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机械类毕业论文中英文对照文献翻译
机械类
毕业论文
中英文
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文献
翻译
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【机械类毕业论文中英文对照文献翻译】钻和镗,机械类毕业论文中英文对照文献翻译,机械类,毕业论文,中英文,对照,文献,翻译
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黄河科技学院毕业设计（文献翻译） 第 9 页 单位代码 02 学 号 080105058 分 类 号 TH6 密 级 毕业设计文献翻译院（系）名称工学院机械系专 业 名 称机械设计制造及其自动化学 生 姓 名李秋艳指 导 教 师贾百合2012年 03 月 10 日Northcott,W.H.A treatise on lathes and turning: simple, mechanical, and ornament-alM.London:Longmans,Green,2010:104-112.Drilling and boring(Excerpts)Flat articles are most conveniently driven by the face-plate,and long articles by the screwed chuck.The manner of attaching work to the former depends altogether upon the shape of the article,and no description will give an idea of all the methods employed.The operator will very frequently have to devise means for attaching his work,but this is not at all difficult.Any means may be employed that will not twist or strain the article,or in revolving come in the way of the lathe-bed or tools.A set of bolts of various lengths and with T-heads will be very useful,and a set of four of the clamps at Fig.129 are exceedingly convenient.In using these,the work is held against the face-plate and the bolts of the clamps are put into its most convenient slots.The small screw is adjusted so as to raise the end of each clamp,rather more than the thickness of the work off the face-plate,the large bolt being then tightened in all the four clamps,the work is pinched at four places between the face-plate and the ends of the clamps.It is generally necessary to bore holes as nearly as possible concentric with the rest of the work;for instance,when the article is a spur wheel or a pulley,it is necessary that the hole should be made concentric or true with the teeth of the wheel,or the face of the pulley;so that when the hole is made on driving the article,on a mandril the rim will run true,and will not require much to be turned off it,or more from one side than from another.When certain parts of articles have to remain unturned,it is a good plan to chuck the work true with those portions,without regarding those parts which have to be turned;so that ,when these points are rendered true by turning the whole article is nearly concentric.As the surface of the plate is quite true,it is evident that the surface of the article,or those points of the surface which are against the face-plate,will run true when the hole is bored and the work put on to the mandril.But there is no such guarantee that any part of the edge of the article will be true;it is therefore necessary,before tightening the bolts finally,to set the edge or rim true,in the same manner as when centering a piece of iron.That is,a piece of chalk is held against the work in motion,and,as those parts showing the chalk are the farthest from the centre,a tap with a hammer or mallet is given the article at those points,to drive them nearer the centre of the lathe.This is repeated until the chalk touches either all round,or at opposite points,when the clamp bolts may be tightened and the boring commenced.When articles have to be true with their inside edges,it is evident that this operation must be reversed.Wherever the chalk shows,those points must be hammered away from the centre.It is a difficult matter for one pair of hands to hold work against the face-plate whilst putting in the bolts for fastening it on in place.Workmen are in the habit of keeping it temporarily in place by forcing it against the face-plate by the boring bit or drill and the centre of the moving headstock.This practice cannot altogether be recommended,as,besides a direct tendency to damage the points of the drill and of the centre,it is a very frequent occurrence for the wholethe work and drill tocome down with a run on to the lathe-bed or to the ground;and this leads to serious damage to all things concerned,as the workman will readily admit if his toes happen to be between the work and the ground.Other more careful workmenif the work have a rough hole through it alreadyfasten the work temporarily to the face-plate by means of a bolt,screwing into the centre hole of the lathe-spindle,and a piece of straight iron with a hole through it,for a cross piece to span the hole.This practice is certainly all that can be desired,so far as both safety and convenience go;but it has one objectionthe screwing and unscrewing of this bolt are apt to damage or wear the centre hole,and cause the centre to fit slackly.Probably the best plan,when chucking heavy work,is,either to put a block of woo-d of the right height under the work,or to remove the face-plate from the lathe,and lay it horizontal,with its face upwards,when the work may be fastened to it with ease and convenience.When the work is properly chucked,it is set in motion,and the place where the hole is to be commenced should be trued up.The boring-rest is then put in place,just in front of the work;care being taken not to put it near enough for the bolts in revolving to strike against it.There are two holes in this boring-rest;onethe large oneis for the boring bits,the small one is for the drills.One of these holes is placed just opposite the centre of the work,and the proper drill or bit is put through it;the other end of the bits is furnished with a centre mark,into which the centre of the moving headstock must be placed,and the cutting edge of the drill forced into the revolving work,by moving the hand-wheel and forcing out the screw.The rectangular hole in the boring-rest only prevents the bit from revolving;besides this,it has to be kept steady,especially at the commencement of the hole.If the hole be a small one,the boring-wrench is put on over the drill,and the other end of the lever forced down by the workmans left hand.When the hole is a large one,the pressure thus obtained is not enough;but a larger lever of the same sort is then used,and a good heavy weight hung on to its end,and kept there whilst the bit is cutting its way through the hole.If the article be of wrought iron or steel,the cutting edge of the bit must be kept moist with soapsuds or soda-water;but with brass and cast-iron this is not required.In cutting large holes out of the solid,all the material cannot be removed by one instrument.A small drill must first be sent through,to be followed by a series of others,each taking an increasing cut,until the required size of the hole is nearly obtained,when the last bit should be carefully sent through;but it must not be made to take so heavy a cut as the bits preceding it.In taking a series of heavy cuts at the hole,the metal composing thearticle especially if cast-iron or brasswill be rendered rather hot by the friction;it is,therefore,a good plan to allow the article to cool before passing through the finishing or last bit.If this be not done,and the hole is finished whilst the surrounding metal is hot,it will be found that when the metal has cooled,the finishing bit is unable to enter again owing to the contraction of the metal.It may,however,happen that the spindle to work into the hole has been made rather under the standard size.In this case it will be advisable to take advantage of this expansion and contraction of the metal,and make it subservient to our purpose,by boring the last cut but one with a dull bit,and taking a heavy cut.The metal will then be made very hot and the hole will expand;so that if the finishing bit be then quickly passed through the result will be that when the metal cools the hole will again contract,and form a closer fit with the spindle previously turned too small.These little facts are small in themselves;but,by bearing them in mind,they may frequently be turned to useful account.It is scarcely necessary to observe that,in all cases,care must be taken not to exceed a certain heat,or to allow the work to get hot enough to lower the temper of the tool.Long cylindrical or other shaped articles,through which a hole is required,cannot be conveniently attached to the face-plate;and therefore,for these articles,the screwed or bell-chuck, Fig.121,is used.The chuck being put on the lathe-spindle,the article is inserted between the screws,which are then screwed down to encompass and tightly hold it.The beginner will,probably,have some little difficulty in adjusting these screws so as to hold the work true;but the matter is much simplified by trueing the inside set of screws first,and afterwards adjusting the outside ones.These screws should be set down tight enough to prevent the article slipping or moving about;but if when the hole is made the material will be thin,care should be taken not to set the screws down tighter than necessary,as otherwise the metal will be compressed,and the hole rendered out of shape in their neighbourhood.When the articles to be drilled are too long for this chuck alone,the ends are turned up true for an inch or two;and one end is then chucked true,and held between the outside set only of the screws of the chuck,whilst the other end is supported by being run in the die-stay.This is fastened to the lathe-bed,at the proper place,and a wooden or metal bearing,having a hole the same size as the end of the work,is put into the Vs,and adjusted so as to bring the centre of the work in the line of lathe-centres.The lathe is then set in motion,and the hole drilled in the usual manner.For these long articles the best tool I know of is the D-bit,shown at Fig.124.This tool is not half so much used as it ought to be,and,when used it is in conjunction with several other drills,and in such a roundabout manner that very few have patience to use it at all.These other drills are,however quite unnecessary after the D-bit is once started.The best manner of proceeding is as follows:First,place the boring-rest in position,and with an ordinary drill,of the same size as the D-bit,drill out a recess about 1/8 or 1/4 of an inch in depth;remove the boring-rest,place the centre mark at the end of the D-bit,against the centre of the headstock,and screw up carefully until the drill is in-to cut;the hole may then be bored through with ease and the certainty of its being true.The drill must be kept well lubricated with soda-water and oil,and occasionally removed,and the hole cleared of shavings.If the hole be more than a foot long,it will be better to drill it half from each end;and,if great truth be required,two of these drills should be used as in the other cases,As in long holes it is rather difficult to keep drills well moistened,the workman will find it a good plan to have a small syringe,and inject or squirt the lubricant into the hole with force;by so doing,not only will the drill be kept wet,but the shavings will,in a great measure,be washed out and the hole cleared.On comparing the D form of drill with others,it will be found that the cutting edge is only equal to half the diameter of the hole;at the same time the drill stem is strong and well able to stand torsional strain,to which drills are mostly subject.In the ordinary drill,the cutting edge is equal to about one and a half diameters of the hole,whilst the stem is not nearly so well calculated to bear the strain.It therefore appears reasonable to conclude that the D-bit is better adapted than the others to cut a long hole out of the solid,or indeed to cut a long hole out at all;and this is found to be the case.I have had considerable practice with this drill,and have so much confidence in its powers that I would undertake,with it alone,to drill a one-inch hole through a shaft thirty or forty feet long.Holes required to be very smooth and straight,or require to be very slightly enlarged,are ground on a lead or copper lap,Fig.128.Also in the of articles which have been hardened or case hardened,the action of the fire is sure to have had a effect upon the hole.In some cases the hole is bent;in others,the surface is rather blistered;in all cases it is rendered somewhat rough.All imperfections are removed by grinding the hole on a lap.The method of using these laps is very simple:they are put between the lathe-centres,and driven by a lathe-carrier in the ordinary way.The lapssurface is covered with a coat of fine emery powder and oil;the former may be caused to stick to the lead by being slightly forced into it by a few taps with a hammer.The hole is then put on the lap,which is set in rapid rotation,and the article moved up and down;and,being prevented from moving around with the lap,the inside of the hole is ground by the adhering emery.The emery and oil must be continually replenished,and the surface of the lap kept moist with it,as,if allowed to get dry,the two surfaces will bind or cling to each other,and abrasion will result.If the article be heavy,precaution should be taken of turning it over,so as to grind every portion of the hole alike;otherwise the weight of the article,pressing all on one side of the hole,will cause it to be ground more on that side than the others,and the hole will be rendered non-circular.Care must also be taken to keep the middle of the lap well supplied with emery,and not to grind one end or the two ends of the hole larger than the middle.This,however,is a very common occurrence,and requires some little address to get over.Where practicable,it is also advisable to reverse the direction the lathe occasionally,as sometimes,in lapping out a hole,the hole will draw itself onwards,and the workmans whole force will be insufficient to prevent its tightening itself on and binding.In this case,the best way is to either let the work go around with the lap,and to immediately stop the lathe and drive the work back with a mallet before it gets cool and contracts firmly on to the lap;or to reverse the direction of the lathe,when the hole will generally run back of its own accord,unless it is gone on too far and become tight.It is sometimes a very difficult matter to get work off a lap when the grinding surfaces have allowed to get dry and to abrade themselves.威廉亨利诺斯考特.论车床和车削：简单，机械，装饰M.伦敦：朗文公司，2010:104-112.钻和镗（摘录）平的制品最方便的驱动是通过面板，长的制品用螺纹卡盘。连接方式的操作完全取决于之前制品的形状,也没有说明能为所有使用的方法提供意见。操作员会非常频繁地去想办法来维持他的操作,虽然这一点也不难。可采用任何的方式都不能让制品扭曲或变形，或者旋转时阻碍车床和工具。一组不同长度和T型头螺栓将是非常有用的，和一套有四个的夹具(如图.129)极其方便。用了这些，操作时可以很方便地把面板和夹具上的螺栓的放进一个插槽里。小的螺丝进行调整，以提高每个夹具，而不是减小面板厚度，用大螺栓来紧固这四个夹具，操作是在面板中的四个地方和夹具的末端进行拧紧。一般而言,通常需要尽可能在跟其余的操作同心的地方钻孔，比如，工件时正齿轮和皮带轮时，很有必要钻同心孔或跟轮齿和齿面一样，只有这样，当孔是用来驱动工件时，在顶杆上才不会跑偏，这样也不需要多次停车，或者出现一边多一边少。当工件的某一部分必须保持不能转动，这是一个很好的计划来检查这些部分的操作是否正确，不考虑这其中哪部分是必须转动的，因此，当这些点都能通过车削加工整个工件都能正确呈现就接近同心了。由于板材的表面是真的，这在制品的表面显而易见，表面上的这些点不利于面板，如果跑正了，就可以钻孔并且工件可放在机床心轴上。但是不能保证制品所有的边缘部分都会如此。所以有必要先拧紧螺栓，设置边缘安置正确，同样的方法也适合定一块铁的中心。一支粉笔可以针对运动中的工件，在这些零件上可以看出粉笔离中心很远，用锤子或木槌可以在工件上敲定这些点，来驱动他们接近车床中心。重复这些操作直到粉笔和所有圆相切，或相反的点，当夹紧螺栓收紧就可以开始钻了。工件的内壁边缘必须是安装正确的时候，就证明这个操作需要调换。无论粉笔怎样显示，这些点必须锤的远离中心。这是一个困难的问题来用一只手拿着工件，把它放在面板上还时时地用螺栓把它紧固到位。工作人员人们都习惯把它暂时到位，迫使它在面板上和床头箱的中心通过钻头钻孔。这种操作不被完全建议，当然，除了能直接损坏钻的顶点和中心之外，整体来说这是经常发生的工件和钻头凭借床身和地面降下来；这可以导致一系列有关的东西损坏，尽管工作人员很乐意承认如果他的脚趾碰巧在工件和地面之间。其他一些比较认真的工作人员如果工件有一个粗糙的孔通过暂时把工件通过螺栓紧固到面板上，拧到车床主轴的中心孔上，或用一个有孔的直角铁穿起来，用十字块跨过孔。这些实践可以完全想到，安全便捷同样可以达到；但是有一个缺点该螺栓的拧紧和松开容易损坏或磨损中心孔，并使中心配合松动。也许最好的方案就是，当夹紧重型工件时，或者用一个木块在放在工件下的合适的高度，或者是把面板移出车床，把它水平放置，把面朝上，这样工件就能轻松方便地紧固了。当工件正确地夹紧，它开始运动，孔开始的地方应该被装正。钻台被放置就位，就在工件的前面，小心地放置不要让旋转的螺栓撞击到它。钻台上有两个孔；其中大的一个是放镗块的，小的那个是放钻头的。这其中的一个空是位于工件中心的另一面，合适的镗刀和钻可以通过它，镗刀的另一端配有一个中心标志，必须放置运动的主轴承的轴心，钻子的切削边缘被迫进入旋转的工件，通过移动手轮挤出螺丝。钻台上的矩形孔不仅可以防止钻头旋转；还可以保持稳定，特别是开始的孔。如果孔是小的，钻床扳手可以放在钻头上，扳手的另一边可以通过工人的左手用力向下。如果孔是大的，由此获得的压力是不够的；但同样性质的大扳手就可以用了，用重物挂在一端，并保持同样切割的方式穿过孔。如果制品是熟铁或钢，尖端位必须保持湿润，用肥皂水或苏打水;但对于黄铜和铸铁这不是必需的。用大孔切割出来的固体，所有材料都不能用一个工具去除。必须先通过小钻，再通过一系列的其他钻，每次增加进给量，直到得到所需孔的尺寸接近，当最后一点尺寸应仔细进给；但它不能采取那么重的切削像钻头在她前面一样。孔进行了一系列很大的切削，金属的构成工件特别是铸铁和黄铜经过摩擦会变得相当热；因此一个好的方案应允许工件在通过完成或最后钻孔之前冷却。如果不能达到，在孔完成的同时周围的金属就变得很热了，我们会发现，当金属冷了之后，由于金属的收缩，精加工的钻头就不能再次进入了。也许，可能会发生这种情况，如果钻床强插进空里，会使孔小于标准尺寸。这种情况，通常被建议合理地利用金属的伸缩性，使它有助于我们的目的，通过最后的钻削是用比较钝的刀具，进行大的切削。金属就会变得很热，孔也会扩张；所以
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