US 12,292,118 B2
Piston ring
Yushi Abe, Tokyo (JP); Naoki Umeda, Tokyo (JP); Masayuki Ohira, Tokyo (JP); and Akira Hikone, Tokyo (JP)
Assigned to TPR Co., Ltd., Tokyo (JP)
Appl. No. 18/839,495
Filed by TPR Co., Ltd., Tokyo (JP)
PCT Filed Nov. 16, 2022, PCT No. PCT/JP2022/042600
§ 371(c)(1), (2) Date Aug. 19, 2024,
PCT Pub. No. WO2023/162370, PCT Pub. Date Aug. 31, 2023.
Claims priority of application No. 2022-030032 (JP), filed on Feb. 28, 2022.
Prior Publication US 2025/0116331 A1, Apr. 10, 2025
Int. Cl. F16J 9/20 (2006.01)
CPC F16J 9/20 (2013.01) 6 Claims
OG exemplary drawing
 
1. A piston ring mounted on a piston of an internal combustion engine, comprising:
an outer circumferential surface provided on an outer circumference of the piston ring; an inner circumferential surface provided on an inner circumference of the piston ring; an upper surface facing a combustion chamber side in the internal combustion engine among axial end surfaces of the piston ring; and a lower surface positioned on a crank chamber side in the internal combustion engine among the axial end surfaces of the piston ring; wherein
the outer circumferential surface includes: an outer circumferential end surface including an outer circumferential end portion having a maximum diameter in the piston ring in a cross section orthogonal to a circumferential direction of the the piston ring; and a cut surface connecting the outer circumferential end surface and the lower surface so as to form a notched portion extending in the circumferential direction of the piston ring between the outer circumferential end surface and the lower surface;
the cut surface includes: a bottom portion positioned on an innermost side of the cut surface in a radial direction of the piston ring; a first surface provided between the outer circumferential end surface and the bottom portion and facing the crank chamber side; and a second surface provided between the bottom portion and the lower surface and facing outward in the radial direction;
the second surface is inclined away from a central axis of the piston ring as it extends toward the crank chamber side;
an angle of inclination of the second surface with respect to the lower surface in a cross section orthogonal to the circumferential direction of the piston ring is greater than or equal to 50° and less than or equal to 85°;
when an axial width of the piston ring is h1 and a distance in an axial direction between a connecting portion between the cut surface and the outer circumferential end surface and a connecting portion between the cut surface and the lower surface is H, H/h1 is greater than or equal to 0.2 and less than or equal to 0.4;
the connecting portion between the cut surface and the lower surface is positioned radially inward of the connecting portion between the cut surface and the outer circumferential end surface; and
the cut surface is configured to allow oil flowing along the second surface to escape to an outer circumferential side of the piston ring.