| 摘要 |
PROBLEM TO BE SOLVED: To reduce oil consumption while forming an appropriate oil film.SOLUTION: An oil ring 100 comprises: side rails 20, 20; and a spacer expander 30. A slide surface 25 of a first side rail 20A on the combustion chamber S1 side includes: a first curve surface 26 located on the combustion chamber S1 side of an apex p; and a second curve surface 27 located on the crank case S2 side of the apex P. In a cross-sectional shape orthogonal to a circumferential direction, the first curve surface 26 and the second curve surface 27 are connected together at the apex P such that tangents t1 and t2 of their respective cross-sectional shapes coincide with each other. In the cross-sectional shapes of the first curve surface 26 and the second curve surface 27, when comparing the rates of change in deviation inward in the radial direction relative to the distance in the axial direction from the apex P at the point of the same distance in the axial direction from the apex P, the rate of change of the first curve surface 26 is smaller than the rate of change of the second curve surface 27.SELECTED DRAWING: Figure 1 |
