Disclosed is a method for determining a static flow rate of a piezo-electric injector of an injection system. The piezo-electric injector includes a needle and a piezo-electric actuator designed to control a valve of the injector. The injection system includes an electric generator designed to send electric current pulses to the piezo-electric actuator of the injector, and a voltage sensor designed to measure voltage values at the terminals of the piezo-electric actuator. The method includes the following steps: sending during a phase of closure of the needle of an electric current pulse such that the piezo-electric actuator is positioned in contact with the valve, without giving rise to the opening thereof; measurement of a plurality of voltage values of the piezo-electric actuator; and determining a static flow rate of the piezo-electric injector on the basis of a plurality of voltage values measured of the piezo-electric actuator.

Provided is a load drive device for controlling a fuel injection device for a vehicle engine and capable of checking an operation of the fuel injection device with high reliability without actually injecting fuel before starting the engine. The load drive device includes: a first switching element that is connected to a high-side of a load; a second switching element that is connected to a low-side of the load; a pre-driver circuit that transmits a drive instruction to the first switching element and the second switching element; and an arithmetic device that transmits a control instruction to the pre-driver circuit, in which a first monitor line and the second monitor line are connected to the arithmetic device, the first monitor line monitoring the drive instruction from the pre-driver circuit to the first switching element before starting an engine, and the second monitor line monitoring the drive instruction from the pre-driver circuit to the second switching element, and the pre-driver circuit has a first control mode in which the first switching element is turned off and the drive instruction is transmitted to the second switching element, and a second control mode in which the second switching element is turned off and the drive instruction is transmitted to the first switching element.

An injection control device opens and closes a fuel injection valve by driving the fuel injection valve with a current to control fuel injection to an internal combustion engine. The injection control device includes: a booster circuit that boosts a battery voltage; a boosting control unit that performs boosting control on the booster circuit; and a charge control setting unit that sets charge permission or charge prohibition for the booster circuit to the boosting control unit.

Controlling a fuel injector in a fuel system for an engine includes switching between a boosted voltage power supply and a lower voltage power supply during energizing a solenoid actuator in a fuel injector, and generating a solenoid energizing waveform including a pull-in tier produced by a boosted voltage incipient current, a boosted voltage second current, and a lower voltage later current, based on the switching between a boosted voltage power supply and a lower voltage power supply. Controlling a fuel injector further includes detecting an arrival timing of the valve based on a property of the lower voltage later current, and electronically trimming the fuel injector based on the detecting an arrival timing. Related control system logic is also disclosed.

Method to determine a closing instant of an electromagnetic fuel injector; in a beginning instant of the injection, a positive voltage is applied to a coil of an electromagnetic actuator so as to cause an electric current to circulate through the coil, said electric current determining the opening of an injection valve; in an end instant of the injection, a negative voltage is applied to the coil of the electromagnetic actuator so as to cancel the electric current circulating through the coil; a first voltage time development is detected at least one end of the coil of the electromagnetic actuator after the cancellation of the electric current circulating through the coil; the voltage actuation time development is compared with a voltage comparison time development; and the closing instant of the electromagnetic injector is determined based on the comparison between the voltage actuation time development and the voltage comparison time development.

Method to determine an opening time of an electromagnetic fuel injector; the electromagnetic fuel injector is controlled using a series of progressively increasing energization times of the electromagnetic actuator; for each control of the electromagnetic injector, the presence or the absence of a closing of the injection valve is detected; the opening time is identified, which is equal to an intermediate value between the last energization time of the electromagnetic actuator for which the absence of a closing of the injection valve was determined and the first energization time of the electromagnetic actuator for which the presence of a closing of the injection valve was determined.

Provided is a control device of a fuel injection device which can stabilize a behavior of a valve even when a voltage of a voltage source varies, and can reduce a deviation of an injection amount. The fuel injection device includes a valve and a coil which generates a magnetic attraction force to attract a movable element which drives the valve. A control device applies a predetermined voltage to the coil on the basis of an injection pulse, causes a drive current to flow to the coil until the drive current reaches a maximum current, drives the valve by attracting the movable element, and injects fuel. The drive current flowing to the coil is lowered from the maximum current before the valve reaches a desired maximum lift position, and a constant voltage lower than a predetermined voltage or 0 V is continuously applied to the coil until the valve reaches the desired maximum lift position.

A method for determining a time at which a fuel injector, for an internal combustion engine of a motor vehicle, is in a predetermined opening state comprises applying a predetermined electrical voltage profile to the solenoid drive, detecting the temporal profile of the current strength of a current flowing through the coil of the solenoid drive, detecting the temporal profile of the voltage across the coil, determining a function based on the temporal profile of the current strength and the temporal profile of the voltage, wherein the function represents the interlinked magnetic flux or a temporal derivative of the interlinked magnetic flux in the solenoid drive, and determining the time as the time at which the function has a characteristic feature.

A control device according to an embodiment includes a storage, a determining unit, and a driving unit. The storage stores therein information on a hysteresis area of an actuator. The determining unit determines, based on a control mode, a target current value according to the hysteresis area whose information is stored in the storage. The driving unit supplies a driving current according to the target current value determined by the determining unit to the actuator.

An injection control device controls a drive of a solenoid in a high pressure pump for pressurizing fuel to an internal combustion engine. The injection control device includes a transistor on an upstream side of a power supply path from a direct current power supply line to the solenoid and a transistor provided on a downstream side of the power supply path. The injection control device further includes a diode at a position between an upstream terminal of the solenoid and ground, a transistor arranged in parallel with the diode, and a drive controller. The drive controller drives the solenoid to an open position by switching ON the transistors on the upstream and downstream sides of the power supply path.