Engine Start Fuel Injection Timing Transition
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Solution Overview
Problem
Engines coupled to automatic transmissions face challenges in controlling engine speed and torque during start-stop operations, particularly in heavy traffic or stop-and-go conditions, where driver input intentions are not accurately followed due to limited direct control over transmission clutches.
Innovation Solution
A method involving automatic engine starting with split fuel injection during the start cycle, transitioning to single injection based on intake manifold pressure when engine speed exceeds a threshold, allowing for robust engine torque control and improved combustion stability at lower torque levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the engine controller concentrates on controlling the engine in specific modes (start mode, idle speed control mode, or engine torque control mode), then engine speed control and torque management are improved, but the driver's direct control over transmission clutches is reduced
Solution Approach 1:
The system dynamically transitions between different fuel injection modes (split injection and single injection) based on real-time engine operating conditions such as manifold pressure and engine speed. This dynamic adaptation allows the engine controller to optimize control precision while maintaining responsiveness to driver inputs through conditional mode switching
2Stability of the object's composition
If split fuel injection is used during engine start, then combustion stability at lower torque levels is improved, but engine torque control robustness may be reduced when manifold pressure drops
Solution Approach 1:
The system dynamically switches between split injection and single injection modes based on manifold pressure thresholds. Split injection is used when manifold pressure is above the threshold to optimize combustion stability, while single injection is used when pressure drops below the threshold to maintain torque control robustness
Solution Approach 2:
The system changes the fuel injection parameter (from split to single injection) in response to changing manifold pressure conditions. This parameter adaptation allows the system to maintain optimal performance across varying operating conditions, balancing combustion stability with torque control reliability
3Speed
If the engine transitions directly from start mode to torque control mode when the driver depresses the throttle, then responsiveness to driver inputs is improved, but engine speed control precision may be compromised
Solution Approach 1:
The system dynamically adjusts the transition criteria between engine modes based on driver input detection. When throttle depression is detected, the system accelerates the transition from start mode to torque control mode, optimizing response speed while maintaining speed control precision through conditional logic
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 engine speed control and torque management for automatic transmission engines, reducing emissions and improving transitions between engine modes by considering engine operating conditions beyond speed, thus providing better responsiveness to driver inputs.
Implementation Method 1
a fuel injector delivers fuel to an engine cylinder during a compression stroke
Implementation Method 2
a spark plug delivers an electric spark to the air-fuel mixture in the combustion chamber
Implementation Method 3
The piston may be moved up and down in the cylinder
Implementation Method 4
The exhaust valve may be opened to allow exhaust to leave the combustion chamber
Data Source
AI summary
A method for improving starting of an engine that may be repeatedly stopped and started is presented. In one embodiment, the method controls a transition from split fuel injection timing during an engine start to single event fuel injection during idle speed or engine torque control modes. The method better manages vehicle launch performance when the engine is restarted while coupled to an automatic transmission that is in gear.