Exhaust gas re-circulation device for an internal combustion engine

摘要

An exhaust gas re-circulation device for an internal combustion engine comprises an intake air channel (2), an intake air control valve (18), an exhaust gas re-circulation valve (12) and an actuator (22), a first motion transmission mechanism between the actuator (22) and the exhaust gas re-circulation valve (12) and a second motion transmission mechanism between the actuator (22) and the intake air control valve (18). A first uncoupling means (26) is included in the first motion transmission mechanism and a first pull-back spring (34) biases the exhaust gas re-circulation valve (12) in a closed position. The device enables to control exhaust gas re-circulation rates by simultaneously driving the two valves in opposite senses and to obtain a smooth engine shut-off, by simultaneously closing the two valves. In a preferred embodiment, with a second uncoupling means (50) in the second motion transmission mechanism and a second pull-back spring (52) biasing the intake air control valve (18) in an open position, low exhaust gas re-circulation rates can be controlled with the intake air control valve (18) fully open.