How to Choose a Positioner for a Welding Robot
Positioners are generally classified according to the number of drive motors: single-axis positioners, dual-axis positioners, three-axis positioners, and composite positioners. Before and during welding operations, the positioner uses fixtures to clamp and position the workpiece to be welded. Different requirements for the workpiece determine the positioner's load capacity and movement mode. As an important component of robotic welding production lines and flexible welding processing units, the positioner's function is to rotate (translate) the workpiece to the optimal welding position.
1. Single-Axis Positioner
Single-axis positioners are generally classified into L-type and C-type according to their structural form. An L-type positioner includes: an active head, a tailstock, and a mechanical frame. The active head is generally driven by an external axis of the welding robot, enabling coordinated movement with the welding robot. The tailstock is unpowered and uses a follower system. L-type positioners are mainly used for welding rotating workpieces.
2. Dual-Axis Positioner
Dual-axis positioners, primarily type A, consist mainly of a rotary axis, a tilting axis, and a mechanical frame. They are generally driven by external axes of the welding robot to achieve coordinated movement. Theoretically, any weld seam can be positioned horizontally or in a boat-shaped welding position. Type A positioners are typically used for welding multi-faceted workpieces (weld seams distributed across multiple faces).
3. Three-Axis Positioner
Three-axis positioners are generally classified into K-type and R-type based on the form of their rotary axes.
K-type positioners include a vertical main rotary axis and two additional rotating heads (equivalent to an L-type positioner). They are generally driven by external axes of the welding robot, enabling coordinated movement with the robot. K-type positioners are mainly used for welding rotating workpieces. A key feature of K-type positioners is that the positioning motion primarily occupies vertical space, saving horizontal space.
R-type positioners include a horizontal main rotary axis and two additional rotating heads (equivalent to an L-type positioner). They are generally driven by external axes of the welding robot, enabling coordinated movement with the robot. R-type positioners are mainly used for welding rotary workpieces. The characteristic of R-type positioners is that their movement primarily occupies horizontal space, saving vertical space.
4. Composite Positioners
Composite positioners are combinations of the various types of positioners mentioned above. Here, we mainly introduce the B-type and D-type types.
A B-type positioner consists of two A-type positioners and one C-type positioner. Each A-type positioner serves one station, and the C-type positioner is used for station switching. A D-type positioner consists of two dual-axis positioners and one C-type positioner. Each dual-axis positioner serves one station, and the C-type positioner is used for station switching.
The core of selecting a positioner for a welding robot is choosing an "external axis" that can "work seamlessly" with the robot. In practical applications, it is also necessary to adjust and optimize the equipment's performance parameters according to the specific requirements of the welding task to achieve better welding results. In short, only by fully understanding and rationally utilizing the performance parameters of the welding positioner can the advantages of the equipment be fully realized, improving the efficiency and quality of welding production.
