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

With the increase of appeal about the quality of Body-in-white,the precision of Body-in-white is focused on more and more by automobile engineering department.It is universally acknowledged that the quality of Body-in-white affects the quality of the vehicle at first hand,and the quality of Body-in-white lies on the quality of sheet-metal.Many parameters may be defined the quality of Body-in-white,and one of those is the precision of dimension.The precision of sheet-metal affects the precision of Body-in-white by the framework of Body-in-white.If we want to assure the precision of Body-in-white,we must assure the precision of sheet-metal at first.Engineers allot tolerance for sheet-metal firstly,and then they estimate the range of error according to the framework of Body-in-white.If we can not allot rational tolerance for sheet-metal firstly, the biggish range of error may result in the unqualified Body-in-white,and which also requries that we must modify die.At the same time,chich will bring tremendous loss at every aspect.So the work of alloting toleranc for sheet-metal is very important in Body-in-white engineering.Because the particularity(material, framework, craftwork) of Body-in-white, the conventional theory of alloting tolerance for Body-in-white looks imperfect,which can not incarnate the particularity of Body-in-white. In this dissertation,I research the condition of the precision of Body-in-white, and ameliorate the technology of alloting tolerance based on the conventional theory. I think it will push the engineering application at the aspect of alloting tolerance.According to demand of appearance and function,engineers ascertain the tolerance of Body-in-white which is our target.1. According to capacity of pressing,we allot tolerance for sheet-metal firstly.2. According to the particularity of Body-in-white and the rule of error transfer,we estimate the range of error.3. Through comparing the tolerance and the range of error,if the result is eligible,we finish the work.4. Through comparing the tolerance and the range of error,we confirm whether we have alloted toleranc for sheet-metal successfully,or we will modify related parameters untill we allote toleranc for sheet-metal successfully.5. In the upper process,if we can not arrive the object,we will suggest engineers a rework about the framework untill we can allote toleranc for sheet-metal successfully.Tompiling the dissertation attachs most importance to how the tolerance is alloted.In the first place, I research the condition of the precision of Body-in-white,and we must nail down main content and purpose about the dissertation. In the next place,I analyse the realtion of the quality,craftwork and tolerance,and I research and summarize main factors which result in warp of Body-in-white.Again,we will introduce theory, means and technology project. At last,through application and coparing,we get the excellence about the amelioration technology of alloting toleranceSum:we sum up the dissertation and elicit the aspect of innovation.According to the consequence of test,we come to the conclusion that the principle of the amelioration technology of alloting tolerance is correct and it can be applied expediently and by rule and line. The aspect of innovation: When we apply the principle of the amelioration technology of alloting tolerance,we can reduce the ilrationality of pure extremum and probability and enormous work of calculating.At last ,on the base of considering the rigid body and the particularity of biw,we can make sure simple work of alloting tolerance and scientific data.