基于面向对象技术的CAPP工艺建模研究

采用面向对象技术描述汽车半轴类零件的整个加工过程，建立半轴类零件的加工特征模型，将其抽象成为一个半轴零件类，类中封装了零件的管理信息、几何信息、工艺信息和加工信息等，并将这个模型转换为数据结构模型，利用数据结构的理论和方法对特征模型进行表达，从而达到对零件的整个加工过程的描述．该技术不仅提高了CAPP系统的柔性化程度，而且为CIMS的信息共享提供方便。     

面向工艺决策的箱体零件特征信息模型的研究

文章对面向工艺决策的箱体零件特征信息模型进行了研究,论述了面向工艺决策的完整的零件信息模型在CAPP系统中的作用,论述了面向工艺决策的完整的零件信息模型的内容和要求,以箱体零件为例,对箱体零件的工艺设计过程和规律进行分析,依据零件工艺决策的要求,按照CAPP系统的结构,提出了箱体零件特征信息模型的总体结构,重点阐述特征层的组织和表达,提出了将特征层信息用图的形式加以描述,以方位为单元,以基本特征+组合特征的混合特征为特征单位,基本特征和组合特征内部再分解成简单特征子图,用边表达特征间的关联关系,建立面向工艺决策的箱体零件特征信息模型.     

面向可制造性评价的航空发动机叶片零件信息模型研究

针对可制造性评价的工程需求,基于广义特征和STEP标准建立叶片零件信息模型,并在UG软件二次开发的基础上,实现了一个基于特征的CAD系统.基于所建立的零件信息模型,系统可自动生成STEP文件,为设计的后续可制造性评价提供丰富的叶片零件信息,便于实现CAD与后续过程的集成和并行.利用建立的叶片零件信息模型,实现了CAD/CAPP/DFM的信息集成.     

自动机加工智能CAPP系统的研究

通过研究引信和钟表小轴类零件基于知识和实例的表示方法,建立了面向对象的零件几何、工艺特征信息描述方法.应用面向对象的技术构造了工艺决策过程的分层规划结构和支持CAPP系统决策过程模型,实现了零件加工工步的自动排序、工步参数的自动计算、切削用量的自动确定及工艺资源的自动决策,动态实现了工艺文件的自动生成,该系统已在生产实践中得到了较好的应用.     

箱体类零件CAPP与NC编程集成系统研究

文章从分析箱体类零件CAPP系统的特点出发,在系统研究箱体类零件的信息描述、加工特点的基础上,开发出实用型CAPP系统——NDCAPP系统。该系统主要应用在柔性制造单元的箱体类零件加工。NDCAPP系统以特征造型技术为基础,提出了“基本实体 方位特征”描述法,并把零件信息存储在专用的数据库中,在自动生成工艺过程和NC加工代码时,直接从数据库中读取几何信息,并自动转换为加工所需要的坐标信息,较好的实现了CAPP/NC编程的集成。     

创成式CAPP系统中基于特征的零件信息模型研究

针对创成式CAPP系统对零件信息描述的要求，分析了零件特征信息的种类和特征之间的关系，建立了基于特征的易于计算机处理的零件信息模型．文章提出了形状特征的分类原则，并以回转体奖零件为例，介绍了零件信息描述的过程。设计了友好的零件特征信息人机交互输入界面，使零件信息输入直观、简便，具有一定的实用性。     

集成产品特征映射与可制造性分析

设计与制造的集成是实现集成产品设计的关键,采用制造特征的产品模型定义可以完整准确地表示零件的加工制造信息.提出采用加工过程"切削特性"的制造特征的表示方法,建立了零件制造特征的动态模型.通过对特征间映射规则的研究,实现了形状特征向制造特征的映射.开发的特征映射与可制造性分析系统,验证了制造特征的表达与特征映射技术的可行性,为CAPP中产品模型的表达提供了有效解决途径.     

解决CAPP零件信息输入的根本方法—产品特征建模法

零件信息的描述和输入是建立CAPP系统的前提。本文首先讨论了目前CAPP系统零件信息输入的三种主要方法,指出了各自的局限性。在此基础上,从整个CIM集成角度出发,提出了基于形状特征的产品建模技术。它从根本上解决了CAPP零件信息输入问题。文章概略地介绍了产品模型的基本结构和组成,强调了形态特征在产品建模中所起的重要作用。最后,分析了产品模型的CAPP应用情况。图2幅,参考文献6种。     

面向机械产品的零件分类编码系统设计

零件分类编码是实现派生式或创成式CAPP的核心内容.文章介绍了一种零件分类编码系统--PowerCode系统,它通过编码完整地描述零件特征信息,解决了零件工艺设计过程的自动化问题,适应了派生式或生成式CAPP系统的发展趋势,为企业制造业信息化集成奠定了良好的基础.     

非回转体零件CAD/CAPP集成系统中工序图的自动生成

本文以特征造型贯穿于CAD和CAPP中，介绍非回转体零件CAD/CAPP集成系统中工序图的自动生成方法及零件信息的描述方法。     

TWEM, a method based on cutting forces—monitoring tool wear in face milling

One of the most important objectives in manufacturing is the intelligent machining system. To come to such a solution, the tool wear has to be determined on-line during the cutting process on unmanned machining systems. This contribution discusses the results experimentally obtained in face milling with a new rotating dynamometer. The paper introduces the concept of tool wear indicators which can be determined by simple analysis of the feature parameters of cutting force signals. The disturbance of the cutting force signals obtained by using the rotating dynamometer can be solved by applying tool wear indicators such as Normalized Cutting Force indicator (NCF) and Torque-Force Distance indicator (TFD). The Method for Tool Wear Estimation—TWEM is proposed.     

激光切割加工中CAPP系统的设计与研究

介绍了一种激光切割加工中CAPP系统工艺数据库设计与开发，该系统可以提供激光切割加工的各种加工方法和工艺参数的选择，实现激光切割工艺标准化，并为智能化工艺设计提供了基础。     

基于Pro/E模型的制造特征提取技术的研究

目前，CAD／CAPP的无缝集成问题是制约当代制造业发展的关键。文章尝试运用自动特征识别技术和交互特征定义技术相结合的混合法来实现从CAD的设计域到CAPP的制造域的特征转换，从而建立完善的CAD／CAPP智能接口，在一定程度上很好的解决CAD／CAPP的集成。     

Active brazed ceramic cemented carbide compound drills for machining lamellar graphite cast iron

The optimum and efficient way of machining is linked to the choice of the most appropriate cutting tool and cutting tool material. High performance cutting ceramics are characterized by excellent hardness properties at elevated temperatures. For this reason, cutting ceramics meet the requirements for machining with high cutting speeds to increase process productivity. Whereas cutting ceramics are widely used in turning and milling operations, their use in drilling processes, using ceramic insert tipped tools, is limited to larger diameter applications due to design restrictions. Beyond small diameters, solid ceramic tools were of negligible interest for industrial applications owing to their excessive tool manufacturing costs. This paper presents a new tool concept which addresses this challenge and permits a more productive machining process for drilling small diameter holes using ceramics as the cutting material. An active brazed compound drill combines the advantageous properties of ceramics and cemented carbide as the cutting tool material and basic holder material, respectively. The investigations presented here describe the manufacturing chain as well as the application of a compound drill, and compares it to a widely used industrial reference tool.     

The selection of tools and machines on web-based manufacturing environments

Tools and machines selection is one of the most important activities in process planning. Computer-aided tool selection (CATS) has been a vital element in Computer-aided process planning (CAPP) systems. However, the selection of tools and machines is a dynamic activity between planning and scheduling. Most CAPP systems focus on the generation of static process plans via incorporated manufacturing knowledge and they are not flexible to connect with existing manufacturing resources. In addition, there is an increased demand for CATS to frequently communicate with design in manufacturing environments for manufacturability evaluation. This paper discusses the selection of tools and machines on Web-based manufacturing environments. It helps existing CAPP systems to generate realistic and economical process plans, and lets designers efficiently undertake manufacturability evaluation. In particular, the machine selection incorporated with tool selection can generate extended strategies for economical production. An example is presented to illustrate the method proposed.     

涂层刀具微喷砂表面处理技术的进展

介绍了微喷砂表面处理技术进展及工作原理,分析了微喷砂处理对涂层刀具表面完整性、切削性能的影响。研究发现,微喷砂能够改善涂层刀具表面的粗糙度并提高涂层表面的残余压应力,进而提升刀具的切削性能并延长使用寿命。总结了微喷砂表面处理技术对涂层刀具表面的影响,并且对微喷砂表面处理技术进行了展望。研究结果为涂层刀具的表面处理和绿色智能制造提供了参考。     

Simulation based model for tool life prediction in bevel gear cutting

Due to unpredictable tool life behavior in bevel gear cutting, unexpected production stops for tool changes occur. These lead to additional manufacturing costs. Because of its complexity, it is currently not possible to analyze the bevel gear cutting process sufficiently regarding tool life. This restriction leads to an iterative process design and determination of the ideal process parameters by using a trial-and-error approach. As a matter of fact, there is no concept to predict tool life in bevel gear cutting. Thus, a project has been initiated in order to develop a tool life model based on cutting simulation. This report presents the tool life model which combines a manufacturing simulation for bevel gear cutting with a regression model. The data of the regression model are determined by analogy trials. The combination of manufacturing simulation and regression model allows a local tool life prediction along the cutting edge.     

A Study on Micro-Machining Technology for the Machining of NiTi: Five-Axis Micro-Milling and Micro Deep-Hole Drilling

Micro-sized applications are gaining more and more relevance for NiTi-based shape memory alloys (SMA). Different types of micro-machining offer unique possibilities for the manufacturing of NiTi components. The advantage of machining is the low thermal influence on the workpiece. This is important, because the phase transformation temperatures of NiTi SMAs can be changed and the components may need extensive post manufacturing. The article offers a simulation-based approach to optimize five-axis micro-milling processes with respect to the special material properties of NiTi SMA. Especially, the influence of the various tool inclination angles is considered for introducing an intelligent tool inclination optimization algorithm. Furthermore, aspects of micro deep-hole drilling of SMAs are discussed. Tools with diameters as small as 0.5 mm are used. The possible length-to-diameter ratio reaches up to 50. This process offers new possibilities in the manufacturing of microstents. The study concentrates on the influence of the cutting speed, the feed and the tool design on the tool wear and the quality of the drilled holes.     

基于开放式系统的曲面加工误差动态补偿控制

将基于传感器信息的智能型开放加工系统应用于曲面的高精度加工,提出了曲面加工误差的动态补偿方法。为预测加工误差的补偿量,建立了刀具弯曲模型,分析了刀具弯曲对加工误差的影响。实验结果表明,本系统可有效地提高加工精度,使加工误差降低1／3－1／4。     

Tool path optimization for free form surface machining

This article presents a novel approach to generate optimized tool paths for free form surfaces that are commonly used in automotive, aerospace, biomedical, home appliance manufacturing and die/mold industries. The developed tool path optimization approach can handle various objectives under multiple constraints. Due to anisotropic geometry of free form surfaces, tool paths become one of the most critical factors for determining cutting forces. Here, the concept of force-minimal tool path generation is introduced and demonstrated for free form surfaces. Nowadays, process planning engineers must select the tool paths only from a set of ordinary tool paths available in CAM systems. These standard tool paths available in CAM systems are generated based on geometric computations only, not considering mechanics of processes, and most often these paths are away being optimum for free form surfaces. Here, a new methodology is introduced the first time for generating the tool paths based on process mechanics for globally minimizing the cutting forces for any given free form surface.