Engine- and vehicle- speed-based engine cooling fan control

摘要

An engine cooling fan (18) is coupled to an engine (14) of a truck (10) through an electric-operated clutch (20) for selectively placing the cooling fan in driven and non-driven relationship with the engine. A control system (22) processes certain data for indicating when engine speed (N) exceeds a reference engine speed (EFC_N_LMX), for indicating when vehicle speed (VSS) exceeds a reference vehicle speed EFC_VSS_LMX), and for indicating when rate of change of engine speed exceeds a selected rate of change of engine speed. The clutch places the fan in non-driven relationship with the engine when the processing discloses vehicle speed exceeding the reference vehicle speed coincident with the processing of the data disclosing either engine speed exceeding the reference engine speed or rate of change of engine speed exceeding the selected rate of change of engine speed.