英语原文：
Design Of Tool Machine Prop
Research significance
The original knife machine control procedures are designed individually, not used tool management system, features a single comparison, the knife only has to find the tool knife, knife positioning the shortest path, axis tool change, but does not support large-scale tool.
Automatic knife in the knife election, in the computer memory knife-election on the basis of using the Siemens 840 D features, and the election procedures knife more concise, and complete the space Daotao View. ATC use the knife rapid completion of STEP-7 programming, and have been tested in practice. In the positioning of the knife, PLC controlled modular design method, which future production of similar machines will be very beneficial, it is easy to use its other machine. Automatic tool change systems will be faster growth, reduced tool change time, increase the positioning accuracy tool is an important means to help NC technology development.
Tool and inventory components of modern production is an important link in the management, especially for large workshop management. The traditional way of account management, and low efficiency, high error rate, and not sharing information and data, tools and the use of state can not track the life cycle, are unable to meet the current information management needs. With actual production, we have to establish a workshop tool for the three-dimensional tool storage system to meet the knife workshop with auxiliary storage and management needs.
The system uses optimization technology, a large number of computer storage inventory information, timely, accurate, and comprehensive tool to reflect the inventory situation. The entire system uses a graphical interface, man-machine dialogue tips from the Chinese menu, select various functions can be realized and the importation of all kinds of information. Management system using online help function. Through the workshop management, network management and sharing of information. Have automated inventory management, warehousing management tool, a tool for the management and statistical functions.
1.System components and control structure
The entire system, including the structure and electrical machinery control systems.
1.1.1Mechanical structure and working principle
Tool from the stent, drive, drive system, Turret, shielding, control system, and electrical components. Support from the column, beam, the upper and lower guide Central track, and track support component.
1) Drive for the system chosen VVVF method. Cone used brake motors, with VVVF by Cycloid
reducer through sprocket drive.
2) Drag a variable frequency drive system and control technology. VVVF adopted, will speed drive shaft in the normal range adjustment to control the speed rotary turret to 5 ~ 30mm in, the drive shaft into two, two under through sprocket, the two profiled rollers Chain driven rotating shelves. Expansion chain adopted by the thread tight regulation swelling, swelling the regular way. - Conditioned, under the same chain-of-conditioning, so that the chain of uniform.
3) Turret and shields the entire total of 14 independent Turret. 13 of them as a socket-Turret, as a drawer-Turret, each Turret back through the pin and, under the conveyor chain link chain plate, installed at the bottom roller, chain driven rotating turret rotation along the track. Outlet-Turret and BT50-BT40 Turret Turret two kinds of forms. To strengthen management, security, landscaping modeling, shelf peripherals and shields. Turret-drawer drawer placed at six other Des V oeux a knife, can be categorized with some of knife auxiliary equipment, such as bits, such as turning tools.
1.1.
2.Electrical Control System
This tool storage systems is the main electrical control their shelves for operational control and position control. Operational control equipment, including operation of the start of braking control. Position Control is the main location and address of the shelves for testing. Control system as shown in Figure 1.
图 1 Tool Control System
1) Electric Transmission horizontal rotary tool storage systems are the mechanical movements are repeated short-term work system. And the run-time system needs some speed, speed transmission needs, the system will use VVVF method can be used simple structure, reliable operation of the motor and frequency inverter.
2) Control of the system is divided into two kinds of manual control and automatic control, manual control as a general reserve and debugging methods of work; ways to the system control computer (IPC) and the control unit (inverter contactor , etc.) consisting of a control system.
3) location and positioning accuracy of the system automatically identify the site and location using a detection device as proximity switches, relays through the plate-point isolation and the number plate recorded close to the switching signal acquisition and operation of Hutchison with a Optimal Path addressable identify the current location and shelves of the purpose of the shelf location. In order to enable a more accurate positioning system, adopted two photoelectric switches, to detect the two shelves of the two films.
1.2.The functions of the knife
knife The is the role of reserves a certain number of tools, machine tool spindle in hand to achieve the fungibility a disc cutter knife is the type of library, the chain knives, and other means, in the form of the knife and capacity according to the Machine Tool to determine the scope of the process.
https://www.doczj.com/doc/e113955957.html,mon types
The knife is a tool storage devices, the common knife mainly in the following forms:
(1) the turret knife
Including the first level turret vertical turret and the first two, see Figure 2.6 a) and b):
(2) the disc cutter
Disc knife in the library with discoid knife, cutting tool along See how vertical arrangement (including radial and axial from knife from knife), along See how radial array into acute or arranged in the form of the knife. Simple, compact, more applications, but are ring-cutter, low utilization of space. Figure 2.7 a) to c). If the knife storage capacity must be increased to increase the diameter of the knife, then the moment of inertia also increased correspondingly, the election campaign long knife. Tool number not more than 32 general. Cutter was multi-loop order of the space utilization knife, but inevitably given the knife from complex institutions,
applicable to the restricted space Machine Tool storage capacity and more occasions. Two-disc structure is two smaller capacity knife on both sides of the sub-spindle place, more compact
layout, the number of certificates corresponding increase knife, apply to small and medium-sized processing center.
(3) the chain knife
Including single-and multi-ring chain ring chain, chain link can take many forms change, see Figure 2.8 a) to c), the basic structure shown in
Figure 2. 8 do
Features: knife apply to
the larger capacity of the
occasion, the space of the
small number of
generally applicable to
the tool in the 30-120.
Only increase the length
of the chain tool will increase the number should not be increased circumferential speed of its
moment of inertia of the knife does not increase the disc as large.
(4) linear combination knife and the knife library
The linear knife simple structure in Figure 2.9, tool single order, the capacity of small knife, used for CNC lathe and drill press on. Because the location of fixed knife, ATC completed action by the spindle without manipulator. The cutter knife is generally the turret combination turret with a combination of the disc cutter knife and the chain combination. Every single knife the knife certificates of smaller, faster tool change. There are also some intensive drum wheel, and the lattice-type magazine for the knife, the knife-intensive though. Small footprint, but because of structural constraints, basically not used for single processing center, the concentration used for FMS for the knife system.
1.4 Tool storage capacity
Tool storage capacity of the first to consider the needs of processing, from the use of point of view, generally 10 to 40 knives, knife will be the utilization of the high, and the structure is
compact.
1.5 Tool options
(1) choose to order processing tool according to the order, followed Add to the knife every knife in the Block. Each tool change, the order of rotation of a cutter knife on location, and remove the need knives, has been used by the cutter knife can be returned to the original Block, can also order Add Block, a knife. However, as the knife in the tool in different processes can not be repeated use of the knife must increase the capacity and lower utilization rate.
(2) most of the arbitrary choice of the current system of using arbitrary NC election knives, divided into Daotao coding, coding and memory-cutter, three. Daotao coding tool code or knives or Daotao need to install the code used to identify, in accordance with the general principle of binary coding coding. Tool knife election coding method uses a special knife handle structure, and each of the coding tool. Each of the tool has its own code, thereby cutting tool can be in different processes repeatedly used, not to replace the tool back at the original knife, the knife capacity can be reduced accordingly. Memory-election this paper knife, in this way can knives and knife in the position corresponding to the Daotao memory of the PLC in the NC system, no matter which tool on the Inner knife, tool information is always there in mind, PLC . On the knife with position detection devices, will be the location of each Daotao. This tool can be removed and sent back to arbitrary. On the knife is also a mechanical origin, every election, the nearest knife selection.
1.6.Control of the knife
(1) the knife as a system to control the positioning axis. In the ladder diagram in accordance with the instructions for computing T code comparison of the output angle and speed of instructions to the knife the knife servo drive servo motor. Tool storage capacity, rotation speed, and / deceleration time, and other system parameters can be set in such a manner free from any outside influence positioning accurate and reliable but the cost is higher.
(2) knife from the hydraulic motor drives, fast / slow the points, with proximity switches count and positioning. In comparison ladder diagram of the current storage system knife (knife spindle) and goals knife (pre-knife) and computing, then output rotation instructions, judging by the shortest path rotation in place. This approach requires sufficient hydraulic power and electromagnetic valve knife the rotational speed can be adjusted through the throttle. But over time may be oily hydraulic, oil temperature and environmental factors impact the change in velocity and accuracy. Not generally used in large and medium-sized machine tool change frequently.
(3) the knife from AC asynchronous motor driven cam mechanism (Markov institutions), with proximity switches count, which means stable operation, and generally accurate and reliable
positioning cam used in conjunction with a mechanical hand, ATC fast-positioning.
2. ATC, the main types, characteristics, and the scope of application 2.1 Auto Rotary Tool
Rotary Tool automatically on
the use of CNC machine tool is a
simple installation of automatic tool
change, the Quartet and 47.60 Turret
Tool various forms, such as rotary
turret were installed on four, six or
more of the Tool , NC instructions by
ATC. Rotary Tool has two vertical
and horizontal, relatively simple
structure, applicable to economic
CNC lathe.
Rotary Tool in the structure must
have good strength and stiffness,
resistance to bear rough Cutting Tool
in the cutting force and reduce the
role of deformation and improve
processing accuracy. Rotating Tool
to choose reliable positioning
programme structure and reasonable position, in order to ensure that each rotary turret to a higher position after repeated positioning accuracy (typically 0.001 to 0.005mm). Figure 2.1 shows the spiral movements of the Quartet Turret.
Auto Rotary Tool in the simplest of ATC, is 180 o rotary ATC devices, as shown in Figure 2.2 ATC instructions received, the machine control system put ATC spindle control to the designated location at the same time, the tool movement to the appropriate location, ATC, with the rotary axis and at the same time, the knives matching tool; drawbars from Spindle Cutting Tools rip, ATC, will be the tool from their position removed; ATC, 180 o rotary tool spindle and the tool and tool away; ATC, the Rotary At the same time, the tool refocusing its position to accept Spindle removed from the cutting tool; Next, ATC, will be replaced with the cutter knives were unloaded into the spindle and tool: Finally, back to the original ATC, "standby" position. At this point, ATC completed procedures to continue to run. This ATC, the main advantage of
simple structure, the less movement, fast tool change. The main disadvantage is that knives must be kept in parallel with the axis of the plane, and after the home side compared to the tool, chip and liquid-cutting knife into the folder, it is necessary to the tool plus protection. Cone knife folder on the chip will cause ATC error, or even damage knife folders, and the possibility of spindle. Some processing centre at the transfer, and the tool side. When the ATC command is called, the transfer-cutter knives will be removed, the machine go forward, and positioning with the ATC, in line with the position. 180 o "Rotary ATC devices can be used horizontal machine, can also be used for vertical machining centers.
2. 2 ATC head-turret installed
With rotating CNC machine tool often used such ATC devices, with a few turret head spindle, each with a spindle on both knives, the first tower interim process can be automatic tool change-realization. The advantage is simple structure, tool change time is short, only about 2 s. However, due to spatial constraints, the number of spindle can not be too much, usually only apply to processes less, not to high precision machine tools, such as the NC drill, such as CNC milling machine. In recent years there has been a mechanical hand and the turret head with a knife for the automatic tool change ATC devices, as shown in Figure 2.3. It is in fact a turret head ATC, and the knife-ATC device combination. The principle is as follows:
5 turret on the first two tool spindle 3 and 4, when using the tool spindle 4 processing tool, the manipulator 2 will be the next step to the need for the tool does not work on the tool spindle 3 until after the completion of this process , the first rotary turret 180 o, ATC completed. ATC most of their time and processing time coincidence, the only real tool change time turret transposition of the first time, this approach mainly used for ATC and NC NC drilling file bed. 2. 3.Daidao system for the automatic tool change
Figure 2.4 shows the knife and the whole machine tool CNC machine tools for the appearance of Fig.
Figure 2.5 shows the knife and split-type machine to the appearance of CNC machine tool plans.
At this point, knife storage capacity, a heavier tool can, and often additional transport unit to complete the knife between the spindle and cutting tool transport.
Daidao the knife from the ATC, the election knives, automatic loading and unloading machine tool and tool exchange institutions (manipulator), composed of four parts, used widely.
Tool Automatic Tool Change the manipulator system, the whole process more complicated ATC. We must first used in the processing of all installed in the standard tool on the knife handle in the machine outside the pre-size, according to a certain way Add to the knife. ATC, selected first in the knife knife, and then from ATC, from the knife from the knife or spindle, exchange, the new knife into the spindle, the old knife back into the knife.
ATC, as the former two knives to accommodate a limited number can not be too many, can not
meet the needs of complex parts machining, CNC machine tool Automatic Tool Change Daidao the use of the automatic tool change devices. The knife has more capacity, both installed in the spindle box side or above. As for the automatic tool change Daidao device CNC machine tool spindle box only a spindle, spindle components to high stiffness to meet the machining requirements. The number of establishments in larger knife, which can meet the more complex parts of the machining processes, significantly improving productivity. Daidao system for the automatic tool change applied to drilling centres and CNC machining centers. The comparison drawn Daidao automatic tool change system is the most promising.
3.PLC control of the knife random mode of election
3. 1Common methods of automatic election knife
Automatic control of the knife CNC refers to the system after the implementation of user instructions on the knife library automation process, including the process to find knives and automatic tool change [(63,71]. CNC Machining Center device (CNC) directive issued by the election knife , a knife, the tool required to take the knife position, said the election automatic knife. automatically elected knife There are two ways: random sequence election knives and knife election method.
3.1.1 order election knife
Tool Selection order is the process tool according to the sequence of the insert knife, the use of knives in order to take place, used knives back at the original knife, can also order Add Block, a knife. In this way, no need Tool identification devices, and drive control is a relatively simple, reliable and can be used directly from the points of the knife machinery to achieve. But the knives in each of the tool in different processes can not be reused, if the tool is installed in accordance with the order of the knife, there will be serious consequences. The need to increase the number of knives and knife the capacity of the tool and reduce the utilization of the knife. 3.1.2Random election knife
Random election under the knife is arbitrary instructions to select the required tools, then there must be tool identification devices. Tool knife in the library do not have the processing in accordance with the order of the workpiece can be arbitrary storage. Each of the tool (or knife
blocks) are for a code, automatic tool change, the rotary cutter, every tool have been the "tool identification device" acceptable identification. When CNC tool code and the code in line with directives of the tool selected, the rotary cutter knives will be sent to the ATC position, waiting to grab manipulator. Random knife election is the advantage of the cutter knife in the order has nothing to do with the processing sequence, the same tool can be used repeatedly. Therefore, the relatively small number of knives, knife the corresponding smaller. Random elections knife on the tool must be coded to identify. There are three main coding.
1. Tool coding. Adopt special knife handle structure coding, the drawbars on the knife handle back-end packages such as spacing of the coding part of the lock-nut fixed. Coding diameter ring diameter of a size two, respectively, said that binary "1" and "0" to the two rings are different, can be a series of code. For example, there are six small diameter of the ring can be made to distinguish between 63 (26-1 = 63) of the coding tool. All of 0 normally not allowed to use the code, to avoid the cutter knife Block did not confuse the situation.
2. Knife Block coding. On the knife Block coding, coding tool, and tool into line with the number of knives in the Block. ATC knife when the rotation, so that each knife seats followed through knowledge knife, knife found blocks, knives stopped the rotation. At this time there is no knife handle encoding part of the knife handle simplified.
3. Annex coding methods. This style of coding keys, coded cards, coding and coding-disc, which is the most widely used coding keys.First to knives are attached to a tool of the show wrapped coding keys, and when the cutter knife to the store at knife in, so put the number of keys to remember knife Block Road, will be inserted into key to the coding Block next to the key hole in the seat for the knife to the numbers.
Conclusion
Focused on in today's manufacturing environment tool storage and management of new models and methods, practical application of good results in systems integration and optimization, and other aspects of operations will be further explored, so that it has a higher theoretical and practical level.
译文：
机床刀具设计
课题研究意义
机床原来的刀库控制程序是单独设计的，没有采用刀具管理系统，功能也比较单一，只实现了刀库刀具的找刀、刀库最短路径定位、主轴换刀，而且不支持大型刀具。
在刀库自动选刀方面，在计算机记忆式选刀的基础上采用了西门子840D特色功能，使选刀程序更简洁，并完成空刀套的查找。刀库快速换刀利用STEP-7完成编程，并在实际中得到验证。在刀库定位问题上，PLC程序控制采用模块化设计方法，这对今后生产类似机床将十分有利，很容易将其利用到其他机床上。自动换刀系统将以较快的速度增长，缩短换刀时间，提高刀具的定位精度是重要的手段，有利于数控技术的发展。
刀具及其元件库存是现代生产管理中的重要环节, 特别是大型车间管理。传统的人工记帐管理方式, 效率低下, 错误率高, 且信息数据不能共享, 刀具的使用状态和寿命周期无法跟踪, 不能适应当前信息化管理需要。结合生产实际, 我们在车间刀具准备间建立刀具贮存立体库系统, 以满足车间刀辅具储存与管理的需要。
该系统采用最优化技术, 利用计算机存储的大量库存信息, 能及时、准确、全面地反映刀具库的库存情况。整个系统采用图形界面, 人机对话由中文菜单提示, 可实现各种功能选择和各种信息的输入。管理系统采用在线帮助功能。可通过车间管理层、网络系统实现信息管理和共享。具有自动库存管理、刀具入库管理、刀具出库管理和统计查询功能。
1.系统组成及其控制结构
整个系统包括机械结构及电气控制系统。
1.1.1 机械结构及工作原理
刀具库由支架、驱动机构、传动系统、刀架、护罩、电气控制系统等部分组成。支架由立柱、横梁、上下导向环轨、支撑地轨组成。
1)驱动机构该系统选用了变频调速的方法。采用锥形制动电机, 带变频调速, 经摆线针轮减速器, 通过链轮传动。
2)拖动与传动系统采用变频控制技术。通过变频调速, 可使传动轴转速在正常范围内调节使刀架回转速度控制到5～30mm in, 2 个传动轴各带上、下2 个链轮通过上、下2 条异形滚子链带动货架转动。链条胀紧机构采用螺纹调节胀紧, 为定期胀紧方式。调节时上、下链条松度调节一致, 使链条受力均匀。
3)刀架与防护罩整库共有14 列独立刀架。其中13 列为插座式刀架, 1 列为抽屉式刀架, 每个刀架背部通过销轴与上、下输送链链板联接, 底部安装滚轮, 链条转动带动刀架沿地轨转动。插座式刀架分BT40 刀架和BT50 刀架 2 种形式。为加强管理, 保证安全, 美化造型, 货架外围加防护罩。抽屉式刀架分 6 个抽屉放置其他刀辅具, 可分类装存一些刀辅具, 如钻头、车刀等。
1.1.
2. 电气控制系统
本刀具储存系统的电气控制主要是对其货架进行运行控制和位置控制。运行控制包括运行设备的启动、制动控制。位置控制主要是对货架位置和地址进行检测。控制系统框图如图1 所示。
图1刀具库控制系统图
1)电气传动水平旋转刀具储存系统各机械的动作都属于反复短时工作制。而且系统在运行时需要几种速度, 因此传动系统需要调速, 所以该系统选用了变频调速的方法, 可以采用结构简单、运行可靠的变频器和变频电动机。
2)控制方式该系统分为手动和自动控制2 种控制方式, 手动控制一般作为调试用和备用的工作方式; 自动控制方式为本系统计算机(IPC)和控制单元(变频器、接触器等)组成的一个自动控制系统。
3)位置及定位精度检测本系统中自动认址和位置检测采用了接近开关作为检测元器件, 通过光点隔离继电器板和记数板对接近开关采集的信号进行记数和运算处理, 采用最优路径寻址方式确定货架的当前位置和货架的目的位置。为了使系统定位更准确, 采用了2 只光电开关, 分别检测2 个货架的2 只检测片。
1.2.刀库的功能
刀库的作用是储备一定数量的刀具，机械手实现主轴上刀具的互换}zs}a刀具的类型有盘式刀库、链式刀库等多种形式，刀库的形式和容量要根据机床的工艺范围来确定。
1.3.常见类型
刀库是存储刀具的装置，常见的刀库主要有以下几种形式:
(1)转塔式刀库
包括水平转塔头和垂直转塔头两种，见图2.6a)与b):
(2)盘式刀库
盘式刀库中刀库呈盘状,刀具沿盘面垂直排列(包括径向取刀和轴向取刀),沿盘面径向排列或成锐角排列的形式的刀库。结构简单、紧凑,应用较多,但刀具单环排列,空间利用率低。见图2.7a)~c)。若增加刀库容量必须使刀库的外径增大,那么转动惯量也相应增大,选刀运动时间长。刀具数量一般不多于32把。刀具呈多环排列的刀库的空间利用率高,但必然使得取刀机构复杂,适用于机床空间受限制而刀库容量又较大的场合。双盘式结构是两个较小容量的刀库分置于主轴两侧,布局较紧凑,储刀数量也相应增大,适用于中小型加工中心。
(3)链式刀库
包括单环链和多环链，链环形式可有多种变化，见图2.8a)~c)，基本结构见图2. 8do 特点:适用于刀库容量较大的场合，所占的空间小，一般适用于刀具数在30-120把。仅增加链条长度即可增加刀具数，可以不增加圆周速度其转动惯量不像盘式刀库增加的那样大。
(4)直线式刀库和组合刀库
直线式刀库结构简单如图2. 9，刀具单行排列，刀库容量小，多用于数控车床和钻床
上。由于刀库位置固定，换刀动作由主轴完成，无需机械手。组合刀库一般是转塔式刀库的组合、转塔式与盘式刀库的组合及链式刀库的组合。每单个刀库的储刀量较小，换刀速度快。另外还有一些密集型的鼓轮式、弹匣式和格子式刀库，这些密集型刀库虽.占地面积小，但由于结构限制，基本上不用于单机加工中心，多用于FMS的集中供刀系统。
1.4.刀库的容量
刀库的容量首先要考虑加工工艺的需要，从使用角度出发，一般为10~40把刀，刀库
的利用率会高，而结构比较紧凑。
1.5.刀具的选择方式
(1)顺序选择将刀具按加工工序的顺序，依次放入刀库的每一个刀座内。每次换刀时，
刀库顺序转动一个刀座位置，并取出所需要的刀具，己经使用过的刀具可以放回原来的刀座内，也可以顺序放入下一个刀座内。但由于刀库中刀具在不同的工序中不能重复使用，必须增加刀库的容量，降低了利用率。
(2)任意选择目前大多数的数控系统都采用任意选刀的方式，其分为刀套编码、刀具编码和记忆式等三种。刀具编码或刀套编码需要在刀具或刀套上安装用于识别的编码条，一般都是根据二进制编码的原理进行编码。刀具编码选刀方式采用了一种特殊的刀柄结构，并对每把刀具编码。每把刀具都具有自己的代码，因而刀具可在不同的工序中多次重复使用，换下的刀具不用放回原刀座，刀库的容量也可相应减少。本文采用记忆式选刀，这种方式能将刀具号和刀库中的刀套位置对应地记忆在数控系统的PLC中，无论刀具放在哪个刀套内，刀具信息都始终记存在PLC内。刀库上装有位置检测装置，可获得每个刀套的位置。这样刀具就可以任意取出并送回。刀库上还设有机械原点，使每次选刀时就近选取。
1.6.刀库的控制方式
(1)刀库作为系统的定位轴来控制。在梯形图中根据指令的T码进行运算比较后输出角度和速度指令到刀库伺服驱动刀库伺服电机。刀库的容量、旋转速度、加/减速时间等均可在系统参数中设定，此种方式不受外界因素影响定位准确、可靠但成本较高。
(2)刀库由液压马达驱动，有快/慢速之分，用接近开关计数并定位。在梯形图中比较系统存储的当前刀号(主轴上的刀)和目标刀号(预选刀)并运算，再输出旋转指令，同时判断按最短路径旋转到位。这种方式需要足够的液压动力和电磁阀刀库旋转速度可通过节流阀调整。但使用一段时间后可能会因为油质、油压、油温及环境因素的变化而影响运动速度和准确性。一般用于不需频繁换刀的大中型机床。
(3)刀库由交流异步电动机驱动凸轮机构(马氏机构)，用接近开关计数，这种方式运行稳定，定位准确可靠一般与凸轮机械手配合使用，换刀速度快，定位准。
2.换刀装置的主要类型,特点和适用范围
2.1.自动回转刀架
自动回转刀架是数控机床上使用的一种简单的自动换刀装置，有四方刀架和六角刀架等多种形式，回转刀架上分别安装有四把、六把或更多的刀具，并按数控指令进行换刀。回转刀架又有立式和卧式两种，结构比较简单，适用于经济数控车床。
回转刀架在结构上必须具有良好的强度和刚度，以承受粗加工时切削抗力和减少刀架在切削力作用下的变形，提高加工精度。回转刀架还要选择可靠的定位方案和合理的定位结构，以保证回转刀架在每次转位之后具有较高的重复定位精度(一般为0.001 ~0.005mm )。图2.1所示为螺旋升降式四方刀架。
在自动回转刀架中最简单的换刀装置是180o回转式换刀装置，如图2.2所示。接到换刀指令后，机床控制系统便将主轴控制到指定换刀位置;与此同时，刀具库运动到适当位置，换刀装置回转并同时与主轴、刀具库的刀具相配合;拉杆从主轴刀具上卸掉，换刀装置将刀具从各自的位置上取下;换刀装置回转180o并将主轴刀具与刀具库刀具带走;换刀装置回转的同时，刀具库重新调整其位置，以接受从主轴取下的刀具;接下来，换刀装置将要换上的刀具与卸下的刀具分别装入主轴和刀具库:最后，换刀装置转回原“待命”位置。至此，换刀完成，程序继续运行。这种换刀装置的主要优点是结构简单、涉及的运动少、换刀快。主要缺点是刀具必须存放在与主轴平行的平面内，与侧置后置刀具库相比，切屑及切削液易进入刀夹，因此必须对刀具另加防护。刀夹锥面上有切屑会造成换刀误差，甚至有损坏刀夹与主轴的可能。有些加工中心使用了传递杆，并将刀具库侧置。当换刀指令被调用时，传递杆将刀具库的刀具取下，转到机床前方，并定位于与换刀装置配合的位置。180o“回
转式换刀装置既可用于卧式机床，也可用于立式机床。
2. 2.转塔头式换刀装
带有旋转刀具的数控机床常采用此种换刀装置，转塔头上装有几个主轴，每个主轴上均装一把刀具，加工过程中转塔头可自动转位实现换刀。其优点是结构简单，换刀时间短，仅为2s左右。但由于受空间位置的限制，主轴数目不能太多，通常只适用于工序较少、精度要就不高的机床，如数控钻床、数控铣床等。近年来出现了一种用机械手和转塔头配合刀库进行换刀的自动换刀装置，如图2.3所示。它实际上是转塔头换刀装置和刀库式换刀装置的结合。其原理如下:
转塔头5上有两个刀具主轴3和4，当用刀具主轴4上的刀具进行加工时，可由机械手2将下一步需要的刀具换至不工作的刀具主轴3上，待本工序完成后，转塔头回转180o，完成换刀。因其换刀时间大部分和加工时间重合，真正换刀时间只需转塔头转位的时间，这种换刀方式主要用于数控钻床和数控锉床等。
2. 3.带刀库的自动换刀系统
图2.4所示为刀库与机床为整体式数控机床的外观图。
图2.5所示为刀库与机床为分体式数控机床的外观图。
此时，刀库容量大，刀具可以较重，常常附加运输装置来完成刀库与主轴之间刀具的运输。
带刀库的换刀装置由刀库、选刀机构、刀具自动装卸机械及刀具交换机构(机械手)等四部分组成，应用广泛。
刀库机械手自动换刀系统，整个换刀过程比较复杂。首先要把加工过程中使用的全部刀具安装在标准刀柄上，在机外进行尺寸预调后，按一定的方式放入刀库。换刀时，先在刀库中选刀，再由换刀装置从刀库或主轴上取刀，进行交换，将新刀装入主轴，旧刀放回刀库。
由于前两种换刀装置容纳的刀具数量有限不能太多，不能满足复杂零件的加工需要，所以自动换刀数控机床多采用带刀库的自动换刀装置。刀库具有较大容量，既可安装在主轴箱的侧面或上方。由于带刀库的自动换刀装置的数控机床的主轴箱内只有一根主轴，主轴部件的刚度要高，以满足精密加工要求。刀库内数量较大，因而能满足复杂零件的多工
序加工，大大提高生产率。带刀库的自动换刀系统适用于数控钻削中心和加工中心。进行