考虑刀具磨损的数控车削批量加工工艺参数节能优化方法

在数控车削批量加工过程中,刀具磨损的加剧会导致能量消耗显著增大.针对现有节能优化研究忽略了刀具磨损状态和工艺参数对能耗的协同影响的问题,提出一种考虑刀具磨损的数控车削批量加工工艺参数节能优化方法.首先,分析刀具磨损和工艺参数对数控车削批量加工能耗协同影响机理;基于此,以批量加工总能耗最低和完工时间最小为目标,以不同刀具...     

数控刀具的参数化设计

讨论了应用参数化技术设计数控刀具的步骤及方法,介绍了新开发的数控刀具设计平台,应用该平台可大大提高数控刀具的设计效率。     

基于专家系统的数控刀具选配系统的研究

在数控刀具选配实现过程中,采用专家系统的基本原理,使数控刀具选配更加方便与简洁。本文详细研究数控刀具事实库、规则库以及数控刀具选配系统推理机的设计方法,并建立了基于专家系统的数控刀具选配系统模型。最后提出数控刀具选配方案的评价方法。     

基于功能分解的数控刀具相似性设计的研究与实现

研究了数控刀具的设计特点 ,以产品设计功能树表达其基于功能分解的设计过程 ;采用辅助面切割法进行几何体素的造型 ,以适应不同的功能需求 ,然后按照功能分解的反方向对几何体素进行拼合完成刀具的造型过程。此外还采用编码匹配查找的方法实现数控刀具的相似设计 ,从而大大提高了数控刀具的设计效率和设计质量     

基于网络优化的复杂型腔刀具轨迹规划算法

复杂型腔零件的加工是数控编程中的一个难点。从提高加工算法的稳定性和加工效率的角度出发,提出了基于网络优化的复杂平面型腔数控加工刀具轨迹优化算法,分析了轮廓环的等距、自交、集合运算等基本运算,详细论述了基于网络优化的刀具轨迹规划方法并优化了刀具轨迹。     

刀具磨损感知数据驱动下的DBN预测模型研究

针对制造车间数控刀具在连续作业过程中易出现过度使用或提前置换的现状,对刀具磨损感知数据获取方法和磨损预测模型构建进行研究.为避免传感器噪声影响,采用OPC技术直接与机床协同完成数控通信,并设计一套双镜头垂直分布的感知数据获取系统;为增强预测模型泛化能力,采用Dropout优化后深度信念网络(DBN)作为预测模型,先在特征提取阶段重构出优化权值,再引入标签量训练特征匹配阶段.结果 显示,改进的DBN算法平均预测准确度约96.0％,在预测精度和稳定性方面较传统模型显著改善.     

带内冷却钻铰一体刀具的研制

阐述了钻铰一体复合刀具的设计,并且详细地介绍了复合刀具的数控加工方法。通过切削实验固化了数控磨床砂轮参数及型号的选择;通过设计制造钻铰复合刀具可以提高钛合金材料的加工质量。钻铰复合刀具的使用,提高了孔加工的效率及质量,具有推广价值。     

基于图元法的数控立铣刀CAD

针对数控铣刀种类多,结构复杂,而传统的刀具设计效率低的特点,在图元拼合法理论的基础上,对立铣刀的结构进行深入分析,建立了数控立铣刀图元库,并应用AutoCAD二次开发技术,建立铣刀CAD系统平台,实现了数控刀具的参数化设计,并实现刀具参数优化、工程图纸自动生成、刀具库管理等功能,缩短了刀具设计周期,提高了设计质量.     

数控刀具管理编码系统的设计与开发

依据数控刀具的工艺、结构及材料等特征信息,结合实际刀具管理的需要,对数控刀具进行信息的分类和排序,采用字母与数字混合的方式进行了数控刀具编码系统的设计与开发,使刀具编码包含了数控刀具所有的特征信息与管理信息,确保了刀具编码符合唯一性、适应性、稳定性、可扩充性、可识别性和可操作性原则,满足了生产过程中数控刀具管理的需要。     

基于Intranet的数控加工信息管理系统的研究

网研究设计了数控设备网络的DNC管理系统,确定了加工信息管理系统的总体框架与主要功能模块.确定了数控机床管理子系统、机床任务管理子系统、数控机床通信管理等6个模块,并以刀具管理系统为例说明了数控集成生产管理系统信息模型的设计与实现.     

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.     

CIMT’97主要展品的技术特点综述

两年一度的中国国际机床展览会是国际机床界和我国机械制造业的一件盛事。第五届中国国际机床展览会(CIMT’97)又一次荟萃了国内、外各机床厂及相关配套件厂和工具厂的精华,既可看到一些名牌企业享有盛名的产品,也会发现一些脱颖而出的新秀企业所展示的精品。从展览会上我们能深刻地领会到机床工具行业的发展动向,也能生动地观察到琳琅满目的新产品和新结构。从中既反映了丰富多采的世界先进实用制造技术和最新制造技术,也展示了中国机床工具行业通过“三大战役”在增强开发能力和竞争实力方面所取得的可喜的巨大进步。     

Reliability estimation for cutting tools based on logistic regression model using vibration signals

As an important part of CNC machine, the reliability of cutting tools influences the whole manufacturing effectiveness and stability of equipment. The present study proposes a novel reliability estimation approach to the cutting tools based on logistic regression model by using vibration signals. The operation condition information of the CNC machine is incorporated into reliability analysis to reflect the product time-varying characteristics. The proposed approach is superior to other degradation estimation methods in that it does not necessitate any assumption about degradation paths and probability density functions of condition parameters. The three steps of new reliability estimation approach for cutting tools are as follows. First, on-line vibration signals of cutting tools are measured during the manufacturing process. Second, wavelet packet (WP) transform is employed to decompose the original signals and correlation analysis is employed to find out the feature frequency bands which indicate tool wear. Third, correlation analysis is also used to select the salient feature parameters which are composed of feature band energy, energy entropy and time-domain features. Finally, reliability estimation is carried out based on logistic regression model. The approach has been validated on a NC lathe. Under different failure threshold, the reliability and failure time of the cutting tools are all estimated accurately. The positive results show the plausibility and effectiveness of the proposed approach, which can facilitate machine performance and reliability estimation.     

Post-Processor Development for a Six Degree-of-Freedom Parallel-Link Machine Tool

A coordinate system with multiple non-orthogonal axes, defined for a parallel-link machine tool is very different from that for a conventional serial-type machine. Therefore, a special post-processor that can automatically transfer the cutter location data (CL-data) into machine specific NC commands is essential for real machining applications of a parallel-link machine tool. Parallel-link machine tools have been investigated by many previous workers. However, work on the theory of post-processors for this machine tool is very sparse, and most is focused on the orthogonal serial motion. The potential benefits of the parallel-link machine tools make work necessary and urgent on the transformation of the CL-data from a CAD/CAM system into NC commands for special parallel-link machine tools. A six degrees-of-freedom (DOF) parallel-link machine tool constructed as a 6-3-3 mechanism was selected in this work to investigate the theory of post-processing, and the effects of the cutter shapes and the machine construction on it. The parametric representations of different cutter shapes defined by the DIN standard were adopted in the work, increasing the usefulness of the post-processor theory developed. Specific parameters must be modified in the post-processor for different tools applied for real cutting. The tilt angle and yaw angle of the cutter, relative to the normal direction of the cutting surface, is also included in the theory. Finally, the NC code is generated using LabVIEW software, and simulations were performed to investigate the correctness based on several designed tool paths.     

Evaluation of machinability according to the changes in machine tools and cooling lubrication environments and optimization of cutting conditions using Taguchi method

This study analyze the effect of machine tools, cooling lubrication environments and cutting conditions on surface roughness and cutting force, and propose the combination of cutting conditions which minimizes the effect of machine tool variables on the dispersion of cutting force and surface roughness by treating the changes in machine tool itself and the installation environments as a noise factors. To do so, the Taguchi method is used to establish an experiment plan, and flat end milling is carried out to measure cutting force and surface roughness. The research results show that in the case of cutting force, the effect of cutting conditions is dominant, and changes in machine tools and cooling lubrication environments barely have effect on cutting force. However, in the case of surface roughness, all of the cutting conditions, machine tool and cooling lubrication environment variables have impact. In order to select a combination of cutting conditions insensible to changes in machine tools, considerations for feed per revolution and axial depth of cut turn out most important in the aspect of cutting force, and considerations for feed per revolution is most important in the surface roughness.     

数控机床的现代造型风格与设计

通过分析机床造型风格的演变过程，研究了数控机床现代造型风格的主要特征，并对其未来的发展趋势做简单探讨。同时，通过数控镗铣虚拟轴机床XNZ63的造型设计实例，说明了造型风格在数控机床产品造型设计中的具体应用。     

数控机床主轴部件动态优化设计

在对某型数控车床进行空运转、切削及模态试验的基础上，确定了机床主轴部件动刚度薄弱是引起机床切削的结构颤振方面的原因。据此，建立了机床主轴部件的有限元动力学模型，并对主轴部件进行了静、动特性的计算和动态优化设计。     

Monitoring and control of tools in multifunctional machine tools

Machining centers and multifunctional machine tools are used in computerized integrated production. They are equipped with a large number of cutting tools for production of a specific batch of parts. In such automatic systems, monitoring and control systems replace the human operator. Monitoring of the state of machining systems is essential today in monitoring and control of the machining operations [1, 2]. It is important to create monitoring systems to support reliable tool operation in multifunctional machine tools. The goals of such systems are to minimize the damage from serious disruption of tool operation and to ensure timely tool replacement. To that end the multifunctional machine tools and/or the numerical control system must be equipped with sensors and various monitoring devices. A strategy must be developed for the prevention of disruption of the machining process and tool failure.     

刀具磨损寿命分布规律的现场验证

通过对数控机床加工情况的现场调查，验证了关于刀具磨损寿命分布规律的研究成果，分析了刀具可靠性对切削加工过程的影响，建立了应根据刀具的可靠性来决定换刀间隔和切削用量，并提出了提高刀具可靠性的具体措施。     

内冷却钻头在数控机床上的选用

在数控机床上使用内冷却钻头，可以提高切削速度、刀具寿命和加工质量，使数控机床的功能得到充分利用；在深孔加工中使用效果更为显著．