A pressurized fuel injection system for an engine includes a pressure sensor in a low pressure rail, an electronic pressure regulator valve in flow communication with and downstream from the low pressure rail and in flow communication with and upstream from a fuel supply, and a controller configured to receive a pressure signal from the pressure sensor and to control the electronic pressure regulator valve in response to the pressure signal to maintain a target pressure in the low pressure rail.

A pressurized fuel injection system for an engine includes a pressure sensor in a low pressure rail, an electronic pressure regulator valve in flow communication with and downstream from the low pressure rail and in flow communication with and upstream from a fuel supply, and a controller configured to receive a pressure signal from the pressure sensor and to control the electronic pressure regulator valve in response to the pressure signal to maintain a target pressure in the low pressure rail.

A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

A gas engine drive system includes: a gas engine including combustion chamber; a turbocharger including a compressor and turbine; a fuel injection system that injects fuel gas into intake air that is supplied from compressor to combustion chamber via an intake passage; a pressure detector detecting a charge air pressure; a temperature detector detecting the intake air's temperature; and controller controlling the fuel injection system. The controller: when required output decreases, determines the charge air pressure's lean limit based on target injection amount corresponding to required output that has decreased; if the charge air pressure is lower than or equal to the lean limit, decreases fuel injection amount to target injection amount; if the charge air pressure is higher than lean limit, brings fuel injection amount to zero. When the charge air pressure becomes lower than or equal to the lean limit, increases fuel injection amount to target injection amount.

An injection control device controls a solenoid in a fuel injection valve. The injection control device includes a transistor on an upstream side of a first power supply path to the solenoid and a transistor on an upstream side of a second power supply path to the solenoid. The injection control device has another transistor with a body diode arranged in parallel at a position on the first power supply path between the first transistor and an upstream terminal of the solenoid. The injection control device also includes a transistor on the downstream side of the first and second power supply paths. A drive controller in the injection control device drives the solenoid to an open position by switching ON the transistor on the downstream side and the transistor on the upstream side of the first power supply path or the transistor on the upstream side of the second power supply path.

The purpose of the present invention is to detect variations between the quantities of fuel injected into cylinders by fuel injection devices and correct the fuel injection quantity variation while minimizing the computational load on a drive device and the level of performance required of a pressure sensor. A drive device for fuel injection devices according to the present invention performs control wherein movable valves are driven so that predetermined quantities of fuel are injected by applying, for the duration of a set energization time, a current that will reach an energization current to solenoids of a plurality of fuel injection devices which open/close fuel flow paths. The drive device is characterized in that the set energization time or energization current is corrected on the basis of a pressure detection value from a pressure sensor that is attached to a fuel supply pipe disposed upstream of the plurality of fuel injection devices.

The purpose of the present invention is to detect variations between the quantities of fuel injected into cylinders by fuel injection devices and correct the fuel injection quantity variation while minimizing the computational load on a drive device and the level of performance required of a pressure sensor. A drive device for fuel injection devices according to the present invention performs control wherein movable valves are driven so that predetermined quantities of fuel are injected by applying, for the duration of a set energization time, a current that will reach an energization current to solenoids of a plurality of fuel injection devices which open/close fuel flow paths. The drive device is characterized in that the set energization time or energization current is corrected on the basis of a pressure detection value from a pressure sensor that is attached to a fuel supply pipe disposed upstream of the plurality of fuel injection devices.

A direct fuel injection engine including an ignition plug and a fuel injection valve arranged to be capable of injecting a fuel directly in a cylinder is controlled. The engine has a predetermined operation region in which an excess air ratio of an air-fuel mixture is set in a vicinity of 2. In a first region on a low load side of the predetermined operation region, a homogenous air-fuel mixture having the excess air ratio at a first predetermined value in the vicinity of 2 is formed upon combustion, and in a second region on a load side higher than the first region, a stratified air-fuel mixture having the excess air ratio at a second predetermined value in the vicinity of 2 is formed upon combustion.

An injection control device controls a fuel injection valve driven by an electric power. The injection control device includes a current detection unit to detect a driving current supplied to a solenoid of the fuel injection valve, an identification unit to identify a theoretical model of the driving current in a state where a movable core moved by an electromagnetic force generated by the solenoid is at rest, and a state detection unit to detect a state of the movable core. The state detection unit detects the state of the movable core, based on a deviation between the driving current detected by the current detection unit and the theoretical model.

An injection control device controls a fuel injection valve driven by an electric power. The injection control device includes a current detection unit to detect a driving current supplied to a solenoid of the fuel injection valve, an identification unit to identify a theoretical model of the driving current in a state where a movable core moved by an electromagnetic force generated by the solenoid is at rest, and a state detection unit to detect a state of the movable core. The state detection unit detects the state of the movable core, based on a deviation between the driving current detected by the current detection unit and the theoretical model.