| 摘要 |
PROBLEM TO BE SOLVED: To provide a valve mechanism for an internal combustion engine capable of suppressing deterioration due to heat of an oil seal. SOLUTION: A thermal insulating part 25 having lower heat conductivity than that of a shaft part 20 of an exhaust valve 5 being one example of a valve for the internal combustion engine is provided in an end part of the shaft part 20 of the exhaust valve 5. The oil seal 50 comes into contact with the thermal insulating part 25. A valve guide 40 having higher heat conductivity than that of the shaft part 20 comes into contact with the shaft part 20. Since a hollow part 21 sealing refrigerant 30 in it is formed in the exhaust valve 5, heat received by an umbrella part 10 from a combustion chamber is transmitted to each part of the shaft part 20 by flowing-in of refrigerant 30 in the hollow part 21, and a part of heat is transmitted to the valve guide 40 from the shaft part 20 for heat radiation. Since the thermal insulating part 25 has low heat conductivity and heat is not easily transmitted, heat is not easily transmitted to the oil seal 50. As a result, deterioration due to heat of the oil seal is suppressed. COPYRIGHT: (C)2006,JPO&NCIPI
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