PUMP CONTROL APPARATUS FOR FUEL SUPPLY SYSTEM OF FUEL-INJECTION ENGINE

摘要

An estimated fuel consumption quantity corresponding to a fuel injection timing of an engine is reduced or set to zero if failure of the corresponding injector has been detected. A pump control apparatus controls a fuel supply pump to maintain the pressure in a common rail at a target value by control of a command delivery quantity supplied from the pump to the common rail in correspondence with each injection timing. Each command delivery quantity is determined based on a necessary delivery quantity and on a feedback quantity, which is derived from a difference between previously obtained values of command delivery quantity and of a corresponding actual delivery quantity from the pump. Prior to the injection, a pressure compensation quantity is calculated, as a fuel quantity required to bring the fuel rail pressure to the target pressure value, and is added to the fuel consumption quantity to obtain the necessary delivery quantity.

主权项

1. A pump control apparatus for application to a fuel supply system, the fuel supply system incorporating a fuel supply pump which impels fuel to a common rail to be stored under a common rail pressure and supplied from the common rail to respective injectors of an internal combustion engine, to be injected at injection timings respectively corresponding to the fuel injectors;
the pump control apparatus comprising: injection condition detection means configured to detect respective injection conditions of the fuel injectors, consumption quantity determining means configured to determine a fuel consumption quantity for each of the fuel injectors, at a current injection timing of the fuel injector, based on information including the injection condition of the fuel injector, pressure compensation quantity determining means configured to determine a pressure compensation quantity prior to the current injection timing, based upon a difference between the common rail pressure and a target pressure value, as a fuel quantity required to be supplied to the common rail for setting the common rail pressure at a target pressure value, necessary delivery quantity determining means configured to determine a necessary delivery quantity based upon a total of the fuel consumption quantity and the pressure compensation quantity, as a fuel quantity required to be impelled to the common rail from the fuel supply pump subsequent to the current injection timing for setting the common rail pressure at the target pressure value, actual delivery quantity detection means configured to detect an actual delivery quantity as a quantity of fuel actually impelled from the fuel supply pump to the common rail, feedback means configured for determining a feedback quantity based upon a difference between values of necessary delivery quantity and actual delivery quantity respectively corresponding to a preceding injection timing of the fuel injector, command delivery quantity determining means configured for determining a command delivery quantity of fuel as a total of the feedback quantity and the necessary delivery quantity respectively corresponding to the current injection timing of the fuel injector, and pump control means configured to control the fuel supply pump to impel the command delivery quantity of fuel into the common rail.