Slipping Clutch Control for Quiet Internal Combustion Engine Restart
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Solution Overview
Problem
Existing technologies for internal combustion engine control systems face challenges in restarting the engine smoothly during re-acceleration, leading to torque shock and gear meshing noise, especially when the engine is stopped and restarted at low speeds, which can result in inefficient energy consumption.
Innovation Solution
A control apparatus that detects the accelerator opening degree and uses a slipping clutch engagement to restart the engine when the accelerator is pressed, ensuring the engine rpm exceeds the target cranking rpm, thereby reducing torque shock and eliminating gear meshing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the clutch is engaged directly to restart the engine from a stop state, then the engine can be restarted quickly, but torque shock is generated at the moment of engagement
Solution Approach 1:
The clutch engagement state is dynamically adjusted during engine restart. The clutch control unit engages the clutch in a slipping state initially, then progressively increases the direct-coupling ratio as engine RPM increases, rather than engaging directly at full coupling. This dynamic transition resolves the contradiction by allowing quick restart while reducing torque shock through controlled slippage.
Solution Approach 2:
The clutch is engaged in a slipping manner before full direct coupling is achieved. This preliminary engagement phase allows the engine to begin rotating and building RPM gradually, preparing the system for full power transmission without the shock of immediate direct coupling. The slipping engagement serves as a buffer that prevents sudden torque transmission.
2Loss of energy
If the starter is used to restart the engine when rotation is stopped, then engine idling is prevented, but gear meshing noise is generated
Solution Approach 1:
The traditional starter motor mechanism is replaced with a clutch-based engine restart system. Instead of using the starter's pinion gear to mesh with the flywheel, the invention uses the clutch to transmit torque from the automatic transmission to the engine crankshaft. This substitution eliminates the gear meshing noise inherent in starter operation while maintaining the ability to restart the engine without idling.
Solution Approach 2:
The clutch serves as an intermediary mechanism between the automatic transmission and the engine during restart. Rather than directly cranking the engine with the starter, the clutch mediates the power transmission by engaging gradually and allowing the engine to be driven by the transmission's output shaft. This intermediary approach avoids the direct gear engagement noise of the starter while achieving the same restart function.
3Speed
If the clutch is directly engaged to rotate the stopped engine, then restart is achieved, but shock is generated and at low vehicle speed the engine rpm may not reach sufficient cranking rpm
Solution Approach 1:
The clutch direct-coupling ratio is dynamically controlled during the restart process. At low vehicle speeds, the clutch control unit maintains a slipping engagement state longer, allowing the engine RPM to build up gradually through the transmitted torque. The direct-coupling ratio is increased progressively as engine RPM increases, ensuring sufficient cranking RPM is achieved without generating shock. This dynamic adjustment adapts to low-speed conditions that would otherwise prevent adequate cranking RPM.
4Use of energy by moving object
If fuel supply is stopped during deceleration to improve fuel efficiency, then fuel economy improves, but the engine must be restarted quickly when accelerator is pressed
Solution Approach 1:
The clutch is engaged in advance during the fuel-supply stop state, preparing the power transmission path for quick engine restart. When the driver presses the accelerator, the clutch is already in position to immediately transmit torque from the automatic transmission to the engine. This preliminary engagement eliminates delays associated with clutch engagement during restart, ensuring rapid response while maintaining fuel efficiency through the fuel-supply stop strategy.
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 solution allows for quiet and shock-free engine restarts during re-acceleration, maintaining fuel efficiency and reducing energy consumption by ensuring the engine reaches sufficient cranking rpm without generating foreign noise.
Implementation Method 1
the clutch is engaged in a slipping manner so that internal combustion engine rpm becomes equal to or higher than target cranking rpm to restart the internal combustion engine
Data Source
AI summary
Provided is a control apparatus for an internal combustion engine, which quietly restarts the engine with a reduced torque shock when a re-acceleration request is made by a driver. A control apparatus for an internal combustion engine, for controlling a clutch provided between the internal combustion engine and an automatic transmission, includes: an accelerator opening-degree detection unit for detecting a pressing amount of an accelerator; a fuel-supply stopping unit for stopping fuel injection to the internal combustion engine when the accelerator is not pressed down; and a clutch direct-coupling ratio control unit capable of arbitrarily changing a power amount transmitted by the clutch from engagement for direct coupling to disengagement of the clutch, in which, when the accelerator is pressed down while the clutch is disengaged in a fuel-supply stop state, the clutch is engaged in a slipping manner so that internal combustion engine rpm becomes equal to or higher than target cranking rpm to restart the internal combustion engine.