Synchronized Three-dimensional Tolerance Design Research And Development And The Growth Of Conceptual Structure

The current research on tolerance design mostly concentrates on the detailed design stage. There is very little research that focuses on the application into the earlier period of the design and the 3D tolerance design. The core of this paper is the study on National Nature Science Fund Project (No:50475129), named 'Study on evolving theory and technology of synchronous synthetic tolerancing in product conceptual design'. According to the principles of 'top-down' and 'Decomposition and Reconstitution', the 3D tolerance design are studied in the conceptual- structure design stage based on Growth Design Methodology of conceptual structure. Development the synchronous system for the 3D tolerance design and structure in concept design process and proved by examples. The 3D tolerance design in conceptual- structure design stage can identify the product problem, lessen the design rework, shorten the design period and reduce the cost.The main content of this paper is organized as below:In the first chapter, the current research situation of present domestic and overseas computer aided tolerancing and conceptual design is summarized. Based on those, the key techniques and development trends are proposed. The necessary of 3D tolerance design in the early design stage is to explain and the research goal and the paper frame is put forward based on the content mentioned above.In the second chapter, on the basis of the comparability between conceptual design of product and biology growth, researched three basal theories: Theory of Decomposition and Reconstitution (D &R), Function Face and Generalized Location Principle. This paper also combined the tolerance design with the conceptual-structure growing design and put forward the theory of 'synchronous 3D tolerance design in the conceptual-structure growing processing'. Built the integration model of function-structure-tolerance and give a general frame of synchronous 3D tolerance design in the conceptual-structure growing process.The third chapter constructed the four-hierarchy tolerance representation model and analysis the constraint in the product nominal construct. This paper also introduced the screw and researched the corresponding relations of tolerance types and the screw. At last, the single step of 3D tolerance design and the overall optimization frame are put forward.In the forth chapter, the concept of the standard function location model is first presented and put forward the rules of the tolerance types automatic generation. Searches the three dimension chains automatically and takes the distribution and calculation by the kinematics model.In the fifth chapter, on the basis of the original design system DARFAD researches the system implement. Finally, the validity of the methodology is illustrated by the design of location disk in the piston clamp.At last, all of the work in this dissertation is summed up, and the future researches are prospected.