Research On Transmission Parts’ Parametric Design Technology For Combine Harvester Chassis

Research on modeling methods for Combine Harvester Chassis is part of the12th“Five-Year” National Science and technology support program project “Digital design of agriculturemachinery chassis and lean manufacturing of complex parts"(project number:2011BAD20B-01).Combine harvester chassis parts have lots of series, and similar with each other. Thetraditional development mode is a kind of linear phase mode, which requires repeatedmodification and improvement from design to prototype trial. So the product developmentcycle is long, with high cost, and the quality is difficult to be the best. After establishing theparametric design model library for chassis key parts, designers only need to select thedesired type of chassis components from the model library, and modify several parameters,then they will get satisfied design results in a very short time. The research is of important andpractical significance in improving the design efficiency of combine harvester chassis andshortening the design cycle.This article studies the parametric design method based on CATIA, and applies it to thetransmission parts’ parametric design for combine harvester chassis, the main work is asfollows:(1) The article introduces the basic concepts and developing trend of CAD technology；summarizes recent situation of CAD technology’s application in combine harvester designing.(2) The article expounds the basic theory of parametric design and feature technology,introduces the methods of realizing parametric design, summarizes processes of parametricmodeling based on feature.(3) The knowledge Advisor of CATIA V5is applied to the parametric design of combinechassis transmission common parts (shaft, pulley, sprocket et al.). We extract templatemodels’ feature parameters of these parts, express the parameters with the formulas andgenerate a list of parameters, input the parts’ series sizes to their parameter lists, and thusparts will be changed according to the dimension driven. (4) We use the Catalog library file of CATIA to realize classification management ofcommon parts’ knowledge system and form the transmission common parts library. With thelibrary we build and CATIA’s own ISO standard parts library, combine harvester transmiss-ion’s standard and common parts can be parametric designed easily.(5)The object-oriented programming languages are used to carry on CATIA’s second-development. This paper expounds the modes of CATIA’s second-development, and analysisthe composition structure of the Automation interface object and the Automation APIfunctions used in system development. Then we summarize the approach and steps ofCATIA’s second-development by Visual Basic6.0, and analyze the structure of clutch.Finally, we build the parametric design system with visual interfaces for clutch’s key parts byCATIA’s second-development through VB6.0.