摘要 |
A fast response weld head (2) and a control system (60) allows user control of critical welding parameters such as speed, force, position, and duration. In one embodiment, the control system (60) includes a position servo loop (64, 66, 16, 50, 70) attached to a motor driven output shaft (36) on which a welding electrode (38) is mounted utilizing a follow-up spring assembly (44). During a weld cycle, the control system (60) moves the welding electrode (38) toward a workpiece (46) at a rapid user-defined rate. Just prior to contact this rate is reduced to prevent damage to the parts. When contact is made, the force exerted by the electrode (38) on the workpiece (46) is measured until the measured force equals a user-defined optimum welding forc e. When the weld is complete, the welding electrode (38) is automatically raised by the control system (60) releasing all pressure on th e workpiece (46).
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