Injection Valve Rate Determination via Adapter Pressure Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for determining the injection rate of injection valves in internal combustion engines face limitations due to interfering oscillations and delays caused by the adapter volume, leading to inaccurate and low-resolution injection profiles.
Innovation Solution
Incorporating a pressure sensor in the adapter volume to detect and account for pressure changes, in addition to piston travel and temperature, allows for precise calculation of the injection rate by using a mathematical model that corrects for oscillation-induced interference and delays, thereby improving the accuracy of the injection rate determination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the injection rate is determined by differentiating the injection quantity over time, then the injection rate can be calculated, but the measurement signals contain interfering oscillations from spring-mass systems that reduce measurement precision
Solution Approach 1:
A mathematical model acts as an intermediary between the raw piston travel measurements and the final injection rate calculation. This model incorporates damped oscillation characteristics to filter out interfering oscillations from spring-mass systems while preserving the true injection rate signal, thereby resolving the contradiction between obtaining injection rate data and avoiding oscillation interference
Solution Approach 2:
The measurement system incorporates feedback by continuously monitoring piston travel and using this information to update the mathematical model's oscillation parameters. This feedback mechanism allows the system to adapt to changing oscillation conditions and maintain measurement precision despite the presence of interfering oscillations
2Productivity
If the piston travel is used to calculate injection quantity, then the injection rate can be determined, but the dynamic properties of the piston cause oscillations that limit the time resolution of the injection profile
Solution Approach 1:
The patent replaces direct mechanical measurement of injection rate with a mathematical modeling approach. Instead of mechanically measuring flow rate directly (which would be affected by piston oscillations), the system uses piston travel data combined with a mathematical model that accounts for oscillatory behavior, thereby achieving high time resolution without being limited by mechanical measurement constraints
Solution Approach 2:
The mathematical model explicitly incorporates dynamic oscillation characteristics of the piston system. By modeling the piston movement as a combination of useful injection motion and oscillatory components, the system can separate these dynamics and extract the true injection rate profile with high time resolution, resolving the contradiction between calculation speed and measurement precision
3Reliability
If an adapter volume is introduced to connect the injection valve to the measuring chamber, then the connection becomes fluid-tight, but the adapter volume causes delays and damping of the injection signal
Solution Approach 1:
The adapter volume is acknowledged as an intermediary element that inevitably causes signal delays and damping. The mathematical model compensates for these effects by incorporating the adapter volume's dynamic characteristics, allowing the system to maintain both reliable fluid-tight connection and accurate injection rate measurement
Solution Approach 2:
The system changes the measurement approach by monitoring pressure changes in the adapter volume and measuring chamber rather than directly measuring flow rate. This parameter change allows the system to account for the adapter volume's delaying and damping effects, maintaining measurement precision while preserving the fluid-tight connection advantage
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 precise and high-resolution determination of the injection rate, eliminating interference variables and providing reliable results for the optimization of injection valves by accounting for adapter volume dynamics in real-time calculations.
Implementation Method 1
a pressure sensor by means of which the pressure in the adapter volume can be detected during an injection is assigned to the adapter volume
Implementation Method 2
The travel of the piston which is brought about by the injection is detected
Implementation Method 3
the pressure of the test fluid in the measuring chamber is also detected and taken into account during the calculation
Implementation Method 4
the temperature in the measuring chamber, since said temperature also influences the raw density of the test fluid
Data Source
AI summary
The invention relates to a method for determining the injection rate of an injection valve (1) using a mathematical model which is based on measurement values comprising the stroke (x) of a piston (3) that delimits a measurement chamber (2) during the injection of a test fluid (4) into the measurement chamber (2). The injection rate is corrected on the basis of an additional measurement value. According to the invention, the pressure (pa) in an adapter volume (5), via which the injection valve (1) is connected to the measurement chamber (2), is used as an additional measurement value for correcting the injection rate. The invention further relates to a device for determining the injection rate of an injection valve.