Electromagnetic fuel injector and control method thereof

摘要

An electromagnetic fuel injection valve in an engine injects fuel by opening/closing a fuel flowing path with a valve element. A controller controls opening/closing of the fuel flowing path and changes magnetic force generated by a control coil driving the valve element so that the magnetic force is less during a valve open state-holding period than at an initial valve-opening time. The controller detects the voltage of a battery and applies the voltage fed from the battery to the control coil, while changing a time interval (Tc), for which current is passed through the control coil, based on the detected voltage, in order to change the magnetic force, without raising the voltage from the battery. The controller also detects increase/decrease of a pressing force on the valve element caused by fuel pressure and changes the time interval (Tc) accordingly.