Fuel Injector Isolation Valves for Cross-Talk Attenuation
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Solution Overview
Problem
In internal combustion engine fuel systems, particularly in compression ignition diesel engines, fluid pressure pulses from one fuel injector can cause cross-talk and performance degradation by opening injection control valves in other injectors, due to unobstructed communication through a common drain conduit.
Innovation Solution
The implementation of isolation valve assemblies positioned between each fuel injector and the common drain conduit, which include a movable isolation valve member and a biaser, to block or allow fluid communication between the injection control valve assembly and the common drain conduit, thereby attenuating or eliminating fluid pressure pulses and preventing cross-talk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common drain conduit is used to receive drained actuating fluid from multiple fuel injectors, then the system structure is simplified and fluid drainage is efficient, but fluid pressure pulses from one injector can cause cross-talk and open injection control valves in other injectors, degrading system performance
Solution Approach 1:
The common drain conduit is segmented into multiple isolated sections, with each section serving a specific fuel injector. Isolation valves are positioned between each injector and the common drain conduit to create separate drainage paths. This segmentation prevents fluid pressure pulses from propagating between injectors while maintaining the benefits of a structured drainage system.
Solution Approach 2:
Isolation valves are introduced as intermediary components between each fuel injector and the common drain conduit. These valves act as mediators that control fluid communication, allowing drained actuating fluid to pass through during normal operation while blocking pressure pulses that could cause cross-talk between injectors.
2Reliability
If isolation valve assemblies are positioned between each fuel injector and common drain conduit to block fluid pressure pulses, then cross-talk between injectors is eliminated and injection control reliability is improved, but the device complexity and number of components increase
Solution Approach 1:
The isolation valve assembly merges multiple functions into a single integrated component: it provides isolation between injectors, controls fluid drainage, and maintains system pressure when closed. By combining these functions, the patent reduces the overall component count compared to using separate isolation valves, drainage control mechanisms, and pressure regulation devices.
Solution Approach 2:
The isolation valve assembly is designed as a universal component that can be installed between any fuel injector and the common drain conduit. Each assembly performs multiple functions: isolating pressure pulses, controlling fluid drainage timing, and maintaining system integrity. This multi-functionality reduces the need for additional specialized components.
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 isolation valve assemblies effectively reduce or eliminate cross-talk between fuel injectors, enhancing the performance and reliability of the fuel system by blocking incoming pulses and maintaining fluid sealing, thus improving the system's operational stability and extending service life.
Implementation Method 1
a biaser biasing the isolation valve member toward the closed position
Implementation Method 2
movable between a closed position blocking the injection control valve assembly in the one of the plurality of fuel injectors from the common drain conduit, and an open position
Data Source
AI summary
A fuel system includes a plurality of fuel injectors connected to a common drain conduit, and a plurality of isolation valve assemblies each positioned fluidly between the common drain conduit and one of the plurality of fuel injectors. Each isolation valve assembly includes a valve member movable between a closed position to block an injection control valve assembly in the fuel injector from the common drain conduit, and an open position, and a biaser biasing the isolation valve member toward the closed position such that fuel injectors are isolated from fluid pressure pulses produced by nozzle check actuation to limit cross-talk among the fuel injectors.