| 摘要 |
<p>PURPOSE:To change an open-close characteristic so as to increase an operation characteristic control accuracy of an intake valve, and to solve a problem based on a hydraulic control so as to control a valve system over all the engine operation ranges by controlling the hydraulic releasing time of a hydraulic chamber, in a valve system of an internal combustion engine which is capable of opening and closing an intake valve arranged plurally to each cylinder, with a characteristic suitable for engine operation states. CONSTITUTION:At least two of the following three control modes are changed selectively according to engine driving states. One is that to carryout valve action characteristic change control of a hydrolic valve drive means 29 and also to stop the valve driving of a mechanical valve drive means 30. Another is that to at least stop the valve action characteristic change control of the hydraulic valve drive means 29. The last is that to carry out the valve action characteristic change control of hydraulic valve drive means 29 and also to drive the valve of mechanical valve drive means 30.</p> |
