电解车削加工流场的数值模拟及工艺试验研究

针对电解车削加工的流场设计,基于内喷式阴极结构和电解液流道的物理模型建立了相应的数值模型,应用计算流体力学方法进行求解,得到了流场的速度和压力分布。根据求解结果,分析了阴极内部结构对流场的影响;通过改进阴极的内部结构,得到了相对较好的模拟结果;结合工艺试验,验证了数值模拟的准确性,表明可将计算流体动力学的方法用于流场的模拟和指导阴极结构的改进设计。     

典型数控车削零件的工艺方案设计

首先阐述零件在加工前需要完成工艺设计,制定工艺文件的重要性。然后选择具有代表性的轴类车削加工零件,通过分析图纸的加工内容及加工要求,初步拟定加工工艺路线。根据所拟定的加工工艺路线,完成细节的设计,包括设计辅助夹具、选择合适的刀具以及切削用量。最后形成加工工艺方案,填写工序卡和完整的加工工艺卡。展示了典型轴类零件的加工工艺方案设计全过程。     

数控车削加工工艺探究

在数控车削中,为了确保工件的加工效率和加工质量,就必须在加工之前对工件认真仔细地进行工艺分析,从而制定出合理的工艺方案,编制出正确、高效的加工程序,同时采取有效的工艺措施,实现工件高质量、高效率的加工.     

第五讲 数控车削工艺

数控车削加工花键轴。数控车削加工轴承座。零件数控加工编程任务与加工要求参见第1讲。零件装夹、数控车削刀具、切削用量解析参见第2至4讲。 1数控加工花键轴零件的工艺分析 1．1结构分析 在数控车削加工中,零件花键轴的车削加工成型轮廓的结构形状并不复杂,但零件的尺寸精度尤其是零件的几何精度要求较高。     

数控车削轴类零件工艺的设计

数控机床是计算机高新技术产品,综合应用的高速,高精度加工技术可以大大提高工作效率和产品质量,缩短生产周期和提高市场竞争力.而对于数控加工,在编程前都要对所加工的零件进行工艺分析,拟定合适的加工方案.在这个过程中采取的控制精度的方法加工出合格的产品.加工精度高的工件过程时,数控车床车削加工时工艺的编排就十分重要了,不同的加工工艺,加工出来的产品也不一样,可见数控车削工艺设计的重要性.     

高性能等级螺纹的数控车削工艺

介绍了用经济型数控车床车削加工高性能等级三角螺纹的方法,并以华中I型数控系统加工M24三角螺纹为例,具体分析了螺纹粗、精车进刀方法、局部螺纹循环程序的实现和螺纹加工程序的编制与调试。     

球形阴极数控电解加工的流场仿真及试验研究

针对球形阴极数控电解加工的流场设计,以电解液的流道为物理模型建立了相应的数值模型,应用计算流体力学方法对流场的数值模型进行求解,得到流场的速度和压力分布。根据求解结果,分析了阴极内部结构和出液口形状对流场的影响;通过改进阴极的内部结构和出液口形状,得到了较为理想的流场仿真结果;结合工艺试验,验证了仿真结果的准确性。     

数控车削加工讲座 第六讲 数控车削工艺相关知识概述

1选择确定数控车削加工的内容 通用机床无法加工的内容应该作为首选内容。通用机床难以加工和质量难以保证的内容应该作为重点选择内容。一般说来,上述这些加工内容采用数控加工后,在产品质量、生产效率和综合经济效益等方面都会有明显的提高。此外,在选择数控车削加工内容时,还要考虑到生产批量、现场生产条件、生产周期等情况。     

基于有限元法的球形数控电解加工工艺试验研究

针对球形阴极数控电解加工中成形规律分析较为困难的问题,提出了基于有限元法的电解加工过程模拟方法。在ANSYS中建立了球形阴极电解加工二维电场的分析模型,并对加工过程的模型进行求解计算,得到了阳极表面不同时刻的电流密度分布和表面形状。以过程模拟参数为基础进行了工艺试验,并将得到的试验值与理论计算值进行了对比,结果表明:该方法可以满足工程计算的精度要求,为深入开展球形阴极数控电解加工过程的研究提供了方法和理论依据。     

Design of continuity processes of electrochemical finishing and grinding following turning

A newly designed finishing process utilizing an effective electrode and a grinding tool to execute the continuous electrochemical finishing and grinding processes following turning is described in this paper. The proposed process can be used for a variety of turning operations. Electrochemical finishing and grinding can be performed following the finishing process on the same machine by using a simple attachment. The factors affecting electrochemical finishing, grinding performance, and electrochemical finishing are discussed. The electrode was tested with both continuous and pulsed direct current. A higher work piece rotational speed produced a better finish. Changing the electrode design from a semicircle to a wedge form with a small end radius caused the electrolytic products and heat to dissipate more rapidly and provided the best finishing. Pulsed direct current finishing was slightly better than using continuous direct current finishing. However, the use of pulsed current would increase machining time and cost. This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim Dr. P.S. Pa obtained his doctorate at National Tsing Hua University, Taiwan. Presently he is an Associate Professor at Graduate School of Toy and Game Design of National Taipei University of Education. His fields of interest are innovative design and manufacturing processes. His current research includes ECM process for mould and die materials, precision finishing, toy design, and electro-optical engineering.     

Machining and dimensional inspection of spatial cams on 5-axis machine tools

An analytical methodology is developed for NC data generation to produce and measure spatial cams on 5-axis machine tools. The Denavit-Hartenberg notation is used for expressing the ability function of the employed machine tool and in the generation of the desired cutter/measuring-probe location. NC data equations are determined by equating the corresponding elements of the machine tool's ability function to the desired tool location matrices. To validate this methodology, a designed cam was machined and its surfaces were measured by an online measurement system equipped with a touch-trigger probe on a 5-axis machine tool. The resultant cutting speed and material-removal rate during machining are also investigated. This methodology is a general one and is applicable to various spatial cams. It also combines the activities of design, manufacturing, and measurement, thus making the production process more flexible, automatic, and controllable.     

浅谈数控机床的故障诊断与排除

随着数控技术的发展，数控机床在机械制造业中得到了广泛的应用，其普及率越来越高。但由于数控机床技术复杂，一旦出现故障，维修难的问题严重影响了数控机床的有效利用。因而，本文结合实例，阐述了数控机床故障的诊断与排除方法，对数控机床的操作人员、管理人员、尤其是维修人员具有很好的借鉴作用。     

型材翻面机设计与研究

阐述型材翻面机各部分结构、运动分析及三维建模,并对翻面机构工作原理、行走机构、升降机构、设计方案和齿轮齿条传动完成翻面的新型结构形式作了介绍.     

我国机床数字控制技术的回顾和发展

数字控制技术是20世纪最伟大的工程技术发明之一,已发展成为对制造技术发展有着深远影响的共性工程技术.论述机床数字控制技术的意义,对比纺织工业的织机,回忆我国数控机床的诞生,总结归纳我国机床数字控制技术的发展历程,并提出我国在数字控制技术发展中的数字控制机床、加工中心和柔性制造生产线三个里程碑.介绍了1958年我国第一台数控机床研制过程以及早期我国数控机床的发展情况.分析了我国机床数字控制技术发展中存在的问题,提出了相应的对策.     

Optimisation of surface roughness on turning fibre-reinforced plastics (FRPs) with diamond cutting tools

Fibre-reinforced plastics (FRPs) are used in structural components in various fields of application of mechanical engineering, such as automobile, biomechanics and aerospace industries. Their own properties, particularly the high strength and stiffness and simultaneously low weight, allows the substitution of the metallic materials in many cases. As a result of these properties and potential applications, exist a great necessity to investigate the machining of these composite materials.This paper presents an optimisation study of surface roughness in turning FRPs tubes manufacturing by filament winding and hand lay-up, using polycrystalline diamond cutting tools. A plan of experiments was performed with cutting parameters prefixed in the FRP tubes. The objective was establishing the optimal cutting parameters to obtain a certain surface roughness (R_a and R_t/R_max), corresponding to international dimensional precision (ISO) IT7 and IT8 in the FRP workpieces, using multiple analysis regression (MRA). Additionally, the optimal material removal rates have been obtained.     

Theoretical and experimental study of the chatter vibration in wet and MQL machining conditions in turning process

Turning is one of the most commonly used cutting processes for manufacturing components in production engineering. The turning process, in some cases, is accompanied by intense relative movements between tool and workpiece, which is called chatter vibrations. Chatter has been identified as a detrimental problem that adversely impacts surface finish, tool life, process productivity, and dimensional accuracy of the machined part. Cooling/Lubrication in the turning process is normally done for some reasons, including friction and force reduction, temperature decrement, and surface finish improvement. Wet cooling is a traditional cooling/lubrication process that has been used in machining since the past. Besides, a variety of new cooling and lubricating approaches have been developed in recent years, such as the minimum quantity lubrication (MQL), cryogenic cooling, nanolubrication, etc., due to ecological issues. Despite the importance of cooling/lubrication in machining, there is a lack of research on chatter stability in the presence of cutting fluid in cutting processes. In this study, the chatter vibration in turning process for two cooling/lubrication conditions of conventional wet and MQL is investigated. An integrated theoretical model is used to predict both the metal cutting force and the chatter stability lobe diagram (SLD) in turning process. This model involves deriving a math equation for predicting metal cutting force for both wet and MQL conditions using experimental training force data and a Genetic Expression Programming (GEP)-based regression model. Also, the traditional single degree of freedom chatter model is used here for predicting the SLDs. The chatter model is discussed and verified with experimental tests. Then, the experimental results of the tool's acceleration signal, work surface texture, surface roughness, chip shape, and tool wear are presented and compared for wet and MQL conditions. The results of this study show that the cooling/lubrication systems such as wet or MQL have a considerable effect on the SLDs. Also, the predicted results of metal cutting force and SLD for both wet and MQL techniques are in good agreement with the experimental data. Therefore, it is recommended that for each lubrication condition including wet, or MQL, the SLD be determined to achieve higher machinability.     

基于虚拟样机技术的数控机床现代设计方法

讨论了基于虚拟样机技术的数控机床设计流程，分析了以三维实体建模软件PRO／E、机械动力学仿真软件ADAMS、大型有限元分析软件ANSYS和控制仿真软件MATLAB／SIMULIINK为核心的数控机床虚拟样机实现的集成软件平台，以数控钻铣床为例，将虚拟样机技术应用于机床的设计开发，对开创数控机床工程设计新方法具有重要的意义。     

机器视觉的电解车削对刀间隙检测

研究基于机器视觉的电解车削对刀间隙的检测方法。构建由CCD模拟摄像机和视频采集卡组成的图像采集和转化系统,利用VC++6.0开发相应图像处理软件,并通过对间隙图像的处理获得对刀间隙的实际尺寸值。     

快速检查机床电器故障的方法

了解机床的功能,掌握设备的原理,弄清元、器件的位置,熟悉它们的机、电关系是快速检修机床电气故障的关键。