Patent ID: 7240667
Filing Date: 2007-07-10
Classification: F02D,F02M

Abstract:
1. A method for controlling the rail pressure (pCR) of a common rail system, comprising the steps of: determining a rail pressure control deviation (dp) from a comparison of a desired and an actual rail pressure, calculating a rail pressure control value from the rail pressure control deviation (dp) for the operation of a suction throttle control valve ( 4 ) via a rail pressure controller ( 11 ), wherein fuel admission to a high pressure pump ( 5 ) and consequently the rail pressure (pCR) is determined, determining from the rail pressure control value a desired current value (i(SL)) serving as guide value for a current control circuit ( 14 ) and for the calculation of a preliminary control value (U 2 ), calculating an actual current value (i(IST)) via filters ( 22 , 23 ) from a suction throttle valve current (i) which flows through the winding of the suction throttle valve ( 4 ), determining a first control value (U 1 ) via a current controller ( 17 ) from a current control deviation (di) of the desired current value (i(SL)) from the actual current value (i(IST)), and determining the suction throttle valve current (i) by the first control value (U 1 ) and the preliminary control value (U 2 ).