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

Exhaust gas recirculation control system for internal combustion engine

Patent ·
OSTI ID:6509715

An exhaust gas recirculation control system for controlling the amount of exhaust gas subjected to recirculation to the air inlet depending on the amount of inlet air of an internal combustion engine is described. This system comprises a control valve disposed in an exhaust gas recirculation passage, for controlling the amount of exhaust gas recirculation, an orifice disposed in the recirculation passage, for creating a negative pressure upstream of the control valve, and a solenoid valve for generating a pressure which controls the control valve. The solenoid valve comprises a core formed therein with a hollow passage opened at one end to a valve portion, a plunger made of a magnetic material and having a valve seat opposing the open end to define the valve portion, a spring biasing the plunger in the opening direction of the valve portion, a first exciting coil generating, when passing therethrough a current proportional to the amount of inlet air, a force acting on the plunger to close the valve portion, and a second exciting coil generating, when passing therethrough a current in inverse proportion to the pressure downstream of the orifice, a force opposite to the force on the plunger due to the first exciting coil.

Assignee:
Hitachi Ltd (Japan)
Patent Number(s):
US 4231340
OSTI ID:
6509715
Country of Publication:
United States
Language:
English