外文翻譯---沖模及復(fù)合模設(shè)計(jì)

1、<p><b>　　外文資料翻譯</b></p><p>　　Stamping and Punching Dies, Compound Die Design</p><p>　　A compound die performs only cutting operations (usually blanking and piercing) which are c

2、ompleted during a single press stroke. A characteristic of compound dies is the inverted position of the blanking die and blanking punch which also functions as the piercing die. The die is fastened to the upper shoe and

3、 the blanking punch having a tapered hole in it and in the lower shoe for slug disposal is mounted on the lower shoe.</p><p>　　The guide pins, or posts, are mounted in the lower shoes. The upper shoes contai

4、ns bushing which slide on the guide pins. The assembly of the lower and upper shoes with guide pins and bushing is a die set. Die sets in many sizes and designs are commercially available.</p><p>　　On the up

5、stroke of the press slide, the knock out rod of the press strikes the ejector plate, forcing the ejector tie rod and shedder downward, thus pushing the finished work piece out of the blanking die. Four special shoulder s

6、crews (stripper bolts), commercially available, guide the stripper in its travel and retain it against the preload of its springs. The blanking die as well as the punch pad is screwed and doweled to the upper shoe.</p

7、><p>　　Bending Die </p><p>　　Bending is the uniform straining of material, usually flat sheet or strip metal, around a straight axis which lies in the neutral plane and normal to the lengthwise dir

8、ection of the sheet or strip. Metal flow takes place within the plastic range of the lengthwise direction of the bend retains a permanent set after removal of the applied stress. The inner surface of a bend is in compres

9、sion; the outer surface is in tension. A pure bending action does not reproduce the exact shape of the punch and</p><p>　　Bending Methods</p><p>　　Metal sheet or strip, supported by a V bending,

10、 produces a bend having an included angle which may be acute, obtuse, or of 90. Friction between a spring-loaded knurled pin in the Vee of a die and the part will prevent or reduce side creep of the part during its bendi

11、ng. Other methods are Z-bending edge bending and U-bending etc.</p><p>　　Drawing Die</p><p>　　Drawing is a process of changing a flat, precut metal blank into a hollow vessel without excessive w

12、rinkling, thinning, or fracturing. The various forms produced may be cylindrical or box-shaped with straight or tapered sides or sides or a combination of straight, tapered, or curved sides. The size of the parts may var

13、y from 0.25mm diameter or smaller, to aircraft or automotive parts large enough to require the use of mechanical handing equipment.</p><p>　　Single-action Die</p><p>　　The simplest type of draw

14、dies is one with only a punch and die. One type of drawing die use in a single-action press is shown in Fig.3-4. This die is plain single-action type where the punch pushes the metal blank into the die, using a spring-lo

15、aded pressure pad to control the metal flow. The punch has an air vent to eliminate suction which would hold the cup on the punch and damage the cup when it is stripped from the punch by the pressure pad. The sketch show

16、s the pressure pad fitting the sto</p><p>　　Mold Cavities and Cores</p><p>　　The cavity and core give the molding its external shapes respectively, the impression imparting the whole of the form

17、 to the molding. When then proceeded to indicate alternative ways by which the cavity and core could be incorporated into the mold and we found that these alternatives fell under two main headings, namely the integer met

18、hod and the insert method. Another method by which the cavity can be incorporated is by means of split inserts or splits.</p><p>　　When the cavity or core is machined from a large plate or block of steel, or

19、 is cast in one piece, and used without bolstering as one of the mold plates, it is termed an integer cavity plate or integer core plate. This design is preferred for single-impression molds because of characteristics of

20、 the strength, smaller size and lower cost. It is not used as much for multi-impression molds as there are other factors such as alignment which must be taken into consideration.</p><p>　　Of the many manufac

21、turing processes available for preparing molds only two are normally used in this case. There are a direct machining operation on a rough steel forging or blank using the conventional machine tool, or the precision inves

22、tment casting technique in which a master pattern is made of the cavity and core. The pattern is then used to prepare a casting of the cavity or core by or special process.</p><p>　　A 4.25% nickel-chrome-mol

23、ybdenum steel (BS 970-835 M30) is normally specified for integer mold plates which are to be made by the direct machining method.</p><p>　　The precision investment casting method usually utilizes a high-chro

24、me steel.</p><p>　　For molds containing intricate impressions, and for multi-impression molds, it is not satisfactory to attempt to machine the cavity and core plates from single blocks of steel as with inte

25、ger molds. The machining sequences and operation would be altogether too complicated and costly. The inset-bolster assembly method is therefore used instead.</p><p>　　The method consists in machining the imp

26、ression out of small blocks of steel. These small blocks of steel are known, after machining, as inserts, and the one which forms the male part is termed the core insert and, conversely, the one which forms the female pa

27、rt the cavity inserts. These are then inserted and securely fitted into holes in a substantial block or plate of steel called a bolster. These holes are either sunk part way or are machined right through the bolster plat

28、e. In the latter cas</p><p>　　Both the integer and the insert-bolster methods have their advantages depending upon the size, the shape of the molding, the complexity of the mold, whether the single impressio

29、n or a multi-impression mold is desire, the cost of making the mold, etc. It can therefore be said that in general, once the characteristics of the mold required to do a particular job which have been weighed up, the dec

30、ision as to which design to adopt can be made.</p><p>　　Some of these considerations have already been discussed under various broad headings, such as cost, but to enable the reader to weigh them up more eas

31、ily, when faced with a particular problem, the comparison of the relative advantages of each system is discussed under a number of headings.</p><p>　　Unquestionably, for single impression molds integer desig

32、n is to be preferred irrespective of whether the component form is a simple or a complex one. The resulting mold will be stronger, smaller, less costly, and generally incorporate a less elaborate cooling system than the

33、insert-bolster design. It should be borne in mind that local inserts can be judiciously used to simplify the general manufacture of the mold impression.</p><p>　　For multi-impression molds the choice is not

34、so clear-cut. In the majority of cases the insert-bolster method of construction is used, the ease of manufacture, mold alignment, and resulting lower mold costs being he overriding factors affecting the choice. For comp

35、onents of very simple form it is often advantageous to use one design for one of the mold plate and the alternative design for the other. For example, consider a multi-impression mold for a box-type component. The cavity

36、 plate could be</p><p><b>　　沖模及復(fù)合模設(shè)計(jì)</b></p><p>　　復(fù)合模是指在一次沖壓行程中完成幾道沖裁工序（通常包括落料和沖孔）的模具。復(fù)合模的特點(diǎn)是能夠調(diào)轉(zhuǎn)落料模和沖孔模（凸模和凹模）的位置，即落料模也可以作為沖孔模。沖頭和內(nèi)部帶有錐孔的落料凹模被固定在上模座板上，下模座板上開(kāi)有推桿放置孔。</p><p

37、>　　導(dǎo)料銷(xiāo)或?qū)е惭b在下模座上，導(dǎo)套安裝在上模座上且可以沿導(dǎo)柱滑動(dòng)。上、下模座（帶有導(dǎo)柱和導(dǎo)套）組合成模架。模架在市場(chǎng)上可以買(mǎi)到，且有多種尺寸和結(jié)構(gòu)供選擇。</p><p>　　在沖壓機(jī)滑塊的向上行程中，沖壓機(jī)的打料桿接觸到推件板，作用在連接推桿上的力使卸料裝置下移，將沖壓件從落料凹模中推出。四個(gè)特殊的帶肩螺釘（卸料螺釘，在市場(chǎng)上可以買(mǎi)到）引導(dǎo)卸料裝置移動(dòng)，并使其抵抗彈簧的預(yù)壓。與沖孔凹模一樣，落料凹模也

38、用螺栓和銷(xiāo)釘安裝在上模座上。</p><p><b>　　彎曲模</b></p><p>　　彎曲是指材料（通常是板料或條料）圍繞位于中性面上縱向的直線軸產(chǎn)生均勻變形的沖壓工藝。因?yàn)閺澢鷷r(shí)金屬流動(dòng)發(fā)生在金屬塑性變形范圍內(nèi)，所以去除施加的外力后，彎曲將保持永久的變形。彎曲件的內(nèi)表面處于壓縮狀態(tài)，外表面處于拉伸狀態(tài)。單一的彎曲工序并不能使金屬材料呈現(xiàn)出與模具的凹?；蛲鼓Ｍ?/p>

39、全一致的狀態(tài)，這種復(fù)制工藝也是一種成型方法。在受到彎曲作用的金屬中，中性面是彎曲金屬上張力為零的平面區(qū)域。</p><p><b>　　彎曲方式</b></p><p>　　放置在V 形支撐塊中的板料或條料在楔形沖頭的作用下壓入V形凹模，這類(lèi)彎曲方式稱(chēng)為V形彎曲。V形彎曲能夠生產(chǎn)帶有鈍角、銳角或直角的彎曲件。V形模具內(nèi)的彈簧加載壓銷(xiāo)和零件之間的摩擦力將組織或減少?gòu)澢鷷r(shí)

40、邊緣的移動(dòng)。其他彎曲方式有Z形彎曲、側(cè)邊彎曲和U形彎曲等。</p><p><b>　　拉深模</b></p><p>　　拉深是把一定形狀的金屬平板制成空心零件而不發(fā)生起皺、變薄或開(kāi)裂現(xiàn)象的沖壓工序。不同形狀的拉深可得到不同圓柱形或盒形制件，這些側(cè)壁的形式有直壁、錐形壁、直壁和錐形壁混合的側(cè)壁以及曲面壁。拉深件的尺寸相差很大，從直徑為0.25mm或更小的拉深件，到足

41、以覆蓋機(jī)械設(shè)備的航天器或汽車(chē)覆蓋件。</p><p><b>　　單次拉深模</b></p><p>　　最簡(jiǎn)單的拉深模指帶有一對(duì)凹模和凸模，這種結(jié)構(gòu)是簡(jiǎn)單的單動(dòng)沖壓類(lèi)型，沖頭把金屬胚料壓入凹模，利用彈壓板控制金屬流動(dòng)。沖頭上開(kāi)設(shè)的排氣孔能夠消除推出拉深件時(shí)產(chǎn)生的真空吸力，這種真空現(xiàn)象能使杯形拉深件包緊在沖頭上，若有壓料板強(qiáng)制脫模，則會(huì)損壞杯形件。模具裝有壓料板，壓料

42、板起壓料作用沖壓時(shí)能為沖頭外的胚料提供均勻而合適的壓力。如果彈簧板沒(méi)有安全墊圈，那么彈簧壓縮量越多，板料承受的壓力就越大，這將限制拉深的程度。由于有效的壓力有限，故這種拉深模使用于所需沖壓力較小及深度較淺的沖壓件。</p><p><b>　　型腔和型芯</b></p><p>　　模具的型腔和型芯分別形成塑件內(nèi)部和外部形狀，型腔形狀決定了塑件外部形狀，接下來(lái)我們簡(jiǎn)要

43、說(shuō)明選擇哪種方式把型腔和型芯安裝在模具中，這些方式可歸納為兩大類(lèi)，即整體式和鑲拼式。另一種組成型腔的方式是加入拼塊或滑塊。</p><p>　　當(dāng)型腔或型芯由一塊大的鋼板或剛塊加工而成，或者鑄成一體，不需使用支承板件而形成一塊模板時(shí)，就構(gòu)成整體式型腔板或型芯板。這種設(shè)計(jì)因具有強(qiáng)度高、尺寸小和成本低的特性，而主要應(yīng)用在單型腔模具中。整體式型腔和型芯一般不用在多用于多型腔模具中，因?yàn)槎嘈颓荒＞咴O(shè)計(jì)時(shí)必須考慮一些其他因

44、素，例如安裝組合鑲件等。</p><p>　　在模具制造的眾多方法中，用于加工整體式型腔板或型芯板的方法主要有兩種：使用傳統(tǒng)機(jī)床對(duì)粗鍛鋼胚料直接加工，或利用精確的熔模鑄造技術(shù)將胚料加工成型腔和型芯。用于制造型腔和型芯的胚料經(jīng)常需要特殊工藝的處理。</p><p>　　通常，4.25%的鎳鉻鉬合金鋼（BS970-835M30）是生產(chǎn)整體模板的制定材料，選用這種材料時(shí)采用直接的機(jī)加工方式。&l

45、t;/p><p>　　精確的熔模鑄造常常用來(lái)加工高鉻鋼。</p><p>　　對(duì)于成型部模具和位復(fù)雜的多腔模，也像整體式模具那樣用一塊鋼材加工型腔和型芯并不容易。如果采用整體式結(jié)構(gòu)，則加工順序和操作過(guò)程將變得非常復(fù)雜，成本也高，因此鑲拼式裝配方式替代了整體式。</p><p>　　鑲拼式型腔由小鋼塊加工而成。加工后的小鋼塊作為鑲件，形成型芯部分的稱(chēng)為型芯嵌塊，相反的，形

46、成型腔部分的稱(chēng)為型腔嵌件。然后，把這些嵌件牢固的安裝在被稱(chēng)為墊板的孔中，墊板有實(shí)心鋼板或鋼塊加工而成。這些安裝孔有的是由墊塊的局部凹陷形成，有的是在墊板上直接加工而成的。在后一種方式中，墊板后部還要加一塊模板，起加固作用，確保鑲件安裝到位。</p><p>　　整體式和鑲拼式結(jié)構(gòu)均有優(yōu)點(diǎn)，這取決于塑件尺寸和形狀、模具的復(fù)雜程度、所需的是單型腔模具還是多型腔模具以及模具的制造成本等。通常，塑件的形狀、尺寸等特性確定

47、后，采用哪種形式的型腔和型芯就已經(jīng)確定了。</p><p>　　在不同的章節(jié)中，我已經(jīng)討論過(guò)型腔和型芯的安裝方式所涉及的問(wèn)題，例如成本等。但為使讀者在處理特殊問(wèn)題時(shí)更容易知道重點(diǎn)所在，我們將用一定的章節(jié)再次討論每種結(jié)構(gòu)優(yōu)缺點(diǎn)的對(duì)比。</p><p>　　毫無(wú)疑問(wèn)，對(duì)于單型腔模具，無(wú)論是簡(jiǎn)單還是復(fù)雜，整體式型腔是首選方式。若選擇整體式，則模具的強(qiáng)度高、體積小、成本低，而冷卻系統(tǒng)的設(shè)計(jì)卻比鑲拼

48、式簡(jiǎn)單、方便。設(shè)計(jì)時(shí)需要常記于心的是，適當(dāng)?shù)氖褂描偧梢院?jiǎn)單化模具型腔的加工制造難度。</p><p>　　對(duì)于多型腔模具選擇哪種方式不是很明顯。大多數(shù)多型腔模具采用鑲拼式結(jié)構(gòu)，這種結(jié)構(gòu)加工簡(jiǎn)單、裝配容易、模具成本低，這些是影響選擇哪種結(jié)構(gòu)形式的最重要因素。一種非常簡(jiǎn)單且具有很多優(yōu)點(diǎn)的設(shè)計(jì)形式是采用一種形式設(shè)計(jì)模板，而采用另一種形式設(shè)計(jì)模具的其他部分。例如，采用箱型組件設(shè)計(jì)多型腔模具。型腔板設(shè)計(jì)成小型整體式模板，