Expandable Sealant for Automobile Hem Flange Joints
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Solution Overview
Problem
The existing methods for producing joints in automobile manufacture, particularly hem flanges, are time-consuming, result in variable quality, and can lead to corrosion due to trapped contaminants and inadequate adherence of electrodeposition coatings, often requiring multiple materials and processes that complicate rust prevention.
Innovation Solution
A heat-activatable and expandable sealant material is applied to one surface using a robotic process, inserted into a C or U shape on the adjacent surface, and activated to expand and bond the surfaces together, eliminating the need for pre-gelling, additional surface finishes, and protective waxes, while providing a uniform and corrosion-resistant joint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional multi-material methods are used to produce hem flanges, then rust prevention can be achieved, but the process becomes time-consuming and produces variable quality
Solution Approach 1:
The patent combines multiple functions (sealing, adhesive bonding, corrosion protection, and surface finish) into a single multi-functional sealant material, eliminating the need for separate adhesive, paintable covering layer, and protective wax layers, thereby reducing production steps and time while maintaining rust prevention
Solution Approach 2:
The sealant material is designed to perform multiple functions simultaneously: providing seal, adhesive bond, corrosion protection, and aesthetic surface finish, allowing a single material to replace traditional multi-material systems and improve production efficiency
2Reliability
If traditional multi-material methods are used to produce hem flanges, then rust prevention can be achieved, but the device complexity increases
Solution Approach 1:
The patent merges multiple separate materials (adhesive, paintable covering layer, protective wax) into a single integrated sealant material that performs all necessary functions, thereby simplifying the overall manufacturing process and reducing the number of application steps required
3Manufacturing precision
If heat-activatable sealant material is used, then uniform and aesthetically pleasing joint formation is achieved, but additional heating requirements increase energy consumption
Solution Approach 1:
The sealant material is designed to activate at specific temperature parameters (heat-activatable), allowing uniform joint formation and aesthetic appearance through controlled thermal processing, while the energy consumption is managed by optimizing the activation temperature and timing
4Productivity
If sealant material is applied using robotic process, then productivity increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent replaces manual application methods with a robotic dispensing system, which provides consistent, precise, and controlled application of the sealant material, thereby maintaining high manufacturing precision while significantly improving production speed and efficiency
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 method enables rapid, uniform, and aesthetically pleasing joint formation with enhanced rust prevention, reducing maintenance issues and ensuring consistent quality by eliminating trapped contaminants and excess material, thus improving the durability of vehicle components.
Implementation Method 1
The sealant material may be heat activatable so that its adhesive properties are developed at temperatures employed during manufacture
Implementation Method 2
The sealant material is provided at a temperature below that at which it expands and the edge of the material carrying the sealant is inserted into a C or U shape formed at the end of the second metal piece
Data Source
AI summary
Means for joining two surfaces comprise providing a heat activated sealant (7) at the end of one of the surfaces and inserting the end into a C or U shaped cup in the end of the other surface and heating to cause the sealant (7) to flow and join the surfaces. Preferably the sealant (7) is foamable, the invention is particularly useful in the production of automobile hem flanges.