Expandable Cavity Sealing for Vehicle Frame Noise and Dust Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for sealing automotive vehicle frames are inadequate in reducing noise, improving stiffness, and preventing the entry of air, dust, and moisture, while also being cost-effective and lightweight.
Innovation Solution
A system employing an expandable material with a high expansion rate, activated by heat, is applied to the vehicle frame using an extruder, which expands to seal cavities effectively, improving sound absorption and structural integrity without requiring holes in the frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If baffle structures are employed within hollow cavities to block sound propagation and prevent entry of air, dust, and moisture, then noise reduction and sealing performance are improved, but device complexity and weight increase
Solution Approach 1:
The invention changes the physical state and volume parameters of the sealing material by using a foamable composition that expands significantly (at least 400% expansion rate) when exposed to heat. The material transitions from a compact applied state to an expanded sealed state, fundamentally changing its volume and sealing capability without requiring complex pre-formed structures
Solution Approach 2:
The sealing composition undergoes a phase transition from a liquid or semi-solid applied state to a expanded foam state through thermal activation. This phase change enables the material to fill cavities and conform to surfaces automatically, replacing complex mechanical baffle structures with a simpler thermal expansion process
2Reliability
If traditional sealing materials are applied to cavities, then sealing is provided, but the materials are not dry to the touch at ambient temperature causing handling and stacking difficulties
Solution Approach 1:
The invention employs a time-temperature sequence where the sealing material is applied in a non-tacky state, allows brief ambient drying period, then undergoes thermal expansion during vehicle frame heating processes. This periodic action sequence ensures the material is handleable when applied but becomes fully sealed when heated
Solution Approach 2:
The material's tackiness and handling properties change with temperature. At ambient temperature, the composition remains non-tacky and handleable, but when heated during vehicle production, it transitions to a sealed foam state. This parameter change with temperature resolves the contradiction between immediate handling ease and final sealing reliability
3Object-affected harmful factors
If the expandable material has a high expansion rate of at least 400%, then sealing performance and noise reduction are improved, but the application precision and control become more difficult
Solution Approach 1:
The foamable composition is applied as a relatively small amount of material that automatically expands to fill the cavity space when heated. The material self-regulates its expansion to conform to the cavity boundaries without requiring precise application measurements or complex control systems during application
Solution Approach 2:
The material is applied in a controlled, compact state before expansion, allowing for easier and more precise initial application. The preliminary application phase enables precise placement, and the subsequent thermal expansion automatically fills the remaining space and conforms to cavity boundaries
4Strength
If heat is used to activate the expandable material during vehicle production, then sealing and structural properties are improved, but energy consumption increases
Solution Approach 1:
The thermal heating process serves multiple functions simultaneously: it cures the sealing composition, activates the foam expansion, and provides structural heating benefits. By combining these functions into a single thermal process, the energy consumption is optimized rather than requiring separate heating, curing, and expansion steps
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 system provides reliable and cost-effective sealing, reduces noise, enhances structural properties, and prevents air, dust, and moisture entry, while being easy to handle and apply, with improved adhesion properties and reduced risk of adhesive failure.
Implementation Method 1
the expansion rate of the expandable material is ≥400%, preferably ≥800% or >800%, more preferably ≥1000%, when exposed to heat usually provided to the vehicle frame during automotive vehicle production
Implementation Method 2
for improving sound absorption in an automotive vehicle
Data Source
AI summary
The present invention relates to a system for scaling a cavity of an automotive vehicle frame, wherein a wall is associated with an automotive vehicle structure; and an expandable material is disposed by an extruder over at least a portion of said wall and in contact with said wall prior to expansion of said expandable material, wherein the expansion rate of the expandable material is at least 400% when exposed to heat usually provided to the vehicle frame during automotive vehicle production and wherein the expandable material is prior and after its disposition to said wall dry to the touch at ambient temperature.