Engine Torque Management via Air-Fuel Enleanment
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Solution Overview
Problem
Conventional engine torque control methods, such as spark retardation and fuel/cylinder shutoff, are inadequate for achieving significant torque reduction, especially in high-speed automatic transmissions, leading to potential component damage and inefficiencies in torque management for smooth gear shifts and fuel economy.
Innovation Solution
A control system that measures engine parameters to detect imminent transmission shifts and reduces torque output by enleaning the air/fuel charge, accompanied by advancing ignition timing to prevent misfires, thereby enabling smoother shifts and increased fuel economy, while also generating a torque reserve or adjusting for vehicle stability control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If spark retardation is used for torque control, then torque output decreases faster, but additional enrichment is required and combustion limits are reached
Solution Approach 1:
The patent changes the fuel-to-air ratio parameter by enleaning the mixture (reducing fuel quantity) rather than enriching it. This allows spark retardation to be used for fast torque control without the harmful side effect of requiring additional fuel enrichment, thus resolving the contradiction between fast torque control and fuel enrichment requirements
Solution Approach 2:
The patent applies partial fuel cut-off to specific cylinders rather than complete shutoff or uniform enrichment across all cylinders. This selective enleaning provides sufficient torque reduction for transmission shift while avoiding excessive fuel enrichment, resolving the contradiction between torque control effectiveness and fuel consumption
2Power
If fuel/cylinder shutoff is used for torque reduction, then fixed increment torque control is achieved, but rotational speed imbalance occurs
Solution Approach 1:
The patent applies enleaning selectively to specific cylinders based on their individual operating conditions and contribution to torque production. This local quality approach allows torque reduction while maintaining more balanced rotational speed across all cylinders compared to complete cylinder shutoff, resolving the contradiction between torque reduction and rotational stability
3Power
If conventional torque control is used for high-speed automatic transmission, then torque reduction is insufficient, but component damage risk increases
Solution Approach 1:
The patent detects imminent transmission shifts in advance and proactively enleans the air/fuel charge before the shift occurs. This preliminary torque reduction prepares the engine for the upcoming shift, achieving sufficient torque reduction for high-speed transmissions while preventing component damage through controlled, gradual torque management rather than abrupt changes
Solution Approach 2:
The patent dynamically adjusts the enleanment level based on real-time engine operating parameters and transmission state. This dynamic control allows the system to achieve the necessary torque reduction magnitude for high-speed transmissions while continuously monitoring and adjusting to prevent component damage, resolving the contradiction between torque reduction effectiveness and component protection
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 system achieves a more significant torque reduction of approximately 47% with reduced turbocharger exhaust energy, preventing component damage and enhancing fuel economy and transmission shift smoothness.
Implementation Method 1
decrease torque output of the engine by a desired amount by enleaning an air/fuel charge provided to a cylinder of the engine
Implementation Method 2
the engine comprises a turbocharger, and the advanced ignition of the enleaned air/fuel charge causes exhaust energy at the turbocharger to decrease thereby further decreasing the torque output of the engine
Data Source
AI summary
Control systems and methods for a vehicle comprising an automatic transmission utilize a sensor configured to measure an operating parameter of an engine of the vehicle. A controller of the vehicle is configured to detect an imminent shift of the automatic transmission based on the measured operating parameter of the engine. In response to detecting the imminent shift of the automatic transmission, the controller is configured to decrease torque output of the engine by a desired amount by enleaning an air/fuel charge provided to a cylinder of the engine. After decreasing the torque output of the engine by the desired amount, the controller is configured to control the automatic transmission to perform the shift. The decreasing of the engine torque output provides for a smoother shift of the automatic transmission and increased engine fuel economy.