Offset-Axis Hydrogen Pipe Joint for Early Shutoff on Detachment

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Solution Overview

Problem

Existing pipe joints for hydrogen gas filling systems fail to immediately shut off the gas flow path when the nozzle is detached from the filling apparatus, leading to the release of high-pressure hydrogen gas, known as outgas, which poses a safety risk.

Innovation Solution

A pipe joint design featuring cylindrical nozzle and filling apparatus side members with offset central axes and shutoff valves that open and close communication passages, utilizing conversion mechanisms to ensure rapid closure of the shutoff valves when the nozzle is separated, preventing outgas release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the plug is detached from the socket, then the nozzle can be separated from the filling apparatus, but high-pressure hydrogen gas flows out as outgas before the shutoff valve closes

Engineering Contradiction:
Improvenozzle separationVSAvoidoutgas release
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The socket side rod is positioned to contact the plug side valve stem or cover member before the plug is fully detached, triggering the shutoff valve to close in advance. This preliminary action prevents outgas release by closing the valve before the separation is complete, addressing the harmful effect while maintaining operational ease.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the socket side rod is placed on the plug side valve stem or cover member, then the shutoff valve can close earlier, but the structural complexity increases

Engineering Contradiction:
Improvevalve closure timingVSAvoidconversion mechanism structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The socket side rod combines multiple functions: it serves as both a structural support element and a trigger mechanism for the shutoff valve. By integrating the valve triggering function into the existing rod structure rather than adding a separate mechanism, the design achieves reliable early valve closure while minimizing structural complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the central axes of the passages are offset without intersecting, then the shutoff valve can close more effectively, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvevalve seat alignmentVSAvoidpassage axis offset accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The passages in the plug and socket are designed with intentionally offset central axes that do not intersect, creating an asymmetric configuration. This asymmetry ensures that when the plug is inserted, the valve stem contacts the rod at an optimal position that triggers effective valve closure. The asymmetric design is manufactured with standard tolerances, avoiding excessive precision requirements while achieving reliable valve seating.

Inventive Principle:
Principle #4Asymmetry

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 pipe joint effectively prevents the release of high-pressure hydrogen gas by ensuring the shutoff valve immediately closes when the nozzle is detached, significantly reducing the flow rate of outgas and enhancing safety.

Implementation Method 1

a valve element mounted to the other side of the socket side valve stem is held at a position separated from a socket side valve seat against elastic repulsive force of an elastic body on the socket side

Methodology Applied
Scientific EffectElastic repulsive force: Elasticity

Implementation Method 2

when the plug is detached from the socket, the shutoff valves close

Methodology Applied
Scientific EffectValve closure: Valve

Data Source

PatentEP4001725B1Pipe joint
Publication Date: 2023.01.18 TOKYO TATSUNO CO LTD
  • EP4001725B1 patent drawingFigure 1
  • EP4001725B1 patent drawingFigure 2
  • EP4001725B1 patent drawingFigure 3~4(C)

AI summary

To provide a pipe joint that can immediately shut off a hydrogen gas flow path at an initial stage when a plug (nozzle side member) comes out of a socket (filling apparatus side member) to prevent release of outgas. A pipe joint (100) of the present invention includes: a cylindrical nozzle side member (10) with a shutoff valve (5), in the cylindrical nozzle side member (10) being formed a passage (1A); and a cylindrical filling apparatus side member (20) with a shutoff valve (24), in the cylindrical filling apparatus side member (20) being formed a passage (21A), wherein when the nozzle side member (10) and the filling apparatus side member (20) are connected with each other, central axes of the passages (1A, 21A) of the nozzle side member (10) and the filling apparatus side member (20) do not form a same straight line, and the central axes of the passages (1A, 21A) are offset without intersecting, and the shutoff valves (5, 24) of the both members (10, 20) open to communicate the passages (1A, 21A) of the both members (10, 20) with each other, and when the nozzle side member (10) is separated from the filling apparatus side member (20) , the shutoff valves (5, 24) of the both members (10, 20) close.