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U.S. Department of Energy
Office of Scientific and Technical Information

Exhaust gas recirculation system for internal combustion engines

Patent ·
OSTI ID:6470232

In an exhaust gas recirculation system for an internal combustion engine, a flow control valve is disposed within a recirculation pipe and operatively connected to a pneumatically operated servomotor to control the flow quantity of exhaust gases through the recirculation pipe, and an orifice is disposed within the recirculation pipe upstream of the valve to form a space between the valve and the orifice. A pressure regulator serves to modulate negative pressure from an engine intake manifold to the servomotor on a basis of pneumatic pressure applied thereto and pressure in the space. The pneumatic pressure applied to the pressure regulator is electrically controlled to satisfy the following equation. Pd f(Pv, n) where the character pd is the pneumatic pressure applied to the pressure regulator, and the characters pv and N respectively indicate the negative pressure in the intake manifold and the engine speed.

Assignee:
Nippon Soken Inc (Japan); Toyota Jidosha Kogyo K K (Japan)
Patent Number(s):
US 4242997
OSTI ID:
6470232
Country of Publication:
United States
Language:
English