Combination of piston ring for use in internal combustion engine
AssigneeNippon Piston Ring Co., Ltd.
InventorsMotonobu Onoda, Takao Sakai
Life of this patent
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Abstract
A piston ring combination including at least one compression ring and at least one oil ring. If a plurality of compression rings are provided, an outer peripheral surface of at least a top ring is formed with a first ion plating layer. The oil ring has a pair of side rails whose outer peripheral surfaces are formed with second ion plating layers. These layers are formed of Cr—N mixture. The first ion plating layer has a porous structure with a porosity ranging from 3 to 10% and a hardness ranging from 1000 to 1500 Hv. The second ion plating layer has a dense structure with a porosity ranging from 0 to 3% and a hardness ranging from 1800 to 2200 Hv.
Claims2
A combination of a piston rings for use in an internal combustion engine, the piston rings including at least one compression ring including a top ring having an outer peripheral surface formed with a first ion plating layer, and at least one oil ring having an outer peripheral surface formed with a second ion plating layer, the combination comprising:
- the first ion plating layer being formed of a mixture of Cr—N and having a porous structure with a first porosity ranging from 3 to 10%, and
- the second ion plating layer being formed of a mixture of Cr—N and having a dense structure with a second porosity ranging from 0 to 3%, wherein the first porosity and the second porosity are different.
Dependencies are inferred from the claim text.