Fuel supply device and fuel supply control method for internal combustion engine

摘要

A fuel supply device includes a low-pressure fuel pump, a high-pressure fuel pump, an accumulator for accumulating the pressurized fuel, fuel injection valves, a relief valve for restricting an upper limit value of a fuel pressure in the accumulator, a high-pressure fuel pressure sensor, and a control unit for setting a target fuel injection pressure, controlling the high-pressure fuel pump so that the fuel pressure in the accumulator reaches the target fuel injection pressure, and regarding the present target fuel injection pressure as a detection value of the high-pressure fuel pressure sensor and setting the high-pressure fuel pump in an operational state with a maximum discharge amount or a non-operational state when detecting an abnormality of the high-pressure fuel pressure sensor.;This enables the fuel to be injected with an appropriate injection pulse width corresponding to an actual fuel pressure even if the high-pressure fuel pressure sensor experiences disconnection.

主权项

1. A fuel supply device for an internal combustion engine, comprising:
a low-pressure fuel pump for sucking fuel from a fuel tank; a high-pressure fuel pump for pressurizing the fuel discharged from the low-pressure fuel pump; an accumulator for accumulating the fuel pressurized by the high-pressure fuel pump, fuel injection valves for directly injecting the fuel accumulated in the accumulator into cylinders of an internal combustion engine; a relief valve for restricting an upper limit value of a fuel pressure in the accumulator; a high-pressure fuel pressure sensor for detecting the fuel pressure in the accumulator and a control unit for setting a target fuel injection pressure corresponding to an engine operating state, controlling the high-pressure fuel pump based on a detection value of the high-pressure fuel pressure sensor and the target fuel injection pressure so that the fuel pressure in the accumulator reaches the target fuel injection pressure and setting a fuel injection pulse width of the fuel injection valves based on the detection value of the high-pressure fuel pressure sensor; wherein the control unit determines the presence of an abnormality of the high-pressure fuel pressure sensor when a period during which an outlier is detected has exceeded a threshold value set in advance and, when determining the presence of the abnormality of the high-pressure fuel pressure sensor, sets the high-pressure fuel pump in an operational state with a maximum discharge amount or sets the high-pressure fuel pump in a non-operational state, and regards the target fuel injection pressure at the time of determining the presence of the abnormality of the high-pressure fuel pressure sensor as the detection value of the high-pressure fuel pressure sensor and sets the fuel injection pulse width of the fuel injection valves based on the value regarded as the detection value of the high-pressure fuel pressure sensor.