| 摘要 |
A large two-stroke diesel engine with an electronically controlled exhaust valve actuation system includes for each cylinder an exhaust valve with a valve stem and a valve disc, an air spring operably connected to the valve stem and urging the exhaust valve towards the closed position, a hydraulic actuator operably connected to the exhaust valve, an electronically controlled hydraulic system that selectively connects the hydraulic actuator to a source of high pressure hydraulic fluid for a first short period at the start of the opening stroke of the exhaust valve, and an intermediate pressure hydraulic accumulator for a period immediately following the first short period until the exhaust valve has reached it open position, the intermediate pressure hydraulic accumulator from the start of the closing stroke of the exhaust valve until the start of a last short period at the end of the closing stroke of the exhaust valve, and to tank during the last short period of the closing stroke of the exhaust valve.
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