| 摘要 |
An exhaust gas recirculation system (11) for an internal combustion engine, including a valve (25) having a closed position (FIG. 2) blocking flow of exhaust gas, the valve being biased by gas pressure in the exhaust gas passage (E) toward a closed position (FIG. 2). The system includes an electric motor (51) having an input gear (55) and a gear train (57,59) driving a sector gear (73). A linkage member (93) has its ends (91,95) connected to the sector gear (73) and the valve stem (29), respectively. The sector gear and the linkage member are configured such that, as the valve begins to open against exhaust gas pressure, the movement of the valve stem is a relatively higher force, and at a relatively lower speed. As the valve moves toward a fully open position (FIG. 7), the movement of the valve stem is at a relatively lower force, but at a relatively higher speed. <IMAGE> |
