材料成型及控制工程專業(yè)畢業(yè)設(shè)計(jì)（論文）外文翻譯

1、<p><b>　　中文2500字</b></p><p><b>　　本科畢業(yè)設(shè)計(jì) 翻譯</b></p><p>　　學(xué)生姓名：*****</p><p>　　班 級(jí)：*****班</p><p>　　學(xué) 號(hào)：*****</p><p>　　學(xué)

2、院：材料科學(xué)與工程學(xué)院</p><p>　　專 業(yè)：材料成型及控制工程</p><p>　　指導(dǎo)教師：***** 副教授</p><p>　　2011年3月25日</p><p>　　Section 4 – Die Design and Construction Guidelines for HSS Dies</p>&l

3、t;p>　　General Guidelines for Die Design and Construction</p><p><b>　　Draw Dies</b></p><p>　　Higher than normal binder pressure and press tonnage is necessary with H.S.S. in order

4、to maintain process control and to minimize buckles on the binder. Dies must be designed for proper press type and size. In some cases, a double action press or hydraulic press cushion may be required toachieve the neces

5、sary binder forces and control. Air cushions or nitrogen cylinders may not provide the required force for setting of draw beads or maintaining binder closure if H.S.S. is of higher strength or </p><p>　　Draw

6、 beads for H.S.S. should not extend around corners of the draw die. This will result in locking out the metal flow and cause splitting in corners of stamping. Draw beads should “run out” at the tangent of the corner radi

7、us to minimize metal compression in corners, as shown in figure 16 on page 47.</p><p>　　Better grades of die material may be necessary depending on the characteristics of the HSS, the severity of the part ge

8、ometry, and the production volume. A draw die surface treatment, such as chrome plating, may be recommended for outer panel applications.</p><p>　　Form and Flange Dies</p><p>　　Part setup in for

9、m and flange dies must allow for proper overbend on all flanges for springback compensation. Springback allowance must be increased as material strength increases; 3 degrees for mild steels, but 6 degrees or more for HSS

10、.</p><p>　　Punch radii must be fairly sharp. 1t for lower strength steels. Higher strength steels may require larger radii, but keeping them as small as practical will reduce springback in the sidewalls.<

11、/p><p>　　Flange steel die clearance must be held to no more than one metal thickness clearance to reduce springback and sidewall curl.</p><p>　　Form and flange steels should be keyed or pocketed in

12、 the casting to avoid flexing.</p><p>　　Flange steels should be designed to wrap over and coin the flange break in order to set the break and reduce springback. See figure 17 on page 48. </p><p>

13、;　　Die strength must not be compromised with light-weight die construction. High strength steel will require a stiffer die to resist flexing and the resultant part distortions, especially for channel or “hat-section” par

14、ts. This type of part can also cause serious die damage if double blanks occur.</p><p>　　Cutting Dies</p><p>　　To reduce press tonnage requirements and extend die life, a minimum shear of four t

15、o six times metal thickness in twelve inches of trim steel length is recommended.</p><p>　　To reduce die maintenance, maximum trim angles should be about 5° to 10° less than those used for mild ste

16、el. Trim steels should be keyed or pocketed in casting to avoid flexing. Die clearance should be 7 to 10% of metal thickness.</p><p>　　Drawbead Types</p><p>　　Conventional Drawbeads

17、 Run-out Drawbeads For H.S.S.</p><p>　　Lock Beads for Stretch-Form Die</p><p><b>　　Figure 16</b></p><p>　　1. Providing a vertical step in the flange stiffens and straigh

18、tens the flange, stopping sidewall curl as well as springback.</p><p>　　2. The addition of stiffening darts helps maintain a 90-degree flange.</p><p>　　3. By adding a horizontal step along the f

19、lange, the flange is stiffened, resulting in reduced springback.</p><p>　　4. Back relief on the upper flange steel allows for extra pressure to be applied futher out on the formed radius.</p><p>

20、;　　Section 5 – Die Tryout Guidelines for High Strength Steel Dies</p><p>　　General Guidelines for Die Tryout</p><p><b>　　Draw Dies</b></p><p>　　Higher draw die binder pr

21、essure and press tonnage will be necessary in order to maintain process control and draw parts without buckles. A double action press or a press with hydraulic cushion may be required in some cases to achieve the require

22、d binder forces.</p><p>　　HSS draw die operations will require sheet steel lubricants that are formulated for extreme pressures. Mill oils will not provide sufficient lubricity for most applications. Pre-lub

23、es or dry film lubricants may be necessary for process control.</p><p>　　Die plan view punchline corner radii should be larger than with mild steels to avoid buckling in the corners of the binder.</p>

24、<p>　　Stretch Form Dies</p><p>　　Lock beads may require modification to avoid cracking or tearing with higher strength grades of HSS. Opening side walls of beads and enlarging corner radii will avoid c

25、racking of high strength sheet steel. Lock beads should be continuous around the punchline for stretch form dies.</p><p>　　For large panels from stretch-form dies, such as a roof panel or hood outer, elastic

26、 recovery may result in a shrunken panel that does not fit well on the male die member of the trim or flange dies. This problem is corrected by adding a “plus” factor to the overall part dimensions of the draw die or str

27、etch form die punch. This “plus” is usually no more than 2.5 mm at the center of the sides and the front, tapering to 0.0mm at the corners of the part profile on the punch. Finish part profile is </p><p>　　F

28、orm and Flange Dies</p><p>　　The punch radius should be fairly sharp with 1 or 2t used for lower strength steel. HSS may require larger radii, but as small as practical to reduce springback of sidewalls.<

29、/p><p>　　The flange steel radius affects sidewall curl and springback on any offset flanges. This radius should also be small to reduce springback of side flanges.</p><p>　　Overbend for springback

30、compensation must be increased as tensile strength increases: 3 degrees is standard for mild steels, but 6 degrees or more will be required for HSS.</p><p>　　Flange steel die clearance should be tight, maint

31、aining no more than one metal thickness clearance to reduce springback and sidewall curl.</p><p>　　Cutting Dies</p><p>　　To reduce press tonnage requirements and extend die life, a minimum shear

32、 of four to six times metal thickness in twelve inches of trim steel length is required.</p><p>　　Die clearance should be 7 to 10% of metal thickness for HSS.</p><p>　　To reduce trim steel maint

33、enance, reduce maximum trim angles by about 5° to 10° from those used for mild steel. Trim steels should be keyed or pocketed in the casting to avoid flexing.</p><p>　　Die Tryout When Using Bake Ha

34、rdenable Steel</p><p>　　In order to obtain the maximum benefits of BHS, tryout of the dies should be performed as follows: Circle grid analysis must be performed on a panel before any die rework is attempted

35、. With the gridded panel as a reference, the die can be modified to provide a minimum biaxial stretch of 2.0%. Stretch-form or draw dies are best for this material.</p><p>　　For rough or functional tryout, i

36、t is possible to use mild steel with a 6% to 8% gauge increase to perform the normal process of die preparation. This alleviates complications when the BHS strengthens between each die being tried out. The reason for thi

37、s is the time lag that normally occurs between a panel being formed and its use in the next operation.</p><p>　　When the entire line of dies is ready for approval, all dies must be set in line. Panels should

38、 be run through all the die operations consecutively. This will avoid some of the strengthening effects of time delays between stamping operations that can cause variation in panels. Dimensional approval of the panel wil

39、l be most difficult if this procedure is not followed.</p><p>　　The strengthening reaction in the BHS can cause dimensional variation in flanges since springback will vary with time as the strength increases

40、. This is why running the panel through all die operations consecutively is crucial to a successful buyoff.</p><p>　　Part Buyoff</p><p>　　To reduce the part buyoff time and eliminate many hours

41、of tryout time, the benefits of functional build must be considered. This procedure has been proven to save time and money by concentrating on an acceptable sub-assembly rather than making each stamping to part specifica

42、tions. Those parts that are easiest to change are revised to suit the sub-assembly dimensional targets. Those parts that do not affect the sub-assembly quality are not changed, but the detail part specifications are revi

43、sed.</p><p>　　In addition to saving tryout time and die rework costs with functional build, lower part variation can also be realized. Two dimensional challenges faced by the die maker when first trying out

44、dies are to reduce the dimensional variation from nominal specifications, and to reduce the short term variation</p><p>　　from part to part. The typical priority is to first minimize part-to-part variation a

45、nd later address nominal deviation. A strong argument for this strategy is that the deviation from nominal is not precisely known until a dimensionally consistent part can be evaluated. The results are a dimensionally co

46、nsistent part even though a number of checkpoints may deviate from nominal, and perhaps even be out of tolerance. In many situations when dimensions on the die are reworked to shift them closer t</p><p>　　Fo

47、r more information on functional build, refer to the Auto/Steel Partnership publication. “Event-Based Functional Build: An Integrated Approach to Body Development”.</p><p>　　第四節(jié)-高強(qiáng)度鋼模具設(shè)計(jì)和制造指南</p><

48、p>　　對(duì)模具設(shè)計(jì)和制造的一般準(zhǔn)則</p><p><b>　　拉深模具</b></p><p>　　為了控制高強(qiáng)度鋼的成形并減少板料邊緣的彎曲，高強(qiáng)度鋼成型時(shí)的壓力和噸位高于一般情況是必要的。模具設(shè)計(jì)必須考慮適當(dāng)?shù)膲毫︻愋秃统叽?。在某些情況下，為了達(dá)到需要的壓邊力和控制力可以用一種雙動(dòng)壓力墊或液壓墊。如果高強(qiáng)度鋼有更高的強(qiáng)度和厚度，空氣墊子或氮?dú)飧卓赡芴峁┎涣?/p>

49、固定拉深筋或保持邊緣固定的力。</p><p>　　高強(qiáng)度鋼拉深筋不應(yīng)該在拉伸模具的轉(zhuǎn)角處延長(zhǎng)，這將會(huì)導(dǎo)致金屬流動(dòng)被鎖定和在沖壓件角落處產(chǎn)生開(kāi)裂。拉深筋應(yīng)該“遠(yuǎn)離”轉(zhuǎn)角半徑切線以減小金屬在轉(zhuǎn)角處壓縮,如圖16。</p><p>　　基于高強(qiáng)度鋼的特性、重要部位的幾何結(jié)構(gòu)和生產(chǎn)量，選用好的材料制造模具是必要的。拉深模的表面處理,例如電鍍，可推薦用于外板的應(yīng)用。</p><

50、p><b>　　脹形和翻邊模</b></p><p>　　為了能補(bǔ)償回彈量，用脹形和翻邊模生產(chǎn)的零件必須允許適當(dāng)?shù)倪^(guò)度彎曲?；貜棙O限必須隨材料強(qiáng)度增加而增加;3度適用于低度鋼,但6度或以上適用于高強(qiáng)度鋼。</p><p>　　沖床半徑必須相當(dāng)尖銳。低強(qiáng)度鋼1噸位。高強(qiáng)度鋼可以要求更大半徑,但使保持和實(shí)際生產(chǎn)時(shí)一樣小，可以降低側(cè)壁的回彈。</p>&

51、lt;p>　　翻邊模具間隙必須不超過(guò)一個(gè)金屬厚度間隙以降低回彈及側(cè)壁發(fā)生的卷曲。</p><p>　　脹形和翻邊板材要固定在鑄件里以避免發(fā)生撓曲。</p><p>　　翻邊板材應(yīng)設(shè)計(jì)時(shí)應(yīng)包住和壓住邊緣斷處以設(shè)置中斷和減少回彈。見(jiàn)圖17。</p><p>　　模具強(qiáng)度不能小于低強(qiáng)度模具結(jié)構(gòu)的強(qiáng)度。高強(qiáng)度鋼將會(huì)需要一個(gè)堅(jiān)硬的模具來(lái)抵抗屈曲和相應(yīng)部分的扭曲,尤其是對(duì)

52、集中力處或冒形截面部分。這部分在成形多個(gè)毛坯時(shí)也會(huì)引起嚴(yán)重的模具損壞</p><p><b>　　剪切模具</b></p><p>　　為了降低噸位要求和延長(zhǎng)模具壽命,十二英寸長(zhǎng)的金屬至少修剪四到六次。</p><p>　　為了減少模具的維修,最大修剪角應(yīng)該在5°角到10°，應(yīng)該低于使用低碳鋼的角度。修剪鋼材要固定在鑄件中以

53、避免鑄件撓曲。模具間隙應(yīng)該是7%到10%的金屬厚度。</p><p><b>　　拉延筋的類型</b></p><p>　　傳統(tǒng)的拉延筋 高強(qiáng)度拉延筋</p><p><b>　　帶壓邊圈拉延模具</b></p><p>　　1.提供一個(gè)垂直的臺(tái)階來(lái)強(qiáng)化和

54、壓制邊緣,同時(shí)防止側(cè)壁的卷曲以及回彈。</p><p>　　2.增加強(qiáng)化暗褶有助于維持一個(gè)90度邊。</p><p>　　3.通過(guò)沿邊緣添加一個(gè)橫向的臺(tái)階、能強(qiáng)化邊緣并減少回彈。</p><p>　　4.上邊緣金屬的補(bǔ)充使得額外的壓力能夠進(jìn)一步應(yīng)用于形成的半徑上。</p><p>　　第五節(jié) 高強(qiáng)鋼模具的模具調(diào)試</p><

55、;p>　　對(duì)模具調(diào)試的一般準(zhǔn)則</p><p><b>　　拉深模具</b></p><p>　　為了控制高強(qiáng)度鋼成型控制并減少板料邊緣的彎曲，在高強(qiáng)度鋼成型時(shí)壓力和噸位高于一般情況是必要的。在某些情況下，為了達(dá)到需要的壓邊力和控制力可以用一種雙作用壓力墊或液壓墊。</p><p>　　高強(qiáng)度鋼拉深模操作時(shí)需要用于制定極端的壓力鋼板潤(rùn)滑劑

56、，機(jī)油對(duì)于大多數(shù)應(yīng)用將不提供足夠的潤(rùn)滑性。預(yù)先潤(rùn)滑或干膜潤(rùn)滑油對(duì)拉深過(guò)程控制有必要的作用。</p><p><b>　　拉伸成型</b></p><p>　　對(duì)于有高強(qiáng)度的高強(qiáng)度鋼定位調(diào)整桿可能需要修改以避免斷裂或撕裂。開(kāi)放側(cè)面轉(zhuǎn)角半徑的筋和擴(kuò)大轉(zhuǎn)角半徑將避免高強(qiáng)度鋼板的開(kāi)裂。定位調(diào)整桿應(yīng)連續(xù)圍繞在延伸模的延伸方向上。</p><p>　　延伸

57、模對(duì)于大型嵌板,如車(chē)頂或外罩，彈性的回復(fù)可能導(dǎo)致板面的收縮,以至于與凸模和翻邊模不匹配。通過(guò)添加一個(gè)因素的來(lái)增大拉深模具或翻邊部分尺寸來(lái)糾正這個(gè)問(wèn)題。這個(gè)“添加的因素”是在該中心的側(cè)面和前面增加不超過(guò)2.5毫米,沖頭上轉(zhuǎn)角處部分的錐度是0，在總的翻邊模中，通過(guò)邊界部分的剖面,增加的部分被移走。</p><p><b>　　脹形和翻邊模</b></p><p>　　沖頭

58、半徑應(yīng)比較突出尖銳，低強(qiáng)度鋼用1或2噸位。H.S.S.可能需要更大半徑,但減小到使用時(shí)能減少側(cè)壁回彈。</p><p>　　在任何平板翻邊中翻邊鋼材會(huì)影響回彈和側(cè)壁的卷曲。半徑應(yīng)該也小到可以減少邊緣的回彈。</p><p>　　過(guò)度彎曲時(shí)回彈補(bǔ)償必須隨抗拉強(qiáng)度增加而增加:3度對(duì)于低強(qiáng)度鋼是一種標(biāo)準(zhǔn),但6度或以上將會(huì)被用于H.S.S。</p><p>　　翻邊模模具間

59、隙應(yīng)該緊湊,保持間隙不超過(guò)一個(gè)金屬厚度以減少回彈及側(cè)壁的卷曲。</p><p><b>　　剪切模</b></p><p>　　降低噸位要求和延長(zhǎng)模具壽命,十二英寸長(zhǎng)的金屬至少修剪四到六次。</p><p>　　對(duì)于高強(qiáng)度鋼模具間隙應(yīng)在7% - 10%的金屬厚度。</p><p>　　減少模具的維修,最大修剪角應(yīng)該在5&

60、#176;角到10°，應(yīng)該低于對(duì)低碳鋼的使用角度。修剪鋼材要固定在鑄件中以避免在鑄件撓曲。</p><p>　　當(dāng)使用加熱可硬化鋼材的模具試用</p><p>　　為了獲得使用BHS的最大值,模具應(yīng)進(jìn)行如下:在行任何模具重新工作前都必須嘗試分析圓網(wǎng)格。模具可作為一個(gè)參考網(wǎng)格板料、模具可修改提供的最小二軸的伸展2.0%。延伸模或拉伸模具最適合該材料。</p><

61、p>　　粗糙度或功能調(diào)試,它可以用低碳鋼增加6% -8%標(biāo)準(zhǔn)來(lái)來(lái)表現(xiàn)通常模具的準(zhǔn)備過(guò)程。這能減輕在每個(gè)模具調(diào)試時(shí)BHS得到強(qiáng)化時(shí)的復(fù)雜情況。這一現(xiàn)象的原因可能是時(shí)間滯后,通常一個(gè)板料之間發(fā)生的形成及其用于下一個(gè)操作。</p><p>　　當(dāng)整個(gè)系列的模具已準(zhǔn)備就緒，所有的模具必須設(shè)置在一條線上。板料能在所有的模具連續(xù)操作。這將避免一些加固效果的時(shí)間延遲操作,可以引起沖壓件之間變化。如果這個(gè)過(guò)程是不被允許的那

62、么尺寸的延伸將是最困難的。</p><p>　　BHS的變化會(huì)導(dǎo)致邊緣尺寸的變化,因?yàn)殡S時(shí)間回彈將隨強(qiáng)度的增加而增加。這就是為什么讓板料能連續(xù)通過(guò)模具各部分，對(duì)一個(gè)成功的檢查來(lái)說(shuō)是至關(guān)重要的。</p><p><b>　　部分新產(chǎn)品引入</b></p><p>　　為了減少新產(chǎn)品引入時(shí)間和消除幾個(gè)小時(shí)的調(diào)試時(shí)間,就要考慮功能建設(shè)所有的優(yōu)勢(shì)。這個(gè)

63、應(yīng)用程序被證明能節(jié)省時(shí)間和金錢(qián)通過(guò)專注于一個(gè)可接受的半成品,而不是迫使每個(gè)沖壓分開(kāi)進(jìn)行。這些零件是最容易改變來(lái)適應(yīng)半成品進(jìn)行相應(yīng)的修正尺寸的目標(biāo)。這些部分并不足以影響半成品質(zhì)量，但是細(xì)節(jié)部分規(guī)格被修改。如果將這種程序用于高強(qiáng)度鋼沖壓件新產(chǎn)品引入將會(huì)消耗過(guò)多時(shí)間。</p><p>　　在功能的建立中除了節(jié)省時(shí)間和模具調(diào)試成本,降低零件變化都有可能實(shí)現(xiàn)。模具制造商所面臨兩個(gè)尺寸上的挑戰(zhàn)：當(dāng)?shù)谝淮螄L試模具時(shí)相對(duì)于公稱規(guī)

64、格降低尺寸上的變化,降低了各部分間的短期尺寸變化。首要任務(wù)是要先減小零件間變化和偏差。這個(gè)策略一個(gè)強(qiáng)有力的論點(diǎn)認(rèn)為偏離標(biāo)稱是被允許的直到零件尺寸上一致可以評(píng)估。盡管很多測(cè)試點(diǎn)偏離標(biāo)準(zhǔn)位置有的甚至超過(guò)偏差極限但在結(jié)果上它們尺寸上是一致的。在許多情況下當(dāng)改變模具尺寸使它接近標(biāo)準(zhǔn)值,它們變得不穩(wěn)定甚至導(dǎo)致部分間更大的變化。這功能建設(shè)理論評(píng)估零件變穩(wěn)定后可接受程度,在小尺寸上的進(jìn)行改變。即使功能的建立在模具重做時(shí)也會(huì)有大偏差或臨界尺寸出現(xiàn)?；?/p>