| 摘要 |
PURPOSE:To accelerate the warming up of lubricating oil by invariably performing the injection of engine lubricating oil to the rear surface of a piston when the lubricating oil temperature is a predetermined value or lower and selectively performing the injection to suppress the occurrence of knocking when the temperature is the predetermined value or higher. CONSTITUTION:An oil pump 10 driven via a gear unit 11 and an oil pump 13 driven by a motor 14 are provided in the crankcase of an engine. The oil pump 13 draws the lubricating oil in an oil pan 3 via a strainer 15 and injects the lubricating oil to the rear surface of the top section 5a of a piston 5 via lubricating oil pipe 16, a lubricating oil feed passage 17, and a lubricating oil nozzle 18 to cool the piston 5. The motor 14 is controlled based on the lubricating oil temperature, etc.; it is inveriably driven at a predtermined temperature or lower and is selectively driven only when there is a possibility of the occurrence of knocking at the predtermined temperature or higher. |
