JPS6478667A - Production of mechanical parts - Google Patents

Abstract

PURPOSE:To enable the aversion of the hot crack of a mechanical cast stock and the damage of a die and the shape setting by a small-size setting device by specifying the timing for parting of the mechanical stock cast in the die and the shape setting thereof. CONSTITUTION:A molten metal is poured into the die 1 heated by a heating circuit 8 at the time of casting a cam shaft stock 2 by using, for example, a die casting device M1 equipped with the die 1. The heating by the circuit 8 is stopped after the start of pouring and the cooling of the die 1 is started by a cooling circuit 9. The surface layer of the stock 2 is rapidly cooled by this cooling. Parting from the die is executed when the surface layer changes to a shell-like solidified layer. The formation of the hot crack in the stock 2 is thereby obviated and since the stock is covered in the shell-like solidified layer, the deformation at the time of parting is suppressed. In addition, the damage of the die 1 is not generated. The stock 2 in the high-temp. state right after the parting is subjected to a pressurization treatment by a setting device 25 and is thereby set in the shape. Since the stock 2 is easily plastically deformed at a high temp. at this time, the sure shape setting is executed under the relatively small pressurization force.