Improvement Study Of Body-in-White Assembly Line Based On IE

As improvement of society and progress of science, China’s economic has developed gradually. At present, our country has established a relatively complete system of auto industry and has become the world’s first automobile-manufacturing country and consuming country. Meanwhile, as China’s rapid growth in car ownership, competition in the automotive market has been incandesced. In order to gain more market share, automobile manufacturers lay emphasis on bringing forth the new through the old, which leads to a shorter cycle life. To reach production standard as soon as possible, manufacturers make unceasing optimization on process from trial-production to regular production. Among them, how to strengthen the development stage of optimizing the automobile production line, shorten from development stage to the final formal operation period of time, is a very worth studying topic.The thesis takes Type G25 underbody assembly welding-UB production line-of an automobile manufacturer as mainly investigated subject. First of all,Stopwatch timing is used to ensure standard time of 12 stations in integrated line to find out bottleneck station. Then it researches how to improve the manual MAG welding station by basic IE theory and theory relating production line balance, optimizing manual operations by time research and method research. Orthogonal experimental design is utilized to optimize MAG welding parameter. Thus, quality of welding and efficiency could be advanced. Besides, inapposite layout is going to be improved to perfect efficiency. The thesis analyses the content and time of task of two robots with gripper in auto-gluing station of UB line and offers better solution. As the factors such like manufacture quality, cost and efficiency are guaranteed, applying analytic hierarchy process to evaluate improved solution then selecting best one. Through simulation software Robcad, path of robot will be reedited and simulated to prove accessibility of gluing and existence of interference, and then simulation time and the robot off-line programming will be offered to carry out the optimized solution successfully. Task time of the two robots will be balanced by this improvement, and then balance rate and efficiency will be also promoted. Evaluation about balance rate and efficiency will be made after this improvement.Each actual cycle time after the improvement was shorter than expected cycle time, which means fulfilling manufacture requirements. After the improvement, the longest task time has sunk from 107.5s to 91.5s, balance rate has risen from 84.74% to 95.42% and the equilibrium index from 18.04 to 4.97. The evaluation result of UB production line in improved PT phase was excellent, and it laid a good foundation for successfully developing PP phase and subsequent SOP phase.