Vehicle Roof Frame Using Polyurethane Foam Joining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle roof frames made of sheet steel are inefficient in material usage, resulting in significant waste and high manufacturing costs due to the need for large cutouts and cathodic dip coating to prevent corrosion, as well as requiring additional adhesive processes for assembly and reinforcement.
Innovation Solution
The use of individual sheet metal parts connected via a polyurethane foam coating to form weld seams, allowing for a modular construction kit system with enhanced stability and reduced material waste, while minimizing the need for additional adhesives and coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If traditional sheet steel frames with large cutouts are used, then structural strength is maintained, but material waste increases significantly
Solution Approach 1:
The frame is divided into multiple separate sheet metal parts that are stamped and bent individually with minimal material waste, then connected together using polyurethane foam encapsulation. This segmentation allows each part to be optimized for strength while reducing overall material usage compared to traditional large cutout designs.
Solution Approach 2:
The invention combines sheet metal parts with polyurethane foam to create a composite structure. The foam encapsulation not only connects the metal parts but also provides structural reinforcement, allowing for reduced material thickness while maintaining frame strength.
2Object-affected harmful factors
If KTL thick layer coating is applied to prevent corrosion, then corrosion protection is improved, but manufacturing costs increase
Solution Approach 1:
The polyurethane foam encapsulation serves as a protective layer that replaces or reduces the need for thick KTL coating. The foam provides both structural and protective functions, allowing for thinner or eliminated cathodic dip coating while maintaining corrosion protection.
3Shape
If add-on parts and covers are connected using adhesive process, then visual enhancement is achieved, but device complexity increases
Solution Approach 1:
The polyurethane foam encapsulation combines multiple functions into a single element: it connects sheet metal parts, provides corrosion protection, and serves as a mounting surface for add-on parts and covers. This eliminates the need for separate adhesive processes and simplifies the overall assembly.
Solution Approach 2:
The foam encapsulation performs multiple functions simultaneously: structural connection, corrosion protection, aesthetic finishing, and mounting substrate. This multi-functionality reduces the number of separate components and processes needed, simplifying device complexity.
4Loss of substance
If individual sheet metal parts are connected by polyurethane foam coating, then material waste is reduced, but connection strength must be ensured
Solution Approach 1:
The polyurethane foam is applied in a liquid or expandable state that fills the spaces between sheet metal parts, then undergoes phase transition to a solid, rigid foam that provides strong mechanical connection. This phase change allows the foam to bond securely to metal surfaces while providing structural strength.
Solution Approach 2:
The combination of sheet metal and polyurethane foam creates a composite structure where the foam penetrates and bonds to the metal surfaces, providing mechanical interlocking and chemical adhesion. This composite connection is stronger than adhesive bonds alone while using minimal material.
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 material waste, lowers production costs, and enhances the stability and visual appeal of the frame by using polyurethane foam for weld seams and functional sections, while potentially eliminating the need for a thick cathodic dip coating, thus improving the economic viability of the frame production.
Implementation Method 1
individual sheet metal parts of a vehicle roof frame are connected to one another by means of a polyurethane foam coating, which forms the weld seams
Implementation Method 2
a foaming process with the formation of weld seams
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a vehicle roof frame comprising a longitudinal beam (18A, 18B) made of a sheet metal part on each side of a vertical longitudinal central plane of the roof, and at least one cross-beam (20, 22, 24) that is made of a sheet metal part and connects the two longitudinal beams (18A, 18B) to each other. The longitudinal beams (18A, 18B) and the at least one cross-beam (20, 22, 24) are joined to each other by joining seams made of a polyurethane foam. The invention also relates to a method for producing the frame.