| 摘要 |
A combustion engine includes an engine valve arranged to selectively open/close a combustion chamber of the engine, a cylinder head adjacent the combustion chamber, arranged to guide a valve stem of the engine valve, the engine valve being axially displaceable relative to the cylinder head between the combustion chamber closed position and the combustion chamber fully opened position, and a valve spring retainer connected to the valve stem. The valve spring retainer partly delimits a gas spring volume, which is in fluid communication with an adjacent gas volume via a port when the engine valve is in the combustion chamber closed position, and which is separated from the adjacent gas volume when the engine valve is in the combustion chamber fully open position, the port being open during at least 25% of the maximal stroke of the engine valve and being closed due to a displacement of the engine valve. |
