Rotary-actuated exhaust gas recirculation valve having a seating force attenuator

摘要

Means for attenuating the seating force of a cam-actuated poppet valve such as an exhaust gas recirculation valve in an internal combustion engine including a shock-absorber disposed between the valve stem and valve head. In a currently preferred embodiment, the shock-absorber is a wave washer disposed around the valve stem and captured between the valve stem and the valve head, between which axial motion is allowed. After the valve head engages the valve seat to close the valve, any further travel of the actuator cam and valve stem is absorbed by compression of the wave washer, thus attenuating additional force on elements of the valve actuation train. In opening the valve, the reverse occurs, in that initial motion of the actuator cam and valve stem serves to relieve compression of the wave washer, followed by removal of the valve head from the valve seat.