Back to results
US 11,480,129 B2Granted
Fuel system and fuel injector control strategy for stabilized injection control valve closing
AssigneeCaterpillar Inc.
InventorAdam Charles Hill
Life of this patent
Estimating the term…
Abstract
A fuel system includes a fuel injector, and a fueling control unit electrically connected to a solenoid actuator in the fuel injector. The fueling control unit is structured to energize and deenergize the solenoid actuator to lift and return an armature coupled with an injection control valve. The fueling control unit also reenergizes the solenoid actuator with an armature retarding current while the armature is in flight to stabilize closing of the injection control valve. The armature retarding current can be used to electronically trim the fuel injector to limit an error in a quantity of injected fuel.
Claims18
A fuel system for an engine comprising:
- a fuel injector having formed therein a high pressure fuel inlet and a control chamber, and defining a low pressure space;
- the fuel injector including an outlet check having a closing hydraulic surface exposed to a fluid pressure of the control chamber, a solenoid actuator, an armature movable in the fuel injector based on energizing and deenergizing the solenoid actuator, and an injection control valve movable in the fuel injector based on the moving of the armature to open and close a fluid connection between the control chamber and the low pressure space;
- the injection control valve is captive between a valve seat and a valve rod coupled to the armature and unattached to the injection control valve;
- and
- a fueling control unit electrically connected to the solenoid actuator and structured to:
- energize the solenoid actuator to lift the armature from a stop position and open the injection control valve to start an injection of fuel from the fuel injector;
- deenergize the solenoid actuator to initiate returning the armature to the stop position;
- reenergize the solenoid actuator with an armature retarding current while the armature is in flight toward the stop position;
- stabilize, by way of the armature retarding current, closing of the injection control valve to end the injection of fuel from the fuel injector;
- monitor a back EMF induced by the armature in an actuator control circuit;
- and
- vary at least one of a dwell time before the armature retarding current or a duration of the armature retarding current based on a timing of a local maximum of the back EMF that is indicative of the armature reaching the stop position.
9 more elements
A fuel control system comprising:
- a fueling control unit including a data processor, and a computer readable memory;
- the computer readable memory storing fueling control instructions for actuating a fuel injector to inject fuel into a combustion cylinder in an engine, and a trim file for limiting an error in a quantity of the injected fuel;
- the data processor is structured by way of executing the fueling control instructions to:
- energize a solenoid actuator in the fuel injector with a pull-in current to lift an armature from a stop position and open an injection control valve to start an injection of fuel from the fuel injector;
- deenergize the solenoid actuator to initiate returning the armature to the stop position;
- reenergize the solenoid actuator with an armature retarding current that is based on the trim file while the armature is in flight toward the stop position;
- and
- stabilize, by way of the armature retarding current, closing of the injection control valve to end the injection of fuel from the fuel injector;
- the data processor is further structured to:
- monitor a back EMF induced by the armature in an actuator control circuit;
- and
- vary at least one of a dwell time before the armature retarding current or a duration of the armature retarding current based on a timing of a local maximum of the back EMF that is indicative of the armature reaching the stop position.
9 more elements
A method of operating a fuel system for an engine comprising:
- energizing a solenoid actuator to lift an armature in a fuel injector from a stop position;
- opening an injection control valve fluidly between a check control chamber and a low pressure space of the fuel injector, based on the lifting of the armature, to start an injection of fuel from the fuel injector;
- deenergizing the solenoid actuator to initiate returning of the armature to the stop position;
- reenergizing the solenoid actuator to retard the armature while in flight toward the stop position;
- stabilizing, based on the retarding of the armature, closing of the injection control valve to end the injection of fuel;
- limiting bouncing the armature against an armature stop based on the retarding of the armature;
- and
- the stabilizing of the closing of the injection control valve includes stabilizing the injection control valve between a valve rod unattached to the injection control valve and a valve seat, based on the limiting of the bouncing of the armature;
- monitoring a back EMF induced by the armature in an actuator control circuit;
- and
- varying at least one of a dwell time before reenergizing the solenoid or a duration of reenergizing the solenoid based on a timing of a local maximum of the back EMF that is indicative of the armature reaching the stop position.
8 more elements
Dependencies are inferred from the claim text.