Fuel Filter Malfunction Detection via Differential Pressure
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Solution Overview
Problem
Existing fuel supply systems without electric pumps face challenges in detecting fuel filter malfunctions, as they rely on electric current or rotation speed, which are not applicable in systems without electric pumps, leading to inefficiencies in filtration and pressure loss.
Innovation Solution
A fuel-filter malfunction detection device that utilizes a discharge control portion to adjust the high-pressure pump's discharge quantity and a pressure obtaining portion with a pressure sensor to determine fuel filter malfunctions based on fuel pressure, allowing for accurate detection without additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If electric current value or rotation speed of electric pump is used to detect fuel filter malfunction, then malfunction detection is enabled, but the method cannot be applied to fuel supply systems without electric pumps
Solution Approach 1:
The patent replaces electrical detection methods (electric current, rotation speed) with a mechanical/physical detection method using fuel pressure measurement. The pressure sensor measures fuel pressure upstream of the high-pressure pump, providing a universal detection method that works regardless of whether an electric pump is present in the system.
Solution Approach 2:
The fuel pressure-based detection method serves as a universal solution that can be applied to both systems with electric pumps and systems without electric pumps. The pressure sensor and control unit work together to detect fuel filter clogging in various fuel supply system configurations, making the detection method adaptable and versatile.
2Measurement precision
If fuel pressure measurement is used to detect fuel filter malfunction, then detection accuracy is improved by reducing noise, but additional pressure sensors may increase device complexity
Solution Approach 1:
The system utilizes the existing fuel pressure sensor (already present in the fuel supply system for other control functions) to detect fuel filter malfunctions. The control unit processes the pressure signal to determine filter clogging, allowing the system to perform self-diagnosis without requiring separate dedicated detection sensors, thus avoiding increased device complexity.
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 effective detection of fuel filter malfunctions by measuring differential pressure, reducing noise and erroneous determinations, and maintaining target fuel injection quantities, applicable to various vehicle sizes and systems without electric pumps.
Implementation Method 1
a pressure sensor arranged downstream of the high-pressure pump
Data Source
AI summary
A fuel-filter malfunction detection device detects a clogging of a fuel filter when specified conditions are satisfied. In a clogging detection, a command discharge quantity to a high-pressure pump is increased more than a total of a fuel injection quantity and a leakage of the fuel supply system while a pressure-reducing valve is closed. When the fuel filter is clogged, a discharge quantity of the high-pressure pump is decreased relative to the command discharge quantity and a differential pressure is generated between an estimated common-rail pressure and an actual common-rail pressure. When an integrated moving average of the averages of the differential pressure is greater than or equal to a specified value, an ECU determines that the fuel filter has a malfunction. Then, a malfunction flag is turned ON.