Cylinder liner and cylinder bore
AssigneesTpr Co., Ltd., Tpr Industry Co., Ltd.
InventorsSeiji Tamaki, Takashi Oizumi
Life of this patent
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Abstract
Provided is a cylinder liner which can reduce the friction of the sliding surface from conventional levels and improve fuel efficiency without increasing oil consumption from conventional levels. When the inner circumferential surface of a cylinder liner or cylinder bore used in an internal combustion engine has a first sliding region, a second sliding region, and a third sliding region, and when respective surface roughness Rvk is from 0.05 μm to 0.3 μm, from 0.4 μm to 1.5 μm, and from 0.15 μm to 0.7 μm, a friction can be reduced while maintaining oil consumption.
Claims18
A cylinder liner used in an internal combustion engine wherein:
- an inner circumferential surface of the cylinder liner is formed with a plurality of cross hatches, wherein an angle of the cross hatches is 2° or more and 60° or less,
- the inner circumferential surface of the cylinder liner has a first sliding region, a second sliding region, and a third sliding region with different properties of the grooves in a piston sliding direction,
- the first sliding region, the second sliding region, and the third sliding region are continuous regions, and the first sliding region is located more toward a combustion chamber than the second sliding region,
- a surface roughness Rvk of the first sliding region is from 0.05 μm to 0.3 μm, a surface roughness Rvk of the second sliding region is from 0.4 μm to 1.5 μm, and a surface roughness Rvk of the third sliding region is from 0.15 μm to 0.7 μm, and
- the surface roughness Rvk of the first sliding region is smaller than the surface roughness Rvk of the third sliding region, and
- the surface roughness Rvk of the second sliding region is greater than the surface roughness of the first sliding region.
A cylinder bore used in an internal combustion engine, wherein:
- an inner circumferential surface of the cylinder bore is formed with a plurality of cross hatches, wherein an angle of the cross hatches is 2° or more and 60° or less,
- the inner circumferential surface of the cylinder bore has a first sliding region, a second sliding region, and a third sliding region with different properties of the grooves in a piston sliding direction,
- the first sliding region, the second sliding region, and the third sliding region are continuous regions, and the first sliding region is located more toward a combustion chamber than the second sliding region,
- a surface roughness Rvk of the first sliding region is from 0.05 μm to 0.3 μm, a surface roughness Rvk of the second sliding region is from 0.4 μm to 1.5 μm, and a surface roughness Rvk of the third sliding region is from 0.15 μm to 0.7 μm, and
- the surface roughness Rvk of the first sliding region is smaller than the surface roughness Rvk of the third sliding region, and
- the surface roughness Rvk of the second sliding region is greater than the surface roughness of the first sliding region.
Dependencies are inferred from the claim text.