Engine Starter Control Mode Switching for Rapid Re-Start
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Solution Overview
Problem
Conventional engine starting devices with a single drive command for pinion gear engagement and rotation lead to time lags between engine re-start requests and actual cranking, causing discomfort due to synchronization issues between the pinion and ring gears, especially during sharp engine speed reductions.
Innovation Solution
An engine starting device with a starter capable of independent control of an actuator for engaging the pinion gear and a motor for rotating it, using two modes: one where the motor is driven before the actuator and another where the actuator engages the gears before the motor, with mode selection based on engine rotation speed reduction rates to minimize synchronization delays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the starter waits for engine rotation speed to sufficiently lower before engagement, then smooth gear engagement is achieved, but time lag occurs between re-start request and actual cranking
Solution Approach 1:
The control device performs preliminary action by rotating the pinion gear before engagement when engine rotation speed is high, so that the pinion gear rotation speed synchronizes with the engine rotation speed before the actual engagement occurs. This preliminary rotation action eliminates the time lag while ensuring smooth engagement.
Solution Approach 2:
The system dynamically adjusts the control mode based on real-time engine rotation speed conditions. When engine rotation speed is high, the control device switches to a mode where the motor rotates the pinion gear before engagement. When engine rotation speed is already low, the system uses conventional engagement mode, making the system adaptable to different operational states.
2Loss of time
If the motor rotates the pinion gear before engagement during sharp engine speed reduction, then rapid re-start is achieved, but gear engagement synchronization deteriorates
Solution Approach 1:
The control device continuously monitors engine rotation speed and its reduction rate, using this feedback to determine the appropriate control mode. When sharp reduction is detected, the system switches to engagement-first mode to maintain synchronization. This feedback mechanism ensures reliable engagement while enabling rapid re-start when conditions permit.
Solution Approach 2:
The system changes the control parameter sequence based on engine speed reduction characteristics. Under normal conditions, the sequence is motor rotation then engagement. Under sharp reduction conditions, the sequence changes to engagement then motor rotation, optimizing performance for different operational scenarios.
3Adaptability or versatility
If independent control of actuator and motor is implemented, then flexible mode switching is achieved, but device complexity increases
Solution Approach 1:
The control device integrates multiple functions into a single unit: it monitors engine rotation speed, determines reduction rate, selects appropriate control modes, and coordinates both the actuator and motor. This universal control approach achieves flexible mode switching without proportionally increasing overall system complexity.
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
Enables rapid engine re-start without waiting for reduced engine speed, while maintaining smooth gear engagement, reducing driver discomfort and operational inefficiencies.
Implementation Method 1
an actuator (232) for moving the pinion gear (260) to an engagement position with the first gear (110)
Data Source
AI summary
A device for starting an engine includes a starter for starting the engine and an ECU. The starter includes a pinion gear for engagement with a ring gear for cranking the engine, an actuator structured to engage the pinion gear with a ring gear, and a motor for rotating the pinion gear. The actuator and the motor can individually be controlled. The ECU has a rotation mode for driving the motor prior to drive of the actuator and an engagement mode for causing the actuator to engage the pinion gear and the ring gear with each other prior to drive of the motor. When a request to start the engine is made, the ECU switches selection between the rotation mode and the engagement mode based on a rotation speed of the engine and a reduction rate in rotation speed of the engine.