Variation Modeling And Process Optimization For Automotive Sliding Door In Moving

Body panel matching process lies on the utmost downstream of auto-body assembly operations. It fits the closure panels with BIW's eight openings. The matching quality has direct effects on airtightness and wind noise. It also affects the vehicle's appearance and market competitiveness. Because of small opening, difference of movement pattern and assembly locating, there are a lot of factors affecting the matching quality and assembly variation of sliding door to body of the car.The article analyzes and researches the movement pattern of sliding door, installation characteristics to the body, the choice of location scheme and so on, to carry out the study of variation modeling and process optimization for automotive sliding door in moving, which aims at improving the matching quality of the sliding door to the body, enhancing the smooth of the sliding door movement, and promoting the design and manufacturing level continuously.Firstly, with the requirement for matching accuracy of the sliding door to the body, to analyze the matching location by the numbers at the closed state, to choose the location scheme according to the installation pattern of sliding door, and to build assembly variation model for a type car with tolerance analysis software Vis_VSA for simulation and calculation; Secondly, with some positions for the sliding door on the rail, to analyze and build dimensional chain models for the gap between rails and rolls at C/C and U/D directions as closed–loops. It is necessary to verify the dimensional chain models described above are reasonable and correct with the comparison of calculation results between dimensional chain model and VSA assembly model; Finally, it is feasible to do multi-objective process optimization aimming at the uniformity of gap variations between each rail and roller in the process of sliding movement.The main study is as follows: (1) The matching variation modeling and optimization design between sliding door and body sideThe choice of sliding door location scheme: According to―3-2-1‖location principle and analyzing the type of connection and assembly characteristics between sliding door and body side, we could ascertain the appropriate location points and their control directions.The assembly variation modeling of closed sliding door based on Vis_VSA: To build assembly variation model of sliding door to side body with tolerance analysis modeling software VSA, then, we could carry on simulation and calculation with the specific variation data and analyze the simulation results.(2) Assembly variation modeling of sliding door in movingTo establish assembly dimensional chains of sliding door in moving: To comprehend fully about assembly relationship of concerned parts, and establish assembly dimensional chains at the beginning position, the middle position and the closing position when sliding door moves on the rails. It should be on the basis of taking the dimensional tolerances and geometric characteristic tolerances into account, including assembly between rails and body, roller brackets and sliding door. The closed-loops are gaps between rails and rolls in the C/C direction and the U/D direction when assembly process is completed.To analyze the variation trend of every gap variation between rail and roller during the whole movement of sliding doors on the rails, and analyze the factors that affect the assembly gap variations seriously. Because the variations of assembly gaps are affected by different factors when sliding door moves to different positions.To establish assembly variation model of sliding door in moving based on Vis_VSA software taking the same tolerances into account as dimensional chains modeling, and compare the simulation results with calculation results. That could verify the validity and reasonableness of the dimensional chain model of sliding door in moving.(3)Process optimization and design of homogeneity for sliding door assembly variationAssembly variation Optimization of sliding door in moving: We could get key factors through analyzing the assembly variation trends of sliding door in moving. The next step is founding optimization functions that could estimate the uniformity of gaps variation of sliding door assembly, including C/C direction and U/D direction. At last, we could obtain the multi-objective optimization results with the aid of mathematical analysis software.The main points of this article is to research the assembly variation modeling of sliding door in moving with dimensional chains and to optimize the uniformity of gaps variation , which is based on drawing fully on the experience of study about common car door. It would be linking up with the CAD model and real data to analyze and calculate in order to ensure that the research is reasonable and reliable. The method referred above not only contributes to improve continuously the design level and assembly quality of sliding door, but also have some reference to researching to improve the assembly accuracy of other similar sliding devices and rails.