三维曲面数控磨削砂轮磨损测控与补偿研究

针对三维曲面数控磨削 ,设计测量仪 ,其和数控磨削系统相配合 ,完成砂轮磨损的测量和补偿 ,提高了三维曲面磨削精度及砂轮耐用度 ,并应用于电视机尾锥玻壳模具的磨削     

砂轮磨损状态的声发射检测及其误差补偿方法的研究

砂轮磨损会破坏砂轮型面,对加工精度有重要影响。利用声发射方法检测砂轮的磨损状态以及修整过程,并提出了实现砂轮磨损误差在线补偿的方法。     

大型数控机床导轨直线度误差测量与实时补偿

以试切工件的方式研究大型数控机床导轨的直线度误差。用安捷伦激光干涉仪分别测量机床和工件的导轨直线度误差,提出一种混合建模方法。并针对FANUC CNC系统的外部坐标原点偏移功能研制了一种直线度误差实时补偿器。结果表明:通过补偿,直线度误差减少60%以上。不过为保证补偿方案的有效性,机床后续的补偿加工行程需要与误差建模行程一致。     

基于在线检测技术的砂轮磨损补偿方法研究

在硬质零件数控磨削加工中,砂轮磨损的补偿技术是常见的难点技术之一。本文研究了一种利用在线检测技术对砂轮磨损进行补偿的方法。     

基于共路光线漂移补偿的直线度测量

针对影响激光测量直线度误差的主要因素之一激光光线漂移,提出了一种基于共路光线漂移补偿的直线度误差测量方法,给出了具体的测量原理和系统构成。从产生激光光线漂移的几个因素出发,理论分析了所产生的光线漂移对直线度误差测量的影响,建立了相对应的光线漂移补偿模型。结果表明,进行补偿后激光器出射光线引起的光线漂移在X方向的最大漂移量由28.4μm减少为5.6μm,Y方向的最大漂移量由21.6μm减少到5μm;由温度梯度引起的光线漂移经补偿后最大漂移量由65.7μm减少为8.9μm。实验结果与理论分析均表明,该方法能有效减少各种因素引起的光线漂移对直线度测量结果的影响,提高测量直线度误差的准确性。     

精密机械三维误差测量与补偿

机床的工作台移动误差可分为直线位移误差与空间误差，机床的直线位移误差是与轴线方向相同的定位误差，一般形成的原因包括丝杠的节距误差与线性编码器误差。空间误差则是在空间中无需与各轴运动方向相同的定位误差。这些误差一般为空间向量，其组成包含上述的直线位移误差(Linear displacement error)、垂直直线     

螺旋面成形磨削误差补偿砂轮截形研究

在螺旋面成形磨削加工中,存在着由机械加工和安装工艺带来的系统误差,这些误差将直接影响成形磨削精度。提出了一种将系统误差作为恒定误差,并反馈到砂轮截形算法中,通过改变砂轮理论截形方程来消除误差的思想。研究了基于误差补偿的螺旋面成形磨削砂轮截形算法,并利用Visual C++开发出了一套通用性强,操作简便的螺旋面成形磨削砂轮修整软件系统。实验结果表明:磨齿精度达到6级以上。     

面齿轮蜗杆砂轮的成形修整工艺误差建模及补偿方法

蜗杆砂轮磨削是面齿轮的精加工工艺,蜗杆砂轮修整精度直接影响面齿轮磨削精度。本文分析了修整工艺误差对磨削齿面误差的影响规律,并提出了一种面齿轮蜗杆砂轮的成形修整工艺误差建模及补偿方法。首先,建立面齿轮蜗杆砂轮的数学模型,分析面齿轮蜗杆砂轮的成形修整原理,提出利用圆柱齿轮磨齿机的多轴耦合联动实现面齿轮蜗杆砂轮的成形修整。其次,将修整工艺误差分为轴向位置和径向位置误差,分析轴向位置和径向位置误差对磨削齿面误差的影响规律,提出成形修整工艺误差的补偿方法。最后,进行蜗杆砂轮补偿修整、面齿轮磨削加工及测量实验,实验表明：左齿面齿形误差由补偿前51.9μm到补偿后7.9μm,右齿面齿形误差由补偿前35.3μm到补偿后17.6μm,验证了误差补偿方法的有效性。     

标准节流装置非设计工况的全补偿

标准节流装置非设计工况的全补偿＊钟继贵（东南大学动力系南京２１００１８）１引言标准节流装置按额定参数设计,因此对测量蒸汽和气体流量而言,当被测流体参数变化时,即流体的温度、压力和流量偏离节流装置的设计点时,流量公式中的流出系数、膨胀系数、流体密度等参...     

Automatic compensation for grinding wheel wear by pressure based in-process measurement in wet grinding

This paper deals with an application to automatic compensation of grinding wheel wear by a pressure based in-process measurement method in wet grinding. A pressure sensor is set beside a grinding wheel with a small gap. When grinding fluid is dragged into the gap by the rotation, hydrodynamic pressure, which corresponds to the gap length and the topography, can be measured. No electromagnetic properties of the workpiece and grinding wheel affect measured results. This method is applied to a CNC surface grinding machine. The pressure distribution and the relationship between the pressure and the gap length are measured. The pressure is decreased with the increase of the gap length. Its dispersion is around 1% for 0.5 μm-wear of a grinding wheel with 250 μm grit size. The dimensional error of a workpiece using the feedback of the wear is less than the feeding step, for the compensation, of 1 μm.     

滚刀铲磨用砂轮零编程数控修整方法

提出一种滚刀铲磨用砂轮零编程数控修整方法,分析砂轮修整原理,得到砂轮修整数学模型.在此基础上,给出砂轮修整零编程数控系统总体构成及其控制流程,并在滚刀铲磨车床上进行实际应用.     

电主轴砂轮更换装置的创新设计

从分析现有大型砂轮机构装卸实际情况入手,简单介绍了电主轴的结构,重点论述了电主轴砂轮机构自动更换砂轮的实施过程.     

A grinding force model allowing for dulling of abrasive wheel cutting grains in plunge cylindrical grinding

A mathematical model is developed for the grinding force in cylindrical plunge grinding that allows for the grinding conditions, the size of the flank wear land areas formed on the grinding wheel cutting grains, the properties of the work material, and the geometrical parameters of the grinding tool and work surface. A formula is obtained for calculating the stock removal rate as a function of the degree of dulling (glazing) of the grinding wheel. The adequacy of the mathematical model of the grinding force in cylindrical plunge grinding is established.     

Form-truing error compensation of diamond grinding wheel in CNC envelope grinding of free-form surface

In computer numerical control (CNC) grinding of free-form surface, an ideal arc profile of trued diamond grinding wheel is generally employed to plan 3D tool paths, whereas its form-truing errors greatly influence the ground form accuracy. A form-truing error compensation approach is proposed by using an approached wheel arc profile to replace the previously designed ideal one. The objective is to directly compensate the trued wheel arc-profile errors. It may avoid the time consumption of traditional approach that compensates the measured coordinate point errors of workpiece to an iterative grinding operation. First, the 3D tool path surface was constructed to plan the 3D tool paths. Second, the CNC arc truing of grinding wheel was conducted to analyze the form-truing error distribution relative to the applied wheel arc profile. Then, the form-truing error compensation was carried out in CNC envelope grinding. Finally, the iterative closest point (ICP) algorithm was used to match the measured coordinate points of workpiece to ideal free-form surface. It is shown that the 3D tool path surface constructed is practicable to plan arbitrary 3D tool paths for the form-truing error compensation. The ICP matching may be used to investigate 3D ground form error distribution. It is confirmed that the form-truing error compensation can directly improve the 3D ground form accuracy. It may decrease the 3D ground form error by about 20% when the 2D form-truing error is reduced by about 58% using the same truing conditions for CNC grinding.     

圆柱齿轮偏心对成形磨齿精度的影响及补偿

为分析齿轮偏心对磨齿精度的影响并通过数控系统对偏心进行补偿、有效提升磨齿精度,基于机床工作空间和工件空间的几何关系建立了磨削误差的几何模型,进一步按照齿轮标准《ISO1328—1:1995》详细分析了齿轮偏心对齿廓、齿向及齿距误差的影响,以及在几何偏心情况下齿轮参数变化对各项误差的敏感性。基于数控成形磨齿机磨削原理提出了径向补偿、切向及径向综合补偿两种补偿措施,分别对两种补偿结果进行了分析。通过国产SKMC3000/20数控成形磨齿机对安装偏心进行试验验证,结果表明该方法可有效补偿因齿轮偏心造成的磨齿误差,进一步提高成形磨齿精度。     

轮毂柔性自动加工单元中的联动程序设计

设计了轮毂柔性自动加工单元的联动程序,参考了工艺和工序的要求,并充分考虑到多工件时候容易产生的多动作时序需求,以及在程序中依据传感器检测和逻辑控制要求,达到向单元中其他部分发送命令和监控的要求。整个加工单元经受住了300h不间断无故障运行的考验,现已经进入可以实际生产销售的阶段。     

In-process force measurement for diameter control in precision cylindrical grinding

This article shows the theory and implementation of a force measurement-based approach to controlling workpiece diameter in cylindrical grinding. A simple model proposed is used to relate infeed velocity to grinding force. The model is extended to accurately control the amount of material removed in outer diameter plunge grinding given the normal force, which may be monitored in real-time. The model incorporates the key parameters, including the structural loop stiffness, the plunge infeed velocity, and the wheel and workpiece properties. However, only the infeed velocity must be explicitly known. The contribution of this work is experimental validation that the lag between infeed and stock removal can be predicted using force feedback without a priori knowledge of the grinding system. This allows very accurate diameter control (0.25 μm of nominal), even in the presence of thermal drift, wheel wear, and machine error.     

钢轨CBN砂轮高速打磨试验台设计与试验研究

研制一种可模拟高速打磨实际工况的高速CBN砂轮打磨试验平台、该试验台可模拟砂轮纵向、垂向进给,并且可以实现±50°偏转,实现钢轨的正向、侧向的打磨。通过试验台模拟打磨试验验证了CBN砂轮高速打磨钢轨的可行性,并得出3#复合结合剂砂轮最适合高速打磨,最优打磨砂轮线速度70m/s^80m/s,最优下压力800N^1000N。     

In-process measurement of surface roughness during cylindrical grinding process

An in-process surface roughness sensor developed by the author has been applied to cylindrical grinding operations. The sensor utilizes fibre optics to illuminate a workpiece surfacec and to detect the intensity of the reflected light. A change of surface roughness during one plunge grinding cycle is measured for various grinding conditions. It is confirmed by the measurements that the surface roughness is closely related to changes of the workpiece radius during a grinding cycle. The result is quite simple and it is useful in determining the cycle time of a grinding operation.