发明名称 |
PRODUCTION OF PISTONS HAVING A CAVITY |
摘要 |
A piston of a light alloy matrix material having a cavity for containing heat insulating air immediately below its head or a cavity for passing cooling oil inside the grooved side wall is manufactured by preforming a precursory member having the shape of the cavity from an extractable material which remains in solid state at room temperature and is convertible into a fluid, gas or liquid when heated at a temperature below the melting point of the matrix metal. The precursory member is disposed in place in a pressure casting mold having a cavity corresponding to the shape of the piston, and covered with a porous member stable to the molten matrix metal. A head member of heat resisting metal material to constitute at least a portion of the piston head may be disposed on the mold cavity bottom. Molten matrix metal is then cast into the mold cavity and a pressure is applied thereto to form a piston-shaped casting having precursory member and porous member embedded therein. Finally the casting is heated at a sufficient temperature to gasify or liquefy the extractable material of the precursory member material into fluid, which is extracted from the casting, leaving a cavity at the location of the precursory member. Alternatively, the precursory member may be formed from a composite material of a gasifiable material and a stable material whereby the cavity is given as a porous insert of the stable material which is left after the extraction of the gasifiable material by heating. |
申请公布号 |
EP0209090(A3) |
申请公布日期 |
1987.08.19 |
申请号 |
EP19860109510 |
申请日期 |
1986.07.11 |
申请人 |
TOYOTA JIDOSHA KABUSHIKI KAISHA |
发明人 |
HAMAJIMA, KANEO;DOHNOMOTO, TADASHI;TANAKA, ATSUO;KUBO, MASAHIRO |
分类号 |
B22D19/00;F02B3/06;F02F3/00;(IPC1-7):B22D19/00;B22C9/24 |
主分类号 |
B22D19/00 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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