機(jī)床刀具設(shè)計(jì)外文翻譯 (2)

1、<p><b>　　武漢工業(yè)學(xué)院</b></p><p>　　畢業(yè)設(shè)計(jì)（論文）外文參考文獻(xiàn)譯文本</p><p><b>　　2013屆</b></p><p>　　譯文出處M.B.Ko.Design of automatic tool changer for CNC machines.M.Scthesis,Me

2、chanical EngineeringDepartmet, METU, Ankara, Turkey 1995 </p><p>　　畢業(yè)設(shè)計(jì)(論文)題目 BT40×24型斗豎式刀庫研究與設(shè) 計(jì) </p><p>　　院（系） 機(jī)械工程學(xué)院 </p><p>　　專業(yè)名稱 機(jī)械設(shè)計(jì)制造及其自動(dòng)化

3、</p><p>　　學(xué)生姓名 xxxxxxxxx </p><p>　　學(xué)生學(xué)號 090309815 </p><p>　　指導(dǎo)教師 劉 海 岷 </p><p><b>　　譯文出處： </b></p>&l

4、t;p>　　M.B.Ko.Design of automatic tool changer for CNC machines.M.Scthesis,Mechanical EngineeringDepartmet, METU, Ankara, Turkey 1995</p><p>　　翻譯文獻(xiàn)：Time between failures model and failure analysis of CNC s

5、ystem [J]．.Joumal 2007，14(2)：197-201L </p><p>　　文獻(xiàn)作者：ZHANG H　B，JIA Y Z，ZHOU G W．</p><p><b>　　英語原文：</b></p><p>　　The original knife machine control procedures are designe

6、d individually, not used tool management system, features a single comparison, the knife only has to fin the tool knife, knife positioning the shortest path, axis tool change, but does not support large-scale tool.

7、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 t

8、he </p><p>　　1.System components and control structure</p><p>　　The entire system, including the structure and electrical machinery control systems.</p><p>　　1.1.1Mechanical structu

9、re and working principle</p><p>　　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 trac

10、k, 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.

11、 VVVF adopted, will speed drive shaft in the normal range adjustment to control the speed rotary turret to </p><p>　　1.1.2.Electrical Control System</p><p>　　This tool storage systems is the mai

12、n 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 th

13、e shelves for testing. </p><p>　　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, sp

14、eed 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 auto

15、matic control, manual control as a general reserve and debugging methods of work; ways to the system contr</p><p>　　1.2.The functions of the knife</p><p>　　knife The is the role of reserves a ce

16、rtain number of tools, machine tool spindle in hand to achieve the fungibility a disc sc knife in the library with discoid knife, cutting tool along See how vertical arrangement (including radial and axial from knife fro

17、m 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. D features, and the election procedures knife mor

18、e concise, and complet</p><p>　　1.3.Common types</p><p>　　The knife is a tool storage devices, the common knife mainly in the following forms: (1) the turret knife Including the first level tu

19、rret vertical turret and the first two, see Figure 2.6 a) and b):</p><p>　　(2) the disc cutter </p><p>　　Disc knife in the library with discoid knife, cutting tool along See how vertical arrange

20、ment (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. D

21、 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 t</p><p>　　the ch

22、ain knife   Including single-and multi-ring chain ring chain, chain link can take many forms change, see the basic structure shown Features: knife apply to the larger capacity of the occasion, the space of the s

23、mall 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

24、not increase the disc as large.</p><p>　　(4) linear combination knife and the knife library The linear knife simple structur single order, the capacity of small knife, used for CNC lathe and drill press on.

25、 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 combina

26、tion. Every single knife the knife certificates of smaller, faster tool change. There are also some intensive drum</p><p>　　1.4 Tool storage capacity</p><p>　　Tool storage capacity of the first

27、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.</p><p>　　1.5 Tool options</p>&l

28、t;p>　　(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, h

29、as 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 c

30、apacity and lower utilization rate. (2) most of the arbitrary cho</p><p>　　2. ATC, the main types, characteristics, and the scope of application</p><p>　　2.1 Auto Rotary Tool</p><

31、p>　　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 mor

32、e 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,

33、resistance to bear rough Cutting Tool in the cutting force and redu</p><p>　　Auto Rotary Tool in the simplest of ATC, is 180 º rotary ATC devices, as shown in Figure 2.2 ATC instructions received, the m

34、achine 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 sa. When the ATC command is called, the trans

35、fer-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 h</p><p>　　2. 2 ATC head-turret installed&l

36、t;/p><p>　　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-realizatio

37、n. 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

38、 machine tools, such as the NC drill, such as CNC milling machine. In recent year</p><p>　　when using the tool spindle 4 processing tool, the manipulator 2 will be the next step to the need for the tool does

39、 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 turre

40、t transposition of the first time, this approach mainly used for ATC and NC NC drilling file bed.</p><p>　　2. 3.Daidao system for the automatic tool change</p><p>　　Figure 2.4 shows the knife an

41、d 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 he

42、avier 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

43、and tool exchange institutions (mani</p><p>　　Conclusion Focused on in today's manufacturing environment tool storage and management of new models and methods, practical application of good results in

44、 systems integration and optimization.</p><p>　　譯文 </p><p><b>　　機(jī)床刀具設(shè)計(jì)</b></p><p><b>　　課題研究意義</b></p><p>　　機(jī)床原來的刀庫控制程序是單獨(dú)設(shè)計(jì)的，沒有采

45、用刀具管理系統(tǒng)，功能也比較單一，只實(shí)現(xiàn)了刀庫刀具的找刀、刀庫最短路徑定位、主軸換刀，而且不支持大型刀具。</p><p>　　在刀庫自動(dòng)選刀方面，在計(jì)算機(jī)記憶式選刀的基礎(chǔ)上采用了西門子840D特色功能，使選刀程序更簡潔，并完成空刀套的查找。刀庫快速換刀利用STEP-7完成編程，并在實(shí)際中得到驗(yàn)證。在刀庫定位問題上，PLC程序控制采用模塊化設(shè)計(jì)方法，這對今后生產(chǎn)類似機(jī)床將十分有利，很容易將其利用到其他機(jī)床上。自動(dòng)換

46、刀系統(tǒng)將以較快的速度增長，縮短換刀時(shí)間，提高刀具的定位精度是重要的手段，有利于數(shù)控技術(shù)的發(fā)展。</p><p>　　刀具及其元件庫存是現(xiàn)代生產(chǎn)管理中的重要環(huán)節(jié), 特別是大型車間管理。傳統(tǒng)的人工記帳管理方式, 效率低下, 錯(cuò)誤率高, 且信息數(shù)據(jù)不能共享, 刀具的使用狀態(tài)和壽命周期無法跟蹤, 不能適應(yīng)當(dāng)前信息化管理需要。結(jié)合生產(chǎn)實(shí)際, 我們在車間刀具準(zhǔn)備間建立刀具貯存立體庫系統(tǒng), 以滿足車間刀輔具儲(chǔ)存與管理的需要。&

47、lt;/p><p>　　該系統(tǒng)采用最優(yōu)化技術(shù), 利用計(jì)算機(jī)存儲(chǔ)的大量庫存信息, 能及時(shí)、準(zhǔn)確、全面地反映刀具庫的庫存情況。整個(gè)系統(tǒng)采用圖形界面, 人機(jī)對話由中文菜單提示, 可實(shí)現(xiàn)各種功能選擇和各種信息的輸入。管理系統(tǒng)采用在線幫助功能。可通過車間管理層、網(wǎng)絡(luò)系統(tǒng)實(shí)現(xiàn)信息管理和共享。具有自動(dòng)庫存管理、刀具入庫管理、刀具出庫管理和統(tǒng)計(jì)查詢功能。</p><p>　　1.系統(tǒng)組成及其控制結(jié)構(gòu)</

48、p><p>　　1.1.1 機(jī)械結(jié)構(gòu)及工作原理</p><p>　　刀具庫由支架、驅(qū)動(dòng)機(jī)構(gòu)、傳動(dòng)系統(tǒng)、刀架、護(hù)罩、電氣控制系統(tǒng)等部分組成。支架由立柱、橫梁、上下導(dǎo)向環(huán)軌、支撐地軌組成。</p><p>　　1)驅(qū)動(dòng)機(jī)構(gòu)　該系統(tǒng)選用了變頻調(diào)速的方法。采用錐形制動(dòng)電機(jī), 帶變頻調(diào)速, 經(jīng)擺線針輪減速器, 通過鏈輪傳動(dòng)。</p><p>　　2)拖動(dòng)與

49、傳動(dòng)系統(tǒng)　采用變頻控制技術(shù)。通過變頻調(diào)速, 可使傳動(dòng)軸轉(zhuǎn)速在正常范圍內(nèi)調(diào)節(jié)使刀架回轉(zhuǎn)速度控制到 5～ 30mm in, 2 個(gè)傳動(dòng)軸各帶上、下2 個(gè)鏈輪通過上、下2 條異形滾子鏈帶動(dòng)貨架轉(zhuǎn)動(dòng)。鏈條脹緊機(jī)構(gòu)采用螺紋調(diào)節(jié)脹緊, 為定期脹緊方式。調(diào)節(jié)時(shí)上、下鏈條松度調(diào)節(jié)一致, 使鏈條受力均勻。</p><p>　　3)刀架與防護(hù)罩　整庫共有14 列獨(dú)立刀架。其中 13 列為插座式刀架, 1 列為抽屜式刀架, 每個(gè)刀架背

50、部通過銷軸與上、下輸送鏈鏈板聯(lián)接, 底部安裝滾輪, 鏈條轉(zhuǎn)動(dòng)帶動(dòng)刀架沿地軌轉(zhuǎn)動(dòng)。插座式刀架分BT40 刀架和BT50 刀架 2 種形式。為加強(qiáng)管理, 保證安全, 美化造型, 貨架外圍加防護(hù)罩。抽屜式刀架分 6 個(gè)抽屜放置其他刀輔具, 可分類裝存一些刀輔具, 如鉆頭、車刀等。</p><p>　　1.1.2. 電氣控制系統(tǒng)</p><p>　　本刀具儲(chǔ)存系統(tǒng)的電氣控制主要是對其貨架進(jìn)行運(yùn)行控

51、制和位置控制。運(yùn)行控制包括運(yùn)行設(shè)備的啟動(dòng)、制動(dòng)控制。位置控制主要是對貨架位置和地址進(jìn)行檢測?？刂葡到y(tǒng)框圖如圖 1 所示。</p><p>　　1)電氣傳動(dòng)　水平旋轉(zhuǎn)刀具儲(chǔ)存系統(tǒng)各機(jī)械的動(dòng)作都屬于反復(fù)短時(shí)工作制。而且系統(tǒng)在運(yùn)行時(shí)需要幾種速度, 因此傳動(dòng)系統(tǒng)需要調(diào)速, 所以該系統(tǒng)選用了變頻調(diào)速的方法, 可以采用結(jié)構(gòu)簡單、運(yùn)行可靠的變頻器和變頻電動(dòng)機(jī)。</p><p>　　2)控制方式　該系統(tǒng)分

52、為手動(dòng)和自動(dòng)控制2 種控制方式, 手動(dòng)控制一般作為調(diào)試用和備用的工作方式; 自動(dòng)控制方式為本系統(tǒng)計(jì)算機(jī)(IPC)和控制單元(變頻器、接觸器等)組成的一個(gè)自動(dòng)控制系統(tǒng)。</p><p>　　3)位置及定位精度檢測　本系統(tǒng)中自動(dòng)認(rèn)址和位置檢測采用了接近開關(guān)作為檢測元器件, 通過光點(diǎn)隔離繼電器板和記數(shù)板對接近開關(guān)采集的信號進(jìn)行記數(shù)和運(yùn)算處理, 采用最優(yōu)路徑尋址方式確定貨架的當(dāng)前位置和貨架的目的位置。為了使系統(tǒng)定位更準(zhǔn)確

53、, 采用了 2 只光電開關(guān), 分別檢測2 個(gè)貨架的2 只檢測片。</p><p><b>　　1.2.刀庫的功能</b></p><p>　　刀庫的作用是儲(chǔ)備一定數(shù)量的刀具，機(jī)械手實(shí)現(xiàn)主軸上刀具的互換}zs}a刀具的類型有盤式刀庫、鏈?zhǔn)降稁斓榷喾N形式，刀庫的形式和容量要根據(jù)機(jī)床的工藝范圍來確定。</p><p>　　1.3.常見類型 &l

54、t;/p><p>　　刀庫是存儲(chǔ)刀具的裝置，常見的刀庫主要有以下幾種形式:</p><p><b>　　(1)轉(zhuǎn)塔式刀庫</b></p><p>　　包括水平轉(zhuǎn)塔頭和垂直轉(zhuǎn)塔頭兩種，見圖2.6a)與b): </p><p><b>　　(2)盤式刀庫</b></p><p>

55、　　盤式刀庫中刀庫呈盤狀,刀具沿盤面垂直排列(包括徑向取刀和軸向取刀),沿盤面徑向排列或成銳角排列的形式的刀庫。結(jié)構(gòu)簡單、緊湊,應(yīng)用較多,但刀具單環(huán)排列,空間利用率低。見圖2.7a)~c)。若增加刀庫容量必須使刀庫的外徑增大,那么轉(zhuǎn)動(dòng)慣量也相應(yīng)增大,選刀運(yùn)動(dòng)時(shí)間長。刀具數(shù)量一般不多于32把。刀具呈多環(huán)排列的刀庫的空間利用率高,但必然使得取刀機(jī)構(gòu)復(fù)雜,適用于機(jī)床空間受限制而刀庫容量又較大的場合。雙盤式結(jié)構(gòu)是兩個(gè)較小容量的刀庫分置于主軸兩側(cè)

56、,布局較緊湊,儲(chǔ)刀數(shù)量也相應(yīng)增大,適用于中小型加工中心。</p><p>　　(3)鏈?zhǔn)降稁?</p><p>　　包括單環(huán)鏈和多環(huán)鏈，鏈環(huán)形式可有多種變化，見圖2.8a)~c)，基本結(jié)構(gòu)見圖2. 8do</p><p>　　特點(diǎn):適用于刀庫容量較大的場合，所占的空間小，一般適用于刀具數(shù)在30-120把。僅增加鏈條長度即可增加刀具數(shù)，可以不增加圓周速度其轉(zhuǎn)動(dòng)慣量

57、不像盤式刀庫增加的那樣大</p><p>　　(4)直線式刀庫和組合刀庫</p><p>　　直線式刀庫結(jié)構(gòu)簡單如圖2. 9，刀具單行排列，刀庫容量小，多用于數(shù)控車床和鉆床上。由于刀庫位置固定，換刀動(dòng)作由主軸完成，無需機(jī)械手。組合刀庫一般是轉(zhuǎn)塔式刀庫的組合、轉(zhuǎn)塔式與盤式刀庫的組合及鏈?zhǔn)降稁斓慕M合。每單個(gè)刀庫的儲(chǔ)刀量較小，換刀速度快。另外還有一些密集型的鼓輪式、彈匣式和格子式刀庫，這些密集型

58、刀庫雖.占地面積小，但由于結(jié)構(gòu)限制，基本上不用于單機(jī)加工中心，多用于FMS的集中供刀系統(tǒng)。</p><p><b>　　1.4.刀庫的容量</b></p><p>　　刀庫的容量首先要考慮加工工藝的需要，從使用角度出發(fā)，一般為10~40把刀，刀庫的利用率會(huì)高，而結(jié)構(gòu)比較緊湊。</p><p>　　1.5.刀具的選擇方式</p>&

59、lt;p>　　(1)順序選擇將刀具按加工工序的順序，依次放入刀庫的每一個(gè)刀座內(nèi)。每次換刀時(shí)，刀庫順序轉(zhuǎn)動(dòng)一個(gè)刀座位置，并取出所需要的刀具，己經(jīng)使用過的刀具可以放回原來的刀座內(nèi)，也可以順序放入下一個(gè)刀座內(nèi)。但由于刀庫中刀具在不同的工序中不能重復(fù)使用，必須增加刀庫的容量，降低了利用率。</p><p>　　(2)任意選擇目前大多數(shù)的數(shù)控系統(tǒng)都采用任意選刀的方式，其分為刀套編碼、刀具編碼和記憶式等三種。刀具編碼或

60、刀套編碼需要在刀具或刀套上安裝用于識別的編碼條，一般都是根據(jù)二進(jìn)制編碼的原理進(jìn)行編碼。刀具編碼選刀方式采用了一種特殊的刀柄結(jié)構(gòu)，并對每把刀具編碼。每把刀具都具有自己的代碼，因而刀具可在不同的工序中多次重復(fù)使用，換下的刀具不用放回原刀座，刀庫的容量也可相應(yīng)減少。本文采用記憶式選刀，這種方式能將刀具號和刀庫中的刀套位置對應(yīng)地記憶在數(shù)控系統(tǒng)的PLC中，無論刀具放在哪個(gè)刀套內(nèi)，刀具信息都始終記存在PLC內(nèi)。刀庫上裝有位置檢測裝置，可獲得每個(gè)刀套

61、的位置。這樣刀具就可以任意取出并送回。刀庫上還設(shè)有機(jī)械原點(diǎn)，使每次選刀時(shí)就近選取。</p><p>　　2.換刀裝置的主要類型,特點(diǎn)和適用范圍</p><p>　　2.1.自動(dòng)回轉(zhuǎn)刀架</p><p>　　自動(dòng)回轉(zhuǎn)刀架是數(shù)控機(jī)床上使用的一種簡單的自動(dòng)換刀裝置，有四方刀架和六角刀架等多種形式，回轉(zhuǎn)刀架上分別安裝有四把、六把或更多的刀具，并按數(shù)控指令進(jìn)行換刀?；剞D(zhuǎn)刀架又

62、有立式和臥式兩種，結(jié)構(gòu)比較簡單，適用于經(jīng)濟(jì)數(shù)控車床。</p><p>　　回轉(zhuǎn)刀架在結(jié)構(gòu)上必須具有良好的強(qiáng)度和剛度，以承受粗加工時(shí)切削抗力和減少刀架在切削力作用下的變形，提高加工精度?；剞D(zhuǎn)刀架還要選擇可靠的定位方案和合理的定位結(jié)構(gòu)，以保證回轉(zhuǎn)刀架在每次轉(zhuǎn)位之后具有較高的重復(fù)定位精度(一般為0.001 ~0.005mm )。圖2.1所示為螺旋升降式四方刀架。</p><p>　　在自動(dòng)回轉(zhuǎn)刀

63、架中最簡單的換刀裝置是180º回轉(zhuǎn)式換刀裝置，如圖2.2所示。接到換刀指令后，機(jī)床控制系統(tǒng)便將主軸控制到指定換刀位置;與此同時(shí)，刀具庫運(yùn)動(dòng)到適當(dāng)位置，換刀裝置回轉(zhuǎn)并同時(shí)與主軸、刀具庫的刀具相配合;拉桿從主軸刀具上卸掉，換刀裝置將刀具從各自的位置上取下;換刀裝置回轉(zhuǎn)180º并將主軸刀具與刀具庫刀具帶走;換刀裝置回轉(zhuǎn)的同時(shí)，刀具庫重新調(diào)整其位置，以接受從主軸取下的刀具;接下來，換刀裝置將要換上的刀具與卸下的刀具分別裝入主

64、軸和刀具庫:最后，換刀裝置轉(zhuǎn)回原“待命”位置。至此，換刀完成，程序繼續(xù)運(yùn)行。這種換刀裝置的主要優(yōu)點(diǎn)是結(jié)構(gòu)簡單、涉及的運(yùn)動(dòng)少、換刀快。主要缺點(diǎn)是刀具必須存放在與主軸平行的平面內(nèi)，與側(cè)置后置刀具庫相比，切屑及切削液易進(jìn)入刀夾，因此必須對刀具另加防護(hù)。刀夾錐面上有切屑會(huì)造成換刀誤差，甚至有損壞刀夾與主軸的可能。有些加工中心使用了傳遞桿，并將刀具庫側(cè)置。當(dāng)換刀指令被調(diào)用時(shí)，傳遞桿將刀具庫的刀具取下，轉(zhuǎn)到機(jī)床前方，并定位于與換刀裝置配合的位置。1

65、80º“回轉(zhuǎn)式換刀裝置既可用于臥式機(jī)床，也可用于立式機(jī)床。</p><p>　　2. 2.轉(zhuǎn)塔頭式換刀裝</p><p>　　帶有旋轉(zhuǎn)刀具的數(shù)控機(jī)床常采用此種換刀裝置，轉(zhuǎn)塔頭上裝有幾個(gè)主軸，每個(gè)主軸上均裝一把刀具，加工過程中轉(zhuǎn)塔頭可自動(dòng)轉(zhuǎn)位實(shí)現(xiàn)換刀。其優(yōu)點(diǎn)是結(jié)構(gòu)簡單，換刀時(shí)間短，僅為2s左右。但由于受空間位置的限制，主軸數(shù)目不能太多，通常只適用于工序較少、精度要就不高的機(jī)床，如數(shù)

66、控鉆床、數(shù)控銑床等。近年來出現(xiàn)了一種用機(jī)械手和轉(zhuǎn)塔頭配合刀庫進(jìn)行換刀的自動(dòng)換刀裝置，如圖2.3所示。它實(shí)際上是轉(zhuǎn)塔頭換刀裝置和刀庫式換刀裝置的結(jié)合。其原理如下:</p><p>　　轉(zhuǎn)塔頭5上有兩個(gè)刀具主軸3和4，當(dāng)用刀具主軸4上的刀具進(jìn)行加工時(shí)，可由機(jī)械手2將下一步需要的刀具換至不工作的刀具主軸3上，待本工序完成后，轉(zhuǎn)塔頭回轉(zhuǎn)180º，完成換刀。因其換刀時(shí)間大部分和加工時(shí)間重合，真正換刀時(shí)間只需轉(zhuǎn)塔頭