Engine Idle Stop Fuel Injection Control via Crank Angle Sensor
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Solution Overview
Problem
The existing engine control device for saddle-straddling type motor vehicles may generate spark discharge at incorrect times due to crank angle detection device failures, leading to inefficient fuel combustion and catalyst deterioration during idle stop and re-start operations.
Innovation Solution
An engine system with a controller that manages idle stop and normal modes, using a first detection subject and detector to maintain fuel-air mixture in the combustion chamber during idle stop and prevent fuel injection upon abnormality detection, ensuring quick re-start and minimizing fuel wastage and catalyst deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the crank angle detection device is used to detect the rotation position of the crank shaft, then the engine can be quickly started by generating a first explosion, but the spark discharge may be generated at a wrong time point when the device fails, leading to fuel wastage and catalyst deterioration
Solution Approach 1:
The system performs preliminary action by maintaining a fuel-air mixture in the combustion chamber during idle stop mode before re-start. This pre-prepared mixture allows the engine to quickly restart without needing to wait for fuel injection and mixing, thus improving productivity while reducing the risk of incorrect spark discharge timing.
Solution Approach 2:
The controller continuously monitors the operation state of the detection device and provides feedback to adjust fuel injection timing and idle stop mode operation. When abnormality is detected, the controller stops fuel injection during idle stop, preventing harmful uncombusted mixture exhaust. This feedback mechanism resolves the contradiction by maintaining reliability while preserving quick start capability.
2Productivity
If fuel is injected during idle stop mode to maintain fuel-air mixture in combustion chamber, then quick re-start is achieved, but fuel is wasted and catalyst deteriorates when detection device fails
Solution Approach 1:
The system dynamically adjusts fuel injection strategy based on real-time detection of abnormality in the crank angle detection device. During normal operation, fuel is injected during idle stop to enable quick re-start. When abnormality is detected, fuel injection during idle stop is stopped. This dynamic adaptation resolves the contradiction between quick re-start capability and fuel conservation.
Solution Approach 2:
The controller changes the operational parameters of the fuel injection system based on detection device status. When abnormality is detected, the parameter change involves stopping fuel injection during idle stop mode, thereby preventing fuel wastage and catalyst deterioration while maintaining the ability to restart the engine.
3Loss of energy
If the engine is automatically stopped during temporary stops, then fuel efficiency is improved, but the re-start operation becomes frequent and requires quick response
Solution Approach 1:
The system performs preliminary action by maintaining a ready-to-combust fuel-air mixture in the combustion chamber during idle stop mode. This pre-prepared state allows the engine to restart immediately when needed, thus improving re-start response time without compromising the fuel efficiency benefits of automatic idle stop during temporary stops.
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 system improves fuel efficiency and prevents catalyst deterioration by maintaining the fuel-air mixture during idle stop and ensuring proper ignition upon re-start, while avoiding uncombusted mixture exhaustion.
Implementation Method 1
The electromagnetic pickup is provided in the vicinity of the outer peripheral surface of the rotor, and generates a crank angle pulse signal indicating that the front end and the rear end of each convex portion has passed through the vicinity at the time of rotation of the rotor.
Implementation Method 2
at the time of the engine start-up, spark discharge (the ignition) of the ignition plug is generated at a time point at which the rear end of the convex portion that is to be detected subsequently to the reference convex portion is detected
Implementation Method 3
a fuel injection device that injects fuel into an intake passage that leads air into a combustion chamber of a cylinder and produces a fuel-air mixture
Implementation Method 4
the fuel-air mixture compressed in a first compression stroke after a change from the idle stop mode to the normal mode
Data Source
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AI summary
An engine is controlled in a normal mode or an idle stop mode. The ignition of a fuel-air mixture is performed in the normal mode, and the ignition of the fuel-air mixture is not performed in the idle stop mode. A detection subject that is rotated together with a crank shaft is provided at the crank shaft. At the time of the re-start of an engine, the ignition of the fuel-air mixture compressed in the first compression stroke is performed based on the detection of the detection subject by a reference angle sensor. When an operation abnormality of the reference angle sensor is not detected, the injection of the fuel is performed in a plurality of cycles right before the rotation of the crank shaft is stopped in the idle stop mode. When the operation abnormality of the reference angle sensor is detected, the injection of the fuel is not performed in the idle stop mode.