Combined oil ring
AssigneeTeikoku Piston Ring Co., Ltd.
InventorMasao Ishida
Life of this patent
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Abstract
In a three-piece combined oil ring comprising a pair of side rails and provided between them a spacer expander, the side rails are each provided in the inner edge thereof with a plurality of cutouts at given intervals, thereby providing a combined oil ring improved in its conformable property to any deformation of a cylinder bore. A nitrided layer is formed by plasma nitriding on each side rail only at its outer edge face, thereby preventing embrittlement of the side rails and improving the durability.
Claims4
In a three-piece combined oil ring comprising a pair of side rails and provided between them a spacer expander, the improvement wherein said side rails are each provided in the inner edge thereof with a plurality of cutouts at given intervals;
- and wherein said cutouts in the side rails are in a cutout pitch of from 2 to 4 mm, a cutout width of from 1 to 2 mm and a cutout depth of from 0.3 to 0.5 mm.
In a three-piece combined oil ring comprising a pair of side rails and provided between them a space expander, the improvement wherein said side rails are each provided in the inner edge thereof with a plurality of cutouts at given intervals, and a nitrided layer is formed by plasma nitriding on each of said side rails only at its outer edge face;
- and wherein said cutouts in the side rails are in a cutout pitch of from 2 to 4 mm, a cutout width of from 1 to 2 mm and a cutout depth of from 0.3 to 0.5 mm.
Dependencies are inferred from the claim text.