先进光学磨削中杯形修整技术开发及应用

对于金刚石砂轮修整,尤其是有高精度要求的圆弧金刚石砂轮,杯形砂轮修整技术可以获得较好的砂轮磨削性能以及修整效率。本文开发了配套超精密平面磨床使用的杯形修整器,分析了其机械误差影响,并完成了修整实验及砂轮表面测量及半径拟合处理,从宏观上考察了该修整器对砂轮磨削性能的提高,结果证明该修整器可以进行有效修整,提高了加工工具精度,能满足金刚石砂轮修整使用要求。     

渐开线螺旋齿轮成形磨削砂轮的修整

针对渐开线螺旋齿轮磨削加工要求,对磨削螺旋齿轮的砂轮进行研究。基于螺旋面形成的基本思路,得出直母线作螺旋运动形成的渐开螺旋面方程,建立了渐开线螺旋齿轮的数学模型。提出了通过MATLAB软件编程计算磨削砂轮轴向截形的方法。根据截形数据,提出了通过CNC砂轮修整器修整砂轮的方法,对砂轮进行数控修型。用修整好的砂轮对渐开线螺旋齿轮进行数控成形磨削加工。计算结果表明磨削法与其他方法相比可显著提高螺旋齿轮的齿形精度和表面质量,提高磨削效率。     

CNC复杂型面修整及恒线速磨削方法研究

介绍了使用砂轮进行复杂型面特别是硬齿面磨削的特点。分析了砂轮磨损较快的原因。研究了复杂型面磨削的修整方法和恒线速磨削的原理。详细介绍了CNC砂轮修整器在磨床中的应用及其伺服控制系统的设计。研究结果表明,采用CNC砂轮修整器不仅可以完成复杂型面磨削及修整,而且实现了恒线速磨削的功能,提高了工件的表面质量和磨削效率,同时也完善了磨床的功能,提高了磨床的品质。     

汽车变速器齿轮高精度磨齿机床研究

面向汽车变速器行业对高精度齿轮的需求,开发一种蜗杆和成型砂轮复合磨削的双工件主轴磨齿机床。该机床具备全自动更换刀具和全自动装卸被加工齿轮功能,可使用通用修整器同时修整蜗杆砂轮和成形砂轮;采用双工件主轴结构,节省了上下料装载时间,加工效率大幅提升,比单主轴效率高出30%左右;在合适的粗磨和精磨砂轮颗粒的作用下,蜗杆砂轮和成形砂轮磨削的结合使磨削时间减少了50%左右;自带齿轮检测设备,能够在线检测齿轮磨削加工量是否达到加工工艺要求,实现了齿轮磨削高效、高精度、节能环保加工。     

异型螺杆数控磨床的研制及相关技术的研究

在分析螺杆成形磨削所需基本运动基础上，提出了用三根伺服控制轴实现螺杆磨削和成形砂轮修整的螺杆磨床基本结构。通过双圆弧样条进行螺杆型线离散点的曲线拟合，由与砂轮轴线相垂直的离散截面求取砂轮的截形，回避了利用瞬时接触线方程求解方法的困难，并讨论了在零度砂轮安装角情况下求取成形砂轮截形的条件。螺杆磨削计算控制专用软件模块具有砂轮截形计算和修整轨迹自动计算以及NC程序自动生成的功能。     

恒速磨削的实现方法与机床设计

针对复杂型面传动件磨削质量多变的状况,以工件的外圆磨削为例分析磨削过程中磨削速度变化的原因,提出一种新的磨床结构,利用CNC砂轮修整器和伺服数控系统完善了磨床的功能。该磨床既可以快速准确地完成复杂型面传动件磨削所用砂轮的修型,也可以实现恒速磨削,从而提高工件的磨削质量和磨削效率。     

陶瓷结合剂金刚石砂轮的修整研究(Ⅰ)——各种修整方法的修整效果比较

金刚石砂轮欲获得满意的磨削效果必须进行适当的修整。目前一些常用的金刚石砂轮修整方法中,单点式金刚石修整笔和聚晶金刚石修整笔有较高的修整效率,但所修金刚石砂轮的磨削性能难以令人满意,SEM观察表明,此时砂轮表面的磨粒顶端大都被修平。制动式修整器所修金刚石砂轮的磨削性能好,但砂轮的不圆度仍有2～3μm,为了改进修整效果,本文提出了一种使用GC杯形砂轮的修整方法和装置。实验证明,此方法在修整效果和效率方面效果良好。     

一种固定式砂轮修整器的设计与分析

砂轮修整器是磨床使用中的关键部件,其结构要求在满足修整砂轮要求的同时,还应考虑到金刚滚轮的更换以及修整器通用性、功能性的提升。综合考虑修整器的结构和使用过程,设计一种固定式的、既安装金刚滚轮又安装成型滚轮的修整器,在增强其功能性的同时,充分考虑到滚轮的更换问题,提出了合理的方案。     

精密螺纹磨削砂轮修整技术分析及应用

针对螺纹磨床砂轮修整的特点,介绍了螺纹磨床砂轮修整方法和修整工具的应用,分析了数控砂轮修整器的设计思路和结构特点。重点分析和比较了钢滚轮和金刚石滚轮应用的技术特点,详细介绍了螺纹型面数学模型的建立、计算方法以及滚轮在修整砂轮中的应用和技术,解决了精密螺纹磨削砂轮的成型修整难题。     

基于人机界面的高精度数控内圆磨床控制系统设计

针对汽车液压挺杆类零件内孔的高精度磨削要求,确定出高精度数控内圆磨床工作参数,并提出机床控制系统及其软件设计方案.在机床控制系统设计中,对工件径向进给(X轴)及砂轮修整进给的控制,采用PLC主机-定位单元控制伺服驱动器和伺服电动机的控制方案,对砂轮(Z轴)轴向往返运动的控制,采用液压驱动砂轮快进快退、往复电机驱动往复磨削的控制方案.在人机界面和PLC控制软件设计中,针对该机床的五种工作方式及控制功能要求,完成了界面友好、操作方便、功能完善的合理软件结构,达到了预期的控制目的.     

D杯形砂轮修整碟形金刚石砂轮试验研究

本文采用了D杯形砂轮与碟形砂轮对磨法来修整大直径树脂结合剂碟形金刚石砂轮。在分析研究杯形砂轮修整碟形砂轮的修整原理及修整方式的基础上，用自行研制的专用修整装置，从主轴转速、修整深度、修整工具结合剂类型等方面进行了对比工艺试验研究，总结了杯形砂轮修整碟形砂轮的不同工艺参数与修整效率、修整质量之间的工艺规律。试验结果表明，在本试验条件下主轴转速500r／min，修整深度0．02mm的修整效率较好；细粒度、中等浓度的青铜结合剂杯形金刚石砂轮与粗粒度、高浓度的杯形砂轮修整碟形砂轮相比，后者具有较好的修形效果和修整效率；D杯形砂轮与GC杯形砂轮交替配合使用可以大大提高碟形金刚石砂轮的修形效率和修锐效果。     

An experimental investigation of dry-electrical discharge assisted truing and dressing of metal bonded diamond wheel

Metal-bonded diamond wheels have superior qualities such as high bond strength, long wheel life, wear-resistant ability and high grinding efficiency. But it is very difficult to true and dress diamond wheel because of its highest hardness. Traditional mechanical truing does not guarantee truing accuracy of diamond wheel because of single diamond dresser wears out very quickly. To reduce wear of diamond dresser and hence guarantee a desired wheel surface, a novel truing and dressing method, namely, dry electrical discharge (dry-ECD) assisted truing and dressing, is proposed and tested to achieve good dressing quality and efficiency. Because the diamond wheel is mounted on the MK9025 optical profile grinder, dielectric liquid is forbidden. The new dry-ECD dressing/truing method basically eliminates the use of dielectric liquid. Therefore, it is free from the serious problem of electrolytic corrosion caused by electrolytic current flowing through water encountered in conventional ECD. The FE analysis of temperature distribution in dry-ECD assisted truing and dressing diamond wheel using ANSYS is performed in this study. Temperature field simulation helps to select optimized parameters under certain conditions. Energy dispersive X-ray (EDAX) analysis was used to measure the composition of diamond wheel before and after dry-ECD assisted truing and dressing. Further, hard alloy grinding experimental results proves that a little variation in material composition of diamond wheel after dry-ECD assisted truing and dressing does not influence grinding result. A series of experiments of dry-ECD assisted truing and dressing of metal bonded diamond wheel are conducted to investigate truing efficiency, truing accuracy, dresser wear, dressed wheel profiles and three-dimensional truing/dressing forces in comparison with those of the conventional single diamond methods. Experimental results show that the new dry-ECD assisted truing and dressing technique offers a number of advantages over the conventional single-tip diamond dressing and truing method. Furthermore, mechanism of the dry-ECD assisted truing and dressing is investigated through the careful analysis of the properties of chips.     

基于小波包分解与支持向量机的金刚笔钝化识别研究

金刚笔修整器的钝化导致所修整砂轮廓形恶化,对磨削质量产生严重影响.本文研究了基于声发射的金刚笔钝化识别,利用小波包分解频带能量提取特征量,通过支持向量机(SVM)进行钝化的分类识别.试验结果表明,与常用的人工神经网络相比,该方法在小样本的情况下也具有良好的识别效果,适合于实际应用.     

Production of multifluted drills on six-axis CNC tool-grinding machine

This paper presents a kinematic model to produce multifluted drills on a six-axis CNC tool-grinding machine. There are three special features of the proposed model. The first is the use of Denavit-Hartenberg notation to establish the ability matrix of a six-axis CNC tool-grinding machine. The second feature, the concept of a virtual hollow grinding wheel and virtual solid dresser, is invented to allow flutes and flanks to be machined by a single grinding wheel in one setup, thus improving manufacturing precision and lowering production costs. Thirdly, we present configuration matrices to express grinding wheel positions and orientations during machining of flutes and flanks. NC data equations are obtained by equating corresponding elements of the ability matrix and the configuration matrices of the grinding wheel. To verify the proposed methodology, a designed three-fluted drill was machined on a six-axis CNC tool-grinding machine. This paper combines the activities of drill design and manufacturing, making the production process more flexible, automatic, cost efficient and controllable.     

Rotary dressing model for grinding wheel active surface prediction

A kinematic model of rotary dressing of corundum grinding wheels is presented. Based on wheel and dresser specifications and process kinematics, effects of rotary dressing parametres on wheel topography are predicted. For model validation, wheel surface is characterized by areal roughness parametres, obtaining a deviation less than 15%. Besides, influence of wheel topography on ground part surface quality is investigated. Results highlight the significance of modelling the dressing process and show the model translates into a useful tool for selection of most suitable dressing parametres for achieving specific surface qualities. Moreover, it eases the way to predicting dressing originated defects.     

A novel laser-assisted truing and dressing technique for vitrified CBN wheels

The preparation of vitrified CBN or diamond wheels by truing and dressing has a large influence on the grinding performance. A worn diamond dresser cannot produce sufficient protrusion of cutting grain edges. To reduce the wear of diamond dressers and hence guarantee a desired wheel surface, a novel truing and dressing method, namely, laser-assisted truing and dressing, is proposed and tested to achieve good dressing quality and efficiency. A systematical experimental feasibility study on this newly proposed laser-assisted truing and dressing technique is conducted by investigating truing efficiency, truing accuracy, dresser wear, dressed wheel profiles, and specific forces in comparison with those of the conventional single diamond methods. Experimental results show that the new laser-assisted truing and dressing technique offers a number of advantages over the conventional single-tip diamond dressing and truing method. In addition, the underlying mechanism of the laser truing and dressing process is investigated through the careful analysis of the properties of chips and the microscopic structural characteristics of wheels.     

In-process evaluation of grit protrusion feature for fine diamond grinding wheel by means of electro-contact discharge dressing

This paper introduces a new in-process evaluation method for grit protrusion feature on wheel surface by monitoring discharge current trace during electro-contact discharge (ECD) dressing of metal-bonded fine diamond grinding wheel. First an impulse discharge machining experiment was carried out to investigate the correlation between metal bond removal and discharge parameters, namely discharge current I_e and discharge pulse duration τ_e. Then ECD dressing experiment for #600 diamond grinding wheel was conduced to analyses the quantitative effect of the discharge parameters (I_e and τ_e), derived from discharge current trace between wheel and dresser (electrode), on grit protrusion feature of wheel surface. The result shows that the grit protrusion feature is sensitive to the discharge parameters (I_e and τ_e) with reference to mean diamond grit size d_gm. Further, the discharge parameters (I_e and τ_e) in ECD dressing should conform to the discharge variables’ requirement of , by which the grit protrusion feature may be evaluated and the dressing process variables may be determined. Finally, the in-process evaluation method was successfully applied to ECD dressing of #1500 diamond grinding wheel for valid grinding of hard-brittle materials.     

旋转金刚石修整工具修整超硬磨料砂轮的研究

本文对比研究了金刚石修整笔和旋转金刚石修整工具,在修整超硬磨料砂轮时修整力、工具磨损、修整效率等参数的变化规律,结果表明:超硬磨料砂轮的修整中,旋转金刚石修整工具修整力、修磨效率和磨损等几乎不随修整次数增加发生变化,其原因是修整工作是由整个圆周上金刚石分担,旋转型金刚石修整工具在修整过程中,具有挤压砂轮的作用,使被修整的金刚石砂轮表面具有较好锋利度.结果表明:在优化的修整工艺条件下,旋转金刚石工具可以实现对超硬磨料砂轮的精密修整.     

Profiled rotary dresser with controlled size and distribution of abrasive grits: Performance assessment

This paper reports on a novel proprietary profiled rotary dresser which, in contrast with conventional tools, enables a controlled arrangement of geometrically defined abrasives over complex profiles. Output forces and abrasives’ wear were investigated during dressing and grinding tests. This showed a significant reduction in radial dressing forces (˜37%) and volumetric loss of material per grit (˜21%) when compared with conventional tools, together with low grinding forces and workpiece surface roughness variability for different wear conditions. The novel dresser proves the ability to obtain uniform wear rates along complex profiles, while allowing abrasive segment replacement to restore the dressing conditions.     

高效磨削用超硬磨料砂轮钎焊技术研究现状与发展

超硬磨料钎焊砂轮是实现高效磨削的重要工具。与传统的砂轮相比,钎焊砂轮不仅提升了自身的结合强度,还具有容屑空间大、不易堵塞、磨料利用充分等显著优势。为提高高效磨削用超硬磨料钎焊砂轮的整体性能,综述国内外研究者在超硬磨料钎焊砂轮活性钎料的研制、砂轮地貌及其优化、钎焊工艺方法研究、新型钎焊砂轮的结构设计和钎焊砂轮的精度问题等方面的研究工作。超硬磨料钎焊砂轮精度和成本问题是制约超硬磨料钎焊砂轮在高效磨削中应用发展的瓶颈。研究并解决超硬磨料钎焊砂轮的精度和制造成本的问题,对于促进高效磨削技术的发展具有重要意义。