Patent ID: 6412171
Filing Date: 2002-07-02
Classification: F04B,Y10T

Abstract:
A method of producing a body member of a piston for a swash plate type compressor, said body member including a generally hollow cylindrical head section having a closed end and an open end which is closed by a closing member so as to provide a head portion of said piston, and an engaging section which is formed integrally with a bottom portion of said hollow cylindrical head section which is located at said closed end, said engaging section giving an engaging portion of said piston for engagement with a swash plate of the compressor, comprising the steps of:preparing a die-casting device including a casting mold consisting of: two mold halves which are spaced apart from each other and butted together in a direction perpendicular to a centerline of said hollow cylindrical head section, said two mold halves having respective molding surfaces; and a slide core which is slidably movable in a direction parallel to said centerline such that said slide core is advanced into and retracted from said casting mold, said slide core cooperating with said molding surfaces of said mold halves to define therebetween a mold cavity when said slide core is advanced into said casting mold, said mold cavity having a configuration following that of said body member which includes said hollow cylindrical head section and said engaging section, at least a front end portion of said slide core having a nonaxisymmetric configuration with respect to a centerline of said slide core; and die-casting said body member using said die-casting device, such that said hollow cylindrical head section has an inner bottom surface having a three-dimensional configuration which is nonaxisymmetric with respect to said centerline of said hollow cylindrical head section corresponding to said nonaxisymmetric configuration of said front end portion of said slide core.