GEAR MOLD AND GEAR MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a gear mold capable of enhancing the precision of a tooth shape even if there is an undercut part. SOLUTION: The gear mold 5 is used for molding a gear 1 comprising a worm wheel containing an annular tooth bed 4 made of a resin wherein a large number of teeth 3 are arranged in an annular form. A cavity for molding the annular tooth body 4 is formed by combining a fixed mold 50 having a first part 6 and a second part 7 with a movable mold 8. A protruded tooth shape molding surface 10 for forming the recessed tooth shape surface 3a being the substantial tooth shape of the gear is formed to the inner peripheral surface 3a of the hole 9 of the first part 6 of the fixed mold 50. At least the tooth shape molding surface 10 is formed by the surface of an electroforming layer. The surface hardness of the electroforming layer is set to a range of HRC 40-70 as Rockwell hardness. COPYRIGHT: (C)2006,JPO&NCIPI