A high-pressure pump includes a plunger that varies a volume of a pressurizing chamber, and a control valve that controls supply of fuel into the pressurizing chamber through a first valve body. When a predetermined execution condition is satisfied, an ECU reduces power supplied to a coil more than that in a normal control to implement a noise reduction control for reducing an operating noise generated along with the driving of the valve body. During the noise reduction control, a responsiveness parameter indicating responsiveness from starting energization of the coil until the valve body is displaced to a valve closing position is acquired. An energization start timing in the noise reduction control is calculated based on the acquired responsiveness parameter after the parameter is acquired. As a result, a discharge amount control of the high-pressure pump can be appropriately implemented in the noise reduction control.

An internal combustion engine is provided. The internal combustion engine includes a control device, and at least one injector for liquid fuel that includes a discharge opening for the liquid fuel. The at least one injector is connected to a collection volume by means of a line for liquid fuel. Liquid fuel can flow through the line for liquid fuel from the at least one injector to the collection volume. A control element that can be adjusted by the control device via a control signal is also provided. Via the control element, a back pressure in the line for liquid fuel can be adjusted in order to adjust an amount of liquid fuel discharged through the discharge opening of the at least one injector. Also provided is a method for operating an internal combustion engine and an injector.

A fuel injection control device for an internal combustion engine which is applied to a fuel injection system of the internal combustion engine, the fuel injection system including fuel injectors, driving circuits that drive the fuel injectors in each of driving systems into which the fuel injectors are divided, and current detection circuits that are provided to the driving systems, respectively, and the current detection circuits that sense driving currents of corresponding fuel injectors. The fuel injection control device includes an acquisition unit to acquire a current change parameter that is a parameter correlative to a change quantity of a sensed current per unit time in each of the driving systems, and a current correction unit to execute a current correction in at least one of the driving systems based on the current change parameter in each of the driving systems.

The invention relates to a method and a device for actuating an injection valve, which has a piezo actuator and a nozzle needle, of a fuel injection system of an internal combustion engine, in which method a control unit, in a manner dependent on a setpoint stroke height of the piezo actuator in successive injection cycles, outputs a control signal for changing the actual stroke height of the piezo actuator, characterized in that the control unit changes the setpoint stroke height of the piezo actuator, for compensation of the temperature dependency of the capacitance of the piezo actuator, in a manner dependent on the temperature of said piezo actuator.

A nozzle assembly of a fuel injector includes a nozzle body in which a needle member is adapted to translate. The nozzle assembly is further provided with an electrical circuit so that an electrical signal enabling contact detection is measurable between the needle member and the nozzle body. The nozzle assembly also includes a piezoresistive device which continuously varies the electrical signal during the final closing displacements, or the initial opening displacements, of the needle, the variations of the signal being a function of a differential pressure.

A fuel injection control device includes a correction unit to calculate a correction coefficient for correcting a valve closing timing detected by an electromotive force quantity detection mode by using a valve closing timing detected by a timing detection mode. An estimation unit estimates an estimated injection quantity by using a valve closing timing after corrected by using a correction coefficient when the electromotive force quantity detection mode is selected by a selection unit and a valve closing timing is detected by the electromotive force quantity detection mode.

A method for determining an injection quantity of a fuel injector determines a first time at which an injection process of the fuel injector starts, a second time at which the injection process of the fuel injector ends, calculates a model on the basis of the first time and the second time, which model represents the position of a nozzle needle of the fuel injector as a function of the time, and calculates the quantity of fuel to inject.

An ECU opens a valve element to inject fuel in conjunction with energization of a fuel injection valve provided for an engine. The ECU includes an injection control unit, a characteristic acquisition unit, and a fuel injection correction unit. The injection control unit implements a partial-lift injection during which the valve element does not reach a full-lift position to open the fuel injection valve by an energization time. The characteristic acquisition unit acquires an actual lifting behavior of the valve element as an actual lift characteristic when the partial-lift injection is implemented. The fuel injection correction unit compares the actual lift characteristic acquired by the characteristic acquisition unit with a predetermined reference characteristic and corrects a fuel injection quantity in the partial-lift injection based on a result of the comparison.

In a fuel injection valve including a variable lift mechanism of two or more stages, when fuel is injected with a lift different from a command, exhaust emission deterioration and torque fluctuations may occur.

A control device for a fuel injection valve including a variable lift mechanism of two or more stages is provided, which senses a drive lift of the fuel injection valve from an inflection point of a drive current during valve opening operation or a drive voltage during valve closing operation, and limits the command drive lift when the sensed drive lift is different from a command drive lift.

A fuel injection control device first causes a first power supply unit to apply a voltage to a fuel injection valve, subsequently causes a second power supply unit to apply a voltage to the fuel injection valve, and after the first power supply unit applies the voltage, executes a lift position determination process to determine that a valve element of the fuel injection valve reaches a predetermined lift position based on a change in a drive current. A first control unit performs a drive control on the fuel injection valve without executing the lift position determination process. A second control unit executes the lift position determination process and performs a drive control on the fuel injection valve. The second control unit controls the drive current to decrease when the valve element reaches the predetermined lift position compared to a case where the first control unit performs drive control.