Manufacturing method of laminated iron core, laminated iron core and motor

Abstract

A manufacturing method is provided that can improve the manufacturing efficiency of a cylindrical laminated core formed by deforming a strip-shaped core piece forming member and winding it spirally. [Solution] The process includes a punching process in which a core piece forming member 81-1 having a back yoke portion 21 and a plurality of tooth portions 22 is formed by punching out a plate-shaped steel plate; a stacking process in which the core piece forming member is deformed to one side in the width direction and wound spirally, and the back yoke portion and tooth portions are stacked and laminated in the axial direction; a first cutting process in which, when viewed in the axial direction, the core piece forming member stacked in the axial direction is cut in the width direction at a position a first distance behind the winding start end 81a of the core piece forming member, thereby forming a winding end on the core piece forming member; and a second cutting process in which, when viewed in the axial direction, the core piece forming member is cut in the width direction at a position overlapping the winding start end, thereby forming the winding start end of the core piece forming member to be wound next spirally.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a laminated core, a laminated core, and a motor. [Background technology]

[0002] There is known a manufacturing method for manufacturing a laminated core by winding a strip-shaped core piece forming member while deforming it into a spiral shape. For example, Patent Document 1 discloses a method for manufacturing the laminated core using a laminated core manufacturing device that includes a forming unit that feeds and shapes the sheet material to be processed, a winding unit that winds up the sheet material processed by the forming unit, and a cutting unit that cuts the wound sheet material at predetermined positions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-35598 Summary of the Invention [Problem to be solved by the invention]

[0004] A laminated core, in which plate-shaped steel plates are stacked, has multiple connecting portions that connect the stacked steel plates in the stacking direction. Also, a laminated core formed by a core piece forming member that is wound while being deformed into a spiral shape has the connecting portions located near the ends of the core piece forming member in the extension direction to prevent the ends from curling up.

[0005] It is desirable that the multiple connecting portions be arranged as evenly as possible in the circumferential direction. Therefore, in the laminated core, it is desirable that the circumferential positions of the winding start end and the winding end of the core piece forming member are separated in the circumferential direction. In this case, the position of the winding start end of the core piece forming member changes for each laminated core manufactured. Therefore, in a later process during manufacturing, it is necessary to align the winding start end for each laminated core, which reduces the manufacturing efficiency of laminated cores.

[0006] An object of the present invention is to provide a manufacturing method capable of improving the manufacturing efficiency of a cylindrical laminated core formed by deforming and spirally winding a strip-shaped core piece forming member. [Means for solving the problem]

[0007] A method for manufacturing a laminated core according to one embodiment of the present invention is a method for manufacturing a laminated core in which a core piece forming member extending in a band shape in one direction is deformed to one side in the width direction and wound spirally to produce a cylindrical laminated core extending in the axial direction. The manufacturing method of a laminated core includes a punching process in which the core piece forming member having a plate-shaped back yoke portion extending in one direction and a plurality of tooth portions extending from one side of the back yoke portion in the width direction to one side of the width direction is formed by punching out a plate-shaped steel plate; a stacking process in which the core piece forming member is deformed to one side in the width direction and wound spirally, and the back yoke portion and the tooth portions are stacked and stacked in the axial direction; a first cutting process in which the core piece forming member stacked in the axial direction is cut in the width direction at a position a first distance rearward in the winding direction from the winding start end of the core piece forming member when viewed in the axial direction, thereby forming a winding end on the core piece forming member; and a second cutting process in which the core piece forming member is cut in the width direction at a position overlapping the winding start end when viewed in the axial direction, thereby forming the winding start end of the core piece forming member to be wound spirally next.

[0008] A laminated core according to one embodiment of the present invention is a cylindrical laminated core extending in the axial direction, in which core pieces each having a plate-shaped back yoke portion extending in a spiral shape around a central axis and a plurality of teeth protruding radially inward from the back yoke portion are stacked in a state where the back yoke portion and the teeth portion overlap in the thickness direction. The core pieces have one side end portion formed by cutting at one end in the extension direction, and another side end portion formed by cutting at the other end in the extension direction. The laminated core has a portion between the one side end portion and the other side end portion where the number of laminated core pieces is one less in the axial direction, in a direction opposite to a first direction from the one side end portion to the other side end portion of the core piece.

[0009] A motor according to one embodiment of the present invention includes a stator having the laminated core and a coil wound around the laminated core, and a rotor disposed radially inward of the stator. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a manufacturing method that can improve the manufacturing efficiency of a cylindrical laminated core that is formed by deforming and spirally winding a strip-shaped core piece forming member. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a laminated core according to the first embodiment. [Figure 2] FIG. 2 is a plan view of the laminated core. [Figure 3] FIG. 3 is a diagram illustrating a schematic configuration of the core piece. [Figure 4] FIG. 4 is a punched view of the steel plate. [Figure 5] FIG. 5 is a plan view of the core piece forming member. [Figure 6] FIG. 6 is a diagram showing the state of the core piece forming member before being bent into an arc shape. [Figure 7] FIG. 7 is a diagram showing a state in which the core piece forming member is bent into an arc shape. [Figure 8] FIG. 8 is a diagram showing a state in which the core piece forming member is wound in a spiral shape. [Figure 9] FIG. 9 is a diagram illustrating the first cutting step. [Figure 10] FIG. 10 is a diagram illustrating the second cutting step. [Figure 11] FIG. 11 is a diagram illustrating the joining step. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and their description will not be repeated. Furthermore, the dimensions of the components in each drawing do not faithfully represent the actual dimensions of the components and the dimensional ratios of the components.

[0013] In the following description, the direction parallel to the central axis P of the laminated core 1 is referred to as the axial direction, the direction perpendicular to the central axis P as the radial direction, and the direction along the arc centered on the central axis P as the circumferential direction. Furthermore, within the circumferential direction, the direction from one end 2a of the core piece 2 toward the other end 2b is referred to as the first direction, and the opposite direction as the second direction. However, these definitions of the directions are not intended to limit the orientation of the laminated core 1 according to the present invention during use. In each drawing, the axial direction is indicated by A, and the circumferential direction is indicated by C. Furthermore, within the circumferential direction, the first direction is indicated by C1, and the second direction is indicated by C2.

[0014] Furthermore, in the following description, expressions such as "fix," "connect," "join," and "attach" include not only cases where members are directly fixed to each other, but also cases where members are fixed to each other via other members. In other words, in the following description, expressions such as "fix" include both direct and indirect fixation of members to each other.

[0015] (Laminated core configuration) An example of a laminated core 1 according to an embodiment will be described with reference to Figures 1 to 3. The laminated core 1 is, for example, a stator core of a motor. The motor has, for example, a stator having the laminated core 1 and a coil wound around the laminated core 1, and a rotor disposed radially inward of the stator. The configuration of the motor is similar to that of a general motor, so a description thereof will be omitted.

[0016] Fig. 1 is a perspective view showing the schematic configuration of a laminated core 1. Fig. 2 is a plan view of the laminated core 1. For the sake of explanation, Fig. 2 shows the vicinity of both ends of the core piece 2 in the extension direction separated from adjacent portions in the lamination direction. Fig. 3 is a diagram illustrating the schematic configuration of the core piece 2.

[0017] As shown in FIG. 1 , the laminated core 1 extends in the axial direction A around a central axis P. The laminated core 1 has a back yoke 11 and a plurality of teeth 12. The back yoke 11 is cylindrical and extends in the axial direction A around the central axis P. The plurality of teeth 12 extend radially inward from the inner end face of the back yoke 11. The plurality of teeth 12 are aligned in the circumferential direction C. Coils (not shown) are wound around the plurality of teeth 12. In this embodiment, the laminated core 1 has 36 teeth 12. Note that the laminated core may have more or fewer than 36 teeth.

[0018] The main body of the laminated core 1 is formed by a single plate-shaped core piece 2 that is spirally wound around a central axis P and laminated in an axial direction A. The laminated core 1 has a plurality of connecting portions 3 and a circumferential positioning portion 4.

[0019] As shown in Fig. 3, the core piece 2 extends in a spiral shape around the central axis P. As shown in Figs. 1 and 2, the core piece 2 has one end 2a located at one end in the extension direction and another end 2b located at the other end in the extension direction. In Figs. 1 and 2, the one end 2a is located downward.

[0020] The core piece 2 has a plate-shaped back yoke portion 21 and a plurality of plate-shaped teeth 22. The back yoke portion 21 extends in a spiral shape centered on a central axis P. The plurality of teeth 22 extend radially inward from an end face on the inner peripheral side of the back yoke portion 21. The plurality of teeth 22 are aligned in the circumferential direction C.

[0021] The core pieces 2 are stacked with the back yoke portions 21 and the teeth portions 22 overlapping in the thickness direction. The back yoke portions 21 stacked in the thickness direction form the back yoke 11 of the laminated core 1. The multiple tooth portions 22 stacked in the thickness direction form the teeth 12 of the laminated core 1.

[0022] The core pieces 2 are formed by punching out a plate-shaped electromagnetic steel sheet, which is the material for the core pieces 2, to form a strip-shaped core piece forming member 81, and then winding the core piece forming member 81 spirally in the thickness direction. One side end 2a and the other side end 2b of the core piece 2 are formed by cutting the strip-shaped core piece forming member 81 at predetermined positions. In this embodiment, the one side end 2a is the winding start end 81a when winding the core piece forming member 81 spirally, and the other side end 2b is the winding end end 81b when winding the core piece forming member 81 spirally. The manufacturing method of the laminated core 1 will be described in detail later.

[0023] The circumferential position of one end 2a of the core piece 2 is different from the circumferential position of the other end 2b. Therefore, the core piece 2 has a portion 1a between the one end 2a and the other end 2b in the second direction C2 where the number of laminated layers of the core piece 2 is one less. The second direction C2 is the opposite direction to the first direction C1 which runs from the one end 2a to the other end 2b of the core piece 2. In Figures 1 and 2, the range of the portion 1a where the number of laminated layers of the core piece 2 is one less is indicated by R1.

[0024] 2, in the laminated core 1, the portion 1a where the number of laminated core pieces 2 is one less is smaller than the other portions. That is, the central angle D of the portion 1a where the number of laminated core pieces 2 is one less is less than 180 degrees. This allows a laminated core 1 to be obtained in which the portion with the short length in the axial direction A is small.

[0025] The multiple connecting portions 3 extend in the stacking direction on the radially outer end surfaces of the laminated core 1. The multiple connecting portions 3 connect the back yoke portions 21 in the stacking direction. The multiple connecting portions 3 are obtained by joining the radially outer portions of the core pieces 2 in the stacking direction. For example, the multiple connecting portions 3 are obtained by welding the radially outer portions of the core pieces 2 along the axial direction A. The core pieces may have recesses extending in the stacking direction at positions on the radially outer end surfaces of the core pieces where the connecting portions 3 are to be formed. In this case, the connecting portions may be obtained by welding along the recesses.

[0026] In this embodiment, the laminated core 1 has six connecting portions 3. One of the six connecting portions 3, a first connecting portion 3a, is located radially outward from the tooth portion 22a that is closest to one end portion 2a of the core segment 2 when viewed in the axial direction A. The other of the six connecting portions 3, a second connecting portion 3b, is located radially outward from the tooth portion 22b that is closest to the other end portion 2b of the core segment 2 when viewed in the axial direction A.

[0027] That is, the multiple connecting portions 3 include a first connecting portion 3a located on the radially outer end face of the tooth portion 22a closest to one side end 2a of the core piece 2, and a second connecting portion 3b located on the radially outer end face of the tooth portion 22b closest to the other side end 2b of the core piece 2.

[0028] This makes it possible to obtain a laminated core 1 in which the core pieces 2 are joined in the lamination direction at positions close to one end and the other end in the extension direction of the core pieces 2.

[0029] In this embodiment, the laminated core 1 has at least three connecting portions 3 arranged in the circumferential direction C. The second connecting portion 3b is adjacent to the first connecting portion 3a in the second direction C2.

[0030] The second connecting portion 3b is located on an end surface radially outward of the tooth portion 22b that is closest to the other end portion 2b of the core piece 2. The first connecting portion 3a is located on an end surface radially outward of the tooth portion 22a that is closest to the one end portion 2a of the core piece 2. As described above, the core piece 2 has a portion 1a between the one end portion 2a and the other end portion 2b in the second direction C2 where the number of laminated layers of the core piece 2 is one less.

[0031] Therefore, with the above-described configuration, the portion 1a where the number of laminated layers is one less can be made smaller, thereby making it possible to obtain a laminated core 1 where the portion having a short length in the axial direction A is small.

[0032] The circumferential positioning portion 4 extends in the lamination direction on the radially outer end face of the laminated core 1. The circumferential positioning portion 4 positions the laminated core 1 in the circumferential direction. In this embodiment, the circumferential positioning portion 4 is a recess. For example, by inserting a protrusion installed on a placement stand on which the laminated core 1 is placed into the recess, the laminated core 1 can be positioned in the circumferential direction relative to the placement stand.

[0033] In this embodiment, the circumferential positions of the one end 2a and the other end 2b of the core piece 2 are determined based on the circumferential position of the circumferential positioning portion 4. Therefore, in all laminated cores 1 manufactured by the manufacturing method for the laminated core 1 described below, the position of the one end 2a and the position of the other end 2b relative to the circumferential positioning portion 4 coincide when viewed in the axial direction A.

[0034] (Laminated core manufacturing method) Next, an exemplary method for manufacturing the laminated core 1 having the above-described configuration will be described with reference to Figs. 4 to 11. Fig. 4 is an example of a punched view of a steel plate 80. Fig. 5 is a plan view of a core piece forming member 81. Figs. 6 to 8 are views illustrating the lamination step. Fig. 9 is a view illustrating the first cutting step. Fig. 10 is a view illustrating the second cutting step. Fig. 11 is a view illustrating the joining step.

[0035] For ease of explanation, the region of the core piece forming member 81 that forms the boundary between circumferentially adjacent tooth portions 22 will be referred to as the core piece region R2. In each drawing, the core piece region R2 located at the winding start end 81a of the core piece forming member 81 is indicated by the number 1, and numbers are assigned in ascending order in the winding direction W. In addition, the same number is assigned to adjacent core piece regions R2 in the laminated core 1 in the lamination direction.

[0036] The manufacturing method of the laminated core 1 is a method of manufacturing a cylindrical laminated core 1 extending in the axial direction A around a central axis P by deforming a core piece forming member 81 extending in a strip shape in one direction to one side in the width direction and winding it spirally.

[0037] Specifically, the manufacturing method of the laminated core 1 includes a punching step, a laminating step, a first cutting step, a second cutting step, and a joining step.

[0038] In the punching process, a strip-shaped steel plate 80, which is a magnetic material, is punched to form a strip-shaped core piece forming member 81. The punching process is performed by press working. A detailed description of the press working will be omitted.

[0039] In the punching process, the shaded areas in Fig. 4 are punched out using a punch to form core piece forming members 81 having a back yoke portion 21, multiple teeth portions 22, multiple recesses 83, and circumferential positioning portions 4. The core piece forming members 81 are portions that will become the core pieces 2 of the laminated core 1. The multiple recesses 83 are portions that will become the connecting portions 3 of the laminated core 1.

[0040] 5, back yoke portion 21 formed by the punching process is in the shape of a strip extending in the longitudinal direction of steel plate 80. Multiple teeth portions 22 extend in the width direction from one side in the width direction of back yoke portion 21. The width direction of back yoke portion 21 is a direction that intersects with the longitudinal direction.

[0041] The core piece forming member 81 formed in the punching process includes a plurality of core piece forming members 81-1, 81-2, ... 81-n, which will each become a core piece 2 of the laminated core 1. As will be described in detail later, the core piece forming member 81 formed in the punching process is cut at a position that will become the winding start end 81a and a position that will become the winding end end 81b of the core piece forming member 81 formed in the punching process, thereby forming the core piece forming member 81 that will become one core piece 2.

[0042] One longitudinal end of the core piece forming member 81 formed in the punching process becomes the winding start end 81a of the core piece forming member 81. In this embodiment, the winding start end 81a of the core piece forming member 81 becomes one side end 2a of the core piece 2 in the laminated core 1.

[0043] The multiple recesses 83 are located at the other widthwise end of the back yoke portion 21. In this embodiment, the multiple recesses 83 are located in the first core piece region R2 closest to the winding start end 81a of the core piece forming member 81, and in the core piece regions R2 located every sixth region R2 in the winding direction W away from the first core piece region R2.

[0044] Specifically, in this embodiment, one recess 83 is formed in each of the first core piece region R2, the seventh core piece region R2, the thirteenth core piece region R2, the nineteenth core piece region R2, the twenty-fifth core piece region R2, and the thirty-first core piece region R2. However, the number and positions of the recesses are not limited to this. It is desirable that the positions of the recesses be equally spaced in the winding direction W. It is desirable that there are three or more recesses between the first core piece region R2 and the next first core piece region R2.

[0045] Of the multiple recesses 83, the first recess 83a formed in the first core piece region R2 is located at the other end of the back yoke portion 21 in the width direction relative to the tooth portion 22a that is closest to the position that becomes the winding starting end 81a in the core piece forming member 81.

[0046] In this embodiment, the second recess 83b adjacent to the first recess 83a on the rear side in the winding direction W is formed in the 31st core piece region R2. The front boundary in the winding direction W of the 31st core piece region R2 is the winding end end 81b of the core piece forming member 81. In other words, the recess 83 formed in the 31st core piece region R2 is located at the other end in the width direction of the back yoke portion 21 with respect to the tooth portion 22b that is closest to the position that becomes the winding end end 81b of the core piece forming member 81.

[0047] In this embodiment, the recesses 83 are formed in the core piece regions R2 spaced apart every six recesses 83. Therefore, in the core piece forming member 81 in a spirally wound state, the central angle between adjacent recesses 83 in the circumferential direction is 60 degrees.

[0048] In the lamination process, the core piece forming member 81 is deformed to one side in the width direction and wound spirally, and the back yoke portion 21 and the teeth portion 22 are stacked in the axial direction A.

[0049] Specifically, as shown in Figure 6, the radially inner end face of the tooth portion 22a closest to the winding start end 81a of the core piece forming member 81 is brought into contact with the outer peripheral surface of a columnar winding jig T1 extending in the axial direction A along the central axis Q.

[0050] 7 and 8, the core piece forming member 81 is wound around the outer peripheral surface of a winding jig T1. In the stacking process, the core piece regions R2 with the same number are stacked in the thickness direction. This forms the core piece forming member 81 in which the back yoke portion 21 extending spirally about the central axis Q and the multiple tooth portions 22 extending radially inward are stacked in the thickness direction.

[0051] In the first cutting step, a winding end 81b is formed in the core piece forming member 81. Specifically, as shown in FIG. 9, the core piece forming member 81 stacked in the axial direction A is cut in the width direction at position CT1. Position CT1 is a position that is a first distance L1 rearward in the winding direction W from the winding start end 81a of the core piece forming member 81. This forms a core piece forming member 81-1 that will become the core piece 2 of one laminated core 1. The winding end 81b formed in the first cutting step becomes the other end 2b of the core piece 2 in the laminated core 1.

[0052] The spiral core segment forming member 81-1 has a portion where the number of laminated steel sheets 80 is one less between the winding end 81b and the winding start end 81a in the winding direction W. This portion becomes the portion 1a where the number of laminated steel sheets 2 is one less.

[0053] In this embodiment, position CT1 is a position at a central angle D of less than 180 degrees from the position of the winding start end 81a when viewed in the axial direction A. Specifically, in this embodiment, position CT1 is the boundary between the 31st core piece region R2 in which the second recess 83b is formed and the 32nd core piece region R2.

[0054] In the second cutting step, a winding start end 81a of the core piece forming member 81-2 to be spirally wound next is formed. Specifically, as shown in Fig. 10, in the second cutting step, the core piece forming member 81 is cut in the width direction at a position CT2 that overlaps with the winding start end 81a of the core piece forming member 81-1 formed immediately before, as viewed in the axial direction A. This forms the winding start end 81a of the core piece forming member 81-2 to be spirally wound next. The winding start end 81a formed in the second cutting step becomes one side end 2a of the core piece 2 in the laminated core 1.

[0055] Therefore, in all laminated cores 1 manufactured by the manufacturing method of the laminated core 1, the circumferential positions of the winding start end 81a, the winding end end 81b, and the circumferential positions of the multiple recesses 83 are the same.

[0056] In the joining step, the back yoke portions 21 of the core piece forming members 81 that have been stacked in the axial direction A in the stacking step are joined together in the stacking direction to connect them together.

[0057] Specifically, the back yoke portion 21 is welded in the stacking direction at the positions of the multiple recesses 83. The method for joining the back yoke portion in the stacking direction is not limited to a specific method. For example, as shown in FIG. 11 , the back yoke portion may be joined in the stacking direction using a welding device T2 that is arranged radially outward from the multiple recesses 83. For example, the back yoke portion may be joined in the stacking direction by rotating the core piece forming member around its central axis and sequentially positioning the multiple recesses at the welding positions where the welding device T2 is located.

[0058] Through the above steps, the laminated core 1 is manufactured.

[0059] As described above, the manufacturing method of the exemplary laminated core 1 according to this embodiment is a manufacturing method of the laminated core 1 in which the core piece forming member 81 extending in one direction like a strip is deformed to one side in the width direction and wound in a spiral shape to manufacture the cylindrical laminated core 1 extending in the axial direction A. The manufacturing method of the laminated core 1 includes a punching step, a laminating step, a first cutting step, and a second cutting step.

[0060] In the punching process, core piece forming members 81 having plate-shaped back yoke portions 21 extending in one direction and a plurality of teeth portions 22 extending in one direction in the width direction from one side of back yoke portion 21 in the width direction are formed by punching out plate-shaped steel plate 80. In the laminating process, core piece forming members 81 are deformed toward one side in the width direction and wound spirally, and back yoke portions 21 and teeth portions 22 are stacked one on top of the other in the axial direction A.

[0061] In the first cutting step, when viewed in the axial direction A, the core piece forming members 81 stacked in the axial direction A are cut in the width direction at a position CT1 that is a first distance L1 behind the winding start end 81a of the core piece forming members 81 in the winding direction W, thereby forming a winding end 81b in the core piece forming members 81. In the second cutting step, when viewed in the axial direction A, the core piece forming members 81 are cut in the width direction at a position CT2 that overlaps with the winding start end 81a, thereby forming the winding start end 81a of the core piece forming member 81 that will be wound spirally next.

[0062] With this manufacturing method, the winding start ends 81a and winding end ends 81b of the core piece forming members 81 can be positioned in the same position in all manufactured laminated cores 1. Therefore, for example, in a process of joining the winding start ends 81a and winding end ends 81b, the winding start ends 81a and winding end ends 81b can be easily positioned at the joining position. In other words, there is no need to adjust the positions of the winding start ends 81a and winding end ends 81b for each core piece forming member 81 on the work bench or equipment used in subsequent processes. This improves the manufacturing efficiency of the laminated core 1.

[0063] Furthermore, the positions of the winding start end 81a and the winding end end 81b are the same for all laminated cores 1 manufactured by this manufacturing method. Therefore, for example, when manufacturing a motor having the laminated core 1, there is no need to adjust the circumferential position of each laminated core 1 in the equipment used to manufacture the motor. Therefore, manufacturing the laminated core 1 by the above-mentioned manufacturing method can improve the manufacturing efficiency of motors having the laminated core 1.

[0064] In this embodiment, in the first cutting process, the core piece forming member 81 is cut in the width direction at a position CT1 that is rearward of the winding starting end 81a of the core piece forming member 81 in the winding direction W and that is at a central angle of less than 180 degrees from the position of the winding starting end 81a when viewed in the axial direction A.

[0065] This manufacturing method allows for the manufacture of a laminated core 1 in which the winding end 81b is located at a central angle of less than 180 degrees rearward in the winding direction W from the winding start end 81a when viewed in the axial direction A.

[0066] The steel sheet 80 between the winding end 81b of one core piece forming member 81 and the winding start end 81a of the next core piece forming member 81 becomes scrap. Therefore, with the above-described manufacturing method, scrap can be reduced compared to when the winding end 81b is located at a central angle of 180 degrees or more behind the winding start end 81a in the winding direction W, as viewed in the axial direction A. This makes it possible to improve the product yield rate relative to the material.

[0067] In this embodiment, the manufacturing method of the laminated core 1 further includes a joining step of joining, in the stacking direction, the back yoke portions 21 of the core piece forming members 81 that have been stacked in the axial direction A in the stacking step. Also, in the punching step, first recesses 83a are formed in the end portion on the other side in the width direction of the back yoke portion 21 for the tooth portions 22a that are closest to the position that will become the winding start end 81a in the core piece forming member 81, and second recesses 83b are formed in the end portion on the other side in the width direction of the back yoke portion 21 for the tooth portions 22b that are closest to the position that will become the winding end end 81b in the core piece forming member 81. In the joining step, the back yoke portions 21 of the core piece forming members 81 that have been stacked in the axial direction A in the stacking step are joined in the stacking direction at the positions of the first recesses 83a and the second recesses 83b.

[0068] This makes it possible to form a core piece forming member 81 having a first recess 83a near the winding start end 81a and a second recess 83b near the winding end 81b. The core piece forming members 81 are joined in the stacking direction at the first recess 83a and the second recess 83b. Therefore, it is possible to obtain a laminated core 1 that is joined in the stacking direction at positions close to the winding start end 81a and positions close to the winding end 81b.

[0069] This eliminates the need for steps such as cutting the portions of the core piece forming members 81 between the joint and the winding start end 81a and between the joint and the winding end 81b, or fixing these portions to the portions of the core piece forming members 81 that overlap in the stacking direction, thereby improving the manufacturing efficiency of the laminated core 1.

[0070] The laminated core 1 manufactured by the above-described manufacturing method is a cylindrical laminated core 1 extending in the axial direction A, in which core pieces 2 each having a plate-shaped back yoke portion 21 extending in a spiral shape around the central axis P and a plurality of teeth 22 protruding radially inward from the back yoke portion 21 are stacked in a state where the back yoke portion 21 and the teeth 22 overlap in the thickness direction. The core pieces 2 have one end portion 2a formed by cutting at one end in the extension direction, and another end portion 2b formed by cutting at the other end in the extension direction. The laminated core 1 has a portion 1a where the number of laminated core pieces 2 is one less between the one end portion 2a and the other end portion 2b in a direction C2 opposite to a first direction C1 from the one end portion 2a toward the other end portion 2b of the core piece 2 as viewed in the axial direction A.

[0071] The laminated core 1 having the above-described configuration is manufactured by a manufacturing method for the laminated core 1. With this manufacturing method, the winding start ends 81a and winding end ends 81b of all core piece forming members 81 manufactured by this manufacturing method can be positioned in the same position. Therefore, for example, in a process of joining the winding start ends 81a and winding end ends 81b, the winding start ends 81a and winding end ends 81b can be easily positioned at the joining positions. This improves the manufacturing efficiency of the laminated core 1. Therefore, it is possible to obtain a laminated core 1 that can be manufactured by a manufacturing method with improved manufacturing efficiency.

[0072] In the laminated core 1 manufactured by the above-described manufacturing method, the central angle D of the portion 1a where the number of laminated core segments 2 is one less is less than 180 degrees.

[0073] The above-described manufacturing method can reduce the amount of steel plate 80 that becomes scrap material. This can improve the product yield rate relative to the material. This allows for the production of a laminated core 1 that can be manufactured using a manufacturing method with an improved yield rate.

[0074] The laminated core 1 manufactured by the above-described manufacturing method has a plurality of connecting portions 3 that extend in the axial direction A on the radially outer end faces and connect the back yoke portions 21 in the stacking direction. The plurality of connecting portions 3 include first connecting portions 3a that are located on the radially outer end faces of the teeth 22a that are closest to one end 2a of the core pieces 2, and second connecting portions 3b that are located on the radially outer end faces of the teeth 22b that are closest to the other end 2b of the core pieces 2.

[0075] The multiple connecting portions 3 are obtained by, for example, welding multiple recesses 83 formed in the core piece forming member 81 in the axial direction A using the manufacturing method of the laminated core 1. The first connecting portions 3a are located on the radially outer end surface of the tooth portion 22a that is closest to the winding start end 81a of the core piece forming member 81. The second connecting portions 3b are located on the radially outer end surface of the tooth portion 22b that is closest to the winding end end 81b of the core piece forming member 81.

[0076] Therefore, when manufacturing the laminated core 1, there is no need to cut the portions of the core piece forming members 81 between the joint and the winding start end 81a and between the joint and the winding end 81b, or to fix these portions to the portions of the core piece forming members 81 that overlap in the lamination direction. This improves the manufacturing efficiency of the laminated core 1. This makes it possible to obtain a laminated core 1 that can be manufactured using a manufacturing method with improved manufacturing efficiency.

[0077] Furthermore, the laminated core 1 has at least three connecting portions 3 arranged in the circumferential direction C of the laminated core 1. The second connecting portion 3b is adjacent to the first connecting portion 3a in a direction C2 opposite to the first direction C1.

[0078] This allows the portion 1a where the number of laminated layers is one less to be smaller. Therefore, it is possible to obtain a laminated core 1 where the portion with a short length in the axial direction A is small. Therefore, it is possible to obtain a laminated core 1 where the portion with a short length in the axial direction A is small, and which can be manufactured using a manufacturing method with improved manufacturing efficiency.

[0079] The exemplary motor according to this embodiment also includes a stator having a laminated core 1 and a coil wound around the laminated core 1, and a rotor disposed radially inward of the stator.

[0080] This makes it possible to obtain a motor having a laminated core 1 that can be manufactured by a manufacturing method with improved manufacturing efficiency. Furthermore, the positions of the winding start end 81a and the winding end end 81b of all laminated cores 1 manufactured by the above-mentioned manufacturing method are the same. Therefore, in the process of manufacturing a motor having a laminated core 1, it is not necessary to adjust the circumferential position of each laminated core 1 using equipment, etc., used to manufacture the motor. This improves motor manufacturing efficiency. Therefore, it is possible to obtain a motor that can be manufactured by a manufacturing method with improved manufacturing efficiency.

[0081] (Other embodiments) Although the embodiments of the present invention have been described above, the above-described embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to the above-described embodiments, and it is possible to appropriately modify the above-described embodiments within the scope of the spirit of the present invention.

[0082] In the above embodiment, the laminated cores 1 are connected in the stacking direction by connecting portions 3 extending in the stacking direction on their radially outer end faces. However, the laminated cores may be connected in the stacking direction by other methods. For example, the laminated cores may be connected in the stacking direction by connecting portions extending in the stacking direction on their radially inner end faces. The laminated cores may be connected in the stacking direction by adhesive applied between overlapping regions of the core pieces in the stacking direction. The laminated cores may also be connected in the stacking direction by axial crimping.

[0083] In the above embodiment, the laminated core 1 has six connecting portions 3. However, the laminated core may have fewer than six connecting portions. It may also have more than six connecting portions. It is preferable that the laminated core has at least three connecting portions. This ensures the connecting strength of the laminated core in the lamination direction.

[0084] In the above embodiment, the second connecting portion 3b is adjacent to the first connecting portion 3a in the second direction C2. However, the second connecting portion does not have to be adjacent to the first connecting portion in the second direction. In other words, another connecting portion may be located between the second connecting portion and the first connecting portion in the second direction.

[0085] In the above embodiment, the circumferential positioning portion 4 is a recess. However, the circumferential positioning portion does not have to be a recess. The circumferential positioning portion may have a configuration that allows it to position the laminated core in the circumferential direction.

[0086] In the above embodiment, one side end 2a of the core piece 2 is formed by the second cutting step in the manufacturing method of the laminated core 1, and the other side end 2b of the core piece 2 is formed by the first cutting step in the manufacturing method of the laminated core 1. That is, in the above embodiment, the one side end 2a is the winding start end 81a of the core piece forming member 81, and the other side end 2b is the winding end end 81b of the core piece forming member 81. However, one side end of the core piece may be formed by the first cutting step in the manufacturing method of the laminated core, and the other side end of the core piece may be formed by the second cutting step in the manufacturing method of the laminated core. That is, the one side end may be the winding end end of the core piece forming member, and the other side end may be the winding start end of the core piece forming member.

[0087] In the lamination process of the above embodiment, the core piece forming member 81 is wound around the outer peripheral surface of the winding jig T1. However, in the lamination process, the winding jig, which rotates together with the core piece forming member, may be rotated in the direction opposite to the winding direction W to wind the core piece forming member around the outer peripheral surface of the winding jig.

[0088] (Configuration example) The present technology can also be configured as follows.

[0089] (1) A method for manufacturing a laminated core is a method for manufacturing a laminated core in which a core piece forming member extending in a strip shape in one direction is deformed to one side in the width direction and wound spirally to produce a cylindrical laminated core extending in the axial direction. The manufacturing method of a laminated core includes a punching process in which the core piece forming member having a plate-shaped back yoke portion extending in one direction and a plurality of tooth portions extending from one side of the back yoke portion in the width direction to one side of the width direction is formed by punching out a plate-shaped steel plate; a stacking process in which the core piece forming member is deformed to one side in the width direction and wound spirally, and the back yoke portion and the tooth portions are stacked and stacked in the axial direction; a first cutting process in which the core piece forming member stacked in the axial direction is cut in the width direction at a position a first distance rearward in the winding direction from the winding start end of the core piece forming member when viewed in the axial direction, thereby forming a winding end on the core piece forming member; and a second cutting process in which the core piece forming member is cut in the width direction at a position overlapping the winding start end when viewed in the axial direction, thereby forming the winding start end of the core piece forming member to be wound spirally next.

[0090] (2) In the manufacturing method of a laminated core described in (1), in the first cutting process, the core piece forming member is cut in the width direction at a position rearward of the winding start end of the core piece forming member in the winding direction, and at a central angle of less than 180 degrees from the position of the winding start end when viewed in the axial direction.

[0091] (3) The manufacturing method of a laminated core according to (1) or (2), further comprising a joining step of joining, in the stacking direction, the back yoke portions of the core piece forming members stacked in the axial direction by the laminating step. In the punching step, a first recess is formed in an end portion on the other side in the width direction of the back yoke portion for the tooth portion closest to a position that will become the winding start end of the core piece forming member, and a second recess is formed in an end portion on the other side in the width direction of the back yoke portion for the tooth portion closest to a position that will become the winding end end of the core piece forming member. In the joining step, the back yoke portions of the core piece forming members stacked in the axial direction by the laminating step are joined in the stacking direction at the positions of the first recess and the second recess.

[0092] (4) The laminated core is a cylindrical laminated core extending in the axial direction, in which core pieces each having a plate-shaped back yoke portion extending in a spiral shape around a central axis and a plurality of teeth protruding radially inward from the back yoke portion are stacked in a state where the back yoke portion and the teeth portion overlap in the thickness direction. The core pieces have one side end portion formed by cutting at one end in the extension direction, and another side end portion formed by cutting at the other end in the extension direction. The laminated core has a portion where the number of laminated core pieces is one less between the one side end portion and the other side end portion in a direction opposite to a first direction from the one side end portion toward the other side end portion of the core piece as viewed in the axial direction.

[0093] (5) In the laminated core described in (1), the central angle of the portion where the number of laminated core segments is one less is less than 180 degrees.

[0094] (6) The laminated core according to (4) or (5) has a plurality of connecting portions that extend axially on radially outer end faces and connect the back yoke portions in the stacking direction. The plurality of connecting portions include a first connecting portion that is located on the radially outer end face of the tooth portion that is closest to the one end of the core piece, and a second connecting portion that is located on the radially outer end face of the tooth portion that is closest to the other end of the core piece.

[0095] (7) The laminated core according to (6) has at least three of the connecting portions arranged in a circumferential direction of the laminated core, and the second connecting portion is adjacent to the first connecting portion in a direction opposite to the first direction.

[0096] (8) The motor includes a stator having a laminated core according to any one of (4) to (7) and a coil wound around the laminated core, and a rotor arranged radially inward relative to the stator. [Industrial Applicability]

[0097] The present invention is applicable to a manufacturing method of a laminated core obtained by punching out a strip-shaped electromagnetic steel sheet and having a back yoke portion extending linearly in the longitudinal direction of the electromagnetic steel sheet and a plurality of teeth extending in the width direction of the electromagnetic steel sheet. [Explanation of symbols]

[0098] 1 Laminated core 1a Part with one less layer 2 Core pieces 2a One end 2b Other end 3 Connecting part 3a 1st connection part 3b 2nd connection part 4 Circumferential positioning part 11 Back Yoke 12 Teeth 21 Back yoke 22, 22a, 22b Teeth 80 steel plate 81 Core piece forming member 81a Winding start end 81b End of winding 83 Recess 83a First recess 83b Second recess CT1: The first distance behind the winding direction CT2 Position where it overlaps with the winding start end L1 Distance between the start and end of winding T1 Winding jig T2 welding equipment R1: The area where the number of laminated core pieces is one less R2 core area P Central axis of laminated core Q Central axis of winding jig

Claims

1. A method for manufacturing a laminated core in which a core piece forming member extending in a strip shape in one direction is deformed to one side in the width direction and wound spirally to manufacture a cylindrical laminated core extending in an axial direction, a punching process for punching a plate-shaped steel plate to form the core piece forming member, the core piece forming member having a plate-shaped back yoke portion extending in one direction and a plurality of teeth portions extending from one side of the back yoke portion in the width direction to one side in the width direction; a lamination process in which the core piece forming member is deformed to one side in the width direction and wound in a spiral shape, and the back yoke portion and the teeth portion are stacked in the axial direction; a first cutting step of cutting the core piece forming members stacked in the axial direction at a position a first distance behind the winding start end of the core piece forming members in the winding direction, when viewed in the axial direction, to form a winding end end on the core piece forming members; a second cutting step of cutting the core piece forming member in the width direction at a position overlapping the winding start end when viewed in the axial direction, thereby forming the winding start end of the core piece forming member to be wound spirally next; having Manufacturing method of laminated core.

2. 2. The method for manufacturing a laminated core according to claim 1, In the first cutting step, the core piece forming member is cut in the width direction at a position rearward in the winding direction with respect to the winding start end of the core piece forming member, the position being spaced apart by a central angle of less than 180 degrees from the position of the winding start end as viewed in the axial direction. Manufacturing method of laminated core.

3. 3. The method for manufacturing a laminated core according to claim 1 or 2, a joining step of joining the back yoke portions of the core piece forming members stacked in the axial direction in the stacking step in a stacking direction, In the punching step, a first recess is formed at an end portion of the back yoke portion on the other side in the width direction with respect to the tooth portion closest to a position that becomes the winding start end portion of the core piece forming member; a second recess is formed at an end portion of the back yoke portion on the other side in the width direction with respect to the tooth portion closest to the position that becomes the winding end portion of the core piece forming member; In the joining step, the back yoke portions of the core piece forming members stacked in the axial direction in the stacking step are joined in the stacking direction at the positions of the first recesses and the second recesses. Manufacturing method of laminated core.

4. A cylindrical laminated core extending in the axial direction, in which core pieces each having a plate-shaped back yoke portion extending in a spiral shape around a central axis and a plurality of teeth portions protruding radially inward from the back yoke portion are laminated in a state in which the back yoke portion and the teeth portions overlap each other in the thickness direction, the core piece has one side end portion formed by cutting at one end portion in the extension direction, and another side end portion formed by cutting at the other end portion in the extension direction, the laminated core has a portion between the one side end and the other side end in a direction opposite to a first direction from the one side end toward the other side end of the core piece as viewed in the axial direction, where the number of laminated core pieces is one less, Laminated iron core.

5. 2. The laminated core according to claim 1, The central angle of the portion where the number of laminated core pieces is one less is less than 180 degrees. Laminated iron core.

6. The laminated core according to claim 4, a plurality of connecting portions extending in the axial direction on radially outer end surfaces and connecting the back yoke portions in the stacking direction; The plurality of connecting portions are a first coupling portion located on an end surface of the core piece that is radially outward from the tooth portion that is closest to the one side end portion; a second coupling portion located on an end surface of the core piece that is radially outward from the tooth portion that is closest to the other end portion; Including, Laminated iron core.

7. 7. The laminated core according to claim 6, The laminated core has at least three of the connecting portions arranged in a circumferential direction thereof, The second connecting portion is adjacent to the first connecting portion in a direction opposite to the first direction. Laminated iron core.

8. A laminated core according to any one of claims 4 to 7; a stator having a coil wound around the laminated core; a rotor disposed radially inward relative to the stator; A motor having

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