基于Creo2.0的三维机加工工艺设计方法

随着模型定义(model based definition,MBD)技术的发展,传统二维环境下的机加工工艺已无法满足企业要求,提出一种新的三维机加工工艺方法。通过工艺模型动态构建、工艺信息标识及标注、工艺规程设计和三维工艺输出及管理实现了基于三维模型的工艺设计;通过可视化发布、车间工艺推送等技术实现"三维模型下车间";同时使得设计、工艺、制造使用相同的数据源,突破设计、工艺、制造之间的信息不统一问题。实例分析结果证明:该方法有利于提高工艺设计的效率和准确性,具有可行性和有效性。     

基于自动识别建模特征的三维机加工工序模型的定义

在三维机加工工艺设计中,产品模型被直接用于工序设计过程中的工序模型生成,而工序模型创建效率直接制约了整个三维工艺设计的效率。为了提高工序模型创建效率,对基于自动识别建模特征三维机加工工序模型进行了定义,并且把形成零件的建模特征分成了6类,分别是边界特征、内陷特征、贯通特征、螺纹特征、环形特征及其他特征。此外,还以某典型零件为例介绍了该模型定义的应用。     

机械制造全工艺碳排放量化方法

实施低碳制造是为实现我国2020年减排任务提供重要保障,也是解决我国制造业碳排放压力大的主要途径。根据典型机加工工艺制造特点,分析了机加工工艺碳排放源,建立了包括能源碳排放、物料排放以及过程碳排放的机加工工艺碳排放评估模型,用于评估和量化机加工工艺碳排放量,为工艺决策者提供了较为准确的环境影响数据,并基于该模型,进行机加工全工艺碳排放量化。文中举例说明了该方法的有效性。     

基于3DCAPP系统的三维通用夹具库系统研究与实现

在利用三维机械加工工艺规划系统(3DCAPP系统)进行数字化工艺设计过程中,夹具设计是其重要环节,其中通用夹具应用非常广泛,利用快速建模技术(模型参数化驱动)及快速装配技术,建立三维通用夹具设计系统(3D-Fixture System)并与三维机加工工艺设计系统集成,极大地提高了工艺卡片的生成效率。     

面向三维工艺设计的PBOM 建模方法研究

文中针对三维工艺设计模式应用过程中的工艺数据管理问题,提出了一种面向三维工艺设计的工艺物料清单(Process Bill of Material, PBOM)建模方法,以该方法形成的PBOM可实现三维工艺模型等工艺数据的一致性和有效管理.分析了三维工艺设计数据管理需求,给出了PBOM的形式化描述及其模型,论述了基于装配结构树驱动PBOM节点生成、基于三维工艺索引文件实现PBOM节点与三维工艺数据关联等关键技术.文中提出的PBOM建模方法对产品数据管理系统中的三维工艺设计数据管理模块开发具有指导意义.     

三维工艺设计数据管理研究

围绕三维工艺设计过程中工艺数据的集成管理问题,分析了三维工艺设计数据的组成与分类; 在此基础上,探讨了基于PBOM的三维工艺设计数据集成关键技术以及工艺数据审签和更改方法; 最后,以雷达结构协同设计平台为例,介绍了此方法的应用情况。     

D型打结器齿盘的三维可视化研究

为可视化表达打结器齿盘的加工过程,利用SolidWorks软件建立了D型打结器驱动齿盘三维模型,通过其SolidWorks CAM模块对零件进行机加工工艺处理,并依据工程实际加工工艺过程制作了零件三维可视化加工工艺文档.相对于传统的基于二维工程语言的加工工艺卡,三维可视化加工工艺能够合理展示各零部件的加工工艺内容,使机...     

面向石油机械的机加工CAPP系统开发与应用

通过对某石油机械企业机加工生产工艺的分析,采用面向对象的技术方法,设计开发了一套机加工CAPP系统。系统集机加工工艺卡片绘制,工艺信息管理和工艺信息统计于一体,可实现工艺文件的查询、添加、修改、删除、输出等操作。同时与该企业的锻造CAPP系统及ERP系统集成,遏制了信息孤岛问题的发生,进一步提高了工艺的编制效率。     

三维工艺设计中的工艺模型创建方法

针对目前机加工零件三维工艺设计存在的工序模型可读性及建模通用性差,生成效率低的问题,提出一种基于半空间相交法的工艺模型创建方法。首先对工艺MBD模型进行定义并确立了求解表达式。接着根据逆向建模思维,从设计MBD模型开始,对各道工序中的加工特征,进行特征识别与设计信息提取。然后运用改进的半空间相交及参数化建模方法,创建各道工序的制造特征体和工序MBD模型,并将最终生成的工艺MBD模型作为工艺文件输出保存。最后,以后桥差速器壳零件为例,对所提方法的可行性进行了实例验证。     

一种三维工艺知识多粒度表示与重用方法研究

针对三维工艺设计以工序模型为核心驱动工艺设计的过程特点,提出了一种三维工艺知识多粒度表示与重用方法。首先,分析了三维工艺知识的组成,明确了工艺知识所包含的信息成分。其次,根据三维工艺设计的过程特点,提出了一种基于三级多叉树的工艺实例知识表示方法,实现了工艺知识在不同粒度的有效表示。并基于该知识表示方法,以知识节点作为检索实例,在不同知识粒度上运用基于实例的推理(Case-Based Reasoning,CBR)方法实现了工艺知识的检索重用。最后,运用实例验证了该方法的有效性。     

基于三维零件模型的工艺路线设计方法研究

针对基于三维CAD的计算机辅助工艺设计(Computer Aided Process Planning,CAPP)的发展需求,提出了一种基于三维零件模型的工艺路线设计方法。从零件三维模型中提取加工特征,建立以加工特征为核心的工艺信息模型,有利于与上游CAD以及下游CAM的集成和信息共享。在工艺信息模型基础上建立以加工元为基元的工艺决策模型,通过聚类和排序约束实现工序/工步的确定和排序,实现工艺决策过程的算法化。通过飞机双面大框零件实例说明了该方法是简单有效的。     

An integrated intelligent process planning system for prismatic parts using PC-based CAD and CAM software packages

Traditional machining process planning relies heavily on human decision making and manual calculations. The utilisation of CAM software and computers to aid machining reduces errors and planning time. A fully integrated planning system using CAD and CAM software would further increase the efficiency of process planning. The goal of this research is the automation of machining process planning for prismatic parts by integrating Autocad and Mastercam software packages using the Autolisp programming language and artificial intelligence techniques. Using only a 3D representation of the prismatic part geometry drawn in Autocad as input, the integrated system will be capable of producing NC code for the machining of the part with minimal human intervention. This system would greatly enhance the productivity of machining process planning.     

零件工艺信息的提取与加工过程的三维动态仿真

通过分析虚拟制造中数控加工仿真的相关技术,建立相关数学模型,进行了面向虚拟制造的数控加工仿真系统的研究,在VisualC++6.0开发环境下,基于DXF文件中的工艺信息,开发了以车削为主的数控加工程序自动编制系统,并基于OpenGL三维显示机制,编制了数控车削过程的三维动态仿真系统,实现了由AutoCAD二维几何模型自动编制数控加工程序,并实现三维动态仿真的一体化。利用本系统可以实现自动编制数控加工程序,并可直观、实时地检验数控程序的正确性,观察加工过程。     

Process planning and electrode wear compensation for 3D micro-EDM

This paper presents a novel multi-cut process planning method and a new electrode wear compensation method based on a machine vision system for three-dimensional (3D) micro-electrical discharge machining (micro-EDM). Front wear and corner wear of tool electrode can be measured and compensated in a direct manner by the vision system??s image processing software capabilities. Experiments have shown that corner wear ratio (defined as a ratio between the length of corner wear and electrode diameter) is linearly proportional to machining length under a fixed machining depth condition. Track overlapping between the two adjoining paths is designed appropriately according to the corner wear ratio. Experimental results not only indicate that the proposed multi-cut process planning and electrode wear compensation methods can significantly improve machining accuracy and reduce machining time for the micro-EDM process, they also demonstrate that the X?CY dimensional errors of micro-structures can be controlled within 10???m.     

基于驾驭式虚拟加工的平面二次包络蜗杆实体造型

介绍了在VBA环境下，运用虚拟加工技术开发机械零件三维实体造型的实现机制和关键技术，通过引入驾驭式控制方式实现了对仿真过程的实时控制，并通过平面二次包络环面蜗轮副实体造型程序实例，阐述了三维驾驭式实体造型的设计方法。为该型蜗轮的数控加工提供合适的数学模型及相应的CAD数据接口，达到蜗轮数字化造型的目的。     

基于加工理念的液压集成块三维CAD软件设计

在AutoCAD平台上用VisualLISP设计开发了液压集成块三维CAD软件,一改传统的二维设计方法,营造虚拟三维立体设计环境,使设计过程可视化;引入加工理念,提出了模仿集成块加工过程,进行集成块实体造型及干涉检验、在线修改的方法和手段。     

Laminated fabrication of 3D queue micro-electrode and its application in micro-EDM

3D micro-electrode used in micro electrical discharge machining (micro-EDM) is difficult to be fabricated. Based on laminated object manufacturing (LOM) process, this paper superimposed multilayer 2D micro-structures together to fit out 3D micro-electrode and applied it in micro-EDM to process 3D micro-cavity mold. Firstly, 100-μm-thick Cu foils were cut by wire-electrical discharge machining (WEDM) to obtain multilayer 2D micro-structures, and then these 2D micro-structures were connected together to fit out 3D micro-electrode through vacuum pressure thermal diffusion welding. Secondly, under the effect of 80-V voltage, 0.2-MHz pulse frequency, 800-ns pulse width, and 4200-ns pulse interval, the 3D micro-electrode was applied in micro-EDM and 3D micro-cavity mold with high surface quality was obtained. Thirdly, in order to reduce the adverse impact of electrode wear on machining precision of 3D micro-cavity mold, 3D queue micro-electrode was used to process the same 3D micro-cavity mold, in which the first electrode is for rough machining and the others for fine machining. Finally, based on the above studies, two kinds of 3D queue micro-electrodes were fabricated, and the 3D micro-cavity molds with surface roughness Ra?=?0.48 μm were obtained through micro-EDM. Compared with the scanning 3D micro-EDM process, the 3D micro-cavity mold can be obtained through up and down reciprocating method of the 3D queue micro-electrode, featuring simple machining process and high efficiency.     

UG二次开发在加工工艺信息形象表达中的应用

结合当前CAPP的相关研究理论成果，针对回转体零件，提出了在UG环境下进行实际开发应用的可行性方案，并详细介绍了UG二次开发在加工工艺信息表达中的应用过程及其关键技术。     

Tolerance chart balancing with a complete inspection plan taking account of manufacturing and quality costs

This paper introduces a mathematical model of tolerance chart balancing for machining process planning under complete inspection. The criteria considered in this study are based on the combined effects of manufacturing cost and quality loss, under constraints such as process capability limits, product design specifications, and product quality requirements. Manufacturing costs include the machining cost, part cost, inspection cost, reworking cost, and replacement cost. The machining cost is expressed in geometrical decreasing functions, which represent tolerances to be assigned. Process variability is expressed in quadratic loss functions, which represent the deviation between the part measurement and the target value. An example is presented to demonstrate the proposed model. A comparison made with previous methods shows that the proposed model minimizes the total cost of manufacturing activities and quality-related issues in machining process planning, particularly in the early stages. Moreover, the applications are not be limited to machining process planning but can also be used in other forms of production planning.     

基于三维模型的雷达结构件数字化检测技术应用

雷达产品三维设计技术的不断完善与应用,对产品制造检验提出了更高要求,传统的检验方法和手段难以满足数字化研制环境下的质量保证要求。文中概述了基于三维模型的检测技术的发展,通过具体实例说明了三维数字化检测的流程与应用方法。以数字化技术手段代替传统的手工测量,解决了数字化环境下基于三维模型的检测难题,可在保证雷达产品数字化生产质量方面起到一定的作用。