 is provided in one of the key groove portions 25, and the radial restraint portion 33 is provided on the outer periphery of the shaft 7. Note that the circumferential restraint portion 29 may be provided in both the key groove portions 25 and 27.

[0037] It is also possible to provide the key portions 15 and 17 on the shaft 7 and the key grooves 25 and 27 on the block 9. When providing a hole into which the block 9 is inserted instead of the shaft 7, it is only necessary to provide either the key grooves 25 and 27 or the key portions 15 and 17 on the inner periphery of the hole, and the other of the key grooves 25 and 27 or the key portions 15 and 17 on the outer periphery of the block 9.

[0038] The key grooves 25 and 27 are provided along the lamination direction, which is the axial direction of the shaft 7. The key grooves 25 and 27 extend over the entire shaft 7 within the range in which the rotor core 11 is inserted. The key grooves 25 and 27 are disposed at positions corresponding to the key portions 15 and 17, and in this embodiment, are located on both sides in the radial direction.

[0039] These key grooves 25 and 27 slidably engage with the key portions 15 and 17 in the stacking direction of the blocks 9 to guide the stacking of the blocks 9. One of the key grooves 25 fits into the key portion 15 within a first range Ra1, which will be described later, to constrain the blocks 9 in the circumferential direction. Note that the circumferential constraint of the blocks 9 may be achieved not between the shaft 7 and the blocks 9, but between another member and the blocks 9. For example, multiple pillars protruding from the fixed base 5 in the same manner as the shaft 7 may be provided, and these pillars may be inserted into holes in the blocks 9, such as magnet insertion holes, to constrain the blocks 9. In this case, the pillars fit into the holes in the blocks 9 in the circumferential direction within the first range Ra1.

[0040] 4, 5, and 7, the keyway portion 25 has a circumferentially constrained portion 29 and a circumferentially unconstrained portion 31. In FIG. 7, the circumferentially unconstrained portion 31 of the keyway 25 refers to the circumferentially unconstrained portion 31 of the keyway 27. In this embodiment, the keyway 27 has only the circumferentially unconstrained portion 31.

[0041] Each peripheral restraint portion 29 of the key groove portion 25 is located between the blocks 9 within a first range Ra1, which is a first restraint range that includes the boundary B (see Figure 1) between the adjacent blocks 9 to be joined and is smaller than the stacking thickness of the adjacent blocks 9.

[0042] The stacking thickness of adjacent blocks 9 is the total stacking thickness of the adjacent blocks 9, and the first range Ra1 includes the boundary B between the blocks 9. The dimension in the stacking direction can be set appropriately as long as it is within a range below this stacking thickness. In this embodiment, a circumferential restraint portion 29 is formed in the key groove portion 25 in the first axial range Ra1.

[0043] It is also possible to provide a plurality of first ranges Ra1.

[0044] In this embodiment, one first area Ra1 is provided at a position where adjacent blocks 9 are joined. That is, each time adjacent blocks 9 are joined, the joined block 9 is lowered by the stacking height of a single block 9, and the next block 9 is stacked on top of it and joined. That is, in this embodiment, adjacent blocks 9 are always joined in one first area Ra1. Note that the boundary B between the blocks 9 is located in the center of the first area Ra1 in the stacking direction, but the position of the boundary B relative to the first area Ra1 can be set as appropriate.

[0045] The circumferential restraint portion 29 is configured by restraint surfaces 29a located in a first range Ra1. The restraint surfaces 29a are flat surfaces aligned along the stacking direction and face each other in the circumferential direction of the shaft 7. Like the key grooves 25 in Fig. 7, the restraint surfaces 29a of each circumferential restraint portion 29 circumferentially restrain adjacent blocks 9 to be joined by the key portions 15 fitting therebetween, for example, by light press-fitting.

[0046] Outside the first range Ra1 in the stacking direction, a circumferential unconstrained portion 31 is formed in the keyway 25. The shaft 7 of this embodiment has second to sixth ranges Rb to Rf in which the circumferential unconstrained portion 31 is formed in the keyway 25 as ranges outside the first range Ra1. The entire keyway 27 becomes the circumferential unconstrained portion 31. The first to fifth ranges Ra to Re of the keyway 27 other than the sixth range Rf have flat unconstrained surfaces in the stacking direction.

[0047] The circumferential unconstrained portion 31 allows the key portions 15 and 17 and the key groove portions 25 and 27 to be unfitted, and allows the adjacent block 9 to be unconstrained in the circumferential direction. Specifically, the circumferential unconstrained portion 31 defines a play or gap between the key grooves 25 and 27 and the key portions 15 and 17 to be unfitted in the circumferential direction, as in the lower key groove 27 in Figure 7.

[0048] In the second and third ranges Rb and Rc adjacent to the first range Ra1, the circumferential unconstrained portion 31 of the keyway 25 is composed of unconstrained surfaces 31b and 31c with gradients α and β, respectively. Due to the gradients α and β, the unconstrained surfaces 31b and 31c are inclined with respect to the stacking direction so that the circumferential width of the circumferential unconstrained portion 31 increases with increasing distance from the circumferential constrained portion 29. In other words, the circumferential width of the keyway portion 25 varies in the stacking direction, and the circumferential width is narrowest within the first range Ra1.

[0049] The non-constraint surfaces 31b and 31c themselves are flat surfaces. However, the non-constraint surfaces 31b and 31c may be curved surfaces. The slopes α and β of the non-constraint surfaces 31b and 31c are set to the same value, but may be different.

[0050] A fourth area Rd is set adjacent to the third area Rc on the opposite side (below) of the first area Ra1 in the stacking direction. In the fourth area Rd, the circumferential non-constraint portion 31 of the keyway 25 is configured with a non-constraint surface 31d that is the same surface as the first area Ra1.

[0051] That is, the non-constraint surfaces 31d in the fourth range Rd are flat surfaces along the stacking direction and face each other in the circumferential direction of the shaft 7. However, the non-constraint surfaces 31d of the key grooves 25 in the fourth range Rd are spaced apart in the circumferential direction by a larger distance than the constraint surfaces 29a in the first range Ra1.

[0052] A fifth range Re is set adjacent to the second range Rb on the opposite side (upper side) of the first range Ra1 in the stacking direction. In the fifth range Re, the circumferential unconstrained portion 31 of the keyway 25 is configured with a curved unconstrained surface 31e whose circumferential width gradually increases with increasing distance from the unconstrained surface 31b.

[0053] A sixth area Rf is set adjacent to the fifth area Re on the opposite side (upper side) of the first area Ra1 in the stacking direction. The sixth area Rf is a region that forms the tip end of the shaft 7.

[0054] In this sixth range Rf, the circumferential non-constraint portions 31 of the keyways 25 and 27 guide the insertion of the keys 15 and 17. The sixth range Rf is formed by a non-constraint surface 31f in which the circumferential width of the circumferential non-constraint portion 31 gradually increases with increasing distance from the non-constraint surface 31e. The non-constraint surface 31f is formed by a flat surface, but may also be formed by a curved surface.

[0055] The outer periphery of the shaft 7 has a radial restraint portion 33 in a first range Ra2, which serves as a second restraint range in this embodiment. Note that in this embodiment, the first range Ra2, which serves as the second restraint range, is the same axial range as the first range Ra1, which serves as the first restraint range, and is therefore distinguished from the first range Ra1, which serves as the first restraint range, by using a different symbol. These first ranges Ra1 and Ra2 may also be collectively referred to as the first range Ra.

[0056] The radial restraint portion 33 may be provided within a second restraint range that includes the boundary B between the blocks 9 and is smaller than the stacking thickness of adjacent blocks 9. In this embodiment, the second restraint range is a first range Ra2 that is the same as the first range Ra1 as the first restraint range, but it does not have to be the same as the first restraint range and may be larger or smaller than the first restraint range. Therefore, the second restraint range can be a range that includes the boundary B and is smaller than the stacking thickness of adjacent blocks 9, separate from the first range Ra1 as the first restraint range.

[0057] The radial restraint portion 33 of this embodiment fits into the inner periphery of the hole 23 of the adjacent block 9 to be joined, thereby restraining the adjacent block 9 in the radial direction. The radial restraint portion 33 is configured with a restraint surface 33a, which is an outer circumferential surface that is flat in the stacking direction and formed around the shaft 7. The hole 23 of the block 9 is fitted into the restraint surface 33a of the radial restraint portion 33, for example, by light press fitting.

[0058] The radial constraint of the block 9 may be performed not between the shaft 7 and the block 9, but between another member and the block 9. For example, if a hole into which the block 9 is inserted is provided instead of the shaft 7, the inner periphery of the hole may be fitted with the outer periphery of the block 9 within the first range Ra2. Furthermore, if multiple pillars protruding from the fixed base 5 similar to the shaft 7 are provided, the block 9 may be constrained by inserting each of these pillars into holes in the block 9, such as magnet insertion holes. In this case, the pillars fit radially into the holes in the block 9 within the first range Ra2.

[0059] Outside the first range Ra in the stacking direction, a diameter non-constraint portion 35 is formed on the outer periphery of the shaft 7. The diameter non-constraint portion 35 defines a play where the inner periphery of the hole 23 of the block 9 does not fit onto the outer periphery of the shaft 7 outside the first range Ra.

[0060] In the second and fifth ranges Rb and Re and the third range Rc, the diameter non-constraint portion 35 is inclined at angles θ1 and θ2, respectively, and is configured with non-constraint surfaces 35b and 35c formed as tapered surfaces that gradually reduce the diameter of the shaft 7 as they move away from the first range Ra. In other words, the outer diameter of the shaft 7 varies in the stacking direction, and is largest within the first range Ra. The angles θ1 and θ2 of the non-constraint surfaces 35b and 35c are set to the same value, but may be different.

[0061] In the fourth range Rd, the radially unconstrained portion 35 is made up of a non-constraint surface 35d that is configured flat in the stacking direction on the radially constrained portion 33 similar to the first range Ra. However, the non-constraint surface 35d has a smaller diameter than the constrained surface 33a of the radially constrained portion 33.

[0062] In the sixth range Rf, the diameter unconstrained portion 35 is configured with a tapered unconstrained surface 35f. The unconstrained surface 35f is continuous with the unconstrained surface 35b and has a larger angle than the unconstrained surface 35b.

[0063] [Core manufacturing method] In the core manufacturing method of this embodiment, a plurality of blocks 9 are sequentially stacked and joined as shown in FIG. 1 to manufacture a rotor core 11 consisting of four stages of blocks as shown in FIG.

[0064] When stacking the blocks 9, they are rotated by a predetermined angle around the axis so that adjacent blocks 9 are in different phases. By stacking the blocks 9 while making the phases different in this way, tilting and deformation after stacking due to uneven thickness is suppressed. Note that the blocks 9 may also be stacked without being rotated around the axis.

[0065] When stacking the blocks 9, the shafts 7 are inserted through the holes 23. As a result, the blocks 9 are stacked in order on the table 3 while being guided in the stacking direction.

[0066] At this time, in each block 9, the keys 15 and 17 are inserted into the key grooves 25 and 27 from the upper ends thereof, respectively, while the inner periphery of the hole 23 moves down along the outer periphery of the shaft 7.

[0067] As a result of these descents, the block 9 descends sequentially through the sixth, fifth, and second ranges Rf, Re, and Rb, and its posture is sequentially corrected by the circumferential unconstrained portion 31 and the radial unconstrained portion 35.

[0068] In the case of the first tier, the blocks 9 are stacked on the movable base 3, with their upper surfaces positioned within the first range Ra. Specifically, the inner periphery of the hole 23 of the block 9 of the first tier passes through the radial constraint portion 33 on the outer periphery of the shaft 7, with a portion of the upper side remaining engaged with the radial constraint portion 33. Meanwhile, the inner periphery of the hole 23 passes through the circumferential constraint portion 29 of the key portion 15 and key groove 25 of the block 9 of the first tier, with a portion of the upper side remaining engaged with the circumferential constraint portion 29.

[0069] As a result, a portion of the upper side of the first-stage block 9 is constrained in the circumferential and radial directions within the first range Ra. The lower side of the first-stage block 9, excluding the portion of the upper side, is located in the third range Rc, i.e., it is not constrained in the circumferential and radial directions outside the first range Ra.

[0070] The second-tier blocks 9 are stacked on the first-tier blocks 9, with their lower surfaces positioned within the first range Ra. Specifically, a portion of the lower side of the second-tier blocks 9 is constrained in the circumferential and radial directions within the first range Ra. As described above, this circumferential and radial constraints need only be performed within the first and second constraint ranges, respectively, and do not have to be performed within the same range in the stacking direction. Note that the upper portion of the second-tier blocks 9, excluding the portion of the lower side, is positioned within the second range Rb, i.e., it is unconstrained in the circumferential and radial directions outside the first range Ra.

[0071] By stacking the blocks 9 in this way, the key portions 15 and key groove portions 25 that fit together are positioned between the adjacent blocks 9 in the first and second rows.

[0072] In this state, the upper surface of the second-stage block 9 is pressed against the stationary movable table 3. As a result, the adjacent blocks 9 in the first and second stages are pressed in the stacking direction. This pressing can be performed by a well-known pressing member (not shown).

[0073] As a result of this pressure, the crimped portion 13 of the second-tier block 9 fits into the crimped portion 13 of the first-tier block 9 at boundary B, joining the adjacent first-tier and second-tier blocks 9. In this way, adjacent blocks 9 are joined through pressure. Note that even when joining blocks 9 by welding or adhesive, pressure is applied to adjacent blocks 9 at that time, so joining is achieved through pressure.

[0074] During this pressurization, the circumferential restraint portion 29 and the radial restraint portion 33 in the first range Ra of the shaft 7 restrain only a portion of the stacking direction of both adjacent blocks 9 in the circumferential and radial directions, so that twisting and tilting are corrected only in a portion of both adjacent blocks 9.

[0075] As a result, the force accumulated in the adjacent blocks 9 can be reduced, and bonding failure between the blocks 9 is suppressed.

[0076] When stacking the third block 9 on the second block 9, the movable base 3 moves down relative to the fixed base 5 and the shaft 21 by the thickness of the stacked blocks 9.

[0077] As a result of this lowering of the movable base 3, the first range Ra is positioned between the second and third tier blocks 9. Therefore, the second and third tier blocks 9 are coupled in the same manner as the first and second tier blocks 9.

[0078] The fourth-stage block 9 is also stacked on the third-stage block 9 after the movable base 3 is lowered, and is connected in the same manner as the first-stage and second-stage blocks 9 described above.

[0079] In this way, as shown in Figure 2, the blocks 9 from the first to fourth rows are sequentially joined within the first range Ra between adjacent blocks 9, thereby obtaining a rotor core 11 in which poor joining between the blocks 9 is suppressed.

[0080] Fig. 8 is a front view showing forces acting on a block according to a comparative example. For ease of explanation, in Fig. 8, components corresponding to those in Example 1 are denoted by the same reference numerals.

[0081] In the comparative example of FIG. 8, the outer periphery of the shaft 7 is a straight cylindrical shape, and the key grooves 25 and 27 are also straight grooves that do not vary in width in the circumferential direction along the lamination direction of the shaft 7.

[0082] In this comparative example, when stacking the blocks 9, the holes 23 are fitted onto the shafts 7 to constrain them radially throughout the entire stacking direction of the blocks 9, and the key portions 15 and 17 are fitted into the key groove portions 25 and 27 to constrain them circumferentially.

[0083] In this case, even if each plate material 10 that makes up the block 9 is manufactured with an error within the tolerance, the tolerance accumulates throughout the block 9, and the block 9 may tilt or twist relative to the shaft 7 as shown in Figure 8.

[0084] When a load P is applied to the block 9 for connection in this state of FIG. 8, the position of the block 9 is corrected in the horizontal direction, and a rotation moment M with respect to the shaft 7 is generated.

[0085] This rotational moment M causes the keys 15 and 17 to come into contact with the key grooves 25 and 27 on the upper and lower sides of the block 9, generating a reaction force F. As a result, a force that restores the block 9 to its tilted or twisted state accumulates. This accumulation of force may result in insufficient bonding at the boundary B between the blocks 9 (see Figure 1).

[0086] In contrast, in this embodiment, when adjacent blocks 9 are joined, only in the first range Ra, a portion of each adjacent block 9 is constrained in the circumferential and radial directions, and the block 9 is not constrained in the remaining portion.

[0087] Therefore, even if the entire block 9 is tilted or twisted, the adjacent blocks 9 can be securely joined together.

[0088] In this way, deformation of the blocks 9 can be tolerated to the extent that it does not affect the final product shape of the rotor core 11, and poor bonding between the blocks 9 can be suppressed, improving yield and, as a result, improving the bonding strength between the blocks 9.

[0089] This can prevent the blocks 9 and rotor core 11 from galling the shaft 7, reducing wear and damage to the shaft 7. This reduces the maintenance frequency of the manufacturing apparatus 1, reduces downtime, and improves the operating rate.

[0090] It is also possible to prevent product deformation, dents, scratches, etc. due to interference between the shaft 7 and the block 9. [Example]

[0091] 9 is a front view showing a shaft of a core manufacturing apparatus according to Example 2 of the present invention. Since Example 2 has a basic configuration in common with Example 1, the same reference numerals are used for corresponding components and redundant explanations will be omitted.

[0092] In Example 2, the first range Ra is extended in the stacking direction compared to Example 1. In the first range Ra, only the end regions located on the opposite side of adjacent blocks 9 in the stacking direction are located in the second range Rb and the third range Rc. The fifth range Re in Example 1 is the second range Rb in this example. The rest is the same as Example 1.

[0093] The circumferential restraint portion 29a is provided only within the first range Ra1 as the first restraint range, and the radial restraint portion 33 is provided in the seventh range Rg as the second restraint range extending from the first range Ra2 to the second range Rb.

[0094] In the second embodiment, the same effects as those of the first embodiment can be achieved. [Explanation of symbols]

[0095] 1 Manufacturing equipment 3 Movable table (pressure table) 7 shaft 9 blocks 10 Board material 11 Rotor core (core) 13 Crimping part 15, 17 Key part (convex part) 23 holes 25, 27 Key groove (recess) Ra1 First range (first constraint range) Ra2 First range (second constraint range) Rb Second range (outside of first constraint range, outside of second constraint range, second constraint range) Rc Third range (outside the first constraint range, outside the second constraint range) Rg 7th range (2nd constraint range)

Claims

1. stacking a plurality of blocks, each formed by stacking a plurality of plate materials, in a stacking direction of the plate materials; Pressurizing the plurality of blocks in the stacking direction; When the pressure is applied, the blocks adjacent to each other in the stacking direction are constrained in the circumferential direction within a first constraining range that includes a boundary between the adjacent blocks and is smaller than the stacking thickness of the adjacent blocks, and are not constrained in the circumferential direction outside the first constraining range, The adjacent blocks are bonded together by applying pressure. Core manufacturing method.

2. A method for manufacturing the core of claim 1, comprising: When the pressure is applied, the adjacent blocks are constrained in the radial direction within a second constraining range that includes a boundary between the adjacent blocks and is smaller than a stacking thickness of the adjacent blocks, and the adjacent blocks are not constrained in the radial direction outside the second constraining range. Core manufacturing method.

3. A method for manufacturing the core of claim 1 or 2, one of a convex portion and a concave portion on a fixed side along the stacking direction is positioned between the blocks adjacent to each other in the stacking direction, the other of the convex portion or the concave portion provided on the adjacent block is fitted into one of the convex portion or the concave portion within the first constraint range to constrain the adjacent block in the circumferential direction. Core manufacturing method.

4. A method for manufacturing the core of claim 3, comprising the steps of: Each block has a cylindrical shape having a hole aligned along the stacking direction, the fixed side is a shaft that passes through the hole, one of the convex portion and the concave portion is provided over the entire area of ​​the shaft in the stacking direction, and the other of the convex portion and the concave portion is provided over the entire area of ​​each block in the stacking direction, The protrusion and the recess are fitted together in the circumferential direction within the first constraint range to constrain them in the circumferential direction, and define a play outside the first constraint range where they are not fitted together in the circumferential direction. Core manufacturing method.

5. A method for manufacturing the core of claim 3, comprising the steps of: The hole and the shaft define a play where the inner periphery of the hole is fitted onto the outer periphery of the shaft within the second constraint range to constrain the hole in the radial direction, and the inner periphery of the hole is not fitted onto the outer periphery of the shaft outside the second constraint range. Core manufacturing method.

6. 3. The method for laminating a core according to claim 1 or 2, The blocks are joined by caulking using the pressure. Core lamination method.

7. A core manufacturing apparatus for forming a core by stacking a plurality of blocks, each formed by stacking a plurality of plate materials, in a stacking direction of the plate materials, comprising: a pressurizing table for stacking and pressing the plurality of blocks in the stacking direction of the plate material; a convex portion and a concave portion that are located within a first constraining range that includes a boundary between the adjacent blocks adjacent in the stacking direction and is smaller than the stacking thickness of the adjacent blocks when the pressure is applied, and that constrain the blocks in the circumferential direction within the first constraining range, and that do not constrain the blocks in the circumferential direction outside the first constraining range; A core manufacturing device equipped with:

8. The core manufacturing apparatus of claim 7, Each block has a cylindrical shape with a hole aligned along the stacking direction, a shaft that passes through a hole in the block; one of the convex portion and the concave portion is provided over the entire area of ​​the shaft in the stacking direction, and the other of the convex portion and the concave portion is provided over the entire area of ​​each block in the stacking direction, The protrusion and the recess are fitted together in the circumferential direction within the first constraint range to constrain them in the circumferential direction, and define a play outside the first constraint range where they are not fitted together in the circumferential direction. Core manufacturing equipment.

9. The core lamination device of claim 8, the recess has a circumferential width that varies in the stacking direction and is narrowest within the first constraint range; Core stacking device.

10. The core manufacturing apparatus according to claim 8 or 9, The hole and the shaft define a play where the inner periphery of the hole is fitted onto the outer periphery of the shaft within the second constraint range to constrain the hole in the radial direction, and the inner periphery of the hole is not fitted onto the outer periphery of the shaft outside the second constraint range. Core manufacturing equipment.

11. 10. A core manufacturing apparatus according to claim 10, the shaft has an outer diameter that varies in the stacking direction and is largest within the second constraint range; Core manufacturing equipment.

Images