Page 26 - MetalForming February 2014

Fixturing for Automated Welding in Automotive–
In the fast-paced mass- production environment of the automotive industry, development of fixtures for automated welding depends upon repeatability, proper welding-gun access and dependable spatter protection.
BY TODD WHITWORTH
Repeatability, Access and Protection are Key
Automated arc-welding cells, especially in the automotive industry, must operate correctly every time, all the time. Components for instrument panels, seats, engine cradles and other welded assemblies arrive and exit in a hurry, hour after hour, day after day.
Just as important as the welding equipment itself: the apparatus used
to fixture the component parts com- prising the welded assembly. If the fix- tures can’t readily accept, place, hold and discharge parts, welding opera- tions will fail. In addition, weld tools must hold up to the rigors of mass pro- duction, requiring dependable opera- tion part after part, while managing heat and weld spatter.
Proper fixturing also should assist, not hinder, fabrication of parts while protecting the sensors, air lines and elec- tronics on which automated production depends. If that isn’t enough, new work- piece materials and smaller part runs require increasingly robust fixturing that can be rapidly changed out.
Part Placement and Orientation
An automated welding system requires much more than just its pur- chase, installation and the expectation that parts can be tossed in and welded. A robot returns to the same position every time as part of a highly accurate process. Accuracy and repeatability of the robot requires accurate and repeat- able part placement.
Rough locators in the fixture will orient each part in close proximity to its final clamped location. In a well- designed fixture, these rough locators
Todd Whitworth is an applications engi- neer with The Lincoln Electric Compa- ny, Cleveland, OH: 216/481-8100; www.lincolnelectric.com.
Robotic welding in the automotive industry demands reliability, consistency and quality. Proper fixturing, including designs that enable proper access for the welding robot as well as rapid placement and orientation of parts, are required for meeting such demands.
24 MetalForming/February 2014
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