Steel plate punching die and method for manufacturing rotating electric machine

Abstract

To provide a steel sheet punching metal die allowed to improve maintainability, and a method of manufacturing a rotary electric machine.SOLUTION: A steel sheet punching metal die 10 comprises: a die 11 for forming an outer shape of a sheet-formed member 22; a punch 12 for punching the sheet-formed member 22 out of a steel sheet K; and a stripper 13 having a vertically penetrating guide hole 13H having the same shape as the sheet-formed member 22 and for clamping the steel sheet K with the die 11. At least one of the die 11 and the stripper 13 includes grooves 11b, 13b formed along an edge closer to the punch 12 on a surface to contact the steel sheet K when shearing the sheet-formed member 22.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present application relates to a steel plate punching die and a method for manufacturing a rotating electric machine. [Background technology]

[0002] Conventionally, motor cores are known that are constructed by stacking core pieces punched out by a steel plate punching die. The steel plate punching die is equipped with a stripper to suppress slippage when punching the steel plate, and the stripper is formed with a V-shaped protrusion to improve the punching dimensions and the accuracy of the sheared surface of the steel plate (for example, see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-1449 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional die structures with V-shaped protrusions, it is difficult to maintain and manage the V-shaped protrusions. In other words, there is an issue that large stress is concentrated on the V-shaped protrusions, and the tips quickly wear out, reducing the gripping force of the steel plate, which leads to a deterioration in the accuracy of the shear surface of the steel plate. In addition, when maintaining the die, it is common to polish the contact surface of the stripper that comes into contact with the steel plate, but after polishing in a way that avoids the V-shaped protrusions, it is necessary to separately process the V-shaped protrusions, which is a time-consuming task.

[0005] The present application discloses technology for solving the problems described above, and aims to provide a steel plate punching die and a manufacturing method for a rotating electric machine that are highly durable, enable improvement in the precision of the shear surface of the steel plate, and can improve maintainability. [Means for solving the problem]

[0006] The steel plate punching die disclosed in the present application comprises: A die for forming the outer shape of the plate-like member; A punch for punching the plate-shaped member out of a steel plate; A plate-shaped member having the same shape as the plate-shaped member and penetrating in the vertical direction And the punch passes through a stripper having a guide hole and sandwiching the steel sheet between the stripper and the die, before The above stripper ,before The edge of the surface that contacts the steel plate when the plate-like member is sheared is on the punch side. 、 and an edge of the punch on the stripper side of a surface that contacts the steel plate when the plate-like member is sheared; A groove is formed along at least one edge of the It is something. In addition, the steel plate punching die disclosed in the present application is A die for forming the outer shape of the plate-like member; A punch for punching the plate-shaped member out of a steel plate; a stripper having a guide hole that penetrates in the vertical direction and has the same shape as the plate-like member and through which the punch passes, and sandwiches the steel plate between the stripper and the die; a groove portion is formed along an edge of the punch side of a surface of the stripper that contacts the steel plate when the plate-like member is sheared; The punch passes through the guide hole without passing through the groove portion formed in the stripper, thereby punching out the plate-like member from the steel plate. Effect of the Invention

[0007] The steel plate punching die and the manufacturing method for a rotating electric machine disclosed in the present application can provide a steel plate punching die and a manufacturing method for a rotating electric machine that are highly durable, can improve the accuracy of the shear surface of the steel plate, and can improve maintainability. [Brief description of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. [Diagram 2] 1 is a perspective view of a stator core according to a first embodiment. [Diagram 3] FIG. 2 is a perspective view of a split core according to the first embodiment. [Figure 4] 3 is a plan view of a core piece punched out by the steel plate punching die according to the first embodiment. FIG. [Diagram 5] FIG. 1 is a perspective view of a steel plate punching die according to a first embodiment. [Figure 6]FIG. 2 is a perspective view of a die of the steel plate punching metal mold according to the first embodiment. [Figure 7] 7 is an enlarged cross-sectional view of a main part taken along line AA in FIG. 6. [Figure 8] FIG. 2 is a perspective view of a punch of the steel plate punching die according to the first embodiment. [Figure 9] 9 is an enlarged cross-sectional view of a main part taken along line BB in FIG. 8. [Figure 10] FIG. 2 is a perspective view of a stripper of the steel plate punching die according to the first embodiment. [Figure 11] 11 is an enlarged cross-sectional view of a main portion taken along line CC in FIG. 10. [Figure 12] 1 is an enlarged cross-sectional view of a main portion showing a state immediately before the steel plate is punched by the steel plate punching die according to embodiment 1. FIG. [Figure 13] 2 is an enlarged cross-sectional view of a main portion showing a state immediately after punching a steel plate by the steel plate punching die according to embodiment 1. FIG. [Figure 14] 2 is an enlarged cross-sectional view of a main portion showing a state immediately after punching a steel plate by the steel plate punching die according to embodiment 1. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Embodiment 1 Hereinafter, the method for manufacturing the steel plate punching die and the rotating electric machine according to the first embodiment will be described with reference to the drawings. In the following drawings, the size relationships of the components may differ from the actual ones. Also, the same reference numerals denote the same members or equivalents. In addition, in this specification, when referring to a top-bottom relationship, the upper side (upper side of the paper) of the steel plate punching die 10 shown in Fig. 5 is referred to as "upper" and the lower side is referred to as "lower". In addition, when referring to the "inside" and "outside" of the die, punch, and stripper, the part in question is used as the boundary, and the side where the center of each member exists is referred to as the inside, and the opposite side is referred to as the outside.

[0010] FIG. 1 is a cross-sectional view of a rotating electric machine 100. FIG. 2 is a perspective view of the stator core 20. As shown in FIG. FIG. 3 is a perspective view of the split core 21. As shown in FIG. FIG. 4 is a plan view of the core piece 22. As shown in FIG. FIG. 5 is a perspective view of the steel plate punching die 10. As shown in FIG.

[0011] The rotating electric machine 100 comprises a stator 2 fixed inside a housing 1, and a rotor 3 rotatably supported via a gap, with its outer circumferential surface facing the inner circumferential surface of the stator 2. The stator 2 comprises an annular stator core 20 and coils 4 wound around each tooth of the stator core 20. The rotor 3 also comprises a rotor core 3a and a shaft 3b inserted in the axial direction Z and fixed to the center of the rotor core 3a.

[0012] The stator core 20 shown in Fig. 2 is configured by combining and arranging a plurality of split cores 21 shown in Fig. 3 in an annular shape. The split core 21 is formed by stacking and fixing a plurality of core pieces 22 (plate-shaped members) shown in Fig. 4 punched out by a steel plate punching die 10 in the axial direction Z. The core pieces 22 are configured with a back yoke portion 22a extending in the circumferential direction X, and teeth portions 22b protruding inward in the radial direction Y from the center of the inner side in the radial direction Y of the back yoke portion 22a.

[0013] In order to reduce iron loss due to eddy currents, the split cores 21 that make up the stator core 20 are generally constructed by laminating core pieces 22. Furthermore, thin steel sheets of about 0.1 mm to 1 mm are often used as the core pieces 22 to suppress iron loss due to eddy currents, and electromagnetic steel sheets are often used to improve magnetic properties.

[0014] Incidentally, a large number of core pieces 22 are required to construct the stator core 20. For this reason, a production method using a steel plate punching die and a high-speed press machine, which are excellent in mass production of the same parts, has been conventionally used. Note that in the present embodiment 1, the stator core 20 is formed by arranging a plurality of split cores 21, each of which is formed by stacking the core pieces 22, in a circular shape. However, the stator core may be formed by stacking a plurality of core pieces punched in a circular shape in the axial direction Z without dividing the core pieces in the circumferential direction X.

[0015] The steel plate punching die 10 shown in FIG. 5 includes a die 11 that forms the outer shape of a core piece 22, a punch 12 that punches the core piece 22 out of the steel plate, and a stripper 13 that clamps the steel plate between the die 11 and the punch 12.

[0016] FIG. 6 is a perspective view of the die 11 of the steel plate punching die 10. As shown in FIG. FIG. 7 is an enlarged cross-sectional view of a main portion taken along line AA in FIG. The die 11 has a die shear processing portion 11a for shearing the steel sheet on the upper surface, and the die shear processing portion 11a has the same shape as the core piece 22. When the steel sheet is sheared, the upper surface comes into contact with the steel sheet. Below the die shear processing portion 11a, a through hole 11H having the same shape is formed penetrating through the die 11. The die shear processing portion 11a is formed on the inner peripheral edge (the edge on the punch 12 side described later) of the upper surface of the die 11. In addition, on the upper surface of the die 11, on the outer side of the die shear processing portion 11a, a die groove portion 11b is formed along the die shear processing portion 11a.

[0017] The inner portion 11c of the die groove 11b on the upper surface of the die 11 and the outer portion 11d of the die groove 11b on the upper surface of the die 11 exist in the same imaginary plane. That is, the inner portion 11c is also included in the imaginary plane including the outer portion 11d. The shape of the die groove 11b shown in FIG. 7 is an arc shape in a cross section perpendicular to the longitudinal direction of the die groove 11b, but this is an example and is not limiting. It may be a square groove shape, a V groove shape, or any other special shape.

[0018] FIG. 8 is a perspective view of the punch 12 of the steel plate punching die 10. As shown in FIG. FIG. 9 is an enlarged cross-sectional view of a main portion taken along line BB in FIG. The punch 12 shown in FIG. 8 is the punch 12 shown in FIG. 5 turned upside down. Therefore, in FIG. 8, the bottom surface of the punch 12 shown in FIG. 5 is visible. The shape of the punch 12 seen from above is the same as that of the core piece 22. The punch 12 has a punch shear processing portion 12a on its bottom surface, which shears the steel plate together with the die shear processing portion 11a of the die 11, and has the same shape as the core piece 22. When the steel plate is sheared, the bottom surface comes into contact with the steel plate. The punch shear processing portion 12a is formed on the outer peripheral edge (the edge on the stripper 13 side) of the bottom surface of the punch 12. In addition, on the bottom surface of the punch 12, on the inside of the punch shear processing portion 12a, a punch groove portion 12b is formed along the punch shear processing portion 12a.

[0019] An inner portion 12c of the punch groove 12b on the lower surface of the punch 12 and an outer portion 12d of the punch groove 12b on the lower surface of the punch 12 exist in the same imaginary plane. That is, the inner portion 12c is also included in the imaginary plane including the outer portion 12d. The shape of the punch groove 12b shown in FIG. 9 is an arc shape in cross section perpendicular to the longitudinal direction of the groove, but this is an example and is not limiting. It may be a square groove shape, a V groove shape, or any other special shape.

[0020] FIG. 10 is a perspective view of the stripper 13 of the steel plate punching die 10. As shown in FIG. FIG. 11 is an enlarged cross-sectional view of a main portion taken along line CC in FIG. The stripper 13 shown in Fig. 10 is obtained by turning the stripper 13 shown in Fig. 5 upside down. Therefore, in Fig. 10, the bottom surface of the stripper 13 shown in Fig. 5 is visible. The stripper 13 has a guide hole 13H that penetrates in the vertical direction and has the same shape as the core piece 22. In addition, a stripper groove portion 13b is formed along the edge 13a on the lower surface of the stripper 13, outside the edge 13a of the guide hole 13H. When the steel sheet is sheared, the lower surface comes into contact with the steel sheet.

[0021] An inner portion 13c of the stripper groove 13b on the lower surface of the stripper 13 and an outer portion 13d of the stripper groove 13b on the lower surface of the stripper 13 exist in the same imaginary plane. That is, the inner portion 13c is also included in the imaginary plane including the outer portion 13d. The shape of the stripper groove 13b shown in FIG. 11 is an arc shape in cross section perpendicular to the longitudinal direction of the groove, but this is an example and is not limiting. It may be a square groove shape, a V groove shape, or any other special shape.

[0022] Next, the shearing of the core pieces 22 will be described. FIG. 12 is an enlarged cross-sectional view of a main portion showing a state immediately before the steel plate K is punched by the steel plate punching die 10. As shown in FIG. FIG. 13 is an enlarged cross-sectional view of a main portion showing the state immediately after the steel plate K is punched by the steel plate punching die 10. As shown in FIG. The steel sheet K is fixed by the die 11 and the stripper 13, and the punch 12 is lowered to punch the steel sheet K into the shape of the core piece 22. The core piece 22 is sheared by the die shear processing portion 11a of the die 11 and the punch shear processing portion 12a of the punch 12.

[0023] As described above, the die 11 has the die groove 11b on the outside of the die shear processing portion 11a. The punch 12 has the punch groove 12b on the inside of the punch shear processing portion 12a. The stripper 13 has the stripper groove 13b on the outside of the edge 13a of the guide hole 13H.

[0024] 13, when the steel sheet K is sheared, a stripper pressing load 50A is applied from above to the steel sheet K by the stripper 13. Since a stripper groove portion 13b is formed along an outer side of an edge 13a of the lower end of the guide hole 13H of the stripper 13, the load center of the stripper pressing load 50A is located between the edge 13a and the stripper groove portion 13b.

[0025] In the V-projection in the prior art document, in order to secure the strength of the die with which the V-projection contacts, one side of the V-projection needs to be separated by a considerable distance from the edge of the lower end of the guide hole. On the other hand, in the present embodiment, the steel sheet K can be reliably fixed at a position closer to the edge 13a of the guide hole 13H than the V-projection in the prior art, making it possible to improve the accuracy of the shear surface of the steel sheet K and at the same time suppress deformation due to warping of the steel sheet K.

[0026] At this time, a stripper reaction force 50B acts on the steel sheet K from below as a reaction force to the stripper pressing load 50A. Since a die groove portion 11b is formed along the die shear processing portion 11a on the outer side of the die shear processing portion 11a of the die 11, the load center of the stripper reaction force 50B is located between the die shear processing portion 11a and the die groove portion 11b.

[0027] Further, a shear load 51A of the punch 12 is applied from above to the steel sheet K. Since a punch groove portion 12b is formed along the punch shear processing portion 12a on the inner side of the punch shear processing portion 12a of the punch 12, the load center of the punch reaction force 51B is located between the die shear processing portion 11a and the die groove portion 11b.

[0028] In this way, when the steel plate K is sheared, the load center of the stripper pressing load 50A by the stripper 13 is located between the edge 13a and the stripper groove portion 13b, the load center of the stripper reaction force 50B is located between the die shear processing portion 11a and the die groove portion 11b, and the load center of the punch reaction force 51B is located between the die shear processing portion 11a and the die groove portion 11b. Therefore, since the steel plate K can be sufficiently fixed by clamping it from above and below at these locations, it is possible to improve the accuracy of the shear surface Kf of the steel plate K and also suppress deformation due to warping of the steel plate K.

[0029] Furthermore, when the steel plate K is sheared, the load center of the shear load 51A by the punch 12 is located between the punch groove portion 12b and the shear portion Ks of the steel plate K, and the load center of the punch reaction force 51B is located between the die groove portion 11b and the shear portion Ks of the steel plate K. Therefore, a shear load can be applied to the steel plate K at a position close to the shear portion Ks of the steel plate K, which makes it possible to improve the accuracy of the shear surface Kf of the steel plate K and also suppress deformation due to warping of the steel plate K.

[0030] In the steel plate punching die 10 according to embodiment 1, the die 11, punch 12 and stripper 13 are all provided with die groove portion 11b, punch groove portion 12b and stripper groove portion 13b, respectively. However, even if groove portions are provided in at least one of the die 11 and stripper 13, there is an effect of improving the accuracy of the shear surface Kf of the steel plate K and suppressing deformation due to warping of the steel plate K.

[0031] To manufacture the stator core 20, a large number of core pieces 22 are required. Therefore, it is necessary to punch out a large number of core pieces 22 using the steel plate punching die 10, and the contact surface between the steel plate punching die 10 and the steel plate K gradually wears out. Therefore, the contact surface of the steel plate punching die 10 with the steel plate K requires periodic maintenance by polishing.

[0032] In the steel plate punching die 10, the inner portion 11c of the die groove 11b on the upper surface of the die 11 and the outer portion 11d of the die groove 11b on the upper surface of the die 11 exist in the same imaginary plane as described above. Therefore, the inner portion 11c and the outer portion 11d can be polished simultaneously, and the steel plate punching die 10 is easy to maintain.

[0033] Similarly, inner portion 12c of punch groove 12b on the underside of punch 12 and outer portion 12d of punch groove 12b on the underside of punch 12 exist in the same imaginary plane. Therefore, inner portion 12c and outer portion 12d can be polished simultaneously, and maintenance is also easy.

[0034] Similarly, an inner portion 13c of the stripper groove portion 13b on the upper surface of the stripper 13 and an outer portion 13d of the stripper groove portion 13b on the upper surface of the stripper 13 exist in the same imaginary plane. Therefore, the inner portion 13c and the outer portion 13d can be polished simultaneously, and the maintenance is also excellent.

[0035] Furthermore, there are no specific restrictions on the width and depth of the die groove portion 11b, punch groove portion 12b, and stripper groove portion 13b. Therefore, even if the surfaces on which each groove is formed are polished for maintenance of the steel plate punching die 10 and the width and depth of the die groove portion 11b, punch groove portion 12b, and stripper groove portion 13b change slightly, there is no need to re-machine the die groove portion 11b, punch groove portion 12b, and stripper groove portion 13b themselves, and the die groove portion 11b, punch groove portion 12b, and stripper groove portion 13b can be used repeatedly simply by polishing the surfaces on which each groove is formed.

[0036] FIG. 14 is an enlarged cross-sectional view of a main portion showing a state immediately after the steel plate K is punched by the steel plate punching die 10B. In the steel plate punching die 10 described so far, the die 11, punch 12 and stripper 13 are each provided with a die groove portion 11b, a punch groove portion 12b and a stripper groove portion 13b, respectively. However, even if steps 11D, 12D and 13D are provided at the same positions instead of the respective groove portions, it is possible to improve the accuracy of the shear surface Kf of the steel plate K and also to suppress deformation due to warping of the steel plate K.

[0037] The steel plate punching die 10 and the manufacturing method for a rotating electric machine according to the first embodiment have high durability, can improve the accuracy of the sheared surface Kf of the steel plate K, can suppress warping of the steel plate K when punching the core pieces 22, and can improve the maintainability of the steel plate punching die 10. Furthermore, by providing the groove portion in at least one of the die 11 and the stripper 13, the steel plate K can be reliably held between the die 11 and the stripper 13 when the steel plate K is sheared.

[0038] The depth of the die groove portion 11b shown in FIG. 7 is also an example and is not restrictive. It is sufficient that the groove depth is equal to or greater than the thickness of the steel sheet K to be punched. The position of the die groove portion 11b is also an example and is not restrictive. The distance from the die shear processing portion 11a to the die groove portion 11b is only required to be 5 times the thickness of the steel sheet K to be punched. The width of the die groove portion 11b is also an example and is not restrictive. It is sufficient that the width of the die groove portion 11b is equal to or less than the thickness of the steel sheet K to be punched.

[0039] The depth of the punch groove portion 12b shown in FIG. 9 is also an example and is not restrictive. It is sufficient that the groove depth is equal to or greater than the thickness of the steel sheet K to be punched. The position of the punch groove portion 12b is also an example and is not restrictive. The distance from the punch shear processing portion 12a to the punch groove portion 12b is sufficient as long as it is five times or less the thickness of the steel sheet K to be punched. The width of the punch groove portion 12b is also an example and is not restrictive. It is sufficient that the width of the punch groove portion 12b is equal to or less than the thickness of the steel sheet K to be punched.

[0040] The depth of the stripper groove portion 13b shown in FIG. 11 is also an example and is not restrictive. It is sufficient that the groove depth is equal to or greater than the thickness of the steel sheet K to be punched. The position of the stripper groove portion 13b is also an example and is not restrictive. The distance from the edge 13a to the stripper groove portion 13b is not greater than five times the thickness of the steel sheet K to be punched. The width of the stripper groove portion 13b is also an example and is not restrictive. It is sufficient that the width of the stripper groove portion 13b is equal to or less than the thickness of the steel sheet K to be punched.

[0041] In the explanation so far, in the steel plate punching die 10, the die 11, punch 12, and stripper 13 are each configured as a single part, but the die 11, punch 12, and stripper 13 may be configured by assembling separate parts. Also, the die 11, punch 12, and stripper 13 may each be provided with a pin hole, guide post, and bolt hole to improve positioning accuracy.

[0042] Furthermore, a part such as a plate may be added to the steel plate punching die 10 in order to attach it to a punching press. Even if these modifications are made, by providing the die groove portion 11b, punch groove portion 12b, and stripper groove portion 13b according to the first embodiment, it is possible to improve the accuracy of the shear surface Kf of the steel plate K, and at the same time, it is possible to suppress deformation due to warping of the steel plate K. Furthermore, the steel plate punching die is excellent in terms of maintainability through polishing. Also, in this embodiment, an example has been described in which a core piece of a stator core is punched, but the same can be applied to a core piece of a rotor core.

[0043] Although exemplary embodiments are described herein, the various features, aspects, and functions described in the embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are expected within the scope of the technology disclosed in this application, including, for example, modifying, adding, or omitting at least one component. [Explanation of symbols]

[0044] 100 rotating electric machine, 1 housing, 2 stator, 20 stator core, 21 split core, 22 core piece, 22a back yoke portion, 22b teeth portion, 3 rotor, 3a rotor core, 3b shaft, 4 coil, 10, 10B steel plate punching die, 11 die, 11a die shear processing part, 11b die groove portion, 11c, 12c, 13 inner portion, 11d,12d,13d outer part, 11H through hole, 12 punch, 12a punch shear processing portion, 12b punch groove portion, 13 stripper, 13a edge, 13b stripper groove, 13H guide hole, Ks shear section, Kf shear surface, 50A Stripper pressure load, 50B Stripper reaction force, 51A Shear load, 51B punch reaction force, K steel plate, X circumferential direction, Y radial direction, Z axial direction.

Claims

1. A die for forming the outer shape of the plate-like member; A punch for punching the plate-shaped member out of a steel plate; a stripper having a guide hole that penetrates in the vertical direction and has the same shape as the plate-like member and through which the punch passes, and sandwiches the steel plate between the stripper and the die; an edge of the stripper on the punch side of a surface that contacts the steel plate when the plate-like member is sheared; and an edge of the punch on the stripper side of a surface that contacts the steel plate when the plate-like member is sheared; A steel plate punching die having a groove formed along at least one edge of the die.

2. 2. The steel plate punching die according to claim 1, wherein the die has a groove formed along an edge of the punch side of a surface that comes into contact with the steel plate when the plate-like member is sheared.

3. A die for forming the outer shape of a plate-shaped member; A punch for punching the plate-shaped member out of a steel plate; a stripper having a guide hole that penetrates in the vertical direction and has the same shape as the plate-like member and through which the punch passes, and sandwiches the steel plate between the stripper and the die; a groove portion is formed along an edge of the punch side of a surface of the stripper that contacts the steel plate when the plate-like member is sheared; The punch is a steel plate punching die that punches out the plate-shaped member from the steel plate by passing through the guide hole without passing through the groove portion formed in the stripper.

4. A manufacturing method for a rotating electric machine, comprising stacking the plate-shaped members punched using the steel plate punching die according to any one of claims 1 to 3 to form a stator core or a rotor core.

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