Zero Gap Butt Joint for Closed Section Structural Elements
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for forming closed section hollow structural elements from sheet metal, such as vehicular components, rely on overlapping or flange-type joints which result in redundant material and are sensitive to manufacturing process limitations, making it difficult to achieve a zero gap butt joint.
Innovation Solution
A method involving press forming of sheet metal components with parallel flanges, followed by complementary trimming using five-axis laser cutting and rigid holding in a fixture to achieve a zero gap interface, allowing for a high-quality continuous laser butt weld without redundant material, reducing material usage and heat impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional overlapping or flange-type joints are used to form closed section hollow elements, then the manufacturing process is simpler and more tolerant of process limitations, but redundant material is used and the joint quality is compromised
Solution Approach 1:
The interface flanges are complementarily trimmed using five-axes laser cutting before welding to achieve a zero gap interface. This preliminary trimming action removes material inaccuracies and creates precise mating surfaces that enable high-quality laser butt welding without redundant material overlap.
Solution Approach 2:
The patent replaces conventional mechanical joining methods (overlapping joints, flange spot welds) with laser butt welding. This substitution eliminates the need for redundant material and provides superior joint quality through a continuous weld seam with no gap or overlap.
2Loss of substance
If a zero gap butt joint is attempted using press formed components, then material redundancy is eliminated, but the manufacturing process capability is exceeded due to edge development limitations
Solution Approach 1:
A purpose-built fixture serves as an intermediary device that rigidly holds the upper and lower sheet metal components in dimensional compliance during laser trimming and welding. The fixture compensates for press forming limitations by providing external constraint and alignment, enabling zero gap interface achievement despite inherent process inaccuracies.
Solution Approach 2:
The interface flanges are complementarily trimmed using five-axes laser cutting before welding to achieve a zero gap interface. This preliminary trimming action removes material inaccuracies and creates precise mating surfaces that enable high-quality laser butt welding without redundant material overlap.
3Productivity
If laser welding is used for butt joints, then welding speed and efficiency are improved, but tighter tolerances on butt joint gaps are required
Solution Approach 1:
The interface flanges are complementarily trimmed using five-axes laser cutting before welding to achieve a zero gap interface. This preliminary trimming action removes material inaccuracies and creates precise mating surfaces that enable high-quality laser butt welding without redundant material overlap.
Solution Approach 2:
A purpose-built fixture serves as an intermediary device that rigidly holds the upper and lower sheet metal components in dimensional compliance during laser trimming and welding. The fixture compensates for press forming limitations by providing external constraint and alignment, enabling zero gap interface achievement despite inherent process inaccuracies.
4Ease of manufacture
If overlapping joints are used to accommodate press forming limitations, then manufacturing feasibility is improved, but heat input and material usage increase
Solution Approach 1:
The interface flanges are complementarily trimmed using five-axes laser cutting before welding to achieve a zero gap interface. This preliminary trimming action removes material inaccuracies and creates precise mating surfaces that enable high-quality laser butt welding without redundant material overlap.
Solution Approach 2:
The patent replaces conventional mechanical joining methods (overlapping joints, flange spot welds) with laser butt welding. This substitution eliminates the need for redundant material and provides superior joint quality through a continuous weld seam with no gap or overlap.
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 results in a lightweight, cost-effective closed section hollow structural element with high dimensional integrity and variable cross-section ratios, eliminating material redundancy and manufacturing inaccuracies, while enabling efficient laser welding with minimal heat and faster processing.
Implementation Method 1
the press interface flanges of the upper and lower sheet metal components are complementarily trimmed using five-axes laser cutting
Implementation Method 2
The trimmed edges of the upper and lower components may suitably be welded to one another by a continuous laser butt weld
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A vehicular structural member is provided from a closed section hollow element that utilizes a conventional clamshell configuration but eliminates the overlapped joint of the prior art. It has been proven that for large volume applications such as those dictated by the automotive industry, sheet metal press forming is the most cost-effective method of manufacturing structural components. The present disclosure eliminates the redundant material associated with overlapping or flange type joints in clamshell closed section hollow elements thereby reducing weight and cost.