| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve cooling performance of the crown surface of a piston for an internal combustion engine. <P>SOLUTION: A piston 18 for an internal combustion engine has the following configuration. An annular cooling channel 38 is configured to take in lubricating oil sprayed onto the rear surface of a piston head 18A from an oil jet, and to circulate the lubricating oil therein. The passage cross-section of the annular cooling channel is formed into a wide shape that its length in the piston radial direction is larger than its length in the piston axial direction. The wide shape of the passage cross-section of the cooling channel 38 shortens the length in the piston axial direction, suppresses vertical behavior of the lubricating oil due to inertia caused by piston's reciprocating motion, and increases the heat receiving area for receiving the quantity of heat from the piston crown surface. Consequently, it allows efficient cooling of the crown surface while suppressing air bubbles from being mixed into the lubricating oil, thereby improving cooling performance of the crown surface. <P>COPYRIGHT: (C)2013,JPO&INPIT |
