基于单片机的超硬刀具刃磨设备的数控改造
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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。
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.
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。
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.
引文
[1]于启勋.金属切削加工技术的发展概况.工具市场与管理,1986(7):44-47.
[2]于启勋.超硬刀具材料的发展和应用.工具技术,2004,38(1):9-11.
[3]I.E.Clark,P.K.Sen.Advances in the development of ultrahard cutting tool materials.Industrial Diamond Review,1998(2):40-44.
[4]Stephan Zwahlen.Constant innovations demanded by the PCD tooling market.Industrial Diamond Review,2004(3):32.
[5]Paul Butler.The economics of rapid grinding of PCD and PCBN cutting tools.Industrial Diamond Review,2003(1):20-23.
[6]冯克利.PCBN切削刀片的性能及合理使用.工艺装配,2000,38(433):39-41.
[7]J.H.Dailey.PCBN tools take off on hard surface.American Mchaist,1996:39-41.
[8]刘献礼,文东辉,候世香等.硬态干切削机理及技术研究综述.中国机械工程,2001,13(11):973-976.
[9]严复钢,崔宁,王剑,袁巧玲等.CBN刀具硬态切削过程中金属软化效应的研究.哈尔滨理工大学学报,2003,8(3):52-58.
[10]P.J.Heath.Structure,properties and applications of polycrystalline cubic boron nitride,in:Proceedings of the 14th North American Manufacturing Research Conference,Minneapolis,MN,USA,1986,pp.66-80.
[11]A.M.Abrao,D.K.Aspinwall,M.L.H.Wise.A review of polycrystalline cubic boron nitride cutting tool developments and application,in:Proceedings of the 13th International MATADOR Conference,Manchester,UK,1993,pp.169-180.
[12]刘献礼,李振加等.PCBN刀具的制造.机械工艺师,1998(4):27-28.
[13]W.Konig,A.Neises.Wear mechanisms of ultrahard,non-metallic cutting materials.Wear,162-164(1993):12-21.
[14]S.Gimenez,O.Vander Blest,J.Vleugels.The role of chemical wear in machining iron based materials by PCB and PCBN super-hard tool materials.Diamond & Related Materials,2006.
[15]Peter J.Heath.Developments in applications of PCD tooling.Journal of material technology,2001(116):31-38.
[16]寇自力.超硬刀具的发展与应用.工具技术,2004,34(4):45-47.
[17]谢光亮.发展我国经济型数控机床.制造技术与机床,1994(2):40-41.
[18]孙淑婷,杨旺利.经济型数控机床发展探讨.科技情报开发与经济,1997(1):19-21.
[19]王玉琳.发展经济型数控系统的必要性.机床与液压,2006(10):231-232.
[20]陈远龄.机床电气自动控制.重庆:重庆大学出版社,2006.
[21]濮良贵,纪名刚.机械设计.北京:高等教育出版社,2003.
[22]洪慎海.铜合金拔叉液态模锻工艺及模具设计.模具技术,1999(6):64-68.
[23]朱学斌.B5032插床离合器的改造.铁道机车车辆工人,2001(3):7-9.
[24]章烈剽.基于单片机的高精度步进电机控制研究:(硕士学位论文).武汉:武汉理工大学,2007.
[25]吴小平.基于DSP的电动机控制系统及两相混合式步进电机驱动器的设计:(硕士学位论文).沈阳:沈阳工业大学,2005.
[26]B.Robert,F.Alin,C.Goeldel.Aperiodic and dynamics in hybrid step motor-new experimental results.Industrial Electronics,2001.Proceedings.ISIE 2001.IEEE International Symposium on.June 2001:2136-2141.
[27]Chen D,Yung KL,Cheng KW.Enhangcing Low-speed Performance of Hybrid Stepping Motor Servo by Ripple Canceling Technique.Proc of IEEE Conference on Electric Machines and Drivers,HongKong,1999:147-149.
[28]李爱芹.基于DSP的三相混合式步进电机细分驱动系统研究:(硕士学位论文).杭州:浙江工业大学,2007.
[29]陈维山,赵杰.机电系统计算机控制.哈尔滨:哈尔滨工业大学出版社,1999.
[30]王鸿钰.步进电机控制技术入门.上海:同济大学出版社,1990.
[31]海老原大树.电动机技术实用手册.王益全,刘军,秦晓平等译.北京:科学出版社,2006.
[32]邵建华,陈清运,刘鹊然.MQ6025A轻型万能工具磨床的数控改造.机械研究与应用,2004,17(1):38-40.
[33]R.Bruce Kieburtz.The Step Motor-The Next Advance in Control Systems.IEEE Trans On Automatic Control,1964,9(1):98-104.
[34]J.Reiss,F.Alin,M.Sandler,etc.A detailed analysis of the nonlinear dynamics of the electic step motor.Industrial Technology,2002.IEEE ICIT' 02.2002 IEEE International Confercence on.Dec.2002:1078-1083.
[35]霍迎辉,陈宇翔.步进电机的微机和单片机控制.电机技术,2005(1):8-10.
[36]F.Fadul et al.A Single MSI Programmable Chip Controller for Stepper Motors.Computer in Industry,22Nov,1993:207-211.
[37]F.Fadul et al.Low-Cost MSI Controller for Stepper Motors.Computer in Industry,17Nov,1991:63-66.
[38]Chen D,Paden B.Nonlinear Adaptive Torque-Ripple Cancellation for Step Motors.Proc of IEEE Conference on Decision and Control,Hawaii,USA,1990,38(6):3319-3324.
[39]李海波,何雪涛.步进电机升降速的离散控制.北京化工大学学报,2003,30(1):92-94.
[40]李仁定.电机的微机控制北京:机械工业出版社,1999.
[41]肖云聪.基于单片机的单晶金刚石刀具刃磨设备的数控改造:(硕士学位论文).大连:大连理工大学,2006.
[42]朱宇光.单片机应用新技术教程.北京:电子工业出版社,2000.
[43]李海波.单片机对步进电机三相六拍指数规律升降速的并行控制:(硕士学位论文).北京:北京化工大学,2003.
[44]许永华,李刚,陈科等.8098单片机对步进电机的升降速控制.机械与电子,1995(6):12-13.
[45]张建民.机电一体化系统设计.北京:北京理工大学出版社,1996.
[46]杨连文.超硬刀具精密刃磨的特点.工具技术,1996,30(5):13.
[47]刘志强.PCD刀具的金刚石砂轮机械刃磨工艺.工具技术,2006,40(9):62-64.
[48]张启彬,李嫂,李德亨等.聚晶金刚石刀具的刃磨机理.工具技术,1998,32(5):7-11.
[49]G Werner,M Renter.Grindability of PCD.Industrial Diamond Review,1989(1):15-19.
[50]刘峰斌,李嫂,张弘弢.聚晶金刚石刀具的刃磨工艺.工具技术,2001,35(11):3-5.
[2]于启勋.超硬刀具材料的发展和应用.工具技术,2004,38(1):9-11.
[3]I.E.Clark,P.K.Sen.Advances in the development of ultrahard cutting tool materials.Industrial Diamond Review,1998(2):40-44.
[4]Stephan Zwahlen.Constant innovations demanded by the PCD tooling market.Industrial Diamond Review,2004(3):32.
[5]Paul Butler.The economics of rapid grinding of PCD and PCBN cutting tools.Industrial Diamond Review,2003(1):20-23.
[6]冯克利.PCBN切削刀片的性能及合理使用.工艺装配,2000,38(433):39-41.
[7]J.H.Dailey.PCBN tools take off on hard surface.American Mchaist,1996:39-41.
[8]刘献礼,文东辉,候世香等.硬态干切削机理及技术研究综述.中国机械工程,2001,13(11):973-976.
[9]严复钢,崔宁,王剑,袁巧玲等.CBN刀具硬态切削过程中金属软化效应的研究.哈尔滨理工大学学报,2003,8(3):52-58.
[10]P.J.Heath.Structure,properties and applications of polycrystalline cubic boron nitride,in:Proceedings of the 14th North American Manufacturing Research Conference,Minneapolis,MN,USA,1986,pp.66-80.
[11]A.M.Abrao,D.K.Aspinwall,M.L.H.Wise.A review of polycrystalline cubic boron nitride cutting tool developments and application,in:Proceedings of the 13th International MATADOR Conference,Manchester,UK,1993,pp.169-180.
[12]刘献礼,李振加等.PCBN刀具的制造.机械工艺师,1998(4):27-28.
[13]W.Konig,A.Neises.Wear mechanisms of ultrahard,non-metallic cutting materials.Wear,162-164(1993):12-21.
[14]S.Gimenez,O.Vander Blest,J.Vleugels.The role of chemical wear in machining iron based materials by PCB and PCBN super-hard tool materials.Diamond & Related Materials,2006.
[15]Peter J.Heath.Developments in applications of PCD tooling.Journal of material technology,2001(116):31-38.
[16]寇自力.超硬刀具的发展与应用.工具技术,2004,34(4):45-47.
[17]谢光亮.发展我国经济型数控机床.制造技术与机床,1994(2):40-41.
[18]孙淑婷,杨旺利.经济型数控机床发展探讨.科技情报开发与经济,1997(1):19-21.
[19]王玉琳.发展经济型数控系统的必要性.机床与液压,2006(10):231-232.
[20]陈远龄.机床电气自动控制.重庆:重庆大学出版社,2006.
[21]濮良贵,纪名刚.机械设计.北京:高等教育出版社,2003.
[22]洪慎海.铜合金拔叉液态模锻工艺及模具设计.模具技术,1999(6):64-68.
[23]朱学斌.B5032插床离合器的改造.铁道机车车辆工人,2001(3):7-9.
[24]章烈剽.基于单片机的高精度步进电机控制研究:(硕士学位论文).武汉:武汉理工大学,2007.
[25]吴小平.基于DSP的电动机控制系统及两相混合式步进电机驱动器的设计:(硕士学位论文).沈阳:沈阳工业大学,2005.
[26]B.Robert,F.Alin,C.Goeldel.Aperiodic and dynamics in hybrid step motor-new experimental results.Industrial Electronics,2001.Proceedings.ISIE 2001.IEEE International Symposium on.June 2001:2136-2141.
[27]Chen D,Yung KL,Cheng KW.Enhangcing Low-speed Performance of Hybrid Stepping Motor Servo by Ripple Canceling Technique.Proc of IEEE Conference on Electric Machines and Drivers,HongKong,1999:147-149.
[28]李爱芹.基于DSP的三相混合式步进电机细分驱动系统研究:(硕士学位论文).杭州:浙江工业大学,2007.
[29]陈维山,赵杰.机电系统计算机控制.哈尔滨:哈尔滨工业大学出版社,1999.
[30]王鸿钰.步进电机控制技术入门.上海:同济大学出版社,1990.
[31]海老原大树.电动机技术实用手册.王益全,刘军,秦晓平等译.北京:科学出版社,2006.
[32]邵建华,陈清运,刘鹊然.MQ6025A轻型万能工具磨床的数控改造.机械研究与应用,2004,17(1):38-40.
[33]R.Bruce Kieburtz.The Step Motor-The Next Advance in Control Systems.IEEE Trans On Automatic Control,1964,9(1):98-104.
[34]J.Reiss,F.Alin,M.Sandler,etc.A detailed analysis of the nonlinear dynamics of the electic step motor.Industrial Technology,2002.IEEE ICIT' 02.2002 IEEE International Confercence on.Dec.2002:1078-1083.
[35]霍迎辉,陈宇翔.步进电机的微机和单片机控制.电机技术,2005(1):8-10.
[36]F.Fadul et al.A Single MSI Programmable Chip Controller for Stepper Motors.Computer in Industry,22Nov,1993:207-211.
[37]F.Fadul et al.Low-Cost MSI Controller for Stepper Motors.Computer in Industry,17Nov,1991:63-66.
[38]Chen D,Paden B.Nonlinear Adaptive Torque-Ripple Cancellation for Step Motors.Proc of IEEE Conference on Decision and Control,Hawaii,USA,1990,38(6):3319-3324.
[39]李海波,何雪涛.步进电机升降速的离散控制.北京化工大学学报,2003,30(1):92-94.
[40]李仁定.电机的微机控制北京:机械工业出版社,1999.
[41]肖云聪.基于单片机的单晶金刚石刀具刃磨设备的数控改造:(硕士学位论文).大连:大连理工大学,2006.
[42]朱宇光.单片机应用新技术教程.北京:电子工业出版社,2000.
[43]李海波.单片机对步进电机三相六拍指数规律升降速的并行控制:(硕士学位论文).北京:北京化工大学,2003.
[44]许永华,李刚,陈科等.8098单片机对步进电机的升降速控制.机械与电子,1995(6):12-13.
[45]张建民.机电一体化系统设计.北京:北京理工大学出版社,1996.
[46]杨连文.超硬刀具精密刃磨的特点.工具技术,1996,30(5):13.
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