Solenoid Valve Stroke Determination via Magnetic Flux
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Solution Overview
Problem
Existing methods for determining the stroke of a magnetic valve in fuel injection systems lack reliability and accuracy, leading to uncontrolled changes in injection quantity and timing profile due to variations in idle and working strokes over the service life of the injector.
Innovation Solution
A method and device that utilize reference data sets of coil current and magnetic flux to determine the magnitude of idle and working strokes, allowing for precise actuation of the magnetic valve to maintain desired injection characteristics, involving the generation of a magnetic field, measurement of magnetic flux, and calculation of stroke magnitude based on these data sets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical setting and measurement of idle stroke and working stroke are performed during assembly, then initial stroke values are established, but stroke values vary uncontrolled over service life due to wear and settling
Solution Approach 1:
The patent replaces mechanical stroke measurement and setting methods with an electrical measurement system that uses coil voltage, current, and inductance characteristics to determine armature stroke position. This electrical field-based approach allows for non-contact, repeatable measurements that are not affected by mechanical wear or settling of measurement components.
Solution Approach 2:
The patent implements a feedback system where stroke values determined during operation are used to detect deviations from target injection quantities. The system continuously monitors stroke changes and can trigger alerts or adjustments to maintain injection precision throughout the service life, creating a closed-loop control mechanism.
2Reliability
If stroke values are not monitored during service life, then device complexity remains low, but injection quantity and timing profile become uncontrolled and unreliable
Solution Approach 1:
The patent enables the magnetic valve to self-diagnose its stroke conditions by using its own operational electrical characteristics (voltage, current, inductance) to determine armature position. The system uses existing sensors and processors already present in modern fuel injection systems, adding minimal external components while achieving stroke monitoring and injection quantity control.
Solution Approach 2:
The patent monitors changes in electrical parameters (voltage, current, inductance) that correlate with stroke variations. By tracking these parameter changes over time, the system can detect wear, settling, or other degradation mechanisms affecting stroke consistency without requiring direct mechanical measurement components.
3Manufacturing precision
If electrical actuation parameters are adjusted to compensate for stroke changes, then injection precision is maintained, but actuation complexity increases
Solution Approach 1:
The patent implements dynamic adjustment of actuation parameters based on real-time stroke measurements. The control system modifies voltage, current, or pulse duration parameters adaptively to compensate for detected stroke variations, maintaining precise injection quantities despite changes in armature travel distance or speed characteristics.
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 enables reliable and accurate determination of stroke changes, ensuring consistent injection quantity and timing profile by adjusting the actuation parameters based on determined stroke values, thereby improving the precision and reliability of fuel injection.
Implementation Method 1
A magnetic valve or a solenoid injector may be used for injecting fuel into a combustion chamber, such as a cylinder. A solenoid injector of said type (also referred to as coil-type injector) has a coil which generates a magnetic field when current flows through the coil, whereby a magnetic force is exerted on an armature
Implementation Method 2
If current continues to flow through the coil, the armature and nozzle needle or closure element move further until the armature arrives at and abuts against the pole piece. The distance between the abutment of the armature against a driver of the closure element or of the nozzle needle and the abutment of the armature against the pole piece is also referred to as needle stroke or working stroke. To close the valve, the excitation voltage applied to the coil is deactivated, and the coil is short-circuited, such that the magnetic force is dissipated. The short-circuiting of the coil results in a polarity reversal of the voltage owing to the dissipation of the magnetic field stored in the coil.
Data Source
AI summary
A device and a method are provided for determining a stroke of an armature of a magnetic valve which has a coil and the armature is displaceable by magnetic force, including: providing at least one reference data set which includes a magnitude of a current through the coil and a magnitude of the magnetic flux in the case of a known magnitude of the stroke; generating a current flow through the coil of the magnetic valve in order to generate a magnetic field for generating a magnetic force on the armature, which magnetic force displaces the armature in the direction for the opening of a closure element coupled to the armature; determining a magnitude of the magnetic flux when the armature abuts against a driver of the closure element; and determining the magnitude of the stroke based upon the determined magnitude of the magnetic flux and the reference data set.