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

Exhaust gas recirculation control device for diesel engine

Patent ·
OSTI ID:7226162
This patent describes an EGR control device for controlling an EGR value in a diesel engine, the EGR control device comprising: an electric control unit means for receiving input from an engine load sensor means for detecting engine load, an engine revolution sensor means for detecting an engine speed and a thermo-sensor means for detecting an engine temperature state. The electric control unit means has a first EGR MAP for preventing EGR under a low engine revolution idling speed during low engine temperature states, a second EGR MAP for permitting EGR under the low engine revolution idling speed during high engine temperature states, and a means for selecting either the first EGR MAP or the second EGR MAP in accordance with engine operating conditions. The first EGR MAP issues an output signal for EGR in a stage of fuel injection and an engine speed greater than a first predetermined engine speed that is higher than the idling speed and the second EGR MAP issues an output signal for EGR in the stage of fuel injection and at an engine speed greater than a second predetermined engine speed that is lower than the idling speed; and an electric vacuum regulating valve means connected to the electric control unit means and receiving an output signal therefrom. The electric vacuum regulating valve means regulates an opening degree of the EGR valve in accordance with the output signal from the electric control unit.
Assignee:
Toyota Jidosha Kabushiki Kaisha
Patent Number(s):
US 4625702
OSTI ID:
7226162
Country of Publication:
United States
Language:
English