【作者】 王德智；

【导师】 张弘弢；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2008， 硕士

【摘要】 要实现高速切削、干切削、硬态切削、精密和超精密切削,刀具材料是关键。超硬刀具以其独特的性能为上述切削技术的实现提供了最基本的前提条件,在现代加工技术中的地位和作用越来越重要。对超硬刀具的刃磨技术以及刃磨设备的研究,业已受到了人们的极大关注。超硬刀具材料的硬度大、耐磨性好,是现代切削加工中的理想刀具材料,但是与此同时也给超硬刀具的刃磨带来了极大的困难。目前生产实践中对超硬刀具的刃磨多采用进口磨床,如RS-12、FC-200D型PCD&PCBN专用刀具磨床等。这样的磨床刚度好,加工精度高,但进口设备价格昂贵,加工成本较高,中小企业难以承受。针对这种情况,本课题尝试在价格较便宜的普通工具磨床上刃磨超硬刀具。但是大多数工具磨床的工作台不具备自动往复运动的能力,或者即使有液压往复系统,由于液压往复运动的特性,也无法满足超硬刀具的刃磨要求。为了解决这个问题,本课题对普通工具磨床进行了数控改造,使磨床的工作台能够实现自动往复运动。本论文从机械设计、控制系统和刃磨试验三个部分介绍了磨床的数控改造。机械设计部分,设计了一个具有离合结构的传动系统,可以使控制系统和磨床的工作台之间进行结合和分离。控制系统部分,以AT89S52单片机为核心,采用步进电机为驱动元件,液晶显示器和矩阵键盘为人机界面,组成了一个开环控制系统。该系统的软件部分,以离散法对步进电机的升降速过程进行了处理,并用C语言编程实现了控制系统对磨床工作台自动往复运行的速度和行程的控制。刃磨试验部分,在经过数控改造后的普通工具磨床上实现了超硬刀具的刃磨,通过SEM扫描电镜观察,发现刀具刃口质量良好,达到精密加工的要求。证明改造后的磨床运行平稳,振动小,能够满足超硬刀具的刃磨要求,达到了改造的目的。更多还原

【Abstract】 Super-hard cutting tools, with their unique properties, are playing a more and more important role in modern processing technology. Since cutting tool material is a key factor in realizing high-speed, dry and hard-state cutting, especially when high precision or ultra-high precision cutting is needed, increasing attention is paid to the investigation of super-hard cutting tool manufacturing and grinding equipments.With their excellent combination of high hardness and good wear resistance, super-hard cutting tools are the ideal ones for modern machining. However, all these favorable properties also contribute to their extremely poor machinability. Currently exported grinding machines such as RS-12 and FC-200D are usually used to grind super-hard cutting tools. These kinds of machine hold high rigidity and good precision, but due to their high prices, moderate and small enterprises can not afford generally. In light of this issue, this study tries to realize super-hard cutting tools grinding using a general tool grinder, which is fairly cheap. But most tool grinders can’t satisfy the strict qualifications needed to grind super-hard cutting tools either because of the inherent drawbacks of their hydraulic mechanisms, or because that they can’t realize auto-reciprocating. In order to solve this problem, a general tool grinder was modified, and the function of auto-reciprocating was achieved.The modification of a general grinding machine was introduced in this paper as the following three parts: mechanical design, control system and grinding experiment. Firstly, a connecting mechanism between the control system and the work table of tool grinder was designed. Secondly, an AT89S52 microcontroller was used as the core to form an open-loop control system, in which a stepper motor was employed as the actuator and a LCD and a keyboard were used as the interface. As to the software of the system, a discrete control method for accelerating and decelerating process of stepper motor was introduced, and the speed and position of the work table were controlled through C language program. Finally, a series of grinding experiments were conducted on the post-modified grinding machine. By means of SEM micrograph analysis, it was found that high quality cutting edge can be achieved using this post-modified grinding machine. It shows that the modified general grinding machine can run smoothly with very small vibration, and it can satisfy all the specific qualifications needed for super-hard cutting tools manufacturing.更多还原