Automatic Engine Stop Inhibition for Emissions Cooling
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Solution Overview
Problem
Automatic engine stopping in vehicles can lead to catalyst degradation due to high temperatures during high-speed and high-load conditions, which reduces the vehicle's emissions compliance and increases fuel consumption.
Innovation Solution
Inhibiting automatic engine stopping when the emissions device temperature exceeds a threshold, allowing the engine to continue operating under low load conditions to cool the emissions device, and adjusting engine operation to reduce torque reserve and increase battery charging thresholds to enhance cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If automatic engine stopping is implemented to conserve fuel, then fuel consumption is reduced, but emissions device degradation occurs due to high temperatures
Solution Approach 1:
The system performs preliminary cooling action by operating the engine at low load conditions before automatically stopping the engine. This preliminary action reduces the emissions device temperature to below the threshold temperature, preventing thermal degradation while still enabling fuel-saving automatic engine stopping.
Solution Approach 2:
The system dynamically adjusts engine operation by transitioning from high load to low load conditions. This dynamic operation allows the engine to produce cooler exhaust gases that cool the emissions device, creating a time-varying temperature profile that protects the emissions device while maintaining fuel efficiency.
2Use of energy by moving object
If the engine is stopped to reduce fuel consumption, then fuel efficiency is improved, but emissions compliance is compromised due to catalyst degradation
Solution Approach 1:
The system performs preliminary cooling action by operating the engine at low load conditions before automatically stopping the engine. This preliminary action reduces the emissions device temperature to below the threshold temperature, preventing thermal degradation while still enabling fuel-saving automatic engine stopping.
3Temperature
If the engine operates continuously to cool the emissions device, then emissions device temperature is reduced, but fuel consumption increases
Solution Approach 1:
The system applies partial action by operating the engine at low load conditions rather than full load. This partial operation provides sufficient cooling effect to reduce emissions device temperature while consuming significantly less fuel compared to continuous full-load operation. The cooling action is excessive enough to achieve the temperature threshold but minimized through low load operation.
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 reduces emissions device degradation, speeds up cooling, and conserves fuel by allowing the engine to operate during low load conditions, thereby maintaining emissions compliance and optimizing fuel efficiency.
Implementation Method 1
allowing the engine to continue operating under low load conditions to cool the emissions device
Data Source
AI summary
A method for operating a vehicle that may be automatically stopped and started is described. In one example, the method includes inhibiting automatic engine stopping in response to a temperature of an emissions device exceeding a threshold temperature. In addition, additional actions may be taken to reduce the temperature of the emissions device when automatic engine stopping is inhibited.