Spark-Ignition Engine Control for Catalyst Warm-Up
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Solution Overview
Problem
The challenge is to achieve compatibility between combustion stability and warm-up performance for a spark-ignition internal combustion engine, particularly when the alcohol concentration of the fuel is high, as reducing ignition timing retard degrades catalyst warm-up performance.
Innovation Solution
A control apparatus that includes a fuel injection valve, a catalyst in the exhaust passage, and an electronic control unit to acquire alcohol concentration and manipulate ignition timing and air quantity, advancing ignition timing and increasing air intake when alcohol concentration is high to maintain stability and performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If ignition timing is retarded for catalyst warm-up control, then catalyst warm-up performance is improved, but combustion stability deteriorates when alcohol concentration is high
Solution Approach 1:
The control apparatus dynamically adjusts ignition timing based on detected alcohol concentration. When alcohol concentration is high, the system advances ignition timing to maintain combustion stability, while when alcohol concentration is low, it retards ignition timing to improve catalyst warm-up performance. This parameter change strategy resolves the contradiction by making the system adaptive to varying fuel conditions.
2Stability of the object's composition
If ignition timing is advanced to maintain combustion stability with high alcohol concentration, then combustion stability is improved, but catalyst warm-up performance deteriorates
Solution Approach 1:
The system implements dynamic ignition timing adjustment based on real-time alcohol concentration detection. The control apparatus continuously monitors fuel composition and modifies ignition timing accordingly, transitioning between advanced and retarded timing strategies based on current operating conditions. This dynamic approach allows the system to optimize both combustion stability and catalyst warm-up performance according to varying alcohol concentrations.
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 approach enhances combustion stability and warm-up performance by adjusting ignition timing and air intake based on alcohol concentration, reducing the risk of unstable combustion and catalyst warm-up degradation.
Implementation Method 1
a spark plug
Implementation Method 2
a spark-ignition internal combustion engine
Implementation Method 3
a catalyst that is provided in an exhaust passage
Data Source
AI summary
When a catalyst of an internal combustion engine is not activated, a control apparatus retards the ignition timing of a spark plug, and thereby, executes a rapid warm-up control of the catalyst. However, on this occasion, when alcohol concentration Ca is high, the control apparatus sets the ignition timing to a more advanced side than when the alcohol concentration Ca is low. When the ignition timing is set to an advanced side, opening angle θ of a throttle valve is manipulated such that command value qsjc for the quantity of the air that is filled into a combustion chamber is increased. Thereby, compared with when the command value qsjc is not increased, the quantity of the fuel that is injected from a cylinder injection valve increases, and the thermal energy of exhaust gas increases.