Aircraft Fluid Tank Filling Device with Float and Non-Return Mechanism

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Solution Overview

Problem

Existing fluid tank filling devices on aircraft face challenges in preventing overfilling and unintended fluid leakage, particularly due to vibrations and air turbulence, and require precise positioning to ensure the fluid level does not exceed a predetermined level without automatic non-return functionality.

Innovation Solution

A filling device utilizing a float mechanism that automatically adjusts to prevent overfilling by blocking the filling pipe when the fluid level reaches a predetermined height, combined with a non-return system using a ball and spring mechanism or pressure difference to prevent fluid leakage, allowing for simple and effective operation without specific height requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the filling device is placed at the maximum height of fluid in the reservoir to prevent overfilling, then the overfilling prevention function is improved, but the device complexity increases and installation becomes more difficult

Engineering Contradiction:
Improveoverfilling preventionVSAvoidfilling device positioning
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A float mechanism is introduced as an intermediary element that automatically rises with the fluid level and mechanically blocks the filling pipe outlet when the maximum level is reached. This float acts as a mediator between the fluid level and the filling flow control, eliminating the need for complex positioning systems or electronic sensors.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The filling device utilizes the fluid itself to activate the stopping mechanism. As the fluid level rises, the float is buoyed upward by the fluid pressure and automatically occludes the filling pipe outlet. The system serves itself by using the fluid's own pressure and level to trigger the shutdown, without requiring external control systems.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If a manual plug is used to close the reservoir, then the ease of operation is improved, but the reliability of preventing unintended fluid leakage deteriorates due to vibrations and air turbulence

Engineering Contradiction:
Improvemanual pluggingVSAvoidfluid leakage prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system automatically closes the filling pipe outlet using the float mechanism that rises with the fluid level. When the fluid reaches the maximum level or when fluid tries to escape due to vibrations, the float automatically occludes the outlet, providing self-service protection without requiring manual intervention.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The float mechanism is positioned to preemptively block the filling pipe outlet before unintended fluid leakage can occur. During vibrations or turbulence, the float maintains readiness to occlude the outlet, preventing harmful fluid escape before it can happen.

Inventive Principle:
Principle #9Preliminary anti-action

3Reliability

If the filling device is designed with automatic non-return functionality, then the reliability of preventing fluid leakage is improved, but the device complexity increases

Engineering Contradiction:
Improvefluid leakage preventionVSAvoidfilling device structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The float mechanism serves dual functions: it indicates the fluid level and simultaneously acts as the stopping mechanism by occluding the filling pipe outlet. This merging of level indication and flow control functions into a single element simplifies the overall device structure while maintaining reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The float element performs multiple functions within the filling device: it tracks the fluid level, triggers the stopping mechanism, and provides non-return functionality. This multi-functionality reduces the need for separate components, thereby reducing device complexity while improving reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution ensures reliable prevention of overfilling and fluid leakage, providing a safe and efficient filling process by automatically interrupting fluid entry and maintaining the non-return function, even under varying aircraft conditions.

Implementation Method 1

Naturally, the first float is moved by the buoyancy force which applies to it when it is immersed in the fluid contained in the tank.

Methodology Applied
Scientific EffectBuoyancy force: Archimedes' Principle (Buoyancy)

Implementation Method 2

The holding system can be configured to implement a restoring force chosen from the group comprising a gas pressure, an elastic force for example of a spring

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 3

the second plug can be arranged such that, if a pressure in the tank is greater than a pressure outside the tank, the pressure difference between the tank and the outside of the tank maintains the second plug in the closed position

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP2872401B1Filling device for fluid tank
Publication Date: 2019.02.13 SAFRAN HELICOPTER ENGINES
  • EP2872401B1 patent drawingFigure 1~2
  • EP2872401B1 patent drawingFigure 3~4
  • EP2872401B1 patent drawingFigure 5~6

AI summary

Filling device (100, 200, 300, 400, 500) for fluid tank (10) comprising a filling pipe (102, 402, 502), a first stopper (110, 210, 420, 510) to prevent the overfilling of the tank, and a second stopper (120, 220, 320, 420, 520) for preventing unwanted discharge of fluid from the tank; a first float (110, 210, 410, 510) mechanically connected to the first stopper so that the first float, by positioning itself in a predetermined position, closes the first stopper; and a system (122, 222, 422) for retaining the second stopper which, when fluid leaves the tank, closes the second stopper and, when the fluid enters the tank, opens the second stopper. The retaining system constantly urges the second stopper because when the device is in a position under the effect of the weight of a heavy element (430, 520), the retaining system tends constantly to keep the second stopper (420, 520) in its closed position.