Abstract: A drive control method of a flow rate control valve in a common rail type fuel injection control apparatus, in which an integral value of a difference between a target current and an actual current is used in feedback control of an energization current of the flow rate control valve such that the actual current of the flow rate control valve becomes closer to the target current, the flow rate control valve controlling an amount of fuel supplied to a high pressure pump that pressure feeds high pressure fuel to a common rail.

Abstract: To facilitate early stabilization of an integral value at the time of start up and improve stability and responsiveness of a rail pressure control. When an ignition switch 11 is turned on, an initial value for an integral calculation that calculates an integral value of a difference between a target current and an actual current of a flow rate control valve 6 is set to a predetermined value to supply the target current at that time point to the flow rate control valve 6 (S102, S104). In addition, a second integral gain K2 that is larger than a first integral gain K1, which is used under normal conditions, is set as an integral gain K in the integral calculation during a predetermined time period To after the ignition switch 11 is turned on, while the first integral gain K1 is set as the integral gain after the predetermined time period To elapses (S106 to S108).

Abstract: In an exhaust gas cleaning apparatus (30) in which a before and after differential pressure (?P) of a filter (32) used to trap particulates is detected for regeneration of the filter (32), a time at which, during filter regeneration, the temperature of the outlet section of the filter (32) falls below the temperature of the inlet section thereof (?T>M), using a first temperature sensor (36) and a second temperature sensor (37), is determined as being the timing of the completion of the regeneration of the filter (32). The value of the before and after differential pressure (?P) at the time of this regeneration completion is used to estimate the quantity of residual ash in the filter (32), and when this estimated residual ash quantity is the same as, or greater than, a prescribed value (PX), a replacement warning signal (K3) is output urging replacement of the filter (32).

Abstract: In an exhaust gas cleaning apparatus (30) in which a before and after differential pressure (&Dgr;P) of a filter (32) used to trap particulates is detected for regeneration of the filter (32), a time at which, during filter regeneration, the temperature of the outlet section of the filter (32) falls below the temperature of the inlet section thereof (&Dgr;T>M), using a first temperature sensor (36) and a second temperature sensor (37), is determined as being the timing of the completion of the regeneration of the filter (32). The value of the before and after differential pressure (&Dgr;P) at the time of this regeneration completion is used to estimate the quantity of residual ash in the filter (32), and when this estimated residual ash quantity is the same as, or greater than, a prescribed value (PX), a replacement warning signal (K3) is output urging replacement of the filter (32).