High Pressure Tank Flange Corner Part Sealing

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Solution Overview

Problem

High pressure tanks face challenges in maintaining a sealing characteristic, especially at low pressures, due to gas accumulation between the liner and the mouth piece, leading to potential separation and leakage.

Innovation Solution

The design incorporates a corner part with a maximum height of 6.3 µm or less on the mouth piece, an inclined surface, and a hooking groove to enhance contact pressure and prevent gas entry into the annular groove, along with a manufacturing method involving insert molding and creep deformation to ensure a tight seal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the high pressure tank operates at low pressure, then the contact pressure on the interface between liner and mouth piece decreases, but the sealing characteristic deteriorates allowing gas to enter the interface

Engineering Contradiction:
Improvesealing characteristicVSAvoidcontact pressure on interface
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The corner part is formed in advance on the mouth piece before the liner is installed. This preliminary structural feature ensures that when the liner is pressed against the mouth piece, the corner part creates a localized high contact pressure region that prevents gas from entering the interface, even when the overall tank pressure is low.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Instead of relying on uniform contact pressure across the entire interface, the invention introduces a corner part that creates localized high contact pressure specifically at the critical sealing region. This local quality enhancement ensures effective sealing at the most vulnerable point (the corner) without requiring high overall contact pressure.

Inventive Principle:
Principle #3Local quality

2Reliability

If gas accumulates in the interface between liner and mouth piece, then the gas pressure in the interface increases, but the liner separates from the mouth piece

Engineering Contradiction:
Improvesealing characteristicVSAvoidseparation force on liner
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The corner part is designed to preemptively counteract the harmful effect of gas accumulation. By creating a localized high contact pressure region at the corner, it prevents gas from entering the interface in the first place, thereby eliminating the root cause of pressure buildup and subsequent liner separation.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The corner part transforms the potential harm of gas accumulation into a benefit by creating a pressure differential. The localized high contact pressure at the corner not only seals the interface but also helps to push accumulated gas back into the tank interior, converting the harmful gas pressure into a force that maintains sealing.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Stress or pressure

If the maximum height of the corner part is increased, then the contact pressure at the corner part increases, but the manufacturing precision requirement becomes more stringent

Engineering Contradiction:
Improvecontact pressure at corner partVSAvoidcorner part height control
Core Design Contradiction:
Stress or pressureVSManufacturing precision

Solution Approach 1:

The invention optimizes the corner part height parameter to a specific range (maximum 6.3 μm) that balances two competing requirements: generating sufficient localized contact pressure for effective sealing while remaining within achievable manufacturing tolerances. This parameter optimization resolves the contradiction between sealing performance and manufacturability.

Inventive Principle:
Principle #35Parameter changes

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

This configuration secures a high sealing characteristic even at low pressures, reduces gas entry into the annular groove, and prevents separation of the liner from the mouth piece, thereby maintaining the integrity of the high pressure tank.

Implementation Method 1

a temperature and a pressure of a fluid making contact with an inner peripheral surface of the liner are maintained to respective predetermined values or more so that the liner flows to fill the gap

Methodology Applied
Scientific EffectCreep deformation: Creep

Data Source

PatentEP3128221B1High pressure tank, manufacturing method of high pressure tank, and inspection method of sealing characteristics
Publication Date: 2019.10.23 TOYOTA JIDOSHA KK
  • EP3128221B1 patent drawingFigure 1
  • EP3128221B1 patent drawingFigure 2
  • EP3128221B1 patent drawingFigure 3

AI summary

An opening-side flange (120) includes a connecting surface including an inclined surface (143), a corner part (145), and an annular groove (147) on a bottom-face-(140) side. A conical surface part (143b) of the inclined surface is a conical surface of a truncated cone, and is inclined such that a radially outer end thereof approaches an opening side. The corner part (145) is a part as a corner formed between the inclined surface (143) and the annular groove (147), and functions as a sealing surface with the liner (20). The annular groove (147) is a part that connects the inclined surface (143) to an outer surface part (149), and is a part that is hollowed toward the opening side relative to the inclined surface (143).