摘要
随着制造业信息化的普及,越来越多的三牙轮钻头生产企业使用计算机辅助工艺设计系统(CAPP)来提高生产效益。但是目前使用的三牙轮钻头CAPP系统是基于二维CAD平台的,随着钻头设计水平的提高和CAD平台向三维转变,已不能满足生产需要。本文正是基于这种背景,通过对特征建模技术和工艺数据库的研究,开发了基于三维CAD/CAM平台Pro/E的三牙轮钻头CAPP系统。本文的主要内容如下:
1.对CAPP与CAD/CAM集成的方式做了研究。指出采用直接集成的方式是实现CAPP与CAD集成的最根本的方法。提出采用分离模式表达CAPP系统所需要的几何信息与非几何信息,其中几何信息由现有CAD平台完成,非几何信息则由数据库管理系统完成。
2.提出了一种新的特征建模的方法“工序化建模”,实现了三牙轮钻头CAPP系统与现有三维CAD/CAM平台Pro/E的集成,为系统的开发奠定了理论基础。详细介绍了“工序化建模”的定义及特点,并以具体例子讲解了“工序化建模”的实现步骤和技术要求。
3.对三牙轮钻头CAPP系统的工艺数据进行了分析,选择SQL Server200作为数据库管理系统,并建立起了CAPP系统所需的工艺数据库。
4.以Pro/E为平台,通过二次开发方式开发了三牙轮钻头CAPP系统,该系统主要包括以下功能:零件信息录入,工艺过程三维显示,工艺文件输出等。
采用工序化建模的方式实现CAPP系统与三维CAD/CAM平台的集成是本本文的创新点。较之其它集成方法的优点主要包括:理论简单,易于掌握;起点高,直接与三维CAD平台集成;开发自由度大,针对性强。通过三牙轮钻头CAPP系统的开发再次印证了“工序化建模”的可行性,优越性。
关键词:CAPP;特征建模;工序化建模;三牙轮钻头
Abstract
Computer Aided Process Planing system (CAPP) was used by more and more thr-cone bit manufactures to improve production effectivenes along with the popularization of manufacturing informatization. But the tri-cone bit CAPP system recently used is based on the two-dimensional CAD platform. It can not meet the production demand with the improvement of design level and the transformation of CAD into three dimensions.Under the circumstances, tri-cone bit CAPP system based on CAD/CAM platorm--Pro/E is developed through study on feature modeling technical and process database. The main contents of this thesis covers the following:
1.Studying on integration mode between the CAPP and CAD/CAM. It analyzed that the fundamental way to accomplish the integration between CAPP and CAD is to adopt means of direct integration, together with geometry information and non-geometry information needed by adopting separation mode to convey CAPP system. The geometry information is accomplished by the recent CAD platform while non-geometry is achieved by database management system.
2.A new feature modeling--“modeling by Process” was proposed to accomplish the integration between the tri-cone bit CAPP system and the recent three-dimensional CAD/CAM platform--Pro/E, which placed the theoretial basis for systematic development. The definition and feature of “Modeling by Process” is fully introduced, with specific examples to illustrate its realization steps and technical requirements.
3.Analyzing the process data of CAPP system. SQL Server2000 has been chosen as the data base management system and process database that tri-cone bit CAPP system needs has been established.
4.Based on Pro/E, tri-cone bit CAPP system was developed by way of secondary development. The system mainly includes the functions as following: input of parts information, three-dimensional demonstration of process and output of process files,etc.
Adopting ”modeling by process” to accomplish the integration of CAPP system and three-dimensional CAD/CAM platform is the innovative pont of the thesis. Compared with other integration models, the merits of “modeling by process” mainly inclueds simple theory easy to be mastered, high starting point integrated directly with three-dimensional CAD platform, large development space and strong pertinence. The development of tri-cone bit CAPP system proved the feasibility and advantage of “modeling by process” again.
Key words: CAPP; feature modeling; modeling by process; tri-cone bit
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