Engine Control Unit Reverse Rotation Inertia Start
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Engine start failures due to high resistive forces in the compression stroke, particularly in warm environments, where the crankshaft may stop rotating before reaching the top dead center, leading to unreliable engine starting.
Innovation Solution
An engine control method that uses a motor connected to the crankshaft to run the engine in a first section shifted from the top dead center in the compression stroke, creating a repulsive force, then transitions to a reverse direction during the combustion stroke, followed by braking and re-starting in the forward direction to increase inertial force and enhance starting reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the engine is started in a warm environment, then the compression pressure increases, but the resistive force becomes too high causing the crankshaft to stop before top dead center
Solution Approach 1:
The patent applies reverse rotation of the crankshaft to generate inertial torque that overcomes the high compression pressure resistive force during warm environment starting. By rotating the crankshaft in reverse direction before normal starting, inertial energy is accumulated to push the piston past top dead center, preventing stoppage and ensuring reliable engine start under high temperature conditions.
2Reliability
If intermittent torque application is used to reduce friction, then the engine can start more easily, but the control complexity increases
Solution Approach 1:
The patent employs periodic reverse rotation followed by normal rotation sequences to reduce static friction and generate inertial torque. This periodic action pattern (reverse-rotate, stop, normal-rotate) creates dynamic friction reduction and inertial effects that facilitate engine starting, while the control logic remains relatively simple compared to complex intermittent torque modulation systems.
3Reliability
If reverse direction rotation is used to increase inertial force, then the engine startability improves, but the risk of rotating beyond top dead center increases
Solution Approach 1:
The patent incorporates feedback control through a control unit that monitors crankshaft position and rotational speed during reverse rotation. Based on this feedback, the control unit adjusts the motor torque and rotational speed to ensure the crankshaft stops at the appropriate position before top dead center, preventing over-rotation while maximizing inertial torque generation for reliable engine starting.
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 method increases the repulsive force in the cylinder, allowing the engine to start reliably by leveraging the inertial force, thereby improving engine startability and reducing the risk of start failures, especially in warm conditions.
Implementation Method 1
a motor is connected to a crankshaft of the engine so as to be able to apply torque to the crankshaft
Implementation Method 2
air in a cylinder of the engine is compressed to have an increased repulsive force
Implementation Method 3
the inertial force can be increased to improve the startability of the engine
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An engine control method includes: a step of determining whether or not a crank angle of the engine lies in a first section between a top dead center in a compression stroke and a first angle in a case where the number of revolutions of the engine is lower than the prescribed number of revolutions; a step of running the engine in a forward direction by driving a motor that applies a torque to a crank of the engine in the forward direction in a case where the crank angle of the engine does not lie in the first section; a step of determining whether or not the crank angle of the engine lies in the first section; a step of determining whether or not the crank angle of the engine lies in a second section between a top dead center in a combustion stroke and a second angle; a step of braking the motor in a case where it is determined in the sixth step that the crank angle of the engine lies in the second section; and a step of running the engine in the forward direction by driving the motor in the forward direction in a case where it is determined in the eighth step that there is the request for restart of the engine.