加工活塞的电磁式微机给机构及其功率优化

异圆活塞的高速车削加工需要高响应，低发热的刀具微进机机构。原机械消耗功率过大，发热严重，并且需要小型化，本文提出了一种交直流励磁分离的功率优化措施可以有效地解决上述问题。     

加工活塞的电磁式微进给机构及其功率优化

异圆活塞的高速车削加工需要高响应，低发热的刀具微进给机构。原机构消耗功率过大，发热严重，并且需要小型化，本文提出一种交直流励磁分离的功率优化措施可以有效地解决上述问题。     

动态链接库技术及其在信号分析中的应用

介绍了VC 6.0中动态链接库的三种基本编程方法,并分析其优缺点.以一个实际的信号分析方法-相干函数的编制为例,阐述了DLL编程的基本流程和技术,此方法已经成功地应用于实际项目,取得了良好效果.     

人工免疫算法及其在塑性加工中的应用

人工免疫系统是模拟自然免疫系统信息处理功能的一种智能方法,具有学习、自组织、记忆等进化学习机制。文章介绍了生物免疫系统信息处理机理;论述了多种人工免疫模型及一般的免疫算法结构和克隆免疫算法,并讨论了免疫算法与其他技术的融合;综述了现在各种人工免疫系统在工程方面的应用;对人工免疫系统在塑性加工领域的应用进行了展望与探讨。     

PCBN刀具及其在切削加工中的应用

PCBN(聚晶立方氮化硼)刀具具有硬度高、韧性好、热稳定性好和化学惰性大等特点，并可用金刚石砂轮开刃修磨，在切削加工的各个方面都表现出了优异的切削性能，特别适合加工各种淬硬钢、冷硬铸铁等难加工材料。     

微细电火花加工技术在组合加工中的应用

概述并分析了微细电火花加工技术的发展现状及遇到的问题.介绍了微细电火花加工技术与其他微细加工技术相互组合,完成微小零件制造的各种工艺方法.     

虚拟制造技术及其在塑性加工中的应用

随着计算机技术和信息技术的发展 ,虚拟制造技术在传统加工制造业中得到广泛应用。采用虚拟制造技术可以缩短产品开发周期、降低成本、提高产品质量 ,从而提高产品的市场竞争力。本文阐述了虚拟制造的基本概念 ,并通过实例介绍了虚拟制造技术在塑性加工中的应用。     

高进给铣刀及其在高效粗铣加工中的应用

在诸多铣削加工新技术中，用高进给铣刀进行粗铣加工是一项在缩短加工工时方面极具潜力、但目前尚未引起广泛注意和充分重视的技术。高进给铣削的加工经济性引人注目，通常可使加工效率提高50％或更高，可使加工工时缩短几小时、几天甚至几周。     

数控电火花线切割加工在塑料模加工中的应用

分析了数控电火花线切割加工在塑料模加工中的应用场合,探讨了数控电火花线切割加工在塑料模加工应用中的几种特殊方法.     

ALE有限元方法在金属塑性加工中的应用

ALE (ArbitraryLagrangian Eulerian)有限元方法中 ,网格划分是在参考构形中进行的 ,网格独立于物体和空间运动 ,可以根据需要自由选取。因此 ,ALE有限元避免了La grangian有限元中的网格畸变 ,又克服了Eulerian有限元中难以描述自由边界的不足。对ALE有限元用于分析塑性加工过程进行了探讨 ,并利用Galerkin方法 ,推导了离散形式的求解方程。最后的数值算例验证了该算法的有效性。     

Tracking control and active disturbance rejection with application to noncircular machining

Control systems are usually required to track reference signals while operating under the influence of disturbances. A fast tool servo system for noncircular machining application works under such conditions, resulting in large control efforts. This paper presents a linear active disturbance rejection controller design for a voice coil motor-driven fast tool servo system for noncircular machining application. The controller is designed through an extended state observer to estimate and compensate the variant dynamics of the system, nonlinearly variable cutting load, and other uncertainties. Then, a simple proportional derivative controller produces the control law. To improve the tracking performance of the fast tool servo, the tracking error from the trial-cutting workpiece is added to the reference input and used as feed-forward error compensation. In such a combined control arrangement, the active disturbance rejection controller provides active disturbance rejection ability for the controller, and the feed-forward error compensation controller improves the tracking precision. Both the tracking control and disturbance rejection performances are thus enhanced. In real-time control and implementation, the effects of finite word length, position feedback resolution, and short sampling period are analyzed and addressed. Machining experiments are conducted, and the results illustrate the control system synthesis procedures and a substantial improvement over the tracking error generated by the linear active disturbance rejection controller alone.     

The application of high-speed CNC machining to prototype production

This paper describes the application of high-speed milling to the production of monolithic, metallic, functional prototypes, with special emphasis placed on the applicable process times. An example component is selected and the relevant process times are presented. Fundamental requirements for the use of high-speed milling to produce prototypes in a timely manner are identified. These requirements include: 1) high speed/high power spindles, 2) proper spindle speed selection based on the system dynamics, 3) machining parameter definition based on tool wear, 4) high feed/high acceleration machine drives, 5) intelligent path generation, and 6) pre-process verification of arbitrary three-dimensional CNC part paths. The implementation of the Simultaneous Trilateration Laser Ball Bar (STLBB) system to measure the CNC part paths is described and the device verification procedure is outlined. Example two and three-dimensional path measurements are also shown.     

电机电流的检测及其在模糊智能加工系统中的应用

分析了进给电机电流与相应的切削分力之间关系,用最小二乘法建立了它们之间的数学模型,以进给电机电流为监测切削负载的手段,实现了基于模糊芯片的铣削过程的模糊控制。     

Improving machining performance of wire electrochemical discharge machining by adding SiC abrasive to electrolyte

The use of wire electrochemical discharge machining (WECDM) to slice hard brittle materials has recently been studied because its effectiveness is independent of the mechanical characteristics of the machined materials. Therefore, materials with high hardness, brittleness, strength and electrical insulation, which are difficult-to-cut, can be machined. In ECDM, the electrochemical reaction produces hydrogen bubbles, which accumulate around the cathode. A thin gas layer forms on the surface of the electrode and isolates the electrode from the electrolyte. When a voltage that exceeds the critical voltage is applied, continuous discharge occurs. The material near the electrode is removed by the discharge erosion and chemical etching. The use of WECDM to cut electrically insulating materials has only recently been investigated. However, the breakdown of the gas in the bubbles and the vibration of the wire in WECDM strongly affect the shape accuracy. This work aims to improve the over cut quality by adding SiC abrasive to the electrolyte. A mechanism that combines discharge, chemical etching and abrasive cutting is studied. The effects on expansion, roughness and material removal rate (MRR) are discussed. The experimental results reveal that adding abrasive reduces the slit expansion because it increases the critical voltage. The particles disrupt the bubble accumulation to form an isolating layer around the wire, increasing the critical voltage and reducing the discharge energy. The surface roughness is improved because the abrasive helps to refine the micro-cracks and melted zone that is formed by discharge heat erosion. Meanwhile, smaller grit produces lower roughness. The quality of the slit can be controlled; its expansion and roughness of the slit are 0.024 mm and 0.84 um Ra, respectively.     

Compound machining of titanium alloy by super high speed EDM milling and arc machining

A novel compound machining of titanium alloy (Ti6Al4V) by super high speed electrical discharge machining (EDM) milling and arc machining was proposed in this paper. The power supply consisted of a pulse generator and a DC power source which were isolated from each other. A rotating pipe graphite electrode was connected to the negative pole of the power supply. The plasma channel was able to deionize, and maximum material removal rate (MRR) reached 21,494 mm³/min with a relative electrode wear ratio (REWR) of 1.7% because of high current and efficient flushing. Compared with traditional EDM, the compound machining achieved a significantly higher MRR but a similar REWR. To investigate the characteristics of the compound machining, the effects of electrode polarity, peak voltage, peak current, and flushing pressure on the performance of the process, including its MRR, REWR, and radius of overcut (ROC), were determined. In addition, scanning electron microscopy, X-ray diffraction, and microhardness analysis were conducted. Result shows that the proposed method can machine difficult-to-machine materials efficiently.     

数控加工过程建模和仿真的研究与应用

介绍了数控加工系统(数控机床)模型建立的理论,然后根据这种建模理论给出一个在数控加工仿真平台VERICUT上实现的适用于任何加工系统的通用建模方法和步骤,最后运用此方法对具体的数控加工过程进行建模、仿真和优化.     

High-precision machining by measurement and compensation of motion error

This paper describes a systematic method to model and compensate geometric errors of machine tools. In order to separate geometric errors from other errors, measured errors are analyzed in the frequency domain by using the Fourier series. Then, the frequency components corresponding to geometric errors are selected based on the repeatability of their wavelength. Finally, the components are reconstructed and forwarded for the compensation by a fine motion drive. A CNC machine tool with a fine motion mechanism on the Z-axis was developed to compensate the error components in the Z direction on the XY plane. A flat surface machining with non-rotational cutting tools was tested to validate our approach. On the plane of 45 mm×70 mm, the fluctuation of the relative displacement was reduced from 1.3 to 0.5 μm P-V. Machining experiments with a single-crystal diamond tool were also carried out and the straightness of the profile curve was reduced from 1.0 to 0.4 μm. The result of the experiments showed that the geometric errors were compensated separately from the vibration due to the bending mode of the machine column.     

A review of machine-tool vibration and its influence upon surface generation in ultra-precision machining

Vibration in ultra-precision machining (UPM) is an intrinsic physical phenomenon, which is a key factor influencing surface generation. With a focus on passive vibration, this paper reviews the latest research into vibration characteristics and the effect of vibration on surface generation in UPM. The opportunities and challenges facing researchers are also discussed and suggestions are made for future related studies. It is found that active vibration can possibly be employed to improve surface quality influenced by passive vibration in UPM.     

大型龙门式五轴加工中心仿真系统在UGNX7．5上的建立和应用

对数控编程计算机碰撞仿真加工系统进行分析和研究。通过在UGNX7．5中进行二次开发,研究了在UGNX7．5中开发五轴数控机床切削仿真加工环境,并以T35龙门五轴联动加工中心为例,详细介绍了在UGNX7．5中对大型龙门结构的数控五轴加工中心机床的切削仿真加工系统进行开发的方法与过程,开发了T35在UGNX7．5中的碰撞仿真加工系统。T35机床的仿真系统,对在其上加工的复杂零件刀具路径及机床运动可以进行精确的模拟加工,真实地反映和再现实际的加工过程,大大减少了机床的试切时间,提高了CAM程序的安全性和可靠性,降低了产品研发的成本。