摘要 |
PROBLEM TO BE SOLVED: To bring coefficients of linear expansion of a cylinder block and a cylinder head close to a coefficient of linear expansion of a timing chain by a stiffener, to suppress an increase in center distance between a crank shaft and a camshaft caused by thermal expansion, and to prevent the increase in tension of the timing chain. SOLUTION: A cam sprocket and a crank sprocket are connected through the timing chain, and a timing chain guide for restricting the timing chain is provided. The timing chain is formed by a member with smaller coefficient of linear expansion than at least one of the coefficients of linear expansion of the cylinder head and the cylinder block, and the stiffener is formed by a member with a coefficient of linear expansion similar to or smaller than that of the timing chain. The stiffener is provided so as to stride across a jointing surface of the cylinder block and the cylinder head, and an upper portion of the stiffener is secured to the cylinder head while a lower portion of the stiffener is secured to the cylinder block.
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