Fuel Injector Control Timing for Intake Vacuum Pressure
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Solution Overview
Problem
At higher engine speeds and throttle openings, the reduced pressure differential and shorter pressure signal duration in fuel injectors lead to reduced fuel delivery efficiency, causing variances in engine operation, instability, and audible noises due to the injector remaining open after the intake valve closes.
Innovation Solution
A method of controlling fuel injection events by determining engine operating conditions and initiating fuel injection prior to the desired pressure, with the injection event duration centered around the maximum negative pressure point to ensure fuel delivery during the intake valve's open cycle, and adjusting the duration to alter the air:fuel ratio as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fuel injection is initiated at or after maximum pressure point, then fuel delivery timing is simplified, but the time available for fuel delivery is reduced and maximum flow rate cannot be achieved
Solution Approach 1:
The fuel injection event is initiated before the maximum negative pressure point occurs in the intake chamber. This preliminary action ensures that the injector valve is already open when the optimal pressure differential is achieved, maximizing the time available for fuel delivery and enabling the system to achieve maximum flow rate demanded by the engine.
2Productivity
If fuel injection duration is extended to ensure complete fuel delivery, then maximum flow rate is achieved, but the injector may remain open after intake valve closes causing engine operation instability
Solution Approach 1:
The fuel injection event duration is dynamically adjusted based on real-time detection of intake valve closure timing. The controller monitors when the intake valve closes and terminates the fuel injection event at that point, ensuring complete fuel delivery during the valve open period while preventing injector operation after valve closure that would cause engine instability and popping noises.
3Productivity
If fuel injection is timed to match pressure signal duration, then fuel delivery efficiency is optimized, but the initial portion of pressure signal before maximum pressure is not utilized
Solution Approach 1:
The fuel injection event is initiated before the maximum negative pressure point occurs in the intake chamber. This preliminary action ensures that the injector valve is already open when the optimal pressure differential is achieved, maximizing the time available for fuel delivery and enabling the system to achieve maximum flow rate demanded by the engine.
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 enhances fuel delivery efficiency, stabilizes engine operation, and reduces noise by ensuring fuel is injected during the optimal pressure window and maintaining consistent air:fuel ratios across varying engine conditions.
Implementation Method 1
The flow rate of fuel through the valve depends upon the pressure differential across the injector
Data Source
AI summary
In at least some implementations, a method of controlling fuel injection events, includes determining at least one engine operating condition, determining timing of a desired pressure in an engine intake chamber or at the outlet of a fuel injector, and initiating a fuel injection event as a function of the at least one engine operating condition and the desired pressure. The fuel injection event is initiated prior to the desired pressure occurring and wherein the fuel injection event occurs for a duration such that the fuel injection event terminates after the desired pressure occurs.