超硬砂轮修整的研究——制动式整形器的理论与实践

超硬砂轮修整的困难,是生产上推广应用的主要障碍之一。本文对制动式整形器进行了理论上的分析,并进行了实验。找出了影响整形效率和整形精度的规律,提出了制动式整形器合理使用的方法和适合的参数。整形器价格低廉,可直接在生产上使用,是一种有效的整形工具。     

THE EFFECT OF THE CBN WHEEL DRESSING AND THE GRAIN HEIGHT PROTRUDING FROM THE BOND ON THE GRINDING PERFORMANCE

CBN (Cubic Boron Nitride) is a highly efficient abrasive and has unique properties (highhardness, high thermal stability and high chemical inertia). As early as 1969 CBN Wheels had al-ready been made and showed excellent performance for grainding high speed steels and othermaterials hard to be ground. So far, however, CBN Wheels are still not popularly utilized in theindustry, the writer considers the main reason being the inadequate study for practical applica-tions and especially the suitable dressing technique. The dressing of resinoid CBN Wheels discussed in the paper, is different from that ofconventional ones. It has to be divided into two operations, truing and sharpening, each of whichhas its specific and independent functions. A simple dressing method with a lot of informationsuitable for production is studied; finally, the grain height protruding from the bond is taken asan index for evaluating the dressing results, and the effect of grain height on the grinding per-formance is discussed. By selecting proper conditions according to the workpiece requirements, abetter technical and economical benifit can be obtained.     

CBN刀具切削低碳钢的研究

CBN刀具切削淬硬钢,已有很多资料作了报导,但切削未淬硬的低碳钢却无研究,本文对此进行了探讨,且着重研究了CBN刀具切削未淬硬低碳钢的磨损形态和机理,从而证实了CBN刀具切削低碳钢是不适宜的。     

用立方氮化硼砂轮磨削超硬高速钢

用刚玉砂轮磨削超硬高速钢,困难重重;而用立方氮化硼砂轮,则能顺利地进行磨削。与刚玉砂轮相比,立方氮化硼砂轮磨削超硬高速钢时,磨削力、磨削温度均较小,并能改善磨削条件,但表面粗糙度略高,这可从立方氮化硼磨料的优异性能予以解释。实验证实,用立方氮化硼砂轮磨削超硬高速钢是适宜的。     

修整力的分析与研究

本文系统地研究了修整参数(修整切深a_d、修整进给量f_d、修整速度V_d)、修整工具的磨损和冷却液对法向修整力F_(nd)变化的影响规律。用回归正交试验法,建立了法向修整力与修整参数之间的经验公式: 计算值与实测值相近,证明公式可靠。实验证明,法向修整力随着金刚石磨损而增加;冷却液对修整力影响不大。     

金刚石滚轮修整对磨削温度和烧伤的影响

应用金刚石滚轮成形修整砂轮,在大量生产中显示了极大的优越性。但使用不当,易使工件发生磨削烧伤,影响零件的使用寿命。本文分析研究了金刚石滚轮修整参数和砂轮特性对磨削烧伤的影响,并对合理使用国产金刚石滚轮提出了建议,可供机械制造厂和砂轮厂参考。     

评价砂轮硬度的新方法

砂轮硬度是直接影响磨削效果的一个重要因素,因而对于砂轮硬度的测定方法研究颇多。作者从砂轮定义出发,对目前广泛使用的四种测定砂轮硬度的方法作了评论,认为现行的测定方法,属静态测量,与实际情况不符,测定的数据不能准确反映砂轮的真实硬度。为了克服现行方法的局限性,在理论分析的基础上.提出了以修整力作为评价砂轮硬度的新方法,它具有动态测量的特性,更接近砂轮硬度的定义,更接近磨削的实际情况。实验结果和理论分析吻合,显示了优越性。     

使用双滚轮无心夹具时的磨削精度

本文对大批量内圆磨削生产中使用较多的两种夹具(电磁无心夹具和双滚轮无心夹具)进行了对比分析,并对使用双滚轮无心夹具后的内圆磨削精度进行了理论分析,提出了一些改进措施,对实际应用具有一定的指导意义。     

外圆切入磨削时的一些基本关系

本文对外圆切入磨削时的一些机理进行了实验研究。研究的内容是:第一,磨削过程对磨削结果的影响;第二,砂轮的修整条件和修整工具——单颗粒金刚石和板式多颗粒金刚石——对磨削表面粗糙度的影响;第三,修整工具的磨损及其对磨削结果的影响。在实验的基础上,从理论与实践两方面进行了分析,从工件、砂轮、修整工具、磨削过程诸方面来研究外圆切入磨削时的一些基本关系,有的规律不仅适用于外圆切入磨削,而且也适用于其它磨削。     

STUDY FOR INCREASING ACCURACY OF INTERNAL CYLINDRICAL GRINDING

Internal cylindrical grinding is much more difficult than other grindings, because of its lowproductivity and poor quality, e. g. taper often occurs in hole after grinding, which has an effect onthe service life of the workpiece. It is a pity that internal cylindrical grinding is rarely studied. Inthis paper. aimed at the above conditions, factors affecting the accuracy of internal cylindricalgrinding are theoretically analyzed. The roller shell of the ring spinning frame(as mass part)aretaken as an example, of which internal cylindrical grinding tests are made. Tests show that thetheory conforms with practice.