| 摘要 |
<p>An internal combustion engine has electrically controlled hydraulic linkages (64) between engine cams (40) and engine cylinder valves (30). If it is desired to skip a cam lobe (42a, 42b, 42c) or to modify the response of an engine cylinder valve to a cam lobe (42a, 42b, 42c), hydraulic fluid is selectively released from the associated hydraulic linkage (64) to permit lost motion between the cam (40) and the engine cylinder valve (30). Electrically controlled hydraulic fluid valves (100) are used to produce the selective release of hydraulic fluid from the hydraulic linkages (64). The mode of operation of the engine can be changed (e.g., from positive power mode to compression release engine braking mode or vice versa), or more subtle changes can be made to modify the timing and/or extent of engine cylinder valve openings to optimize engine performance for various engine or vehicle operating conditions (e.g., different engine or vehicle speeds).</p> |
