Unit 6 Tooling for CNC,第6单元 机床的刀具系统,Reading Target,After reading this unit, you should be able to understand the three most important types of mechanisms storing and changing tools.,Text,6.1Tooling systems The machining center, a multifunction machine tool, uses a wide variety of cutting tools such as drills, taps, reamers, end mills, boring tools, etc., to perform various machining operations on a work piece. 6.1刀具系统 加工中心是一种多功能机床，可用钻头、丝锥、铰刀、端铣刀、镗刀等各种刀具对工件进行多种加工。,For these cutting tools to be inserted into the machine spindle quickly and accurately, all these tools must have the same taper shank tool holders to suit the machine spindle. The tool holder must also have a flange or collar, for the tool-changer arm to grab, and a stud, tapped hole, or some other device for holding the tool securely in the spindle by a power drawbar or other holding mechanism. 为了使这些刀具能迅速准确地插入机床主轴，所有刀具必须有相同的锥柄与机床主轴适配。刀柄还必须有凸沿和卡圈，以便换刀机械手夹持；还应有专用拉钉、螺孔或其他设备，通过电动拉杆或其他夹紧机构将刀具牢固夹紧在主轴上。,Text,So the way in which a range of cutting tools can be located and securely held in position is referred to as a tooling system. Once all the cutting tools are assembled and preset ,they are loaded into specific pocket locations in the machines tool-storage magazine where they are automatically selected as required by the part program. 因此，一组加工刀具被定位以及安全夹持在其位置上的方法被称作刀具系统。一旦所有刀具安装就绪，便可装入机床刀库的指定刀位，加工时可根据程序要求从刀库中自动选刀。,Text,6.2Automatic tool changer systems Many different types of mechanisms have been designed for storing and changing tools. The three most important are in the following: 6.2 自动换刀装置 用于存刀和换刀的机构有很多种，最主要的三种如下：,Text,6.2.1 Turret Head This type of system is found on older NC drilling machines. The tools are stored in the spindles of a device called a turret head. When a tool is called by the program, the turret rotates (indexes) it into position. 6.2.1 转塔式换刀装置 这种系统常见于老式NC钻床。刀具存放在一个称为转塔的主轴装置中。当程序调用某个刀具时，转塔就将其转到相应的位置上。,Text,The tool can be used immediately without having to be inserted into a spindle. Thus, turret head designs provide for very fast tool changes. The main disadvantage of turret head changers is the limit on the number of tool spindles that can be used. See Fig. 6-1. 刀具不必插入主轴即可立即启用，因此转塔式换刀装置的设计提供了快捷的换刀方式。它的主要缺点在于可用刀具数非常有限，见图6-1。,Text,Fig. 6-1 A turret head tool changing system 转塔式换刀装置,Text,6.2.2 Carousel Storage with Spindle Direct Tool Changer Systems of this type are usually found in vertical machining centers. Tools are stored in a coded drum called a carousel. 6.2.2主轴直接换刀的鼓轮式刀库 这种类型的系统常用于立式加工中心。刀具存放在被称为鼓轮式刀库的编码鼓轮上。,Text,The drum rotates to the space where the current tool is to be stored. It moves up and removes the current tool, then rotates the new tool into position and places it into the spindle. On larger systems the spindle moves to the carousel during a tool change. See Fig. 6-2. （换刀时，）鼓轮旋转到当前刀具的卸载位置，向上移动并卸下当前刀具；然后，旋转鼓轮把将要使用的刀具旋转到这个位置并将其安装在主轴上。在大型（刀库）系统中，换刀时采用轴向鼓轮移动的方式，见图6-2。,Text,Fig. 6-2 A carousel storage with spindle direct tool changer 主轴直接换刀的鼓轮式刀具,Text,6.2.3 Horizontal Storage Matrix Magazine with Pivot Insertion Tool Changer This type of system permits an operator to load many tools in a relatively small space. The chain may be located on the side or the top of the CNC machine. 6.2.3 换刀机械手取刀的水平矩阵刀库 这种系统可以在相当小的空间内装载很多刀具。链式矩阵刀库可以安装在CNC机床的侧面或者顶部。,Text,These positions enable tools to be stored away from the spindle and work. This will ensure a minimum of chip interference with the storage mechanism and a maximum of tool protection. 这种位置可使存放的刀具远离主轴和工件，从而最大限度地减少切屑对存刀装置的影响，同时更好地保护刀具。,Text,Upon entering a programmed tool change, the system advances to the proper tool via the chain mechanism. The pivot arm rotates and picks up both the new tool in the magazine and the old tool in the spindle. 当程序要求换刀时，刀具通过链式装置移动至适当的位置，换刀机械手旋转并同时从刀库抓起新刀和从主轴上抓起旧刀，接着，刀库前行至旧刀的存放位置，换刀机械手再次旋转并分别将新刀和旧刀插入主轴和刀库。,Text,A final rotation returns the arm back to its parked position. These steps are illustrated in Fig. 6-3. 最后机械手旋转返回到其停放位置。以上各步如图6-3所示。,Text,Upon entering a programmed tool change, the system advances to the proper tool via the chain mechanism. The pivot arm rotates and picks up both the new tool in the magazine and the old tool in the spindle. 当程序要求换刀时，刀具通过链式装置移动至适当的位置，换刀机械手旋转并同时从刀库抓起新刀和从主轴上抓起旧刀，接着，刀库前行至旧刀的存放位置，换刀机械手再次旋转并分别将新刀和旧刀插入主轴和刀库。,Text,Text,FIg. 6-3 A storage matrix magazine and pivot insert tool changer 换刀机械手取刀的矩阵刀库,Key Terms,tooling system 刀具系统 cutting tool 切削刀具 taper shank 锥柄 drill 钻头 tap丝锥 reamer 绞刀 end mill 端铣刀 boring tool 镗刀 stud 拉钉 tapped hole 螺孔,Key Terms,tool changer arm 换刀机械手 power drawbar 电动拉杆 holding mechanism夹紧机构 magazine 刀库 ATC Automatic Tool Changer 自动换刀装置 turret head tool changer转塔式换刀装置 drilling machine钻床 carousel storage with spindle direct changing主轴直接换刀的鼓轮式刀库,Key Terms,matrix magazine storage with pivot insertion tool changer 换刀机械手取刀的矩阵刀库 chain-type storage matrix magazine 链式矩阵刀库 vertical machining center 立式加工中心,