Direct Fuel Injector Transition Region Variability Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Solenoid-controlled direct fuel injectors exhibit unpredictable flow characteristics in the transition region between the ballistic and full lift regions, leading to variability in fuel injection, which causes torque imbalances, increased emissions, and reduced fuel economy due to non-linear behavior that is difficult to compensate for.
Innovation Solution
The method involves delivering fuel as multiple direct injections and adjusting the ratio and number of injections to move the fuel mass out of the transition region by modifying the fuel mass and split ratio based on the injector's operating regions, allowing the engine controller to update the injection profile to operate outside the transition region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the direct fuel injector operates in the transition region between ballistic and full lift regions, then the injector can deliver fuel across a wide range of pulse-widths, but the flow rate becomes inaccurate and unpredictable causing shot-to-shot and part-to-part variability
Solution Approach 1:
The patent segments the fuel injection operation into distinct regions: ballistic region (smaller pulse-widths) and full lift region (larger pulse-widths), avoiding the problematic transition region. By dividing the operating range and assigning different injection strategies to each region, the system achieves both wide adaptability and precise fuel metering without relying on the unpredictable transition region.
2Quantity of substance
If the injector pulse-width is increased in the transition region, then more fuel mass can be delivered, but the variability is exacerbated due to non-linear slope changes that are different for each injector and shot-to-shot
Solution Approach 1:
The patent implements dynamic region identification that adapts to each injector's actual characteristics through learning. The system dynamically determines whether an injector is operating in the ballistic or full lift region based on real-time feedback, allowing the control strategy to adjust accordingly. This dynamic adaptation enables reliable fuel metering across varying conditions without being constrained by fixed pulse-width limits, achieving both high fuel mass delivery and low variability.
3Productivity
If the direct fuel injector is used to improve mixture preparation and reduce cylinder charge temperatures, then engine performance is improved, but NVH, drivability, and emissions requirements cannot be met in certain operating regions due to injector variability
Solution Approach 1:
The patent employs feedback mechanisms where the actual fuel delivery is monitored and compared against target values. The system learns each injector's characteristics through continuous operation and uses this learned information to compensate for variations. This feedback loop enables the engine to maintain optimal performance while meeting NVH, drivability, and emissions requirements by dynamically adjusting injection parameters based on actual injector behavior rather than relying on theoretical models.
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 direct injector variability, improves engine drivability, and decreases emissions by maintaining accurate fuel metering and air-fuel ratios, ensuring the engine operates within more predictable and efficient regions.
Implementation Method 1
solenoid-controlled direct fuel injectors
Data Source
AI summary
Methods and systems are provided for reducing direct injector fueling errors due to injection variability in a transition region of a direct injector map. Fuel injection, including usage of one or more direct and port injected fuel pulses, may be planned based on engine operating conditions including engine temperature and driver demand. Responsive to any of the direct injected fuel pulses having a pulse-width that lies in a high variability transition region of the direct injector, the fuel injection may be adjusted via adjustments to a number and/or split ratio of the injections so as to not operate in the transition region.