Inductive load driving device and driving method

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 the 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 into a respective cylinder of said internal combustion engine, 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;
• and
• a control logic circuit for switching said plurality of switching means in a predetermined sequence;
• and
• wherein 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 a first solenoid in a fuel injector corresponding to a first cylinder in the internal combustion engine at a time of pilot injection for said first cylinder, and drive a second solenoid corresponding to a second cylinder, which injects fuel next after said first cylinder, at a time of main injection for said second cylinder, and those drivings at a time of a pilot injection and at a time of a main injection are repeated for other combinations of cylinders;
• wherein said second step-up circuit and said single holding current output circuit drive the first solenoid, corresponding to said first cylinder, at a time of main injection for said first cylinder, and drive the second solenoid, corresponding to the second cylinder which injects fuel next after said first cylinder, at a time of pilot injection for said second cylinder, and those drivings at the time of a main injection and at a time of pilot injection are repeated for other combinations of cylinders;
• and
• wherein said plurality of switching means executes switching from/to outputs of said first step-up circuit and said single holding current output circuit, at a time of pilot injection, to/from outputs of said second step-up circuit and said single holding current output circuit, at a time of main injection, or executes switching from/to outputs of said first step-up circuit and said single holding current output circuit, at a time of main injection, to/from outputs of said second step-up circuit and said single holding current output circuit, at a time of pilot injection.

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 the driving repeatedly, wherein said same inductive load is a respective one of a plurality of phase coils in a step motor, 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 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 holding current output circuit are alternately connected to a respective same inductive load;
• and
• a level variation circuit for switching said plurality of switching means.

An inductive load driving device which is suitable for driving same inductive load a plurality of times within a predetermined period of time and for executing the driving repeatedly, 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 rise to a 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;
• and
• a control circuit for switching said plurality of switching means in a predetermined sequence.