基于VERICUT的炮管膛线数控建模与加工仿真研究

渐速膛线电解加工的阴极研制需要通过实验反复修正,试验难度大,研制周期长.根据加工对象的几何参数和弹道方程建立数学模型,在UG中建立炮管膛线设计模型,在Pro/ E中建立阴极工作齿和炮管毛坯的几何模型,并导入VERICUT,同时设置机床、夹具等数学模型和数控系统,添加刀具的轨迹G代码,进行加工过程的仿真,通过仿真检验设计的阴极齿形状是否合理以及修正加工过程中出现的过切或欠切等问题,以优化刀具.研究表明,在阴极设计中采用VERICUT是可行的途径.     

汽车同步器接合套倒角加工过程设计与仿真系统开发

通过对汽车同步器齿端倒角结构和加工原理的分析,抽出了与刀具参数、机床调整和加工精度相关联的要素.对于平面倒角首先建立了加工过程的几何模型,然后推导出数学模型,建立了倒角形状参数与机床调整参数之间的联系.对于曲面倒角,首先建立了刀具的几何和数学模型,然后建立了倒角加工过程的几何与数学模型,将两者相结合,研究了刀具几何参数设计的求解方法,并在此基础上开发了确定刀具调整参数的计算机仿真系统.     

基于神经网络的数控加工物理仿真的研究

为描述数控加工过程的物理现象及其规律,提出数控加工物理仿真内容体系结构,综合考虑多种影响因素运用人工神经网络分别建立起刀具磨损、切削力、温度场、切屑形态和切削振动的仿真模型,该模型大大地提高了数控加工仿真的真实性.最后指出了物理仿真的发展趋势.     

基于功率信号的异形螺杆加工刀具磨损建模

通过对异形螺杆加工过程刀具磨损状态的分析,提取了能够反映刀具磨损状态的功率信号特征值,并建立了信号特征值与刀具磨损量之间的映射关系,从而得到刀具磨损模型.实验证明,由此建立的刀具磨损模型能够排除切削参数变化的干扰,可以较好的反映加工中刀具磨损状态,为刀具磨损在线补偿提供了重要的理论依据.     

基于物理仿真模型的螺旋立铣刀建模

加工过程仿真是验证加工程序正确性、预测加工过程表现及产品质量的一种有效手段,它由几何仿真和物理仿真组成.但是现今的CAD/CAM软件几乎没有提供实用的物理仿真功能.文章针对现有数控加工仿真中物理仿真的功能不准确的问题,提出了能满足物理仿真要求的刀具的建模理论和方法.在该理论的指导下,利用Visual Basic6.0和OpenGL建立了螺旋立铣刀支持参数库和铣刀模型,并成功的嵌入了天津大学数控铣床的仿真软件中.     

基于NC物理仿真的钛合金薄壁件颤振预测研究

针对钛合金薄壁零件在铣削加工过程中存在的切削颤振问题,以多框类零件为对象,建立了基于NC物理仿真的钛合金薄壁零件颤振预测模型,解决了钛合金零件在工艺准备初期即实现颤振的预报。首先通过试验与仿真相结合的方式,获取工艺系统的颤振稳定域,并进行稳定域内参数优化;其次通过建立有限元模型,进行零件模态分析,获取零件加工过程中的动态特性,确定最优刀具路径;最后利用NC物理仿真软件对零件进行切削过程仿真,预测切削过程中颤振是否发生。结果表明,通过此类技术,可直观有效地跟踪加工过程,提高薄壁件加工稳定性。     

考虑刀杆柔性的球头铣刀数控加工表面误差模型的研究

通过将刀具的铣削力分解为x、y、z方向的分力,同时考虑刀具本身的柔性,提出了球头刀加工过程表面误差模型.结合加工过程中常用的刀具路径,将实测的切削力应用到误差模型与实际测试得到的误差进行对比,以证实模型的有效性,并通过实验得出了一些有用的结论.     

基于UG的高速雕刻机加工仿真系统的研究

应用UG软件IS&V模块,针对JZDK6040高速雕刻机,建立与实际加工一致的精确运动模型与加工仿真模型,对CAM生成的刀具轨迹程序进行模拟、校验和显示,监控机床、工件和刀具之间的碰撞干涉情况,有效避免实际机床加工过程中误切、过切等现象的发生。     

基于VERICUT的机床建模和数控车削加工仿真技术

VERICUT是专为制造业设计的CNC数控机床加工仿真和优化软件工具。文章应用VERICUT建立机床、刀具和工件及夹具三维模型,用数控程序驱动机床运动部件,仿真加工过程,校验数控程序,防止产生废品。     

数控机床虚拟样机的虚拟加工实现

虚拟加工是对数控机床虚拟样机进行性能测试的内容之一。本文在UG IS＆V环境下建立了一台三轴数控铣床的仿真模型。在该模型的基础上分别对零件加工过程中的刀具路径和铣床运动进行仿真,在虚拟样机上实现了虚拟加工。通过虚拟加工分析,可对设计的机床进行性能预测和评价,进一步完善初步设计。     

Virtual EDM simulator: Three-dimensional geometric simulation of micro-EDM milling processes

In this paper a three-dimensional geometric simulation method of micro-EDM milling processes is proposed, which introduces a Z-map algorithm to precisely represent the geometries of a machined workpiece and the evolution of the tool shape caused by tool wear during the machining. The micro-EDM milling process is mathematically and geometrically modeled. In order to verify the performance of the developed simulator, an actual square cavity is machined and compared to the simulation result. The developed EDM simulator can be used for tool path generation for tool wear compensation as well as for prediction of tool wear.     

Tool wear-dependent process analysis by means of a statistical online monitoring system

Simulating milling processes can provide numerous optimization possibilities regarding process stability and surface quality. In tool and die manufacturing often long-running processes are necessary. In contrast to very time-consuming Finite-Element-based approaches, geometric physically-based simulation systems allow predictions for such processes because of their relatively short runtime. The machining of hardened material and varying engagement conditions between the tool and the workpiece provoke a gradually increasing influence of tool wear on the cutting edges. To consider these alterations while simulating milling processes, different approaches can be used. Because of the complex characteristics of tool wear, methods, which result in an increased simulation runtime, have to be used for the geometric modeling of tool wear. In this paper, a novel approach for monitoring a milling process is presented, which utilizes an online-selection of pre-calculated simulation data to predict the process stability for different states of tool wear. To achieve this, measured data are compared to simulated data, which result from offline simulation conductions for each defined state of tool wear. As tool wear changes when the process is progressing, different simulation data for different states of tool wear have to be selected to ensure a valid stability prediction.     

DSX5—70型三杆五自由度并联虚轴机床的运动仿真

基于开发研制的三杆五自由度并联虚轴机床，概述了实现虚轴机床三维实体模型数控加工的运动仿真方法，利用开发的虚轴模块，解决了在虚轴机床上实现CAD／CAM集成的难题，实现了三杆虚拟轴机床CAD／CAM的一体化、软件的模块化设计，使仿真系统具有良好的扩展性和通用性，操作方便。     

Geometry prediction of EDM-drilled holes and tool electrode shapes of micro-EDM process using simulation

EDM is an efficient machining process for the fabrication of a micro-metal hole with various advantages resulting from its characteristics of non-contact and thermal process. However, this process has a serious problem caused by the tool wear, which significantly deteriorates the machining accuracy. In this paper, a geometric simulation model of EDM drilling process with cylindrical tool is proposed to predict the geometries of tool and drilled hole. The geometries of tool and workpiece are represented by two-dimensional matrix. For accurate prediction of their geometries, the tool motion, the sparking gap width, the spark frequency, the crater made by a single spark, and the tool wear ratio are considered as simulation parameters. To verify the simulation model the prediction results are compared with the actual experimental ones. Consequently, it is shown that the geometry prediction results match the experimental ones well within the error of 13%. Developed model can be used in offline compensation of tool wear in the fabrication of a blind hole. For the purpose of this, a compensation scheme based on the developed model is introduced, it is then demonstrated that the scheme is successfully applied to an actual micro-hole machining.     

Simulation of parallel kinematic machine tools with minimal effort

New innovative machine tool concepts like parallel kinematics require the development process to be continuously supported by simulation. Otherwise it will be impossible to exploit their full potential due to the complexity of the kinematic and dynamic behavior. Nevertheless, machine tool manufacturers often refrain from employing simulation tools because of the high effort and expenses expected for the introduction of this technology. It is against this backdrop that the paper presents a method to support the development process of parallel kinematic machine tools with a minimum of effort. An analysis of the development process identifies the machine characteristics that have to be determined for each stage. A simulation method is developed based on these results and on the requirements for a seamless integration of the simulation techniques into the different stages of the process. It is implemented and tested by the example of a parallel kinematic machine tool that has already been successfully introduced in industry.     

Improved NC path validation and manipulation with augmented reality methods

Five-axis milling offers many advantages over the conventional three-axis milling process. However, because of the potentially complex motions, it is difficult for the machine tool operator to anticipate the actual movement based on the NC program. In this paper a software system for the NC path validation and manipulation during the milling process is introduced. This system is meant to expand the information given to the machine tool operator by enriching the view with data of a concurrently running milling simulation. The simulation is synchronized with the real-world machine tool movement by detecting the position of a marker that is mounted on the head stock. With this combination of real-world view and computer-generated data, which is called Augmented Reality, the machine tool operator is able to detect critical situations—like collisions between tool holder and workpiece or excessive forces—and may adjust the NC program accordingly.     

Simulation of milling tool vibration trajectories along changing engagement conditions

This paper presents a simulation system, which is able to model engagement conditions as a syntactical geometric model along arbitrary NC-programs. This modeling approach allows the feedback of tool deflections into the model of the chip form, which enables the simulation of regenerative tool vibrations along changing engagement conditions. Methods from the field of computer graphics allow a fast analysis of the chip forms as well as a fast cutting force calculation, which is essential to speed up this time-domain simulation system. Experiments show a good agreement of calculated and measured tool trajectories even along sudden changes of the radial immersion. Furthermore, a geometric model of the workpiece is applied, which is able to represent the surface structure resulting from a vibrating cutting tool. Thereby, chatter marks as well as the effects that occur along changing engagement conditions can be modelled and rendered realistically.     

Advanced Tool Edge Geometry for High Precision Hard Turning

The hard turning process has been attracting interest in different industrial sectors for finishing operations of hard materials. However, it still presents disadvantages with respect to process capability and reliability. In this paper the impact of PcBN tool edge geometry is investigated based on a modelling as well as an experimental approach. The hard turning process is described by means of a 3D simulation of the tool engagement based on the Finite Element Method. The simulation results indicate force and temperature distribution in the tool-chip contact zone for different designs of PcBN tool cutting edge, thus allowing the derivation of criteria for an advanced tool edge design.The recommendations for tool edge geometry modification are experimentally verified. The results suggest that the use of the proposed new tool edge geometry is an effective way to significantly increase tool performance with respect to tool life, material removal rate and part surface quality in high precision hard turning.     

Life Cycle Simulation System for Life Cycle Process Planning

To realize closed loop manufacturing, it is essential to design product life cycles and to plan life cycle processes property. Life cycle simulation has been recognized as an effective tool in this direction. In this paper, we present a life cycle simulation system developed as a general tool for life cycle design and management. The system includes functions for modelling and controlling each life cycle process in a flexible manner. The system maintains usage history of products and parts independently taking the reuse of parts into account. Examples of the simulation are shown for both a rapid life cycle scenario and for a part sharing scenario over the product generations.     

一种数控机床故障模拟装置的开发及应用

针对数控装置开发过程中测试工具欠缺的现状,以总线式数控装置为研究对象,分析了数控机床故障模拟的技术特点,提出了一种基于构建机床逻辑模型的故障模拟技术,开发了一套专用的故障模拟装置.并通过对华中数控HNC-08数控系统进行故障模拟实验验证.实验结果表明该装置满足数控装置测试故障自诊断功能的需求,有效的提高了测试效率及安全性.