| 摘要 |
<P>PROBLEM TO BE SOLVED: To equalize a temperature distribution around a cylinder bore by forming an anodic oxide coating on a sidewall of a water jacket. <P>SOLUTION: Since a water jacket 13 is formed on a cylinder block 11 so as to surround a cylinder bore 14 where a piston 15 slides, the cylinder block 11 having a temperature raised by an operation of an internal combustion engine is cooled by cooling water flowing through the water jacket 13, wherein an anodic oxide coating 21 superior in heat conductivity is formed on a sidewall 13a of the water jacket 13. Since the height H of the anodic oxide coating 21 in a high temperature part of the sidewall 13 is higher than the height H of the anodic oxide coating 31 in a low-temperature part, the calorific value released from the high temperature part to the cooling water is larger than that from the low-temperature part to the cooling water. Accordingly, a temperature of each part of the cylinder bore 14 is equalized to maintain circularity, and sliding resistance of the piston 15 relative to the cylinder bore 14 is reduced. <P>COPYRIGHT: (C)2012,JPO&INPIT |
