Piston for internal combustion engines

Abstract

A piston for internal combustion engines, capable of being manufactured easily and improving the durability of a combustion chamber, moved reciprocatingly in a cylinder of an internal combustion engine, and provided in a top surface thereof with a combustion chamber formed by recessing the same top surface, and in an outer circumferential wall of the combustion chamber with a cooling cavity the inner diameter of a lower portion of an inner circumferential surface of which is set smaller than that of an upper portion thereof, wherein a cross-sectionally angular portion defined by an upper edge portion, at which the combustion chamber is opened in the interior of a cylinder, of an inner circumferential surface of the combustion chamber and a piston-top surface is chamfered greatly in conformity with the cross-sectional shape of the upper portion of the inner circumferential surface of the cooling cavity to such an extent that the thickness of an upper portion of an inner circumferential wall of the cooling cavity does not greatly vary.

Dependencies are inferred from the claim text.