차량용 엔진 프레임 고정을 위한 Stud-bolt 자동 교정 장치 개발에 관한 연구

Abstract

The current trend of automobile industry is towards lightweight, low-cost and simplified assembly process. In order to, therefore reduce manufacturing cost and to enhance quality, it is significant to improve the welding-assembly which claims substantial process of automobile assembly process. Especially, the automation of automotive parts stud welding is far behind. There is a growing need for advanced technology of electric and electronic as well as other types of convergence technologies, and major foreign automobile manufacturers conduct trilateral research and development project for customized automotive technology through cooperation with specialized welding robot manufacturer and other robot makers. The automated stud-welding technology is aimed to strength market competitiveness of automobile manufacturer by reducing manufacturing expenses of manual welding incurred from repair-ment, total quantity rebound gammer test and visual inspection. Also, stud-welding automation is supposed to help car-makers to overcome a low productivity and non-preference of welders on manual manufactures share their automated stud-welding technology with specialized automation service providers and welding equipment manufacturers for developing an optimized welding technology, and furthermore such welding technology is applied to their assembly lines on the basis of manufacturing cost cutting, customer confidence earning and product quality improvement. Since a stud bolt is manually positioned and adjusted in automobile body assembly process, it requires numbers of assembly-workers. Normally, daily output per assembly-worker is only 500 but, currently almost 1,000 car bodies are processed by each worker that may cause a physical injury. Moreover, the simple and repetitive physical works produce a muscular-skeletal disease, and the automobile manufacturers are suffered from a high turnover rate of assembly-workers due to such poor working conditions. Frequent replacement of skilled worker increases a defective ratio of car body assembly. Therefore, the stud-welding is greatly required to be automated in connection with improvement of both working environment and product quality. For instance, a defective ratio of stud bolt is reaching 2% with visual positioning and adjustment by ordinary worker. Subsequently, extra 30 minutes delay is inevitable for further re-adjustment.

Thus, the objective of this paper is to develop an automated stud bolt positioning & adjustment apparatus for fixing engine frame, and its control program as sell as monitoring system.