Application of the Double-Seat Welding Positioner

The full hydraulic bulldozer is driven by static pressure, which has the advantages in comfortable operation, light weight and safety. It has a large market demand and is more and more popular with customers. The frame is the skeleton of the bulldozer, and its welding quality affects the performance of the whole machine directly. The structure of the full hydraulic bulldozer frame is quite different from that of the conventional bulldozer frame. It is hard to meet the welding quality requirements by flip welding positioner.

According to the analysis and research, we have designed a new type of dual-rotation welding positioner. It is a lifting type with double base. The welding seam will be placed in the best position if turn over the frame by this welding positioner. The welding rate of the seam on the frame can reach more than 90%. It makes welding more convenient, improves welding efficiency and welding quality. The new welding positioner can be used together with a hydraulic lifting platform. The operator can raise and lower the platform while standing on it, which ensuring the safety of the operator and reducing the labor intensity. The double-rotation welding positioner is mainly composed of a mechanical transmission system, a hydraulic system, a transmission system and a safety system.

Here we'd like to discuss about the transmission system and transmission system.

Transmission system

The drive system of the double-rotary welding positioner is divided into two parts: a rotary drive system and a flip drive system.

1 Rotary system

The rotary drive system is used to drive the frame to rotate, so that the frame welding seam can be in the best welding position. The rotary drive system is mainly composed of an AC variable frequency brake motor, a reducer, a rotary bearing, a rotary working table, a drive device, etc. The motor transmits power to the pinion gear through gear box. The pinion gear meshes with the ring gear of the rotary ring to drive the rotating table. In order to ensure the safety of the welding positioner, the drive device adopts a double self-locking structure.

2 Flip system

The reversing transmission system is composed of an AC brake motor, a reducer, a rotary bearing, and a drive pinion. The motor has function of braking. And the gear box is a worm gear structure. They form a double insurance for braking. The turning and lifting movements are driven by AC frequency conversion brake motor. The reversing action is controlled by PLC signals. The rack can be turned over when there's a certain height from the ground so that rack will not collide with the ground during the turning process. It's used to ensure the safety of equipment and operator. The lifting of the reversing mechanism is realized by the rotating screw. This screw rotates through worm gear reducer. The control panel of the flip system is provided with buttons such as reversing, braking, emergency and so on. The reversing mechanism rotates smoothly and can be safely braked at various positions, without leading or lagging on the frame reversal.

Control System

The control system of the double-turn welding positioner is mainly composed of a main control cabinet and a hand control box. The hand control box is equipped with power start and stop buttons, rotation direction, tilt direction selection switches, rotation speed adjustment and emergency stop buttons. At the same time, it is equipped with a 10m wire to connect to the control cabinet. Welding positioner can be controlled at different positions. Control system has the following functions: flipping forward, flipping backward and stop, the rotating CW, rotating CCW and stop. Motor overcurrent, overvoltage and overtorque protection are provided. The control system is reliable and easy to operate. We can control it no matter in long distance or short distance. It will be convenient for the operator to control at any station.

Summary

The ordinary welding positioner has one rotating mechanism. The new welding positioner has two rotating mechanisms, which makes more than 90% of the frame seam can be welded. Welding efficiency is greatly improved.