表面磨削温度的测定

将夹层热电偶法用于测量磨削温度,用这种方法测定表面磨削温度要比用砂轮—工件热电偶法优越,因为用它在测定不同材质工件的表面磨削温度时无需另作定标。为了考虑热电偶结点的热惯性影响,设计了一种模拟砂轮作用的恒热源,从而可以确定热电偶的热惯性特性。本文将磨削温度的试验值与着重从考虑磨削比能而推导计算出的理论值进行了对比。最后对测试结果及该测温方法的效用进行了讨论。     

移动测量架装置设计

在使用传统的方法磨削多档外圆时,往往会选取测量尺寸公差比较高的一档进行测量、其它的尺寸档采用定程磨削的方法。针对在采用定程磨削时的工作状况,分析了造成尺寸精度下降的原因。根据采用手工调整测量装置会耗费大量的人力和时间,且对现场操作人员要求较高的实际情况,介绍了一种移动测量架装置的设计。结果表明,新设计的移动测量架装置与传统测量架相比,可实现自动在线测量工件的多档尺寸,提高了工作效率。在今后的磨床设计中具有借鉴作用。     

网络通讯技术在磨削质量监控中的应用

研究并开发了一套新型红外线磨削温度自动检测系统.该系统将中央磨削质量检测室中的计算机和全厂的关键磨床组成局域网,可以实时监测每一台磨床的磨削温度.磨床的磨削温度由自行研制的红外线磨削温度自动检测仪来测量.当磨床的磨削温度超过计算机限定值时,中央磨削质量检测室的工程师可通过局域网将磨削用量、修整砂轮和切削液冷却强度等信息显示在磨床的液晶屏上,以供磨床的操作者参考并采取相应措施来降低磨床的磨削温度,可以实现零件在限定的磨削温度范围内高质量、高效率加工.本系统目前已应用在磨削现场,其中磨削温度测量准确,局域网传递信息精确,方便了工程师对现场操作人员的指导,极大地提高了磨削工作效率.     

磨削温度的试验研究

经过试验和理论计算,研究了磨削区的最高磨削温度。详细探讨了热电偶测温技术的实质和过程。利用热电偶测量了磨削接触区的最高温度。对测量温度值与理论计算值进行了比较,试验结果与采用磨削热模型理论的计算结果基本一致。     

高速磨削电主轴冷却系统的试验研究

高速磨削电主轴的温升对电主轴的加工精度和使用寿命有着重要的影响。以SPM170高速磨削电主轴为研究对象,采用理论分析和试验验证的方法对高速磨削电主轴的冷却系统进行了研究。通过分析可知电主轴电机部分的产热主要是由铁芯损耗产生的,水冷系统可以有效地带走电机部分的热量,使电主轴的温升降低。对SPM170高速磨削电主轴的冷却系统进行了改进,设计了一种新型螺旋水道,在电主轴最高工作转速时,分别测量电主轴前轴承壳体温度,并对比其温升。结果表明:采用改进之后的螺旋水冷装置电主轴的温升比改进前温升降低了10℃左右,温升得到了有效的控制。     

高效深切磨削温度的研究

指出了高效深切磨削技术的最新发展。并对高效深磨中的磨削温度的计算模型,计算方法,测量技术做了研究。对高效深磨中磨削温度的最新研究成果给予了描叙。最后对今后的研究给予了展望。     

平面磨削中工件温度场的直接测温

平面磨削中工件温度场采用红外成像的电荷偶合装置(CCD)测量。在高空问、瞬时条件下红外辐射(IR)温度测量一直是沿磨削试件一侧进行测定试件表面和次表面的温度。用斜面磨削的方法，使磨削深度持续增加，获得了随材料磨除率而改变的磨削温度的变化。这些测量结果与用传统的恒磨除率磨削试验具有良好的相关性。确定了最高温度的位置和值，包括温度梯度。讨论了确定磨削热模型测量的含意及工件的烧伤苗头的预测。     

脆性材料平面磨削温度场的测量及分析

磨削温度直接影响砂轮寿命、加工成本和工件质量,一直是磨削加工领域研究加工过程及其本质的重点.获得磨削弧区温度及工件实际的温度场分布是研究磨削热机理的基础.本文采用NEC TH31-110红外热像仪,测量了平面干磨削脆性材料时的热像图,获得了工件整体温度场分布及沿层深的温度分布数据,确定了工件磨削接触区的最高温度及其准确...     

静电喷涂涂层砂轮磨削钛合金工件温度研究

针对钛合金材料难磨削加工的特点,设计了一种静电喷涂砂轮涂层系统和实验砂轮,完成了干式磨削钛合金的实验,分析了不同磨削条件对磨削温度的影响规律。研究表明:采用静电喷涂固体润滑剂涂层砂轮磨削加工钛合金,在同样的加工条件下,磨削深度为0.2 mm时,未涂层砂轮磨削温度接近900℃,涂层砂轮磨削温度不超过600℃。固体粉末静电喷涂润滑砂轮涂层可有效降低磨削温度。      

龙门测量架装置设计

在使用传统的方法磨削多档外圆时,往往会选取测量尺寸公差比较高的一档进行测量,其他的尺寸档采用定程磨削的方法。针对采用以上方法可能会造成尺寸精度下降的问题,在分析了实现测量各档不同轴颈的不同方法之后,设计了一套龙门测量架装置,进行了设计方案的比较。结果表明,新设计的龙门测量架装置与传统测量架相比,可实现实时自动测量工件的多档外径,在今后的磨床设计中具有借鉴作用。     

Development and Application of a Wheel Based Process Monitoring System in Grinding

As an advantage to conventional monitoring systems sensor equipped grinding wheels offer the possibility to gain information on the process status from direct measurements of physical quantities in the contact zone. This can be realized by the integration of small temperature and force sensors into segmented grinding wheels. A new thermocouple sensor concept was developed whose novelty is the continuous contacting of the thermocouple by the grinding wheel wear. Further tests where conducted using a piezoelectric sensor integrated into the grinding wheel. By this set-up, forces in grinding as well as in dressing processes were obtained. After assessing the system's capability for monitoring grinding and dressing processes tests in an industrial environment showed the reliability of the monitoring system which therefore may become the basis for a novel kind of process control in the future.     

基于PC机和80C196单片机的温度微机控制系统

文章介绍了由PC机和80C196单片机构成的热处理温度微机控制系统,并就集中温度数据采集方法、PC机和单片机的数据通信格式、单片机软硬件设计、双向晶闸管的触发电路等相关技术进行了分析,给出了串行通信中断接收及数据处理程序设计流程图.     

Virtual high performance grinding with CBN wheels

The development of future products requires designing, manufacturing, and testing components in a virtual environment before hardware parts are actually made. This paper presents a generalized process simulation and multi-constraint optimization strategy for five-axis grinding with cubic boron nitride (CBN) wheels to increase material removal rates while avoiding process problems such as damage to the machined surfaces and premature wheel failure. The wheel-workpiece engagement conditions under five-axis grinding are extracted from a CAM system by geometrically processing the NC program, the wheel geometry and the part geometry. The interpreted geometric contact data are used in combination with empirical grinding models to predict physical process parameters such as forces, power, heat flux, and temperature. These parameters are then used as the decision variables in a multi-constraint optimization to optimize process parameters such as workspeed to reduce cycle time.     

Fast time constant estimation for plunge grinding process control

The time constant of a grinding control system indicates the speed of response to a control command and reflects variations of the wheel condition. In order to allow correct and continuous control adjustment, fast in-process estimation of the parameter is necessary. The significance of the grinding system time constant is discussed and the control system for the plunge grinding process described. An algorithm for fast time constant estimation is presented for adaptive control of the grinding process. The algorithm is useful for geometry-based grinding control systems where a workpiece size sensor is used and multiple control tasks are implemented. Experimental testing of the algorithm is explained and comparison between results from grinding and those from analysis shows that the proposed algorithm is sufficiently accurate and effective for adaptive control of the plunge grinding process.     

磨削过程在线监测系统

为了适应小批量、多品种磨削过程的在线监测的要求，本文采用声发射（AE）传感器和功率传感器联合监测磨削过程。通过采用声发射信号归原处理法，可实现对磨削条件多变环境下砂轮钝化进行有效监测，利用该方法可以克服仅靠监测AE信号幅值变化不能监测工作材料，加工要求和磨削参数经常变化环境下砂轮钝化程度的缺陷，同时利用功率传感器对砂轮破碎进行监测，针对磨削条件复杂，难以建立数学模型的难点，本文采用神经网络建立传感器信号与监测信号的非线性关系。     

在线示教式弧焊跟踪控制系统的研究

针对微动开关式弧焊跟踪传感器在现有应用上存在的不足，本文提出了一种新颖的焊缝偏差延时记忆控制方法。文中介绍了弧焊跟踪主／从式单片机控制系统的硬件及软件设计，并对系统的跟踪调节作用过程进行理论分析。试验研究表明，该系统工作可靠，控制方案正确，适用于较大曲率焊缝的跟踪，有实际应用价值。     

基于自动检测与机械手的全自动锯片磨削数控系统

文章详细介绍了在数控锯片磨削加工系统中,采用毛坯供给机械手和电感式位移传感器,实现对毛坯上下料,毛坯与成品尺寸检测以及锯片磨削加工等磨削全过程的自动控制方法.其特点在于将磨削过程、毛坯供给与检测三个过程独立开采,使得本文开发的全自动锯片磨削系统,实现在锯片磨削加工同时,一边用机械手来上下料和锯片尺寸的检测,不仅提高了自动化水平,而且有效地重叠了磨削加工时间和毛坯准备时间,显著提高了生产效率.     

外圆磨削颤振监测方法设计

磨削颤振是影响加工质量和加工效率的重要因素,常需增加多个后续加工周期来满足加工质量的要求。采用涡流传感器、磨削力传感器、声发射传感器、加速度传感器和接触探头等多传感器对砂轮边沿的自激振荡进行测量,对自激振荡信号,提出采用幅值法和小波分析法进行分析处理,实现了磨削颤振的自动监测和预测,减少了加工周期,提高了加工效率。     

Numerical analysis of grinding temperature measurement by the foil/workpiece thermocouple method

High temperatures generated in grinding are the main factor responsible for thermal damage on the ground surface. The energy partition ratio is often investigated experimentally in order to predict this temperature. The method of the foil/workpiece thermocouple is frequently used. The disruptions of this measurement technique have been studied numerically on a global scale of the wheel by a 2D finite element method taking into account the mica sheets and the constantan foil. The longitudinal thermal inertia of the thermocouple has been determined for various junction thicknesses. The simulations show that the systematic error on the maximum temperature rise (MTR) measurement cannot be neglected and is dependent on grinding conditions such as the workpiece velocity and the arc contact length. Moreover, the junction thickness and the assumed heat flux conducted into the electrode also have an influence on this error. However, the sensor is always accurate during the cooling time outside the foil/wheel contact zone. Consequently, the assessment of the partition ratio is more reliable when made during the cooling phase rather than through the MTR.     

An analysis of grinding power and surface roughness in external cylindrical grinding of hardened SCM440 steel using the response surface method

The aim of this study was to analyze effectively the grinding power spent during the process and the surface roughness of the ground workpiece in the external cylindrical grinding of hardened SCM440 steel using the response surface method. A Hall effect sensor was used for measuring the grinding power of the spindle driving motor. The surface roughness was also measured and evaluated according to the change of the grinding conditions. Response surface models were developed to predict the grinding power and the surface roughness using the experimental results. From adding simply material removal rate to the contour plot of these mathematical models, it was seen that useful grinding conditions for industrial application could be easily determined.