Exhaust gas recirculation system

Claim 1

An exhaust gas recirculation system for internal combustion engines having an exhaust pipe and an intake pipe comprising: a pressure control chamber with a diaphragm arrangement for receiving a pressure signal, a shaft fixed to said diaphragm arrangement for reciprocally moving in accordance with said pressure signal, a valve body housing an inlet and outlet, a valve seat disposed in valve body housing between said inlet and outlet, said valve seat having a valve opening, a valve body fixed to said shaft and disposed in said valve housing, said valve body seating on said valve seat for opening and closing said valve opening in accordance with the reciprocal movement of said shaft so that said outlet is connected with said inlet when valve opening is opened, a bellows member fixed between said diaphragm arrangement and said valve body housing, and a detachable gasket member disposed between said valve body housing and said exhaust pipe, and having a flow control orifice at a position corresonding to said inlet, said flow control orifice being smaller than that of the valve opening of said valve seat so that the amount of exhaust gas flowing through said flow control orifice is thereby controlled, said exhaust pipe also having an opening at a position corresponding to said flow control orifice, whereby the exhaust gases of said engine flow from said exhaust pipe into said intake pipe through said opening, flow control orifice, and valve body housing when said diaphragm arrangement receives said pressure signal, while in the reverse condition, the exhaust gas flow is interrupted by said valve body, and said detachable gasket member can be easily cleared or renewed when said recirculation system has run over a limited period and further can be changed in compliance with the type of engine to match the dimension of said flow control orifice to the required exhaust gas flow rate specific to said type of engine.