Spoiler Droop Mechanical Feedback for Failure-Safe Retraction
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Solution Overview
Problem
Aircraft spoiler control systems face challenges in maintaining position detection and preventing damage during electrical or hydraulic failures, particularly when the spoiler is in the droop function, leading to potential interference with the wing flap and panel damage.
Innovation Solution
A mechanical device is integrated with the hydraulic actuator to detect the spoiler's position and control load application, using an anti-extension valve and pressure relief mechanism to prevent extension during failures, allowing the spoiler to retract safely and avoid overlap with the wing flap.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the spoiler is actuated using a negative stroke (droop function) to lower the spoiler relative to the wing, then the spoiler can close air gaps between the wing flap and spoiler, but the risk of interference with the wing flap and panel damage increases
Solution Approach 1:
The patent applies preliminary anti-action by incorporating a mechanical feedback device that detects spoiler position and automatically activates a pressure relief valve when the spoiler approaches the wing flap during droop function. This preemptive mechanism prevents interference and potential panel damage before it can occur, rather than relying on post-failure correction
Solution Approach 2:
The patent implements feedback through a mechanical device connected to the piston rod that detects spoiler position and provides mechanical feedback to control the pressure relief valve. This closed-loop system continuously monitors spoiler position and adjusts hydraulic pressure accordingly, preventing harmful interference while maintaining reliable position control during droop function
2Reliability
If electrical power is lost during droop function operation, then the hydraulic actuator loses active control, but mechanical feedback can maintain position detection and safety
Solution Approach 1:
The patent replaces electrical position detection systems with a mechanical feedback device that uses mechanical linkages and levers to detect spoiler position and control the pressure relief valve. This mechanical substitution ensures position detection and safety control remain functional even when electrical power is lost during droop operation
Solution Approach 2:
The mechanical feedback device is self-actuating and does not require external electrical power. It automatically detects spoiler position through mechanical movement and triggers the pressure relief valve when necessary, providing autonomous safety functionality that serves itself without external energy input
3Stability of the object's composition
If hydraulic pressure is increased to maintain spoiler position during failures, then position stability improves, but the risk of damage to spoiler and wing flap increases
Solution Approach 1:
The patent dynamically changes hydraulic pressure parameters by using the pressure relief valve to reduce pressure when the spoiler approaches the wing flap during droop function. This parameter adjustment maintains position stability when safe while preventing damage when the spoiler nears the flap, adapting pressure levels to real-time positional conditions
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 system ensures safe retraction of the spoiler during failures, preventing damage to both the spoiler and wing flap by limiting load application and maintaining position detection, even in the absence of electrical power, and adjusting pressure thresholds to avoid damage during hydraulic failures.
Implementation Method 1
upon loss of said power, said pressure relief valve may reduce or limit said load applied to said piston rod
Implementation Method 2
an anti-extension valve that is operably connected to said hydraulic actuator and configured to prevent the piston rod from moving into the extended position upon loss of said power
Data Source
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AI summary
A system for detecting and controlling the position of a spoiler (80) of an aircraft wing is described herein comprising: a hydraulic actuator (40) having a piston rod (43) operably connected to the spoiler (80), the piston rod (43) being moveable between a retracted position, a neutral position and an extended position; and means for providing power to said hydraulic actuator (40); and a mechanical device (50) for detecting whether the piston rod (43) is in the retracted position, the neutral position or the extended position; and means (60), operatively connected to the mechanical device (50), that is configured to provide a change in a load applied to said hydraulic actuator (43), wherein said means (60) is configured to change said load based on whether said piston rod (43) is detected as being in said retracted position or said extended position.