| The good tolerancing can improve the assemble performance. It is important to establish thetolerance design methods for the landing gear design. In the paper, the mechanism for the landing gearof the aircraft is taken as the model, and the tolerance design methods which combine the traditionaltolerance design methods with the computer-aided tolerancing technology are researched.The main contents of the paper are as follows. In this paper, the importance of the tolerancedesign in the aircraft design process and the relationship between the tolerance design and the aircraftsafety are analyzed. The significance of the mechanism for the landing gear is described, and theactuality of the internal and overseas researches on tolerancing is discussed, the tolerance designmethodology for the mechanism of the landing gear is presented. In this paper, the theory of thedimension chain is introduced, the theoretical analysis model which are based on the statisticalanalysis method and worst-case method and the Spotts method is established. The theoreticaltolerance analysis results of the mechanism are proposed. the tolerance simulation methods areintroduced, the tolerance simulation model is established, the3DCS software to simulate the tolerancedesign is used, then modifies the tolerance design. In this paper, the theoretical tolerance sensitivityand contribution models are established, the sensitivity and the contribution of the mechanism areanalyzed, in this paper, the statistical tolerance sensitivity and contribution model for simulation areestablished, then the tolerance sensitivity and the contribution are simulated. In this paper, thetolerance allocation and optimization model which is based on the assembly ability are established,then the tolerance design is optimized, the tolerance allocation and optimization model which is basedon the manufacturing cost are established, then the tolerance design is optimized, the toleranceallocation and optimization model which is based on both and manufacturing cost are established,then the tolerance design is optimized.The conclusions for the research works of the paper are as follows. Generally, the tolerancedesign results which are based on the traditional tolerance design methods are not the optimum results.The traditional tolerance design methods are combined with the computer-aided tolerancingtechnology to modify the tolerance design methods. The sensitivity results which are based on thetheoretical cannot represent the affect for each part of the mechanism precisely and particularly, thecomputer-aided tolerancing can do it; the tolerance contribution simulation results for each part of the mechanism are similar to the theoretical results, and it can provide the suggestion for the engineering.The optimizing methods which are based on the assembly ability and manufacturing cost can improvethe tolerance design, then ensure the assembly ability and manufacturing cost.The research works of the paper provide a feasible tolerance design project for the engineering,and provide some suggestions for the future tolerance design. |
