中国机床市场近期需求一瞥

汽车行业:加工箱体类零件的加工中心、加工回转体零件的数控车床和车削中心、数控高速滚齿机、数控蜗杆砂轮磨齿机、曲轴磨床、曲轴车拉机床、凸轮轴磨床、活塞车床等。机械基础件及机床工具行业:各类加工中心、数控车床数控大平面砂轮磨齿机、数控坐标磨床、数控导轨磨床、数控内圆磨床、精密小孔珩磨机、数控万能工具铣床、数控蜗杆砂轮磨齿     

切点跟踪数控曲轴磨床的研究与开发

采用切点跟踪磨削技术研制高速、高效和高精度的数控磨床,已成为曲轴磨削加工总体技术发展的趋势.对切点跟踪数控磨床设计的关键结构部件进行研究与开发,基于西门子840D数控系统对数控曲轴磨床加工控制软件的开发进行研究.     

以新技术一流产品和服务满足市场

近年来,中国汽车工业的崛起,为中国的经济增长增添了一大亮点,也为装备制造业的快速发展提供了机遇。上机公司为汽车及其零部件行业提供的配套装备以数控曲轴磨床为主。从1996年开始,在加大科研投入的同时,以用户的特殊要求作为新技术的突破口,全面提升数控曲轴磨床技术,近年来,为一汽、二汽、上海通用、奇端、柳州通用等汽车厂家提供了50台数控曲轴磨床。汽车零部件加工行业也是数控曲轴磨床的主要提供对象,如山东某曲轴厂拥有上机的数控曲轴磨床达40多台。汽车零部件行业,对上机提供的曲轴磨床、凸轮轴磨床普遍反映良好,尤其是凸轮轴磨床…     

数控曲轴磨床设计及双电动机同步驱动技术的研究

数控曲轴专用磨床是适应国内外磨削技术与工艺发展的要求而开发的一种高档数控磨床,主要用于中小型内燃机、汽车、摩托车中的曲轴偏心轴颈的高效磨削。在数控曲轴磨床中,双电动机同步驱动技术是数控曲轴磨床中的核心技术,对同步控制技术进行分析,经过应用证明控制效果良好,达到了数控曲轴磨床的精度要求。     

磨床行业市场情况

磨床是金切行业的一个重要分支。随着工业的发展，对机械零件的加工精度及表面粗糙度的要求日益提高，磨削加工显得更加重要。尤其在汽车、电力、船舶、冶金、军工、航空航天等行业，国产数控磨床正在发挥着越来越大的作用。“十一五”期间，经过调整和整合期后的磨床行业将会迎来新一轮的发展期。“十五”期间主要开发的产品有：数控外圆磨床（含端面外圆磨）、数控凸轮轴磨床、数控曲轴磨床、数控轧辊磨床、数控齿轮磨床、数控双端磨床、数控平面磨床、数控无心磨床及大量的各类专用磨床。从市场的结构来看，进口磨床的数额依然居高不下，不得不承认这是同我们的产品底气不足有很大的关系。     

高精度数控曲轴磨床的控制方案

讨论了数控曲轴磨床以主轴颈定位,以主轴颈中心为回转中心,一次装夹完成曲轴的主轴颈和连杆颈的磨削加工,克服了传统曲轴磨削加工中存在的缺陷.     

桑塔纳轿车发动机曲轴磨削加工生产线的开发研究

曲轴磨削加工生产线的建立旨在展示国产数控曲轴磨床在汽车发动机曲轴生产中的应用.该线的加工对象为桑塔纳轿车和桑塔纳2000型轿车汽车发动机曲轴,年加工量为3万根.     

SIEMENS 840D双通道功能和扭矩控制在曲轴磨床中的应用

介绍了SIEMENS 840D扭矩控制功能在曲轴磨床中的运用;阐述了SIEMENS 840D数控系统双通道功能和扭矩控制的原理;针对双通道控制PLC程序的处理,详细地介绍了数控双通道的参数设定和程序控制过程。通过SIEMENS 840D系统扭矩控制方法,优化了曲轴磨床的控制方法;经过应用后达到了边磨削边进行修整砂轮的目的,节省了加工时间并提高了工效。     

MK82125/H大型数控曲轴磨床

介绍了一种一次装夹即可加工中、高速船用曲轴的大型数控曲轴磨床,其性能可以满足船用曲轴精密磨削的需求.     

CBN高速数控外圆磨床的开发与应用

介绍了利用CBN砂轮进行高速磨削的特点与优势，对磨削状态下的头架负荷进行计算，并对CBN高速数控外圆磨床与非CBN磨床进行了技术性能及经济性分析和对比。介绍了两种CBN高速数控外圆磨床的规格、性能、结构特点以及在曲轴止推面加工中的应用。     

非惯性系柔性平面连杆机构系统完全动力学问题的回转键合图法

介绍了非惯性系柔性机械系统完全动力学问题的回转键合图法,给出了非惯性系下综合考虑刚、弹性及多种能域相互耦合的柔性机械系统键合图模型的建立方法。基于回转键合图理论,推导出便于计算机自动生成的系统状态方程及运动副约束反力方程的统一公式,有效地克服了微分因果关系及非线性结型结构给在计算机上自动建立系统状态方程及运动副约束反力方程所带来的十分困难的代数问题。所述方法特别适合于多能域并存的系统。结合实例来说明本文方法的有效性及通用性。     

锅炉压力容器计算机辅助焊接工艺评定系统

随着计算机被引入焊接工艺评定领域 ,国内外均对此开展了研究工作[1～ 7] ,并开发出多个这方面的软件 ,但现有软件存在功能单一、实用性差、可信任度不够和开发工具落后等缺点[8] ,本文依据ＪＢ442 0和ＪＢ470 8两个标准采用可视化开发工具ＶＢ6 0开发了锅炉压力容器计算机辅助焊接工艺评定系统 (ＣＡＷＰＱＳ)。　　 1　系统模型按照国内外的标准 ,并非所有的焊接工艺都必须经过焊接工艺评定试验验证合格 ,只要存在依照标准可以证明拟定工艺可直接用于生产的焊接工艺评定报告 ,拟定工艺可不必进行评定而直接用于生产。这样可充分利用数据…     

Dynamic analysis of harmonically excited non-linear structure system using harmonic balance method

An analytical method is presented for evaluation of the steady state periodic behavior of nonlinear structural systems. This method is based on the substructure synthesis formulation and a harmonic balance procedure, which is applied to the analysis of nonlinear responses. A complex nonlinear system is divided into substructures, of which equations are approximately transformed to modal coordinates including nonlinear term under the reasonable procedure. Then, the equations are synthesized into the overall system and the nonlinear solution for the system is obtained. Based on the harmonic balance method, the proposed procedure reduces the size of large degrees-of-freedom problem in the solving nonlinear equations. Feasibility and advantages of the proposed method are illustrated using the study of the nonlinear rotating machine system as a large mechanical structure system. Results obtained are reported to be an efficient approach with respect to nonlinear response prediction when compared with other conventional methods.     

伺服阀流量动态校正改善电液位置系统性能的理论和方法

电液位置伺服系统起动过程会造成系统压力突降和执行器运动速度大幅波动,产生液压冲击;当系统有多个执行器工作时,系统压力突降会导致其他执行器产生误动作,甚至发生安全事故。针对上述问题,提出两种解决方法。一是将位置控制过程分解为速度和位置两个控制过程,且执行器的最大速度由系统最大流量和液体的压缩性限制。二是利用阀口压差对伺服阀流量进行修正。理论上阐述了两种方法的原理,采用数字仿真和试验进行了验证,结果表明,在不影响系统响应特性的前提下,两种方法可以消除电液位置伺服系统起动过程中的系统压力突降和产生的冲击。     

Identification of modal parameters of a time invariant linear system by continuous wavelet transformation

The applications of wavelet transforms have received significant attentions in many fields. This work proposes a procedure for identifying modal parameters of a linear system using the continuous wavelet transform. The merits of the proposed procedure over the exiting schemes of applying the wavelet transform to system identification for a linear system are in use of the time invariance property and filtering ability of the transform to enhance the efficiency of identifying the modal parameters of a structure from its earthquake responses or free vibration responses. The effectiveness and accuracy of the proposed procedure are validated via numerical simulations. The effects of noise and wavelet function on identifying the modal parameters of the structure are also explored in processing the numerically simulated acceleration responses of a six-story shear building subjected to base excitation. The dynamic characteristics of close modes are accurately determined. Finally, the proposed procedure is adopted to obtain the modal parameters of a three-story non-symmetric steel frame from its measured acceleration responses in a shaking table test. A total of nine modes are identified, including modes with high frequencies and very small amplitude.     

Dynamical analysis of transmission line cables. Part 2—damping estimation

In this work the authors try to establish a procedure to identify damping of transmission line cables in order to estimate in a simple (proportional) way the system damping matrix. The procedure is based on experimental and simulated data. The experimental data are collected through five accelerometers and the simulated data are obtained using the finite element method. To validate the mathematical model, the reduction of the system is used considering measured degrees-of-freedom. After that, the system damping matrix is estimated through different procedures.     

Precise position control of an electro-hydraulic servo system via robust linear approximation

This paper presents a study on electro-hydraulic servo system for the purpose of position control using a compatible linear model. The system has high level of nonlinearity and linearization introduces extra error in system model. In order to reduce this error several methods of linearization uncertainty are discussed. In spite of applying Taylor's series for all methods, several procedures are used for considering uncertainty on linearization constants. In the first procedure, a simple bound is considered for each linearization constant. In the second procedure, a polytope is extracted for the uncertainty by a graphical method. Finally, a procedure with less conservativeness and less restriction is proposed. This procedure is used to extract the linear model of the electro-hydraulic servo system for the task of position control. The resulting model is used to synthesize an output-feedback H_∞ controller for the EHSS using a Linear Matrix Inequality (LMI)-based approach. The effectiveness of the proposed method is demonstrated by simulation and experimental results. The results showed that the procedure is less conservative and has the fastest operation without any overshoot.     

制造联盟加盟支持系统的研究

提出基于Internet/Intranet的招投标制造伙伴选择方式，分析投标加盟决策内容和过程以及制造联盟加盟支持系统的功能需求，介绍制造联盟加盟支持系统的体系结构。简要论述系统中涉及的效益／风险评估、产品信息建模、制造资源能力评估、竞标工艺设计、成本估算与报价等关键技术。     

Dynamic modeling and validation of a tripod-based machine tool

In this paper, a reconfigurable tripod machine tool system is introduced, with a focus on dynamic modeling. The Newton-Euler approach is applied and a new modeling procedure is proposed. In the procedure of the dynamic modeling, the reference coordinate system for the forces/torques calculation and that for the equilibrium equations derivation are dealt with respectively. As a result, specific structural features of the tripod system are utilized to simplify the dynamic model and, thus, reduce the calculation complexity. The prototype tripod system is developed and the presented method is implemented for its configuration design. An experiment is conducted to validate the dynamic model.     

基于原型的渐进式工艺设计过程理论研究

研究工艺设计过程的概念、方法和模型的工艺设计过程理论，是ＣＡＰＰ的理论基础。它对ＣＡＰＰ体系结构、开发工具、过程优化以及智能型、并行和实用型ＣＡＰＰ系统的研究与开发有着重要的影响。本文通过对人类专家设计过程的分析，揭示出工艺设计过程的一些基本特征：渐进性、并发性和层次性。提出了基于原型的渐进式工艺设计过程理论，讨论了它的应用