Fuel Injector Spill Valve Detection via Solenoid Timing
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Solution Overview
Problem
Internal combustion engines with closely positioned solenoids in fuel injectors experience noise and cross-talk, impairing the accurate detection of valve movement during short injection events, which affects the engine's control unit's ability to monitor and control fuel injection effectively.
Innovation Solution
A fuel injection system that applies a spill valve current to close the spill valve and a control valve current to move the control valve to an injection position, while discontinuing the spill valve current to open the spill valve and delaying the return of the control valve to its non-injection position, using a free-wheeling mode to prevent premature closure and enhance detection accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If solenoids are positioned in close proximity to satisfy size constraints, then the injector size is reduced, but noise and cross-talk are introduced that impair valve movement detection accuracy
Solution Approach 1:
The system performs preliminary actions by de-energizing the control valve solenoid before the spill valve returns to its open position. This timing arrangement ensures that the control valve solenoid is already non-operational when the spill valve moves, eliminating cross-talk interference and enabling accurate detection of the spill valve's movement without the need to physically separate the solenoids.
2Speed
If the control valve solenoid is de-energized rapidly, then the valve returns to non-injection position quickly, but detection of spill valve movement during short injection events is impaired due to cross-talk
Solution Approach 1:
The control valve solenoid is de-energized in advance before the spill valve completes its return motion. This preliminary de-energization maintains fast valve response while eliminating the cross-talk that would occur during rapid de-energization, allowing accurate detection of spill valve movement even during short injection events.
Solution Approach 2:
The system dynamically adjusts the de-energization timing of the control valve solenoid based on the injection event duration and spill valve motion characteristics. This dynamic timing optimization ensures that de-energization occurs at the optimal moment to both maintain fast response and eliminate cross-talk interference for detection.
3Productivity
If the spill valve current is discontinued to open the spill valve, then fuel injection can be controlled, but the control valve may return to non-injection position prematurely due to spring force, affecting detection accuracy
Solution Approach 1:
The control valve solenoid is de-energized preliminarily before the spill valve opens, which prevents the control valve from returning to its non-injection position due to spring force. This timing arrangement maintains the control valve in its injection position throughout the spill valve's motion, enabling accurate detection of spill valve movement while maintaining fuel injection control capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach reduces noise interference and improves the accuracy of valve movement detection, allowing for more precise control of fuel injection timing and quantity, enhancing engine performance and reducing undesirable emissions.
Implementation Method 1
A spill valve solenoid may be positioned within the fuel injector to facilitate movement of the spill valve member between an open and closed position
Implementation Method 2
A control valve solenoid may be positioned within the fuel injector to facilitate movement of the control valve member between a first and second position
Implementation Method 3
The control unit may detect movement of a valve member based on induced current generated in the solenoid (e.g., free-wheeling current induced by movement of a valve member returning to a resting position)
Data Source
AI summary
A method of injecting fuel with a fuel injector includes applying a spill valve current to close a spill valve and applying a control valve current to move a control valve to an injection position. The method also includes discontinuing the application of the spill valve current to open the spill valve and preventing a return of the control valve to a non-injection position while detecting a timing when the spill valve opens.