Fuel Injection Controller Interference Period Detection
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Solution Overview
Problem
Cylinder-direct injection engines face challenges in accurately detecting and adjusting for interference periods, where fuel injection overlaps with intake valve opening, leading to reduced engine output and emission issues due to variations in valve mechanisms and injector alignment over time.
Innovation Solution
A fuel injection controller with an air-fuel ratio sensor and interference period detection unit that shifts the injection period to avoid overlap with the interference period, using the air-fuel ratio variations detected by the sensor to precisely determine the actual interference period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the injection period is changed and corrected to avoid the interference period, then fuel adhesion to the intake valve is reduced, but the interference period may still overlap with the injection period due to variations in valve mechanism and injector alignment over time
Solution Approach 1:
The system uses a feedback mechanism where the air-fuel ratio sensor continuously monitors the actual interference period, and the controller adjusts the injection timing based on this feedback. The interference period detection unit detects variations in the interference period by monitoring air-fuel ratio changes, and the controller corrects the injection period accordingly to maintain avoidance of the interference period.
Solution Approach 2:
The patent replaces mechanical assumptions about fixed interference periods with a sensor-based detection system. Instead of relying on predetermined mechanical timing, the system uses the air-fuel ratio sensor to detect the actual interference period caused by fuel adhesion, substituting mechanical timing calculations with sensor-based measurement and control.
2Device complexity
If the injection period is fixed, then the control system is simple, but fuel may adhere to the intake valve when the interference period shifts due to valve mechanism aging or injector alignment variation
Solution Approach 1:
The system transitions from a static, fixed injection period to a dynamic, adaptive injection period. The interference period detection unit continuously monitors changes in the interference period caused by valve mechanism aging or injector alignment variation, and the controller dynamically adjusts the injection timing to maintain optimal fuel delivery while avoiding the interference period.
Solution Approach 2:
The system performs self-diagnosis and self-correction by using the air-fuel ratio sensor to detect actual interference period variations and automatically adjusting the injection timing. The controller monitors its own performance and corrects any deviations without external intervention, enabling the system to compensate for aging and alignment variations autonomously.
3Productivity
If the injection period is adjusted to avoid the interference period, then engine output is maintained, but emission may deteriorate due to incomplete fuel delivery
Solution Approach 1:
The system applies partial action by injecting fuel in a controlled manner that partially overlaps with the interference period when necessary. The interference period detection unit identifies when the interference period shifts, and the controller adjusts the injection timing to include partial overlap, allowing sufficient fuel to reach the cylinder while minimizing adhesion to the intake valve, thus balancing engine output and emission control.
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
Enables accurate detection and adjustment of the interference period, ensuring proper fuel supply to the cylinders, preventing engine output reduction and emission deterioration even as interference periods shift over time.
Implementation Method 1
an air-fuel ratio sensor disposed in an exhaust passage of the engine, and an interference period detection unit detecting an interference period of a crank angle range in which the fuel injected from the fuel injector is adhered to an opened intake valve
Data Source
AI summary
In a fuel injection controller that controls a fuel injection device that injects fuel directly into cylinders of an engine, a unit that detects an interference period gradually shifts an injection period of fuel from the fuel injector from a first period during which the injection period does not overlap with an initial value of the interference period, and is distant from the initial value by a given value or larger toward a second period during which the injection period overlaps with the initial value of the interference period. Then, the fuel injection controller detects an actual interference period according to a variation of an air-fuel ratio (A/F value) detected by an air-fuel ratio sensor toward lean.