Upset welding device
Upset welding process
The resistance upset welding was chosen to be the welding method for the device. The process produces coalescence over the entire area of facing surfaces by heat caused by the resistance to the flow of the current through the area where those surfaces are in contact. The wire ends are clamped in the welding device, current is passed through the joint heating up the abutting surfaces, and force in the direction of the wire is then applied to bring the parts tightly together.
Requirements list
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Electrically conductive clamps to attach two wire ends
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Possibility to remove welded wire in looped shape from the clamping system
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Current flow only inside clamped wire (avoiding current flow inside device structure)
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Power supply system with control over current/tension and welding time
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Possibility to align the wires in the resolution of a hundredth milimiter range (0.01 mm resolution)
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Relative movement of the clamps in the axial direction of the wire
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Application of pressing force force in the axial direction of the wire
DESIGNING THE DEVICE
MODEL 1
The first model was based on the idea of setting an angle to control the pressure between the wire clamps. This pressure would be provided to the sliding clamp by gravity.
Device in operation
SEM pictures of joints welded by the linear upset welding device.
a) Diamond wire with an outer diameter of 0.2 mm b) Diamond wire with an outer diameter of 0.35 mm