外文翻译-- 数控机床精度的检测
数控机床精度的检测
摘要：随着制造业的快速发展，数控机床在机械制造业已得到广泛应用，且对数控机床的精度要求也越来越高。如何检测数控机床的精度，正成为各行业用户在验收与维护数控机床时非常关注的问题。
关键词：数控机床几何精度检测螺距误差补偿
现代数控机床集合了电子计算机、伺服系统、自动控制系统、精密测量系统及新型机构等先进技术，能够加工形状复杂、精密、小批量零件，并且具有加工精度高、生产效率高、适应性强等特点。随着制造业的快速发展，数控机床在机械制造业已得到广泛应用，且对数控机床的精度要求也越来越高。如何检测数控机床的精度，正成为各行业用户在验收与维护数控机床时非常关注的问题。
机床的精度主要包括机床的几何精度、机床的定位精度和机床的切削精度。现，就这些精度的检测项目、检测方法及注意事项进行综合的说明。
1 数控机床的几何精度
数控机床的几何精度反映机床的关键机械零部件（如床身、溜板、立柱、主轴箱等）的几何形状误差及其组装后的几何形状误差，包括工作台面的平面度、各坐标方向上移动的相互垂直度、工作台面X、Y坐标方向上移动的平行度、主轴孔的径向圆跳动、主轴轴向的窜动、主轴箱沿Z坐标轴心线方向移动时的主轴线平行度、主轴在Z轴坐标方向移动的直线度和主轴回转轴心线对工作台面的垂直度等。
常用检测工具有精密水平尺、精密方箱、千分表或测微表、直角仪、平尺、高精度主轴芯棒及千分表杆磁力座等。
1.1 检测方法：
数控机床的几何精度的检测方法与普通机床的类似，检测要求较普通机床的要高。
1.2 检测时的注意事项：
（1）检测时，机床的基座应已完全固化。（2）检测时要尽量减小检测工具与检测方法的误差。（3）应按照相关的国家标准，先接通机床电源对机床进行预热，并让
沿机床各坐标轴往复运动数次，使主轴以中速运行数分钟后再进行。（4）数控机床几何精度一般比普通机床高。普通机床用的检具、量具，往往因自身精度低，满足不了检测要求。且所用检测工具的精度等级要比被测的几何精度高一级。（5）几何精度必须在机床精调试后一次完成，不得调一项测一项，因为有些几何精度是相互联系与影响的。（6）对大型数控机床还应实施负荷试验，以检验机床是否达到设计承载能力；在负荷状态下各机构是否正常工作；机床的工作平稳性、准确性、可靠性是否达标。另外，在负荷试验前后，均应检验机床的几何精度。有关工作精度的试验应于负荷试验后完成。
2 数控机床的定位精度
数控机床的定位精度，是指所测机床运动部件在数控系统控制下运动时所能达到的位置精度。该精度与机床的几何精度一样，会对机床切削精度产生重要影响，特别会影响到孔隙加工时的孔距误差。
测量直线运动的检测工具有：标准长度刻线尺、成组块规、测微仪、光学读数显微镜及双频激光干涉仪等。标准长度测量以双频激光干涉仪的测量结果为准。回转运动检测工具有360齿精密分度的标准转台或角度多面体、高精度圆光栅和平行光管等。目前通用的检测仪为双频激光干涉仪。
2.1 检测方法（用双频激光干涉仪时）
（1）安装与调节双频激光干涉仪。
（2）预热激光仪，然后输入测量参数。
（3）在机床处于运动状态下对机床的定位精度进行测量。
（4）输出数据处理结果。
2.2 检测时的注意事项：
（1）仪器在使用前应精确校正。
（2）螺距误差补偿，应在机床几何精度调整结束后再进行，以减少几何精度对定位精度的影响。
（3）进行螺距误差补偿时应使用高精度的检测仪器（如激光干涉仪），以便先测量再补偿，补偿后还应再测量，并应按相应的分析标准（VDI3441、JIS6330）对测量数据进行分析，直到达到机床的定位精度要求。
（4）机床的螺距误差补偿方式包括线性轴补偿和旋转轴补偿这两种方式，可对
直线轴和旋转工作台的定位精度分别补偿。
3 切削精度
检查机床切削精度的检查，是在切削加工条件下对机床几何精度和定位精度的综合检查，包括单项加工精度检查和所加工的铸铁试样的精度检查（硬质合金刀具按标准切削用量切削）。检查项目一般包括：镗孔尺寸精度及表面粗糙度、镗孔的形状及孔距精度、端铣刀铣平面的精度、侧面铣刀铣侧面的直线精度、侧面铣刀铣侧面的圆度精度、旋转轴转900侧面铣刀铣削的直角精度、两轴联动精度等。
4 参考文献
1. Week, M.，机床手册．约翰威利& 桑司．纽约，1984.
2. 麻省理工学院工作底稿工业生产率委员会，麻省理工学院出版社, 坎布里奇, MA,1989.
3. 兰格, K., 金属成型手册，麦格劳·希尔, 纽约,1985.
4. 卡尔帕基安·S. ，机械制造，A^^ 版本，普伦蒂斯·霍尔，2000.
译文原文
On the accuracy of detection of CNC machine tools
Abstract With the rapid Development of manufacturing industry, CNC machine tools in the machinery manufacturing Industry has been widely used, and the accuracy of CNC machine tools are increasingly high requirements. How to detect the accuracy of CNC machine tools, various industries are becoming the user acceptance and maintenance of CNC machine tools much attention to problems.
Keywords CNC·geometric accuracy·Detection·Pitch error·compensation Modern CNC machine tool combines computer, servo systems, automatic control systems, precision measurement systems and new types of institutions of advanced Technology to processing of complex shape, precision, small-volume parts, and has the processing of high precision, high production efficiency, adaptability and so on. With the rapid Development of manufacturing industry, CNC machine tools in the machinery manufacturing Industry has been widely used, and the accuracy of CNC machine tools are increasingly high requirements. How to detect the accuracy of CNC machine tools, various industries are becoming the user acceptance and maintenance of CNC machine tools much attention to problems.
Accuracy of machine tools include the geometric accuracy of machine tools, machine tool positioning accuracy and precision cutting machine tools. On the basis of these precision of test items, test methods and precautions to conduct a comprehensive description.
1 A geometric accuracy of CNC machine tools
The geometric accuracy of CNC machine tools to reflect the key mechanical components (eg, bed, slide board, column, spindle boxes, etc.) the geometry of the error and its geometry after assembly errors, including the work surface flatness, each coordinate direction on the degree of perpendicular movement of the working table X, Y coordinates of the direction of movement parallel, radial runout spindle bore, spindle axial traverse, spindle boxes
along the z axis line of the direction of coordinates moving parallel to the main axis degrees, the spindle moving in the z-axis coordinates of the straightness and spindle rotation axis of the vertical line of the work table and so on.
Common testing tools precision spirit level, precision square box, dial gauge or a micrometer table, right-angle instrument, flat feet, high-precision spindle mandrel and the dial gauge pole magnetic blocks and so on.
1.1 Detection method:
The geometric accuracy of CNC machine tools and general machine detection methods are similar to testing requirements to be higher than the general machine tools.
1.2 detection of Note:
(1) detection, the base of the machine should have been completely cured. (2) detection when detection tools and to minimize the error detection methods. (3) shall be in accordance with relevant national standards, first connected to the power of the machine tool preheating, and let all along the machine axis reciprocating motion several times to make medium-speed spindle in order to run for a few minutes before. (4) The geometric accuracy of CNC machine tools in general higher than normal. Ordinary machine tools used for inspection tools, measuring tools, often because of their low precision can not satisfy the testing requirements. And the detection tool used in the precision class of the geometric accuracy than the measured one. (5) The geometric accuracy of precision machine tools must be debugged once completed, shall not transfer a measured one, because some of the geometric precision of mutual contact and influence. (6) large-scale NC machine tools load test should be implemented to test whether the design of machine tool bearing capacity; in load state agencies is working properly; machine works steadily, accuracy, reliability and whether or compliance.
In addition, load test before and after the geometric precision of machine tools should be tested. Test the accuracy of the work load test should be completed.
2. the positioning accuracy of CNC machine tools
CNC machine tool positioning accuracy is defined as the measured moving parts in CNC machine tools under the control of movement can achieve position accuracy. The accuracy and precision of the machine geometry, as would have an important impact on precision cutting machine tools, in particular, will affect the processing time of the pitch error of
the pore.
Measurement of linear motion detection tools: standard length of the groove feet into blocks of rules, micrometer, optical reading microscope and dual-frequency laser interferometer and so on. Standard length measurement with dual-frequency laser interferometer measurement results shall prevail. Rotary motion detection tool 360 tooth precision indexing of the standard turntable or angle polyhedron, high-precision radial grating and parallel fluorescent tubes, etc.. At present a common detector for dual-frequency laser interferometer.
2.1 Detection Method (using dual-frequency laser interferometer pm)
(1) Installation and regulation of dual-frequency laser interferometer.
(2) preheating laser device, and then enter the measurement parameters.
(3) in the machine in motion under the positioning accuracy of machine tools to measure.
(4) The output data processing results.
2.2 The detection of Note:
(1) The instrument should be accurate calibration before use.
(2) The pitch error compensation, should be adjusted after completion of the geometric precision machine carried out in order to reduce the geometric precision of the positioning accuracy.
(3) for pitch error compensation of high-precision testing instruments should be used (eg laser interferometer) for measuring first and then the compensation should be re-compensated measurements and should be the appropriate analytical standards (VDI3441, JIS6330) on the measurement data analysis, until it reaches the machine tool positioning accuracy. Reposted elsewhere in the paper for free download.
(4) machine tools, pitch error compensation methods, including linear shaft rotary axis compensation and compensation for these two methods can be right linear axis and rotary table positioning accuracy of compensation, respectively.
3 Cutting Accuracy
Checking the accuracy of machine tool cutting checks, under the conditions in the cutting tool geometry on the accuracy and positioning accuracy of a comprehensive
examination, including the individual machining accuracy and the processing of checking the accuracy of the cast iron specimen examination (standard carbide cutting tools use cutting) . Examination items generally include: boring hole dimensional accuracy and surface roughness boring shape and pitch accuracy, precision flat end milling cutters, side milling cutter on the side of a straight line accuracy, side milling cutter on the side of roundness accuracy, axis of rotation switch 900 side of the right-angle milling cutter precision, two-axis accuracy.
4 References
1. Week, M., Handbook of Machine Tools, John Wiley & Sons, New York ,1984.
2. The Working Papers of the MIT Commission on Industrial Productivity,MIT Press, Cambridge, MA 1989.
3. Lange, K., Handbook of Metal Forming, McGraw Hill, New York,1985.
4. Kalpakjian, S., Manufacturing Engineering and Technology, A^^ Edition,Prentice Hall, 2000.