PURPOSE: To precisely form a fine spaped part in a casting by fitting a forming parts composed of a non-foaming material at the necessary position of a consumable pattern body.
CONSTITUTION: At the same time of forming the lost foam pattern body 12, a prepared hole 12a is preformed. In this prepared hole 12a, the pre-formd parts 15 composed of the non-foaming material of a synthetic resin having consumability is inserted and fitted. In the inner surface of the formed parts 15, a screw hole parts 13b and a screw thread 13c are precisely formed. At the time of casting, as a cavity shape in a mold is formed along the outer shapes of the lost foam pattern body 12 and the forming part 13, the shape of the mold having the screw hole parts is precisely formed according to the precise outer shape of the forming parts 13.
YAMAMOTO SUKEHIRO
KITAHARA KAZUNOBU
