To prevent the breakage of an insert mold at the conventional pouring time of wax and time of a wax discharge by hollowing the circumference of the insert mold over the whole manufacturing process of a mold using the insert mold.
The manufacturing method of the mold firstly manufactures a metallic mold for forming a frame (S1) to form a hollow frame by this method (S2). Thereafter, at least a part of the insert mold preformed of a lost removable material is arranged in a hollow frame (S4) and a mold structural material is fixed on the outer surface (S5). The hollow frame can be formed by integrating resin or paper-made member or assembling plural members, and in the case of resin-made, the lost-removal is executed with the following burning process (S6). Desirably, a hole part for air venting is formed in the hollow frame and a supporting structure of the insert mold is preformed in the inner wall of the hollow frame. As the manufacturing method of a precision casting, after executing the casting by using this mold (S7), the insert mold is lost- removed (S9).
KUTARAGI YOSHIKAZU
WAKITA SABURO
