Engine Start Control Device Crank Angle Management
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Solution Overview
Problem
Existing vehicle engine start control devices may cause discomfort to drivers and passengers due to inconsistent engine restart methods and insufficient motor generator output, leading to reduced flexibility and increased starting shock when the crank angle is out of the predefined stop range.
Innovation Solution
A vehicle engine start control device that controls the crank angle to remain within a predetermined stop range by providing engine rotation resistance through gear ratio changes in the automatic transmission, utilizing intake and exhaust valve timing adjustments, and electric throttle valve control to maintain optimal engine startability and reduce starting shock.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the engine start control device selects one of two engine starting methods regardless of driver's intention, then the engine can be started quickly and certainly, but passengers including the driver may feel discomfort
Solution Approach 1:
The patent applies dynamics by making the engine starting method selectable and adaptable based on driver intention. The system dynamically switches between automatic selection mode and driver-selectable mode, allowing the starting method to be adjusted according to real-time driver preferences and vehicle conditions, thereby resolving the contradiction between quick engine start and driver comfort
2Reliability
If the motor generator raises engine rotation speed when crank angle is out of stop range, then the engine can be started, but the motor generator may be unable to rapidly raise rotation speed due to insufficient output power, lowering flexibility and increasing starting shock
Solution Approach 1:
The patent applies parameter changes by switching between different starting methods based on crank angle position. When the crank angle is within the stop range, the system uses motor generator starting with optimized parameters for smooth operation. When the crank angle is outside the stop range, the system switches to DC starter method, changing the starting parameters to accommodate the different crank angle condition, thereby maintaining both reliability and flexibility
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
Ensures quick and certain engine restart with reduced discomfort by maintaining the crank angle within the suitable range for restart, minimizing engine starting shock and enhancing engine startability.
Implementation Method 1
adjusting a valve timing of the cylinder to generate one of expansion or compression braking torque
Implementation Method 2
the motor generator acts as a motor
Implementation Method 3
the engine start control device of JP 2004-239111 A starts the engine with a DC starter acting as a motor
Data Source
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Figure 6
AI summary
Providing a vehicle engine start control device capable of suppressing a feeling of discomfort brought to a driver and rapidly and certainly starting an engine when the automatically stopped engine is restarted. The engine 12 is stopped with the crank angle AGCR controlled such that the crank angle AGCR at the time of automatic stop of the engine falls within the crank angle stop range AGST. The engine rotation resistance control means 132 provides the engine rotation resistance control in which the engine rotation resistance generated due to a change in air pressure in the combustion chamber of the engine 12 is made larger while the engine 12 is in the automatic stop period, as compared to the time of engine start. Therefore, since the crankshaft 14 is hardly rotated by an external force while the engine 12 is in the automatic stop period and the crankshaft 14 is stopped within or in the vicinity of the crank angle stop range AGST that is favorable engine startability at the time of restart of the engine 12, the engine can quickly and certainly be started while suppressing a feeling of discomfort brought to a driver.