磨料磨具的发展趋势

磨削是用不确定的刀刃来切削的加工.目前的磨削技术,不仅对磨床设备提出了新的要求,而且对磨削工具也提出了更高的要求.为了提高精度、提高效率、降低成本,各磨料磨具厂商在各方面作出努力,来适应和开发新产品,提高他们各自的竞争能力.结合我国目前的实际情况,我认为将来的发展趋势有以下几个方面:     

磁流研磨参数对钢球研磨效率及研磨机理的影响

以滚动轴承钢球体为对象,在试验和微观分析的基础E探讨了磁流研旁过程中工况参数的变化对钢球研磨效率和机理的影响.研究结果表明:几乎所有的研磨工况参数都影响到研磨效率.然而,磁浮力的变化不仅影响到研磨效率而且影响到研磨机理.在一定的磁浮力范围内,钢球的研磨机理为微切削,而当磁浮力达到2.5N时,钢球表面呈现疲劳剥落和凿削微坑.进一步讨论了影响研磨效率的工况范围.     

Design of grinding plates for a universal grinding machine

New designs of cover plates and grinding plates for a universal grinding machine are developed. These designs greatly expand the functional capabilities of the machine. The plates are durable and their operating costs are low.     

Research on constant grinding depth model for cam grinding

In order to mitigate the problems in CNC grinding of a camshaft caused by varying grinding depth along the periphery of the cam, a novel grinding strategy is proposed to keep the grinding depth constant during the process. In comparison with the current cam grinding strategy, analysis results derived from the modelling of the process indicate that it is applicable to keep the grinding depth constant. Consequently, in combination with a constant grinding infeed speed, the material removal rate (MRR) is also kept stable. With the same grinding depth, the volume of removed material in a certain single revolution with the new processing strategy is less than the conventional process. This new strategy can increase the grinding depth without causing grinding burns. Therefore, the total number of grinding revolutions/steps decreases dramatically. Moreover, experiments for comparison of both the single revolution machining and the whole cam grinding have been carried out on a CNC8325B camshaft grinder. The results show that the new process improves machining efficiency dramatically while ensuring the machining quality.     

无心磨床砂轮主轴的涂镀修复

无心磨床的砂轮轴经过几年的运转,由于轴径部位的磨损过限,造成不能正常工作。通过磨削去除轴径的疲劳层,再进行表面涂镀修复,最终达到修复砂轮主轴的目的。     

金刚石微粉砂轮超精密磨削技术

论述了金刚石微粉砂轮超精密磨削的特点、存在的技术难题及其发展前景。对金刚石微粉砂轮超精密磨削机理进行了探讨，认为它是以微切削为主的多种作用的融合；研究了金刚石微粉砂轮修整机理及其常用的有效修整方法；提出了树脂-金属复合结合剂金刚石微粉砂轮的构想，论述其结构的形成、制作过程及其实际磨削效果；最后，探讨了进行金刚石微粉砂轮超精密磨削时的影响因素及环境条件。     

高速深磨磨削表面烧伤的实验研究

高速深磨磨削表面烧伤研究是高速深磨的非常重要的内容。文章通过测量40Cr钢高速深磨磨削试件表面烧伤层的深度,观察磨削表面质量,分析了高速深磨各种工艺参数对磨削烧伤层厚度的影响规律,研究了避免磨削烧伤和磨削裂纹的高速深磨磨削参数优化准则。     

成形砂轮磨齿工艺中磨削烧伤缺陷的研究与防止对策

根据成形砂轮磨齿工艺的特点,说明磨削烧伤产生的原因,经过分析研究与实践,给出烧伤缺陷的防止对策.     

砂轮平衡及其在磨削工程中的应用

在机械制造领域,磨削加工以其不可替代的优势,通常作为机械零件的最后加工工序.但是,磨削加工过程中却时常出现振动,致使磨削振纹成为提高零件表面质量的主要障碍.为此,全面梳理了回转体不平衡、砂轮不平衡、磨削振动和砂轮平衡精度等相关内容;分析了砂轮平衡主要表征参数、砂轮不平衡影响因素和砂轮平衡测试技术等;最后,基于磨削工程应...     

光学玻璃的激光微结构化砂轮精密磨削

为了降低大磨粒金刚石砂轮磨削光学玻璃时的亚表层损伤,利用纳秒脉冲激光对金刚石砂轮进行了表面微结构化加工,并采用该砂轮研究了光学玻璃的精密磨削加工。首先,计算了金刚石磨粒在纳秒脉冲激光辐射下的烧蚀阈值和激光束腰半径;然后,分析了纳秒脉冲激光在金刚石磨粒上加工的微结构形貌以及微结构化过程中的热损伤;最后,采用微结构化大磨粒金刚石砂轮进行光学玻璃的磨削实验,并分析了亚表层的损伤情况。实验结果表明:金刚石磨粒在纳秒脉冲激光辐射下的烧蚀阈值为0.89J/cm,激光束腰半径为17.16μm。在粒度为150μm的大磨粒电镀金刚石砂轮上可以实现结构尺寸为20μm的微结构表面加工。与传统金刚石砂轮相比,微结构化砂轮磨削后的光学玻璃亚表层损伤深度降低了40%,达到了降低光学玻璃磨削亚表层损伤的目的。     

2.5D玻璃磨削夹具设计及磨削实验研究

2.5D玻璃已应用于手机屏幕镜片,由于玻璃材料硬度高、脆性大,需要采用精密磨削的方法加工。首先根据磨削力计算出吸附力,然后设计出一款真空吸附的手机镜片磨削夹具,可以保证玻璃在高速加工时的精准定位;最后通过实验研究2.5D玻璃的磨削过程,得到的玻璃镜片无外观缺陷,尺度及精度满足图形尺寸公差的要求。     

Precision centreless grinding

Centreless grinding is widely used in volume production because of its inherent advantages for high productivity. This article^* attempts to relate sources of workpiece inaccuracy to aspects of machine design and, using fuel injection needles as an example, show how the advantages of high productivity can be combined with high precision production     

Specific grinding energy as an in-process control variable for ductile-regime grinding

This article addresses the problem of monitoring the material removal regime (ductile versus brittle) that occurs during the grinding of brittle materials. Often a ductile grinding regime is desired, but currently there is no way to measure the grinding ductility “in process.” A model is developed to describe the dependence of the specific grinding energy on the material removal regime. It is found that the specific grinding energy will remain relatively constant for ductile-regime grinding but will decrease in a power-law relationship with an increasing material removal rate for brittle-regime grinding. Experimental confirmation of the proposed model is presented. The potential for using measurements of specific grinding energy to control the grinding ductility is established, and the benefits of such a closed-loop feedback system in ductile-regime grinding are explained.