数控车床自动回转刀架结构设计【四工位立式回转刀架】
数控车床自动回转刀架结构设计【四工位立式回转刀架】,四工位立式回转刀架,数控车床自动回转刀架结构设计【四工位立式回转刀架】,数控车床,自动,回转,刀架,结构设计,四工位,立式
机电05-1班哈尔滨理工大学课程设计说明书设计题目:数控车床自动回转刀架结构设计班级:学号:姓名: 指导老师: 日期:2008.9.24设计任务题目:数控车床自动回转刀架结构设计任务:设计一台四工位立式回转刀架,适用于C616或C6132经济型数空车床。要求绘制自动回转刀架的机械结构图。推荐刀架所用电动机的额定功率为90W,额定转速1480r/min,换刀时要求刀架转动的速度为40r/min,减速装置的传动比为i=37。总体结构设计1、 减速传动机构的设计普通的三项异步电动机因转速太快,不能直接驱动刀架进行换刀,必须经过适当的减速。根据立式转位刀架的结构特点,采用蜗杆副减速时最佳选择。蜗杆副传动可以改变运动的方向,获得较大的传动比,保证传动精度和平稳性,并且具有自锁功能,还可以实现整个装置的小型化。2、 上刀体锁紧与精定位机构的设计由于刀具直接安装在上刀体上,所以上刀体要承受全部的切削力,其锁紧与定位的精度将直接影响工件的加工精度。本设计上刀体的锁进玉定位机构选用端面齿盘,将上刀体和下刀体的配合面加工成梯形端面齿。当刀架处于锁紧状态时,上下端面齿相互啮合,这时上刀体不能绕刀架的中心轴旋转;换刀时电动机正转,抬起机构使上刀体抬起,等上下端面齿脱开后,上刀体才可以绕刀架中心轴转动,完成转位动作。3、 刀架抬起机构的设计要想使上、下刀体的两个端面齿脱离,就必须设计适合的机构使上刀体抬起。本设计选用螺杆-螺母副,在上刀体内部加工出内螺纹,当电动机通过蜗杆-涡轮带动蜗杆绕中心轴转动时,作为螺母的上刀体要么转动,要么上下移动。当刀架处于锁紧状态时,上刀体与下刀体的端面齿相互啮合,因为这时上刀体不能与螺杆一起转动,所以螺杆的转动会使上刀体向上移动。当端面齿脱离啮合时,上刀体就与螺杆一起转动。设计螺杆时要求选择适当的螺距,以便当螺杆转动一定的角度时,使得上刀梯与下刀体的端面齿能够完全脱离啮合状态。下图为自动回转刀架的传动机构示意图,详细的装配图在一号图纸上。三、自动回转刀架的工作原理自动回转刀架的换刀流程如下图。图上表示自动回转刀架在换刀过程中有关销的位置。其中上部的圆柱销2和下部的反靠销6起着重要作用。当刀架处于锁紧状态时,两销的情况如图A所示,此时反靠销6落在圆盘7的十字槽内,上刀体4的端面齿和下刀体的端面齿处于啮合状态(上下端面齿在图中未画出)。需要换刀时,控制系统发出刀架转位信号,三项异步电动机正向旋转,通过蜗杆副带动蜗杆正向转动,与螺杆配合的上刀体4逐渐抬起,上刀体4与下刀体之间的端面齿慢慢脱开;与此同时,上盖圆盘1也随着螺杆正向转动(上盖圆盘1通过圆柱销与螺杆联接),当转过约时,上盖圆盘1直槽的另一端转到圆柱销2的正上方,由于弹簧3的作用,圆柱销2落入直槽内,于是上盖圆盘1就通过圆柱销2使得上刀体4转动起来(此时端面齿已完全脱开)。上盖圆盘1、圆柱销2以及上刀体4在正转的过程中,反靠销6能够从反靠圆盘7中十字槽的左侧斜坡滑出,而不影响上刀体4寻找刀位时的正向转动。上刀体4带动磁铁转到需要的刀位时,发信盘上对应的霍尔元件输出低电平信号,控制系统收到后,立即控制刀架电动机反转,上盖圆盘1通过圆柱销2带动上刀体4开始反转,反靠销6马上就会落入反靠圆盘7的十字槽内,至此,完成粗定位。此时,反靠销6从反靠圆盘7的十字槽内爬不上来,于是上刀体4停止转动,开始下降,而上盖圆盘1继续反转,其直槽的左侧斜坡将圆柱销2的头部压入上刀体4的销空内,之后,上盖圆盘1是下表面开始与圆柱销2的头部滑动。再次期间,上、下刀体的端面齿逐渐啮合,实现精定位,经过设定的延时时间后,刀架电动机停转,整个换刀过程结束。由于蜗杆副具有自锁功能,所以刀架可以稳定地工作。 蜗杆-涡轮减速 销连接上盖圆盘旋转螺杆正转刀架电动机正转 上刀体抬起 螺杆-螺母 端面齿错开 霍尔元件触发 上刀体旋转到位回答圆柱销落入上盖圆盘 蜗杆-涡轮减速 反靠销反靠端面齿啮合螺杆反转刀架电动机旋转上刀体下降,粗定位 精定位延时锁紧电动机停转 图:自动回转刀架的换刀流程主要传动部件的设计1. 蜗杆副的设计计算自动回转刀架的动力源是三相异步电动机。其中蜗杆与电动机直联,刀架转位时蜗轮与上刀体直联。已知电动机额定功率=90W。,额定转速=1480r/min,上刀体设计转速=40r/min,蜗杆副的传动比i=/=37。刀架从转位到锁紧时,需要蜗杆反向,工作载荷不均匀,启动时冲击较大,今要求蜗杆副的使用寿命=10000h。(1) 蜗杆的选型 GB/T10085-1988推荐采用渐开线蜗杆和锥面包络蜗杆。本设计采用结构简单,制造方便的渐开线型圆柱蜗杆。(2) 蜗杆副的材料 刀架中的蜗杆副传动的功率不大,但蜗杆转速干,一次,蜗杆的材料选用45钢,其螺旋齿面要淬火,硬度为4555HRC,以提高其表面耐磨行;蜗轮的转速较低,其材料主要考虑耐磨性,选用铸锡磷青铜ZCuSn10P1,采用金属模制造。(3) 按齿面接触疲劳强度进行设计 刀架中的蜗杆副采用闭式传动,多因齿面胶合或点蚀而失效。因此,进行载荷计算时,先按齿面接触疲劳强度进行设计,再按齿根弯曲疲劳强度进行校核。按蜗轮接触疲劳强度条件设计计算的公式 a (4-1)式中 a蜗杆副的传动中心距,单位mm; K载荷系数; 作用在涡轮上的转矩,单位N.mm; 弹性影响系数ZE; 许用接触应力,单位为MPa。从式4-1算出蜗杆副的中心距a之后,根据已知的传动比i=35,查表选择一个合适的中心距a值,以及相应的蜗杆,蜗轮参数。1) 确定作用在蜗轮上的转矩,设蜗杆头数=1,蜗杆副的传动效率=0.8,由电动机的额定功率=90W,可以算出蜗轮传动的功率=,再由蜗轮的转速=40r/min求得作用在蜗轮上的转矩=9.55=9.55=25.47Nm=22923Nmm2) 确定载荷系数K 载荷系数K= KA KB K。其中KA为使用系数,有表6-3查得, 由于工作载荷不均匀,启动时冲击较大,因此取KA=1.15; 为齿向分布系数,因工作载荷在启动和停止时有变化,故取KB=1.15; 为动载系数,由于转数不高。冲击不大,可取K=1.05。则载荷系数K=KA KB K 1.39使用系数工作类型IIIIII载荷性质均匀,无冲击不均匀,小冲击不均匀,大冲击每小时起动次数50起动载荷小较大大KA11.151.23) 确定弹性影响系数ZE,铸锡磷青铜蜗轮与钢蜗杆相配时,从有关手册查的弹性影响系数 ZE=160Mpa 1/2;4) 确定接触系数 先假设蜗杆分度圆直径d1 和传动中心距a的比值d1/a=0.35。查表的Zp=2.9铸锡青铜蜗轮的基本许用接触应力H(MPa)蜗轮材料铸造方法蜗杆螺旋面的硬度45HRC45HRC铸锡磷青铜ZCuSn10P1砂模铸造150180金属模铸造220268铸锡锌铅青铜ZCuSn5Pb5Zn5砂模铸造113135金属模铸造1281405)确定许用接触应力 根据蜗轮材料为铸锡磷青铜ZCuSn10P1金属模制造蜗杆螺旋齿面硬度大于45HRC可查表的蜗轮的基本许用应力=268MPa已知蜗杆为单头,蜗轮每转一转时每个轮齿啮合的次数j=1;蜗轮转数=40r/min;蜗杆副的使用寿命=10000h。则应力循环次数:N=60j n2 =2.4 10 7寿命系数: KHN =0.693许用接触应力: =KHN=186MPa6)计算中心距 将以上各参数带入4-1,求得中心距: a = 47.1 mm查表取a=63,已知蜗杆头数=1,设模数m=1.6mm,得蜗杆分度圆直径d1=28mm。这时d1/a=0.59,查表得接触系数=2.35。因为较大,所以上述计算结果可用。(4)蜗杆和涡轮的主要参数与几何尺寸 由蜗杆和涡轮的基本尺寸和主要参数,算的蜗杆和涡轮的主要几何尺寸后,即可绘制蜗杆副的工作图。 1)蜗杆的参数与尺寸 头数=1,模数m=1.6mm,轴向齿距=m=5.027mm轴向齿厚=0.5m=2.514mm,分度圆直径=28,直径系数q=17.5,分度圆导程角=。 取齿顶高系数=1,径向间隙系数=0.2,则齿顶圆直径=+2m=31.2mm,齿根圆直径=-2m(+)=24.314mm。 2)涡轮参数与尺寸 齿数=60,模数m=1.6mm,分度圆直径为=m=96mm,变位系数=a-()/2/m=0.6,涡轮喉圆直径为=+2m()=101.12mm,涡轮齿根圆直径=-2m(-+)=94.08mm,涡轮咽喉母圆半径=a-/2=12.44mm。(5)校核涡轮齿根弯曲疲劳强度 即检验下式是否成立: = 由蜗杆头数=1,传动比i=35,可以计算出涡轮齿数=i=35则涡轮的当量齿数: =35.17根据涡轮变位系数=0.6和当量齿数=35.17,查表的齿形系数=2.08螺旋角影响系数 =1-=0.977 根据涡轮的材料和制造方法,查表得涡轮基本许用弯曲应力: =56MPa 涡轮的寿命系数: =0.702 涡轮的许用弯曲应力: = =39.3MPa 将数据带入得: 可见, ,涡轮齿根的弯曲强度满足要求。蜗轮的基本许用弯曲应力(MPa)蜗轮材料铸造方法单侧工作双侧工作铸锡青铜ZCuSn10P1砂模铸造4029金属模铸造5640铸锡锌铅青铜ZCuSn5Pb5Zn5砂模铸造2622金属模铸造3226铸铝铁青铜ZCuAl10Fe3砂模铸造8057金属模铸造9064灰铸铁HT150砂模铸造4028HT200砂模铸造48342.螺杆的设计计算(1) 螺距的确定 刀架转位时,要求螺杆在转动约 的情况下,上刀体的端面齿与下刀体的端面齿完全脱离;在锁紧的时候,要求上下端面的啮合深度达2mm。因此,螺杆的螺距P应满足P2.4mm,今取螺杆的螺距P=6mm。(2) 确定其他参数 采用单头梯形螺杆,头数n=1,牙侧角= 150,外螺纹大径=50mm,牙顶间隙=0.5mm,基本牙型高度=0.5P=3mm,外螺纹牙高=3.5mm,外螺纹中径=47mm,外螺纹小径=43mm,螺杆螺纹部分长度H=50mm。(3) 自锁性能校核 螺杆-螺母材料均用45钢,查表取摩擦系数f=0.11;再求得梯形螺旋副的当量摩擦角: = 6.50而螺纹升角: = 2.33 小于当量摩擦角。因此满足自锁条件。编号无锡太湖学院毕业设计(论文)相关资料题目: 换刀机器人机械系统的设计 信机 系 机械工程及自动化专业学 号: 0923006 学生姓名: 王维维 指导教师: 过金超 (职称:副教授) (职称: )2013年5月25日目 录一、毕业设计(论文)开题报告二、毕业设计(论文)外文资料翻译及原文三、学生“毕业论文(论文)计划、进度、检查及落实表”四、实习鉴定表无锡太湖学院毕业设计(论文)开题报告题目: 换刀机器人机械系统的设计 信机 系 机械工程及自动化专业学 号: 0923006 学生姓名: 王维维 指导教师: 过金超 (职称:副教授) (职称: )2013年5月25日 课题来源 实验室课题。科学依据(包括课题的科学意义;国内外研究概况、水平和发展趋势;应用前景等)(1)课题的科学意义 当今的世界,制造业在经济发展中占有十分重要的地位,机械制造业更加是制造业中的支柱与核心。(2)国内外研究概况、水平和发展趋势从近几年世界上推出的机器人产品来看,工业机器人技术正在向智能化、模块化和系统化的方向发展。其发展趋势为:结构的模块化和可重构化;工作环境设计的优化和作业的柔性化,以及网络化和智能化等方面。:(3)应用现状及其前景目前工业机械手主要用于机床加工、铸造、热处理等方面,无论数量、品种和性能方面还是不能满足工业发展的需要。在国内主要是逐步扩大应用范围,重点发展铸造、热处理方面的机械手,以减轻劳动强度,改善作业条件,在应用专用机械手的同时,相应的发展通用机械手,有条件的还要研制示教式机械手、计算机控制机械手和组合机械手等。将机械手各运动构件,如伸缩、摆动、升降、横移、俯仰等机构以及根据不同类型的加紧机构,设计成典型的通用机构,所以便根据不同的作业要求选择不同类型的基加紧机构,即可组成不同用途的机械手。既便于设计制造,有便于更换工件,扩大应用范围。同时要提高速度,减少冲击,正确定位,以便更好的发挥机械手的作用。研究内容自动换刀机器人的机械系统,结构,机构,受力,驱动形式,传动系统。拟采取的研究方法、技术路线、实验方案及可行性分析(1)实验方案 通过对目前最常用的几种数控车床自动换刀系统的研究,对所研究的数控机床提出几个最为可行的工作系统,通过对方案的论证分析,选择最为理想的完成整个设计。对整个换刀装置,各组成机构,及各个自由度的实现进行分析。对换刀机械手的手指夹紧力进行分析,计算,对系统的关键部位进行校核,以确保换刀可靠性。对整个设计中涉及到的液压缸,计算确定其各个部分结构的具体尺寸,同时对活塞杆的强度,稳定性及螺栓的强度进行校核,以确保整个系统工作状态的准确可靠。(2)研究方法 选择最合理的换刀系统,通过比较,计算,设计出关键零件,结合前人的换刀系统设计出整个换刀装置,系统。研究计划及预期成果研究计划:2012年11月12日-2012年12月2日:教师下达毕业设计任务,学生初步阅读资料,完成毕业设计开题报告。2013年1月21日-2013年3月1日:指导毕业实习。2013年3月4日-2013年3月15日:确定总设计方案。2013年3月18日-2013年3月22日:总体设计(包括参数计算及结构分析计算)。2013年3月25日-2013年4月5日:总体设计(完成参数计算及结构分析计算后绘制草图:装配图)。2013年4月8日-2013年4月26日:零件设计。2013年4月29日-2013年5月20日:毕业论文说明书撰写和修改工作。预期成果:跟紧老师的脚步,认真的完成每一步设计,完善整个机械手的设计,熟悉掌握整个系统的原理。在学业将要完成之时,我将大幅提高我的机械研究能力,将会成为一名优秀的机械技术工作者。特色或创新之处快速,精确,大容量,的换刀系统。兼容随机刀具定位和固定刀具定位到位达到005mm。已具备的条件和尚需解决的问题 我已学习数控专业三年之久,掌握了一些这专业的部分知识,老师也给了一些参照资料,可以进行这方面的研究。 尚需解决的问题:(1)设计水平移动系统、垂直升降系统和末端操作器的驱动及传动系统;(2)设计水平移动系统、垂直升降系统和末端操作器的结构;(3)自动换刀机械手的升降机构的绘图(4)装卸刀手手臂和手部结构的设计指导教师意见 指导教师签名:年 月 日教研室(学科组、研究所)意见 教研室主任签名: 年 月 日系意见 主管领导签名: 年 月 日英文原文 On the NC lathe and tool changing systemCNC machine tool numerical control machine tools (Computer numerical control machine tools) abbreviation, is provided with a program control system of automatic machine tools. The logic control system can deal with the control code or other symbolic instruction specified program, and decoding the digital code, said information carrier, through the numerical control device input. After processing by CNC device control signals, control the machine movements, by drawing the shape and size requirements, will be automatically processed by the parts.Features: CNC machine tool operation and monitoring of all completed in the numerical control unit, it is the brain of CNC machine tools. Compared with the general machine tools, CNC machine tools has the following characteristics: the processing object adaptability, adapt to the characteristics of mold products such as a single production, provide the appropriate processing method for die and mould manufacturing; high machining accuracy, processing with stable quality; can coordinate linkage, processing complex shape parts; machining parts change, only need to change the program, can save the preparation time of production; the machine itself high precision, rigidity, can choose the amount of processing good, high productivity (typically 3 to 5 times that of ordinary machine tool);The machine is a high degree of automation, reducing labor intensity; conducive to the production management modernization. The use of CNC machine tools and the standard code of digital information processing, information transmission, the use of computer control method, has laid the foundation for the integration of computer aided design, manufacturing and management; on the operators of higher quality, higher demands for the repair of the technical staff; high reliability.Composition: CNC machine tools in general by the input medium, man-machine interactive equipment, CNC equipment, feed servo drive system, spindle servo drive system, the auxiliary control device, feedback apparatus and adaptive control device etc. 4 in NC machining, NC milling processing is the most complex, need to solve most problems. NC programming of NC line in addition to CNC milling, cutting, CNC EDM, CNC lathe, CNC grinding, each with its own characteristics, servo system is the role of the motion signal is converted into the machine moving parts from the numerical control device of pulse. Concrete has the following parts: the structure of CNC machine tools.Driver: he is driving parts of CNC machine tools, actuator, including spindle drive unit, feeding unit, spindle motor and feed motor. He through the electric or electro-hydraulic servo system to realize the spindle and feed drive under the control of numerical control device. When several feed linkage, can complete the positioning, processing line, plane curve and space curve.The main performance(1) the main dimensions.(2) the spindle system.(3) feed system.(4) tool system.(5) electrical. Including the main motor, servo motor specifications and power etc.(6) cooling system. Including the cooling capacity, cooling pump output.(7) dimensions. Expressed as length * width * height.Development trend of CNC lathe:High speed, precision, complex, intelligent and green is the general trend in the development of CNC machine tool technology, in recent years, made gratifying achievements in practicality and industrialization. Mainly in the:1 machine tool composite technology to further expand with the CNC machine tool technology, composite processing technology matures, including milling - car compound, car milling compound, car - boring - drill - gear cutting compound, composite grinding, forming, composite processing, precision and efficiency of machining is greatly improved. One machine is a processing factory, one card, complete processing concept is being accepted by more people, the development of compound processing machine tool is the trend of diversified.Intelligent technology 2 CNC machine tools have a new breakthrough, in the performance of NC system has been reflected more. Such as: automatically adjust the interference anti-collision function, after the power of workpiece automatically exit safety power-off protection function, machining parts detection and automatic compensation function of learning, high precision machining parts intelligent parameter selection function, process automatic elimination of machine vibration functions into the practical stage, intelligent upgrade the function of machine and quality.The 3 robots enable flexible combination of flexible combination of higher efficiency of robot and the host are widely used, make flexible line more flexible, extending the function, flexible line shorten further, more efficient. Robot and machining center, milling composite machine, grinder, gear processing machine tool, tool grinding machine, electric machine, sawing machine, punching machine, laser cutting machine, water cutting machine etc. various forms of flexible unit and flexible production line has already begun the application.4 precision machining technology has the machining precision of CNC metal cutting machine tools from the yarn in the original (0.01mm) up to micron level (0.001mm), some varieties has reached about 0.05 M. Micro cutting and grinding machining of ultra precision CNC machine tools, precision can reach about 0.05 m, shape precision can reach about 0.01 M. Special processing precision by using optical, electrical, chemical, energy can reach nanometer level (0.001 m). By optimizing the design of machine tool structure, machine tool parts of ultra precision machining and precision assembly, using high precision closed loop control and temperature, vibration and other dynamic error compensation technology, improve the geometric accuracy of machine tool processing, reduce the shape of error, surface roughness, and into the submicron, nano super finishing tiThe 5 functional component to improve the performance of functional components are at a high speed, high precision, high power and intelligent direction, and obtain the mature application. A full digital AC servo motor and drive device, high technology content of the electric spindle, linear motor, torque motor, linear motion components with high performance, application of high precision spindle unit and other function parts, greatly improving the technical level of CNC machine tools.The feed drive system of CNC lathe:Effect of feed drive system,The feed drive system of CNC machine tools will be received pulse command issued by the numerical control system, and the amplification and conversion machine movements carry the expected movement.Two, the feeding transmission system requirementsIn order to guarantee the machining accuracy of NC machine tool is high, the feed drive system of transmission accuracy, sensitivity high (fast response), stable work, high stiffness and friction and inertia small, service life, and can remove the transmission gap.Category three, feed drive system1, stepping motor servo systemGenerally used for NC machine tools.2, DC servo motor servo systemPower is stable, but because of the brush, the wear resulting in use need to change. Generally used for middle-grade CNC machine tools.3, AC servo motor servo systemThe application is extremely widespread, mainly used in high-end CNC machine tools.4, the linear motor servo systemNo intermediate transmission chain, high precision, the feed speed, no length limit; but the poor heat dissipation, protection requirements are particularly high, mainly used for high-speed machine.Driving component four, feed system1, the ball screw nut pairNC machining, the rotary motion into linear motion, so the use of screw nut transmission mechanism. NC machine tools are commonly used on the ball screw, as shown in Figure 1-25, it can be a sliding friction into rolling friction, meet the basic requirements of the feed system to reduce friction. The transmission side of high efficiency, small friction, and can eliminate the gap, no reverse air travel; but the manufacturing cost is high, can not lock, size is not too big, generally used for linear feed in small CNC machine tool.2, rotary tableIn order to expand the scope of the process of NC machine tools, CNC machine tools in addition to make linear feed along the X, Y, Z three coordinate axes, often also need a circumferential feed movement around Y or Z axis. Circular feed motion of CNC machine tools in general by the rotary table to realize, for machining center, rotary table has become an indispensable part of.Rotary table of commonly used CNC machine tools in the indexing table and NC rotary table.(1) indexing tableIndexing table can only finish dividing movement, not circular feed, it is in accordance with the instructions in the NC system, when indexing will work together with the workpiece rotation angle. When indexing can also use manual indexing. Provisions of indexing table is generally only rotary angle (such as 90, 60 and 45 degree).(2) NC rotary tableNC rotary table appearance similar to the indexing table, but the internal structure and function is not the same. The main function of the NC rotary table is based on the numerical control device sends command pulse signal, complete circumferential feed movement, various arc processing and surface processing, it can also be graduation work.3, guideRail is an important part of feed drive system, is one of the basic elements of the structure of machine tool, rigidity, precision and accuracy of NC machine tool which determines to a large extent retention. At present, guide the NC machine tool are sliding rail, rolling guideway and hydrostatic guideway.(1) sliding guideSliding guide rail has the advantages of simple structure, easy manufacture, good stiffness, vibration resistance and high performance, widely used in CNC machine tools, the use of most metal plastic form, known as the plastic guide rail, as shown in figure 1-26.On characteristics of the plastic sliding guide: friction characteristic is good, good wear resistance, stable movement, good manufacturability, low speed.(2) rolling guideRolling guide is placed in the rail surface between the ball, roller or needle roller, roller, the rolling friction instead of sliding surface of the guide rail between wipe.Rolling guide rail and the sliding rail, high sensitivity, small friction coefficient, and the dynamic, static friction coefficient is very small, so the motion is uniform, especially in the low speed movement, the stick-slip phenomenon is not easy to occur; high positioning accuracy, repeatability positioning accuracy is up to 0.2 m; traction force is small, wear small, portable in movement; good precision, long service life. But the vibration of rolling guide, high requirements on protection, complicated structure, difficult manufacture, high costAutomatic tool changer:One, the function of automatic tool changerAutomatic tool changing device can help save the auxiliary time of CNC machine tools, and meet in an installation completed procedure, step processing requirements.Two, on the requirement of automatic tool changerNumerical control machine tool for automatic tool changer requirement is: tool change quickly, time is short, high repetitive positioning accuracy, tool storage capacity is sufficient, small occupation space, stable and reliable work.Three, change the knife form1, rotary cutter replacementIts structure is similar to the ordinary lathe turret saddle, according to the processing of different objects can be designed into square or six angle form, consists of the NC system sends out the instruction to the rotary cutter.2, the replacement of the spindle head tool changeThe spindle head pre-loaded required tools, in order to machining position, the main motor is switched on, drives the cutter to rotate. The advantage of this method is that eliminates the need for automatic clamping, cutting tool, clamping and cutting tool moving and a series of complex operation, reduce tool change time, improve the reliability of the tool change.3, the use of changing toolThe processing required tools are respectively arranged in the standard tool, adjust the size of the machine after certain way add to the knife, the exchange device from the knife and the spindle take knife switch.Four, the tool switching deviceAutomatic tool change device, device for knife library and the main shaft transmission and handling tool for tool exchange device. Tool exchange often have two kinds: mechanical hand tool exchange and by relative motion of knife and machine tool spindle exchange tool (cutter to the spindle tool change or movement of the spindle to the knife knife tool change position), the mechanical hand tool change is most common.Five, the knifeThe knife is one of the most important parts in automatic tool changer, have great influence on the overall design of NC machine tool and its capacity, layout and structure.1, the capacity of the tool storageA number of knife inventory cutters, generally depending on the processing requirements. The capacity of small knife, can not meet the processing needs; capacity is too large, will make the knife database size, covers an area of large, tool selection process for a long time, and the knife library utilization rate is low, the structure is too complex, causing great waste. 2, the knife typeGenerally, the chain disc and drum type knife several.Disc cutter tool was circular arrangement, low utilization of space, size is not large but simple structure.Chain magazine compact structure, large capacity, link shape can also be random bed made of various forms and flexible layout, but also will change the cutter location prominent for tool change, widely used.Drum type or lattice type knife, covers an area of small, compact structure, large capacity, but cutter selection, tool movements are complicated, for centralized knife system for FMS.3, tool selectionOften order tool selection and random selection tool two.The order of tool selection is before processing, the processing required tools to process sequence of insert knife knife, order not wrong, processing adjust knife in order. The work piece changes, the need to reset the tool sequence, the operation is simple, and the processing tool with a workpiece can not be repeated use.A knife is the cutting tool has its own code, optional and can be repeatedly used in processing, also do not put in the fixed knife, knife, the knife is convenient.Technology file is the guiding file workers during processing, process scheme is reasonable, not only affect the efficiency of NC machining, and will directly affect the machining quality. Therefore, before NC programming, NC machining process follows the process of certain principles and combined with the characteristics of CNC lathe seriously and develop in detail the good parts.In the CNC lathe processing parts, should according to the principle of dividing process concentrated, in a fixture as far as possible to complete the most or even all of the surface processing. Part positioning, according to the structure of different shapes, usually cylindrical, face or end clamping, and strive to design basis, process reference and programming the unification datum.The main contents are: analysis of NC machining technology of part drawings, clear processing content; determination method, workpiece on lathe the surface processing sequence and tool feed line and cutting tools, fixtures and cutting the amount of choice.Analysis, part drawing processIn the machining process planning of parts, first of all to carry on in-depth analysis to the processing object. For NC turning process should consider the following aspects:1 reading part drawing, analysis of geometric conditions of part contourIn turning process of manual programming, to calculate each node coordinates; in automatic programming, to define the components outline all geometric elements. Therefore, in the analysis of parts should pay attention to:Parts of the map is missing a dimension, the geometric conditions are not sufficient to constitute the part outline, influence;Map location map parts of the ambiguity or dimension is not clear, so that the program cant start;The part drawing geometry given is not reasonable, resulting in mathematical difficulties.The part drawing dimensioning methods should adapt to the characteristics of CNC lathe processing, should size or directly given coordinate dimension with the same standard.2 dimensional accuracy requirementsAnalysis of the pattern of parts size precision requirements, to determine whether achieve the turning process, and determine the process method to control the dimension precision. In the analysis process, but also can convert some dimensions such as size, incremental and absolute size and dimension chain calculation. In the use of NC lathe turning parts, average value of components often required size and maximum and minimum limit of size size as the basis of programming.3 shape and position accuracy requirementsPattern of parts tolerance of shape and lo
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