基于MDT的组合夹具CAD系统中元件选择及精度计算实现

组合夹具由不同形状、不同规格尺寸的标准元件组装而成。夹具设计过程中工艺人员在组装角度夹具和一些基本功能结构时,通过选取同类元件的多个不同系列尺寸装配形成一个组合尺寸。基于MDT软件和组合夹具CAD系统,开发了夹具设计中组合尺寸元件选择和精度检验的实现方法。     

基于虚拟现实的组合夹具组装系统研究

针对计算机辅助组合夹具设计存在的问题,提出了一个基于虚拟现实的组合夹具组装系统。给出了系统的功能模型和体系结构,研究了组合夹具虚拟装配模型、虚拟环境下组合夹具元件的装配定位等关键技术和解决方案。提出了基于多视图的组合夹具虚拟装配模型,该模型便于信息表达和管理,符合虚拟环境的表达和组织原则,解决了元件重复使用问题。提出了基于模糊评判的几何约束自动识别方法,对待装配件与装配基准件的装配特征进行匹配和优化选择,实现装配操作意图的准确捕捉。应用实例表明,原型系统能够很好地支持组合夹具组装设计。     

基于Pro/M的组合夹具结构分析

组合夹具作为一种先进的柔性工艺装备,特别适用于数控机床、加工中心等先进制造单元,是今后夹具技术发展的一个重要方向。组合夹具由一整套标准元件组装而成,用有限元法计算其在切削力和夹紧力作用下的应力应变,以模拟夹具在实际加工过程中的变形,提高夹具设计水平。Pro/Mechanica是Pro/ENGINEER的一个有限元分析模块,可以实现与三维CAD软件Pro/E的无缝集成,能有效提高装配体有限元分析的效率。因此,基于Pro/Mechanica进行组合夹具结构分析,可及时发现设计缺陷,缩短夹具研制周期,提高效率。     

基于SolidWorks的夹具功能组件库的建立研究

组合夹具是由不同核心组件组装而成的,将基于知识系统原理和可重构性原理引入组合夹具计算机辅助设计中,提出了基于核心功能组件库的计算机辅助组合夹具设计方法.该方法针对组合夹具组件模型库的建立开发出相应的资源管理,可以实现对组件库的查阅、选择、读取、建模等功能,以适合现代制造的需求.     

计算机辅助夹具设计系统的研究与实现

在对国内外夹具设计的现状进行分析的基础上 ,针对槽系组合夹具和专用夹具的设计特点 ,在Unigraphics的平台上以VC ++6 .0为集成开发环境 ,以VisualFoxpro6 .0为数据库平台开发了基于特征造型、参数化驱动的三维夹具设计CAD系统。系统介绍了计算机辅助夹具设计CAD系统的设计思想、总体框架、实现的技术方案。     

精确、快速调整组合夹具的研究与应用

在孔系组合夹具元器件的开发基础上,研制了过渡性连接件和调整件,扩大了槽系组合夹具的应用范围,实现了孔、槽系结合的组合夹具精确调整,提高了组合夹具的精度与稳定性,保证了产品质量;同时应用软件建立了组合夹具元器件和柴油机零件三维模型数据库,实现了组合夹具计算机模拟组装及信息管理,为柴油机数字化制造奠定了基础。     

计算机辅助组合夹具组装设计

介绍我院自行开发的计算机辅助组合夹具组装设计软件包，该软件包采用了绘图法和检索法相结合的设计方法，利用本软件包，组装人员可在计算机上进行组装设计，并由绘图仪输出组合夹具的装配图。     

计算机辅助夹具设计CAD系统的研究

在对国内外夹具的设计现状进行分析的基础上，针对槽系组合夹具和专用夹具的设计特点，在Unigraphics的平台上以VC 6．0为集成开发环境，开发了基于特征造型、参数化驱动的三维夹具设计CAD系统。介绍了计算机辅助夹具设计CAD系统的设计思想、总体框架、实现的技术方案。     

组合夹具计算机三维智能组装系统

将CAD和人工智能技术引入组合夹具设计中，可以提高生产效率、减轻劳动强度、缩短生产准备周期和加快产品上市时间。介绍了组合夹具计算机辅助设计的发展情况和研制的智能型组合夹具计算机辅助组装系统的结构及其功能，重点对系统中的智能模块做了阐述。     

基于UG的组合机床夹具智能设计系统的研究与应用

介绍了组合机床夹具设计的研究状况,分析了企业开发应用组合机床夹具智能设计系统的必要性及该系统实现存在的难点。在分析构建该智能设计系统的系统框架的基础之上,利用三维设计软件UG的OPEN二次开发功能及其WAVE技术的相结合,开发实现了该系统,并对实现该系统的关键技术进行了详细的阐述,主要包括夹具知识库的建立及夹具体等非标准灵活性零件的设计过程等。最后进行了工程应用,结果表明该系统能提高组合机床夹具设计的效率和质量。     

CAFD中的夹具快速装配技术研究

近年来CIMS中的CAD、CAPP、CAM技术得到了长足的进展 ,然而基于CAD模型的夹具自动设计的研究还相对薄弱 ,尤其是夹具的自动装配技术。本文引入了有效表面和有效路径的概念 ,建立了快速装配模型 ,给出了功能结构及详细的夹具装配算法流程 ,为组合夹具的快速装配提供了一种切实可行的方法     

FIX-DES: A computer-aided modular fixture configuration design system

This paper presents a computer-aided modular fixture configuration design system: FIX-DES. When fixturing requirements are specified as locating/clamping surfaces and points, a fixture configuration will be automatically generated by

1. Selecting fixture elements from a fixture element database to form fixture units based on fixture element assembly relationships.
2. Placing the fixture units and elements into position on a baseplate while the fixturing requirements and assembly relationships (e.g. hole alignments) are maintained.

The fixture element assembly relationships can be established automatically when the geometric models and fixturing functions of the fixture elements are specified so that the FIX-DES system can be applied easily to different fixture systems. The system also provides the interactive design and design modification functions for human expert involvement. The system was developed with core programs in C and C++ and interface programs in a specific CAD environment. The system has been successfully applied in industry and can be transferred easily to other CAD systems. The overall structure of the FIX-DES system is introduced in the paper. The development of the automated fixture configuration design (AFCD) functions are presented in detail. Finally a fixture configuration design example is given to illustrate the application of the system.     

孔系组合夹具三维构形自动生成研究

采用ObjectARX语言开发了具有夹具特征和装配特征的参数化的孔系组合夹具元件库,并基于夹具特征和专家系统,建立了一种自动确定定位和夹紧区域的孔系组合夹具构形图自动生成系统,并阐述了有关算法主要思想.     

A systematic conceptual design of modular fixtures

The replacement of dedicated fixtures by modular fixturing systems seems to be a trend in the manufacturing field, especially in meeting the desire for greater flexibility but the selection of appropriate modules from a modular fixturing system and subsequent assembly is itself not an easy task. This research provides a systematic design method to help dedicated fixture users to convert to modular fixturing system users. This method classifies modules into five functional groups and then selects proper modules from each group in accordance with the functional request of the fixture assembly. This systematic design of modular fixtures helps a dedicated fixture user to build an economical and efficient modular fixturing system.     

基于交互式平台的三维组合夹具设计系统

为了提高组合夹具设计的效率和质量,从实用性和易用性的角度出发,以SolidWorks2001Plus和Windows2000作为支撑环境,利用Visual C 6.0、Access2002等开发工具,应用面向对象的程序开发方法,构造了一个组合夹具设计系统.为设计人员进行组合夹具设计提供了一个软件辅助工具,使其能够在软件的帮助下顺利完成组合夹具的设计.     

An adaptive control system with self-organizing fuzzy sliding mode control strategy for micro wire-EDM machines

Collision detection is a fundamental component to simulate realistic and natural object behaviors in virtual reality-based system. In this paper, a hybrid method of space decomposition and bounding volume approach is presented to assist modular fixture assembly design in a virtual environment. Based on characteristics of modular fixture, a novel space decomposition methodology at object level is proposed, which is achieved by automatically partitioning the checking space into cells according to the oriented bounding boxes of assembled elements after the initial approximate collision detection using the intersection checking method based on separation plane-based bounding box. Then the pairs of candidate objects are determined for narrow phase exact polygons overlap tests. Results from several performance tests on modular fixture design system show that an important advantage of this proposed method compared with other universal algorithms is its simple information representation and low preprocessing cost.     

Development of Automated Fixture Planning Systems

Fixturing is an important manufacturing activity. The computeraided fixture design technique is being rapidly developed to reduce the lead time involved in manufacturing planning. An automated fixture configuration design system has been developed to select automatically modular fixture components and place them in position with satisfactory assembly relationships In this paper, an automated fixturing planning system is presented in which fixturing surfaces and points are automatically determined based on workpiece geometry and operational information. Fixturing surface accessibility, feature accuracy, and fixturing stability are the main concerns in the fixture planning. The system development, the fixture planning decision procedure, and an implementation example are presented in the paper.     

Representation of similarity and dependency for assembly modularity

Researchers have expanded the definition of product modularity from function-based modularity to life-cycle process-based modularity, and developed a measure of product modularity and validated a corresponding modular product design method. However, a correct modularity measure and modular design method are not enough to realize modular product design. How the measure and design method are used, especially the role of product representation, is an important aspect of modular design and imperative for realizing the promised cost savings of modularity. In this paper, we develop a representation that includes similarity and dependency for assembly modularity. The similarity representation is based on assembly cost factors including tool changes and fixture changes. The process-based design dependency representation is based on design features that impact the assembly process (faces, fasteners, assembly interference, etc.). This representation captures the cost benefits of modularity and can be extended to other life-cycle processes. A set of products is used to show the application of this representation in association with a modularity measure and modular design method.     

A Fast Interference Checking Algorithm for Automated Fixture Design Verification

Fixtures are tooling devices used to locate, support and hold workpieces during a manufacturing process. The major purpose of a computer-aided fixture design (CAFD) system is to provide a fixture design based on fixturing principles and workpiece information. Interference checking between the machining tool and fixture units, as well as between fixture units, is one of the important functions of automated fixture design. This paper presents a fast interference checking algorithm for automated modular fixture design validation. It is based on the study of the geometric characteristics of modular fixture components and the machining tool. The fixture component model is simplified into a 2D contour model with height information. The tool-path model is represented by a moving dot for 3-axis operations, or a moving line segment in 5-axis operations, as the fixture component model is different from the popular collision detection procedure using swept volume and is more efficient for fixturing verification. Application of this method will greatly reduce the computation complexity for fixturing interference checking. The method is implemented with a CAFD system. An example is given at the end of the paper.