Fuel Injection Control Unit Partial Lift Injection Precision
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Solution Overview
Problem
Conventional fuel injection control systems face challenges in achieving precise control of injection amounts during partial lift injection due to variations in coil temperature, leading to inaccuracies in energization time management.
Innovation Solution
A fuel injection control unit that includes a controller, an injection amount detector, and a correction unit, which detects the injection amount and corrects the energization time based on previously detected values, distinguishing between small and extremely small amount regions to prevent precision degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If partial lift injection is implemented to reduce minimum injection amount, then injection amount precision is improved, but injection amount control precision deteriorates due to coil temperature variation
Solution Approach 1:
The patent implements feedback control by detecting the actual injection amount through the injection amount detector and using this detection value to correct the energization time in the correction unit. This closed-loop feedback mechanism compensates for variations caused by coil temperature changes, allowing the system to maintain precise injection amount control while operating in partial lift injection mode.
Solution Approach 2:
The patent dynamically adjusts the energization time parameter based on detected injection amount variations. The correction unit modifies the energization time according to the detection value from the injection amount detector, thereby adapting the control parameters to compensate for coil temperature-induced variations and maintain precise injection control.
2Measurement precision
If energization time correction is applied to extremely small amount region, then injection amount precision is improved, but control stability deteriorates due to amplification of detection errors
Solution Approach 1:
The patent applies different correction strategies to different regions of the injection amount range. For the small amount region, energization time correction is applied to improve precision. For the extremely small amount region, correction is prohibited to maintain stability. This localized differentiation of control behavior allows the system to optimize for precision where appropriate while maintaining stability where correction would be harmful.
Solution Approach 2:
The patent segments the injection amount range into two distinct regions: the small amount region where correction is permitted and the extremely small amount region where correction is prohibited. This segmentation allows the system to apply appropriate control strategies to each region, preventing the amplification of detection errors in the extremely small amount region while still improving precision in the small amount region.
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 solution improves the precision of injection amounts in the small amount region while preventing degradation in the extremely small amount region by adjusting energization times based on detected values, effectively managing variations caused by coil temperature.
Implementation Method 1
a fuel injection valve that injects a fuel used for combustion of an internal combustion engine by opening a valve body due to an electromagnetic attraction force generated by energization of a coil
Data Source
AI summary
A fuel injection control unit includes an injection amount detector and a correction unit. When implementing partial lift injection where a valve closing operation is started after the valve body starts a valve opening operation and before a valve body reaches a maximum valve open position, the injection amount detector detects a physical quantity (valve closing timing) having a correlation with an injection amount. When implementing the partial lift injection, the correction unit corrects an energization time of a fuel injection valve on the basis of a detection value (learning value) that was previously detected by the injection amount detector. An energization time in a small amount region longer than a predetermined time in the partial lift injection is allowed to be corrected on the basis of a value (small amount time detection value) detected in the small amount region by the injection amount detector. On the other hand, an energization time in an extremely small amount region shorter than the predetermined time is prohibited from being corrected on the basis of the above small amount time detection value. As a result, a precision in the injection amount in the partial lift injection is improved.