INSERT RING OF PISTON HAVING PISTON STRUCTURE WHEREIN PLURAL RING GROOVES FOR MOUNTING OIL RING AND COMPRESSION RING ARE FORMED TO UPPER PART OF PISTON

摘要

PURPOSE: An insert ring of a piston is provided to prevent lowering of the mechanical strength of the piston by improving the method of increasing the volume of a second land part of the piston. CONSTITUTION: An insert ring(30) of a piston has piston structure in which plural ring grooves for mounting an oil ring and a compression ring are formed to the upper part of the piston. The insert ring is mounted to the lower side of a top land of the piston. A top ring groove(32) for mounting a top ring and a volume-up groove(34) for volume-up are formed to the insert ring. The top surface of the insert ring is formed in a level shape and the bottom surface is inclined in a direction of inclining from the inside toward the outside.