CONTROL SYSTEM AND METHOD FOR CONTROLLABLE OUTPUT TYPE HYDRAULIC FLUID PUMP OF AUTOMATIC TRANSMISSION PROVIDING DECREASED PUMP OUTPUT IN ASSOCIATION WITH THE ENGINE STARTING CONDITION

摘要

ABSTRACT Of THE DISCLOSUREAn automatic transmission, for a vehicle with an engine, includes ahydraulic fluid pump which supplies pressurized hydraulic fluid. It isdetected whether or not the engine is being started, and the pump output iscontrolled so as to be decreased when the engine is being started. If thepump is one whose output per one revolution of its input member isvariable, then its output may be thus controlled by decreasing its outputper one revolution when the engine is being started. And, if the pump is avariable capacity type vane type hydraulic fluid pump the output of whichper one revolution of its input member is controlled by varying theeccentric position of a controlling member thereof, then its output per onerevolution may be thus controlled by varying this eccentric position to givea pump output per one revolution decreased when the engine is beingstarted. Alternatively, if the pump is a fixed capacity type electricallydriven type hydraulic fluid pump the output of which per one revolution ofits input member is substantially constant, then its output may be thuscontrolled by decreasing the rotation speed of its input member, possibly tozero, when the engine is being started. A system for implementing thismethod is also disclosed.