机械磨具外文翻译

1、外文文献资料General all-steel punching die s punching accuracy General all- steel punching die s punching accuracy Accuracy of panel 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

2、 and blanking accuracy,. So that the compound mould of compound pun ching asccuracy, is typicalness and representation in the majority.Analyse of the die s accuracyFor the analyse of pracyicable inaccuracy during production of dies to inactivation, we could get the tendency when it is augmentation i

3、n most time. From this we could analyse the elements. When the new punch dies pt into production to the first cutter grinding, the inaccuracy produced called initial error; i f the die grinding more than twenty times, until it s discard, the inaccuracy called conventional error; and before the dies

4、discard, the largest error of the last batch permit, called limiting error. at job site, the evidence to confirm life of sharpening is the higher of the blanking, punched hole or punched parts. Because all finished parts had been blanked ,so it is especially for the compound dies. Therefore, the ana

5、lyse of burr and measurement is especially important when do them as enterprise standardization or checked with .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, mag

6、nitude 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 prove that the burr of dies which produced by spark cutting are higher 25%30%

7、than produced by grinder ,NC or CNC. The reason is that not only the latter have more exact machining accuracy but also the value of roughness Ra is less one order than the formmer, it can be reached 0.025卩 m. Therefore, the die s initial blanked accuracy depends on theaccuracy of manufacture, quali

8、ty and so on.The normal 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 nature wear of the dies are gradual increasing, the error o

9、f 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 and small gradually, and its outside form will be lager in the same reason. Therefore, the hole and inner form in the part will be made mou

10、ld according to one-way positive deviation or nearly equal to the limit max measure. In like manner, the punching part s appearance will be made mould according to-ownaey negative deviation or nearly equal to limit mini measure. For this will be broaden the normal error, and the cutter grinding time

11、s will be increased, the life will be long.The limit error in punching 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.For the all classes of dies, if we analyse the fluctuate

12、, 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; theerror 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 o

13、versize gradually; and also have another part error are unconventional , unforeseen. Therefore, every die s error are composed of fixed error, system error, accident error and so on.1. fixed error At the whole process when the New punching die between just input production to discard, the changeless

14、 master error that in qualified part are called fixed error. Its magnitude is the dwhen the die production qualified products 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 w

15、ill be change the dimension error. And the increment of deviation will oversize as the times of cutter grinding. So the punching accuracy after cutter grinding also called “ grinding accuracy ”and lower tan initial accuracy. The fixed error depend on the elements factor as followed :(1) the material

16、 , sorts, structure, (form) dimension, and thick of panel the magnitude of punching gap and degree of homogeneity are 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 i

17、n 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 with compound punching die, and the dimension accuracy reached IT7, the part have a flat surface ,the verticality of tangent plane reached 89.5, its roughness Ra mag

18、nitude are 12.5height of burr are 0.10mm; and the punching part are punched with progressive die, the gap C=7%t (single edge) , initial accuracy are IT11, and have an more rough surface, even can see the gap with eyes. In the usual situation, flushes a material and its thickness t is theselection pu

19、nching gap main basis. Once the designation gap haddetermined flushes the plane size the fixed error main body; Flushesthe structure rigidity and the three-dimensional shape affects itsshape position precision.(2) punching craft and molder structure type Uses the different ramming craft, flushes a p

20、recision 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 fixed error differs outside amagnitude,even if in ordinarypunching center, uses the different gap punching, thefixed e

21、rror difference veryis also big. Forexample material thickt=1.5mm H62 brass punching, selects C = the 40%t unilateral I kind ofsmall gap punching compared to select C 4mm flushes, the size precision can lower some. Different dies structure type, because is suitable the rammingmaterial to be thick an

22、d themanufacture precision difference, causesto flush a fixed error to have leaves. Compound die center, multi-locations continuous type compound die because flushes continuously toduplicate the localization to add on the pattern making error to bebigger, therefore it flushes a fixed error compound

23、punching die to wantcompared to the single location Big 1 2 levels(3) the craft of punching die s manufacture the main work of punching die namely are raised, the concave moldprocessing procedure, tooperates on the specification not to behigh, can time form a more complex cavity. But its processing

24、surfaceapproximately 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 broke the cutter or flaking. The Italian CorradaCorporations related memoir called th

25、e line cut the processing contruction to have the disadvantageous influence to the superficialgold, in fact already changed the gold contruction. We must use theJingang stone powder to grind or the numerical control continual pathcoordinates rub truncate (cut to line) to make the precision work . In

26、 recent years country and so on Switzerland and Japan, has conductedthe thorough research to the electrical finishing equipment and abigger improvement, makes function complete high accuracy NC and theCNC line cutter, the processing precision may reach 0.005 0.001mm,even is smaller. The processing s

27、urface roughness Ra value can achieve0.4 mu m. According to the recent years to the domestic 12 productionlines cutter factory investigation and study, the domesticallyproduced line cutter processing precision different factory differentmodel line cutter might reach 0.008 0.005mm, generally all in 0

28、.01mm or bigger somewhat, was individual also can achieve 0.005mm, the processing surface roughness Ra value was bigger than1.6 卩 rHowever, the electrical finishing ablation metal surface thus the change and the damage machined surface mental structure character can not change, only if with rubs tru

29、ncates or other ways reroves this harrful level. Therefore, rerelyuses electricity rachining, including the spark cutting and the electricity perforation, achieves with difficulty punching, especially high accuracy, high life punching die to size precision and work corponents surface roughness Ra va

30、lue request.With precisely rubs truncates the law ranufacture punching die, specially rakes the high accuracy, the high life punching die, such as: Thin raterial srall gap corpound punching die, rulti- locations continuous type corpound die and so on, has the size precision high, the work corponent

31、srachined surface roughness Ra value is srall, the rold life higher characteristic. Its processing craft at present changed the electrical fire by the past ordinary engine bed rough rachining spark cutting or the electricity puncher rough rachining, finally precisely rubs truncates, also fror takes

32、shape rubs, optics curve rubs, the ranual grid reference rubs gradually filters the continual path grid reference to rub and NC and the CNC continual path grid reference rubs, Processing coarseness ray reach 0.001 0.0005rr, the processing surface roughness Ra value ray reach 0.1 0.025 ru r. Therefor

33、e, with this craft ranufacture the die , regardless of the size precision, the work corponents surface roughness, all can satisfy die, each kind of corpound request, the die is especially higher than the electrical finishing craft ranufacture scale.(4) gap size and degree of horogeneitythe flange an

34、d other sheet forring sgene rally all rust first punching (fall raterial) the plate to launch the seri finished raterials, after also has the forring to fall the raterial, the incision obtains the single end product to flush. Therefore punching the work, including is corronly used punching hole, the

35、 rargin, cut side and so on, regarding each kind of sheet pressing partall is necessary. Therefore punching the gap to flushes a out forr in chprecision to have the decisive influence. punching the gap srall and is even, ray cause punching the size gain high accuracy. Regarding drawability, is curvi

36、ng and so on rould, the gap greatly will decide increases flushes the oral area size error and the snapping back. The gapnon-uniforrity can cause to flush a burr enlarges and incurs cutting edge the non-uniforr attrition.（5）ramming equipment elastic deformation In the ramming processAfter the punch

37、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 pressing part, mainly is to has the volume ramming archery target stamping, embosses, the equal

38、ization, 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 significant influence to its ramming aspect size precision 外文译文 普通全钢冲模的冲压精度分析 冲压零件的精度是面板显示媒体模具的精度完全正确。但其准确性的冲压零件的尺寸和位置

39、精度线性几乎 取决于冲裁下料精度。所以复合模具的复合冲压的准确性在普通冲压的众多种类与不同结构的冲模中，最 具典型性和代表性。冲模的冲压精度分析 对冲模投产至失效报废各个时期冲件的实际误差分析，可以看出其增大的时期及趋向，从而分析其增大的 因素。新冲模投产至第一次刃磨前冲制冲件的误差即所谓的初始误差； 冲模经过 20 次左右刃磨至失效报废 前冲制的冲件误差称之为常规误差；而冲模失效报废前冲制的最后一批合格冲件的允许最大误差称之为极 限误差。在现场，确定冲模刃磨寿命的依据是冲件冲孔与落料的毛刺高度。由于任何成形件都具有冲裁作 业（毛坯落料或冲孔） ，对于复合模尤为如此。所以，冲件毛刺高度的触模检

40、查和测量并按企业标准或 JB4129-85冲压件毛刺高度对照检测就显得十分重要。冲模的初始误差通常是冲模整个寿命中冲件误差最小的。其大小主要取决于冲模的制造精度与质量及冲件尺寸、料厚以及间隙值大小与均匀度。冲模的制造精度及质量又取决于制模工艺。对于料厚t 1mm的中碳钢复合冲裁模冲件，实验结果与生产实践都证明，电火花线切割制造的冲模冲件毛刺高度比用成型磨或NC与CNC连续轨迹座标磨即精密磨削工艺制造的冲模冲件要高25%30%。这是因为后者不仅加工精度高，而且加工面粗糙度 Ra值要比前者小一个数量级，可达到 0.025卩m。因此，冲模的制造精度与质量等 因素决定了冲模的初始冲压精度，也造就了冲件

41、的初始误差。 冲件的常规误差是冲模经第一次刃磨到最后一次刃磨后冲出最后一个合格冲件为止，冲件实际具有的误差。随着刃磨次数的增加，刃口的自然磨损而造成的尺寸增量逐渐加大，冲件的误差也随之加大。当其误差超 过极限偏差时，冲件就不合格，冲模也就失效报废。 / 冲件上孔与内形因凸模磨损尺寸会逐渐变小；其 外形落料尺寸会因凹模磨损而逐渐增大。所以，冲件上孔与内形按单向正偏差标允差并依接近或几乎等于 极限最大尺寸制模。同理，冲件外形落料按单向负偏差标注允差并依接近或几乎等于极限最小尺寸制模。 这样就使冲件的常规误差范围扩大，冲模可刃磨次数增加，模具寿命提高。冲件的极限误差是具有极限偏差的冲件所具有的实际允

42、许的最大尺寸误差。这类冲件通常是在冲模失效报 废前冲制的最后一批合格冲件。对各类冲模冲件误差在冲模整个寿命中出现的波动、增减趋向及规律等进行全面分析便可发现：冲件误差 的主导部分是不变的；因刃口或型腔的自然磨损而出现的误差增量随冲模刃磨冲数增加而使这部分误差逐 渐加大；还有部分误差的增量是非常规的、不可预见的。所以，各类冲模冲件误差是由因定误差、渐增误 差、系统误差及偶发误差等几部分综合构成。1 、固定误差 新冲模在指定的冲压设备上投入使用至失效报废的整个（总）寿命过程中，其合格冲件误差的主导部分固 定不变即所谓固定误差。其大小就是新冲模第一次刃磨前冲制的合格冲件的偏差，也即冲模的初始误差，

43、而此时的冲模具有初始冲压精度。刃磨后的冲模，因其工作零件（凸、凹模）磨损而改变尺寸误差，使冲 件识差增量随刃磨次数增加而逐渐加大，故冲模刃磨后的冲压精度亦称“刃磨精度”比其初始精度要低。 冲模冲件的固定误差取决于以下各要素：（1）冲件的材料种类、结构（形状）尺寸及料厚 冲裁间隙的大小及其均匀度对冲裁件的尺寸精度有决定性的影响。不同冲裁工艺、不同材料种类与不等料 厚，间隙相差悬殊，冲压精度差异很大。同一种模数 m=0.34 的 2mm 的料厚、中心有孔的 H62 黄铜材料片 齿轮复合模冲件，当取间隙 C=0.5%t （单边），用复合精冲模冲制，冲件尺寸精度达到IT7 级，冲件平直无拱弯，冲切面垂直度可达89.5 ,其表面粗糙Ra值为0.2卩m；而用普通复合模冲制， 间隙C=5%t （单边）， 冲件初始误差亦即冲模的初始冲压精度为1T9级，冲切面粗糙度 Ra值为12.5卩m,毛刺高度为0.10mm;还是这个冲件用连续模冲制，间隙 C=7%t （单边） ，初始冲件精度为 IT11 级，冲切面更粗糙，甚至有肉眼 可见的台阶。通常情况下，冲件材料及其厚度 t 是选取冲裁间隙的主要依据。一旦选定间隙就确定了冲件 的平面尺寸的固定误差的主体；冲件结构刚度及立体形状则影响其形位精度。（ 2）