An injector driver module includes: a first node that is connected to a first terminal of a fuel injector; a first switch configured to, when closed, connect a first potential of a battery to the first node; a second switch configured to, when closed, connect a second potential that is greater than the first potential to the first node; a second node that is connected to a second terminal of the fuel injector; and a third switch configured to, when closed, connect a ground potential to the second node. A switch control module is configured to, starting at a target injecting timing for a fuel injection event of the fuel injector: maintain the third switch closed; and switch the second switch using a pulse width modulated (PWM) signal having (i) a duty cycle that is less than 100 percent and (ii) a predetermined frequency.

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.

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.

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 between an upstream terminal of the solenoid and ground. 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 one of the transistors on the upstream side power supply paths.

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.

A fuel injection control system is usable with an engine, e.g., a diesel engine of a mild hybrid electric vehicle. The control system includes an auxiliary battery, a high-voltage (HV) battery, e.g., 48 VDC, a switching circuit with first and second switching pairs, a controller, and a fuel injector system. The controller opens and closes the switches to command an electrical current from the auxiliary or HV battery according to a predetermined injector current profile. The fuel injector system has one or more control solenoids. Windings of the solenoids are electrically connectable to the HV battery during a boost phase of the profile via opening of the first switching pair and closing of the second switching pair, and to the auxiliary battery during peak, by-pass, hold, and end-of-injection phases of the profile via closing of the first switching pair and opening of the second switching pair.

An internal-combustion-engine fuel injection control device which can accurately control a boosted voltage applied to a fuel injection valve during fuel injection and can control a variation in a fuel injection amount without increasing a size or a cost of the fuel injection control device even when a width of a fuel injection driving pulse to drive the fuel injection valve is small is provided. A fuel injection control device includes a boosting operation control unit configured to start a boosting operation at predetermined timing regardless of an amount of a detected voltage when the detected voltage is higher than a threshold voltage for starting boosting and is lower than a threshold voltage for stopping boosting.

Various embodiments include a method for controlling a pressure dissipation valve comprising a closure element, a spring applying a spring force urging the closure element toward the closed position, and an electromagnetic actuator responding to an applied voltage to urge the closure element to an open position. The method may include: applying a constant voltage until the closure element begins motion counter to the spring force; immediately ending the voltage upon the beginning of motion; thereafter, applying a pulsed voltage to the actuator to induce a substantially constant holding-open current intensity; maintaining the pulsed voltage for a predetermined duration to hold the closure element open; and interrupting the application of voltage after the predetermined duration, wherein the closure element moves into the closed position as a result of the spring force.

In a drive unit of a fuel injection device, an electric current is supplied to the fuel injection device by applying a high voltage to the fuel injection device from a high voltage source whose voltage is boosted to a voltage higher than a battery voltage at the time of opening a valve of the fuel injection device. Thereafter, the electric current supplied to the fuel injection device is lowered to a current value at which a valve element cannot be held in a valve open state by stopping the applying of the high voltage from the high voltage source. Thereafter, in a stage where a supply current is switched to a hold current, another high voltage is applied to the fuel injection device from the high voltage source.

An injector driver module includes: a first node that is connected to a first terminal of a fuel injector; a first switch configured to, when closed, connect a first potential of a battery to the first node; a second switch configured to, when closed, connect a second potential that is greater than the first potential to the first node; a second node that is connected to a second terminal of the fuel injector; and a third switch configured to, when closed, connect a ground potential to the second node. A switch control module is configured to, starting at a target injecting timing for a fuel injection event of the fuel injector: maintain the third switch closed; and switch the second switch using a pulse width modulated (PWM) signal having (i) a duty cycle that is less than 100 percent and (ii) a predetermined frequency.