Fuel Injection Drive Device Voltage Drop Correction
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Solution Overview
Problem
In fuel injection devices, variations in injection amount occur due to fluctuations in the high voltage source's voltage, leading to inconsistent injection timing and amount, especially during multistage injection, where the controllable injection amount is small and the injection pulse width is large.
Innovation Solution
A drive device for fuel injection devices that adjusts the pulse width of the injection pulse based on the energization time, correcting for variations by extending the pulse width when the fuel injection timing or period overlaps between cylinders and reducing it when the voltage of the high voltage source decreases, thereby stabilizing the injection amount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the high voltage source voltage fluctuates during multistage injection, then the injection amount varies, but increasing the injection pulse width to compensate increases the variation when voltage drops
Solution Approach 1:
The patent applies feedback control by detecting the actual coil current during injection and comparing it with the target current. When voltage fluctuations cause current deviation, the system adjusts the injection pulse width in real-time to maintain the desired injection amount, thereby resolving the contradiction between precision and consistency
Solution Approach 2:
The patent dynamically changes the injection pulse width parameter based on detected voltage fluctuations and current measurements. By adjusting this parameter in response to varying electrical conditions, the system maintains consistent injection amounts despite voltage drops during multistage injection sequences
2Quantity of substance
If the injection pulse width is extended to compensate for voltage drop, then the injection amount increases, but the injection timing becomes delayed
Solution Approach 1:
The patent applies preliminary action by detecting voltage fluctuations before they significantly impact injection and pre-adjusting the pulse width. This proactive approach compensates for upcoming voltage drops without causing timing delays, as the adjustment is made in anticipation rather than reaction
3Quantity of substance
If the voltage of the high voltage source decreases during multistage injection, then the current flowing through the coil decreases, but extending the pulse width to maintain injection amount increases the variation in injection timing
Solution Approach 1:
The patent uses feedback control to monitor both current and timing parameters simultaneously. When voltage decrease affects current, the system adjusts pulse width while continuously monitoring timing deviation, thereby maintaining injection amount without excessive timing variation
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 effectively reduces variation in injection amount and timing by accurately controlling the injection pulse width, ensuring consistent fuel delivery even under conditions of voltage drop, thereby improving the responsiveness and precision of fuel injection.
Implementation Method 1
energizing a solenoid to apply a magnetic attraction force between a fixed core and a mover
Implementation Method 2
applying a high voltage to the solenoid when the valve body opens, and after the drive current flowing through the solenoid reaches a predetermined current value
Data Source
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AI summary
The objective of the present invention is to correct deviation in the injection amount and changes in the injection timing when the voltage of a high-voltage source for a drive device decreases. This drive device for a fuel injection device is equipped with a function whereby, when the pulse width of the injection pulse is set to an energization time 815 that closes a valve after a drive current has been switched to a maintenance current, the injection pulse width when the voltage of a high-voltage source has decreased is corrected so as to be longer than the injection pulse width when the voltage of the high-voltage source has not decreased, and, when the pulse width of the injection pulse is set to an energization time 804' that closes the valve before the drive current has been switched to the maintenance current, the absolute value of the amount of correction of the injection pulse width is made smaller than when the injection pulse width is set to the energization time 815 that closes the valve after the drive current has been switched to the maintenance current.