The key structural parts of construction machinery such as bulldozers, excavators and road rollers are complex and the welding is difficult. The welding quality of these key components directly affects the overall performance of the machine. Choosing the right welding positioner not only improves the welding quality and production efficiency, but also reduces the labor intensity and production cost of the workers, and is conducive to on-site management. Based on practical experience, this paper introduces the types and selection principles of Shantui's commonly used welding positioner.
1. Types of commonly used welding positioners
The basic forms of the commonly used manual welding positioner are the outrigger type, the tilting type and the double column type single rotation type.
(1) Double column single rotary type
The main feature of this type of welding positioner is that the motor-driven working device at one end of the column runs in one direction of rotation and the other end is driven with the active end. The two side columns can be designed to be lifted to meet the welding requirements of structural parts of different specifications. A disadvantage of this type of welding positioner is that it can only be rotated in one circumferential direction. For this purpose, it is necessary to pay attention to the suitability of the weld form. As shown in Figure 1, this type of welding positioner is being used to weld the Shantui excavator boom.
(2) Two-seat head and tail double-rotation
The two-seat head-to-tail double-rotation welding positioner is the movable space of the welded structural member, and a rotation degree of freedom is added to the double-column single-rotation welding positioner. This type of welding positioner is more advanced and has a large welding space, which can rotate the workpiece to the required position. It has been successfully applied in many construction machinery manufacturers. The welding positioner shown in Fig. 2 is being used to weld the X-type excavator X-frame.
(3) L-shaped double-rotation
The working position of the welding positioner is L-shaped, and has two degrees of freedom of rotation, and both directions can be arbitrarily rotated by ±360°. The advantage of this welding positioner is that it is open and easy to operate. Figure 3 shows the L-shaped double-rotation welding positioner being used to weld the rear axle box of the bulldozer.
(4) C-shaped double-rotation
The C-shaped double-slewing welding positioner is the same as the L-shaped double-slewing welding positioner, except that the fixture of the welding positioner is slightly changed according to the shape of the structural member. This type of welding positioner is suitable for welding of structural members such as loaders and buckets of excavators. Figure 4 shows the C-shaped double-slewing welding positioner being used to weld a Shantui excavator bucket.