五坐标水切割中的刀具补偿方法

针对五轴水切割自动编程和加工问题,提出五轴水切割的刀具补偿方法.采用五坐标刀具长度补偿法控制五轴水切割靶距;刀具长度补偿值适应喷嘴长度调整.通过分析三维刀具半径补偿与刀位轨迹计算的一致性,利用刀具半径补偿法初步规划五坐标水切割刀位轨迹曲线.应用结果表明,刀具补偿法对解决五轴水切割加工靶距控制是切实可行的,且解决了水切割编程工具的问题.     

基于宏程序的电子对刀仪在加工中心的应用

分析对刀仪的结构和工作原理,设计对刀宏程序,实现自动对刀、自动设定或更新刀具的长度补偿值,并根据实际情况增加安全警报、状态保护功能.同时设计连接部分硬件.采用上述方案实现了电子对刀仪在加工中心上的安装和使用,提高了在加工中心进行刀具长度补偿的精度和效率;并节约了购买软件的成本.同时将该方案用于课程教学.增强了学生对数控机床辅助设备安装维修能力.     

刀具订单自动生成系统的研发

刀具订单自动生成系统是车间刀具管理系统的一个重要组成部分。研发了基于B／S模式的刀具订单自动生成系统，提出了两种刀具需求订单自动生成算法：（1）TS（Technics and schedule）算法，即根据工艺信息及生产计划自动生成刀具需求量；（2）IVF（Inserting value forecast）算法，即根据历史记录值自动生成刀具需求量。该系统已成功应用于某机械加工企业，经测试。，结果表明该系统在实际机械加工生产中具有较强的自适应性，降低了刀具的采购成本，并很好地保证了生产的连续性。     

数控加工深型腔复杂型面模具的刀具长度优化

介绍数控加工深型腔复杂型面模具时刀具长度优化的几种方法,通过最短刀具长度的计算、旋转零件降低型腔深度、拆分零件加工模具以及使用刀具加长杆和角度头,实现缩短加工刀具的长度、优化加工手段,提高模具的加工精度、质量和效率。     

CIMS中MasterCAM刀具信息的自动集成

用MasterCAM的二次开发工具C-Hooks对其进行了二次开发.开发了能自动从工艺数据库中获取刀具编号,再根据编号从刀具数据库中获取刀具信息,并向MasterCAM中添加刀具信息的C-Hooks应用程序,给出了该程序的流程.实现了CIMS中MasterCAM刀具信息的自动集成.     

成组刀具的自动更换装置

本文一般应用于多轴机床,特别适用于具有自动转换器实现整套换刀的多轴机床。本文详细介绍多轴机床的自动化换刀以及主轴装备自动化松开与夹紧的装置。 文中所介绍的换刀机构,能使多轴机床的各轴与刀具库之间实现成组刀具的更换。在刀具库的许多组刀具之中所预选的那一组能同时和主轴上的刀具作自动成组互换。这种多轴刀具转换器还能将所选刀具分别夹紧在各旋转轴中。 文中所介绍的主轴自动定位及自动松开与夹紧装置,能使各主轴稳定地保持在预选位置,以配合多轴刀具转换器的应用。由于采用了成组刀具的自动更换装置,多轴机床大大地提高了实际加工的应用范围及效率。     

数控加工中的刀具补偿

提出了刀具补偿的作用，着重介绍了刀具长度补偿和半径补偿的实现方法。     

基于夹具规划系统的机床和刀具自动选择研究

针对基于特征的夹具自动规划设计系统，讨论了如何自动确定加工过程中的机床及刀具的方法，以MDT为运行平台，利用VC＋＋、Object ARX、Microsoft Access等软件工具，开发建立了常用的加工中心和机加工刀具数据库和自动选择机床刀具子系统，并用实例验证了其可行性。为夹具自动设计的实现奠定了基础。     

数控渐进反向成形支撑凹模STL模型生成与制作

为满足金属板材数控渐进反向成形中支撑凹模制作的需要,提出一种从板材件的CAD模型自动生成并可根据加工要求实现自动调整尺寸大小的支撑凹模STL模型,该模型可以根据已有坯料尺寸、刀具长度等因素自动进行实体分层以及支撑凹模整体制造和分层制造。最后,以具有多个较复杂曲面的STL模型为对象,给出了支撑凹模STL模型生成实例和利用四轴数控雕铣机制作支撑凹模实例。     

刀具磨损的测量与自动补偿

论文主要介绍了利用CCD测量被加工工件尺寸的工作原理以及压电传感器逆压电效应的工作原理。阐述了CCD测量工件直径的理论、方法和压电传感器组的结构和工作过程。详细论述了该测量控制系统是如何进行实时、动态和自动监控、测量被加工工件的尺寸变化；以及系统是如何根据工件尺寸的变化来判断刀具的磨损情况，根据测量结果来自动发出刀具过度磨损信号，并自动驱动系统控制压电传感器根据磨损情况来确定刀具的补偿量，从而完成对刀具磨损的自动补偿。     

CNC机床指示输入及其系统

CNC机床指示输入是依据机械加工人员的操作习惯而设计的加工程序自动生成模式，CNC机床操作人员用加工任务指示器指示机床的运动部件和刀具，在完成加工过程空运转及试切的同时自动生成数控码，文章论述了实现这种方法的系统构成，运动参数的输入与处理。     

Milling force prediction using a dynamic shear length model

Modelling of cutting forces in milling is often needed in machining automation. In this paper, a new method for the determination of the cutting forces in face milling is presented, which applies a predictive machining theory originally developed for orthogonal cutting to milling operations, with a dynamic shear length model developed and incorporated. The proposed dynamic shear length model is developed based on the analysis for the true tooth trajectories of a milling cutter, taking into account of the characteristic wavy surface effects in milling. The prediction for the cutting forces is carried out at each step of the angular increment of cutter rotation from input data of fundamental workpiece material properties, tool geometry and cutting conditions. Cutting forces at a cutter tooth can be predicted once the shear angle, shear length, shear plane area, and the shear flow stress along the shear length have been determined. The milling force prediction using the dynamic shear length model is verified through milling experimental tests. The sensitivity of the difference between the static and dynamic shear length models with respect to the feed per tooth and the cutter diameter is discussed.     

基于PC的数控火焰切管机床研制

在对数控火焰切管机床的加工原理和割炬路径的运动学分析基础上,研制了一种功能强大的火焰切管数控机床.设计了相应的计算机程序,能够根据切割类型和参数直接定义加工程序;构建了开放式、模块化的数控系统平台,实现了高质、高效、自动切管.     

Investigation of Cutting Characteristics in Side-milling a Multi-thread Worm Shaft on Automatic Lathe

This paper investigates the cutting characteristics of side-milling which is proposed as a more efficient way to manufacture worms of higher accuracy than form-threading and planetary milling. A tool-tip trajectory based on the tool-workpiece interaction is modelled in terms of matrix transformation. Chip thickness, cutting force and surface roughness are simulated using the calculated tool-tip trajectories. The effects of various errors in the real cutting such as run-out errors of a tool axis, tool setup errors and workpiece deflection due to cutting forces are investigated. The simulation results are verified through numerous experiments on an automatic lathe.     

Tool wear model based on least squares support vector machines and Kalman filter

In this study, the least squares support vector machines (LS-SVM) and Kalman filter (KF) technique are used to establish the tool wear estimation model. Tool wear prediction model, based on LS-SVM, is given to describe the mapping relationship between input–output factors. The cutting conditions (feed rate, cutting speed, and depth of cut), cutting time, and wear position constitute the input factors and tool wear is the output parameter of the model. In order to improve the accuracy of the LS-SVM results, the KF technique is used to update the tool wear estimated results of LS-SVM-based model, which is called the LS-KF model, according to the measured tool wear values. Experiment work is performed on machining center for cemented carbide ball-end cutter cutting stainless steel. Those two models (LS-SVM model and LS-KF model) are applied to the actual milling machining to verify their performance. Results show that predicted tool wear based on the proposed LS-KF model has more precision than that of LS-SVM model.     

An analytical model for the optimized design of micro-textured cutting tools

Proper design of micro-textured cutting tools is an effective strategy to improve the machining performance by reducing the tool-chip contact length and the resultant friction and thus improving tool life and workpiece surface integrity. In this paper, an Oxely-based analytical model is developed to optimize micro-textured cutting tool design(s) which eliminate the occurrence of derivative cutting. The model accommodates any workpiece material, tool geometry, and machining parameter. The model was validated by orthogonal cutting of AISI 1045 steel tubes. The results show that the optimum micro-texture design eliminates derivative cutting and lowers forces compared to the non-textured cutting tool.     

一种新型测温刀具的研制

采用磁控溅射法在PCBN刀具的前刀面上镀制NiCr和NiSi薄膜,形成一种新型的NiCr-NiSi薄膜热电偶测温刀具。详细阐述了薄膜热电偶的制作过程,结合WS-2005涂层附着力自动划痕仪和Jsm-5610扫描电子显微镜分别测试分析了NiCr和NiSi薄膜的附着力和成分。通过现场切削试验表明,制备的NiCr-NiSi薄膜热电偶测温刀具能够实时、快速、准确地测量切削温度。     

锥度线切割机床微机控制系统的开发

将两轴联动的线割机床改造成四轴联动，即增加了u轴和v轴的联动时可切割锥度体的线切割机床的微机控制系统。重点介绍了锥度控制原理、齿隙补偿、端偏量补偿、短路回退，并分析了对称、旋转加工的数据自动生成方法。     

A study of micropool lubricated cutting tool in machining of mild steel

This paper presents an experimental study of the performance of micropool lubricated cutting tool in machining mild steel. Microholes are made using femtosecond laser on the rake face of uncoated tungsten carbide (WC) cutting inserts. Finite element analysis is conducted to assess the effect of microholes on the mechanical integrity of the cutting inserts. Liquid (oil) and solid (tungsten disulfide) lubricants are used to fill the microholes to form micropools. A comparative study is conducted between micropool lubricated (surface-textured) cutting tools and dry/flood-cooled conventional (untextured) cutting tools. Three cutting force components are measured and compared. Tool–chip contact length and chip morphology are examined using optical microscope. It is found that the mean cutting forces (F_f, F_t, and F_c) are reduced by 10–30% with micropool lubrication. The chip–tool contact length is reduced by about 30%. Coiling chips are produced with micropool lubricated cutting tool while long and straight chips are formed with the conventional cutting tool. Liquid and solid lubricants are found to be equally effective in reducing the contact length and coefficient of friction at the chip–tool interface. There is no adverse effect on the performance of the insert with microholes on the rake face.     

Theoretical and experimental investigation of the frictional behavior of the tool–chip interface in ultrasonic-vibration assisted turning

The frictional behavior of the tool–chip interface has a significant role in the cutting mechanics. The frictional and normal forces, the contact length between the cutting tool and chip, the coefficient of friction and the stress distribution are the influential parameters. The behavior of the tool–chip interface in ultrasonic-vibration assisted cutting is different from conventional cutting and needs to be investigated. The ultrasonic-vibration assisted cutting has several advantages compared with conventional process. In the present study a frictional model has been developed for studying the above mentioned parameters and predicting the tool–chip behavior in ultrasonic-vibration assisted turning at different cutting speeds and vibration amplitudes. The results have been verified by experiments.