1850_3缸發(fā)動機飛輪殼組合鉆床主軸箱設計
1850_3缸發(fā)動機飛輪殼組合鉆床主軸箱設計,_3,發(fā)動機,飛輪,組合,鉆床,主軸,設計
單位代碼 02 學 號 080105058 分 類 號 TH6 密 級 畢業(yè)設計文獻翻譯院 ( 系 ) 名 稱 工 學 院 機 械 系專 業(yè) 名 稱 機 械 設 計 制 造 及 其 自 動 化學 生 姓 名 李 秋 艷指 導 教 師 賈 百 合2012 年 03 月 10 日黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 1 頁 Northcott,W.H.A treatise on lathes and turning: simple, mechanical, and ornament-al[M].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 黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 2 頁 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 whole—the work and drill to—come 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 workmen—if the work have a rough hole through it already—fasten 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 objection—the 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;one—the large one—is 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 黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 3 頁 the workman's 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 the—article especially if cast-iron or brass—will 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.黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 4 頁 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 V's,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.黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 5 頁 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 laps'surface 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 workman's 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·諾斯考特.論車床和車削:簡單,機械,裝飾[M].倫敦:朗文公司,黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 6 頁 2010:104-112.鉆和鏜(摘錄)平的制品最方便的驅(qū)動是通過面板,長的制品用螺紋卡盤。連接方式的操作完全取決于之前制品的形狀,也沒有說明能為所有使用的方法提供意見。操作員會非常頻繁地去想辦法來維持他的操作,雖然這一點也不難。可采用任何的方式都不能讓制品扭曲或變形,或者旋轉(zhuǎn)時阻礙車床和工具。一組不同長度和 T 型頭螺栓將是非常有用的,和一套有四個的夾具 (如圖.129)極其方便。用了這些,操作時可以很方便地把面板和夾具上的螺栓的放進一個插槽里。小的螺絲進行調(diào)整,以提高每個夾具,而不是減小面板厚度,用大螺栓來緊固這四個夾具,操作是在面板中的四個地方和夾具的末端進行擰緊。一般而言,通常需要盡可能在跟其余的操作同心的地方鉆孔,比如,工件時正齒輪和皮帶輪時,很有必要鉆同心孔或跟輪齒和齒面一樣,只有這樣,當孔是用來驅(qū)動工件時,在頂桿上才不會跑偏,這樣也不需要多次停車,或者出現(xiàn)一邊多一邊少。當工件的某一部分必須保持不能轉(zhuǎn)動,這是一個很好的計劃來檢查這些部分的操作是否正確,不考慮這其中哪部分是必須轉(zhuǎn)動的,因此,當這些點都能通過車削加工整個工件都能正確呈現(xiàn)就接近同心了。由于板材的表面是真的,這在制品的表面顯而易見,表面上的這些點不利于面板,如果跑正了,就可以鉆孔并且工件可放在機床心軸上。但是不能保證制品所有的邊緣部分都會如此。所以有必要先擰緊螺栓,設置邊緣安置正確,同樣的方法也適合定一塊鐵的中心。一支粉筆可以針對運動中的工件,在這些零件上可以看出粉筆離中心很遠,用錘子或木槌可以在工件上敲定這些點,來驅(qū)動他們接近車床中心。重復這些操作直到粉筆和所有圓相切,或相反的點,當夾緊螺栓收緊就可以開始鉆了。工件的內(nèi)壁邊緣必須是安裝正確的時候,就證明這個操作需要調(diào)換。無論粉筆怎樣顯示,這些點必須錘的遠離中心。這是一個困難的問題來用一只手拿著工件,把它放在面板上還時時地用螺栓把它緊固到位。工作人員人們都習慣把它暫時到位,迫使它在面板上和床頭箱的中心通過鉆頭鉆孔。這種操作不被完全建議,當然,除了能直接損壞鉆的頂點和中心之外,整體來說這是經(jīng)常發(fā)生的——工件和鉆頭——憑借床身和地面降下來;這可以導致一系列有關(guān)的東西損壞,盡管工作人員很樂意承認如果他的腳趾碰巧在工件和地面之間。黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 7 頁 其他一些比較認真的工作人員——如果工件有一個粗糙的孔通過——暫時把工件通過螺栓緊固到面板上,擰到車床主軸的中心孔上,或用一個有孔的直角鐵穿起來,用十字塊跨過孔。這些實踐可以完全想到,安全便捷同樣可以達到;但是有一個缺點——該螺栓的擰緊和松開容易損壞或磨損中心孔,并使中心配合松動。也許最好的方案就是,當夾緊重型工件時,或者用一個木塊在放在工件下的合適的高度,或者是把面板移出車床,把它水平放置,把面朝上,這樣工件就能輕松方便地緊固了。當工件正確地夾緊,它開始運動,孔開始的地方應該被裝正。鉆臺被放置就位,就在工件的前面,小心地放置不要讓旋轉(zhuǎn)的螺栓撞擊到它。鉆臺上有兩個孔;其中大的一個是放鏜塊的,小的那個是放鉆頭的。這其中的一個空是位于工件中心的另一面,合適的鏜刀和鉆可以通過它,鏜刀的另一端配有一個中心標志,必須放置運動的主軸承的軸心,鉆子的切削邊緣被迫進入旋轉(zhuǎn)的工件,通過移動手輪擠出螺絲。鉆臺上的矩形孔不僅可以防止鉆頭旋轉(zhuǎn);還可以保持穩(wěn)定,特別是開始的孔。如果孔是小的,鉆床扳手可以放在鉆頭上,扳手的另一邊可以通過工人的左手用力向下。如果孔是大的,由此獲得的壓力是不夠的;但同樣性質(zhì)的大扳手就可以用了,用重物掛在一端,并保持同樣切割的方式穿過孔。如果制品是熟鐵或鋼,尖端位必須保持濕潤,用肥皂水或蘇打水;但對于黃銅和鑄鐵這不是必需的。用大孔切割出來的固體,所有材料都不能用一個工具去除。必須先通過小鉆,再通過一系列的其他鉆,每次增加進給量,直到得到所需孔的尺寸接近,當最后一點尺寸應仔細進給;但它不能采取那么重的切削像鉆頭在她前面一樣??走M行了一系列很大的切削,金屬的構(gòu)成——工件特別是鑄鐵和黃銅——經(jīng)過摩擦會變得相當熱;因此一個好的方案應允許工件在通過完成或最后鉆孔之前冷卻。如果不能達到,在孔完成的同時周圍的金屬就變得很熱了,我們會發(fā)現(xiàn),當金屬冷了之后,由于金屬的收縮,精加工的鉆頭就不能再次進入了。也許,可能會發(fā)生這種情況,如果鉆床強插進空里,會使孔小于標準尺寸。這種情況,通常被建議合理地利用金屬的伸縮性,使它有助于我們的目的,通過最后的鉆削是用比較鈍的刀具,進行大的切削。金屬就會變得很熱,孔也會擴張;所以,如果黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 8 頁 最后的切削很快的通過,那么結(jié)果就是當金屬變冷了之后孔會再度收縮,之前形成的與主軸緊密配合會變得很小。這些小的事實本身也很小;但是,把它記在心里,時常會變成很有用的數(shù)據(jù)。這是幾乎沒有必要指出,在所有情況下,必須注意不能超過一定的熱,或允許工件得到足夠的熱能降低工具的溫度。長圓筒形或其他形狀的物品,需要通過一個洞,可以方便地附著在面板上;因此,對于這些制品,螺紋或鐘形夾頭,如圖 121 中使用的。夾頭被放在車床主軸上,制品之間插入螺絲,然后擰緊直到環(huán)繞并緊緊握住它。初學者,也許會在調(diào)整這些螺絲以致工件安裝正確上有一些小困難,但這個問題可以通過首先正確安裝內(nèi)置的螺絲,然后調(diào)整外面的來簡化。這些螺釘應擰的足夠緊,防止物品滑動或移動;但是如果孔是由薄的材料制成的,應注意不要把螺絲擰得比需要的還緊,否則金屬將被壓縮,并會比周圍材料變形。當工件用單獨的卡盤被鉆太長了,末端會露出來一兩英寸;一端是正確夾緊,夾在外部設置的螺紋卡盤之間,同時另一端由正在運行的模具支撐。和一個木制或金屬的軸承在一個合適的地方固定在車床床身,有一個跟工件一端尺寸相同的孔,放在 V's 里,調(diào)整工件的中心跟車床中心在一條線上。車床是在運動,用通常的方式鉆孔。我知道的這些加工這些制品的罪好的工具地 D 號鉆頭,如圖 121。這個工具沒有它應當做的那么有用,并且是連同其他鉆頭一起用的,并采用的迂回方式,很少有耐心去使用它。其他的刀具可以使用,所以很沒有必要再啟動 D 號鉆頭。(一旦啟動 D 號鉆頭就沒必要再使用其他刀具)最好的方式進行如下:第一,把鉆臺用和 D 號鉆頭尺寸一樣的普通鉆頭放置好,鉆一個約 1 /8 或 1 /4 英寸深度的凹槽,移動鉆臺,在 D 號鉆頭的末端和主軸承的另一端做上標記,小心擰緊直到鉆頭接近車削的部分;然后可以通過鉆孔的輕松和確定它安裝正確。鉆頭必須用蘇打水和油保持良好潤滑,不定期的清理,并清理孔周圍的切屑。如果孔超過一英尺長,最好能在兩頭鉆;如果精確性能滿足要求,在其他情況中可以使用兩個相同的刀具。如在鉆長孔時很難保持鉆頭濕潤,工作人員會發(fā)現(xiàn)使用注油器是個很好的辦法,用力注入或噴射潤滑油進入孔內(nèi),這樣做,不僅保持鉆頭濕潤,還是很好的措施把孔內(nèi)的切屑清理出來。D 號鉆頭跟其他鉆頭相比,你會發(fā)現(xiàn),它切削的刀刃只相當于直徑孔的一半,同時強大的鉆桿可以抵擋扭轉(zhuǎn)應變,鉆頭是主要問題。在普通鉆床,切割邊緣大約等于黃 河 科 技 學 院 畢 業(yè) 設 計 ( 文 獻 翻 譯 ) 第 9 頁 一個半直徑的孔,同時鉆桿也不能承受計算中的那么大的應力。因此,得出這樣一個結(jié)論,D 號鉆頭比其他鉆頭能更好地適用于切削一個固體長孔,或確實把一個長孔鉆好;是發(fā)現(xiàn)有這種情況的。我已經(jīng)用這種鉆頭進行了大量的試驗,并且很有信心,我敢擔保,通過三十英寸或四十英尺的軸去鉆一個一英尺長的孔??滓笫欠浅9饣街?,或允許非常輕微的擴大,基于一個鉛或銅圈,如圖128。一個滲碳硬化或表面硬化的工件,淬火時為了確保對孔有一個影響。在許多情況下孔都會彎曲;另外,表面是比較氧化的;總的情況,它還是多少會有些彎曲的。所有的殘次品通過在圈上研磨來篩出來。使用這些圈的方法很簡單:它們放在車床中心之間,用一般的方法通過車載驅(qū)動,圈的表面覆蓋一層金剛砂粉和油;前者可能通過一點力量用錘子輕敲幾下粘在鉛上。然后把孔放在急速旋轉(zhuǎn)的圈上,工件會上下移動;不能和圈一起移動,孔的里面被金剛砂包圍。金剛砂和油必須持續(xù)填滿,圈的表面必須保持濕潤,如果允許干燥,兩個表面會結(jié)合或相互緊貼,將導致磨損。如果工件是沉重的,應把它翻過來采取預防措施,磨削每一部分都采取同樣的措施;否則工件的重量壓在孔的一側(cè),會導致磨損的一邊比領(lǐng)一邊多,并且孔也會變成非圓形。還必須注意保持中間的圈很好的提供金剛砂,而不是磨削的一端或兩端孔大于中間孔。然而,這是一個非常普遍的現(xiàn)象,并且需要在一些小的地方去恢復。在可行的情況下,間或扭轉(zhuǎn)車床方向也是可行的,有時,研磨出一個孔,孔會拖動本身本身向前,工人的全部力量也不足以防止其自身的緊縮和粘合。在這種情況下,最好的方法就是讓工件在圈周圍繞一圈,并且立即停車用錘子在工件冷卻和圈收縮緊固之前把工件打出來,除非工件走的太遠或者已經(jīng)緊固。有時把工件從已經(jīng)磨削得到干燥的圈中清理出來還不擦傷工件是很困難的事情。
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