The Development Research And Application Of Standardized Engine Major Parts CAD System

Aiming at the problem of Low degree of integration,lack of standardizationmanagement,slow development speed,poor scalability,low code reuse rate and so on,the thesisstudy the standardized modeling process for the major parts structures of the engine,includingtop-down,parts structuralization,structure characterization,feature parameterization andparameter correlation that based on the skeleton line,and using the modeling process createfeature model library of the parts;Meanwhile, establish the child features thing characteristicstables and parameter hint pictures which are independent with any commercial CAD.On thebasis of the standardized modeling,by means of the combination of the life cycle method andobject-oriented software development methods in software engineering,according to thegeneral development process for CAD software and then package the standardized designfeature model library,child feature thing characteristics table and parameter hint pictures intothe backend database of CAD system,combine with Pro/TOOLKIT of engineering softwarePro/E and realize the man-machine interactive parametric design,at last develop a set ofengine block,cylinder head,crankshaft,connecting rod,gear and camshaft key parts CADdesign system.In accordance with the traditional design idea of the engine parts,the thesis study thespecific contents of engine block,cylinder head,connecting rod,gear and camshaft duringconceptual design,project design and detailed design phase,discuss the above componentsstructure's characterization decomposition method,on this basis create all the child parts'three-dimensional templates model including engine block,cylinder head,connecting rod,gearand camshaft,and then form complete parts subject model through Boolean;generate thingcharacteristics tables formed by independent parameters of each child characteristics andparameter hint pictures for users to modify operating etc.The thesis research and analyze the basic theory of life cycle method andobject-oriented method in software engineering,demonstrate the feasibility for application ofengine CAD system development; Based on the object-oriented method using Visual c + +.netas development environment of engine major parts CAD system and MFC (Microsoft base class) develop the man-machine interface according to consistency requirements; Through alot of exploration prove the optimal data flow solution that can achieve the abovestandardized design of the major parts for the engine,and embed it in its software system,ensure the accuracy of the data flow transmission and the consistency of the data.This software system the thesis developed is applied in engineering practice,according toreflected problems,upgrade and improve the function of software system itself and the user'soperation mode.Based on the man-machine interface design principle in the lifecycle methodperfect the consistency for operation of characteristic parameters and data show on thesoftware interface;Increasing the fault-tolerant function of the interface,can effectively avoidthe occurrence of the incorrect operation,reduce the error rate of operating software forengineering design personnel;Considering the coherence of feature selection in project designprocess,set the default selection for the user;Through the detection and maintenance of thesoftware system, improve the reliability and stability.Final application show that the developed system can finish engine block,cylinder head,crankshaft,connecting rod,gear and camshaft design,high system integration degree,standardmanagement,fast development speed,good scalability,high code reuse rate,stable and reliableoperation,and basicly meet the expected design goal.