粉料除铁机电磁系统及结构设计

应用电磁理论和振动机械理论，针对玻璃、冶金、铸造、陶瓷等行业普遍使用的除铁机，设计了电磁系统及结构。主要部件的结构尺寸为：激磁线圈，采用双玻璃丝包扁铝线，截面积为19mm^2共600匝，轭铁尺寸为δ=110mm，每根弹簧刚度为41．25kg／cm，两台JW08B-4-M2型0．18kW激振电机。     

振动电磁除铁器基本设计参数的选取

振动电磁除铁器能快速、高效、低耗地除去粉状耐火材料、玻璃原料、电瓷物料中的铁磁物质，并且操作简便。本文从振动电磁除铁的原理出发，导出了除铁器的振幅、生产率及振体空间在励磁回路中所需的磁感应强度等基本设计参数。     

基于数学模型的摩擦焊接用电磁振动头动态特性研究

设计了一种新型结构的振动摩擦焊接用电磁振动头,通过变分原理和拉格朗日方程建立该新型电磁振动头的数学模型,利用该数学模型在Simulink中仿真研究该新型电磁振动头的动态特性。仿真结果表明:在电压一定时,振幅在系统谐振点附近显著增加;在不同频率的电流下,在系统谐振点附近的振幅亦可满足摩擦焊接过程的实际需要。仿真结果与实验结果相符,验证了该新型电磁振动头的实际工程应用价值。     

再生铝合金除铁述评

综述了再生铝合金中铁的主要来源及其对性能的危害性,概述了目前再生铝合金除铁的常见方法,即重力沉降法、离心去除法、过滤法、电磁分离法和熔剂法,指出了除铁对扩大再生铝原料的应用和提高再生铝产品品质的重要意义,及适合再生铝生产的除铁熔剂广阔应用前景。     

再生铝合金除铁述评

综述了再生铝合金中铁的主要来源及其对性能的危害性,概述了目前再生铝合金除铁的常见疗法,即重力沉降法、离心去除法、过滤法、电磁分离法和熔剂法,指出了除铁对扩大再生铝原料的应用和提高再生铝产品品质的重要意义,及适合再生铝生产除铁熔剂的广阔应用前景.     

再生铝合金除铁述评

综述了再生铝合金中铁的主要来源及其对性能的危害性,概述了目前再生铝合金除铁的常见方法,即重力沉降法、离心去除法、过滤法、电磁分离法和熔剂法,指出了除铁对扩大再生铝原料的应用和提高再生铝产品品质的重要意义,及适合再生铝生产除铁熔剂的广阔应用前景。     

锰合金电磁搅拌成型过程振动影响分析

在分析电磁搅拌成型原理的基础上,开展了锰合金成型过程中振动特性的实验研究,从电流和频率两个衡量振动强度指标方面分析了振动对成型质量的影响。结果表明,电磁搅拌技术对改善锰合金的微观组织及减少裂纹条数有重要的意义;开裂温度与频率呈反比例关系,为锰合金成型过程中电磁搅拌参数的选择提供了依据。     

圆盘式电磁振动上料器CAD系统研究

以圆盘式电磁振动上料器为对象，对ＣＡＤ在振动上料器产品设计中的应用进行了研究，并初步开发出一个ＣＡＤ系统，本文对该系统的组成，功能设置及其实验作了详细描述。     

电磁振动上料机

我厂于1981年5月研制了一台电磁振动螺旋上料机,用于砂轮平面磨床提升钢砂,经过试验,证明达到了设计要求。这台电磁振动螺旋上料机基本参数如下:提升高度990毫米,功率:300×2=600W,振动频率:3000次/分钟,最大振幅:1.5毫米,螺旋槽直径:240毫米,螺旋槽螺距:30毫米,钢砂提升能力:5公斤/分钟。     

高速电主轴电磁振动噪声多场耦合分析

为了研究电主轴电磁场特性对主轴振动及噪声的影响。通过有限元分析法,计算了电主轴电机的瞬态电磁场,并对电主轴电磁振动及噪声进行了响应分析;同时对正常运行的电主轴进行噪声实验,提取出主要的电磁噪声信号,经过分析处理后与仿真结果进行对比。结果表明,当电磁力波与定子铁芯二阶固有频率接近时,产生的电磁振动是最大的;且当电主轴在24000r/min转速下稳态运行时,电磁力产生最大噪声声压值的频率为13800Hz。通过实验与仿真的相结合,验证了电主轴电磁振动噪声多场耦合分析的结果是相对真实可靠的。     

基于LabVIEW的数字滤波技术处理平衡去重机的振动信号

平衡去重机是教学实验、工程测试中的重要设备.本文针对平衡去重机中振动信号的数字滤波问题,引入了LabVIEW软件平台.通过软件的方法设计了相关滤波器,实现了对振动信号的数字滤波,有效地提高了精度和工作效率.     

Dynamic analysis of a motor-integrated method for a higher milling stability

The productivity in High Speed Cutting is often limited by undesirable vibration effects in the main spindle (chatter). In many cases these limits are far below the technically possible cutting parameters provided by the machine technology. This paper presents a new approach to a motor-integrated milling spindle with an embedded electromagnetic actuator to actively reduce chatter vibrations and increase productivity. It is based on the non-contact application of highly-dynamic damping forces on the spindle shaft. That way the process stability can be increased significantly. By measurement and simulation-based analysis of spindle dynamics and transient and analytical approaches to process stability, the efficiency of the damping method is demonstrated in theory. Finally, a new, soft magnetic composite based motor-integrated electromagnetic actuator is introduced in this article.     

On-line control of machine tool vibration in turning

This paper presents a system developed for on-line vibration control on a turning lathe. Relative vibration between the workpiece and the cutting tool is sensed with the help of a bifurcated bunch of optical fibres which is then phase shifted, amplified and fed back to a specially designed piezoelectric vibrator supporting the tool. Whenever a vibration occurs, leading the machine tool-cutting process system to instability, the close-dloop feedback contour, with the help of the vibrator-exciter, generates an equal and opposite force to stabilize the vibration. Results obtained by mathematical modelling and experimental investigations indicate a significant improvement in the dynamic characteristics of the machine tool resulting in considerably higher productivity, accuracy and finish.     

球铁管表面喷锌机的设计与研究

球铁管是我国“九五”和“十五”期间大力推广和发展的项目 ,在大量的设计和应用基础上 ,对球铁管生产使用的重要设备之一———表面喷锌机进行了系统的研究与分析 ,提出了相关的设计思想和方法。对于提高表面喷锌机的使用性能和生产效率具有重要意义     

高效板坯连铸结晶器技术

为了实现唐钢1700板坯连铸机尽快减少漏钢生产事故,达产达效,主要从优化结晶器铜板及镀层材质,优化结晶器内钢水的流场和温度场,优化结晶器振动系统等方面开展工作,最终在质量改善的前提下,实现了拉速由1.6m/min提高到1.9m/min,机时产量提高达18%。     

Machine ensemble approach for simultaneous detection of transient and gradual abnormalities in end milling using multisensor fusion

In a fully automated manufacturing environment, instant detection of the cutting tool condition is essential for the improved productivity and cost effectiveness. This paper studies a tool condition monitoring system (TCM) via machine learning (ML) and machine ensemble (ME) approach to investigate the effectiveness of multisensor fusion technique when machining 4340 steel with multilayer coated and multiflute carbide end mill cutter. In this study, 135 different features are extracted from multiple sensor signals of force, vibration, acoustic emission and spindle power in the time and frequency domain by using data acquisition and signal processing module. Then, a correlation-based feature selection technique (CFS) evaluates the significance of these features along with machining parameters collected from machining experiments. Next, an optimal feature subset is computed for various assorted combinations of sensors. Finally, machine ensemble methods based on majority voting and stacked generalization are studied for the selected features to classify not only flank wear but also breakage and chipping. It has been found in this paper that the stacked generalization ensemble can ensure the highest accuracy in tool condition monitoring. In addition, it has been shown that the support vector machine (SVM) outperforms other ML algorithms in most cases tested.     

基于机床进给伺服系统中频振动抑制研究

伺服系统以其高性能、高精度等优势被广泛应用于数控机床和机器人上。机床进给伺服系统中由于滚珠丝杠等传动装置刚度有限,柔性连接方式易引发振动而影响其稳定性与精度。针对旋转进给伺服系统中存在的中频振动,提出一种基于二阶状态观测器的速度扰动观测补偿中频振动抑制方法,由速度观测器观测出的速度与实际速度反馈相减,通过带通滤波提取振动信号,作为补偿给到速度反馈上,抵消系统振动,提高系统带宽并保持稳定性和精度。最后在不同的速度环增益下,通过仿真和实验验证了所提方法的有效性。     

Grain refinement of primary Si in continuously cast hypereutectic Al–Si alloy by electromagnetic vibration

Abstract

Refinement of Si crystals in hypereutectic Al–20 wt-%Si alloys was carried out using low frequency electromagnetic vibration direct chill casting of billets with 100 mm diameter. Low frequency electromagnetic vibration was produced in the liquid metal by the simultaneous application of a stationary magnetic field and a variable magnetic field. The stationary magnetic field was generated by supplying an induction coil with direct current. The variable magnetic field was created by another induction coil below the top of the mould, which is supplied with an alternating current. The effects of low frequency and addition of chromium and/or iron were tested. The frequency <37 Hz promoted inhomogeneous distribution of primary Si due to heavy stirring. The diameter of primary Si applied with 27 Hz was ～19 μm. Cr addition, even on the strong magnetic stirring of 15 Hz, shows refinement and homogeneous distribution of primary Si.     

Development of a new rotary ultrasonic spindle for precision ultrasonically assisted grinding

In our previous work, a new method for inducing a machine spindle to ultrasonically vibrate was proposed in which the axial ultrasonic vibration is excited by a fluctuating electromagnetic force applied to the spindle. The validity of this method was also confirmed experimentally. In this paper, focusing on the development of a new rotary ultrasonic spindle based on this new method, an actual ultrasonic spindle unit was designed and constructed in accordance with the previous work. The unit consists of an ultrasonic spindle, two rotary bearings and their housings for holding the spindle, eight electromagnets and their supporters for the generation of a fluctuating electromagnetic force, and a base plate. Its performance was also investigated experimentally for different exciting conditions. The results showed that an ultrasonic vibration with a sub-μm order amplitude is generated on the produced spindle and that the applied electromagnetic force affects the spindle performance significantly.