機(jī)械工程英 語(yǔ)

1、1TheLatheItsConstruction車(chē)床及其結(jié)構(gòu)Alatheisamachinetoolusedprimarilyfproducingsurfacesofrevolutionflatedges.車(chē)床是主要用于生成旋轉(zhuǎn)表面和平整邊緣的機(jī)床。Basedontheirpurposeconstructionnumberoftoolsthatcansimultaneouslybemounteddegreeofautomationlat

2、hesmeaccuratelylathetypemachinetoolscanbeclassifiedasfollows:根據(jù)它們的使用目的、結(jié)構(gòu)、能同時(shí)被安裝刀具的數(shù)量和自動(dòng)化的程度，車(chē)床—或更確切地說(shuō)是車(chē)床類(lèi)的機(jī)床，可以被分成以下幾類(lèi)：(1)Enginelathes(2)Toolroomlathes(3)Turretlathes(4)Verticalturningbingmills(5)Automaticlathes(6)Speci

3、alpurposelathes(1)普通車(chē)床(2)萬(wàn)能車(chē)床(3)轉(zhuǎn)塔車(chē)床(4)立式車(chē)床(5)自動(dòng)車(chē)床(6)特殊車(chē)床Inspiteofthatdiversityoflathetypemachinetoolstheyallhavecommonfeatureswithrespecttoconstructionprincipleofoperation.Thesefeaturescanbestbeillustratedbyconsideringt

4、hecommonlyusedrepresentativetypetheenginelathe.FollowingisadeionofeachofthemainelementsofanenginelathewhichisshowninFig.11.1.雖然車(chē)床類(lèi)的機(jī)床多種多樣，但它們?cè)诮Y(jié)構(gòu)和操作原理上具有共同特性。這些特性可以通過(guò)普通車(chē)床這一最常用的代表性類(lèi)型來(lái)最好地說(shuō)明。下面是關(guān)于圖11.1所示普通車(chē)床的主要部分的描述。Lathebed

5、.Thelathebedisthemainframeinvolvingahizontalbeamontwoverticalsuppts.Itisusuallymadeofgreynodularcastirontodampvibrationsismadebycasting.車(chē)床床身：車(chē)床床身是包含了在兩個(gè)垂直支柱上水平橫梁的主骨架。為減振它一般由灰鑄鐵或球墨鑄鐵鑄造而成。Ithasguidewaystoallowthecarriageto

6、slideeasilylengthwise.Theheightofthelathebedshouldbeappropriatetoenablethetechniciantodohisherjobeasilycomftably.它上面有能讓大拖板輕易縱向滑動(dòng)的導(dǎo)軌。車(chē)床床身的高度應(yīng)適當(dāng)以讓技師容易而舒適地工作。Headstock.Theheadstockisfixedatthelefthsideofthelathebedincludest

7、hespindlewhoseaxisisparalleltotheguideways(theslidesurfaceofthebed).Thespindleisdriventhroughthegearboxwhichishousedwithintheheadstock.主軸箱：主軸箱固定在車(chē)床床身的左側(cè)，它包括軸線平行于導(dǎo)軌的主軸。主軸通過(guò)裝在主軸箱內(nèi)的齒輪箱驅(qū)動(dòng)。Thefunctionofthegearboxistoprovidean

8、umberofdifferentspindlespeeds(usually6upto18speeds).Somemodernlatheshaveheadstockswithinfinitelyvariablespindlespeedswhichemployfrictionalelectricalhydraulicdrives.齒輪箱的功能是給主軸提供若干不同的速度(通常是6到18速)。有些現(xiàn)代車(chē)床具有采用摩擦、電力或液壓驅(qū)動(dòng)的無(wú)級(jí)調(diào)速主

9、軸箱。Thespindleisalwayshollowi.e.ithasathroughholeextendinglengthwise.Bar3thespindlethroughatrainofgears.Itisconnectedtoboththefeedrodtheleadscrewenablesingavarietyoffeedseasilyrapidlybysimplyshiftingtheappropriatelevers.現(xiàn)

10、代車(chē)床一般在主軸箱下裝備快速變換齒輪箱，通過(guò)一系列齒輪由主軸驅(qū)動(dòng)。它與光桿和絲桿連接，能容易并快速地通過(guò)簡(jiǎn)單轉(zhuǎn)換適當(dāng)?shù)牟僮鳁U選擇各種進(jìn)給。Thequickchangegearboxisemployedinplainturningfacingthreadcuttingoperations.Sincethatgearboxislinkedtothespindlethedistancethattheapron(thecuttingtool)t

11、ravelsfeachrevolutionofthespindlecanbecontrolledisreferredtoasthefeed.快速變換齒輪箱可用于普通車(chē)削、端面切削和螺旋切削作業(yè)中。由于這種齒輪箱與主軸相連，主軸每轉(zhuǎn)一圈溜板箱(和切削刀具)運(yùn)動(dòng)的距離能被控制，這距離就可以被認(rèn)為是進(jìn)給。LatheCuttingTools車(chē)床切削刀具Theshapegeometryofthelathetoolsdependuponthepur

12、posefwhichtheyareemployed.車(chē)床刀具的形狀和幾何參數(shù)取決于它們的使用目的。Turningtoolscanbeclassifiedintotwomaingroupsnamelyexternalcuttingtoolsinternalcuttingtools.Eachofthesetwogroupsincludethefollowingtypesoftools:車(chē)削刀具可以分為兩個(gè)主要組別，即外部切削刀具和內(nèi)部切削刀

13、具。這兩組中的每一組都包括以下類(lèi)型刀具：Turningtools.Turningtoolscanbeeitherfinishingroughturningtools.Roughturningtoolshavesmallnoseradiiareemployedwhendeepcutsaremade.車(chē)削刀具：車(chē)削刀具可以是精車(chē)刀具或粗車(chē)刀具。粗車(chē)刀具刀尖半徑較小，用于深切削。Ontheotherhfinishingtoolshavelar

14、gernoseradiiareusedfobtainingthefinalrequireddimensionswithgoodsurfacefinishbymakingslightdepthsofcut.Roughturningtoolscanberighthlefthtypesdependinguponthedirectionoffeed.Theycanhavestraightbentoffsetshanks.而精車(chē)刀具刀尖半徑較大，

15、用于通過(guò)微量進(jìn)刀深度來(lái)獲得具有較好表面光潔度的最終所需尺寸。粗車(chē)刀具按其進(jìn)給方向可以是右手型的或是左手型的。它們可以有直的、彎的或偏置的刀桿。Facingtools.Facingtoolsareemployedinfacingoperationsfmachiningplanesideendsurfaces.Therearetoolsfmachininglefthsidesurfacestoolsfrighthsidesurfaces.T

16、hosesidesurfacesaregeneratedthroughtheuseofthecrossfeedcontrarytoturningoperationswheretheusuallongitudinalfeedisused.端面刀具：端面刀具用在端面作業(yè)中加工平板側(cè)面或端部表面，也有加工左右側(cè)表面之分。與一般采用縱向進(jìn)給的車(chē)削作業(yè)相反，那些側(cè)表面通過(guò)采用橫向進(jìn)給產(chǎn)生。Cutofftools.Cutofftoolswhicha

17、resometimescalledpartingtoolsservetoseparatethewkpieceintopartsmachineexternalannulargrooves.切斷刀具：切斷刀具，有時(shí)也稱(chēng)為分割刀具，用于將工件分割成若干部分和或加工外部環(huán)形槽。Threadcuttingtools.Threadcuttingtoolshaveeithertriangularsquaretrapezoidalcuttingedge

18、sdependinguponthecrosssectionofthedesiredthread.Alsotheplaneanglesofthesetoolsmustalwaysbeidenticaltothoseofthethreadfms.螺紋切削刀具：螺紋切削刀具根據(jù)所需螺紋的橫截面，有三角形的、矩形的或梯形的切削刃。同時(shí)，這些刀具的平面角必須始終與螺紋形狀的平面角保持一致。Threadcuttingtoolshavestraigh

19、tshanksfexternalthreadcuttingareofthebentshanktypewhencuttinginternalthreads.車(chē)外螺紋的螺紋切削刀具為直刀桿，而車(chē)內(nèi)螺紋的螺紋切削刀具則是彎刀桿。Fmtools.Fmtoolshaveedgesespeciallymanufacturedtotakeacertainfmwhichisoppositetothedesiredshapeofthemachinedwk