Monday, May 16, 2016

Automatic welding technology and process control of pipeline

Pipeline all position automatic welding refers to the relatively fixed in the pipe, welding pipe car drive the welding torch along the orbit around the tube wall motion, so as to realize the automatic welding. Generally speaking, the whole position automatic welding device is composed of welding pipe trolley, running track, automatic control system and so on. The purpose of developing a fully automatic welding equipment is to improve the welding quality and productivity, to reduce the labor intensity of workers.

Welding pipe trolley
Welding pipe car is to realize automatic welding process of the driving mechanism, which is installed in the welding track, with a torch along the pipe wall of the circular motion, it is one of an important link of the pipe automatic welding. Welding pipe trolley should have the characteristics of beautiful appearance, small size, light weight, convenient operation and so on. The core part of it is walking wire mechanism and welding torch swing mechanism, regulating mechanism of feeding. Walking mechanism is composed of a motor and a gear transmission mechanism and the walking motor execution of the computer control unit sends the position and velocity command, the motor should be with speed feedback mechanism, in order to ensure the motor in pipeline girth seam of each location accurate positioning, but also has better speed tracking function. The wire feeding mechanism must ensure that the wire feeding speed is stable and accurate, with a small moment of inertia, a better dynamic performance, and at the same time, should have sufficient driving torque. And welding torch swing adjusting mechanism should have the torch relative weld left and right swing, left and right end of the stay, up, down, left and right attitude controllable torch angle can be adjusted. Welding pipe of the various parts of the car, the computer can be programmed to achieve automatic control, after the program started, the welding pipeline car parts in accordance with the procedures of the logical sequence of coordination. In the process of welding, the welding parameters can be automatically adjusted according to the amount of the intervention, and the welding parameters can be adjusted according to the amount of the intervention.
Welding track
Rail is clamped in pipe for welding pipeline trolley walking and positioning of a special mechanism, its structure directly affects the welding pipe car walking stability and positional accuracy, also affects the welding quality. The rail shall satisfy the following conditions: convenient installation and disassembly, easy positioning, reasonable structure, light weight, strength and hardness, wear resistance and corrosion resistance. Orbit is divided into two kinds of flexible track and rigid track. The so-called rigid track is that the body of the track is larger, not easy to deformation, and the flexible track is relatively rigid track. Two types of tracks each have their own characteristics. Rigid track positioning accurate and clamping deformation small, can ensure welding pipe car running smoothly, welding torch radial adjustment is small, but the weight of large, demolition is not convenient. The flexible rail is easy to install and remove, the weight is light, and the precision is not high.
Wire feeding mode

The smooth degree of wire feed directly affects the welding quality. Wire feeding method can be divided into two types of wire drawing and wire drawing. Wire drawing welding gun from send silk machine installation location is near, welding wire fittings left to send silk machine after being subjected to the smaller resistance. Therefore, it can guarantee wire feeding process is stable, but sent wire machine and wire set shall be installed in the pipeline welding car above and increases welding pipe car weight, to manual assembly disassembly increases the difficulty, increase the weight but also easy to cause pipeline welding trolley is not smooth. Diameter of 0.8 mm or 1.0 mm small wire (weighing about 5 kg) reduced the welding pipe car weight and load, and the welding process is easy to control, but the welding efficiency has certain influence.
Source: Zhejiang Yaang Pipe Industry Co., Limited (www.yaang.com)