# US 7,607,414 B2 · Member for internal combustion engine and production method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,607,414 B2 - Document ID: US7607414B2 - Status: Granted - Kind: B2 - Application number: 11/224,300 - Filed: 2005-09-13 - Published: 2006-03-16 - Granted: 2009-10-27 - Earliest claimed: 2004-09-14 - Assignees: Nissan Motor Co., Ltd. - Inventors: Seiji Kamada; Hiroshi Kumagai; Midori Kondou; Kenji Kikuchi; Takumaru Sagawa; Yutaka Mabuchi; Takahiro Nakahigashi - Web page: https://patentgrep.com/patent/US7607414B2 ## CPC - F01L 3/04: Coated valve members or valve-seats - F02B 77/02: Surface coverings of combustion-gas-swept parts (of pistons F02F3/10; of cylinders and cylinder heads F02F1/00) - F02F 3/12: on piston heads - Y10T 29/49231: I.C. [internal combustion] engine making - Y10T 29/49263: by coating or cladding - F01L: CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - F02F: CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A member for an internal combustion engine, such as a piston, a valve and a fuel injection valve. The member includes a substrate. A carbon-based coating film is formed on the substrate to cover at least a part of a region of the substrate to which region fuel for the internal combustion engine is contactable. The carbon-based coating film contains fluorine and has a thickness of 10 μm or less. ## Claims ### Claim 1 A member for an internal combustion engine, comprising: a substrate; and a carbon-based coating film formed on the substrate to cover at least a part of a region of the substrate to which region fuel for the internal combustion engine is contactable, the carbon-based coating film containing fluorine and having a thickness of 10 μm or less, wherein the carbon-based coating film has a fluorine and carbon content of (fluorine/carbon) ≧0.25 in atomic number ratio. ### Claim 2 (depends on 1) The member for an internal combustion engine, as claimed in claim 1, wherein the carbon-based coating film has a thickness within a range of from 0.05 to 5 μm. ### Claim 3 (depends on 1) The member for an internal combustion engine as claimed in claim 1, wherein the fluorine and carbon content in a region of from an uppermost surface to a depth of 4 nm in the carbon-based coating film is (fluorine/carbon) ≧0.4 in atomic number ratio. ### Claim 4 (depends on 1) The member for an internal combustion engine, as claimed in claim 1, wherein the fluorine and carbon content in a region of from an uppermost surface to a depth of 4 nm in the carbon-based coating film is (fluorine/carbon) ≧1 in atomic number ratio. ### Claim 5 (depends on 1) The member for an internal combustion engine as claimed in claim 1, wherein a fluorine content in the carbon-based coating film is largest at an uppermost surface portion of the carbon-based coating film and decreases with approach to the substrate. ### Claim 6 (depends on 1) The member for an internal combustion engine as claimed in claim 1, further comprising a middle layer film containing at least one of carbon and silicon, wherein the middle layer film is located between an uppermost film and the substrate. ### Claim 7 (depends on 1) The member for an internal combustion engine as claimed in claim 1, wherein the substrate has a surface roughness (Ra) ranging from 0.1 to 3 μm. ### Claim 8 (depends on 1) The member for an internal combustion engine as claimed in claim 1, wherein the member is subjected to a heat treatment at a temperature ranging from 80 to 270° C. after formation of the carbon-based coating film. ### Claim 9 A piston for an internal combustion engine, comprising: a substrate, wherein the substrate is a piston body; and a carbon-based coating film formed on the piston body to cover at least a part of a region of the piston body to which region fuel for the internal combustion engine is contactable, the carbon-based coating film containing fluorine and having a thickness of 10 μm or less, wherein the carbon-based coating film has a fluorine and carbon content of (fluorine/carbon) ≧0.25 in atomic number ratio, wherein at least a crown surface of the piston body is coated with the carbon-based coating film. ### Claim 10 A valve for an internal combustion engine, comprising: a substrate, wherein the substrate is a valve body; and a carbon-based coating film formed on the valve body to cover at least a part of a region of the valve body to which region fuel for the internal combustion engine is contactable, the carbon-based coating film containing fluorine and having a thickness of 10 μm or less, wherein the carbon-based coating film has a fluorine and carbon content of (fluorine/carbon) ≧0.25 in atomic number ratio. wherein at least a part selected from the group consisting of a valve stem, a valve head and a surface portion at a side of a combustion chamber is coated with the carbon-based coating film. ### Claim 11 A fuel injection valve for an internal combustion engine, comprising: a substrate, wherein the substrate is a fuel injection valve body; and a carbon-based coating film formed on the fuel injection valve body to cover at least a part of a region of the fuel injection valve body to which region fuel for the internal combustion engine is contactable, the carbon-based coating film containing fluorine and having a thickness of 10 μm or less, wherein the carbon-based coating film has a fluorine and carbon content of (fluorine/carbon) ≧0.25 in atomic number ratio, wherein at least an inner surface of the injection valve body, defining an injection hole, is coated with the carbon-based coating film. ### Claim 12 A method of producing a member for an internal combustion engine, the member including a substrate; and a carbon-based coating film formed on the substrate to cover at least a part of a region of the substrate to which region fuel for the internal combustion engine is contactable, the carbon-based coating film containing fluorine and having a thickness of 10 μm or less, the method comprising: forming the carbon-based coating film on the substrate by a vapor phase deposition process, wherein the carbon-based coating film has a fluorine and carbon content of (fluorine/carbon) ≧0.25 in atomic number ratio. ### Claim 13 (depends on 12) The method of producing a member for an internal combustion engine as claimed in claim 12, further comprising exposing a surface of the substrate to plasma of at least one gas selected from the group consisting of fluorine gas, hydrogen gas, oxygen gas and rare gas, before forming the carbon-based coating film. ### Claim 14 (depends on 13) The method of producing a member for an internal combustion engine as claimed in claim 13, wherein the substrate is formed of stainless steel, and the at least one gas is rare gas. ### Claim 15 (depends on 12) The method of producing a member for an internal combustion engine as claimed in claim 12, wherein the vapor phase deposition process is plasma CVD. ### Claim 16 (depends on 15) The method of producing a member for an internal combustion engine as claimed in claim 15, wherein hydrocarbon gas and fluorine-based gas in the plasma CVD are used as source gas for deposition. ### Claim 17 (depends on 12) The method of producing a member for an internal combustion engine as claimed in claim 12, further comprising carrying out a heat treatment at a temperature ranging from 80 to 270° C. on the member after the formation of the carbon-based coating film.