| 摘要 |
PURPOSE:To improve the heat resisting impact characteristic of a piston ever so high, by decreasing a volumetric ratio in a high tensile strength fiber, constituting a thermal strut, gradually from a radial inner side part toward a radial outer side part of the thermal strut. CONSTITUTION:A piston 10 is made up of casting a light alloy in high pressure. A thermal strut 32 is cast in a skirt shoulder part 30 by means of internal chill casting. Yarn 34 is wound up so as to decrease bulk density in a high tensile strength fiber from an inner circumferential part to an other circumferential part of the thermal strut 32. With high-pressure injection of molten metal of a light metal base material, this molten metal is impregnated in space between fibers, and the base material is closely bonded on a fiber surface. Thus, the heat resisting impact characteristic of the piston is well improved so that any crack is preventable from occurring. |
