Nippon Piston Ring Co., Ltd.

Nissan Motor Company Limited

Tsugane Hirase

Takuma Suzuki

Katsuaki Ogawa

Toyoki Iguchi

Kazuhiro Fujimura

Iwao Hiraishi

Tomonori Miyazawa

Kazuhiro Sameshima

Hiromi Ishikawa

Junpei Ogawa

Takaaki Kondo

Hiromichi Yokokawa

There is provided a highly heat conductive piston ring for an internal combustion engine capable of exhibiting a gas seal function and a heat transfer function for a long period of time in a stable manner when used in an automobile gasoline engine having a high compression ratio. The highly heat conductive piston ring for an internal combustion engine is a piston ring for an internal combustion engine having an Mn&#x2014;Cr steel as a base material, the Mn&#x2014;Cr steel including C in the range of from 0.52 to 0.65 mass %, Si in the range of from 0.15 to 0.35 mass %, Mn in the range of from 0.60 to 1.00 mass %, Cr in the range of from 0.60 to 1.00 mass %, P in the range of 0.04 mass % or less, S in the range of 0.04 mass % or less, a slight amount of components (total content of Al, Ni, and Cu) in the range of from 0.05 to 3.0 mass %, and a remnant being Fe and unavoidable impurities.

Highly heat conductive piston ring for internal combustion engine

A combination of a cylinder liner and a piston ring, wherein the cylinder liner includes, silicon: 23.0-28.0% by weight, magnesium: 0.80-2.0% by weight, copper: 3.0-4.5% by weight, iron: 0.25% by weight or less, nickel: 0.01% by weight or less, wherein surface roughness profile of the inner circumference surface has Rz=0.5 to 1.0 &#x3bc;m, Rk=0.2 to 0.4 &#x3bc;m, Rpk=0.05 to 0.1 &#x3bc;m, Rvk=0.08 to 0.2 &#x3bc;m, wherein the piston ring includes carbon: 0.6-0.7% by weight, chrome: 13-14% by weight, molybdenum: 0.2-0.4% by weight, silicon: 0.25-0.50% by weight, manganese: 0.2-0.5% by weight, and wherein carbides with the diameter of 5.0 &#x3bc;m and less are 4-10%.

Combination of a cylinder liner and a piston ring

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Ichinoseki, Japan

Tsugane Hirase