Research Of Technology On Sheet-metal Processing Tolerance Allotting In Body-in-white And Quality Control

Body is one of the vehicl’es four assemblies, especially the car body, play anincreasingly critical role in the development of the auto companies, mainly in: the capacityof vehicle production depends on the capacity of the car body; the upgrading of the cardepends largely on the car body; body project is currently the most active research in theautomotive industry and developed most rapidly. The manufacturing quality of car bodyplay a decisive role in developing independent brands for our auto companiesThe key to improve the body manufactuirng quality is to reduce the deviation of thebody. BIW is a thin-walled Stamping Assembly. It has its own particular properties inmaterial, structure and process. In order to reduce body manufacturing error, we need toensure the feasibility of the product in designing, to reduce the manufacturing errors in’producing, to guarantee body assemblys error is minimized, to minimize the error of thesize of the body assembly. In this paper, on the base of traditional theory about tolerancedistirbuting, I improve the method of tolerance distirbuting to promote it practical in somedegree in the field of tolerance distirbution in design by analyze the manufacturing error ofcar body; By analyze the reason of manufactuirng error, I summairze the main reason toimpact the manufactuirng error and take measures of quality control accordingly to solvethe problem so that we can reduce welding deviation and improve manufactuirng accuracy.The paper deirved from the actual project, solving the problem of tolerance allocationand quality control which was very common in manufactuirng industry.This paper mainlyresearch the tolerance allocation of car body and quality control from following respects.Firstly, understanding the current situation of quality control of car body in domesticand foreign, In chapter two, it clairfies the calibration of appearance quality, analyzes theevaluation methods of quality control of car body and choose the different way to evaluatethe quality according to practical situation.Secondly, In chapter three, according to the particularity of the body manufactuirng, Iestablish the theory of tolerance allocation which is in keeping with ’car bodys character.In chapter four, it analyzes the main reason to impact the manufacturing quality of carbody in design and manufactuirng process, taking the specific measures to solve theproblem.Finally, In chapter five, I take some reasonable means of tolerance compensation to solve the problem in manufactuirng process by using the method of tolerance distributingof examples and test results.By the research of manufactuirng error of car body, I get much better understandingof advantages and disadvantages about the method of tolerance allocation, taking practicalmethod of tolerance allocation and measures to control the manufacturing error of car body.Not only do I improve my ability of theory, but also lay down good foundation for futurejob by reading a large of documents and obtaining practical experience.