ABGAS-RUECKFUEHRUNGSSYSTEM FUER EINE BRENNKRAFTMASCHINE

摘要

An exhaust gas recirculation system for an internal combustion engine comprising an exhaust gas recirculation passage for recirculating exhaust gases from an exhaust pipe into an intake pipe downstream of a throttle valve, a control valve responsive to a pressure signal for opening or closing said recirculation passage, a pressure chamber defined within the recirculation passage, a negative pressure control valve to which is transmitted a negative throttle pressure generated at a throttle port at a position upstream of the throttle valve when the latter is completely closed and which controls said negative throttle pressure in response to the load on the engine, and a modulator wherein the pressure from the pressure chamber acts on one surface of a diaphragm while the negative output pressure from the negative pressure control valve acts on the other surface of the diaphragm so that the modulator may control the pressure signal in response to the difference between said two pressures acting on the diaphragm, whereby the amount of exhaust gases recirculated may be made proportional to the load on the engine regardless of the variation in rotational speed of the engine.