One-Sided Friction Stir Welding Bobbin Tool for Aircraft Joints
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Solution Overview
Problem
Existing movable joining devices for aircraft structural components require complex coordination of internal and external components for riveting, and lack the ability to efficiently weld structural components on one side, especially when dealing with curved surfaces.
Innovation Solution
A movable welding unit equipped with a bobbin tool for friction stir welding, mounted on a rail-like guiding device that allows for one-sided welding of structural components, using a rotating tool to generate friction and create a welded seam without the need for a counter bracket, and can be adjusted vertically and horizontally to accommodate curved surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a two-part riveting device with internal and external components is used, then riveting of structural components can be achieved, but device complexity and control coordination requirements increase
Solution Approach 1:
The invention extracts the counter bracket from the system by using a bobbin tool that performs friction stir welding from a single side only. The tool itself generates the necessary friction and mixing action without requiring a counter bracket on the opposite side, thereby eliminating the complex two-part device structure and reducing control coordination requirements.
Solution Approach 2:
The bobbin tool acts as an intermediary that performs both the welding and the material mixing functions. By rotating the bobbin tool against the joint line, it generates friction heat and mechanically mixes the materials from a single side, eliminating the need for coordinated internal and external device parts.
2Reliability
If traditional riveting methods are used, then structural components can be connected, but the process requires coordination of multiple device parts inside and outside the fuselage section
Solution Approach 1:
The invention removes the need for internal device parts by performing friction stir welding from the external side only. The bobbin tool extracts the complex coordination requirement by generating all necessary welding action from a single side, making the operation simpler and more accessible.
3Ease of operation
If friction stir welding with a bobbin tool is used, then one-sided welding is enabled, but the tool must generate sufficient friction heat and mixing action from a single side
Solution Approach 1:
The bobbin tool employs a curved, cylindrical geometry that rotates along the joint line. This spherical/curved surface design maximizes the contact area and friction generation capability from a single side, enabling sufficient heat generation and material mixing without requiring additional device parts.
Solution Approach 2:
The bobbin tool utilizes continuous rotation to generate periodic friction heat along the joint line. This periodic mechanical action ensures consistent heat generation and material mixing as the tool progresses along the weld, enabling effective one-sided welding.
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
Enables reliable, efficient, and precise welding of structural components on one side, reducing the complexity of internal and external component coordination, and allowing for easy assembly and disassembly, while maintaining alignment and absorbing process-induced forces.
Implementation Method 1
The friction between the at least one tool shoulder and joining edges of the structural components causes the material to under the shoulder to heat up to just under the melting point
Implementation Method 2
The pressure gradient between the front and rear side of the tool caused by the feed motion and its rotational movement transport the plasticized material around the tool, which there mixes together and forms the welded seam
Data Source
AI summary
A movable joining device for connecting structural components of an aircraft, with joining means moveably arranged on a guiding device situated on the outside of the structural components so as to fixedly connect joining edges of the structural components positioned adjacent to each other, wherein the joining means includes a welding unit that can move on the rail-like guiding device, and is equipped with a special so-called bobbin tool as a tool for friction stir welding.