Manufacturing method of core for rotary electric machine

1. A manufacturing method of a core for a rotary electric machine, said core includes a rotor core and a stator core, the method comprising the steps of:

forming the rotor core by stacking a plurality of rotor plate members each having a hole portion, and

forming the stator core by stacking a plurality of stator plate members each having a slot portion;

forming a stator side release hole in at least a first portion of a portion of an electric steel plate in which the slot portion is formed;

forming a rotor side hole portion in at least a part of a portion of the electric steel plate in which the hole portion is formed;

forming a flattened portion between the stator side release hole and the rotor side hole portion, by decreasing a thickness of a portion of the electric steel plate that becomes a part of an outer periphery of the rotor core in a radial direction, after the forming the stator side release hole and the forming the rotor side hole portion; and

forming the rotor plate member and the stator plate member by blanking the electric steel plate, after the forming the flattened portion.

2. The manufacturing method of a core for a rotary electric machine according to claim 1 , wherein the forming the stator side release hole comprises integrally blanking the first portion and a connecting portion between a portion in which the flattened portion is formed and a portion in which the slot portion is formed.

3. The manufacturing method of a core for a rotary electric machine according to claim 2 , wherein the forming the stator side release hole comprises integrally blanking the connecting portion and the first portion so that the connecting portion and the first portion have at least one shape of a U shape, an L shape, or an I shape when viewed in plan.

4. The manufacturing method of a core for a rotary electric machine according to claim 3 , wherein the forming the stator side release hole comprises integrally blanking the connecting portion and the first portion while a width of the first portion in a circumferential direction is larger than a width of the connecting portion in the radial direction.

5. The manufacturing method of a core for a rotary electric machine according to claim 4 , wherein the forming the stator side release hole comprises forming the stator side release hole so that the width of the connecting portion in the radial direction is equal to or more than 0.4 mm and equal to or less than 0.8 mm.

6. The manufacturing method of a core for a rotary electric machine according to claim 3 , wherein the forming the stator side release hole comprises forming the stator side release hole so that the width of the connecting portion in the radial direction is equal to or more than 0.4 mm and equal to or less than 0.8 mm.

7. The manufacturing method of a core for a rotary electric machine according to claim 3 , wherein the manufacturing method further comprises blanking a second portion after the forming the stator side release hole and before the forming the rotor plate member, the second portion including the stator side release hole and being at least a part of a portion of the electric steel plate in which the slot portion is formed.

8. The manufacturing method of a core for a rotary electric machine according to claim 7 , wherein the blanking the second portion comprises integrally blanking the second portion that is at least a part of a portion in which a plurality of the slot portions are formed.

9. The manufacturing method of a core for a rotary electric machine according to claim 2 , wherein the forming the stator side release hole comprises forming the stator side release hole so that the width of the connecting portion in the radial direction is equal to or more than 0.4 mm and equal to or less than 0.8 mm.

10. The manufacturing method of a core for a rotary electric machine according to claim 9 , wherein the forming the stator side release hole comprises forming the stator side release hole so that the width of the connecting portion in the radial direction is equal to or more than 0.4 mm and equal to or less than 0.7 mm.

11. The manufacturing method of a core for a rotary electric machine according to claim 2 , wherein the manufacturing method further comprises blanking a second portion after the forming the stator side release hole and before the forming the rotor plate member, the second portion including the stator side release hole and being at least a part of a portion of the electric steel plate in which the slot portion is formed.

12. The manufacturing method of a core for a rotary electric machine according to claim 11 , wherein the blanking the second portion comprises integrally blanking the second portion that is at least a part of a portion in which a plurality of the slot portions are formed.

13. The manufacturing method of a core for a rotary electric machine according to claim 1 , wherein the forming the stator side release hole comprises forming the stator side release hole in the first portion having a width in the circumferential direction that is smaller than the width of the slot portion in the circumferential direction.

14. The manufacturing method of a core for a rotary electric machine according to claim 1 , wherein the manufacturing method further comprises blanking a second portion after the forming the stator side release hole and before the forming the rotor plate member, the second portion including the stator side release hole and being at least a part of a portion of the electric steel plate in which the slot portion is formed.

15. The manufacturing method of a core for a rotary electric machine according to claim 14 , wherein the blanking the second portion comprises integrally blanking the second portion that is at least a part of a portion in which a plurality of the slot portions are formed.

16. The manufacturing method of a core for a rotary electric machine according to claim 15 , wherein the forming the rotor plate member and the stator plate member comprises blanking the stator plate member from the electric steel plate after blanking the rotor plate member from the electric steel plate by cutting off a portion, which is different from the stator side release hole and the second portion, of the electric steel plate which becomes the outer periphery of the rotor core, after the blanking the second portion.

17. The manufacturing method of a core for a rotary electric machine according to claim 16 , wherein the forming the rotor plate member and the stator plate member comprises blanking the stator plate member from the electric steel plate after forming the slot portion by integrally blanking the slot portions and a portion from which the portion that becomes the outer periphery of the rotor core is cut off, after the blanking the rotor plate member from the electric steel plate.

18. The manufacturing method of a core for a rotary electric machine according to claim 14 , wherein the forming the rotor plate member and the stator plate member comprises blanking the stator plate member from the electric steel plate after blanking the rotor plate member from the electric steel plate by cutting off a portion, which is different from the stator side release hole and the second portion, of the electric steel plate which becomes the outer periphery of the rotor core, after the blanking the second portion.

19. The manufacturing method of a core for a rotary electric machine according to claim 18 , wherein the forming the rotor plate member and the stator plate member comprises blanking the stator plate member from the electric steel plate after forming the slot portion by integrally blanking the slot portions and a portion from which the portion that becomes the outer periphery of the rotor core is cut off, after the blanking the rotor plate member from the electric steel plate.

20. The manufacturing method of a core for a rotary electric machine according to claim 1 , wherein the forming the rotor side hole portion is a step of forming a rotor side release hole portion in a part of a portion of the electric steel plate in which the hole portion is formed.