Fuel Injection Controller Valve Timing Control
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Solution Overview
Problem
Conventional fuel injection controllers experience deteriorated fuel injection accuracy due to temperature characteristics, particularly in multi-stage injections, where the valve opening start time and period are influenced by temperature-related changes in coil current and electromagnetic force, leading to inaccuracies in fuel injection.
Innovation Solution
A fuel injection controller that applies a voltage to increase the coil current to a first target value and then holds it at that value, ensuring the electromagnetic attracting force is greater than the required valve-opening force, thereby minimizing the impact of temperature characteristics on the valve opening time and period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the coil current is increased to reach the target peak value quickly, then the valve opening start time is improved, but the temperature characteristic influence worsens because the current increasing ratio varies with temperature
Solution Approach 1:
The patent divides the coil current control into two distinct phases: a current increase control phase (from zero to first target value) and a current hold control phase (maintaining at first target value). This segmentation allows the system to achieve rapid valve opening through controlled current increase while maintaining stable electromagnetic force during the injection period, thereby reducing the impact of temperature characteristics on fuel injection accuracy.
Solution Approach 2:
The patent dynamically adjusts the coil current control strategy based on the injection phase. During the current increase control period, the system allows rapid current rise to ensure timely valve opening. During the current hold control period, the system maintains a constant first target value regardless of temperature variations, stabilizing the electromagnetic force and reducing timing deviations in multi-stage injections.
2Manufacturing precision
If the coil current is held at a constant value, then the fuel injection accuracy is improved, but the valve opening speed is reduced
Solution Approach 1:
The patent applies preliminary action by establishing the first target value (higher than conventional hold values) before the injection phase begins. The current increase control phase rapidly builds up the coil current to this elevated first target value, ensuring the valve opens quickly. Once reached, the current hold control phase maintains this value to provide sufficient electromagnetic force for accurate fuel injection, thus achieving both fast valve opening and high injection accuracy.
3Reliability
If the target peak value is set high to ensure maximum valve lift, then the valve opening reliability is improved, but the energy consumption increases
Solution Approach 1:
The patent changes the control parameter strategy by introducing a first target value that is higher than the conventional hold value but controlled only during the increase phase. The system applies voltage to rapidly increase current to this higher first target value for reliable valve opening, then maintains it during the hold phase. This parameter optimization ensures sufficient electromagnetic force for reliable valve opening while controlling energy consumption through precise timing of the high-current phase.
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 the robustness of the control system against temperature characteristics, maintaining consistent fuel injection accuracy and reducing energy consumption by optimizing the electromagnetic force and current management.
Implementation Method 1
When the coil is energized, the coil generates an electromagnetic force which lifts up a valve body to inject a fuel
Data Source
AI summary
A fuel injection controller includes a current-increase control portion applying a voltage to the coil so that the coil current is increased to a first target value, and a current-hold control portion applying the voltage to the coil so that the increased coil current is held at the first target value. A maximum electromagnetic attracting force to start a valve opening is referred to as a required valve-opening force. A saturated electromagnetic attracting force by the coil current of the first target value is referred to as a static attracting force. The first target value is established in such a manner that the static attracting force is greater than the required valve opening force.