外文翻譯--普通全鋼沖模的沖壓精度分析

1、<p>　　General all-steel punching die’s punching accuracy</p><p>　　Accuracy of panel punching part is display the press accuracy of the die exactly. But the accuracy of any punching parts’ linear dimensi

2、on and positional accuracy almost depend on the blanking and blanking accuracy,. So that the compound mould of compound punching’s accuracy, is typicalness and representation in the majority.</p><p>　　Analys

3、e of the die’s accuracy </p><p>　　For the analyse of pracyicable inaccuracy during production of dies to inactivation, we could get the tendency when it is augmentation in most time. From this we could analy

4、se the elements. When the new punch dies pt into production to the first cutter grinding, the inaccuracy produced called initial error; if the die grinding more than twenty times, until it’s discard, the inaccuracy calle

5、d conventional error; and before the dies discard, the largest error of the last batch permit, called limit</p><p>　　The initial error usually is the minimal through the whole life of die. Its magnitude depe

6、nd on the accuracy of manufacture, quality, measure of the punching part, thickness of panel, magnitude of gap and degree of homogeneity. The accuracy of manufacture depend on the manufacture process. For the 1 mm thicke

7、d compound punching part made in medium steel, the experimental result and productive practice all prove that the burr of dies which produced by spark cutting are higher 25%~~30% than produc</p><p>　　The nor

8、mal error of the punch die is the practicable error when the fist cutter grinding and the last cutter grinding before the die produce the last qualified product. As the increase of cutter grinding, caused the measure the

9、 nature wear of the dies are gradual increasing, the error of punching part increase also, so the parts are blew proof. And the die will be unused. The hole on the part and inner because the measure of wear will be small

10、 and small gradually, and its outside form will be la</p><p>　　The limit error in punching parts are the max dimension error which practicable allowed in the parts with limit error. This kind of parts usuall

11、y are the last qualified products before the die discard.</p><p>　　For the all classes of dies, if we analyse the fluctuate, tendency of increase and decrease and law which appeared in the die’s whole life,

12、we will find that the master of the error are changeless; the error that because the abrade of the cutter and impression will be as the cutter grinding times increased at the same time. And that will cause the error over

13、size gradually; and also have another part error are unconventional , unforeseen. Therefore, every die’ s error are composed of fixed error,</p><p>　　1. fixed error </p><p>　　At the whole proces

14、s when the New punching die between just input production to discard, the changeless master error that in qualified part are called fixed error. It’s magnitude is the deviation when the die production qualified products

15、before the first cutter grinding. Also is the initial error, but the die have initial punching accuracy at this time. Because of the abrade of parts, the die after grinding will be change the dimension error. And the inc

16、rement of deviation will oversize as the </p><p>　　(1) the material , sorts, structure, (form) dimension, and thick of panel</p><p>　　The magnitude of punching gap and degree of homogeneity are

17、have a important effect for the dimension accuracy. Different punching process, material, thick of panel, have completely different gap and punching accuracy. A gear H62 which made in yellow brass with the same mode numb

18、er m=0.34, 2mm thick and had a center hole, when the gap get C=0.5%t (single edge) , and punched with compound punching die, and the dimension accuracy reached IT7, the part have a flat surface ,the verticality of tangen

19、</p><p>　　(2) punching craft and molder structure type</p><p>　　Uses the different ramming craft, flushes a precision and the fixederror difference is really big. Except that the above piece gea

20、rexample showed, the essence flushes the craft and ordinary punching flushes a precision and the fixed error differs outside a magnitude,even if in ordinary punching center, uses the different gap punching, thefixed erro

21、r difference very is also big. For example material thickt=1.5mm H62 brass punching, selects C <= the 40%t unilateral I kind ofsmall gap punching comp</p><p>　　(3) the craft of punching die’s manufacture&

22、lt;/p><p>　　The main work of punching die namely are raised, the concave moldprocessing procedure, to operates on the specification not to behigh, can time form a more complex cavity. But its processing surface

23、approximately is thick > 0.03 ~ 0.05mm is the high temperatureablation remaining furcated austenite organization, degree ofhardness may reach as high as HRC67 ~ 70, has the micro crack, easilywhen punching appears bro

24、ke the cutter or flaking. The Italian CorradaCorporation''s related memoir called "th</p><p>　　With precisely rubs truncates the law manufacture punching die, specially makes the high accuracy,

25、the high life punching die, such as: Thin material small gap compound punching die, multi- locations continuous type compound die and so on, has the size precision high, the work component smachined surface roughness Ra

26、value is small, the mold life higher characteristic. Its processing craft at present changed the electrical fire by the past ordinary engine bed rough machining spark cutting or the</p><p>　　(4) gap size and

27、 degree of homogeneity </p><p>　　The flange and other sheet forming sgene rally all must first punching (fall material) the plate to launch the semi finished materials, after also has the forming to fall the

28、 material, the incision obtains the single end product to flush. Therefore punching the work, including is commonly used punching hole, the margin, cut side and so on, regarding each kind of sheet pressing partall is

29、 necessary. Therefore punching the gap to flushes a out form in chprecision to have the decisive influence</p><p>　　(5) ramming equipment elastic deformation In the ramming process </p><p>　　Aft

30、er the punch press load bearing can have the certain elastic deformation. Although this kind of distortion quantity according to flushes the pressure the size to change also to have the obvious directivity, but on the pr

31、essing part, mainly is to has the volume ramming archery target stamping, embosses, the equalization, the pressure is raised, the wave, flushes crowds, the shape, the flange, hits flatly, thinly changes draw ability and

32、so on the craft work punching forming flushes, has the si</p><p>　　普通全鋼沖模的沖壓精度分析</p><p>　　板料沖壓件的精度準確顯示出其沖模的沖壓精度。而任何沖件的線性尺寸精度與形位精度主要取決于沖模沖裁和立體成形沖壓件展開平毛坯的落料精度。因此，多工步復合沖壓的單工位復合模、多工位連續(xù)模的沖壓精度，在普通沖壓的眾

33、多種類與不同結構的沖模中，最具典型性和代表性。 沖模的沖壓精度分析</p><p>　　對沖模投產(chǎn)至失效報廢各個時期沖件的實際誤差分析，可以看出其增大的時期及趨向，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廢前沖制的沖件誤差稱之為常規(guī)誤差；而沖模失效報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

34、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），對于復合模尤為如此。所以，沖件毛刺高度的觸模檢查和測量并按企業(yè)標準或JB4129-85《沖壓件毛刺高度》對照檢測就顯得十分重要。 沖模的初始誤差通常是沖模整個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的中碳鋼復合沖裁模沖件，實驗結果與生產(chǎn)實踐都證明

35、，電火花線切割制造的沖模沖件毛刺高度比用成型磨或NC與CNC連續(xù)軌跡座標磨即精密磨削工藝制造的沖模沖件要高25%～30%。這是因為后者不僅加工精度高，而且加工面粗糙度Ra值要比前者小一個數(shù)量級，可達到0.025μm。因此，沖模的制造精度與質(zhì)</p><p><b>　　1、固定誤差</b></p><p>　　新沖模在指定的沖壓設備上投入使用至失效報廢的整個（總）壽命

36、過程中，其合格沖件誤差的主導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、結構（形狀）尺寸及料厚&l

37、t;/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2mm的料厚、中心有孔的H62黃銅材料片齒輪復合模沖件，當取間隙C=0.5%t（單邊），用復合精沖模沖制，沖件尺寸精度達到IT7級，沖件平直無拱彎，沖切面垂直度可達89.5°，其表面粗糙Ra值為0.2μm；而用普通復合模沖制，間隙C=5

38、%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；沖件結構剛度及立體形狀則影響其形位精度。（2）沖壓工藝及沖模結構類型 采用不同的沖壓工藝，沖