Common-Rail Injector Pressure Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Common rail injectors experience variations in injection behavior due to component tolerances, wear, and fuel properties, requiring precise compensation to maintain consistent performance.
Innovation Solution
A method involving a sensor, such as a piezo element, to detect pressure changes and filter oscillations in the signal, allowing for adjustment of operating variables like valve durations and times to compensate for injector and fuel properties, thereby stabilizing injection behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If component tolerances and wear are present in common rail injectors, then manufacturing and operation become easier, but injection behavior varies and consistency deteriorates
Solution Approach 1:
The patent employs feedback control by continuously monitoring pressure in the valve chamber and using this information to adjust operating variables. The method detects pressure changes during valve opening and closing events, evaluates these signals to determine actual injector properties, and compensates for deviations from nominal behavior by adjusting subsequent injection events, thereby maintaining consistent injection performance despite component variations
Solution Approach 2:
The patent changes operating parameters dynamically based on detected injector state. It adjusts opening duration, closing duration, opening time, and closing time of the switching valve and needle valve based on evaluated injector properties such as coking degree, valve bounce, and wear. This parameter adaptation compensates for component tolerances and wear to maintain reliable injection behavior
2Adaptability or versatility
If different fuel properties are used, then fuel versatility increases, but injector behavior varies and requires compensation
Solution Approach 1:
The system uses feedback from pressure sensor signals to detect changes in fuel properties affecting injector operation. By monitoring pressure during valve events and evaluating deviations from expected behavior, the system identifies fuel-property-induced variations and compensates by adjusting operating variables, maintaining consistent injection across different fuel types
Solution Approach 2:
The patent adjusts operating parameters including opening and closing durations and timing of valves based on detected fuel property effects. This dynamic parameter modification compensates for variations caused by different fuel types and temperatures, ensuring reliable injection behavior across diverse fuel conditions
3Device complexity
If pressure sensor signals with oscillations are used directly, then measurement simplicity is maintained, but signal evaluation accuracy deteriorates
Solution Approach 1:
The patent extracts the oscillation component from the pressure sensor signal through filtering before evaluation. By removing the oscillatory portion that complicates analysis while retaining the underlying pressure change information, the system achieves accurate detection of operating events without requiring complex unfiltered signal processing
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 effectively compensates for injector-dependent and fuel-related variations, ensuring consistent injection behavior by determining key properties like coking, valve wear, and fuel viscosity, allowing for precise control of the common rail injector.
Implementation Method 1
The sensor is in particular a piezo element arranged in the low-pressure area of the common rail injector. In this case, the signal can be a voltage applied to the piezo element.
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a method for regulating a common-rail injector. Said method encompasses the detection of a signal (S) from a sensor, which signal is proportional to a pressure in a valve chamber of the common-rail injector, the evaluation of a change in the signal (S) over time (t) in order to detect at least one operation event of the common-rail injector, and the variation of at least one operating variable of the common-rail injector in a manner dependent on the at least one operation event, wherein the at least one operating variable is selected from an opening duration, a closing duration, an opening time and a closing time of a switching valve of the common-rail injector, and from an opening duration, an opening time and a closing time of a needle valve of the common-rail injector.