汽车覆盖件冲压工艺CAPP系统特征建模技术

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.为此,本文对汽车覆盖件进行了特征分类,建立了面向CAPP系统的覆盖件特征表达模式.以UGII软件为开发平台,提出自动识别孔类特征算法,采用交互式特征识别方式识别其他特征,建立了覆盖件特征模型,解决基于特征的覆盖件冲压工艺CAPP系统信息输入问题.     

冲压件的特征识别技术研究

特征识别是指从产品中识别出具有一定工程意义的几何形状,即特征信息的过程.作为CAD与CAPP间的智能接口,特征识别技术对实现CAD/CAPP/CAM的集成具有重要意义.针对冲压零件,尤其是带体积成形的冲压件的特点,提出了一种新型的冲压特征识别算法,并对特征识别中的难点-特征相交问题提出基于痕迹的冲压件相交特征识别方法.     

基于KBE的汽车覆盖件冲压工艺方案设计

汽车覆盖件的冲压工艺方案设计是一个复杂且经验性强的创造性过程,需要一种支持多种知识表达模式和多智能决策技术的方法,解决工艺方案决策问题.通过以工艺特征为核心来表达知识,建立了基于KBE的覆盖件工艺知识模型,采用基于知识驱动决策树表达模式的特征转换机制来实现设计特征到工艺特征的映射,在工艺知识库的支持下完成工艺方案设计.实现了知识的多种描述形式及其应用,有效地解决了工艺方案设计中基于图形、规则及经验知识的决策判断,提高了汽车覆盖件工艺方案设计的智能化程度.     

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。     

覆盖件模具特征约束模型及其应用

针对覆盖件模具设计的复杂性、灵活性、经验性、模糊性.提出了一种基于特征的分层的约束模型.覆盖件模具特征分为冲压工艺特征、功能组合特征和基元特征三个层次,与此相应建立了分层的约束网,并叙述了其推理过程.     

汽车覆盖件冲压工艺设计KBE系统中的知识表示技术

根据汽车覆盖件冲压工艺设计的特点,阐述了与汽车覆盖件冲压工艺设计有关的不同类型知识的表示方法,主要有一阶谓词逻辑、语义网络、产生式规则、框架和剧本、可视化文本和图象,以及面向对象的方法等,并比较了各种方法的优缺点.面向对象的集成知识表示等方法成功地应用于汽车覆盖件冲压工艺设计KBE系统的知识表示.     

CAD/CAPP/MRPⅡ/GT信息集成的初步研究

实现CIMS的关键技术之一是动态信息集成。奉文论述了一个CIMS雏形系统中CAD/CAPP/MRPⅡ/GT之间的信息集成技术及其实现方法。提出了在CAD系统中通过建立与工艺设计工步内容相匹配的、基于设计基本特征和工艺基本特征的特征建模技术及处理程序来实现CAD/CAPP之间信息共享的方法;论述了CAPP系坑通过与MRPⅡ系统中工艺路线管理模块之间实时信息传递来实现并行式CAPP设计的步骤;提出了在GT与MRPⅡ之间寻找一个最佳结合体——工装族制造管理系统等新思想。论文对各子系统也做了简要描述。     

汽车覆盖件冲压变形趋向性控制

汽车覆盖件冲压成形过程中的变形是非常复杂的,在进行工艺设计和模具设计时不能用计算的方法得到变形的定量分布,为此,通过对覆盖件特点的分析,提出了对汽车覆盖件冲压成形进行变形趋势分析的方法,以及控制汽车覆盖件冲压变形趋势的措施,并进行了实例分析.     

汽车覆盖件成形工艺参数多方案管理系统

基于Siemens NX平台开发了汽车覆盖件冲压成形同步模拟系统Forming Analysis Wizard（FAW）,采用UDO关联技术与参数化关联技术,实现了工艺参数多方案管理功能。该系统可以在同一工序中定义多种方案,并对不同方案的工艺参数进行有效管理,为工艺优化提供参考依据。以某后排座靠背支架模型为实例,设置多...     

小型汽车零件冲压模具设计及其发展

本文介绍了汽车覆盖件冲压模的设计要点,针对冲压模具的发展和现状以及冲压新技术的应用,根据一个冲压模具的实例,对汽车覆盖件在冲压过程中容易出现的问题进行了分析,从工艺分析、模具结构设计等几个方面详细说明了冲压模设计的重要性,为结构模具优化设计分析奠定了基础。     

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.     

面向CIMS的回转件CAPP系统的设计与实现

通过对回转零件进行特征分析与分类，引入了一种特征的代码表示结构，提出了一种基于联系的零件特征描述模型，研究了在该模型上回转零件面向ＣＩＭＳ的ＣＡＰＰ系统的设计与实现，提供了该ＣＡＰＰ的软件提供结构。     

CAD/CAPP/CAM集成系统的研究与开发

文章介绍了可实用的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编程人员共同努力,在商品CAD/CAM软件Pro/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和工步,从刀具数据库中查询刀具及切削用量,并完成各工序的工步排序。自动CAM子系统根据CAPP的结果,自动生成Pro/ENGINEER的NC工步,经过NC仿真后     

Feature-based metal stamping part and process design. Part II: stamping process planning

In metal stamping development, stamping process planning plays quite an important role for the related die design. As mentioned in Part-I [Feature-based metal stamping part and process design. Part 1: stampability evaluation, 2007, 45, 2673–2695], the feature can encapsulate comprehensive engineering information; this paper proposes to realize stamping process planning based on feature mapping. A feature mapping system, between a stamping design feature space and a stamping process feature space, has been presented. The inherent mechanism of such feature mapping has been investigated with formal representations. The substance of feature mapping is the processing of related knowledge and information. Mapping rules are established to generate the stamping operation and stamping direction. Four mapping manners (direct mapping, conjugate mapping, syncretic mapping, and sequential mapping) are presented for generating the form of process feature, through geometrical information transformation from design features. Meanwhile, considering a stamping process plan as an ordered tree, this paper has introduced how to build a stamping process plan through organizing the stamping operations mapped from design features, and an illustrative example is demonstrated.     

CAD／CAPP集成系统信息建模技术研究

通过对特征技术的分析研究，基于特征技术的建模思想，设计了一个完整的产品数据信息模型，提出了一种零件ＣＡＤ．ＣＡＰＰ集成系统数据信息模型，通过网络，实现了ＣＡＤ／ＣＡＰＰ的信息交换与集成。     

参数化模板技术在汽车覆盖件冲压模具设计中的应用

根据汽车覆盖件模具设计的经验和规则,在UG平台上将模板技术和参数化方法应用于汽车覆盖件模具的设计中,能够大大地缩短传统覆盖件模具设计的周期,达到快速响应制造.本文研究了参数化模板技术在汽车覆盖件冲压模具设计中的应用方法,并实现了一套压形模板,经过实际应用,证明该模板简化了设计过程,提高了设计效率.     

STEP-based automatic system for recognising design and manufacturing features

In the present work, a STEP-based platform-independent system for design and manufacturing feature recognition is developed. A manufacturing feature taxonomy with multiple levels, which is based on the access directions of the feature, is proposed. The system can recognise both design and manufacturing features from the lower level geometry and topology available in the STEP file. The developed system can recognise intersecting features, which is a major shortcoming of previous attempts based on neutral formats. A more complete feature relationship analysis than available in the literature is carried out to find the relationships between all the types of features. Removal volumes and access directions of the features are determined to couple the feature recognition with down line applications. Raw material geometry is also considered while recognising the features. The present system is limited to parts that can be machined on a three-axis machining centre.     

基于 STEP 标准的 CAD 与 CAPP 信息集成

说明了基于标准数据存取接口（ＳＤＡＩ）生成ＳＴＥＰ中性文件实现数据交换的基本思路，提出一个ＣＡＤ与ＣＡＰＰ系统通过ＳＴＥＰ中性文件实现信息集成的方案及一个完整的零件信息模型。最后用一个基于ＡｕｔｏＣＡＤ的特征造型系统给出了实施范例。