提高车削金属表面粗糙度的技术研究

针对目前许多机械企业金属零件表面粗糙度的控制、质量与效益矛盾的问题,对表面粗糙度形成的相关因素进行理论分析,并结合实践总结出一系列有效措施,使车削金属的表面粗糙度明显提高,加工后的金属工件符合设计要求,加工效率明显提高.     

基于最小二乘支持向量机的外圆磨削表面粗糙度预测系统

为解决磨削加工中影响因素多,难以实现自动化加工的困难,对磨削系统的表面粗糙度预测系统进行了研究。在分析目前常用预测方法的基础上,建立了基于最小二乘支持向量机的外圆纵向磨削表面粗糙度预测模型。该模型采用等式约束,把原来求解一个二次规划问题转化成求解一个线性方程组,方法简单且有效。比较实验显示,该方法响应时间快、测量精度高,测量精度误差比BP神经网络预测方法小4%,比进化神经网络(BP+GA)预测方法小1.3%,所提供的预测方法可以实现对工件表面粗糙度的在线预测。将其应用于外圆纵向磨削智能系统中,实时计算预测值与给定粗糙度的差值,引导磨削专家系统修正磨削参数,实现智能控制,取得了较好的效果。     

确定机械零件表面粗糙度的灰色关联方法

基于灰数白化及灰色关联分析的理论,建立了一套确定机械零件表面粗糙度的灰色关联方法,并结合某坦克变速箱主轴支承轴颈表面粗糙度值确定的实例,说明了该方法的应用和特点。该套方法具有普遍意义,可推广应用于机械设计的各个方面,     

An in-line digital filtering algorithm for surface roughness profiles

The authors develop a fast algorithm for low- and high-pass Gaussian digital filters, executed while one discrete datum of a traced profile is sampled. In this report, the 8-step, modified running–box-function filter is presented. The transmission characteristics of this new filter are very close to those of the Gaussian digital filter given in ISO 468-1982. In addition, the conditions for using this filter are given for practical use.     

机械零件表面粗糙度的影响与选择

从摩擦学的角度出发 ,阐明对于配合表面只取Ra值时的不足 ,建议应当再增加一个表面纹理加工方向 ,以此确保配合表面的润滑效果 ,减少磨损 ,提高使用寿命。     

三维表面粗糙度的表征和应用

表面粗糙度会直接影响零部件的耐磨性、密封性以及抗腐蚀性等,是评定机械加工和产品质量的重要指标。现代科技水平的不断提高对零件表面性能的要求也日益严苛。传统的二维表面粗糙度的测量和表征已经不再能够满足技术发展的要求,三维表面粗糙度由于能够更加全面、真实地反映工件表面的状态而受到人们的重视,成为研究热点。本文回顾了三维表面粗糙度的发展历史,系统地介绍了三维表面粗糙度参数及标准的发展现状,分析了表面形貌与功能特性的联系,概述了三维粗糙度参数在制造业、生物医疗、摩擦学与材料科学等领域的广泛应用,并进一步指出了三维表面粗糙度表征和应用的发展方向。未来随着相关研究(比如,三维测量的溯源性、重复性、参数表征体系等问题)的深入以及三维表面测量手段的发展,三维表面粗糙度参数也将不断完善和推广,并更多地与实际功能相结合来预测并指导生产,确保工件的表面质量。     

A new optical technique for roughness measurement on moving surface

A new optical technique which allows the roughness of moving surfaces to be determined was developed. The new technique which is called the dark/bright ratio (DBR) method utilizes the combined effects of speckle and scattering phenomena. The roughness of surfaces is inferred from the dimensions of the recorded dark or bright area in the speckle pattern. Although it is a relative method, it has great potential to be used for in-process measurement and automation owing to the simplicity of both its principle and required optical set-up. The new technique has also been proved to have large measuring range and with high precision. The principle of this technique and the set-up of the measuring system are described. Experimental results for both static and dynamic conditions, which were compared to those obtained using the traditional stylus technique, were found to be in good agreement. The reliability of the new technique in obtaining roughness data of surfaces under various speed conditions (from 0 to 0.017 m/s) was validated.     

表面粗糙度测量方法综述

表面粗糙度是机械加工中描述表面微观形貌非常重要的一个参数,表面粗糙度测量技术是现代精密测试计量技术的一个重要组成部分。综述了接触式和非接触式两类测量方法,着重介绍了非接触式测量中的几种测量方法的测量原理及其优缺点。     

表面粗糙度标准装置不确定度分析

通过对表面粗糙度标准装置的不确定度分析,证明了其测量能力具备了量值传递的资格。     

三维表面粗糙度测量方法综述

表面粗糙度测量是评估零件表面特性的重要手段。经过二十多年的发展,三维表面粗糙度逐渐成为反映工件表面特性的重要指标。本文总结并比较了多种三维表面粗糙度的测量方法及特点,根据测量过程是否接触被测表面,将三维表面粗糙度测量方法分为接触式测量法与非接触式测量法。接触式测量法主要包括触针扫描法;非接触式测量法主要包括光学法(相移干涉显微法、相干扫描干涉法、数字全息法、共聚焦显微法、共聚焦色差显微法、点自动对焦法、变焦法、激光三角法和光切法)和电镜法(扫描电子显微法、扫描隧道显微法、扫描近场光学显微法和原子力显微法)。针对每种测量方法的发展现状,本文讨论了其适用范围及局限性,并指出未来的发展方向。     

In-proces sensors for surface roughness and their applications

Potential non-contact optical methods for in-process surface roughness measurement are described, including reflected light position detection, focu     

A dynamic surface roughness model for face milling

This paper presents a newly developed mathematical model for surface roughness prediction in a face-milling operation. The model considers the static and the dynamic components of the cutting process. The former includes of cutting conditions as well as the edge profile and the amount of runout of each insert set into a cutter body. The latter introduces the dynamic characteristics of the milling process. It is verified that such a model predicts the maximum or the arithmetic mean surface roughness value through the cutting experiments. The model can evaluate the surface texture of the precision parts machined with face milling.     

Wide range three-dimensional roughness measuring system

A wide range three-dimensional roughness measuring system is described. A precision x-y traversing table moves the sample and surface asperity heights are measured with a conventional stylus profilometer. The system can measure an area of $\text{300}\text{mm × 400 mm}$ and divide the area into $\text{5 × 19}{}^9$ different locations. A new plot program which gives a true perspective picture is used, a new way of presenting the bearing area is shown and possibilities for studying exactly the same spot between experiments are given. A method for eliminating the vibrations from the system is also given.     

A vision system for surface roughness assessment using neural networks

In this study we use machine vision to assess surface roughness of machined parts produced by the shaping and milling processes. Machine vision allows for the assessment of surface roughness without touching or scratching the surface, and provides the flexibility for inspecting parts without fixing them in a precise position. The quantitative measures of surface roughness are extracted in the spatial frequency domain using a two-dimensional Fourier transform. Two artificial neural networks, which take roughness features as the input, are developed to determine the surface roughness. The first network is for test parts placed in a fixed orientation, which minimises the deviation of roughness measures. The second network is for test parts placed in random orientations, which gives maximum flexibility for inspection tasks. Experimental results have shown that the proposed roughness features and neural networks are efficient and effective for automated classification of surface roughness.     

钢球表面粗糙度评定方法的探讨

通过对现行钢球表面粗糙度标准中和英国Talysurf轮廓仪说明书中有关参数的对比分析,对钢球表面粗糙度评定方法提出了新的看法。     

纵-扭复合振动超声深滚表面粗糙度研究

将纵-扭复合振动超声加工与常规深滚加工工艺相耦合,创建纵-扭复合振动超声深滚加工工艺,并对其加工原理进行阐述。理论分析了超声振动对表面粗糙度的影响;采用单因素试验法对6061-T6铝合金轴件进行常规深滚与纵-扭复合振动超声深滚处理,研究深滚工艺参数对工件表面粗糙度的影响。试验结果表明:在相同的工艺参数下,辅助纵-扭复合振动后,超声深滚所获得的表面粗糙度Ra值均小于常规深滚,且在设定参数范围内,静压力对表面粗糙度的影响最为显著,最高降低约50%。     

Evaluation of discrete displacement transducer by spectral analysis of surface roughness

A discrete displacement transducer using an optical technique and attached to a commonly used stylus instrument is described. The proposed transducer plays an important role in generating a digital output of surface profile from the viewpoint of sampling error. The working accuracy is discussed with reference to the spectral analysis of surface roughness.     

Fuzzy-nets-based in-process surface roughness adaptive control system in end-milling operations

A fuzzy-nets-based in-process adaptive surface roughness control (FN-ASRC) system was developed to be able to adapt cutting parameters in-process and in a real time fashion to improve the surface roughness of machined parts when the surface roughness quality was not meeting customer requirements in the end-milling operations. The FN-ASRC system was comprised of two sub-systems: (1) fuzzy-nets in-process surface roughness recognition (FN-IPSRR); and (2) fuzzy-nets adaptive feed rate control (FN-AFRC) sub-system. To test the system, while the machining process was taking place, the FN-IPSRR system predicted the surface roughness, which was then compared to the desired surface roughness. If the desired surface roughness was not met, then, the FN-AFRC system proposed a new feed rate for the machining process. Once the feed rate was changed, and the cutting continued, the output of the surface roughness of the new feed rate was compared with the desired surface roughness. This proposed FN-ASRC system has been demonstrated to be successful using 25 experimental tests with 100% success rate.     

小波滤波及奇异性分析在三维表面形貌评定中的应用

在机械加工领域,表面信息对于表面加工的指导作用至关重要。相对于表面二维信息,三维表面结构信息更能充分反映加工表面的实际特征,是热点研究问题。由于测量仪器的机械传动系统和测量环境等震动因素的存在,接触式测量方法得到的表面信号往往包含震动带入的误差信号,而这些信号存在其自身特点——奇异性特征。目前,小波变换是用于信号处理的有效工具。为透彻分析表面信号并剔除震动误差信号,本文介绍了通过小波变换对奇异信号进行检测的原理,并且给出了具体算法。在实验中利用该方法对表面测量信号进行预处理,并用小波滤波将表面结构分解得到粗糙度尺度轮廓,对其三维典型参数进行了计算,并与高斯滤波得到的粗糙度评定参数进行了比对。计算和比对表明小波奇异性分析是有效的,可得到更加合理的评定结果。     

New approaches to surface roughness evaluation of special surfaces

This work concerns itself with two approaches to the evaluation of surface roughness parameters. The first approach identifies vacancies in the surface and removes them from calculations. The second approach uses the parameters defined in German standard draft DIN 4776 E. The advantages and disadvantages of both methods are discussed and their potentials evaluated for different assignments.