Injector Closing Time Correction for Fuel Flow Deviation
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Solution Overview
Problem
Existing methods fail to accurately compensate for injector closing time deviations in internal combustion engines, particularly in small flow sections, leading to inconsistent fuel supply across cylinders, due to sensing challenges and manufacturing tolerances.
Innovation Solution
A method that senses injector closing time, determines compensation amounts based on sensing failures and learned characteristic curves, and adjusts injection times to correct deviations, even in small flow sections, by extrapolating sensing values and adjusting multiple injection modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sensing methods are used to detect injector closing time, then measurement is possible in large flow sections, but measurement fails in small flow sections due to inability to detect point of inflection
Solution Approach 1:
The patent uses an intermediary parameter (injection current or voltage) to indirectly detect the injector closing time. Instead of directly measuring the mechanical closing event which produces ambiguous signals in small flow sections, the method measures the electrical parameter that correlates with the closing event, providing a reliable indirect measurement method that works across all flow conditions.
Solution Approach 2:
The patent replaces mechanical sensing methods (which rely on detecting physical movement and point of inflection) with electrical sensing methods (measuring current or voltage changes). This substitution eliminates the limitation of mechanical detection in small flow sections where the mechanical signal is too weak or ambiguous to detect the closing event accurately.
2Ease of operation
If same injection time is commanded to all cylinders, then control simplicity is maintained, but fuel supply consistency deteriorates due to injector characteristic deviations
Solution Approach 1:
The patent changes the injection time parameter for each cylinder based on its specific injector characteristics. By measuring the actual closing time of each injector and calculating a compensation value, the system adjusts the injection time parameter individually for each cylinder, transforming a uniform control approach into a customized one that accounts for manufacturing variations.
Solution Approach 2:
The patent implements a feedback mechanism where the actual injector closing time is measured and used to calculate a compensation value that adjusts the commanded injection time. This closed-loop approach continuously refines the injection timing based on actual performance, ensuring consistent fuel supply across all cylinders despite manufacturing tolerances.
3Reliability
If compensation control is performed only in sections where sensing succeeds, then measurement reliability is maintained, but control accuracy deteriorates in small flow sections where sensing fails
Solution Approach 1:
The patent uses an intermediary electrical parameter (injection current or voltage) that provides reliable measurement signals across all flow conditions. This intermediary measurement method bypasses the reliability issue of direct mechanical sensing in small flow sections, enabling accurate closing time detection regardless of flow magnitude.
Solution Approach 2:
The patent changes the measurement parameter from mechanical displacement (which fails in small flow sections) to electrical parameters (current or voltage) that remain reliable across all flow conditions. This parameter change enables consistent measurement reliability throughout the entire operating range.
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 method enables precise control of fuel injection across cylinders, accurately compensating for injector driving characteristics and reducing flow deviations, ensuring consistent fuel supply even in challenging sensing conditions.
Implementation Method 1
The injector is typically configured of a solenoid valve
Data Source
AI summary
A method for correcting an injector characteristic defining a relationship between an injector injection time and a valve closing time for a cylinder of an internal combustion engine by sensing an injector closing time includes steps of: sensing the injector closing time; determining a compensation amount for compensating for a commanded injection time using a number of sensing failures or a result of a learning of a relationship between a required commanded injection time and the injector closing time in a relevant cylinder, in addition to the number of sensing failures when there is a failure to sense the injector closing time; and controlling a commanded injection time according to an amount of required fuel injection in the relevant cylinder, based on the determined compensation amount.