实用化的CAD／CAPP／CAM集成系统

本文介绍了一个实用化的ＣＡＤ／ＣＡＰＰ／ＣＡＭ集成系统。该系统是由机械产品设计人员、工艺人员和数控机床ＮＣ程编人员共同努力，在商品ＣＡＤ、ＣＡＭ软件Ｐｏｒ／ＥＮＧＩＮＥＥＲ平台上开发的。系统由三个子系统组成：零件信息识别子系统、ＣＡＰＰ子系统和自动ＣＡＭ子系统。零件信息识别子系统从三维零件中提取零件信息，ＣＡＰＰ子系统分析零件信息，自动生成零件加工工序加和工步，从刀具数据库中查询刀具及切削用量，并     

FMS中CAPP与CAM集成技术的研究

介绍了一个适用于FMS的CAPP／CAM集成系统。它由创成法CAPP系统，NC自动编程系统和它们之间的接口等主要部分组成。系统采用基于特征的零件描述方法作为集成环境下统一的零件信息模型。由CAPP系统生成的工艺规程，通过接口文件自动传输给NC编程系统，经过特征识别后，从特征NC程序库中调用相应的特征数控程序，实现NC自动编程，为检验NC程序的错误，系统还具有刀具轨迹仿真功能，系统用户界面友好，经加工验证，可用于生产。     

THFCAPP/CAM系统通过部级鉴定

由天津纺织工学院与邯郸纺织机械厂合作开发的箱座类零件机辅工艺规程设计及数控程序自动编制系统THFCAPP/CAM经过一年多运行,取得了良好的技术经济效益,受到使用厂的好评。 THFCAPP/CAM系统采用创成式CAPP设计原理,在无人工干预条件下可自动生成箱座类零件各类工艺文件以及加工中心机床程序,并直接输出穿孔纸带,供车间直接使用,提高效率数十倍到数百倍。该系统由形面描述、工艺过程自动设计、NC程序自动编制和系统维护四个子系统组成,可直接输出箱座类零件多种工艺文件。     

以GT为基础的微机CAD/CAPP/CAM集成

CIM中最重要的一项基础工作就是CAD/CAPP/CAM的集成。微机由于价格低廉已在企业中普及,性能也迅速提高,已有强大的功能,软件价格也比工作站低几十倍之多,因此开发微机CAD/CAPP/CAM系统能为大量的中小企业所接受。同时,必须以GT为基础,按零件相似性分类分族,才能有效地建立该集成系统。GT-CAD子系统是关键的一环,本文推荐全参数化的TopCAD系统作为该子系统的开发平台。并在成组技术的基础上编制GT-Capp和GT-CAM子系统,通过参数文件数据库相互连接起来。GT-CAD/CAPP/CAM集成系统在磨齿夹具中已得到成功的应用。     

回转体零件CAD/CAPP/CAM集成系统的研究与开发

本文阐述了北京第一机床厂在CIMS环境下,通过对零件特征的分析,提出了一种实用的描述产品零件的方法,在此基础上实现了回转体零件的CAD/CAPP/CAM集成系统的开发。重点论述了该系统的总体框架设计和主要功能:CAD特征定义及描述;基于商品CAD软件ICEMDDN之上的特征造型;应用通用专家智能系统开发工具,建立工艺知识库模型及推理系统;经相应的后置处理实现NC程序的自动生成及以ORACLE.EDL为柱心的工程数据库管理系统。     

郑州纺织机械厂集成化回转体零件CAPP系统（ZTMP——CAPP）鉴定意见

根据纺织总会“1994年纺织机械科技项目”的要求,郑纺机按期完成了“集成化回转体零件CAPP系统(ZTMP—CAPP)”的开发研制工作。鉴定组听取了项目的研制报告、技术报告与用户报告,查阅了资料,观看了软件演示。鉴定组认为: 1.该系统达到与CAD/CAM的信息集成。在工艺信息输入方面,既有人机交互方式,也可采用CAD的接口文件格式。系统采用创成式CAPP可直接生成NC程序。其中NC机床指令转换系统颇有特色。     

STEP-NC数控程序的信息提取与校验方法研究

分析了STEP-NC数据模型及数控程序的组织结构.针对STEP-NC条件下的CAD/CAM/CNC集成,研究了从STEP-NC文件到数控加工之间所涉及的问题和关键技术,包括信息提取、现场工艺规划以及基于工步的刀具轨迹计算方法等.实现了STEP-NC信息的自动提取和刀具轨迹自动生成等主要功能模块的开发.     

集成化的计算机辅助成组冷冲压模具零件工艺设计（GT—CAD／CAPP）

本文介绍了成组冷冲压模具零件的计算机辅助工艺设计系统。它以GT为基础,采用检索与创成相结合的工作原理、通过设置于CAD/CAPP/CAM的统一数据库,直接从CAD读取信息,便可迅速地打印出包括加工顺序、工序尺寸、工序加工精度要求、机床、刀具、夹具、量具、切削用量、工时等内容完整,标准化程度高的能够指导生产的工艺文件。文中着重介绍该系统的工作原理、系统的功能、特点及其经济效益。     

一种基于特征建模的CAD系统的研制

本文介绍了一种基于特征建模的CAD系统,指出了在CAD/CAPP/CAM集成系统中,CAD系统应具有的功能。该系统以特征建模为基础,具有新颖的几何造型手段,完备的零件特征信息,功能完善的图形系统。系统既可以输出完整、规范、直接用于生产的零件图纸,又可以向CAPP系统提供所需要的全部信息,并已实现了与CAPP/CAM系统的集成。     

浅谈CAPP系统的发展与应用

CAPP是CIMS中的关键技术,是连接CAD／CAM的桥梁。CAPP的功用是借助于计算机进行数值计算,逻辑推理功能来辅助工艺人员完成零件加工工艺路线的拟定。CAPP系统将产品设计信息转换成面向对象的加工制造信息,真正实现了CAD与CAM集成,资源共享。     

箱体零件CAD／CAPP／CAM集成系统的研究与实践

在ＣＩＭＳ环境下，针对箱体零件ＣＡＤ、ＣＡＰＰ、ＣＡＭ信息集成的功能需求，在基于特征的箱体零件信息模型、工艺计划模型与服务于工艺设计的制造环境模型的支持下，开发出了特征造型，工艺设计及加工过程仿真与ＮＣ编程等子系统，从而完成了一个集成化的箱体零件ＣＡＤ／ＣＡＰＰ／ＣＡＭ系统。     

Graph-based set-up planning and tolerance decomposition for computer-aided fixture design

Set-up planning plays an important role in integrating design with process planning and fixture design. Its main task is to determine the number and sequence of set-ups, and select locating datum, machining features and operations in each setup. Computer-based set-up planning may be used to generate automatically a setup plan based on tolerance analysis for minimizing locating error, calculating machining error stack-up and improving CAD/CAPP/CAFD (Computer-aided Fixture Design) integration efficiency. Most of the current set-up planning systems were based on empirical methods (such as rule and knowledge base) and their applications background was plus/minus a dimensioning and tolerancing (GD&T) scheme. Today, more and more industries are using a true positioning Geometric Dimensioning and Tolerancing (GD&T) scheme in design and manufacturing. To support this requirement, this paper presents an analytical set-up planning approach with three techniques, (1) an extended graph to describe a Feature and Tolerance Relationship Graph (FTG) and a Datum and Machining Feature Relationship Graph (DMG), which could be transferred to an analytical computer model; (2) seven set-up planning principles to minimize machining error stack-up under a true positioning GD&T scheme; and (3) tolerance decomposition models to partition a tolerance into interoperable machining errors, which could be used for locating error analysis or for feedback to design stage for design improvement. These techniques are implemented in a computer system and it is integrated with a commercial CAD/CAM system to support an automobile manufacturing enterprise in fixture design and production planning.     

Integration and application of feature recognition and mould manufacturing planning navigating process

Plastic injection mould manufacturing is diverse and complex. Traditional mould manufacturing planning often relied on experience and techniques. Therefore, in order not to affect the operation or even cause some loss of the enterprises, geometry information of computer-aided design (CAD) should be converted into manufacturing information of computer-aided process planning (CAPP) and CAM for automatic feature recognition to shorten the lead time. This study is the secondary development in a CAD environment creating a network plastic injection mould manufacturing navigating system and CAD/CAPP for integration and application. As part design is feature-based, each processing step can be regarded as a feature. By applying the hybrid recognition technology of the graph-based approach, the rule-based approach and hint-based approach in the analysis of part feature appearances, it can automatically categorise all the manufacturing features of the part and convert them into corresponding processes. The CAPP developed in this study can convert the part manufacturing features into corresponding processes and plan the part process sequence according to the process priority constraint relations. As proved by the case studies, the use of CAPP in this study can reduce planning time by 87%. It can provide users with a reference regarding process sequence, and speed up the part planning progress. Coupled with the mould manufacturing navigating process, it can achieve automatic design and manufacturing.     

Reverse engineering of machining operation planning

Computer-aided process planning (CAPP) is becoming increasingly crucial to today's computer-integrated manufacturing (CIM) and rapid production. To automate the process planning, feature-based operation planning systems have been suggested and studied extensively. In such a system, given a machining feature, the operator requires practical machining operation data for the feature. In this research, a system of reverse engineering is proposed to extract machining features and their associated machining operation data. Furthermore, a machining know-how database containing the extracted data is created for future operation planning. Since successful NC programs contain the machining know-how of skilled workers, the system is aimed at extracting the machining know-how data from the NC programs through reverse engineering. The extraction of the machining features and feature topologies has been addressed previously. The present paper deals with the extraction of machining operation data, including operation sequence, cutting conditions, machining type and cutting mode. A prototype of the system is developed and a machining know-how database is generated. The extraction of machining features and their associated machining operations has been verified through a variety of NC programs.     

基于特征的零件建模系统的研究

本文从CAD/CAPP集成的角度出发,提出了一个基于特征的零件信息模型,开发了一个基于特征的,面向CAD/CAPP集成的零件建模系统,初步实现了回转类零件CAD/CAPP的集成。     

复杂曲面整体叶轮CAD/CAM技术研究

根据整体叶轮的结构特点和工艺要求，提出了复杂曲面整体叶轮CAD/CAM系统的结构，探讨了各模块的主要功能。对开发过程中的关键问题：直纹面叶片曲面的加工及无干涉刀位轨迹生成算法进行了讨论，并给出了相应的仿真。     

汽车覆盖件自由曲面特征识别算法研究

特征技术应用于汽车覆盖件冲压工艺CAPP系统被认为是提高汽车覆盖件制造水平,并逐步实现CIMS的关键.应用特征识别技术,从CAD系统中识别出CAPP系统所需要的信息,将为工艺设计提供丰富的信息.通过汽车覆盖件自由曲面特征识别技术研究,提出了一种新的基于规则的特征识别算法,实现了从自由曲面模型识别出两种最基本的特征,孔类和翻边类特征.以UGII软件为平台,开发了汽车覆盖件零件模型自动特征识别功能,基本上解决了基于特征的覆盖件冲压工艺CAPP系统信息输入问题.     

STEP-compliant NC research: the search for intelligent CAD/CAPP/CAM/CNC integration

Since the first generation of Numerically Controlled (NC) machine tools was developed in the 1950s, there have been many developments which make today's NC machines completely unrecognizable from their early ancestors. Further developments, however, are now being significantly limited by the current programming language (ISO6983 or RS274D) that has been supporting NC manufacture since day one. Today a new standard, informally known as STEP-NC, is being used as the basis for development of the next generation of Computer Numerically Controlled (CNC) controller. This new standard is ISO 14649 and ISO 10303 AP 238. This standard gives CAM and CNC vendors the opportunity to integrate the capabilities of CAD/CAM systems with a new breed of intelligent CNC controllers, which have bi-directional communication of information representing standardized geometric and manufacturing data. This paper presents a comprehensive review of STEP-NC developments for a range of CNC processes. These developments include some major projects collaborated at the international level as well as those carried out by different groups of researchers in countries such as Germany, Switzerland, UK, Korea, USA and New Zealand. This paper also tries to portray a futuristic view of STEP-NC applications for CAD, CAPP, CAM and CNC integration, identifies the issues and challenges for STEP-NC, and provides a vision of a STEP-NC-compliant process chain supported by a product and manufacturing model.