Gasket Reinforcement Body Positioning for Mold Gap Control

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Solution Overview

Problem

The existing methods for manufacturing gaskets for fuel batteries face issues with gap generation between split molds during mold clamping due to variations in reinforcement body thickness, leading to burr formation and increased gasket thickness variation.

Innovation Solution

A method where the reinforcement body is formed into a tabular shape with a thickness smaller than the gasket base, buried within the base, and positioned to contact only one split mold, using injection pressure to prevent movement and employing positioning holes to maintain stability, thus deviating the mold clamping portion from the reinforcement body's plane surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a reinforcement body with rigidity is integrally formed with the gasket to improve handling properties during assembly, then the gasket becomes easier to handle, but variations in reinforcement body thickness cause gap generation between split molds during mold clamping

Engineering Contradiction:
Improvehandling propertyVSAvoidgap between split molds
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The invention transitions from a planar reinforcement body to a three-dimensional protruding structure. The reinforcement body protrudes from one surface of the gasket by a specific height, creating a vertical dimension that allows the mold clamping portion to contact only the gasket base portion rather than the reinforcement body surface. This dimensional change eliminates the sensitivity to reinforcement body thickness variations that caused gap problems in the conventional planar design.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the mold clamping portion is set on the plane surface of the reinforcement body, then the reinforcement body can be clamped, but gap and burr generation occur due to thickness variation of the reinforcement body

Engineering Contradiction:
Improveclamping stabilityVSAvoidburr generation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the mold clamping function from the reinforcement body surface and relocates it to the gasket base portion. By designing the reinforcement body to protrude, the mold clamping portion contacts only the gasket base portion at a location deviated from the reinforcement body's plane surface. This separation of clamping function from the reinforcement body eliminates the source of thickness variation problems that led to gap and burr generation.

Inventive Principle:
Principle #2Taking out (Extraction)

3Stability of the object's composition

If the reinforcement body thickness is increased to prevent movement within the mold cavity, then positioning stability improves, but gap generation between split molds increases due to thickness variation

Engineering Contradiction:
Improvepositioning stabilityVSAvoidgap between split molds
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The invention segments the functions of the reinforcement body into distinct roles: (1) providing rigidity and preventing movement within the mold cavity, and (2) allowing mold clamping at a separate location. The protruding structure enables the reinforcement body to fulfill the stability function through its rigid protrusion, while the mold clamping occurs at the gasket base portion, separating the clamping function from the reinforcement body thickness variations.

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 prevents gap generation between split molds and burr formation, maintaining consistent gasket thickness despite reinforcement body thickness variations, ensuring accurate positioning and reduced manufacturing defects.

Implementation Method 1

the reinforcement body is not moved in a thickness direction of the reinforcement body within the cavity by injecting the molding material while pressing the reinforcement body to the inner surface of the cavity (the inner surface of the one split mold) by this injection pressure

Methodology Applied
Scientific EffectInjection pressure: Pressure Increase

Data Source

PatentEP3281760B1Manufacturing method for a gasket
Publication Date: 2020.09.30 NOK CORP
  • EP3281760B1 patent drawingFigure 1A~1B
  • EP3281760B1 patent drawingFigure 2
  • EP3281760B1 patent drawingFigure 3A~3B

AI summary

The purpose of the present invention is to make it difficult for a gap to occur between die segments of a mold during mold closure even if there is variation in the thickness of a reinforcing member, thereby limiting the occurrence of burrs and increased variation in gasket thickness due to the gap. To achieve said purpose, a gasket comprises a gasket body obtained from a rubber-like elastic material and a reinforcing member obtained from a material of higher rigidity than the gasket body. The gasket body comprises a flat plate-shaped base united with a sealing part that is provided on a width direction edge of the base. The reinforcing member is formed in a flat plate shape, the thickness of which is set to be less than the thickness of the base, and is embedded in the base so that a surface is exposed on one surface of the base in the thickness direction. The reinforcing member is provided with a positioning hole for positioning the said reinforcing member on a plane with respect to the mold for molding the gasket body.