| 摘要 |
EGR assembly of an internal combustion engine, which uses a poppet valve, as a fluid-intercepting member, and which comprises an electric motor (1) , the shaft of which drives the valve stem through a gear reduction mechanism comprising a rack (6) and pinion (5) coupling, as well as emergency shutting spring means (4) which push said valve into its shutting position. According to the invention, the rack is a separate member from the valve, sliding according to the valve axis and which controls it through axial pressure on the valve stem. The rack is slidable along said axis by a run which is greater than the valve run. Electronic control means feed said electric motor with at least an initial power impulse, which moves the rack in a short run away from the valve stem, followed by an initial approaching and impact run. A position sensor (15) is further provided, capable of detecting the axial position of the valve (2) with respect to the seat thereof . |
