Vehicular Tube Fitting Assembly With Radial Compression Locking

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Solution Overview

Problem

Existing fitting assemblies for vehicular tubes fail to effectively prevent leaks at high fluid pressures, particularly in applications involving pressurized fluids like hydrogen supply, as they allow fluid to escape through gaps between joined parts.

Innovation Solution

A fitting assembly with a bushing element that exerts radial compression on the first tube element, combined with a locking element to limit relative movements and sealing elements to minimize leaks, ensuring a secure mechanical and fluid-dynamic connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional fitting assemblies are used to connect tube elements, then mechanical connection is achieved, but fluid leakage occurs at high pressures

Engineering Contradiction:
Improvefluid sealingVSAvoidfluid leakage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The fitting assembly is divided into distinct functional segments: a compression fitting portion for mechanical connection, sealing elements positioned at potential leakage paths, and a locking portion to maintain compression. This segmentation allows each component to address specific sealing requirements at different locations where leaks could occur.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compression fitting portion is designed to pre-compress the sealing elements against the tube elements before the locking portion is engaged. This preliminary compression action ensures that sealing surfaces are already under sufficient pressure to prevent fluid leakage at high operating pressures, eliminating the need for additional compression during operation.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If simple mechanical connections are used, then ease of assembly is improved, but leak prevention capability deteriorates

Engineering Contradiction:
Improveassembly speedVSAvoidleak prevention
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention merges multiple functions into a single integrated fitting assembly: mechanical connection through the compression fitting portion, sealing through integrated sealing elements, and locking through the locking portion. This combination allows the assembly to achieve both ease of operation and reliable leak prevention without requiring separate components or complex assembly procedures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The fitting assembly is designed as a multi-functional component that simultaneously provides mechanical support, fluid sealing, and positional locking. The compression fitting portion serves both structural and sealing functions, while the locking portion maintains both mechanical and sealing integrity, making the assembly universally applicable to various tube connections requiring high-pressure sealing.

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

3Reliability

If multiple sealing components are added to prevent leaks, then sealing reliability is improved, but device complexity increases

Engineering Contradiction:
Improvesealing performanceVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Sealing elements are strategically positioned only at specific locations where fluid leakage is most likely to occur, such as the interface between the compression fitting portion and tube elements. This localized sealing approach provides high sealing reliability at critical points without adding sealing components to all surfaces, thereby avoiding unnecessary complexity.

Inventive Principle:
Principle #3Local quality

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 assembly effectively transfers pressurized fluids while minimizing leaks, providing a simple and fast connection that maintains fluid integrity under high pressure conditions.

Implementation Method 1

a bushing element (7), which exerts a radial compression on the first tube element (1) with respect to the longitudinal axis (A)

Methodology Applied
Scientific EffectRadial compression: Compression

Implementation Method 2

a locking element (8), which is shaped to engage the seat (6) so as to prevent and/or limit the relative movements between the second tube element (2) and the fitting element (3)

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentEP4337881B1Improved fitting assembly for vehicular tubes and hydraulic assembly comprising such fitting assembly
Publication Date: 2025.08.27 ERRECINQUE
  • EP4337881B1 patent drawingFigure 1
  • EP4337881B1 patent drawingFigure 2~3B
  • EP4337881B1 patent drawingFigure 4~5

AI summary

A fitting assembly (10) for fitting a first tube element (1) to a second tube element (2) comprising a fitting element (3) defining a longitudinal axis (A) and comprising a male portion (4) adapted to engage the first tube element (1) and a female portion (5) adapted to be engaged by the second tube element (2); the female portion (5) being opposite to the male portion (4) along the longitudinal axis (A) and further defining a seat (6); a bushing element (7) adapted to be arranged radially external with respect to the male portion (4) and the first tube element (1) and to exert a radial compression on the first tube element (1); and a locking element (8) adapted to limit the relative movements of the second tube element (2) with respect to the fitting element (3) when it engages the seat (6).