Internal Combustion Engine Cold Start Control via Variable Valve Timing
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Solution Overview
Problem
Existing internal combustion engines struggle to effectively control exhaust gas emissions based on environmental temperature, particularly during cold starts, as the variable valve timing mechanism is not adequately controlled for varying temperatures.
Innovation Solution
An internal combustion engine with a controller that sets a predetermined rotational speed based on environmental temperature before the first ignition, using a variable valve mechanism to optimize intake valve timing and promote fuel atomization, and employing a hybrid drive motor for motoring to warm the combustion chamber effectively, thereby reducing exhaust gas emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the closing timing of the intake valve is uniformly set to be more advanced than the reference timing during steady operation, then the intake air is retained in the cylinder and compressed to raise the temperature, but it is difficult to perform appropriate control to reduce exhaust gas according to the environmental temperature
Solution Approach 1:
The patent applies dynamics by making the valve timing adjustable based on environmental temperature. The variable valve timing mechanism changes the closing timing of the intake valve dynamically according to the environmental temperature conditions, transitioning from a fixed uniform advance timing to a dynamic timing that adapts to different temperature environments, thereby resolving the contradiction between achieving sufficient compression temperature and adapting to varying environmental conditions
Solution Approach 2:
The patent applies parameter changes by modifying the valve timing parameter based on environmental temperature. The controller adjusts the closing timing of the intake valve as a variable parameter according to the detected environmental temperature, allowing the system to optimize both compression temperature and environmental adaptability by changing this key operational parameter
2Temperature
If the rotational speed is set to be particularly high during cold start, then the combustion chamber is warmed effectively through friction and inertia supercharging, but the device complexity increases due to the need for precise rotational speed control
Solution Approach 1:
The patent applies self-service by utilizing the engine's own operational parameters (rotational speed, friction, inertia supercharging) to warm the combustion chamber during cold start. The system uses the engine's inherent mechanical processes rather than external heating devices, and the controller leverages existing sensor and actuator infrastructure to achieve temperature control, thereby avoiding additional complex subsystems
Solution Approach 2:
The patent applies preliminary action by performing rotational speed control and valve timing adjustment before the first ignition occurs. The controller prepares the combustion chamber by warming it through controlled motoring at high rotational speed and optimizing intake air retention through advanced valve closing timing, ensuring the combustion chamber is ready for efficient combustion before fuel injection and ignition begin
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 engine achieves reduced exhaust gas emissions by warming the combustion chamber through friction and inertia supercharging, promoting fuel atomization, and optimizing valve timing, which also reduces the need for precious metal catalysts and lowers noise vibration.
Implementation Method 1
it is possible to effectively warm the inside of the combustion chamber due to friction between a cylinder and a piston
Implementation Method 2
inertia supercharging when the rotational speed of the internal combustion engine body is set to be particularly high
Data Source
AI summary
An internal combustion engine includes an internal combustion engine body including an intake valve and an exhaust valve, and a controller configured or programmed to perform a control to set a rotational speed of the internal combustion engine body to a predetermined rotational speed based on an environmental temperature at a time of starting the internal combustion engine body, and perform a control to drive the internal combustion engine body at the set predetermined rotational speed during a time period until when fuel is supplied to a combustion chamber of the internal combustion engine body and first ignition is performed.