Double-Pipe Bayonet Joint with Sliding Alignment for Easy Insertion

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Solution Overview

Problem

The bayonet joint in cryogenic piping faces difficulty in inserting the male bayonet into the female bayonet due to a small clearance and long insertion length, making the process challenging.

Innovation Solution

A joint structure with a slide mechanism and positioning members, including a first and second positioning member, allows the male bayonet to be easily inserted into the female bayonet by aligning their center axes and using a slide mechanism to bring the double pipes closer, enabling easy insertion, particularly when one pipe is fixed and the other is movable.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the clearance between male bayonet and female bayonet is made small to ensure connection precision, then the connection reliability is improved, but the insertion difficulty increases due to long insertion length

Engineering Contradiction:
Improveconnection reliabilityVSAvoidinsertion ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by providing positioning members (positioning grooves and positioning protrusions) that pre-align the male and female bayonets before insertion. The positioning groove in the flange and positioning protrusion on the tubular body engage first to establish proper alignment, then guide the insertion process. This preliminary positioning action ensures that even with small clearance and long insertion length, the connection can be made reliably without excessive insertion difficulty.

Inventive Principle:
Principle #10Preliminary action

2Strength

If the insertion length is made long to ensure proper connection, then the connection strength is improved, but the insertion difficulty increases

Engineering Contradiction:
Improveconnection strengthVSAvoidinsertion ease
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent introduces positioning members as intermediary elements that facilitate the insertion process. The positioning groove and positioning protrusion act as mediators between the male and female bayonets, guiding them into proper alignment and enabling smooth insertion over the required long distance. This intermediary positioning mechanism ensures that the full insertion length is achieved for strong connection without making the insertion process excessively difficult.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If the clearance between male bayonet and female bayonet is reduced for precise alignment, then the alignment precision is improved, but the tolerance for misalignment during insertion decreases

Engineering Contradiction:
Improvealignment precisionVSAvoidalignment tolerance
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The positioning members perform preliminary alignment action before the actual insertion occurs. The positioning groove and positioning protrusion engage first to establish precise alignment, then guide the subsequent insertion. This preliminary positioning action provides both the desired alignment precision and accommodates reasonable misalignment tolerances during the insertion process, as the positioning members guide the components into proper alignment even if initial positioning is not perfect.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3444516B1Joint structure
Publication Date: 2021.03.17 KAWASAKI JUKOGYO KK
  • EP3444516B1 patent drawingFigure 1
  • EP3444516B1 patent drawingFigure 2
  • EP3444516B1 patent drawingFigure 3

AI summary

A joint structure connecting a first double pipe and a second double pipe to each other, includes a male bayonet provided at an end portion of one of the first double pipe and the second double pipe, the male bayonet including a first flange; a female bayonet provided at an end portion of the other of the first double pipe and the second double pipe, the female bayonet including a second flange to be fastened to the first flange; a first positioning member mounted on the first double pipe; a second positioning member mounted on the second double pipe, the second positioning member being positioned with respect to the first positioning member so that a center axis of the male bayonet and a center axis of the female bayonet conform to each other; and a slide mechanism which supports the first positioning member so that the first positioning member is slidable in an axial direction of the first double pipe or supports the second positioning member so that the second positioning member is slidable in an axial direction of the second double pipe.