Fuel system for retarded armature lifting speed and fuel system operating method
AssigneeCaterpillar Inc.
InventorsAdam Charles Hill, Zhenyu Li
Life of this patent
Estimating the term…
Abstract
A fuel system for an internal combustion engine includes a fuel injector, and a fueling control unit electrically connected to a solenoid in the fuel injector. The fueling control unit energizes the solenoid with a lift current pulse to lift an armature, then energizes the solenoid with a separate capture current pulse to capture the armature at a lifted position. The solenoid is deenergized a dwell time while the armature is in flight toward the lifted position. Armature lifting speed is retarded based on the deenergizing of the solenoid so as to limit bouncing of a valve pin in the fuel injector against a stop. The techniques assist in linearizing a fuel delivery curve.
Claims20
A fuel system for an engine comprising:
- a fuel injector including an outlet check having a closing hydraulic surface exposed to a fluid pressure of a control chamber formed in the fuel injector, a stop, and an injection control valve assembly including a solenoid, an armature, and a valve pin coupled to the armature;
- and
- a fueling control unit electrically connected to the solenoid and structured to:
- energize the solenoid with a lift current pulse to lift the armature;
- energize the solenoid with a capture current pulse to capture the armature at a lifted position;
- deenergize the solenoid a dwell time, prior to the energizing the solenoid with the capture current pulse, while the armature is in flight based on the energizing the solenoid with the lift current pulse toward the lifted position;
- and
- retard the armature based on the deenergizing of the solenoid a dwell time to limit bouncing of the valve pin against the stop.
A method of operating a fuel system for an internal combustion engine comprising:
- energizing a solenoid with a lift current pulse to lift an armature coupled to an injection control valve in a fuel injector from a rest position to a lifted position;
- opening the injection control valve based on the lifting of the armature to start an injection of fuel from the fuel injector using a directly controlled outlet check;
- energizing the solenoid with a capture current pulse occurring a dwell time after the lift current pulse to capture the armature at the lifted position;
- returning the armature to the rest position;
- and
- closing the injection control valve based on the returning of the armature to the rest position to end an injection of fuel using the directly controlled outlet check.
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;
- the data processor is structured by way of executing the fueling control instructions to:
- energize a solenoid in the fuel injector with a lift current pulse to lift an armature coupled to a valve pin in an injection control valve assembly;
- energize the solenoid with a capture current pulse to capture the armature at a lifted position;
- deenergize the solenoid for a dwell time, prior to the energizing the solenoid with the capture current pulse, while the armature is in flight based on the energizing the solenoid with the lift current pulse from the rest position toward the lifted position;
- and
- retard a lifting speed of the armature based on the deenergizing of the solenoid for a dwell time so as to limit bouncing the valve pin against a stop in the fuel injector.
Dependencies are inferred from the claim text.