共查询到20条相似文献,搜索用时 31 毫秒
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We have developed a simple and low-cost optical measurement system for the simultaneous measurement of the five-degrees-of-freedom error motions of high-speed microspindles. We demonstrated the usefulness of the system by using it to measure actual spindle rotation errors, and analyzed the major error factors. First, the measurement error due to the form error of the lens was analyzed by ray tracing. Second, we analyzed the measurement error due to a displacement of an irradiation laser point on a 3 mm diameter ball lens. Furthermore, we investigated the effect of the centrifugal force and the crosstalk problem of multiple laser beams. The results indicated that a form error of the rod lens significantly affected the measurement accuracy and that a change in the laser beam irradiation point of the ball lens due to a radial displacement had no significant effect on the measurement accuracy. Finally, we confirmed that, owing to the centrifugal force, the measurement accuracy decreased as the speed of rotation increased, and that there was no crosstalk that the reflected and transmitted laser beams in the X direction were detected by the photodiode in the Y direction for displacements within −10 to 10 μm. 相似文献
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A. Shibuya Y. Arai Y. Yoshikawa W. Gao Y. Nagaike Y. Nakamura 《The International Journal of Advanced Manufacturing Technology》2010,46(9-12):845-862
This paper presents a novel spiral scanning probe measurement system which is developed to achieve precise profile measurements of micro-aspheric surfaces. The system consists of a scanning stage (a spindle and a linear slide) and a contact-type displacement sensor. The contact-type sensor is employed for the scanning of the micro-aspheric surface. The micro-aspheric object is set on the spindle, and the contact-type displacement sensor is set on the linear slide. The motions of the spindle and the linear slide are controlled synchronously so that the micro-aspheric object is scanned spirally for high-speed measurement. The motions of the stage are used as the scanning datum for the profile measurement. Because the error motions of the stage are estimated to be on the order of tens of nanometer, these errors are measured and compensated to achieve precise measurements. The alignment error between the spindle rotation axis and the probe tip of the contact-type displacement sensor, which is called the centering error, is confirmed to cause considerable measurement error of the micro-aspheric surface profile. Methods are proposed to make the alignment accurately. Experiments of surface profile measurement of a micro-aspheric lens are also carried out in the measurement system. 相似文献
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Dr E. S. Lee H. G. Wi 《The International Journal of Advanced Manufacturing Technology》1998,14(5):330-335
A method for measuring the accuracy of rotating objects was studied. Rotating axis errors are significant; such as the spindle error of a machine tool which results in increased surface roughness of machined work pieces. Three capacitance-type displacement sensors were used to measure the position of a rotating master ball. The sensors were mounted at the three orthogonal points on the spindle axis. The measurement data were analysed for rotating spindle accuracy, not only for the average roundness error but also for the spindle volumetric positional error during rotation. This method is simple and economical for industrial field use for regular inspection of spindles using portable equipment. The time taken for measurement and analysis using this method is only about two hours. This method can also measure microscopic amplitudes in 3-D directions of vibrating objects. 相似文献
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环锭细纱机纺纱结束后会在锭盘上缠绕尾纱留头,留头率的多少直接关系到机器的性能及劳动量的大小,但是尾纱过多会产生很大的危害,不仅耗费大量的人力,也会造成原料的浪费。就此介绍了两种夹纱形式及其工作原理。 相似文献
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Dongju Chen Jinwei Fan Feihu Zhang 《The International Journal of Advanced Manufacturing Technology》2012,63(5-8):457-464
This paper presents an identification method for the spindle rotation error from the flatness error in the workpiece surface. The spindle rotation error is identified by the wavelet transform, Weierstrass function, and power spectral density (PSD). The flatness error comprises various errors of the machine tool, such as spindle rotation error, guideway error, motor error, and ball screw error, therefore, wavelet transform is used to process the measured result of the workpiece and the signal is decomposed into high-frequency and low-frequency signal. Weierstrass function is used to fit the spindle rotation error. According to the PSD analysis of the processed signal in the frequency domain, the spindle rotation error is identified from the measured flatness error, this method provides a basis for the identification of machine tool errors. 相似文献
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Case study: A comparison of error sources in high-speed milling 总被引:2,自引:0,他引:2
Tony L. Schmitz John C. Ziegert J. Suzanne Canning Raul Zapata 《Precision Engineering》2008,32(2):126-133
This paper describes a case study devised to quantify the relative contributions of geometric, thermal, contouring, and cutting force errors to machined part dimensional errors. Measurements were performed to independently evaluate the: (1) quasi-static geometric errors using the laser ball bar; (2) variations in geometric errors due to thermal effects; (3) spindle thermal growth errors using a capacitance gage nest; (4) two-dimensional contouring errors using a grid plate encoder; and (5) surface location error due to (stable) forced vibrations during cutting. The effects of the first three error components were related to part dimensions using a homogeneous transformation matrix approach integrated into a Monte Carlo simulation. A comparison of the individual influences of these error sources showed that the cutting force error was dominant for the high-speed machining center/tool-holder combination selected for this study. 相似文献
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Spindle thermal drift measurement using the laser ball bar 总被引:1,自引:0,他引:1
Thermally induced errors are major contributors to the overall accuracy of machine tools. An important component of thermally induced errors is the error associated with spindle thermal drifts. In this paper, a novel method is developed to measure spindle thermal drifts in machine tools using a laser ball bar (LBB) as the calibration instrument. The method is implemented on a two-axis CNC turning center. The LBB is used to measure the coordinates of the spindle center and the direction cosines of the spindle axis at various thermal states. The axial, radial, and tilt thermal drifts of the spindle are then computed from the changes in these coordinates. The new method is verified by comparing the spindle drifts measured with the LBB to those measured by capacitance gauges. The results obtained by the new method show good agreement with the capacitance gauge technique. The primary advantage of the new method is the ability to measure the spatial coordinates of the spindle center and direction cosines of the spindle axis with the same instrument used for measurement of the geometric errors of the machine axes. 相似文献
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利用PMAC(Programmable Multi-Axis Controller)-PC作为核心控制器,设计集成了一台新型高速精密磨床.该磨床选用陶瓷球轴承电主轴作为高速主轴系统,利用直线电机作为高速精密进给系统.通过直线电机的定位精度实验及高速磨削电主轴振动实验研究,以及控制系统的仿真分析,证明了该集成系统的可行性. 相似文献
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In this paper, a simple nondestructive method is described to obtain the refractive index profile of a gradient refractive index rod lens by means of optical coherence tomography. The approach exploits the fact that optical coherence tomography provides a direct measurement of the optical path of the light traveled through a gradient refractive index rod lens. The refractive index profile for a gradient refractive index rod lens is retrieved by iterative fitting of the optical path calculated by the ray tracing method with that experimentally measured using optical coherence tomography. The measured refractive index profile is in good agreement with theory. 相似文献
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Reducing the manufacturing time is the trend of high-precision manufacturing, and the precision of a work-piece is very important for manufacturing industry. The high-speed motorized spindle is the most critical part and becoming more widely used in the machine tool at present, and its precision may affect the overall performance of high-speed cutting. Most of the studies on high-speed cutting are focused on the cutting force, the vibration of the spindle and effects of the spindle’s thermal deformations; hence, how to roundly measure and objectively evaluate high-speed spindle is an imminence question of it because the comprehensive dynamic properties and evaluation system of spindles directly affect the cutting ability of the whole machine tool before they are manufactured. This paper presents a comprehensive measurement and evaluation system of high-speed motorized spindle, which reflects the overall performance of motorized spindle and bases on international standard. 相似文献
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In Roll-to-Roll manufacturing of high-quality optical Fresnel lens films, a high-precision roller mold with super-fine surface quality is essential to precisely transfer the functional microstructures from the periphery roller surface onto the flexible substrate. Unfortunately, direct diamond turning of deep circular grooves on the periphery surface of a roller mold was considered infeasible. Recently, the team has developed a novel 4-axis interactive tool-workpiece motion, Rotating-tool diamond turning (RDT), as a solution to overcome this challenge. Experiments were conducted to justify the capability of the proposed RDT process by directly machining a radial Fresnel lens on a brass roller mold, but without precise 3D profile evaluation of the lens on the roller surface. On-machine measurement of the machined lens structures using 3D touch probe is not applicable because the diameter of the probe is relatively large to penetrate into steep grooves of the Fresnel lens. On the other hand, off-machine measurement using stylus profilometer will introduce inevitable alignment errors during the measurement and lead to mismatched machining and measurement coordinates, making it difficult to evaluate the 3D lens profile generated by the RDT process eventually. In this study, a compensation and comparison algorithm is presented to precisely evaluate the form error between the machined and designed features in a three dimensional manner. Alignment errors generated when positioning the roller mold on the stylus profilometer are investigated and quantified through analyzing the characteristics of this unique micro structure with Fresnel lens wrapped on the roller periphery. As a conclusion, the machined lens structure is compensated and restored to compare with the designed profile, and the form error is obtained with the sources of errors analyzed. Such profile compensation and comparison method can be applied in other measurement and characterization studies on evaluation of complex optical structures patterned on roller molds for Roll-to-Roll manufacturing of advanced functional films. 相似文献
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高速主轴系统切削稳定性直接影响产品的表面加工精度和切削系统的使用寿命,是评价高速主轴系统性能优劣的重要因素,而研究影响切削稳定性的因素并制定提高稳定性的合理途径同样也受到关注。提出从稳定性评价准则及系统频响函数的不同求解方法入手,分析无条件稳定区和有条件稳定区的影响因素,总结出系统所受激励、主轴转速及系统结构是影响切削稳定性的重要因素。以德国GMN高速主轴系统为例,在采用5自由度轴承受力与变形关系模型模拟角接触球轴承和分布式弹簧模型模拟主轴-刀柄-刀具结合部的基础上,建立完整高速主轴系统通用有限元模型;利用三维稳定性叶瓣图、极限切削深度和叶瓣交点随参数的变化曲线表征切削力幅值、转速及阻尼比等参数对切削稳定性的影响规律,为优化加工工艺、提高系统切削稳定性提供理论依据。 相似文献
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IMPROVINGACCURACYOFCNCMACHINETOOLSTHROUGHCOMPENSATIONFORTHERMALERRORSLiShuheZhangYiqunYangShiminZhangGuoxiongTianjinUniversit... 相似文献
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在太赫兹时域波谱系统中,通过光学延迟线的时间延迟实现对太赫兹时域信号的采集,而传统的光学延迟线存在扫描速度慢、光学延迟分辨率低等问题。为此,提出了一种采用磁杆直线电机作为驱动和传动一体装置,并加入光栅测量系统的光学延迟线改进方案。测试结果表明,该方案可实现长距离内高速、精准往复运动,同时提供高达512 ps的延时范围和0.033 fs(位置定位精度0.01μm)的光学延迟分辨率,显著提高了太赫兹时域波形振幅的稳定性。 相似文献
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This paper describes the development and application of a system for assessing the contouring characteristics of feed drives on computer numerically controlled (CNC) machine tools. The hardware comprises two linear digital displacement sensors mounted orthogonally on the work table of a CNC machine tool and operating against a precision cube, located in the spindle. Simultaneous movements of two machine axes are measured by the sensors, in conjunction with a microcomputer. Therefore, this system is capable of detecting the difference between a programmed and actual path. By using both circular and square corner programmed test paths, the system can evaluate servo-induced errors in machine tools. Application of the system to the X- and Y-axes of a machining center is undertaken, and results are shown for a range of contouring frequencies and gain settings of the axes. Comparative tests are also undertaken using a conventional double ball link bar, which is shown to be an inferior technique for characterizing the servoerrors. 相似文献
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