Patent ID: 7306233
Filing Date: 2007-12-11
Classification: F16J

Abstract:
1. A combined oil control ring consisting of: an oil ring body which is integrally formed of upper and lower rails which bring outer peripheral surfaces thereof into slide contact with an inner surface of a cylinder and a web which connects said upper and lower rails and includes a plurality of windows, and a coil expander which pushes said oil ring body in the direction toward said inner surface of said cylinder, said coil expander being housed in an inner-peripheral groove portion of said oil ring body, wherein projecting portions which extend toward a center line in the thickness direction are formed at inner peripheral sides in the radial direction than a position where an axial distance between inner peripheries of said inner-peripheral groove portion of said oil ring body becomes maximum, wherein the axial distance between inner-peripheries of said inner-peripheral groove portion of the oil ring body is smaller than a maximum distance L and wherein a minimum distance L