| 摘要 |
PURPOSE:To decrease defective products and to reduce cost by holding a partially reinforcing inorg. fiber assemblage or porous metallic molding by a meltable core held by the post of a pressurizing punch thereby decreasing a piston-reinforcing member to a min. required amt. without damaging said member. CONSTITUTION:A meltable cooling chamber core 4 made of a salt, etc. is held by the boss 3 of a post 2 of a pressurizing punch 1 and an inorg. fiber assemblage of ceramics or the like or a porous metallic molding which is brittle but is highly resistant to heat and wear is held by the core 4. The punch 1 is inserted into cylindrical metallic molds 7, 8 and a molten metal 9 for a piston member poured therein is cast under pressure. A piston reinforcing member 6 is kept free from undue stress hence failure is overted and is made into the shape of a min. required amt., by which the yield of the product is improved and the cost thereof is reduced. A cooling chamber 14 contacting with the member 6 is formed by the outflow of the core 4, by which the cooling effect is improved. |
