| 摘要 |
PROBLEM TO BE SOLVED: To reduce sliding friction by forming recesses in the upper and lower portions of the outer periphery of a valve lifter used in a valve operating mechanism of the internal combustion engine, and using the recesses as upper and lower retaining portions for retaining a lubricating oil therein. SOLUTION: A valve lifter. 1 is formed by a cylinder 2 having its upper end closed by a top portion 3, and is biased upward by a spring 63. The valve lifter 1 is vertically reciprocated in response to rotation of a cam abutting on the top portion 3. In this valve lifter 1, a plurality of equally spaced recesses are formed in an outer periphery 21 of the cylinder 2, and specifically, at the upper and lower portions along the outer periphery 21. These recesses function as upper and lower retaining portions 4, 5. Each recess has such a depth that a lubricating oil flowing above and below the valve lifter 1 can be retained in the retaining portions 4, 5. Thus, by enabling the lubricating oil to be retained in the upper and lower retaining portions 4, 5 of the valve lifter 1, friction between a guide hole and the upper and lower portions of the outer periphery 21 of the valve lifter 1 is reduced. As a result, smooth reciprocation of the valve lifter is assured.
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