专业英语作业3.doc

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1、陕西航空职业技术学院2010〜2011学年第二学期《机电专业英语》结课作业班级：09572学号：27姓名:H玉龙成绩：1.将给定的英文材料抄写在下边，然后翻译成汉语。modularfixturingoftenisusedforsmallormoderatelotsizesespeciallywhenthecostofdedicatedfixturesandthetimerequiredtoproducearediffculttojustifycomplexworkpiecescanbelocatedwithinmachinesthroughfixturesprod

2、ucedquicklyfromstandardcomponentsandcanbedisassembledwhenaproductionruniscompletedmodularfixturesusuallyarebasedontoolingplatsorblocksconfiguredwithgridholesorT-slotsuponwhichafixturesisconstructedAnumberofotherstandardcomponents(suchaslootingpins,adjustablestops,workpiecesupports,V-b

3、locks,clampsandsprings)canbemountedontothebaseplateorblocktoquicklyproduceafixturescanbeassembledandmodifiedusingindustrialrobotsAScomparedwithdedicatedfixtures,modularfixturinghasbeenshowntobelowincost,haveashorterleadtimeeasiertorepairdamagedcomponents,andpossessmoreintrinsicflexibi

4、lityofapplicationBED-of-nailsdevicethisfixturesconsistsofaseriesofair-actuatedpinsthatconformtotheshapeoftheexternalsurfacesofthepartEachpinmovesasnecessarytoconformtotheshapeatitspointofcontactwiththepartthepinsarethenmechanicallylockedagaintthepart.thedeviceisconpact,hashighstiffnes

5、s,andisconfigurableAdjustable-forceclamingthestraingagemountedontheclampsensesthemagniiudeoftheclampingforcethesystemthenadjuststhisforcetokeeptheworkpiecesecurelyclampedtotheworkpiecefortheparticularapplicationItalsocanpreventexcessiveclampingforcethatotherwisemaydamagethewrokpiecesu

6、rfaceparticularlyifitissoftorslenderPhase-changematerialstherearetwomethodsthatcanholdirregular-shapedorcurvedworkpieceinamediumotherthanhardtoolinginthefirstandoldermethod』low-melting-pointmetalisusedastheclampingmediumForexample,anirregurar-shapedworkpieceisdippedintomoltenleadandal

7、lowedtoset(likethewoodenstickinapopsicle-aprocesssimliartoinsertmolding)Aftersetting,thesolifiedleadblockisclampedinasimplefixturethepossiblyadverseeffectofsuchmaterialsasleadontheworkpiecetobeclamped(liquid-metalembrittlement)mustconsideredinthesecondmethod,thesupportingmediumisamagn

8、etorb