Abstract: Provided is a side rail 1 having an outer peripheral surface 14, an inner peripheral surface 13, a first axial side surface 11, and a second axial side surface 12 parallel to the first axial side surface 11, in which, a beveled portion 30 is provided between the outer peripheral surface 14 and the second axial side surface 12, the beveled portion 30 is formed in a tapered surface having a diameter gradually decreasing from the first axial side surface 11 toward the second axial side surface in an axial direction; a tapered surface 30a is provided between a first tapered surface portion 30a1 with an angle of 10° or more to the axial direction and a second tapered surface portion 30a2 provided between the first tapered surface portion 30a1 and the outer peripheral surface 14 and having a smaller angle of inclination to the axial direction than that of the first tapered surface portion.

Abstract: An oil control ring according the present disclosure includes a pair of side rails, and a spacer expander disposed between the pair of side rails. The spacer expander includes a plurality of sets and each set includes a lug part and a rail facing part. For each set, the lug part is in contact with an inner circumferential surface of either of the pair of the side rails, and the rail facing part is provided adjacent to the lug part and faces a side surface of either of the pair of the side rails. The lug part satisfies a following condition (1): W/H?1.5??(1) In condition (1), W indicates a width of the lug part at a position 0.05 mm away from a highest position of the lug part in a direction towards the rail facing part, and H indicates a height difference between a highest position of a region on the rail facing part adjacent to the lug part and the highest position of the lug part.

Abstract: An oil control ring according the present disclosure includes a pair of side rails, and a spacer expander disposed between the pair of side rails. The spacer expander includes a plurality of sets and each set includes a lug part and a rail facing part. For each set, the lug part is in contact with an inner circumferential surface of either of the pair of the side rails, and the rail facing part is provided adjacent to the lug part and faces a side surface of either of the pair of the side rails. The lug part satisfies a following condition (1): W/H?1.5 ??(1) In condition (1), W indicates a width of the lug part at a position 0.05 mm away from a highest position of the lug part in a direction towards the rail facing part, and H indicates a height difference between a highest position of a region on the rail facing part adjacent to the lug part and the highest position of the lug part.

Abstract: Provided is a side rail 1 having an outer peripheral surface 14, an inner peripheral surface 13, a first axial side surface 11, and a second axial side surface 12 parallel to the first axial side surface 11, in which, a beveled portion 30 is provided between the outer peripheral surface 14 and the second axial side surface 12, the beveled portion 30 is formed in a tapered surface having a diameter gradually decreasing from the first axial side surface 11 toward the second axial side surface in an axial direction; a tapered surface 30a is provided between a first tapered surface portion 30a1 with an angle of 10° or more to the axial direction and a second tapered surface portion 30a2 provided between the first tapered surface portion 30a1 and the outer peripheral surface 14 and having a smaller angle of inclination to the axial direction than that of the first tapered surface portion.

Abstract: A side rail (1) is formed in a sprit ring shape with an opening (10) and to be mounted on a space expander (2) in an annular shape to constitute, together with the space expander (2), a multi-piece oil ring (3) used in an internal combustion engine. The side rail (1) includes an outer peripheral surface (14) facing radially outward, an inner peripheral surface (13) facing radially inward, a first axial surface (11) facing a crankcase, a second axial surface (12) facing a combustion chamber and parallel to the first axial surface (11), and a protrusion (20) formed on the outer peripheral surface (14) in a position offset from an intermediate position between the first axial surface (11) and the second axial surface (12) toward the first axial surface (11) and protruding radially outward from the outer peripheral surface (14).

Abstract: A side rail (1) is formed in a sprit ring shape with an opening (10) and to be mounted on a space expander (2) in an annular shape to constitute, together with the space expander (2), a multi-piece oil ring (3) used in an internal combustion engine. The side rail (1) includes an outer peripheral surface (14) facing radially outward, an inner peripheral surface (13) facing radially inward, a first axial surface (11) facing a crankcase, a second axial surface (12) facing a combustion chamber and parallel to the first axial surface (11), and a protrusion (20) formed on the outer peripheral surface (14) in a position offset from an intermediate position between the first axial surface (11) and the second axial surface (12) toward the first axial surface (11) and protruding radially outward from the outer peripheral surface (14).