Engine Start Control for Cold-Start Fuel Economy
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Solution Overview
Problem
In cold start situations, existing engine start control methods lead to excessive engine rotation speed, resulting in poor fuel economy due to inefficient catalyst activation and air-fuel ratio management.
Innovation Solution
An engine start control apparatus and method that includes an intake air amount control device, fuel supply device, and igniting device, with an engine operation state detecting unit, ignition timing retardation, and fuel injection management to maintain the engine at target idling rotation speed while ensuring a stable air-fuel ratio, using an intake throttle and fuel injection control to prevent lean air-fuel ratios.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ignition timing is quickly retarded and intake air amount is increased to quickly activate the catalyst and make the engine fire, then the engine smoothly and quickly fires, but the engine rotation speed exceeds the target_idling rotation speed, reducing fuel economy
Solution Approach 1:
The patent applies preliminary action by opening the intake throttle before the ignition timing retardation occurs. This advance opening of the throttle allows the engine to smoothly and quickly fire while preventing the engine rotation speed from excessively exceeding the target_idling rotation speed, thus resolving the contradiction between reliable catalyst activation and fuel economy.
2Productivity
If the engine rotation speed is allowed to exceed target_idling to ensure complete ignition and catalyst activation, then the engine fires completely, but fuel economy deteriorates due to higher fuel consumption at elevated rotation speeds
Solution Approach 1:
The intake throttle is opened in advance before the ignition timing retardation, ensuring complete ignition and catalyst activation while controlling the engine rotation speed to minimize fuel consumption.
Solution Approach 2:
The engine control unit monitors the engine rotation speed and adjusts the ignition timing and intake air amount based on feedback, ensuring that the rotation speed does not excessively exceed the target_idling rotation speed while maintaining complete ignition.
3Reliability
If ignition timing is retarded to accelerate catalyst warming-up, then catalyst activation is improved, but the air-fuel ratio may become lean, requiring additional fuel injection control
Solution Approach 1:
The engine control unit monitors the air-fuel ratio and adjusts the fuel injection amount based on feedback, preventing the air-fuel ratio from becoming lean when ignition timing is retarded for catalyst activation.
Solution Approach 2:
The patent changes the fuel injection amount as a parameter to compensate for the air-fuel ratio changes caused by ignition timing retardation, ensuring stable air-fuel ratio while maintaining catalyst activation.
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
Swiftly stabilizes engine operation at target idling speed, maintaining fuel efficiency by preventing excessive fuel consumption and ensuring effective catalyst performance through precise air-fuel ratio control.
Implementation Method 1
an igniting device for igniting the fuel
Implementation Method 2
a fuel supply device for injecting fuel to be fed into the combustion chamber
Data Source
AI summary
An engine start control apparatus includes an intake air amount control device for controlling an amount of air supplied to a combustion chamber, a fuel supply device for injecting fuel to be fed into the combustion chamber, and an igniting device for igniting the fuel. The engine start control apparatus further includes an engine operation state detecting unit for detecting an operation state of the engine, an ignition timing retard angle processing unit configured to retard an ignition timing from a start ignition timing to an ignition timing for catalyst warming-up acceleration in response to detection that the engine operation state has shifted to an idling operation state, an intake control device operation unit for operating an intake control device so as to supply such an amount of intake air as to keep the idling operation state when the engine operation state has shifted to the idling operation state, and an injection fuel amount increasing unit for increasing an amount of fuel injected into a cylinder to be shifted to a combustion stroke so as to be combusted in the combustion stroke when the engine operation state has shifted to the idling operation state.