Fuel Cell Separator Bead Sealing via Simultaneous Preload

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Solution Overview

Problem

Fuel cell separators face challenges in maintaining stable sealing performance due to dimensional variations in stopper bead portions, leading to potential plastic deformation and impaired sealing function under varying loads.

Innovation Solution

A method of manufacturing a separator that involves forming metal separators with protruding sealing and stopper bead portions, joining them with seal members, and applying preload to both bead seal and stopper sections to achieve desired sealing surface pressure without inducing plastic deformation, even with load variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If preload is applied only to the bead seal section, then sealing performance is improved, but dimensional variations in stopper bead portions cause plastic deformation and unstable sealing under load variations

Engineering Contradiction:

Improvesealing performanceVSAvoiddimensional variation of stopper bead portions

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The invention applies preload to both the bead seal section and stopper sections before the separator is assembled into the fuel cell. This preliminary action pre-deforms the bead seal section to improve sealing performance while simultaneously pre-positioning the stopper bead portions to reduce dimensional variations, preventing plastic deformation under subsequent load variations

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention segments the preload application into two distinct functional zones: the bead seal section receives preload to enhance sealing, while the stopper sections receive preload to control dimensional stability. This segmentation allows each portion to be optimized independently for its specific function, resolving the contradiction between sealing performance and dimensional precision

Inventive Principle:

Principle #1Segmentation

2Reliability

If stopper bead portions have high dimensional accuracy, then sealing stability is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvesealing stabilityVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of requiring high manufacturing precision for stopper bead portions, the invention applies preliminary preload to pre-position these portions, achieving dimensional stability through post-forming adjustment rather than tight manufacturing tolerances. This reduces manufacturing complexity while maintaining sealing stability

Inventive Principle:

Principle #10Preliminary action

3Manufacturing precision

If preload is applied to both bead seal and stopper sections, then dimensional variations are reduced, but the risk of inducing plastic deformation increases

Engineering Contradiction:

Improvedimensional accuracy of stopper bead portionsVSAvoidplastic deformation resistance

Core Design Contradiction:

Manufacturing precisionVSStrength

Solution Approach 1:

The invention segments the preload application in both space and function: the bead seal section receives higher preload to improve sealing, while the stopper sections receive controlled preload specifically to reduce dimensional variations. This segmented approach ensures that the stopper portions are pre-positioned without being overloaded, maintaining their elastic recovery capability and preventing plastic deformation

Inventive Principle:

Principle #1Segmentation

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 approach reduces dimensional variations in stopper bead portions, ensuring stable sealing performance and preventing plastic deformation, thereby maintaining desired sealing surface pressure across varying loads.

Implementation Method 1

a preload applying step of applying preload to a bead seal section formed of one pair of the sealing bead portions and the seal members and a stopper section formed of one pair of the stopper bead portions in a height direction thereof, thereby plastically deforming the bead seal section and the stopper section simultaneously

Methodology Applied

Scientific EffectPlastic deformation: Plasticity

Data Source

PatentUS11380909B2Method of manufacturing separator

Publication Date: 2022.07.05 NOK CORP

AI summary

A method includes a forming step of forming a first metal separator and a second metal separator each including a protruding sealing bead portion and a protruding stopper bead portion; a joining step of joining surfaces of the first metal separator and the second metal separator on sides opposite to sides on which their respective sealing bead portions protrude, and attaching seal members in an extension direction or on distal ends of the sealing bead portion; and a preload applying step of applying preload to a bead seal section formed of one pair of the sealing bead portions and the seal members and a stopper section formed of one pair of the stopper bead portions in a height direction thereof, thereby plastically deforming the bead seal section and the stopper section simultaneously.