Cylindrical core and manufacturing method thereof

Abstract

To provide a cylindrical core with a high yield in terms of material efficiency. [Solution] The cylindrical core 1 includes a plurality of partially cylindrical partial cores 2 connected in the circumferential direction C. Each partial core 2 includes a plurality of unit cores 4, each having one or more laminated metal plates 3 with the same outer circumferential shape, stacked in the axial direction A with the orientation of each unit core 4 changed so that both end edges in the circumferential direction C are interchanged for each unit core 4. Adjacent partial cores 2 have overlapping portions 6 where each unit core 4 of one partial core 2 overlaps with each unit core 4 of the other partial core 2 when viewed in the axial direction A. The partial cores 2 are closely connected to each other via the overlapping portions 6.

Description

[Technical Field]

[0001] The present invention relates to a cylindrical core including a plurality of partially cylindrical partial cores connected in the circumferential direction, and a method for manufacturing the same. [Background technology]

[0002] Conventionally, an annular laminated core has been known, which is configured by arranging split cores, each divided into teeth that constitute a stator, in a circular shape with the teeth facing the central axis. The split core is configured by laminating multiple T-shaped metal plates (core pieces) of approximately the same shape by crimping (see, for example, Patent Document 1).

[0003] According to the split core manufacturing method of Patent Document 1, when forming the split core, a plurality of first core laminations in one row and a plurality of second core laminations in the other row aligned in the width direction of the steel plate, which is perpendicular to the feed direction of the steel plate, are punched out row by row simultaneously. The punched first core laminations and second core laminations are alternately stacked to form the split core. A plurality of these split cores are connected in the circumferential direction to obtain an annular laminated core.

[0004] Here, the first and second core laminations each have a T-shape with a back yoke portion extending circumferentially on the radially outer side and teeth protruding radially inward from the center of the back yoke portion. One edge of the circumferentially extending back yoke portion of the first core lamination has a concave shape recessed in the circumferential direction, and the other edge has a convex shape protruding in the circumferential direction. To match this, one edge of the second core lamination has a convex shape and the other edge has a concave shape.

[0005] Further, a technique for manufacturing a cylindrical core by laminating ring-shaped metal plates punched from a steel plate by caulking lamination or adhesive lamination has also been known. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-236597 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the split core manufacturing method in Patent Document 1 is a technology for manufacturing T-shaped split cores that are connected in multiple circumferential directions to obtain a laminated core, but this technology is not suitable for manufacturing cylindrical cores without teeth.

[0008] Furthermore, according to the conventional technique of manufacturing a cylindrical core by stacking ring-shaped metal plates punched from a steel plate, a large portion of the steel plate is wasted during the manufacturing of the cylindrical core, resulting in a low yield in terms of material efficiency.

[0009] In view of the above problems of the prior art, an object of the present invention is to provide a cylindrical core with a high yield in terms of material efficiency and a method for manufacturing the same. [Means for solving the problem]

[0010] The cylindrical core of the present invention comprises a plurality of partially cylindrical partial cores connected in the circumferential direction thereof, each of which comprises a unit core having one or more laminated metal plates having the same outer circumferential shape, stacked in the axial direction of the cylindrical core while changing the position of each unit core so that both circumferential edges of each unit core are interchanged.

[0011] The adjacent partial cores have overlapping portions where the unit cores of one partial core overlap with the unit cores of the other partial core when viewed in the axial direction. The partial cores are closely connected to each other via the overlapping portions. The overlapping portion between the adjacent partial cores is The cylindrical core has through holes extending from one surface to the other surface in the axial direction, and pins inserted into the through holes and extending from the one surface to the other surface. The adjacent partial cores are closely connected in the overlapping portion between the two partial cores by alternately applying forces in one direction and the other direction in the circumferential direction to the unit cores of one partial core and the unit cores of the other partial core via the pins forcibly inserted into the through holes. . The manufacturing method of a cylindrical core of the present invention is a method for manufacturing a cylindrical core comprising a plurality of partially cylindrical partial cores connected together in the circumferential direction, each partial core comprising a unit core having one or more laminated metal plates having the same outer peripheral shape, stacked in the axial direction of the cylindrical core with the position changed so that both circumferential end edges of each unit core are interchanged, adjacent partial cores have overlapping portions where each unit core of one partial core overlaps with each unit core of the other partial core when viewed in the axial direction, and the partial cores are closely connected to each other via the overlapping portions, and the overlapping portions between adjacent partial cores comprise a through hole extending from one surface to the other surface of the cylindrical core in the axial direction, and a pin inserted into the through hole and extending from the one surface to the other surface, and the pin has crushed portions formed by pressing the pin in the longitudinal direction of the pin at both end surfaces. In the manufacturing method of the cylindrical core, the crushed portion is formed by using a tool having a tip surface with a diameter larger than that of the pin and a protrusion in the center of the tip surface, and pressing the center of both end faces of the pin along the length of the pin to crush it. [Effects of the Invention]

[0012] The present invention Cylindrical core According to the method, each metal plate constituting the cylindrical core has the same partially circular outer circumferential shape that conforms to the partially cylindrical shape of the partial core. Therefore, each metal plate constituting the cylindrical core can be punched out of the steel plate from which it is made, minimizing the waste of material. Therefore, a cylindrical core can be provided with a high yield in terms of material efficiency. Furthermore, it is possible to provide a cylindrical core in which the partial cores are joined together with high circumferential tightness via pins inserted into the through holes in the overlapping portions of adjacent partial cores. According to the method for manufacturing a cylindrical core of the present invention, the above-mentioned tool is used to crush the center of both end faces of the pin, thereby strengthening the fastening force between the partial cores and making it possible to construct a cylindrical core without placing it in a case. In addition, the flat tip of the protruding tool prevents the pin from protruding, improving the workability of the next process. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a plan view showing a cylindrical core according to a first embodiment of the present invention as viewed along its axial direction. [Figure 2] FIG. 2 is a side view of the cylindrical core of FIG. [Figure 3] 2 is a diagram showing how adjacent partial cores are connected to each other via overlapping portions in the cylindrical core of FIG. 1. FIG. [Figure 4] FIG. 10 is a side view showing a cylindrical core according to a second embodiment of the present invention. [Figure 5] 5 is a diagram showing how adjacent partial cores are connected to each other via overlapping portions in the cylindrical core of FIG. 4. FIG. [Figure 6] FIG. 10 is a plan view of a cylindrical core according to a third embodiment of the present invention. [Figure 7] Figure 7A is a diagram showing how adjacent partial cores in the cylindrical core of Figure 6 are connected via overlapping portions, and Figure 7B is a diagram showing how adjacent partial cores are integrated by inserting a pin. [Figure 8] FIG. 10 is a plan view of a cylindrical core according to a fourth embodiment of the present invention. [Figure 9]9A is a cross-sectional view taken along line IX-IX in FIG. 8, FIG. 9B is a diagram showing a method for forming a crushed portion in this cross-section, FIG. 9C is a diagram showing another method for forming a crushed portion, and FIG. 9D is a diagram showing a method for preventing slight protrusions from occurring at both end faces of the pin in the embodiment of FIG. 6. [Figure 10] FIG. 10 is a plan view of a cylindrical core according to a fifth embodiment of the present invention. [Figure 11] 11 is a perspective view showing the shape of one end portion in the circumferential direction of a partial core of the cylindrical core of FIG. 10. FIG. [Figure 12] FIG. 12A is a plan view of a portion of a cylindrical core according to a sixth embodiment of the present invention, and FIG. 12B is a perspective view showing the shape of one end of the partial core of this cylindrical core. [Figure 13] FIG. 13 is a plan view showing a cylindrical core according to a seventh embodiment of the present invention. [Figure 14] 14A to 14C are diagrams showing how adjacent partial cores in FIG. 13 are connected using through holes and pins to form a cylindrical core. [Figure 15] FIG. 3 is an explanatory view for explaining a partial core manufacturing device used to manufacture the partial cores according to the first and second embodiments. [Figure 16] 16A to 16D are diagrams showing a procedure for forming a cylindrical core by joining partial cores. [Figure 17] 17A to 17C are diagrams showing modified examples in which the partial cores of FIGS. 3, 5, and 7A are provided with chamfered portions extending along the radial direction, and FIG. 17D is a diagram showing a method of forming the chamfered portions. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 shows a cylindrical core 1 according to a first embodiment of the present invention as viewed in an axial direction A (see Fig. 2), which is a direction along the central axis of the cylindrical core. Fig. 2 shows the cylindrical core 1 as viewed from the side.

[0015] 1 and 2, this cylindrical core 1 includes a plurality of partially cylindrical partial cores 2 connected in the circumferential direction C. Each partial core 2 includes a plurality of unit cores 4, each having one metal plate 3 (consisting of one metal plate 3), stacked in the axial direction A while changing the position of each unit core 4 so that both end edges in the circumferential direction C are interchanged. However, in each partial core 2, the positions of unit cores 4 adjacent in the axial direction A are shifted in the circumferential direction C each time both end edges of each unit core 4 are interchanged, as will be described later.

[0016] The unit cores 4 (metal plates 3) are laminated by crimp lamination, which involves laminating them via crimps (dowels) 5. As crimp lamination, round dowel crimping or V dowel crimping is used. Note that instead of crimp lamination, other lamination methods such as adhesive lamination may also be used.

[0017] Each metal plate 3 is an arc-shaped metal plate having the same outer peripheral shape, and both end edges in the circumferential direction C when viewed in the axial direction A form two straight lines that form a predetermined central angle with the central axis of the cylindrical core 1 as the center. This central angle is, for example, the central angle obtained by dividing 360° by a natural number n. In this embodiment, the natural number n is 8. That is, in this embodiment, the cylindrical core 1 is formed by connecting eight partial cores 2.

[0018] Adjacent partial cores 2 have overlapping portions 6 where each unit core 4 of one partial core 2 overlaps with each unit core 4 of the other partial core 2 when viewed in the axial direction A. The partial cores 2 are closely connected to each other via their respective overlapping portions 6.

[0019] That is, in adjacent partial cores 2, in one partial core 2, the position of each unit core 4 in the circumferential direction C is repeatedly displaced by a predetermined amount in one direction and the other direction each time the both end edges are switched as described above. In the other partial core 2, the position of each unit core 4 in the circumferential direction C is repeatedly displaced by the predetermined amount in the direction opposite to that of the one partial core 2 each time the both end edges are switched as described above. The predetermined amount coincides with the central angle θ (see FIG. 1) occupied by the overlapping portion 6 between the adjacent partial cores 2.

[0020] 3 shows how adjacent partial cores 2 are connected to each other as viewed from the central axis of the cylindrical core 1. In each overlapping portion 6 between one adjacent partial core 2 and the other adjacent partial core 2, the unit cores 4 are stacked in the axial direction A while changing their positions so that both end edges in the circumferential direction C are interchanged, as described above.

[0021] Therefore, the overlapping portions 6 of both partial cores 2 have shapes that fit together in the circumferential direction. Therefore, adjacent partial cores 2 are connected by fitting their overlapping portions 6 together. The cylindrical core 1 includes a plurality of partial cores 2 that are connected in this way in the circumferential direction C to form a cylindrical shape, and are housed in a cylindrical case 7, as shown in FIG.

[0022] According to this embodiment, adjacent partial cores 2 are closely connected via overlapping portions 6, and the ends of adjacent metal plates 3 are electrically connected, so it is possible to provide a cylindrical core 1 that is essentially equivalent to a cylindrical core made by laminating annular metal plates. Therefore, when this cylindrical core 1 is applied to a slotless motor, it exhibits a magnetic reflection function that prevents leakage of magnetic flux, and it is possible to prevent the cylindrical core 1 from generating positive and negative magnetic forces and suppress the occurrence of cogging.

[0023] The cylindrical core 1 is formed by stacking arc-shaped metal plates 3 having the same outer peripheral shape. Therefore, compared to when a cylindrical core is formed by stacking annular metal plates, the steel plate from which the metal plates 3 are made can be used efficiently to minimize waste, thereby reducing material costs.

[0024] Fig. 4 shows a cylindrical core 1a according to a second embodiment of the present invention as viewed from the side. The cylindrical core 1a as viewed along the axial direction A is the same as that shown in Fig. 1. In the first embodiment, each partial core 2 includes a plurality of, for example, ten, stacked unit cores 4 each made of a single metal plate 3, whereas in this embodiment, as shown in Fig. 4, each partial core 2a includes a plurality of, for example, three, stacked unit cores 4a each made of several, for example, four, metal plates 3.

[0025] 5 shows how adjacent partial cores 2a are connected to each other. As in the first embodiment, in each partial core 2a, the unit cores 4a are stacked in the axial direction A while changing their positions so that both end edges in the circumferential direction C of each unit core 4a are interchanged. Each partial core 2a has an overlapping portion 6a where one unit core 4a and the other unit core 4a overlap as seen in the axial direction A.

[0026] Therefore, both partial cores 2a have shapes that allow them to fit together at their overlapping portions 6a in the circumferential direction C. Therefore, as shown in Fig. 4, the overlapping portions 6a of adjacent partial cores 2a fit together and are closely connected to each other via the overlapping portions 6a. Other points are the same as those in the first embodiment.

[0027] Fig. 6 shows a cylindrical core 1b according to a third embodiment of the present invention as viewed along the axial direction A (see Fig. 1). As shown in Fig. 6, the cylindrical core 1b includes a plurality of partial cores 2b similar to the partial cores 2a according to the second embodiment, which are connected in the circumferential direction C via overlapping portions 6b.

[0028] Fig. 7A shows how adjacent partial cores 2b are connected to each other via overlapping portions 6b. Fig. 7B shows how adjacent partial cores 2b are connected to each other via overlapping portions 6b and integrated. Figs. 7A and 7B show each state as viewed from the central axis of the cylindrical core 1b.

[0029] 7B, a through hole 8 is provided in the overlapping portion 6b between adjacent partial cores 2b, extending from one surface F1 to the other surface F2 of the cylindrical core 1b in the axial direction A. Adjacent partial cores 2b are inserted into the through hole 8 and connected by a pin (thin round steel) 9 extending from one surface F1 to the other surface F2.

[0030] 7A and 7B , the through holes 8 of the overlapping portions 6b of adjacent partial cores 2b are offset by a small central angle β in the circumferential direction C between the through hole 8 of one partial core 2b and the through hole 8 of the other partial core 2b. The direction of the offset is such that, when a pin 9 is inserted into the through hole 8, the intimate contact between the adjacent partial cores 2b in the circumferential direction C is strengthened.

[0031] Specifically, as shown in Figure 7A, the central angle formed by both end edges of the overlapping portion 6b of adjacent partial cores 2b in the circumferential direction C is 2α, and the position in the overlapping portion 6b between the both end edges and the both end edges that forms the central angle α is the reference position Pd in ​​the overlapping portion 6b.

[0032] In one overlapping portion 6b of adjacent partial cores 2b, a portion of its through hole 8 is provided on the reference position Pd, and in the other overlapping portion 6b, a portion of its through hole 8 is provided at a position shifted from the reference position Pd by a small central angle β toward the partial core 2b to which the other overlapping portion 6b belongs. Note that the small central angle β is exaggerated for ease of understanding.

[0033] In this case, adjacent partial cores 2b are fitted together at the overlapping portions 6b therebetween, thereby forming through holes 8 that are partially offset by the central angle β, as shown in Fig. 7B. By forcibly inserting a pin 9 into this through hole 8, both partial cores 2b are pressed with a force corresponding to the central angle β in directions that bring them closer together along the circumferential direction C, and both partial cores 2b are connected to each other.

[0034] According to this embodiment, adjacent partial cores 2b are closely connected in the circumferential direction C by pins 9 inserted into through holes 8 in the overlapping portions 6b. Therefore, it is possible to form the cylindrical core 1b without the need to hold each partial core 2b in a case 7 as in the first and second embodiments. In other respects, this embodiment is similar to the first and second embodiments.

[0035] Fig. 8 shows a cylindrical core 1c according to a fourth embodiment of the present invention as viewed along the axial direction A (see Fig. 1). Fig. 9A shows a cross section taken along line IX-IX in Fig. 8. As shown in Figs. 8 and 9A, in the cylindrical core 1c of this embodiment, the pin 9 inserted into the through hole 8 of the overlapping portion 6c of each partial core 2c has crushed portions 10 on both end faces of the pin 9 that are formed by being pressed and crushed in the length direction of the pin 9. The other configurations are the same as those of the third embodiment.

[0036] 9B shows a method for forming crushed portion 10. As shown in Fig. 9B, crushed portion 10 is provided by pressing the centers of both end faces of pin 9 inserted into through hole 8 along the length of pin 9 with protruding tool 11 to crush it.

[0037] Even when the pin 9 is designed so that both ends do not protrude from the opposite surfaces of the cylindrical core 1c, a slight amount of protrusion may occur within the tolerance. In this case, as shown in Fig. 9C, by using a tip end flat surface 12 having a protrusion at the tip of the protruding tool 11 that has a larger diameter than the pin 9, the tip end flat surface 12 can prevent the slight amount of protrusion from occurring when the crushed portion 10 is formed.

[0038] According to this embodiment, the bonding force between the pin 9 and the through hole 8 of the metal plate 3c at both ends thereof is increased, thereby strengthening the fastening force between the partial cores 2c. Therefore, the cylindrical core 1c can be formed without being housed in the case 7. Furthermore, by employing the tip flat surface 12 in the protruding tool 11, the pin 9 can be prevented from protruding, thereby improving the workability in the next step.

[0039] 6, in which the pin 9 does not have the crushed portion 10, both ends of the pin 9 may slightly protrude from both sides of the cylindrical core 1b within the tolerance. In this case, too, as shown in FIG. 9D, by using a tool 23 having a tip surface 22 composed of a single flat surface with no protrusions, the tip surface 22 of the tool 23 can be used to press both end surfaces of the pin 9 inserted into the through hole 8 of the overlapping portion 6b along the length of the pin 9, thereby preventing the slight protrusion from occurring.

[0040] Fig. 10 shows a cylindrical core 1d according to a fifth embodiment of the present invention as viewed along the axial direction A (see Fig. 1). Fig. 11 shows the shape of one end of a partial core 2d of the cylindrical core 1d in the circumferential direction. The cylindrical core 1d is characterized by the shape of the overlapping portion 6d between adjacent partial cores 2d.

[0041] That is, in the overlapping portion 6d of the partial core 2d, as shown in Figures 10 and 11, each metal plate 3d forming the partial core 2d has a shape such that one end and the other end corresponding to the overlapping portion 6d can be fitted together in the circumferential direction C and be in close contact with each other.

[0042] Therefore, adjacent partial cores 2d have their adjacent ends of both unit cores 4d forming an overlapping portion 6d between the partial cores 2d, and the unit cores 4d also overlap with each other at the overlapping portion 6d when viewed in the radial direction R.

[0043] That is, one and the other ends of each metal plate 3d constituting the overlapping portion 6d have a concave shape along the circumferential direction and a convex shape that fits into the concave shape. Therefore, one end of a unit core 4d formed by stacking several metal plates 3d has a concave shape along the circumferential direction and a recessed groove 13 extending in the axial direction A.

[0044] The other end of the unit core 4d has a ridge 14 that protrudes in a convex shape along the circumferential direction and extends in the axial direction A, and fits closely into the recessed groove 13. Furthermore, a through hole 8d and a pin 9d that have the same functions as the through hole 8 and pin 9 in the third and fourth embodiments are provided at the tip end portions on both sides of the recessed groove 13 and at the tip end portion of the ridge 14.

[0045] The front and rear ends of the recessed groove 13 and the protruding strip 14 may be provided with chamfered portions 15d at the protruding corners along the axial direction A and chamfered portions 24d at the corresponding protruding corners. This increases the contact area between the partial cores 2d in the circumferential direction C.

[0046] According to this embodiment, the partial cores 2d overlap in the radial direction R as well as in the axial direction A at the overlapping portions 6d, and are in close contact with each other over a wider contact area, thereby achieving better electrical conduction between the metal plates 3d adjacent in the circumferential direction C. In addition, the partial cores 2d can be more firmly connected to each other by the three pins 9 provided in the recessed grooves 13 and the protruding strips 14 of the overlapping portions 6d between the partial cores 2d.

[0047] Furthermore, when chamfered portions 15d are provided at the tips of the recessed grooves 13 and the protruding strips 14, the partial cores 2d can be easily connected to each other. Other points are the same as those in the third and fourth embodiments. Note that, although each unit core 4d has one recessed groove 13 and one protruding strip 14 in this embodiment, it is not limited to this and two or more of each may be provided.

[0048] Fig. 12A shows a portion of a cylindrical core 1e according to the sixth embodiment as viewed along the axial direction A (see Fig. 1). Fig. 12B shows the shape of one end of a partial core 2e of the cylindrical core 1e. As shown in Figs. 12A and 12B, the unit core 4e of each partial core 2e has two recessed grooves 13e in one overlapping portion 6e and two ridges 14e in the other overlapping portion 6e.

[0049] In this case as well, by providing chamfered portions 15d at the outside corners and chamfered portions 24d at the inside corners corresponding thereto, it is possible to increase the contact area between the partial cores 2e in the circumferential direction C. Other points are the same as in the fifth embodiment.

[0050] Fig. 13 shows a cylindrical core 1f according to a seventh embodiment of the present invention as viewed along the axial direction A (see Fig. 1). The cylindrical core 1f of this embodiment is housed in a cylindrical case 7. In the cylindrical core 1f, similar to the partial core 2d of Fig. 11, one overlapping portion 6f and the other overlapping portion 6f of each unit core 4f (see Fig. 14A) forming the partial core 2f each have a recessed groove 13 and a protruding rib 14 (see Fig. 11).

[0051] 14A to 14C show how adjacent partial cores 2f are connected using through holes 8f and pins 9f to form a cylindrical core 1f, as viewed from the central axis of the cylindrical core 1f.

[0052] As shown in Figures 14A to 14C, in this embodiment, through holes 8f and pins 9f with different diameters from the through holes 8d and pins 9d in Figures 10 and 11 are used as through holes and pins provided in the overlapping portion 6f to connect the partial cores 2f to each other.

[0053] That is, as shown in Figure 14A, if the central angle occupied by the overlapping portions 6f of adjacent partial cores 2f is 2θ, the central axis of the through hole 8f portion of each overlapping portion 6f is located at a position that forms a central angle (θ-γ) with the tip edge of each overlapping portion 6f.

[0054] Therefore, as shown in Figure 14B, when each partial core 2f is fitted together via the overlapping portion 6f to form through holes 8f aligned in the axial direction A, a gap of central angle 2γ is created between each partial core 2f.

[0055] Therefore, in this state, if a pin 9f having a diameter φN smaller than the diameter φM of the through hole 8f is inserted into the through hole 8f, by setting the value of the central angle γ to a value equivalent to φM-φN, the positional relationship between the partial cores 2f can be adjusted up to twice the central angle 2γ (=4γ).

[0056] For example, when the central angle 2γ is greater than (φM-φN), the adjacent partial cores 2f can be placed close to each other with a gap of approximately 2γ-(φM-φN).When the central angle 2γ is equal to or smaller than (φM-φN), the adjacent partial cores 2f can be placed close to each other as shown in FIG.

[0057] Therefore, by connecting multiple partial cores 2f via overlapping portions 6f and inserting pins 9f into the through holes 8f of each overlapping portion 6f to form a cylindrical shape, and then bringing adjacent partial cores 2f close to or in close contact with each other as described above, a cylindrical core 1f whose outer diameter is smaller than the inner diameter of the case 7 can be temporarily formed.

[0058] By placing this cylindrical core 1f inside the case 7 and separating adjacent partial cores 2f from each other, the diameter of the cylindrical core 1f can be expanded, forming a cylindrical core 1f that fits snugly inside the case 7.

[0059] According to this embodiment, while it is generally difficult to manufacture a cylindrical core in which multiple partial cores are closely connected and fit within the case 7, the diameter of the cylindrical core 1f can be adjusted to match the case 7, so that a cylindrical core 1f that fits and is stored within the case 7 can be easily manufactured.

[0060] In this case, the edges of adjacent partial cores 2f in the circumferential direction C are separated from each other, but even in this case, the overlapping portions 6f of both partial cores 2f overlap in the radial direction R and are closely adjacent, so that adjacent metal plates 3f in the circumferential direction are closely adjacent in the radial direction and are electrically conductive to each other.

[0061] Therefore, according to this embodiment, by appropriately setting the diameter φM of the through hole 8f, the diameter φN of the pin 9, and the position of the central axis of the through hole 8f portion in the overlapping portion 6f, it is possible to realize a cylindrical core 1f that fits and is stored within the case 7 while ensuring connection between the partial cores 2f and conductivity between the metal plates 3f in the circumferential direction C.

[0062] 15 is an explanatory diagram for explaining a partial core manufacturing device used to manufacture the partial cores 2, 2a according to the first and second embodiments described above. This partial core manufacturing device has a function (means) of feeding a steel plate 16, which is the material for the metal plate 3, in a traveling direction D, and a function (means) of performing predetermined press working on the steel plate 16 being fed in the traveling direction D at each of the working positions P1 to P6 to sequentially form the metal plate 3.

[0063] The traveling direction D coincides with the direction along the center line L1 extending radially of the arc shape 17 including the portion of the steel plate 16 that will become the overlapping portions 6, 6a of the metal plate 3. This arc shape 17 coincides with the shape of the partial cores 2, 2a when viewed along the axial direction A.

[0064] The partial core manufacturing device has a function of forming pilot holes 18 at processing position P1 to correct feed errors for each of the subsequent processing positions P2 to P6. The partial core manufacturing device also has a function of forming the shapes of the overlapping portions 6, 6a on both sides of the metal plate 3 at processing positions P2, P3.

[0065] That is, at processing position P2, one of the overlapping portions 6, 6a of the metal plate 3 is punched into the shape of the overlapping portion 6, 6a, while the other of the overlapping portions 6, 6a retains the shape of the overlapping portion 6, 6a. Also, at processing position P3, one of the overlapping portions 6, 6a of the metal plate 3 retains the shape of the overlapping portion 6, 6a, while the other of the overlapping portions 6, 6a is punched into the shape of the overlapping portion 6, 6a.

[0066] That is, at processing position P3, overlapping portions 6, 6a are formed in which the shapes of one overlapping portion 6, 6a and the other overlapping portion 6, 6a are interchanged with respect to the overlapping portions 6, 6a at processing position P2. Processing at processing position P2 or processing position P3 is performed by selecting either one depending on the stacking position of the metal plate 3 to be formed in the partial cores 2, 2a.

[0067] The partial core manufacturing device has a function of providing round holes 19 at the processing position P4 for crimping and stacking the metal sheets 3 to be formed. This function is performed when the metal sheets 3 to be formed are to be placed at the initial stacking position of the cylindrical cores 1, 1a.

[0068] The partial core manufacturing device has a function of providing, at processing position P5, crimps 5 (dowels; round protrusions) for stacking the metal plates 3 to be formed at the same positions as the positions of the above-mentioned round holes 19 on the metal plates 3. At processing position P6, the partial core manufacturing device has a function of cutting and separating the parts other than the overlapping parts 6, 6a from the steel plate 16 so as to form the shape of the metal plate 3, and sequentially stacking the metal plates 3 obtained by separation according to the round holes 19 and crimps 5.

[0069] When manufacturing partial cores 2, 2a using this partial core manufacturing apparatus, the steel plate 16 is fed in the traveling direction D (first step), and the portions of the steel plate 16 that will become the metal plates 3 are processed sequentially at each processing position P1 to P6.

[0070] That is, first, a pilot hole 18 is formed at processing position P1. Then, at processing positions P2 and P3, portions that will become the overlapping portions 6 and 6a on both sides of the metal plate 3 are formed. The overlapping portions 6 and 6a are formed so that the center line extending in the radial direction of the arc shape 17 including the portions of the metal plate 3 that will become the overlapping portions 6 and 6a coincides with a straight line L1 on the steel plate 16 that is parallel to the traveling direction D (second step).

[0071] When performing this second step, each time the formation of the overlapping portions 6, 6a of the metal plates 3 corresponding to the unit cores 4, 4a is completed, the shapes of the overlapping portions 6, 6a on both sides are alternated (third step).

[0072] That is, when the metal plate 3 to be formed is to be used for the partial core 2, the shape of the portions that become the overlapping portions 6 on both sides is alternated for each metal plate 3. Therefore, for each metal plate 3, punching out one overlapping portion 6 at processing position P2 and punching out the other overlapping portion 6 at processing position P3 are performed alternately.

[0073] On the other hand, if the metal plate 3 to be formed is to be used for a partial core 2a, and the unit core 4a of the partial core 2a is composed of four metal plates 3 as shown in Figure 5, then for every four metal plates 3, punching out one overlapping portion 6a at processing position P2 and the other overlapping portion 6a at processing position P3 are alternately performed.

[0074] At processing positions P4 and P5, if the metal plate 3 to be formed is the first to be laminated in the partial cores 2 and 2a, a round hole 19 is formed therein, and if it is the second or subsequent layer to be laminated, a crimp 5 is formed therein. Furthermore, at processing position P6, the metal plate 3 is punched out from the steel plate 16 (fourth step), and is laminated in order according to the round hole 19 and crimp 5, thereby forming the partial cores 2 and 2a (fifth step).

[0075] The partial core manufacturing apparatus of Figure 15 and the manufacturing method of partial cores 2, 2a using the same can also be applied to the manufacturing of partial cores 2b (see Figure 6), partial cores 2d (see Figure 10), partial cores 2e (see Figure 12A), and partial cores 2f (see Figure 14A) by adjusting the overlapping portions 6, 6a on both sides of the metal plate 3 formed at processing positions P2, P3 to correspond to the shapes of the respective overlapping portions 6b, 6d, 6e, 6f.

[0076] 16A to 16D show the procedure (sixth step) for connecting partial cores to form a cylindrical core, using the cylindrical core 1d in Fig. 10 as an example. When connecting cylindrical cores 1d to form the cylindrical core 1d, first, as shown in Fig. 16A, two partial cores 2d are connected by fitting them together at their overlapping portions 6d. Next, two sets of such connected cores are connected in the same manner as shown in Fig. 16B to form a core made up of four connected partial cores 2d.

[0077] Then, as shown in Fig. 16C, two sets of four partial cores 2d are connected together at both ends in the same manner, thereby forming a cylindrical core 1d as shown in Fig. 16D.

[0078] Note that cylindrical cores 1b, 1c, 1d, 1e, 1f, etc. shown in Figures 6, 8, 10, 12A, and 13 other than cylindrical core 1d can also be formed in a similar manner. In this case, in the case of cylindrical core 1b shown in Figure 6, adjacent cylindrical cores 1b can be easily fitted together by sliding them relative to each other in the radial direction R (see Figure 11). The same applies to cylindrical core 1c shown in Figure 8.

[0079] The present invention is not limited to the above-described embodiment. For example, the overlapping portions 6, 6a, and 6b of the partial cores 2, 2a, and 2b shown in Fig. 3, 5, and 7A, respectively, may be provided with chamfered portions 20 extending along the radial direction R of the cylindrical cores 1, 1a, and 1b, as shown in Fig. 17A to Fig. 17C.

[0080] The chamfered portions 20 are formed by chamfering the corners where the partial cores 2, 2a, and 2b pass each other when they are fitted together via the overlapping portions 6, 6a, and 6b, respectively. The chamfered portions 20 can be formed, for example, by crushing the corners of the metal plate 3 with a press die 21 in a press die when the metal plate 3 is pressed, as shown in Fig. 17D.

[0081] As a result, the chamfered portions 20 suppress interference between the corners where the partial cores 2, 2a, and 2b meet when they are fitted together via the overlapping portions 6, 6a, and 6b, respectively, so that the partial cores 2, 2a, and 2b can be connected together with good workability.

[0082] Furthermore, the techniques disclosed in the above-described embodiments can be applied to other embodiments within the scope of applicability. For example, the embodiment in which the pins 9 are used to connect the partial cores 2b in the third embodiment can be applied to connecting the partial cores 2 in the first embodiment or the partial cores 2a in the second embodiment. [Explanation of symbols]

[0083] 1, 1a, 1b, 1c, 1d, 1e, 1f... cylindrical core, 2, 2a, 2b, 2c, 2d, 2e, 2f... partial core, 3, 3b, 3d, 3e, 3f... metal plate, 4, 4a, 4b, 4d, 4e, 4f... unit core, 5... crimp, 6, 6a, 6b, 6d, 6e, 6f... overlapping portion, 7... case, 8, 8d, 8f... through hole, 9, 9d, 9f... pin, 10... crushed portion, 11... protruding tool, 12... tip flat surface, 13, 13e... concave groove, 14, 14e... convex rib, 15d, 24d... chamfered portion, 16... steel plate, 17... arc shape, 18... pilot hole, 19... round hole, 20... chamfered portion, 21... press die, L1... center line, P1 to P6... processing position.

Claims

1. A cylindrical core having a plurality of partially cylindrical partial cores connected in a circumferential direction thereof, Each partial core includes a plurality of unit cores, each of which has one or more laminated metal plates having the same outer circumferential shape, stacked in the axial direction of the cylindrical core while changing the position of each unit core so that both end edges in the circumferential direction are interchanged, The partial cores adjacent to each other have overlapping portions where each unit core of one partial core overlaps with each unit core of the other partial core when viewed in the axial direction, The partial cores are closely connected to each other via the overlapping portions, the overlapping portion between adjacent partial cores includes through holes extending from one surface to the other surface in the axial direction of the cylindrical core, and pins inserted into the through holes and extending from the one surface to the other surface, A cylindrical core characterized in that adjacent partial cores are closely connected at the overlapping portion between the two partial cores by each unit core of one partial core and each unit core of the other partial core being alternately subjected to forces in one and the other circumferential directions via the pin inserted into the through hole.

2. when viewed in the axial direction, both end edges in the circumferential direction of each unit core form two straight lines that form a predetermined central angle with the central axis of the cylindrical core as the center, In the adjacent partial cores, In one of the partial cores, the circumferential position of each unit core is repeatedly displaced by a predetermined amount in one direction and the other direction each time the two end edges are switched, In the other partial core, the circumferential position of each unit core is repeatedly displaced by the predetermined amount in a direction opposite to that of the one partial core each time the two end edges are switched, 2. The cylindrical core according to claim 1, wherein the predetermined amount coincides with the central angle occupied by the overlapping portions between the adjacent partial cores.

3. the metal plate has a shape such that both end portions can be fitted together in the circumferential direction and come into close contact with each other, 2. The cylindrical core according to claim 1, wherein the adjacent ends of the partial cores of the unit cores form the overlapping portion between the partial cores.

4. 4. The cylindrical core according to claim 1, wherein each partial core has a chamfered portion for facilitating mutual connection via the overlapping portion.

5. 2. The cylindrical core according to claim 1, wherein the pin has crushed portions formed on both end surfaces thereof by being pressed in the length direction of the pin.

6. A cylindrical core having a plurality of partially cylindrical partial cores connected together in the circumferential direction thereof, Each partial core includes a plurality of unit cores, each of which has one or more laminated metal plates having the same outer circumferential shape, stacked in the axial direction of the cylindrical core while changing the position of each unit core so that both end edges in the circumferential direction are interchanged, The partial cores adjacent to each other have overlapping portions where each unit core of one partial core overlaps with each unit core of the other partial core when viewed in the axial direction, The partial cores are closely connected to each other via the overlapping portions, the overlapping portion between adjacent partial cores includes a through hole extending from one surface to the other surface in the axial direction of the cylindrical core, and a pin inserted into the through hole and extending from the one surface to the other surface, The pin has crushed portions formed by pressing the pin in the length direction at both end surfaces of the pin, a method for manufacturing a cylindrical core, characterized in that the crushed portion is formed by using a tool having a tip plane with a diameter larger than that of the pin and a protrusion at the center of the tip plane to press the centers of both end faces of the pin along the length of the pin and crush it.

Images