MANUFACTURE OF LAYER-BUILT POLE CORE FOR STATOR

PROBLEM TO BE SOLVED: To provide the method of manufacturing a layer-built pole core for a stator, wherein a linked pole core member which is the intermediate state of pole core pieces and made by using a low cost cold rolled thin sheet for layer-building is partially heated to improve the workability of a heat treatment. SOLUTION: A shape-forming process, in which a linked pole core member 16 having annular linking parts 15a linking tips of respective pole teeth 14 of pole core pieces 26 is manufactured from stripe sheet material 10, a partial heat treatment process in which the linked pole core member 16 is conveyed intermittently into a heat treatment furnace, and the magnetic characteristic of a portion around slots, including the pole teeth 14, are improved by high-frequency induction heating coils 17 and 18 which are provided on the surface and rear sides of the member 16 at positions corresponding to a plurality of the pole teeth 14 arranged in a circle. A separation process in which the tip parts of the respective pole teeth 14 are separated and the annular linking parts 15a are removed, a layer-building process in which the outline shapes of the pole core pieces 26 are formed by punching, and a required number of the punched core pieces 26 are piled up successively are provided.