What are the main components of the welding robot?
Welding robot mainly includes robot and welding equipment.
The robot is composed of the robot body and the control cabinet (hardware and software). Welding equipment, such as arc welding and spot welding, is composed of welding power supply (including its control system), wire feeder (arc welding), welding gun (clamp), etc. The intelligent robot shall also have sensor system, such as laser or camera sensor and its control device. Welding robots produced in the world are basically joint robots, most of which have 6 axes. Among them, axes 1, 2 and 3 can send the end tools to different spatial positions, while axes 4, 5 and 6 can meet the different requirements of tool posture.
The mechanical structure of the welding robot body mainly has two forms: one is a parallelogram structure and the other is a side (tilting) structure.
The upper arm of the parallelogram robot is driven by a pull rod. The pull rod and the lower arm form two sides of a parallelogram, hence the name.
The early developed parallelogram robot has a small working space (limited to the front of the robot), and it is difficult to work upside down. However, the new type of parallelogram robot (parallel robot) developed since the late 1980s has been able to expand the working space to the top, back and bottom of the robot, and there is no stiffness problem of the measuring type robot, so it has received widespread attention.
This structure is suitable for both light and heavy robots. In recent years, robots for spot welding (with a load of 100-150 kg) are mostly robots with a parallelogram structure.
The main advantage of the side mounted (tilting) structure is that the upper and lower arms have a large range of motion, so that the working space of the robot can almost reach a sphere. Therefore, the robot can work upside down on the rack to save the floor area and facilitate the flow of ground objects.
However, the 2 and 3 axes of the side mounted robot are of cantilever structure, which reduces the rigidity of the robot. It is generally suitable for robots with small loads, such as arc welding, cutting or spraying.
Each axis of the above two robots is in rotary motion, so the servo motor is used to drive through cycloidal needle wheel (RV) reducer (1-3 axes) and harmonic reducer (1-6 axes). Before the mid-1980s, DC servo motors were used for electrically driven robots. Since the late 1980s, countries have successively changed to AC servo motors. Because the AC motor has no carbon brush and good dynamic characteristics, the new robot not only has a low accident rate, but also has a large increase in maintenance free time and a fast acceleration (deceleration) speed. For some new light robots with a load of less than 16KG, the maximum movement speed of the tool center point (TCP) can reach more than 3m / s, with accurate positioning and small vibration. At the same time, the control cabinet of the robot is also changed to a 32-bit microcomputer and a new algorithm, so that it has the function of self optimizing the path, and the running track is closer to the teaching track.
Advantages of welding robot
With the development of electronic technology, computer technology, numerical control and robot technology, automatic welding robot has been used in production since the 1960s. Its technology has become increasingly mature.
The advantages of welding robot mainly include the following aspects:
1) Stabilize and improve the welding quality, and reflect the welding quality in numerical form;
2) Improve labor productivity;
3) Improve the labor intensity of workers and work in harmful environment;
4) Lower the requirements for workers' operation technology;
5) Shorten the preparation period for product transformation and replacement, and reduce the corresponding equipment investment.