孔系组合夹具夹紧方案自动规划方法

提出了基干实体模型的工件夹紧点自动确定方法和夹紧信息表示方法。采用了工件外轮廓的规约化方法,根据工件的规约化几何形状,确定工件满足夹紧要求的夹紧点个数,再进行夹紧点位置区域划分。从每个区域中各选择一个夹紧点组成一个夹紧方案,形成了可行夹紧方案集合。根据夹紧点位置、高度与受力多边形关系,来评价夹紧方案。     

一种孔系组合夹具定位方案自动确定方法

提出了一种在孔系组合夹具上一般工件定位方案的自动确定方法。该方法首先确定前两个定位销在基础板上的位置。此时基础板上两个定位销可在工作的两条定位边界上滑动，基础板与工件的组合可以看作一个连杆机构，基础板相对于工件作连杆平面运动，基础板上其它定位孔中心在工件的定位边界所在平面上的轨迹均为连杆运动曲线，利用连杆运动曲线与工件的定位边界求交来确定定位方案的第三个定位点，该方法适用于孔系基础板、圆柱定位销的组合夹具。     

孔系组合夹具定位方案通用设计方法

提出一个面向孔系组合夹具的定位方案通用设计方法,该方法的通用性体现在以下几个方面:1)工件的侧面定位 基准可以是平面和圆柱面,以及两者的各种组合。2)定位元件的类型可以是圆柱销和V形块、半V形拼块,以及同一次 装夹中采用不同形式定位元件的混合定位。3)可以进一步扩展到适用于任意曲线柱面作为定位基准。     

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.     

基于RFFS映射模型的组合夹具构形设计

从夹具功能的分层表达策略入手,建立了夹具需求-功能-特征-结构(Requirement-Function-Feature-Structure,RFFS)映射模型,并建立了工件装夹的面域网络模型,同时研究了组合夹具构形设计中的重要资源夹具元件库和夹具元件装配关系库的构建.     

敏捷夹具CAD系统组成与自动构形设计方法研究

介绍了敏捷夹具系统组成,阐述了敏捷夹具的层次表示结构,提出了计算机辅助敏捷夹具自动构形可行的研究方法。     

孔系组合夹具的零件定位方案自动确定方法

提出了一种孔系组合夹具的一般定位方式,该定位方式包括工件定位边与定位元件之间接触边的类型及其组合形式,每一个定位方案由3个固定在基础板上的定位元件组成,其中定位元件包括圆柱销和半V形定位块以及两者之间的各种组合。提出了建立定位方案集合的实施算法,将3个定位元件在基础板上的位置问题分解为两个步骤。首先根据2个定位边的类型和位置,确定2个定位元件的所有可能位置集合,然后根据给定3个定位边以及其中2个定位边上的定位元件位置和类型,确定第3定位元件全部可行定位位置集合。该方法可用于建立孔系组合夹具可行定位方案集合。     

一种自动定心夹紧车床夹具的设计

分析了汽车转向柱管底座产品的工艺特点,阐述了该类零件车床夹具的结构设计,对于采用盲孔自动定心夹紧夹具的设计有一定的借鉴作用。     

组合夹具设计的几何原理

提出孔系基础板组合夹具设计的系统方法。该方法利用连杆机构原理自动确定由直线和圆弧组成定位边界的零件的全部候选定位方案。根据３个定位销和工件轮廓边界的几何关系，提出将工件装卸运动分为平移装卸运动和旋转装卸运动两种运动形式，并提出定位销可见锥概念和定位销转动支点概念，进行定位方案的装卸可行性分析和定位质量分析。根据对３个定位销的反作用力之间的几何和力学分析，进一步提出瞬心三角形概念和同向边概念，并利用这些概念进行工件的可夹紧性分析，确定工件边界的可行夹紧边范围。     

一种随动夹紧装置

根据要求,需将图１所示螺纹连接工件拆开。该工件Ａ端可在机器旋卸夹头上夹持,但Ｂ端为光滑圆柱面,没有扳手槽,螺纹连接端涂有强力粘胶并打有铆点,旋卸扭矩很大。按一般方法夹紧时,常因夹紧力不够而造成打滑,费时费力,无法满足大批量生产的要求。为此,设计了以下装置,顺利解决了问题。如图２所示,该机构主要由底座１、拉簧４、左丝母座５、偏心轮６、丝杠７、右丝母座９及Ｖ型钳口１０等组成。旋卸时,将工件８Ａ端装夹在机器旋卸夹头上,Ｂ端放入偏心轮和Ｖ型钳口之间,转动丝杠,使偏心轮和Ｖ型钳口夹住工件,不用使劲,只需带…     

基于SOLIDWORKS配置技术的组合夹具参数化设计

基于组合夹具的特点,灵活运用SOLIDWORKS2003的配置技术,介绍了一种组合夹具的参数化设计方法和实现步骤,应用表明,本方法具有很强的实用性.     

Automated fixture configuration using projective geometry approach

The geometric and topological specification of a workpiece boundary is usually represented in a specific data format in a CAD database. To retrieve a set of workpiece data, to analyse its shape in addition to the machining requirements, and to determine the proper fixture configuration accordingly, are not trivial tasks when a part has a complicated shape. The real challenge is to recognise and synthesise the shape of a workpiece from its data representation. Consequently, the decision for fixturing can be made when the shape of a workpiece and the relationship of the shape and the fixturing configuration can be derived by a systematic methodology. In this paper, a projective spatial occupancy enumeration (PSOE) approach is applied as a representational and manipulating scheme for developing algorithms in automatic fixture configuration. The workpiece is projected onto the working plane of the fixture baseplate. A 2D projection is defined as a matrix of cells which can represent a workpiece with an arbitrary shape. Using a discrete search based upon the matrix of cells, the fixture types and their locations are generated according to a set of heuristic algorithms. This work is a generalisation and extension of previous works for prismatic parts. The same methodology is equally applicable in general robot grasping.     

An expert system for fixturing design for face milling using modular fixture

The research objective of this paper is to develop an expert system for a modular fixture. We provide a complete fixturing procedure analysis for workpieces with different shapes such as L, I, T, and U types. In this system AutoCAD is used to draw the workpiece; then the data for points, lines, and faces are dealt with. Using the knowledge presentation method, the clamping position of the modular fixtures, the kinematics constraint balance and the fixture and cutting forces are determined. Integer programming is used to arrive at an optimal arrangement. In addition, the system provides a learning concept incorporating knowledge from experience and heuristic rules to enable repeated self-learning to compensate for the lack of knowledge. Finally, some examples are demonstrated.     

组合夹具装配虚拟设计

介绍了一个基于ＰＣ的组合夹具虚拟装置设计系统（ＶＤＭＦＳ）的开发过程,并分析探讨了该方法的不足及以后开发的方向。     

Development of a computer numerical control (CNC) modular fixture — Machine design of a standard multifinger module

This paper presents the first phase of our ongoing development of a computer numerical control (CNC) modular fixture involving the machine design of a standard multifinger module. The aim is to develop a modular fixture which consists of only one type of standard multifinger CNC module which can provide locating, supporting and clamping functions. The module consists of four fingers with eight degrees of freedom to conform to any arbitrary workpiece surfaces. The eight motions of the four fingers are controlled by one motor through the use of two transmission and clutch systems. Different fixture layouts or reconfigurations can be made by different combinations of a multiplicity of such modules for major product family changes; while adjustments to finger positions of individual modules can be made by direct computer numerical control for minor product changes within a product family. The machine design and operation of the module are presented in the paper. A prototype was built and tested and satisfactory performance was achieved. Finally, two examples are provided to illustrate the flexibility and use of the standard multifinger module.