高精度石英全息透镜的MEMS工艺制作

通过微电子机械技术(MEMS)在抛光的熔融石英基材表面制作了平面精度达到0.4μm的超大单片面积的全息透镜。采用了分辨率达到0.2μm的步进投影式拼接光刻,适合石英基材的专用等离子耦合刻蚀(ICP)干法刻蚀技术,特殊的物理清洗方法,以及相关的多项辅助工艺。透镜理想面形横截面曲线为分段抛物线,每一片由23个柱状结构单元周期横向排列构成,采用等深度不等宽度的4台阶结构拟合,单元宽度约为2.966mm。在4in(10.16cm)圆片上,获得了单片尺寸为68mm×68mm的方形透镜。采用接触式台阶仪,扫描电子显微镜(SEM),高倍光学显微镜等方法进行不同阶段检测。结果显示:台阶平面精度为0.4μm,垂直精度为30nm,有非常好的立墙陡直度和刻蚀均匀性。此工艺方案可实现小规模批量生产,成本适中,可以直接用于制作6in(15.24cm)以上同等级要求的石英透镜,经适当改进也可用于蓝宝石等基底材料的制作。     

陶瓷球混合轴承中陶瓷球的高表面完整性精密加工

主要介绍了动压浮起平面研磨、浮动抛光、磁流体浮动抛光以及化学．机械抛光等陶瓷球的高表面完整性加工方法，不仅得到了理想的光滑表面，而且无加工变质层和表面损伤，满足了生产上对陶瓷球轴承的使用要求。     

一种高精度石英挠性加速度计自动测试系统设计

石英挠性加速度计(简称石英加表)作为惯性平台的核心器件,其精度、可靠性是国内外研究的重点。该文研发了一套加速度计自动测试系统,采用强制均温和半导体制冷片调温的温控仪实现了采样电阻的精确温控,可针对不同采样电阻对测试精度的影响,应用采样电阻补偿算法,有效提高了温度稳定性和采样测量精度。经试验验证,采样电阻最小误差为百万分之4.3,可控采样电阻温度变化小于0.02℃,输出最大温度漂移为0.01 V,满足实际工程需求。     

Self-generation of machining precision and its realization in lapping of super precision solid balls

This paper presents the principle of self-generation of machining precision by explaining its basic concept and five necessary conditions for forming a system with self-organization capability. A self-generation system is a kind of system with self-organization capability. The self-generation of machining precision for solid balls with super precision is emphatically explained. From the viewpoint of self-organization, there are three types of systems including system S1 with the self-regulation capability, S2 with the self-determination capability of goals, and S3 with the self-organization capability. Although they are all closed loop control systems, they have different constructions and functions. Necessary conditions for achieving self-generation of machining precision are given. Establishment of the system for machining solid balls with super precision is discussed. Self-generation of machining precision for solid balls with super precision on the basis of the capability of self-removal of errors is presented. Self-generation includes the ability of self-removal of errors for solid balls, convergence of self-removal of errors, self-generation of precision, and self-generating system for the given.     

Self-generation of machining precision and its realization in lapping of super precision solid balls

This paper presents the principle of self-generation of machining precision by explaining its basic concept and five necessary conditions for forming a system with self-organization capability. A self-generation system is a kind of system with self-organization capability. The self-generation of machining precision for solid balls with super precision is emphatically explained. From the view-point of self-organization, there are three types of systems including system S1 with the self-regulation capability, S2 with the self-determination capability of goals, and S3 with the self-organization capability. Although they are all closed loop control systems, they have different constructions and functions. Necessary conditions for achieving self-generation of machining precision are given. Establishment of the system for machining solid balls with super precision is discussed. Self-generation of machining precision for solid balls with super precision on the basis of the capability of self-removal of errors is presented. Self-generation includes the ability of self-removal of errors for solid balls, convergence of self-removal of errors, self-generation of precision, and self-generating system for the given. __________ Translated from Chinese Journal of Mechanical Engineering, 2007, 43(9): 75–79 [译自 机械工程学报]     

精密球研磨加工中振动信号的检测与分析

由于轴承精密球的精度直接影响轴承的运动精度及寿命,利用加速度计传感器、数据采集卡和Lab VIEW,设计了一套测试振动信号的检测设备,对精密球在研磨加工过程中产生的振动信号进行了测试,从时域、频域等多个角度进行了分析论证.分析结果表明,利用精密球体研磨加工中产生的振动信号能有效地监控整个研磨加工过程,并能实时地反映球体研磨的状态和精度.     

Thread grinding of precision quartz solenoids to international electrical standards

International specifications regarding quarts solenoids have recently changed. This study describes the grinding of a precision thread along the quartz bobbin of such a solenoid. Fused quartz being a grinding resistant material, the optimal grinding conditions were clarified. A closed-loop compensation system was applied in which a magnetic scale was used to measure the table feed of the thread grinding machine, resulting in a quartz solenoid of high pitch accuracy.     

Lapping high precision polygonal shafts

Lapping has been used as a finishing method to improve roundness accuracy of cylindrical shafts and holes. However, little has been published on the theoretical analysis of the finishing mechanism for high precision polygonal cross sections. This paper offers a method for finishing polygonal shafts, whose shapes are ellipsoidal, triangular, four-lobed and so on. By this method, the amplitude can be increased for any Fourier component of out-of-roundness. Special types of lapping tools were produced by applying the ‘V-block’ roundness measuring method. Using one of the V-block lapping tools, the magnitude for the four-lobed component was increased form 8.4 μm to 9.9 μm, while the other components were decreased; out-of-roundness improved from 35 μm to 25 μm. By setting the angle between the supporting teeth at an appropriate value, any polygonal shaft can be finished with these laps. This method is also applicable to finishing polygonal holes     

A high precision straight-motion system

In this system, a steel block is completely floated by air pads mounted on a mechanical sliding table. When the table moves, the vertical and horizontal positions and the pitch, roll and yaw angles of the block change because of the misalignment of the sliding table. These changes are detected against references by optical and electronic devices and the positions and angels of the block controlled by changing the supply pressure to each pad. Straight-edge masters and a laser straightness interferometer are used as the references for vertical and horizontal straightnesses, and autocollimators are used to detect the change in pitch and yaw angle attitudes. As a reference to the roll angle attitude, the two straight-edge masters are used. The working length of the system is 1 m. The positional errors of the block motion with respect to the references are less than 0.1 and 0.4 μm and the angular changes are less than 0.2 s of arc.     

高温回火钢球超精研加工方式改进

高温回火钢球表面质量是长期以来急需解决的问题。通过改进超精研加工工艺及加工过程,提高了钢球的外观质量和表面粗糙度及生产效率,使该类轴承的性能和寿命有了进一步的提高。     

不同结合剂金刚石锯片精密锯切石英玻璃研究

探讨石英玻璃的精密锯切,通过两种不同结合剂的金刚石薄锯片对石英玻璃进行精密锯切,测量和分析锯切过程中的锯切力,并结合锯切力比、比能来研究不同结合剂金刚石锯片对石英玻璃的锯切特征。结果表明:随着切深和进给速度增大,锯切力增大;随着锯片转速增大,锯切力减小,力比在2.11~2.46之间,接近于金刚石砂轮磨削硬质合金的力比,比能在4"10J/mm3之间,树脂锯片锯切石英玻璃的锯切力和锯切比能较金属锯片小,而锯切力比较金属锯片大。     

一种高精度失真度测量仪的研制

针对国产失真度测量仪的技术现状,本文开发了一种具有高基波抑制度、低谐波衰减率的有源T型桥基波抑制电路,提出了频率自动调谐方法,设计了实现该方法的电路,提高了失真度测量仪技术水平。实践表明：该失真度测量仪结构简单、精度高、测量范围宽、操作方便、价格低。     

高精度直流电流稳流源数控系统设计及实现

以AT89S52为核心,通过A/D、D/A转换和V/I转换及独特的算法实现高精度的电流控制,电流输出范围为20~2000mA的数控直流电流源。该电流源具有电流可预置,lmA步进,同时显示给定值和实测值等功能。     

采用高速高精度磨削的优点

分析高速高精度磨削工艺,提出其可以提高工件表面质量和加工精度及磨削效率,且操作简便,成本低.     

Study on magnetoresistive rotameter with high precision

Based on the detection mechanism of Quadrupole magnet, a high precision magnetoresistive rotameter is proposed in this paper. It mainly describes the signal processing method of rotameter, the design of system, the calibration experiments of the prototype and the result analysis. Offline simulation is carried out to improve the transducer structure, which shows that the meter's overall performance could be improved with the novel method. Experimental results and error analysis indicated that the precision of the magnetoresistive rotameter is better than 1%, with its grade at level 1.     

高精密转台标定方法研究

针对特定情况下高精密大型转台定位精度的标定问题,提出了一种采用激光跟踪仪标定的方法,首先分析影响标定方法精度的因素,通过优化测量参数及采样策略,建立基于激光跟踪仪的最优标定系统,拟合激光跟踪仪测得点所在的三维平面,通过坐标变换将测量点转换到二维平面上,拟合转换后的数据得到圆心坐标,最后计算相邻测量点与圆心连线的夹角,与理论值进行比较,从而确定转台的定位精度。实验表明,标定系统的精度满足要求。该标定方法简单可靠,提高了高精密大型转台的标定效率。     

Development of a high precision flexure-based microgripper

This paper presents the design and development of a high precision microgripper for micromanipulation. The design is based on a hybrid flexure-based compliant mechanism and a bias spring structure which render high fidelity and inherent mechanical advantages. Finite element analysis (FEA) was conducted to evaluate responses of the model under specified load and displacement to investigate optimum design of the model. The prototype of the proposed microgripper was fabricated using electro-discharge machining (EDM) process. An experimental study of the performance was carried out and the results are presented. The experimental results are also compared with the computational analysis results. The results show that a high level of displacement amplification and a maximum stroke of 100 μm can be achieved.     

高精度绝对式编码器的研发与应用

一、概述随着我国机床、伺服电机行业的迅速发展,对伺服电机的转速、精度及功能作用的要求越来越高,而伺服电机的这些功能主要取决于编码器的精度,需要编码器有更高的采样精度和数据位数。由于绝对值编码器在编码器内部所有位S值在编码生成后,其堡程内所有的位置均有一一对应的代码(二进制、BCD代码)输出。