Internal-combustion engine cylinder block and production method therefor
AssigneeHonda Motor Co., Ltd.
InventorsKoji Kobayashi, Kaoru Kojina, Nobuhiko Yoshimoto, Junya Funatsu
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Abstract
In an internal-combustion engine cylinder block, a SiC interlayer and a DLC film are formed on an inner wall of a cylinder bore. Expressions (1)-(3) are satisfied when T1 is the film thickness of the SiC interlayer and T2 is the film thickness of the DLC film. (1) T1≧0.2 μm. (2) T1<T2. (3) T1+T2≧7 μm. Preferably, 0.2 μm≦T1≦1 μm, and 7 μm≦T1+T2≦13 μm.
Claims11
A cylinder block for an internal-combustion engine comprising a block base containing an aluminum alloy, an inner wall of a cylinder bore in the block base being covered with a diamond-like carbon film,
- wherein
- an intermediate SiC film is formed between the inner wall and the diamond-like carbon film, and
- the thickness T1 of the intermediate SiC film and the thickness T2 of the diamond-like carbon film satisfy the following inequalities (1) to (3):
- T1≧0.2 μm, (1)
- T1<T2, (2)
- T1+T2≧7 μm. (3)
A method for producing a cylinder block for an internal-combustion engine having a block base containing an aluminum alloy, an inner wall of a cylinder bore in the block base being covered with a diamond-like carbon film,
- wherein
- the method comprises, in a plasma chemical vapor deposition process using the block base as a negative electrode and using a first closing member and a second closing member configured to close the cylinder bore as a positive electrode,
- a film formation step of supplying an SiC source gas to an inside of the cylinder bore to form an intermediate SiC film on the inner wall and
- a film formation step of stopping supply of the SiC source gas and of supplying a diamond-like carbon source gas to the inside of the cylinder bore having the intermediate SiC film to form the diamond-like carbon film (22) on the intermediate SiC film,
- plasma gases used in the film formation steps have a temperature of 130° C. to 190° C., and
- the film formation steps are carried out in such a manner that the thickness T1 of the intermediate SiC film and the thickness T2 of the diamond-like carbon film satisfy the following inequalities (1) to (3):
- T1≧0.2 μm, (1)
- T1<T2, (2)
- T1+T2≧7 μm. (3)
Dependencies are inferred from the claim text.