| 摘要 |
<P>PROBLEM TO BE SOLVED: To avoid increase in manufacturing cost, and to restrain oil from receiving heat. <P>SOLUTION: In a downside oil passage 224, a wall surface shape of the oil passage 224 is formed to form an air layer 225a between a wall surface (first widened portion 225) on the cylinder bore side of the oil passage 224 and the oil flowing down inside it, in a range (downstream-side area HA), which receives heat from the cylinder bore 223, of the oil passage 224. Specifically, on the wall surface 4 of the oil passage 224, the first widened portion 225 widened to the side of the cylinder bore 223 is formed in the downstream-side area HA, which is the range receiving the heat from the cylinder bore 223, of the oil passage 224. A first inclined portion 227, which is inclined obliquely downward toward the inside from the side of the cylinder bore 223 (toward the right side in Fig.5), is formed in an upper end position of the first widened portion 225 on the wall surface of the oil passage 224. <P>COPYRIGHT: (C)2013,JPO&INPIT |
