Fuel Injector Needle Stroke Correction for Injection Precision
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Solution Overview
Problem
Existing methods for determining the time at which a fuel injector with a solenoid drive is in a predetermined opening state are inaccurate due to variations in the needle stroke caused by wear or running-in processes, leading to inconsistent injection quantities.
Innovation Solution
A method that determines a first time by analyzing a data set representing the relationship between magnetic flux and current intensity, calculating the stroke value, and using this to correct the second time based on a reference stroke value, allowing precise determination of the fuel injector's opening state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed correlation between OPP2 and OPP1 is assumed for indirect determination, then the determination method is simple, but the measurement precision deteriorates due to needle stroke variations
Solution Approach 1:
The patent uses feedback by continuously monitoring the actual needle stroke value and using it to correct the indirect determination of OPP1 time. The control unit adjusts the determination based on the measured deviation from the reference needle stroke value, creating a closed-loop system that maintains precision despite wear and running-in processes.
Solution Approach 2:
The patent changes the parameter used for determination from a fixed correlation to a dynamic correlation based on the actual needle stroke value. By using the measured needle stroke value to calculate the corrected OPP1 time, the system adapts to changing physical conditions while maintaining determination precision.
2Duration of action of stationary object
If the needle stroke varies due to wear or running-in processes, then the injector service life increases, but the injection quantity consistency deteriorates
Solution Approach 1:
The system continuously monitors the needle stroke value and feeds this information back to the control unit, which then corrects the OPP1 time determination. This feedback mechanism ensures that injection quantity consistency is maintained throughout the injector's service life, compensating for wear and running-in effects.
Solution Approach 2:
The system performs self-correction by using its own measurements of needle stroke variation to adjust its determination of OPP1 time. The control unit automatically compensates for changes in needle stroke without external intervention, maintaining reliable injection quantities throughout the injector's operational life.
3Device complexity
If indirect determination based on fixed correlation is used, then the device complexity is low, but the reliability of injection control deteriorates
Solution Approach 1:
The patent implements feedback by measuring the actual needle stroke value and using it to correct the indirect determination of OPP1 time. This feedback loop significantly improves injection control reliability while adding only minimal complexity to the determination system.
Solution Approach 2:
The patent replaces the purely mechanical fixed-correlation method with an electromechanical system that uses electrical measurements (coil voltage, coil current) to determine needle stroke value, which then corrects the time determination. This substitution improves reliability while keeping the overall system complexity manageable.
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 method enables accurate and reliable actuation of the fuel injector, ensuring precise injection quantities by accounting for changes in the needle stroke, thereby improving control over the injection process.
Implementation Method 1
A solenoid injector (also called a coil injector) of this kind has a coil which generates a magnetic field when current flows through the coil, as a result of which a magnetic force is exerted on an armature so that the armature moves
Data Source
AI summary
A method for determining a first time at which a fuel injector having a solenoid drive is in a first predetermined opening state. The method includes the following: (a) determining a second time at which the fuel injector is in a second predetermined state, (b) determining a stroke value of a moving component of the fuel injector, which stroke value corresponds to a movement path of the moving component which is covered when the fuel injector transitions between the first predetermined opening state and the second predetermined opening state, and (c) determining the first time at which the fuel injector is in the first predetermined opening state, on the basis of the second time and the stroke value. A method for actuating a fuel injector having a solenoid drive, an engine controller and a computer program.