| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance cooling performance of a piston of an internal combustion engine with a simple constitution. <P>SOLUTION: A first oil chamber 5 changing the volume in response to a sliding amount of an upper piston 3 and a biasing chamber 6 keeping a biasing member 4 therein are formed between a lower piston 2 and upper piston 3. A sliding surface 7 to which the lower piston 2 and upper piston 3 are mutually slidably contact is arranged adjacently to the biasing chamber 6. While an oil hole 3t passing through an outer peripheral surface 3e of the upper piston 3 to the sliding surface 7 is provided, a first passage 2p is formed in the lower piston 2. The communicating state of the oil hole 3t and first passage 2p is changed according to the change in the volume of the combustion chamber 16. Second passages 3m, 3p for communicating between the first oil chamber 5 and biasing chamber 6 are provided in the upper piston 3. <P>COPYRIGHT: (C)2013,JPO&INPIT |
