To improve producibility by minimizing fraction defective of welding in laser beam welding of a laminated steel plate.
In this manufacturing method of a core, a number of steel plates which are formed of an electromagnetic material and shaped as specified are laminated and a plurality of places of a welding part are welded and formed by laser beam 10. In the method, the welded parts 22b, 22d are made a combined part 22z of a steel plate and a core is welded and formed by casting laser beam 10 of the same strength several times by using each combined parts 22z as irradiation points 22a, 22c of the laser beam 10. In the method, ail attaching to an edge part of a steel plate is evaporated and temporary welding is carried out by first welding, and regular welding is carried out after second welding and specified welding strength is obtained.
YAMADA TOYONOBU
OZAWA SHIGEO
