Patent ID: 11754017

Abstract:
A piston of an internal combustion engine configured to be reciprocable along an axial direction in a cylinder includes a cavity formed to be recessed in a center of a piston top surface, and an outer circumferential edge portion located on a radially outer side of the cavity in the piston top surface. The cavity includes a lip portion, a raised portion, and a curved portion. The curved portion includes an outer circumference-side curved surface which includes a curved surface connected to the lip portion, an inner circumference-side concave surface which is located on a radially inner side of an outer circumference-side curved surface and includes a surface connected to a raised portion, the inner circumference-side concave surface including a deepest portion of the cavity, and a convex surface formed between the outer circumference-side curved surface and the inner circumference-side concave surface, as well as protruding upward.