Fuel Injector Drive Control for Cylinder Injection Variation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel injection devices face challenges in accurately controlling the minimum injection quantity and reducing variations due to valve opening and closing lag times, which affect fuel consumption and particulate matter emissions, particularly in downsized engines with divided injection systems.
Innovation Solution
A drive device for fuel injection systems that detects the valve opening and closing timings by analyzing the current differential values to correct injection quantities, using a configuration with multiple voltage sources and switching elements to manage the valve operation and minimize variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the injection pulse width is shortened to control minimum injection quantity, then fuel consumption improves, but the needle rebound phenomenon causes nonlinear relationship between injection pulse width and injection quantity, increasing the controllable minimum injection quantity
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing correction values for the nonlinear relationship between injection pulse width and injection quantity in a correction value map. Before actual fuel injection, the ECU retrieves the appropriate correction value based on the injection pulse width and uses it to correct the target injection quantity, thereby compensating for the needle rebound effect and achieving precise minimum injection quantity control.
Solution Approach 2:
The patent implements feedback by detecting the actual injection quantity through injection quantity detection means (such as pressure sensors or flow meters) and comparing it with the target injection quantity. The detected deviation is fed back to the ECU, which adjusts the injection pulse width or correction values accordingly to minimize the difference between actual and target injection quantities, thereby improving control precision despite needle rebound.
2Reliability
If individual fuel injection devices are set with the largest injection quantity as the controllable minimum injection quantity to ensure stability, then injection quantity stability improves, but the controllable minimum injection quantity increases
Solution Approach 1:
The patent applies local quality by performing individual adaptation for each fuel injection device. The ECU detects the actual injection quantity characteristics of each specific injection device and creates device-specific correction values or adaptation parameters. This allows each injection device to operate at its optimal minimum injection quantity level rather than using a conservative uniform setting, thereby reducing the overall controllable minimum injection quantity while maintaining stability through localized optimization.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting injection pulse width parameters based on detected needle rebound characteristics and individual device variations. The system modifies injection timing, pulse width duration, and correction values to optimize the relationship between injection pulse width and actual injection quantity, enabling precise control of minimum injection quantity without requiring excessive margins for stability.
3Object-generated harmful factors
If divided injection is implemented to inhibit particulate matter generation, then emission control improves, but the requirement for minute injection quantity control increases
Solution Approach 1:
The patent applies segmentation by dividing the total fuel injection into multiple separate injection pulses (divided injection) within one engine cycle. The ECU controls multiple injection events with individually optimized pulse widths, utilizing correction values specific to each injection timing and duration. This segmentation approach reduces particulate matter by improving fuel vaporization and distribution while the patent's correction mechanism ensures each divided injection pulse achieves the required precision for minimum quantity control.
4Quantity of substance
If the intermediate lift region is used to achieve smaller injection quantities, then minimum injection quantity decreases, but individual variations in injection quantity increase due to dimensional tolerance and aging
Solution Approach 1:
The patent applies preliminary action by pre-characterizing each fuel injection device's performance in the intermediate lift region during manufacturing or initial operation. The ECU stores correction values that account for individual device variations in the intermediate lift region, allowing the system to compensate for dimensional tolerance and aging effects before they significantly impact performance. This preliminary adaptation enables reliable use of the intermediate lift region while maintaining injection quantity consistency.
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
The solution enables precise control of injection quantities, reduces variations among cylinders, improves fuel consumption, and decreases particulate matter emissions by ensuring consistent valve operation timing.
Implementation Method 1
a solenoid 105; when a current is supplied to the solenoid 105, a magnetic field is generated and a magnetic suction force acts on the needle 102
Implementation Method 2
a magnetic suction force acts on the needle 102, and the needle 102 moves in a valve opening direction
Implementation Method 3
changes of a current differential value, that is, changes of a differential value of the current flowing to the solenoid 105 are detected as timing when the valve body 114 starts to open and timing when the valve body 114 finishes closing
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A drive device capable of detecting individual variations of an injection quantity of a fuel injection device of each cylinder and adjusting a current waveform provided to an injection pulse width and a solenoid such that the individual variations of the fuel injection devices are reduced. The fuel injection device in the present invention includes a valve body 114 that closes a fuel passage by coming into contact with a valve seat 118 and opens the fuel passage by separating from the valve seat 118 and a magnetic circuit constructed of a solenoid 105, a fixed core 107, a nozzle holder 101, a housing 103, and a needle 102 and when a current is supplied to the solenoid 105, a magnetic suction force acts on the needle 102 and the needle 102 has a function to open the valve body 114 by colliding against the valve body 114 after performing a free running operation and changes of acceleration of the needle 102 due to collision of the needle 102 against the valve body 114 are detected by a current flowing through the solenoid 105.