Caterpillar Inc.

Mitchell B Juchems

Andrew O Marrack

Daniel Reese Puckett

Kaushik Krishnamurthy

Lifeng Wang

Satya Naga Deepak Pillarisetti

Michael E Sattler

Jeffrey E Ledford

Seth Evans

Pierson Klein

A dual fuel system includes a fuel injector having a fuel pressurization plunger, and a fueling control unit structured to determine a fuel bulk modulus term based upon a volume change value (dV) and a pressure change value (dP) for a fuel pressurized in the fuel injector. The fueling control unit is further structured to determine fuel injector control commands by way of map lookups on fueling maps selected on the basis of the fuel bulk modulus term. Related apparatus and methodology are also disclosed.

Fuel injector control strategy using fuel bulk modulus for fuel injector command determination

In one instance, disclosed herein is a method for controlling a fuel injector of an engine system, the method including: applying a first current to a spill valve solenoid to move a spill valve of the fuel injector to a closed spill position; reducing the first current applied to the spill valve solenoid to move the spill valve to an at least partially-open position; determining a dwell duration for the fuel injector based on an expected fuel pressure of the fuel injector; and after the determined dwell duration, increasing the first current applied to the spill valve solenoid to return the spill valve to the closed spill position.

Pressure control for fuel injectors

In one instance, disclosed herein is a method for controlling a fuel injector of an engine system, the method comprising: determining, based on an engine condition of the engine system, a pull-in duration for the fuel injector during which current is applied to move a valve member away from a resting position; applying a current to a valve solenoid to move the valve member of the fuel injector to a closed position for the determined pull-in duration; and after the determined pull-in duration, reducing the current applied to the valve solenoid to a keep-in level.

Power draw control for fuel injectors

A fuel injector includes a nozzle, and a nozzle check including a closing hydraulic surface. The fuel injector also includes a high pressure passage, a low pressure drain, a control passage, a check control chamber, and a valve seat. A relief passage is formed by at least one of an injector housing or a control valve in a control valve assembly. The control valve is movable among a rest position, a lifted injection position, and a lifted relief position where the high pressure passage connects to the relief passage. The control valve can be operated to selectively connect the high pressure passage to the relief passage to bleed fuel pressure to prevent over-pressurization. Related apparatus and methodology is also disclosed.

Injection control valve in fuel injector configured for pressure relief

An electronically controlled fuel injector includes an injection valve; a control valve fluidly connected between a pressurized fuel supply passage and a control chamber for controlling operation of the injection valve, the control valve movable between a non-injection position and an injection position; the injection valve configured to inject fuel with the control valve in the injection position; and a control member chamber including an orifice that fluidly connects the control member chamber with a low pressure return line of a fuel supply system. The control chamber is fluidly coupled with a pressure communication passage such that the control chamber is fluidly coupled with the low pressure return line through the orifice in the control member chamber when the control valve is in the injection position. The pressure communication passage includes a two-way, variable flow rate valve.

Fuel injector control system and method

Operating a fuel system for an engine includes moving a plunger during a pumping cycle between an advanced position and a retracted position, and pulsing a solenoid actuator in an electrical circuit during at least one off cycle of the plunger where the plunger is neither advancing nor retracting with a plurality of current pulses of varied duration. An electrical property such as a freewheeling response in the electrical circuit induced by moving a valve in response to each respective current pulse is monitored, and a valve timing of the valve determined based on the monitored electrical property. The fuel system including a fuel injector may be electronically trimmed based on the determined valve timing. Related apparatus and control logic is also disclosed.

Valve timing detection in fuel system using off cycle sweep

A fuel injection installation method includes detecting an actuation timing of a first valve of a fuel injector, detecting an actuation timing of a second valve of the fuel injector, detecting a return timing of the first valve of the fuel injector, and detecting a return timing of the second valve of the fuel injector. The method includes, for one or more fuel injection events, modifying at least one of: a maximum amplitude of solenoid current, an average amplitude of solenoid current, a start time of solenoid current, an end time of solenoid current, or a total time of solenoid current. The modification is based on the actuation timing of the first valve, the actuation timing of the second valve, the return timing of the first valve, and the return timing of the second valve, and may be performed for installation of the fuel injector.

Controlling a fuel injector in a fuel system for an engine includes switching between a boosted voltage power supply and a lower voltage power supply during energizing a solenoid actuator in a fuel injector, and generating a solenoid energizing waveform including a pull-in tier produced by a boosted voltage incipient current, a boosted voltage second current, and a lower voltage later current, based on the switching between a boosted voltage power supply and a lower voltage power supply. Controlling a fuel injector further includes detecting an arrival timing of the valve based on a property of the lower voltage later current, and electronically trimming the fuel injector based on the detecting an arrival timing. Related control system logic is also disclosed.

Optimized energy waveform for fuel injector trimming based on valve arrival time

A fuel injection system includes a fuel injector, the fuel injector having an injection control valve, a solenoid that, when energized, is configured to modify a position of the injection control valve, and a controller. The controller is configured to generate a command for energizing the solenoid, identify variability in one or more injection events, and based on the identified variability, increase an amount of energy supplied to the solenoid.

Fuel injector variability reduction

Operating an engine system and fuel system includes energizing a solenoid actuator for a spill valve in a fuel injector in a first engine cycle via a standard waveform to inject a shot of fuel. Operating an engine system and fuel system further includes determining suitability for reduced energy operating of the fuel system, and energizing the solenoid actuator via a reduced energy waveform based on the determining suitability so as to inject one or more shots of fuel in a second engine cycle. The operating methodology and control logic can extend an engine speed range for multi-shot fuel injection in an engine.

Reduced energy waveform for energizing solenoid actuator in fuel injector valve

A method for controlling a fuel injector of an engine system includes applying a pull-in current to close a spill valve of the fuel injector and detecting a timing at which the spill valve closes. The method also includes adjusting at least one of an amplitude of the pull-in current, a duration of the pull-in current, or a timing of a start of an application of the pull-in current based on the detected timing of the closing of the spill valve.

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Tremont, IL, United States of America

Mitchell B Juchems