초록 ▼

The present invention is a fuel injection system having one or more fuel injectors and an electronic control system therefore. The preferred fuel injector has a double magnetic latching solenoid three-way or four-way spool valve that controls the flow of a working fluid that is used to control the d

The present invention is a fuel injection system having one or more fuel injectors and an electronic control system therefore. The preferred fuel injector has a double magnetic latching solenoid three-way or four-way spool valve that controls the flow of a working fluid that is used to control the discharge of fuel into the combustion chamber or intake manifold of an engine through the nozzle of the injector. The control system provides actuating current pulses to each of the solenoids to actuate and latch the solenoids to effect initiation and termination of the injection. Disclosed are control systems that provide a snap action in one or both actuating directions of the valve by electromagnetically retaining the valve in the latched condition until the force in the actuated solenoid builds to a high level, and then releasing the valve for higher acceleration to the actuated position. Also disclosed is an exemplary control system that senses the arrival of valve at the actuated position so that the actuating current pulse can be terminated as soon as possible so as to allow a strong current pulse drive, but of low total energy, for fast actuation of a relatively small valve. Other embodiments, features and uses of the invention are disclosed.

대표청구항 ▼

[ We claim:] [1.] A fuel injection system comprising:a fuel injector;an injector valve member for coupling to a source of fluid under pressure, the injector valve member being coupled to the fuel injector;a first solenoid coil for magnetically moving the valve member to a first position for causing

[ We claim:] [1.] A fuel injection system comprising:a fuel injector;an injector valve member for coupling to a source of fluid under pressure, the injector valve member being coupled to the fuel injector;a first solenoid coil for magnetically moving the valve member to a first position for causing fuel injection by the fuel injector responsive to an actuating current in the first solenoid coil;a second solenoid coil for moving the valve member to a second position for stopping fuel injection by the fuel injector responsive to an actuating current in the second solenoid coil;an electronic control system coupled to the first and second solenoid coils for providing current to the first and second solenoid coils to initiate fuel injection and to terminate fuel injection shortly thereafter to provide a pilot injection cycle, and for providing current to the first and second solenoid coils to initiate main fuel injection a short time after the pilot injection and to terminate main fuel injection, the control system including a sensing circuit coupled to one of the first and second solenoid coils and responsive to the back EMF on the solenoid coil for sensing the valve member reaching the position caused by the current in the other solenoid coil and for terminating the current in said other solenoid coil responsive thereto.