Fuel Injector Diagnosis Using Single Common Rail Sensor
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Solution Overview
Problem
In multi-cylinder engines, the existing diagnostic systems require a fuel pressure sensor for each fuel injector, increasing costs and complexity.
Innovation Solution
A diagnostic apparatus that uses a single fuel pressure sensor in a fuel injection system to monitor pressure changes in adjacent fuel injectors, determining if a malfunction occurs by detecting specified pressure increases, allowing for diagnosis without additional sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fuel pressure sensor is provided to each fuel injector, then the diagnosis accuracy of continuous injection malfunction is improved, but the cost and device complexity increase
Solution Approach 1:
The patent merges the diagnostic function for multiple fuel injectors into a single sensor system. By placing one fuel pressure sensor in the common rail and using it to monitor pressure changes caused by any injector's operation, the system combines multiple diagnostic functions into a single sensor setup, thereby reducing the number of sensors while maintaining diagnosis capability for all injectors
Solution Approach 2:
The single fuel pressure sensor in the common rail serves multiple functions: it monitors fuel pressure for any injector at any time, enabling diagnostic capability for all fuel injectors simultaneously. This universal sensor position allows the system to detect continuous injection malfunctions in any injector by observing pressure changes in the common rail, making the sensor multi-functional rather than injector-specific
2Measurement precision
If a fuel pressure sensor is provided to each fuel injector, then the measurement precision of fuel pressure is improved, but the manufacturing cost increases
Solution Approach 1:
The patent combines multiple fuel pressure measurement functions into a single sensor installation. Instead of installing separate sensors for each injector, the system merges all measurements into one common rail sensor position, reducing component count and manufacturing complexity while maintaining the ability to measure fuel pressure effects from any injector
Solution Approach 2:
The common rail acts as an intermediary medium that transmits pressure changes from any injector to the single fuel pressure sensor. This intermediary approach allows indirect measurement of fuel pressure effects from multiple injectors through the common rail pressure variations, eliminating the need for direct sensor installation at each injector while preserving measurement capability
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
Reduces the number of fuel pressure sensors needed while effectively diagnosing continuous injection malfunctions in fuel injectors, maintaining accurate fuel injection control and reducing costs.
Implementation Method 1
a first fuel pressure sensor is disposed in the first fuel pressure passage for detecting a fuel pressure in the first fuel passage
Implementation Method 2
this fuel-pressure-increase generated in the second fuel passage is propagated to the first fuel passage through the accumulator
Data Source
AI summary
Based on a detection signal of a fuel pressure sensor provided in a first fuel injector, an ECU determines whether a fuel pressure in a first fuel injector is increased over a specified amount when a second fuel injector provided with no fuel pressure sensor terminates a fuel injection. When the ECU determines that the fuel pressure in the first fuel injector is increased over a specified amount, it is diagnosed that the second fuel injector does not have a malfunction of continuous injection.