機(jī)械外文翻譯--普通全鋼沖模的沖壓精度分析

1、<p><b>　　外文文獻(xiàn)資料</b></p><p>　　General all-steel punching die’s punching accuracy</p><p>　　General all-steel punching die’s punching accuracy</p><p>　　Accuracy of pan

2、el punching part is display the press accuracy of the die exactly. But the accuracy of any punching parts’ linear dimension and positional accuracy almost depend on the blanking and blanking accuracy,. So that the compou

3、nd mould of compound punching’s accuracy, is typicalness and representation in the majority.</p><p>　　Analyse of the die’s accuracy </p><p>　　For the analyse of pracyicable inaccuracy during pro

4、duction of dies to inactivation, we could get the tendency when it is augmentation in most time. From this we could analyse the elements. When the new punch dies pt into production to the first cutter grinding, the inacc

5、uracy produced called initial error; if the die grinding more than twenty times, until it’s discard, the inaccuracy called conventional error; and before the dies discard, the largest error of the last batch permit, call

6、ed limit</p><p>　　The initial error usually is the minimal through the whole life of die. Its magnitude depend on the accuracy of manufacture, quality, measure of the punching part, thickness of panel, magni

7、tude of gap and degree of homogeneity. The accuracy of manufacture depend on the manufacture process. For the 1 mm thicked compound punching part made in medium steel, the experimental result and productive practice all

8、prove that the burr of dies which produced by spark cutting are higher 25%~~30% than produc</p><p>　　The normal error of the punch die is the practicable error when the fist cutter grinding and the last cutt

9、er grinding before the die produce the last qualified product. As the increase of cutter grinding, caused the measure the nature wear of the dies are gradual increasing, the error of punching part increase also, so the p

10、arts are blew proof. And the die will be unused. The hole on the part and inner because the measure of wear will be small and small gradually, and its outside form will be la</p><p>　　The limit error in punc

11、hing parts are the max dimension error which practicable allowed in the parts with limit error. This kind of parts usually are the last qualified products before the die discard.</p><p>　　For the all classes

12、 of dies, if we analyse the fluctuate, tendency of increase and decrease and law which appeared in the die’s whole life, we will find that the master of the error are changeless; the error that because the abrade of the

13、cutter and impression will be as the cutter grinding times increased at the same time. And that will cause the error oversize gradually; and also have another part error are unconventional , unforeseen. Therefore, every

14、die’ s error are composed of fixed error,</p><p>　　1. fixed error </p><p>　　At the whole process when the New punching die between just input production to discard, the changeless master error t

15、hat in qualified part are called fixed error. It’s magnitude is the deviation when the die production qualified products before the first cutter grinding. Also is the initial error, but the die have initial punching accu

16、racy at this time. Because of the abrade of parts, the die after grinding will be change the dimension error. And the increment of deviation will oversize as the </p><p>　　(1) the material , sorts, structure

17、, (form) dimension, and thick of panel</p><p>　　the magnitude of punching gap and degree of homogeneity are have a important effect for the dimension accuracy. Different punching process, material, thick of

18、panel, have completely different gap and punching accuracy. A gear H62 which made in yellow brass with the same mode number m=0.34, 2mm thick and had a center hole, when the gap get C=0.5%t (single edge) , and punched wi

19、th compound punching die, and the dimension accuracy reached IT7, the part have a flat surface ,the verticality of tangen</p><p>　　(2) punching craft and molder structure type</p><p>　　Uses the

20、different ramming craft, flushes a precision and the fixederror difference is really big. Except that the above piece gearexample showed, the essence flushes the craft and ordinary punching flushes a precision and the fi

21、xed error differs outside a magnitude,even if in ordinary punching center, uses the different gap punching, thefixed error difference very is also big. For example material thickt=1.5mm H62 brass punching, selects C <

22、= the 40%t unilateral I kind ofsmall gap punching comp</p><p>　　(3) the craft of punching die’s manufacture</p><p>　　the main work of punching die namely are raised, the concave moldprocessing p

23、rocedure, to operates on the specification not to behigh, can time form a more complex cavity. But its processing surfaceapproximately is thick > 0.03 ~ 0.05mm is the high temperatureablation remaining furcated austen

24、ite organization, degree ofhardness may reach as high as HRC67 ~ 70, has the micro crack, easilywhen punching appears broke the cutter or flaking. The Italian CorradaCorporation''s related memoir called "th&

25、lt;/p><p>　　With precisely rubs truncates the law manufacture punching die, specially makes the high accuracy, the high life punching die, such as: Thin material small gap compound punching die, multi- location

26、s continuous type compound die and so on, has the size precision high, the work component smachined surface roughness Ra value is small, the mold life higher characteristic. Its processing craft at present changed the el

27、ectrical fire by the past ordinary engine bed rough machining spark cutting or the</p><p>　　(4) gap size and degree of homogeneity </p><p>　　the flange and other sheet forming sgene rally all mu

28、st first punching (fall material) the plate to launch the semi finished materials, after also has the forming to fall the material, the incision obtains the single end product to flush. Therefore punching the work, inclu

29、ding is commonly used punching hole, the margin, cut side and so on, regarding each kind of sheet pressing partall is necessary. Therefore punching the gap to flushes a out form in chprecision to have the decisive influe

30、nce. pu</p><p>　　(5) ramming equipment elastic deformation In the ramming process </p><p>　　After the punch press load bearing can have the certain elastic deformation. Although this kind of dis

31、tortion quantity according to flushes the pressure the size to change also to have the obvious directivity, but on the pressing part, mainly is to has the volume ramming archery target stamping, embosses, the equalizatio

32、n, the pressure is raised, the wave, flushes crowds, the shape, the flange, hits flatly, thinly changes draw ability and so on the craft work punching forming flushes, has the si</p><p><b>　　外文譯文</b

33、></p><p>　　普通全鋼沖模的沖壓精度分析</p><p>　　沖壓零件的精度是面板顯示媒體模具的精度完全正確。但其準(zhǔn)確性的沖壓零件的尺寸和位置精度線性幾乎取決于沖裁下料精度。所以復(fù)合模具的復(fù)合沖壓的準(zhǔn)確性在普通沖壓的眾多種類與不同結(jié)構(gòu)的沖模中，最具典型性和代表性。</p><p><b>　　沖模的沖壓精度分析</b></

34、p><p>　　對沖模投產(chǎn)至失效報(bào)廢各個(gè)時(shí)期沖件的實(shí)際誤差分析，可以看出其增大的時(shí)期及趨向，從而分析其增大的因素。新沖模投產(chǎn)至第一次刃磨前沖制沖件的誤差即所謂的初始誤差；沖模經(jīng)過20次左右刃磨至失效報(bào)廢前沖制的沖件誤差稱之為常規(guī)誤差；而沖模失效報(bào)廢前沖制的最后一批合格沖件的允許最大誤差稱之為極限誤差。在現(xiàn)場，確定沖模刃磨壽命的依據(jù)是沖件沖孔與落料的毛刺高度。由于任何成形件都具有沖裁作業(yè)（毛坯落料或沖孔），對于復(fù)合模尤

35、為如此。所以，沖件毛刺高度的觸模檢查和測量并按企業(yè)標(biāo)準(zhǔn)或JB4129-85《沖壓件毛刺高度》對照檢測就顯得十分重要。</p><p>　　沖模的初始誤差通常是沖模整個(gè)壽命中沖件誤差最小的。其大小主要取決于沖模的制造精度與質(zhì)量及沖件尺寸、料厚以及間隙值大小與均勻度。沖模的制造精度及質(zhì)量又取決于制模工藝。對于料厚t≤1mm的中碳鋼復(fù)合沖裁模沖件，實(shí)驗(yàn)結(jié)果與生產(chǎn)實(shí)踐都證明，電火花線切割制造的沖模沖件毛刺高度比用成型磨或

36、NC與CNC連續(xù)軌跡座標(biāo)磨即精密磨削工藝制造的沖模沖件要高25%～30%。這是因?yàn)楹笳卟粌H加工精度高，而且加工面粗糙度Ra值要比前者小一個(gè)數(shù)量級，可達(dá)到0.025μm。因此，沖模的制造精度與質(zhì)量等因素決定了沖模的初始沖壓精度，也造就了沖件的初始誤差。</p><p>　　沖件的常規(guī)誤差是沖模經(jīng)第一次刃磨到最后一次刃磨后沖出最后一個(gè)合格沖件為止，沖件實(shí)際具有的誤差。隨著刃磨次數(shù)的增加，刃口的自然磨損而造成的尺寸增量

37、逐漸加大，沖件的誤差也隨之加大。當(dāng)其誤差超過極限偏差時(shí)，沖件就不合格，沖模也就失效報(bào)廢。///////沖件上孔與內(nèi)形因凸模磨損尺寸會逐漸變??；其外形落料尺寸會因凹模磨損而逐漸增大。所以，沖件上孔與內(nèi)形按單向正偏差標(biāo)允差并依接近或幾乎等于極限最大尺寸制模。同理，沖件外形落料按單向負(fù)偏差標(biāo)注允差并依接近或幾乎等于極限最小尺寸制模。這樣就使沖件的常規(guī)誤差范圍擴(kuò)大，沖?？扇心ゴ螖?shù)增加，模具壽命提高。</p><p>　　

38、沖件的極限誤差是具有極限偏差的沖件所具有的實(shí)際允許的最大尺寸誤差。這類沖件通常是在沖模失效報(bào)廢前沖制的最后一批合格沖件。</p><p>　　對各類沖模沖件誤差在沖模整個(gè)壽命中出現(xiàn)的波動(dòng)、增減趨向及規(guī)律等進(jìn)行全面分析便可發(fā)現(xiàn)：沖件誤差的主導(dǎo)部分是不變的；因刃口或型腔的自然磨損而出現(xiàn)的誤差增量隨沖模刃磨沖數(shù)增加而使這部分誤差逐漸加大；還有部分誤差的增量是非常規(guī)的、不可預(yù)見的。所以，各類沖模沖件誤差是由因定誤差、漸增

39、誤差、系統(tǒng)誤差及偶發(fā)誤差等幾部分綜合構(gòu)成。</p><p><b>　　1、固定誤差</b></p><p>　　新沖模在指定的沖壓設(shè)備上投入使用至失效報(bào)廢的整個(gè)（總）壽命過程中，其合格沖件誤差的主導(dǎo)部分固定不變即所謂固定誤差。其大小就是新沖模第一次刃磨前沖制的合格沖件的偏差，也即沖模的初始誤差，而此時(shí)的沖模具有初始沖壓精度。刃磨后的沖模，因其工作零件（凸、凹模）磨損

40、而改變尺寸誤差，使沖件識差增量隨刃磨次數(shù)增加而逐漸加大，故沖模刃磨后的沖壓精度亦稱“刃磨精度”比其初始精度要低。沖模沖件的固定誤差取決于以下各要素：</p><p>　?。?）沖件的材料種類、結(jié)構(gòu)（形狀）尺寸及料厚</p><p>　　沖裁間隙的大小及其均勻度對沖裁件的尺寸精度有決定性的影響。不同沖裁工藝、不同材料種類與不等料厚，間隙相差懸殊，沖壓精度差異很大。同一種模數(shù)m=0.34的2m

41、m的料厚、中心有孔的H62黃銅材料片齒輪復(fù)合模沖件，當(dāng)取間隙C=0.5%t（單邊），用復(fù)合精沖模沖制，沖件尺寸精度達(dá)到IT7級，沖件平直無拱彎，沖切面垂直度可達(dá)89.5°，其表面粗糙Ra值為0.2μm；而用普通復(fù)合模沖制，間隙C=5%t（單邊），沖件初始誤差亦即沖模的初始沖壓精度為1T9級，沖切面粗糙度Ra值為12.5μm，毛刺高度為0.10mm；還是這個(gè)沖件用連續(xù)模沖制，間隙C=7%t（單邊），初始沖件精度為IT11級，沖切

42、面更粗糙，甚至有肉眼可見的臺階。通常情況下，沖件材料及其厚度t是選取沖裁間隙的主要依據(jù)。一旦選定間隙就確定了沖件的平面尺寸的固定誤差的主體；沖件結(jié)構(gòu)剛度及立體形狀則影響其形位精度。</p><p>　　（2）沖壓工藝及沖模結(jié)構(gòu)類型</p><p>　　采用不同的沖壓工藝，沖件的精度及固定誤差相差甚大。除上述片齒輪實(shí)例說明，精沖工藝與普通沖裁的沖件精度與固定誤差相差一個(gè)數(shù)量級之外，即便在普通

43、沖裁中，采用不同間隙沖裁，固定誤差相差也很大。例如料厚t=1.5mm的H62黃銅沖裁件，選用C≤40%t單邊Ⅰ類小間隙沖裁比選用C≤8%t（單邊）Ⅲ類大間隙沖裁，沖件固定誤差將加大40%～60%，精度至少降一級。此外，采有無搭邊排樣，沖件的誤差要遠(yuǎn)大于有搭邊排樣沖件。無搭邊排樣沖件。無搭邊排樣沖件的精度低于IT12級，而多數(shù)有搭邊排樣的沖件精度在IT11～I(xiàn)T9級之間，料厚t＞4mm的沖件，尺寸精度會更低一些。</p>&

44、lt;p>　　不同沖模結(jié)構(gòu)類型，由于適用沖壓料厚及制造精度的差異，導(dǎo)致沖件的固定誤差有別。復(fù)合模中，多工位連續(xù)式復(fù)合模由于沖件連續(xù)重復(fù)定位加上制模誤差較大，故其沖件的固定誤差比單工位復(fù)合沖裁模要 </p><p><b>　　大1～2級。</b></p><p><b>　　（3）沖模制造工藝</b></p><p>

45、;　　沖模主要工作零件即凸、凹模的加工程序，對操作上的技術(shù)要求不高，能夠一次成形較復(fù)雜的模腔。但其加工表面約厚＞0.03～0.05mm為高溫?zé)g的殘余樹枝狀?yuàn)W氏體組織，硬度可高達(dá)HRC67～70，有顯微裂紋，容易在沖裁時(shí)出現(xiàn)崩刃或剝落。意大利Corrada公司的有關(guān)研究報(bào)告稱“線切割加工對表面金相結(jié)構(gòu)產(chǎn)生不利的影響，實(shí)際上已經(jīng)改變了金相結(jié)構(gòu)。我們必須用金剛石粉研磨或數(shù)控連續(xù)軌跡坐標(biāo)磨削（對線切割件）作精加工”。近年來瑞士和日本等國，對電

46、加工設(shè)備進(jìn)行了深入的研究和較大的改進(jìn)，制造出功能齊全的高精度NC和CNC線切割機(jī)，加工精度可達(dá)±0.005～0.001mm，甚至更小。加工表面粗糙度Ra值能達(dá)到0.4μm。根據(jù)近年對國內(nèi)12家生產(chǎn)線切割機(jī)工廠的調(diào)研，國產(chǎn)線切割機(jī)加工精度各別廠家的各別型號線切割機(jī)可達(dá)±0.008～±0.005mm，一般都在±0.01mm或更大一些，個(gè)別也能達(dá)到±0.005mm，加工表面粗糙度Ra值均大于1

47、.6μm。然而，電加工燒蝕金屬表面從而改變和損壞加工面金相結(jié)構(gòu)的特性不會改變，除非用磨削或其他加工法去除這一有害層。所以，僅僅用電加工法，包括電火花線切割與電穿孔，難以達(dá)到?jīng)_模</p><p>　　用精密磨削法制造沖模，特別是制造高精度、高壽命沖模，諸如：薄料小間隙復(fù)合沖裁模、多工位連續(xù)式復(fù)合模等，具有尺寸精度高、工作零件加工面粗糙度Ra值小、模具壽命高等特點(diǎn)。其加工工藝目前已由過去的普通機(jī)床粗加工改為電火花線切

48、割或電穿孔機(jī)粗加工，最后精密磨削，也由成型磨、光學(xué)曲線磨、手動(dòng)座標(biāo)磨逐步過濾到連續(xù)軌跡座標(biāo)磨及NC與CNC連續(xù)軌跡座標(biāo)磨，加工粗度可達(dá)±0.001～0.0005mm，加工表面粗糙度Ra值可達(dá)0.1～0.025μm。所以，用該工藝制造的沖模，無論尺寸精度、工作零件表面粗糙度，都能滿足沖模，尤其各種復(fù)合模的要求，比電加工工藝制造的沖模高一個(gè)檔次。</p><p>　?。?）間隙的大小與均勻度</p&g

49、t;<p>　　拉深、彎曲、翻邊及其他板料成形件一般都要先沖裁（落料）出平板展開毛坯，也有成形后落料、切開得到單個(gè)成品沖件。故沖裁作業(yè)，包括常用的沖孔、切口、切邊等，對于每種板料沖壓件都是必要的。所以沖裁間隙對沖件的外廓尺寸精度有決定性的影響。沖裁間隙小而均勻，可使沖裁尺寸獲取更高精度。對于拉深、彎曲等成形模，間隙大定將增大沖件口部尺寸誤差及回彈。間隙不均勻會使沖件毛刺加大并招致刃口的不均勻磨損。</p>&