Research On Integration Technology Of Automobile Muffler Welding Robot System

To improve the product quality of automotive exhaust system and production efficiency, and prolong the service life of the automobile, it is very important to ensure the welding quality. Automatic welding equipment is the right key to improve the welding quality of the muffler and to reduce the production costs.This paper is a study of muffler assembly welding automation system design in the automobile exhaust system, which is an important part in the welding of automobile exhaust system. This paper first introduces the characteristics of automobile muffler structure, and then introduces the research status of automobile muffler welding process and robot welding technology.According to the present situation of domestic automobile muffler production, and considering the economic and practical, a set of integrated system of muffler robot welding, composed of arc welding robot and horizontal girth welding machine, was developed. After analyzing the structure of the muffler assembly, based on the principle of modular, serialization and standardization, three fixture platforms made by six sets of fixture modules were designed. The design principle of fixture platform is that the fixture and beam clamp can be replaced as a whole. The design principle of six sets of fixture is that the beam clamp and the electromagnetic valve terminal, which are designed based on the flexible design of welding fixture, have no need to be replaced, just the fixture installed in the fixture beam is replaced quickly. The 3D design integration system of the robot welding process reflects the thought of flexible welding and assembling.The original robot control cabinet is not only to control the robot, but also to control the position, fixture and welding module etc, and to coordinate the logical relationship between the various parts to avoid interference, which leads to serious coupling. The control system is decomposed into the PLC control system and robot control system. Part function of the original robot control cabinet is isolated, and design PLC control cabinet as system controller control of fixture, sensors and other equipment. The original robot control cabinet is retained control robot, welding system and the function of teaching box. Using PROFIBUS-DP bus as communication bus site welding unit, PROFIBUS-DP communication protocol is designed to control the two control cabinet system cooperatively.Finally, the process characteristics of muffler, which is welded by the developed welding robot integrated system, is researched, and welding process represented by the muffler assembly in the catalytic converter assembly ring seam is optimized by using orthogonal design method, and taking the welding residual stress as the evaluation index. Then, by using the finite element simulation software Marc to carry out numerical simulation with the welding residual stress under the optimal welding process, and obtain the residual stress distribution of the catalytic converter assembly welding joint, which provides a reference for study of the muffler welding process optimization.