Patent application title: Piston, Oil Regulating Ring for Piston, Manufacturing Method of Piston, and Manufacturing Method of Oil Regulating Ring for Piston

摘要

There is provided a piston for an internal combustion engine having an improved oil control ring. The piston has a piston body which provides an upper combustion surface and an annular outer wall extending downwardly from the upper combustion surface. A ring belt section including a plurality of ring grooves is formed in the annular outer wall. A first compression ring is disposed in one of the plurality of ring grooves and an oil control ring is disposed in the other of the plurality of ring grooves. The oil control ring has generally parallel, planar top and bottom surfaces, the top and bottom surfaces having an annular groove recessed. A through opening may be formed to fluidly communicate the annular groove with each other. The annular groove collects the scraped oil from the cylinder wall to return the oil to the crank sump and reduces the contact area between the oil control ring and the wall of the ring groove.