Fuel Injector Drive Voltage Detection for Injection Consistency
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Solution Overview
Problem
Existing fuel injection control systems for internal combustion engines face challenges in accurately detecting variations in the behavior of the drive voltage affected by individual differences in the magnetic circuit of fuel injectors, leading to inconsistencies in injection amounts, which can worsen exhaust emission and drivability.
Innovation Solution
A fuel injection control device that energizes the magnetic circuit of the fuel injector by a specified pulse when the valve is not driven, allowing for the storage of information related to the drive voltage behavior, thereby isolating and accurately detecting variations caused by individual magnetic circuit differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the drive voltage behavior is detected during normal fuel injection operation, then the injection amount can be controlled, but the detection accuracy is reduced due to individual differences in magnetic circuit
Solution Approach 1:
The patent applies preliminary action by measuring and storing the drive voltage behavior during a test operation (energization pulse) before actual fuel injection. This allows the system to pre-determine individual magnetic circuit characteristics and use this information for accurate injection control without being affected by individual differences during normal operation.
Solution Approach 2:
The patent uses copying by creating a reference model of the drive voltage behavior during test operation. This reference waveform is stored and compared with actual drive voltage behavior during fuel injection, allowing the system to detect variations accurately by comparing against the individual-specific reference rather than relying on generic expectations.
2Quantity of substance
If the fuel injector operates in partial lift range with short injection pulse width, then the injection amount is reduced, but the linearity of injection amount change characteristic deteriorates
Solution Approach 1:
The patent applies feedback by continuously monitoring the actual drive voltage behavior during fuel injection and comparing it with the reference behavior stored from test operation. Based on detected variations, the system calculates correction amounts and adjusts subsequent injection pulses to compensate for deviations, thereby improving linearity and consistency of injection amount across different operating ranges.
3Device complexity
If the magnetic circuit individual differences are not compensated, then the device complexity is low, but the variations in injection amount increase
Solution Approach 1:
The patent applies self-service by having each fuel injector unit perform its own self-diagnosis and characterization during a test operation. The system stores the individual drive voltage behavior waveform for each injector and uses this self-generated reference data for subsequent injection control, eliminating the need for complex external calibration equipment or manual adjustment mechanisms.
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 high-accuracy detection of drive voltage variations, improving the consistency of injection amounts and reducing exhaust emissions and drivability issues.
Implementation Method 1
a fuel injector of an electromagnetic drive type... energizes a magnetic circuit of the fuel injector by a specified injection pulse to thereby open the fuel injector
Data Source
AI summary
An ECU as a fuel injection control device includes: an injector control part that energizes a magnetic circuit of a fuel injector by a specified injection pulse to thereby open the fuel injector and that energizes the magnetic circuit by a specified energization pulse within a range in which a needle valve of the fuel injector is not driven; and a storage part that stores information relating to a behavior of a drive voltage (minus terminal voltage) of the fuel injector when the magnetic circuit is energized by the injector control part by the specified energization pulse.