Patent ID: 7185634
Filing Date: 2007-03-06
Classification: F01L,F02D,F02M

Abstract:
1. A pump system for use in engines having hydraulically actuated elements requiring fluid under pressure from a high pressure rail on each actuation load event, the load events being referenced to the engine crankshaft angle, comprising: a pump; a high pressure rail; a pressure sensor coupled to sense the pressure in the high pressure rail; a valve coupled to controllably cause an output of the pump to pass to the high pressure rail or to return to a pump input; a crankshaft angle sensor; and, a controller coupled to the pressure sensor, the valve and the crankshaft angle sensor, the controller controlling the valve after a load event to cause an output of the pump to return to a pump input; the controller also being responsive to the pressure sensor and the crankshaft angle sensor to control the valve to cause an output of the pump to pass to the high pressure rail starting at a crankshaft angle preceding the crankshaft angle of a coming load event by an amount dependent on the existing rail pressure and a first desired pressure at the beginning of the load event.