Fuel Injector Damping Adjustment Valve for Injection Control
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Solution Overview
Problem
Modern fuel injectors face challenges in precisely controlling the injection of both small and large fuel quantities, particularly in varying engine loads, due to the complexity of their rapidly moving parts and the need for precise control over fuel quantity, which affects emissions and fuel efficiency.
Innovation Solution
A fuel injector system with a damping adjustment valve that moves between higher and lower damping positions to selectively vent a spring chamber, allowing for hydraulic actuation and varying fuel pressure to control the damping of the nozzle check, enabling precise control over fuel injection by adjusting the damping based on fuel pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fuel injector uses numerous rapidly moving parts to control fuel injection, then the ability to precisely control injection quantity is improved, but the device complexity increases
Solution Approach 1:
The patent extracts the damping control function from the complex valve train mechanism and implements it through a separate damping adjustment valve that controls venting of the spring chamber. This separates the fuel injection control function from the damping control function, allowing precise injection quantity control while simplifying the overall system architecture by dedicating specific components to specific functions.
Solution Approach 2:
The damping adjustment valve acts as an intermediary component between the fuel pressure system and the nozzle check spring chamber. By controlling the venting of fuel pressure from the spring chamber, it mediates the relationship between fuel pressure and nozzle check movement, enabling precise control of injection quantity without requiring complex direct mechanical linkages.
2Reliability
If a fuel injector is designed for controlled closing velocity of nozzle check, then the reliability of fuel injection is improved, but the device complexity increases
Solution Approach 1:
The patent uses hydraulic damping control by venting fuel pressure from the spring chamber through a controlled orifice. The damping adjustment valve regulates the flow of fuel pressure through this orifice, creating a hydraulic damping effect that controls the closing velocity of the nozzle check. This replaces complex mechanical valve train components with a hydraulic control mechanism, improving reliability while managing complexity.
3Measurement precision
If a fuel injector uses a damping adjustment valve to control spring chamber venting, then the precision of injection quantity control is improved, but the device complexity increases
Solution Approach 1:
The damping adjustment valve changes the parameter of spring chamber venting by controlling the opening area of the vent orifice. By adjusting the damping adjustment valve, the venting rate of fuel pressure from the spring chamber is modified, which directly affects the closing velocity of the nozzle check and thus the injection quantity. This parameter control approach enables precise injection control through a single adjustable parameter rather than complex multi-component mechanisms.
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 solution allows for precise control over fuel injection, improving fuel efficiency and reducing emissions by enabling the injection of both small and large fuel quantities with reduced 'turn-down' effect, thereby enhancing the reliability and repeatability of fuel injection across different engine loads.
Implementation Method 1
a check biasing spring within the spring chamber and biasing the direct-operated nozzle check toward the closed position
Implementation Method 2
A fuel system in a compression-ignition engine can be a complex apparatus. Most modern fuel injectors include numerous rapidly moving parts that are electrically or hydraulically actuated
Implementation Method 3
a damping adjustment valve movable between a higher damping position blocking the second vent, and a lower damping position where the second vent is open
Data Source
AI summary
A fuel injector for a fuel system in an internal combustion engine includes an injector housing, a direct-operated nozzle check movable within the injector housing, a check biasing spring within a spring chamber and biasing the nozzle check toward the closed position. The injector housing defines a damping control space, an always-open vent from the spring chamber to the damping control space, and a second vent from the spring chamber to the damping control space. The fuel injector further includes a hydraulically actuated damping adjustment valve movable responsive to a pressure of fuel supplied to the fuel injector between a higher damping position blocking the second vent, and a lower damping position where the second vent is open.