成形砂轮修整技术研究现状

介绍了修整成形砂轮常用的金刚石笔修整、金刚石滚轮修整、GC杯形砂轮修整、点挤压修整、电加工修整方法的整形原理和特点。并分析了目前成形砂轮修整中存在的问题及发展趋势。     

曲轴机加工砂轮修整精度及参数优化研究

该文针对砂轮修整后砂轮尺寸精度存在误差、砂轮修整参数未标准化等问题进行研究。通过分析砂轮修整过程，识别出回弹量与磨损比这两个影响修整精度的关键因素。设计试验验证了线速比、修整次数及进给量对修整后砂轮表面状态的影响，并调整优化修整参数，实现了修整后砂轮尺寸精度的提升以及曲轴加工表面粗糙度合格率的提升，减少了工件报废率，节约了成本，对于磨床加工中的砂轮修整过程具有重要的参考价值。     

螺纹磨床摆缸修整器

螺纹磨床中的砂轮修整器是用来修整各种螺纹牙形的砂轮,对螺纹进行精加工磨削。通过研究螺纹磨床摆缸修整器的机械结构,针对机械传动砂轮修整器所存在的问题,介绍了摆缸传动砂轮修整器的原理与结构,其中包括摆缸圆弧砂轮修整器和摆缸三角砂轮修整器,收到明显的效果,可为精密螺纹磨削提供参考。     

3MZ146外沟磨床砂轮修整器的改进设计与应用

3MZ146外沟全自动高速外沟磨床原采用的砂轮修整器是通过钢丝和回转轮将油缸活塞的往复运动转换成金钢笔的回转运动，从而实现砂轮的修整。由于传动不平稳造成砂轮修整不圆，严重影响产品质量。为解决上述问题，重新设计了一套回转油缸式砂轮修整器，使传动平稳，砂轮修整质量较高，较大地提高了套圈沟道磨削的圆度和光度，完全消除了原砂轮修整器存在的缺陷。     

陶瓷结合剂CBN砂轮的修整

研究了砂轮修整方法对陶瓷结合剂CBN砂轮摩削效果的影响。研究结果表明，用单粒金刚石修整陶瓷结合剂CBN砂轮时，修整后的砂轮表面层磨粒钝化，磨削力大，磨削质量差。用碳化硅砂轮或磨削油石法修整的陶瓷结合剂CBN砂轮则可避免初期磨削力大的问题。     

渐开线成形砂轮的修整方法

成形磨齿的关健是渐开线成形砂轮的修整问题。一、成形砂轮修整方法分类按修整工具可分为金刚笔修整、金刚滚轮修整和金刚砂带修整。根据砂轮修整整得到的齿形曲线,成形砂轮修整方法又可分为近似曲线逼近修整方法和理论上准确的齿形曲线修整方法。主要修整方法见下表。     

砂轮修整器

通常修整砂轮时,把若干个砂轮修整片装在砂轮修整架上,完全靠手支撑并左右移动修整架,利用砂轮的转动带动修整片旋转的差动力,实现砂轮的修整。这种传统修整砂轮方法会出现以下情况:第一,砂轮修整片磨损快并且在使用过程中孔的间隙变大,影响修整精度。第二,操作过程稳定性差,有一定的危险性。第三,被修整的砂轮表面较粗糙、圆柱度差。第四,不能完全消除砂轮运转产生的径向跳动,此项是影响砂轮使用的关键。现用我们自行设计制作的砂轮修整器进行修整砂轮后,以上的问题都能迎刃而解,并且修整后砂轮运转时平稳、噪声也较小。1·砂轮修整器的结…     

采用超硬砂轮修整机修整金刚石砂轮的试验研究

在采用自主研发的具有在线检测技术的超硬砂轮修整机修整各种成型金刚石砂轮时,存在着修整尺寸和形状精度不高、达不到刀具成型磨削要求以及工具砂轮耗损量大等问题。通过对工具砂轮往返运动速度、进给量、耗损量及被修砂轮精度关系的试验研究,结合最佳转速比对金刚石砂轮进行修整,优化设计参数后有效解决了上述问题,效率提高30%。     

砂轮修整技术研究现状与展望

砂轮修整在高速高效磨削、精密超精密磨削、成形磨削过程中具有至关重要的作用。磨削过程中主要是砂轮与工件表面相互作用，砂轮随着磨削的进行逐渐磨钝难以有效磨削。为了保证磨削质量和精度，需对砂轮定期修整。砂轮修整自提出以来，国内外学者对其不断改进和创新，取得大量开创性和突破性研究成果，但日益提高的高精度、高效率、高性能生产要求对砂轮修整技术提出挑战。为了推动砂轮修整技术的不断进步，总结分析了目前修整方法的发展现状、基本原理、主要特点以及发展瓶颈，概述了砂轮修整亟需解决的问题，并对砂轮修整探究方向进行了展望。     

采用超硬砂轮修整机修整金刚石砂轮的试验研究

在采用自主研发的具有在线检测技术的超硬砂轮修整机修整各种成型金刚石砂轮时,存在着修整尺寸和形状精度不高、达不到刀具成型磨削要求以及工具砂轮耗损量大等问题.通过对工具砂轮往返运动速度、进给量、耗损量及被修砂轮精度关系的试验研究,结合最佳转速比对金刚石砂轮进行修整,优化设计参数后有效解决了上述问题,效率提高30％.     

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.     

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。     

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。     

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.     

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:     

Investigation on grinding temperature in ultrasonic vibration-assisted grinding of zirconia ceramics

The feasibility of ultrasonic vibration-assisted grinding (UVAG) in machining brittle materials, such as zirconia ceramics, has been preliminarily proved. The high temperature generated in grinding processes is a main factor responsible for thermal and surface/subsurface damage. However, there are few reports about grinding temperature for zirconia ceramics by UVAG. In this study, a grinding force model is used for the analysis of grinding temperature in UVAG based on kinematic principle of ultrasonic vibration and brittle material fracture removal mechanism. Then, the heat fluxes equation during grinding process is analyzed. And the grinding temperature model is developed based on theoretical grinding force model and heat fluxes. Finally, pilot experiments are carried out to analyze influence of vibration parameters and process parameters on UVAG temperature and verify the mathematical model. The comparison results show that ultrasonic vibration has an important influence on grinding temperature with the reduction of 10.6%. In addition, there is a good consistency between mathematical model and the experimental results. The average relative error is within 10%. Therefore, the mathematical model could be used to predict the UVAG temperature.     

磨削过程中磨削液的有效利用及其实现技术

在磨削加工过程中,一般都是利用向磨削区供给充分冷却液的方法来抑制零件表面温度升高和解决热损伤。但是由于砂轮的高速旋转,会在砂轮的表面形成一个高压空气边界层,阻止磨削液有效的进入磨削区,使加工条件恶化,磨削区温度升高,影响了工件的表面质量和完整性。通过合理的选择供液压力、流量和供液方式及喷嘴形式来提高进入磨削区有效磨削液的比例,进而更好的发挥磨削液的冷却作用,降低磨削区温度,保证工件表面质量和表面完整性,同时也有利于实现绿色磨削加工。     

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     

45钢高效深磨磨削力的实验研究

采用CBN砂轮,在砂轮线速度为90～210m/s的磨削条件下,对45钢进行了高效深磨实验.分析了不同工况对磨削力的影响.实验表明,在高效深磨过程中,提高砂轮线速度使磨削力减小,工件表面粗糙度值下降;增加磨削深度使磨削力上升、比磨削能下降、提高磨削效率,也能保证工件表面质量.     

A precision grinding method for screw rotors using CBN grinding wheel

Aiming at the high precision machining of screw rotors, a new grinding method for screw rotors using cubic boron nitride (CBN) grinding wheel is presented in this paper. Small electroplated CBN grinding wheel is firstly used to grind screw rotors. The mathematical model for the axial profiles of CBN grinding wheel is developed based on gear engagement theory. Taking the backlash of screw rotors and the coating thickness of CBN layer into consideration, the modification of the base body of the wheel shape is introduced into the design of the CBN grinding wheel. Wire cut electrical discharge machining low speed (WEDM-LS) was used to machine the base body of the CBN grinding wheel. The formed turning tools of the base body of CBN grinding wheel using WEDM-LS and the wheel shapes of CBN grinding wheel using the formed turning tool were performed. The CBN grinding wheels for the screw rotors were made to verify the validity and effectiveness of the presented method. The electroplated CBN grinding wheels were used to machine the screw rotors, and the machining experiments were performed. The data obtained in the experiments reach the fifth class of Chinese Standard GB10095-88.