Patent ID: 6209513
Filing Date: 2001-04-03
Classification: F02D,H01F,H02P

Abstract:
An inductive load driving device which is suitable for driving a same inductive load a plurality of times within a predetermined period of time and for executing that driving repeatedly, wherein said same inductive load is a respective solenoid, of a respective one of solenoid valves in fuel injectors for respective cylinders of an internal combustion engine, which controls a start time and a finish time of fuel injection by the respective one of the solenoid valves; said inductive load driving device comprising:a plurality of step-up circuits, each for alternately storing energy to step up a voltage to a high voltage and then applying the resulting high voltage to a respective same inductive load within a predetermined period of time, to allow a respective resulting load current to rise at high speed;a single holding current output circuit, for applying a predetermined voltage to a respective same inductive load, after the respective resulting load current has been raised responsive to a respective one of said plurality of step-up circuits, to hold the respective resulting load current at a predetermined value;a plurality of switching means, which are switchable in such a manner that a respective output of said plurality of step-up circuits and an output of said single holding current output circuit are alternately connected to a respective same inductive load; anda control logic circuit for switching said plurality of switching means in a predetermined sequence; andwherein said plurality of step-up circuits includes a first step-up circuit and a second step-up circuit;wherein said first step-up circuit and said single holding current output circuit drive solenoids in the fuel injectors corresponding to respective cylinders in the internal combustion engine at times of pilot injection for the respective cylinder;wherein said second step-up circuit and said single holding current output circuit drive, at each respective time of main injection, the same respective solenoid that was driven at a respective time of pilot injection for the respective cylinder;wherein said plurality of switching means execute switching from/to outputs of said first step-up circuit at a time of a pilot injection to/from outputs of said second step-up circuit at a time of a main injection.