| 摘要 |
<p>A laser welding head carried by a robotic arm welds sheet metal workpieces to each other along an elongate seam while maintaining a precise focusing of the laser beam on the seam as it is formed in the face of minor variations in the dimensions, shape and positioning of successive workpieces. The head includes a workpiece gripping assembly including a fluid pressure actuated motor having its cylinder coupled to one of two workpiece engaging members and its piston rod coupled to the other to shift the members between an open workpiece release position and a closed workpiece clamping position in which the assembly clamps the two workpiece fixedly against each other with a clamping force determined by the pressure applied to the motor. The gripping assembly is movable mounted upon a base member fixed to the robotic arm. When the workpieces are clamped by the assembly, at least one of the workpieces is engaged by a roller carried on one of the workpiece engaging members, and a laser beam focusing unit carried by that workpiece engaging member focuses the beam precisely on the surface of the roller engaged workpiece. The robotic arm moves the workpiece engaging member along the seam by rolling the roller along the workpiece surface. The workpiece gripping assembly is movable as a unit relative to the base member to "float" along the seam as may be required by deviations of the roller engaged workpiece surface from its intended position.</p> |
