Highly heat conductive piston ring for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10344860-B2
Application number	US-201414911757-A
Country	US
Kind code	B2
Filing date	Sep 8, 2014
Priority date	Sep 9, 2013
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

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—Cr steel as a base material, the Mn—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.

First claim

What is claimed is:

1. A heat conductive piston ring for an internal combustion engine, comprising an Mn—Cr steel as a base material;
the Mn—Cr steel consisting of C in the range of from 0.52 mass % to 0.65 mass %, Si in the range of from 0.15 mass % to 0.35 mass %, Mn in the range of from 0.60 mass % to 1.00 mass %, Cr in the range of from 0.60 mass % 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 total content of Al, Ni, and Cu in the range of from 0.05 mass % to 3.0 mass %, and a remnant being Fe and unavoidable impurities,
wherein the Mn—Cr steel includes each of components Ai, Ni, and Cu in the range of from 0.01 mass % to 1.0 mass %, and wherein
a content of components Al, Ni, and Cu included in the Mn—Cr steel satisfies a relationship of formula (1) below

[

Formula
⁢

⁢
1

]

⁢

1.0
≤

[

Al
⁢

⁢
content
⁢

⁢

(

mass
⁢

⁢
%

)

]

+

[

Cu
⁢

⁢
content
⁢

⁢

(

mass
⁢

⁢
%

)

]

[

Ni
⁢

⁢
content
⁢

⁢

(

mass
⁢

⁢
%

)

]

≤
20.

(
1
)

2. The heat conductive piston ring for an internal combustion engine according to claim 1 , wherein
an outer circumferential surface of the piston ring comprises a hard film of any one or two or more types of a hard chrome plating, a hard ceramic, and a hard carbon.

3. The heat conductive piston ring for an internal combustion engine according to claim 1 , wherein
top and bottom surfaces and/or an inner circumferential surface of the piston ring is treated using at least one or two or more types of oxidation treatment, chemical conversion treatment, resin coating, and hard carbon film formation.

4. The heat conductive piston ring for an internal combustion engine according to claim 1 , wherein
a hardness after quench hardening and tempering is 40 HRC or more, and a thermal conductivity is 40 W/(m·K) or more.

Assignees

• Nippon Piston Ring Co Ltd
• Nissan Motor

Inventors

• Hirase Tsugane
• Yokokawa Hiromichi
• Fujimura Kazuhiro
• Ogawa Junpei
• Kondo Takaaki
• Miyazawa Tomonori
• Iguchi Toyoki
• Suzuki Takuma

Classifications

• Y10T428/12965

  Both containing 0.01-1.7% carbon [i.e., steel] · CPC title

• Y10T428/12958

  Next to Fe-base component · CPC title

• Y10T428/12951

  Fe-base component · CPC title

• F02F5/00

  Piston rings, e.g. associated with piston crown · CPC title

• C22C38/42 Primary

  with copper · CPC title