Research On The Structure Optimizied Design Of The Checking Fixture For Automobile Front Door Based On MSC.Patran

Body covering parts quality directly related to the quality and performance of vehicle automobile body covering parts precision demand is higher and higher. As a special inspection tools, fixture possesses the characteristics of convenient, quick, accurate and suitable for mass production product inspection, but the detection accuracy of the fixture need to improve urgently. In the fixture’s design, manufacture or use process will cause the corresponding accuracy error.Reduce the impact of fixture accuracy caused by design has significant meaning to improvement of the fixture’s detection precision. Car fixture is mainly used to detecting element, positioning device, clamping device, base, auxiliary device, etc.The assembly of the automobile door has a unique position, the improvement of the fixture accuracy is the key point of research among the entire industry. In order to improve the the accuracy of automoblie door’s fixture, guarantee the accuracy of product testing, this paper takes a car’s front door as an example, has carried on several aspects of research as followed:1、The modular design study of Auto parts’ fixture, elaborated the principle and standard of design systematically in aspect of each module, summarized the basic specification in design of the fixture, listed the examples about the design of car fixture, studyed the automobile front door’s design process detailed.2、Car body fixture itself has gravity deformation, deformation of gravity has a great influence on the detection precision of fixture. This paper is intended for the gravity deformation of the car front door, and car front door fixture gravity deformation finite element model is established, Through MSC. Patran, a finite element analysis software, the car front door and fixture body’s gravity deformation are analyzed, and from optimizing backplane, increasing the number of bearing, etc to optimize fixture structure, reduce the fixture gravity deformation and relative deformation.3、The thermal deformation caused by the temperature change is a key factor which affected the accuracy of the fixture. This paper is intended for car front door thermal deformation, the theoretical foundation of thermal deformation is discussed, and the automobile front door fixture thermal deformation finite element model is established. through the software MSC. Patran, car fixture body thermal deformation analysis were carried on in 5 ℃ to 35℃ by setting expansion joint method, optimizing the fixture structure, reducing fixture thermal deformation and relative deformation.4、studied the design method which combined technique of finite element analysis and mechanical optimization. The theoretical foundation of finite element analysis and mechanical optimization is discussed. This paper proposed a structural optimization method of the car front door fixture’ gravitational deformation and thermal deformation,which based on finite element analysis technology. This methond can effectively reduce the gravitational deformation deformation relative deformation and thermal deformation relative deformation.In this paper, the finite element technology combined with mechanical optimization design method, through structure optimization methods, such as optimizing backplane, increasing support and setting expansion joint, effectively reduce the fixture gravitational deformation relative deformation and thermal deformation, improved the accuracy.