數(shù)控銑床畢業(yè)設(shè)計外文翻譯 2

1、<p>　　7.1 INTRODUCTION</p><p>　　After lathes, milling machines are the most widely used for manufacturing applications. In milling, the workpiece is fed into a rotating milling cutter, which is a multi-

2、point tool as shown in Fig. 7.1, unlike a lathe, which uses a single point cutting tool. The tool used in milling is called the milling cutter.</p><p>　　Fig. 7.1 Schematic diagram of a milling operation <

3、;/p><p>　　The milling process is characterised by:</p><p>　　Interrupted cutting Each of the cutting edges removes material for only a part of the rotation of the milling cutter. As a result, the c

4、utting edge has time to cool before it again removes material. Thus the milling operation is much more cooler compared to the turning operation. This allows for a much larger material rates.</p><p>　　Small s

5、ize of chips Though the size of the chips is small, in view of the multiple cutting edges in contact a large amount of material is removed and as a result the component is generally completed in a single pass unlike the

6、 turning process which requires a large number of cuts for finishing.</p><p>　　Variation in chip thickness This contributes to the non-steady state cyclic conditions of varying cutting forces during the con

7、tact of the cutting edge with the chip thickness varying from zero to maximum size or vice versa. This cyclic variation of the force can excite any of the natural frequencies of the machine tool system and is harmful to

8、the tool life and surface finish generated</p><p>　　A milling machine is one of the most versatile machine tools. It is adaptable for quantity production as well as in job shops and tool rooms. The versatili

9、ty of milling is because of the large variety of accessories and tools available with milling machines. The typical tolerance expected from the process is about ± 0.050 mm. </p><p>　　7.2 TYPES OF MILLIN

10、G MACHINES</p><p>　　To satisfy various requirements milling machines come in a number of sizes and varieties. In view of the large material removal rates milling machines come with a very rigid spindle and l

11、arge power. The varieties of milling machines available are:</p><p>　　(i) Knee and Column type</p><p>　　(a) horizontal</p><p>　　(b) vertical</p><p>　　(c) universal</

12、p><p>　　(d) turret type</p><p>　　These are the general purpose milling machines, which have a high degree of flexibility and are employed for all types of works including batch manufacturing. A lar

13、ge variety of attachments to improve the flexibility are available for this class of milling machines.</p><p>　　(ii) Production (Bed) type</p><p>　　(a) simplex</p><p>　　(b) duplex&l

14、t;/p><p>　　(c) triplex</p><p>　　These machines are generally meant for regular production involving large batch sizes. The flexibility is relatively less in these machines which is suitable for pro

15、ductivity enhancement.</p><p>　　(iii) Plano millers</p><p>　　These machines are used only for very large workpieces involving table travels in meters.</p><p>　　(iv) Special type<

16、/p><p>　　(a) Rotary table</p><p>　　(b) Drum type</p><p>　　(c) Copy milling (Die sinking machines)</p><p>　　(d) Key way milling machines </p><p>　　(e) Spline

17、 shaft milling machines</p><p>　　These machines provide special facilities to suit specific applications that are not catered to by the other classes of milling machines.</p><p>　　7.2.1 Knee an

18、d Column Milling Machines</p><p>　　The knee(升降臺) and column type is the most commonly used machine in view of its flexibility and easier setup. A typical machine construction is shown in Fig. 7.2 for the hor

19、izontal axis. The knee houses the feed mechanism and mounts the saddle and table. The table basically has the T-slots running along the X-axis for the purpose of work holding. The table moves along the X-axis on the sadd

20、le while the saddle moves along the Y-axis on the guide ways provided on the knee. </p><p>　　The feed is provided either manually with a hand wheel or connected for automatic by the lead screw, which in turn

21、 is coupled to the main spindle drive. The knee can move up and down (Z-axis) on a dovetail provided on the column.</p><p>　　Fig. 7.2 Horizontal knee and column type milling machine </p><p>　　T

22、he massive column at the back of the machine houses all the power train including the motor and the spindle gearbox. The power for feeding the table lead screw is taken from the main motor through a separate feed gearbox

23、. Sometimes a separate feed motor is provided for the feed gearbox as well.</p><p>　　While the longitudinal and traverse motions are provided with automatic motion, the raising of the knee is generally made

24、manually.</p><p>　　The spindle is located at the top end of the column. The arbour used to mount the milling cutters is mounted in the spindle and is provided with a support on the other end to take care of

25、the heavy cutting forces by means of an overarm with bearing. As shown in Fig. 7.2 the overarm extends from the column with a rigid design. The spindle nose has the standard Morse taper of the suitable size depending upo

26、n the machine size.</p><p>　　The milling cutters are mounted on the arbour at any desired position, the rest of the length being filled by standard hardened collars of varying widths to fix the position of t

27、he cutter. The arbour is clamped in the spindle with the help of a draw bar and then fixed with nuts.</p><p>　　Milling machines are generally specified on the following basis:</p><p>　　(i) Size

28、of the table, which specifies the actual working area on the table and relates to the maximum size of the workpiece that can be accommodated.</p><p>　　(ii) Amount of table travel, which gives the maximum axi

29、s movement that is possible. </p><p>　　(iii) Horse power of the spindle, which actually specifies the power of the spindle motor used. Smaller machines may come with 1 to 3 hp while the production machines m

30、ay go from 10 to 50 hp. </p><p>　　Another type of knee and column milling machine is the vertical axis type. Its construction is very similar to the horizontal axis type, except for the spindle type and loca

31、tion.</p><p>　　The vertical axis milling machine is relatively more flexible (Fig. 7.4) and suitable for machining complex cavities such as die cavities in tool rooms. The vertical head is provided with a sw

32、iveling facility in horizontal direction whereby the cutter axis can be swivelled. This is useful for tool rooms where more complex milling operations are carried out.</p><p>　　The spindle is located in the

33、vertical direction and is suitable for using the shank mounted milling cutters such as end mills, In view of the location of the tool, the setting up of the workpiece and observing the machining operation is more conveni

34、ent.</p><p>　　Fig, 7.3 Vertical knee and column type milling machine</p><p>　　Fig.7.4 Some of the milling operations normally carried out on vertical axis machines</p><p>　　The un

35、iversal machine has the table which can be swivelled in a horizontal plane at about 45o to either the left or right. This makes the universal machine suitable for milling spur and helical gears as well as worm gears and

36、cams.</p><p>　　7.2.2 Bed Type Milling Machine</p><p>　　In production milling machines it is desirable to increase the metal removal rates. If it is done on conventional machines by increasing t

37、he depth of cut, there is possibility of chatter. Hence another variety of milling machines named as bed type machines are used which are made more rugged and are capable of removing more material. The ruggedness is obta

38、ined as a consequence of the reduction in versatility.</p><p>　　The table in the case of bed type machines is directly mounted on the bed and is provided with only longitudinal motion.</p><p>　　

39、The spindle moves along with the column to provide the cutting action. Simplex machines (Fig. 7.5) are the ones with only one spindle head while duplex machines have two spindles (Fig. 7.6). The two spindles are located

40、on either side of a heavy workpiece and remove material from both sides simultaneously.</p><p>　　Fig. 7.5 Simplex bed type milling machine</p><p>　　Fig. 7.6 Duplex bed type milling machine <

41、;/p><p>　　7.3 MILLING CUTTERS</p><p>　　There are a large variety of milling cutters available to suit specific requirements. The versatility of the milling machine is contributed to a great extent

42、by the variety of milling cutters that are available.</p><p>　　7.3.1 Types of Milling Cutters</p><p>　　Milling cutters are classified into various types based on a variety of methods.</p>

43、<p>　　(i) Based on construction:</p><p>　　(a) Solid </p><p>　　(b) Inserted tooth type</p><p>　　Based on mounting:</p><p>　　(a) Arbor mounted</p><

44、;p>　　(b) Shank mounted</p><p>　　(c) Nose mounted</p><p>　　Base on rotation:</p><p>　　(a) Right hand rotation (counter clockwise)</p><p>　　(b) Left hand rotation (clo

45、ckwise) </p><p>　　Based on helix:</p><p>　　(a) Right hand helix</p><p>　　(b) Left hand helix</p><p>　　Milling cutters are generally made of high speed steel or cemente

46、d carbides. The cemented carbide cutters can be of a brazed tip variety or with indexable tips. The indexable variety is more common since it is normally less expensive to replace the worn out cutting edges than to regri

47、nd them.</p><p>　　Plain milling cutters These are also called slab milling cutters and are basically cylindrical with the cutting teeth on the periphery as shown in Fig. 7.7. These are generally used for m

48、achining flat surfaces.</p><p>　　Fig. 7.7 Arbor mounted milling cutters for general purpose</p><p>　　Light duty slab milling cutters generally have a face width, which is small of the order of

49、25 mm. They generally have straight teeth and large number of teeth.</p><p>　　Heavy duty slab milling cutters come with a smaller number of teeth to allow for more chip space. This allows taking deeper cuts

50、and consequently high material removal rates.</p><p>　　Helical milling cutters have a very small number of teeth but a large helix angle. This type of cutter cuts with a shearing action, which can produce a

51、very fine finish. The large helix angle allows the cutter to absorb most of the end load and therefore the cutter enters and leaves the workpiece very smoothly. </p><p>　　Side and face milling cutters Thes

52、e have the cutting edges not only on the face like the slab milling cutters, but also on both the sides. As a result, these cutters become more versatile since they can be used for side milling as well as for slot millin

53、g.</p><p>　　Staggered tooth side milling cutters are a variation where the teeth are arranged in an alternate helix pattern. This type is generally used for milling deep slots, since the staggering of teeth

54、provides for greater chip space.</p><p>　　Another variation of the side and face cutter is the half side milling cutter, which has cutting edges only on one side. This arrangement provides a positive rake an

55、gle and is useful for machining on only one side. These have a much smoother cutting action and a long tool life. The power consumed is also less for these cutters.</p><p>　　Fig. 7.8 Special forms of arbor

56、mounted milling cutters </p><p>　　Slitting saws The other common form of milling cutters in the arbor mounted category is the slitting saw. This is very similar to a saw blade in appearance as well as funct

57、ion. Most of these have teeth around the circumference while some have side teeth as well. The thickness of these cutters is generally very small and is used for cutting off operations or for deep slots.</p><p

58、>　　Special form cutters In addition to the general type of milling cutters described above, there are a large number of special form milling cutters available which are used for machining specific profiles. </p&g

59、t;<p>　　Angular milling cutters are made in single or double angle cutters for milling any angle such as 30, 45 or 60o Form relieved cutters are made of various shapes such as circular, corner rounding, convex or

60、concave shapes.</p><p>　　T-slot milling cutters are used for milling T-slots such as those in the milling machine table. The central slot is to be milled first using an end mill before using the T-slot milli

61、ng cutter. Woodruff key seat milling cutters are used for milling as the name suggests, woodruff key seats</p><p>　　Some other special form cutters are dovetail milling cutters and gear milling cutters.</

62、p><p>　　End mills These are shank mounted as shown in Fig. 7.9 and are generally used in vertical axis milling machines. They are used for milling slots, key ways and pockets where other type of milling cutter

63、s cannot be used. A depth of cut of almost half the diameter can be taken with the end mills.</p><p>　　The end mills have the cutting edge running through the length of the cutting portion as well as on the

64、face radially up to a certain length. The helix angle of the cutting edge promotes smooth and efficient cutting even at high cutting speeds and feed rates. High cutting speeds(轉(zhuǎn)速?) are generally recommended for this type

65、 of milling cutters.</p><p>　　Fig. 7.9 Shank mounted milling cutters and various types of end mills </p><p>　　There are a large variety of end mills. One of the distinctions is based on the met

66、hod of holding, i.e., the end mill shank can be straight or tapered. The straight shank is used on end mills of small size and held in the milling machine spindle with the help of a suitable collet. The tapered shank can

67、 be directly mounted in the spindle with the help of the self holding taper. If the taper is small compared to the spindle taper, then an adopter accommodating both the tapers is used.</p><p>　　The end teeth

68、 of the end mills may be terminated at a distance from the cutter center or may proceed till the center (Fig. 7.9 f). Those with the cutting edge up to the center are called slot drills or end cutting end mills since the

69、y have the ability to cut into the solid material (Fig. 7.9 g). The other type of end mills which have a larger number of teeth cannot cut into solid material and hence require a pilot hole drilled before a pocket is mac

70、hined.</p><p>　　The cutting edge along the side of an end mill is generally straight and sometimes can be tapered by grinding on a tool and cutter grinder such that the draft required for mould and die cavit

71、ies can be automatically generated.</p><p><b>　　第七章 銑削</b></p><p><b>　　7.1介紹</b></p><p>　　除了車床，銑床是制造應(yīng)用中最廣泛使用的。在銑削中，工件向旋轉(zhuǎn)的銑削刀具軸線進(jìn)給，如圖7.1所示，是一個多切削刃刀具，這點和車床不同，車

72、床使用的是單尖切削刀具。在銑削中使用的刀具稱為銑削刀具。</p><p><b>　　圓周銑削</b></p><p><b>　　圖7.1銑削原理圖</b></p><p>　　銑削過程可以作如下分類:</p><p><b>　　斷續(xù)切削 </b></p>&

73、lt;p>　　旋轉(zhuǎn)的銑刀中只有一小部分切削刃用來去除材料，因此，切削刃在再開始投入切削之前有時間來冷卻，此外，削削操作同旋轉(zhuǎn)運動相比溫度更低，這就允許相對較大的材料率。</p><p><b>　　體積小的切屑</b></p><p>　　盡管切屑的體積很小,,考慮到多層切削層與大量材料之間的聯(lián)系已經(jīng)消除,導(dǎo)致一些組件主要是通過單次車削而不像需要通過大量切削來完

74、成的車削過程.</p><p><b>　　(3切削厚度變化</b></p><p>　　這是由于在切削過程中切削力不穩(wěn)定的循環(huán)變化而導(dǎo)致切屑厚度的變化范圍從零到無限大或者反之亦然，這個切削力循環(huán)變化可以引起任何機(jī)床刀具系統(tǒng)的固有頻率同時對刀具壽命和產(chǎn)生的表面光潔度有害。</p><p>　　銑床是大多數(shù)的通用機(jī)床之一。它適用于批量生產(chǎn)的同時也

75、適用于加工車間和刀具車間。銑床的通用性在于銑床上有大量的附件和可用刀具。在加工過程中，產(chǎn)品產(chǎn)生的預(yù)期公差大約為±0.05mm。</p><p><b>　　7.2銑床的種類</b></p><p>　　為了滿足不同的需求，銑床出現(xiàn)了許多型號和種類。考慮到高材料去除率的銑床，出現(xiàn)了剛性主軸和大功率。常用的幾種銑床種類如下：</p><p&g

76、t;<b>　?。╥)升降臺種類</b></p><p><b>　　（a）水平的</b></p><p><b>　?。╞）豎直的</b></p><p><b>　?。╟）通用的</b></p><p><b>　　（d）轉(zhuǎn)塔類型的</

77、b></p><p>　　這些都是通用銑床，它們有高度靈活性而且應(yīng)用于所有類型的工件同時包括批量生產(chǎn)。</p><p><b>　　（ii）生產(chǎn)類型</b></p><p><b>　?。╝）單一的</b></p><p><b>　　（b）復(fù)式的</b></p&g

78、t;<p><b>　?。╟）三重的</b></p><p>　　這些機(jī)器大多是為了正常生產(chǎn)，包括大批量生產(chǎn)。它們的靈活性比那些用于提高生產(chǎn)率的機(jī)器會相對來說小一點。</p><p>　?。╥ii)l龍門銑床</p><p>　　這個機(jī)器只能用于大量工件包括工作臺行程，單位為米。</p><p><b

79、>　　（iv）專用種類</b></p><p><b>　?。╝）回轉(zhuǎn)臺</b></p><p><b>　?。╞）鼓形</b></p><p>　?。╟）仿型銑床（開模機(jī)）</p><p><b>　　(d))鍵槽銑床</b></p><

80、p><b>　　(e)花鍵軸銑床</b></p><p>　　這類機(jī)床提供特別的設(shè)備以滿足特定的別的種類銑床不能滿足的應(yīng)用。</p><p>　　7.2.1升降臺銑床</p><p>　　升降臺類機(jī)床鑒于它的靈活性和易安裝性使得它是最被廣泛的應(yīng)用的機(jī)床。典型的臥式水平軸的機(jī)床結(jié)構(gòu)如圖7.2 所示。升降臺支撐著進(jìn)給機(jī)構(gòu)同時安裝著床鞍和工作臺

81、。工作臺主要地有沿著X軸的T型槽，這個槽主要是用來工件的夾緊。工作臺沿著X軸在床鞍上移動，床鞍沿著Y軸在導(dǎo)軌上移動。進(jìn)給由手輪手動地提供，或是由導(dǎo)螺桿相連的自動進(jìn)給，導(dǎo)螺桿轉(zhuǎn)而由主軸驅(qū)動。升降臺能夠在床身提供的銜接上沿Z軸上下移動。</p><p>　　圖7.2 臥式升降臺銑床</p><p>　　在機(jī)床背后巨大的床身內(nèi)裝有所有動力傳動機(jī)構(gòu)，包括電動機(jī)和主軸變速箱。供給工作臺的導(dǎo)螺桿的功率

82、主要通過一個分進(jìn)給變速箱向主要的電動機(jī)獲取。有時也有一個單獨的進(jìn)給電動機(jī)為進(jìn)給變速箱提供動力。盡管縱向和橫向的運動都由自動運動控制，但升降臺的上升一般由手動完成。</p><p>　　主軸位于床身的頂部。常用來安裝刀具的心軸安裝在主軸上，同時在另一端用帶軸承的懸臂提供一種支撐以滿足強(qiáng)大的切削力矩。如圖7.2所示懸臂用一種剛性設(shè)計從床身向外伸出。主軸頭端帶有根據(jù)機(jī)床大小選擇的合適尺寸的標(biāo)準(zhǔn)莫氏錐度。</p&g

83、t;<p>　　銑刀可以再任何需要的位置上安裝在心軸上，長度的其余部分用不同寬度的標(biāo)準(zhǔn)緊固軸環(huán)填充以固定刀的位置。心軸通過牽引桿在主軸中夾緊，然后用螺母固定。</p><p>　　銑床一般按以下分類：</p><p>　?。╥)工作臺的大小，它指定了在工作臺上的實際工作面積和相關(guān)的能夠適應(yīng)的工件的最大尺寸。</p><p>　?。╥i）工作臺行程，它指

84、出了允許的最大軸向運動。</p><p>　　（iii）主軸的馬力，這實際上指定了使用的主軸電動機(jī)的功率。小型機(jī)床可以使1~3馬力，而專用機(jī)床可以是10~50馬力。</p><p>　　另一類升降臺銑床是豎直軸類的。它的結(jié)構(gòu)除了主軸位置和類型外和臥式的基本相同，它的主軸位于垂直位置，適用于適用于適用柄部安裝的銑刀例如平銑刀。鑒于刀具的位置，工件的安裝和切削過程更加方便。</p>

85、<p>　　圖7.3立式升降臺銑床</p><p>　　垂直軸銑床相對更加靈活（圖7.4），同時適合加工復(fù)雜腔如在工具室的模腔。垂直床頭在水平方向上有一個旋轉(zhuǎn)的設(shè)備，靠這個刀具才能夠旋轉(zhuǎn)。這對刀具室非常有用，刀具室就是更多銑削操作實現(xiàn)的地方。</p><p>　　通用銑床的工作臺能夠在水平方向±45°范圍內(nèi)旋轉(zhuǎn)，這使得通用銑床適用于加工尖腳和斜齒圓柱齒輪以

86、及渦輪和凸輪。</p><p>　　7.2.2床身式銑床</p><p>　　在生產(chǎn)的銑床，提高材料的去除率是可取的。如果傳統(tǒng)機(jī)械通過提高切削深度得以實現(xiàn)，那么將會產(chǎn)生顫動。因此另一類制造的更加堅固，有能力去除更多材料名叫床身式銑床投入使用。強(qiáng)度的獲得是減少它的通用性的結(jié)果。</p><p>　　圖7.4一般在垂直軸機(jī)床上實現(xiàn)的一些銑削操作</p>&

87、lt;p>　　圖7.5單向的床身式銑床</p><p>　　床身式銑床的工作臺直接安裝在床身上，并且只提供縱向運動。</p><p>　　主軸沿著床身運動來提供切削運動。單向的機(jī)床（圖7.5）是只有一個主軸頭的機(jī)床，而雙向的機(jī)床是有兩個主軸頭(圖7.6)。這兩個主軸頭位于工件的兩側(cè)，同時從兩側(cè)去除材料。</p><p>　　圖7.6雙向的床身式銑床</p

88、><p><b>　　7.3銑刀</b></p><p>　　為了適應(yīng)特定的加工需求有很多種類的銑削刀具。銑床的萬能性在很大程度上歸功于一系列可選銑刀的多樣性。</p><p><b>　　7.3.1銑刀類型</b></p><p>　　銑刀通過加工方式可被分為不同的種類</p><

89、p>　　(ⅰ)根據(jù)結(jié)構(gòu)不同：</p><p><b>　　整體的</b></p><p><b>　　鑲齒類</b></p><p><b>　　根據(jù)底座不同：</b></p><p><b>　　心軸安裝的</b></p><p

90、><b>　　柄部安裝的</b></p><p><b>　　機(jī)頭安裝的</b></p><p><b>　　根據(jù)旋轉(zhuǎn)不同：</b></p><p><b>　　右旋（逆時針）</b></p><p><b>　　左旋（順時針）</b

91、></p><p><b>　　根據(jù)螺旋不同:</b></p><p><b>　　(a)右手螺旋</b></p><p><b>　　(b)左手螺旋</b></p><p>　　銑刀大多數(shù)由高速鋼或者硬質(zhì)合金制造。硬質(zhì)合金的銑刀可以用黃銅焊接系列或者用可轉(zhuǎn)位的刀尖?？赊D(zhuǎn)

92、為類銑刀更加普遍因為替換切削刃磨壞的刀具比重新再磨更便宜。</p><p><b>　　面銑刀</b></p><p>　　也被稱為板銑刀，通常是邊緣帶有切齒的圓柱體，如圖7.7所示。它們大多數(shù)用來加工平坦的表面。</p><p>　　輕負(fù)荷平板銑刀大多是有一個小的大約25mm尺寸的齒面槽。它們大多有直齒，并且數(shù)量較大。</p>

93、<p>　　重型平板銑床大多齒數(shù)較少以滿足更多的排屑空間。這個允許深入切削以及較高的材料去除速率。</p><p>　　螺旋銑刀，有非常小的齒數(shù)但是有很大的螺旋角。這個種類的銑刀有能產(chǎn)生很好切削面的剪切作用。同時，較大的螺旋角允許銑刀允許銑刀吸收大量的端點載荷，因此刀具進(jìn)入和離開工作表面都能很平滑。</p><p>　　三面刃銑刀 該類銑刀的切削刃不只是類似平板銑刀的一面，而是

94、在兩面都有。因此，這類銑刀變得更加萬能因為它們能用于邊緣切削的同時也可以用于槽銑削。</p><p>　　交錯齒側(cè)銑刀是被安排成交替螺旋形齒的一系列刀具。該類刀具大多用與銑削深槽，因為齒面的交錯提供了更大的排屑空間。</p><p>　　另一系列的側(cè)平面銑刀是只有一面有銑削刃的半面銑刀。這樣的安排提供了一個確定的傾角并且對于只加工一面的加工過程有利。該銑刀具有更平滑的銑削過程以及更長的刀具

95、壽命。能量的消耗也小于其他種類刀具。 </p><p>　　圖7.7一般用途的用心軸安裝的銑刀</p><p>　　切割鋸 在常用的用心軸安裝的范疇內(nèi)，其他的常用的刀具種類是切割鋸。它在功能和表面上都類似于鋸片，大多數(shù)的圓鋸有在周圍是有鋸齒的，一些也有邊齒。這些圓鋸的切削厚度通常很薄，而且通常被用作深槽的切割 特殊形式的刀具 除了以上描述的普通類型的銑刀，還有很多用來加工特殊

96、剖面的可選擇的特殊形式的銑刀。角銑刀是由單角度和多角度構(gòu)成的，用來加工任何角度的角，如30°、45°、60°。 鏟齒銑刀由不同的形狀組成，如圓形的，圓角的，凸的或者是凹的。</p><p>　　圖7.8特殊形式的心軸安裝的銑刀</p><p>　　T 型槽銑刀用來銑在銑床工作臺上的T型槽。這樣的中央槽首先用平銑刀銑，然后再用T型槽銑刀銑削。半圓鍵座銑

97、刀正如它的名字一樣用來加工半圓鍵座。</p><p>　　其他特殊形式的銑刀是燕尾槽銑刀和齒輪銑刀。</p><p>　　平銑刀 如圖7.9所示，這類銑刀都是柄部安裝銑刀，一般用垂直軸銑床。它們用來銑槽、鍵槽、凹槽，這些加工位置其他類銑刀不能用。大學(xué)刀具半徑大小的切削深度時選用平銑刀。</p><p>　　圖7.9柄部安裝銑刀和不同類型的端銑刀</p>

98、<p>　　平銑刀的刀刃在貫穿部分切削長度的同時在表面上也達(dá)到了一定的長度。切削刃的螺旋角保證了即使在很高的切削速度和進(jìn)給速度的同時也有較好的平滑性。這類銑刀適用于高速切削。</p><p>　　平銑刀有很多種類。區(qū)分之一的方式就是根據(jù)夾緊方式，平銑刀的刀柄可以是直的也可以是錐形的，小型銑刀一般用直柄的并且在合適的夾頭的幫助下固定在銑床主軸上。錐柄的可以直接借助它自身的錐度安裝在主軸上，如果錐度比主軸

99、錐度小，那么就會采用一個適合的錐度來適應(yīng)這兩個方面。</p><p>　　平銑刀的刀齒到距離刀具中心一段距離后結(jié)束或者直到刀具中心（如圖7.9.f）。那些切削刃到刀具中心的刀具叫槽鉆或者端面銑刀，因為他們有能力切入固體材料（圖7.9.g）。另一類有很多齒的平銑刀不能直接切入固體材料，因此在加工一個孔前需要一個鉆過的導(dǎo)孔。</p><p>　　平銑刀側(cè)面的切削刃一般是直的，有時也在刀具上磨成