机床加工零点夹紧系统设计与仿真分析研究

针对机床加工快速换装的需要,在建立统一工艺基准零点的基础上,设计了一套机床加工零点夹紧系统,使机床工作台具有精确定位和自动夹紧功能。通过建立零点夹紧系统动力学方程,利用有限元软件对该系统关键部件进行静态结构分析和模态分析,获取了关键部件的变形云图、应力云图、固有频率以及模态振型。基于零点夹紧系统轻量化设计要求,对其关键部件进行了结构改进和性能仿真分析。结果表明:进行铣削加工时,零点夹紧系统不会发生共振现象,验证了夹具系统设计的可行性,具有良好的工程应用价值。     

VDL1000主轴箱结构分析及改进设计

机床主轴箱的机械性能直接影响到机床的加工精度,文章以VDL1000立式加工中心主轴箱结构作为研究对象,应用有限元软件对其进行结构分析和改进设计研究,指出了其结构存在的不合理因素,并提出了改进方案,通过有限元分析对改进结构进行验证,证实了新方案的合理性.     

微小型零件的微细切削加工工艺研究

文章研究了微小型零件的微细切削加工工艺,微细切削加工微小型零件具有较大的工艺和成本优势,适应微小型零件产品批量化、加工柔性化、材料多样化的发展趋势.微小型零件按照加工工艺特征大致可分为微小型轴类、三维结构件、板类和齿轮类零件,总结和分析了上述零件的工艺特征和加工方式,介绍了微小型加工机床和刀具的选用原则,包括如何合理选择微细切削刀具的材料、特征尺寸和结构.微小型零件必须根据机床功能和零件自身结构特点确定装夹方式,并进行准确定位.最后,归纳和总结了微小型零件进行微细切削数控加工工艺设计时应遵循的原则,并进行了详细论述.微细切削加工中,采用合理的数控加工工艺和走刀路线,可以实现微小型零件的精确、高效加工,适应批量化的产品需求.     

VHT800立式车铣加工中心立柱结构静动态优化及轻量化设计

研究了VHT800立式车铣加工中心立柱结构的静动态优化及轻量化设计方法,解决了企业经验设计结构存在的静、动态性能不足以及结构过于笨重的问题.首先基于机床实际典型工况下的立柱载荷及边界条件,运用拓扑优化技术建立了体积约束下的立柱结构多工况静态性能和动态性能多目标拓扑优化概念模型;然后对概念模型进行结构刚度设计及工艺设计.最终为企业提供了新的立柱结构方案,该方案的结构刚度和一阶固有频率比经验设计结构分别提高了13.6%和17.1%,同时质量减轻了9.7%,表明该设计方法能够有效提高机床立柱结构静、动态性能并实现结构轻量化设计.     

微小型车铣复合机床模态分析

微小型零件切削加工设备精度的提高对于微小型结构件切削加工质量的提高起到巨大的作用.通过对某大学自主研制的微小型车铣复合机床KNC-50FS进行模态测试,得到该机床的低阶模态振型,并通过切削实验进行验证.模态分析结果为机床颤振研究和加工参数选择提供了基础.     

轻量化耐腐蚀复合材料铺叠模制造技术研究

介绍了复合材料铺叠模成型飞机结构件的重要性,针对目前该类型模具在使用过程中常见的质量重易腐蚀的问题,选择G48工程塑料为制造材料,对模具整体结构、制造工艺等方面进行改进,叙述了一种轻量化的耐腐蚀复合材料铺叠模的设计制造技术,使该类型模具轻量化且防锈蚀。     

锻压机床轻量化研究现状和发展趋势

阐述了锻压机床轻量化实施中存在的关键问题:刚度、强度和动态性能等约束条件的不确定性,液压机动态特性受液压系统影响大,可靠性基础数据的获得和实验存在一定难度,要综合考虑液压管路和电气线缆走线设计等.指出研究中可采用等寿命设计、智能优化算法、多目标优化、可靠性设计、应用新材料新结构等方法提高机床的整体性能,实现机床整体轻量化.提出将动态设计、快速设计、可靠性设计、多目标优化等融于锻压机床轻量化技术是发展趋势.     

斜床身卧式车床床身结构轻量化设计研究

文章根据多年来国内外科研工作者在结构设计上的研究成果,对机床支承件结构设计基本流程进行归纳和总结。并以DL32M斜床身式车床床身为研究对象,分别对床身的结构构型与特征尺寸进行优化设计,研究了斜床身卧式车床的床身结构轻量化设计方法,并形成了较为系统的斜床身卧式车床的床身结构轻量化设计方法,该方法对机床支承件结构优化设计具有参考价值和指导意义。     

基于仿真软件Working Model运动仿真系统的研究与开发

在机床的研制开发过程中,通过对机床三维建模和运动仿真,模拟机床的动态特性,并通过虚拟加工工件,不但能使设计和应用人员直观地看到机床的加工过程,可通过考察各铰链以及各部件的相对运动状态,检验支链是否发生干涉,从而可以交互式地进行机床结构参数的调整和改进,又可以检验零件数控加工程序和加工方法的正确性,为提高产品质量,降低成本,缩短产品投放市场的时间提供了非常有效的途径.     

大型结构件孔内键槽铣削专用机床研制

本文介绍了大型结构件孔内键槽的加工方法及专用铣削机床。该机床可用于大型结构件通孔键槽的铣削，特别是对锥孔、盲孔内键槽的加工更具有优越性。     

基于结构仿生的高速机床工作台轻量化设计

生物体具有性能优异、轻质高效的结构形式,体现了材料的最优化分布,为机械结构的轻量化设计提供了原型与方法。通过总结轻质高效生物体结构的构型规律,应用于高速机床工作台筋板的结构仿生设计。利用Ansys的APDL参数化语言建立优化模型,确定工作台筋板的最优结构参数。结果表明,通过布置环形夹层筋板以及最大变形梯度方向上对角筋的方法是有效的,并使结构比刚度效能提高11．29％,从而实现结构的仿生轻量化。     

Modeling the machining stability of a vertical milling machine under the influence of the preloaded linear guide

The prediction of machining stability is of great importance for the design of a machine tool capable of high-precision and high-speed machining. The machining performance is determined by the frequency characteristics of the machine tool structure and the dynamics of the cutting process, and can be expressed in terms of a stability lobe diagram. The aim of this study is to develop a finite element model to evaluate the dynamic characteristics and machining stability of a vertical milling system. Rolling interfaces with a contact stiffness defined by Hertz theory were used to couple the linear components and the machine structures in the finite element model. Using the model, the vibration mode that had a dominant influence on the dynamic stiffness and the machining stability was determined. The results of the finite element simulations reveal that linear guides with different preloads greatly affect the dynamic behavior and milling stability of the vertical column spindle head system. These results were validated by performing vibration and machining tests. We conclude that the proposed model can be used to accurately evaluate the dynamic performance of machine tool systems designed with various configurations and with different linear rolling components.     

重心驱动原理在高速卧式镗铣加工中心关键部件结构设计中的应用

介绍了重心驱动技术的原理,针对高速卧式镗铣加工中心的结构特点,提出了将重心驱动技术应用在主轴箱、滑架等关键部件结构设计的方法.利用有限元分析软件对应用“重心驱动技术的高速卧式镗铣加工中心整机进行了动静态特性分析,得到了其应力、应变图及前四阶固有频率和振型图.分析结果表明采用“重心驱动”的加工中心具有良好的动静态特性,因此重心驱动技术作为一种新型的数控机床进给驱动方式,可以有效地减少加工中心的振动,提高其动静态特性.     

An adaptronic approach to active vibration control of machine tools with parallel kinematics

In recent years, more and more lightweight components are used in machine tools in order to provide advantages in highly dynamic applications because of their reduced mass. One major drawback of these lightweight systems is their sensitivity to structural vibrations which are induced by high jerks during fast positioning and the machining process itself. Moreover, in case of parallel kinematic structures, the dynamic response depends nonlinearly on the actual pose of the mechanism in the workspace. In this paper, a concept for active vibration control for a machine tool with planar parallel kinematics is presented. For this purpose, an adaptronic rod has been developed and integrated into the existing machine tool. The unit consists of a high-power lead–zirconate–titanate piezo stack actuator, which is able to induce forces in longitudinal direction of the rod, and various sensors so that different control concepts from the field of active vibration control can be implemented and tested. Based on a flexible multibody system model of the machine tool, a hierarchical controller consisting of an integrated force feedback as low authority Control combined with a frequency-shaped linear quadratic regulator has been designed. The experimental results presented here demonstrate the ability of the chosen approach to clearly suppress the first dominating resonance without loss of performance in the low frequency range, which is often a serious problem of active damping concepts.     

石墨高速加工机床的发展现状

总结了石墨高速加工机床的特点,详细介绍了目前常用的国外石墨高速加工机床的主要机型及其基本性能,为石墨高速加工机床选型提供依据.     

High speed servo control of multi-axis machine tools

Advances in high-speed machining technology, including those in spindle speeds and cutters, are out-pacing advances in the servo control performance of machine tools. To close this gap, new machine tools and improved controls must be developed. Improvements to machine tools under development include special-purpose machine tools, the use of advanced materials, the replacement of ball screws and ways with linear motors and roller guides, and the use of parallel link actuators. This paper focuses on the control issues that will become increasingly important as these high-speed machining and high-speed machine tool advances are realized.The main issues in high-speed servo control are feed rate planning, and servo loop control laws. A method is developed in this paper which takes advantage of the full performance envelope of each axis in an arbitrary path. This near-complete usage of the servo capabilities of a machine tool results in reduced cycle time or reduced path error. A servo loop control law is then developed that uses the axis performance envelope as well as instantaneous position, velocity, and acceleration information of the target path and machine axis to improve servo performance in the presence of disturbances.     

Development of a high-speed 3-axis machine tool using a novel parallel-kinematics X-Y table

In this paper we discuss the development and performance evaluation of a high-speed, 3-axis milling machine using a novel parallel kinematics x-y table. The x-y table is based on a an inversion of the Oldham coupling. The advantages of this kinematic configuration include low inertia, uniform kinematic conditioning, and dynamically matched axes. The design of the x-y table makes this system particularly well suited for high-speed contouring in the x-y plane. The kinematics, dynamics, and mechanical design of the system are described. Linear and circular contouring experiments are conducted to evaluate the system capabilities. The stiffness of both the mechanism as well as the direct drive actuation system are measured and reported. The experimental results demonstrate that the proposed mechanism offers an attractive combination of performance characteristics for high-speed contouring and high-speed machining.     

自动夹紧刀具行星增速延长附件铣头结构

介绍一种高转速大扭矩的行星增速延长附件铣头结构。在不改变机床主轴转速的情况下,采用行星增速单元实现延长附件铣头增速的目的,满足了重型龙门镗铣加工中心高转速大扭矩的加工要求,提高了机床的加工精度和加工效率。该结构结构紧凑、布局合理、装配方便。     

电火花成型电极的高速切削加工

现代机械切削加工中,高速切削（High Speed Cutting）是一重要的发展方向,已开始被广泛使用。以高速、高精度和大进给为主要特征的高速切削加工近几年来发展十分迅速。本文通过高速切削机床加工一个手机型腔模石墨电极的过程,介绍和探讨高速加工在电火花成型方面的应用。     

提高轮廓加工误差联机检测精度的研究

在数控机床或加工中心上采用联机检测轮廓加工误差的方法，不用价格昂贵的坐标测量机，具有简单、省时、经济的特点。文章分析了数控机床或加工中心的直线运动误差对联机检测轮廓加工误差精度的影响，并测量出了加工中心的几何运动误差，提出了消除机床几何运动误差影响，提高轮廓加工误差联机检测精度的方法。实验结果表明，所采用的方法可以明显提高轮廓加工误差联机检测精度。