Start Controller Piston Position Intake Pressure Starter Torque
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Solution Overview
Problem
The existing engine start control systems face challenges in reducing the torque of the starter motor during engine restarts, particularly when the piston positions in the cylinders are not within the desired target range, leading to increased starter torque due to intake pressure increases.
Innovation Solution
A start controller system that includes stop position detection, intake pressure detection, and control means to determine if the piston positions are within a target range. If not, and the intake pressure is lower than atmospheric pressure, the system initiates engine start using the starter motor without waiting for the conventional engine start conditions to be met, thereby reducing starter torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is stopped automatically to improve fuel efficiency, then fuel efficiency is improved, but the torque of the starter motor increases when restarting due to piston position deviation
Solution Approach 1:
The control device performs preliminary detection of piston position and intake pressure before engine restart, and proactively adjusts the restart timing or throttle valve opening to ensure the engine restarts at an optimal piston position, thereby preventing excessive starter torque while maintaining fuel efficiency benefits
2Manufacturing precision
If the intake amount of the stop-time compression stroke cylinder is increased to suppress piston lift, then the stop position accuracy is improved, but the response delay of the throttle valve causes insufficient intake increase and position shift
Solution Approach 1:
The control device detects the piston position and intake pressure in advance before the throttle valve response delay becomes critical, and pre-adjusts the throttle valve opening degree or timing to compensate for the anticipated response delay, ensuring the piston reaches the desired stop position accurately
Solution Approach 2:
The control device continuously monitors the actual piston position and intake pressure, and dynamically adjusts the throttle valve opening in real-time based on feedback from position sensors and pressure sensors, thereby overcoming the throttle valve response delay and achieving precise stop position control
3Measurement precision
If the engine start is delayed to wait for engine start conditions to be satisfied, then the control precision is maintained, but the intake pressure increases and starter torque increases
Solution Approach 1:
The control device performs preliminary assessment of piston position and intake pressure conditions, and when the piston position is favorable and intake pressure is low, it initiates engine start immediately without waiting for all conventional start conditions to be fully satisfied, thereby reducing starter torque while maintaining adequate control precision through real-time monitoring
Data Source
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AI summary
The start controller for an engine includes: stop position detection means that detects a position of a piston in each cylinder in an engine stop time; intake pressure detection means that detects an intake pressure as a pressure in an intake passage; and a determination section that determines whether the position of the piston in each of the cylinders detected by the stop position detection means is within a specified target range X0 after the engine is stopped. In the case where it is determined that the position of the piston in each of the cylinders after the engine stop is out of the target range and the intake pressure detected by the intake pressure detection means is lower than an atmospheric pressure, the engine is started by start means even when an engine start condition is not satisfied.