機械加工外文翻譯

1、<p><b>　　附錄一</b></p><p><b>　　霍斯金斯.喬賽</b></p><p>　　機械加工是所有制造過程中最普遍使用的而且是最重要的方法。機械加工過程是一個產(chǎn)生形狀的過程,在這過程中,驅(qū)動裝置使工件上的一些材料以切屑的形式被去除。盡管在某些場合,工件無承受情況下,使用移動式裝備來實現(xiàn)加工,但大多數(shù)的機械加工是通

2、過既支承工件又支承刀具的裝備來完成。</p><p>　　機械加工在知道過程中具備兩方面。小批生產(chǎn)低費用。對于鑄造、鍛造和壓力加工,每一個要生產(chǎn)的具體工件形狀,即使是一個零件,幾乎都要花費高額的加工費用?？亢附觼懋a(chǎn)生的結(jié)構(gòu)形狀，在很大程度上取決于有效的原材料的形式。一般來說，通過利用貴重設(shè)備而又無需特種加工條件下，幾乎可以以任何種類原材料開始，借助機械加工把原材料加工成任意所需要的結(jié)構(gòu)形狀,只要外部尺寸足夠大,那

3、都是可能的。因此對于生產(chǎn)一個零件,甚至當零件結(jié)構(gòu)及要生產(chǎn)的批量大小上按原來都適于用鑄造、鍛造或者壓力加工來生產(chǎn)的,但通常寧可選擇機械加工。 </p><p>　　基本的機械加工參數(shù) </p><p>　　切削中工件與刀具的基本關(guān)系是以以下四個要素來充分描述的,刀具的幾,何形狀,切削速度,進給速度和吃刀深度。</p><p>　　切削刀具必須用一種合適的材料來制造,

4、它必須是強固、韌性好、堅硬而且耐磨的。刀具的幾何形狀——以刀尖平面和刀具角為特征——對于每一種切削工藝都必須是正確的。 </p><p>　　切削速度是切削刃通過工件表面的速率，它是以每分鐘英寸來表示。為了有效地加工,切削速度高低必須適應(yīng)特定的工件——刀具配合。一般來說,工件材料越硬,速度越低。 </p><p>　　進給速度是刀具切進工件的速度。若工件或刀具作旋轉(zhuǎn)運動，進給量是以每轉(zhuǎn)轉(zhuǎn)過

5、的英寸數(shù)目來度量的。當?shù)毒呋蚬ぜ魍鶑?fù)運動時，進給量是以每一行程走過的英寸數(shù)度量的。一般來說,在其他條件相同時,進給量與切削速度成反比。 </p><p>　　吃刀深度——以英寸計——是刀具進入工件的距離。它等于旋削中的切屑寬度或者等于線性切削中的切屑的厚度。粗加工比起精加工來，吃刀深度較深。 </p><p>　　切削參數(shù)的改變對切削溫度的影響</p><p>　

6、　實質(zhì)上由于在金屬切削中所做的全部功能都被轉(zhuǎn)化為熱,那就可以預(yù)料,被切離金屬的單位體積功率消耗曾家的這些因素就將使切削溫度升高。這樣刀具前角的增加而所有其他參數(shù)不變時,將使切離金屬的單位體積所耗功率減小,因而切削溫度也將降低。當考慮到未變形切屑厚度增加和切削速度,這情形就更是復(fù)雜。未變形切屑厚度的增加趨勢必導(dǎo)致通過工件的熱的總數(shù)上產(chǎn)生比例效應(yīng),刀具和切屑仍保持著固定的比例,而切削溫度變化傾向于降低。然而切削速度的增加,傳導(dǎo)到工件上的熱的

7、數(shù)量減少而這又增加主變形區(qū)中的切屑溫升。進而副變形區(qū)勢必更小,這將在該區(qū)內(nèi)產(chǎn)生升溫效應(yīng)。其他切削參數(shù)的變化,實質(zhì)上對于被切離的單位體積消耗上并沒有什么影響,因此實際上對切削溫度沒有什么作用。因為事實已經(jīng)表明,切削溫度即使有小小的變化對刀具磨損率都將有實質(zhì)意義的影響作用。這表明如何人從切削參數(shù)來確定切削溫度那是很合適的。 </p><p>　　為著測定高速鋼刀具溫度的最直接和最精確的方法是W&T法,這方法也

8、就是可提供高速鋼刀具溫度分布的詳細信息的方法。該項技術(shù)是建立在高速鋼刀具截面金相顯微測試基礎(chǔ)上,目的是要建立顯微結(jié)構(gòu)變化與熱變化規(guī)律圖線關(guān)系式。當要加工廣泛的工件材料時,Trent已經(jīng)論述過測定高速鋼刀具的切削溫度及溫度分布的方法。這項技術(shù)由于利用電子顯微掃描技術(shù)已經(jīng)進一步發(fā)展,目的是要研究將已回過火和各種馬氏體結(jié)構(gòu)的高速鋼再回火引起的微觀顯微結(jié)構(gòu)變化情況。這項技術(shù)亦用于研究高速鋼單點車刀和麻花鉆的溫度分布。 </p>&

9、lt;p><b>　　刀具磨損 </b></p><p>　　從已經(jīng)被處理過的無數(shù)脆裂和刃口裂紋的刀具中可知,刀具磨損基本上有三種形式:后刀面磨損,前刀面磨損和V型凹口磨損。后刀面磨損既發(fā)生在主刀刃上也發(fā)生副刀刃上。關(guān)于主刀刃,因其擔負切除大部金屬切屑任務(wù),這就導(dǎo)致增加切削力和提高切削溫度,如果聽任而不加以檢查處理,那可能導(dǎo)致刀具和工件發(fā)生振動且使有效切削的條件可能不再存在。關(guān)于副刀

10、刃,那是決定著工件的尺寸和表面光潔度的,后刀面磨損可能造成尺寸不合格的產(chǎn)品而且表面光潔度也差。在大多數(shù)實際切削條件下,由于主前刀面先于副前刀面磨損,磨損到達足夠大時,刀具將實效,結(jié)果是制成不合格零件。 </p><p>　　由于刀具表面上的應(yīng)力分布不均勻,切屑和前刀面之間滑動接觸區(qū)應(yīng)力,在滑動接觸區(qū)的起始處最大,而在接觸區(qū)的尾部為零,這樣磨蝕性磨損在這個區(qū)域發(fā)生了。這是因為在切削卡住區(qū)附近比刀刃附近發(fā)生更嚴重的磨

11、損,而刀刃附近因切屑與前刀面失去接觸而磨損較輕。這結(jié)果離切削刃一定距離處的前刀面上形成麻點凹坑,這些通常被認為是前刀面的磨損。通常情況下,這磨損橫斷面是圓弧形的。在許多情況中和對于實際的切削狀況而言,前刀面磨損比起后刀面磨損要輕，因此后刀面磨損更普遍地作為刀具失效的尺度標志。然而因許多作者已經(jīng)表示過的那樣在增加切削速度情況下，前刀面上的溫度比后刀面上的溫度升得更快,而且又因任何形式的磨損率實質(zhì)上是受到溫度變化的重大影響。因此前刀面的磨損

12、通常在高速切削時發(fā)生的。 </p><p>　　如果任何進行性形式的磨損任由繼續(xù)發(fā)展,最終磨損速率明顯地增加而刀具將會有摧毀性失效破壞,即刀具將不能再用作切削,造成工件報廢,那算是好的,嚴重的可造成機床破壞。對于各種硬質(zhì)合金刀具和對于各種類型的磨損,在發(fā)生嚴重失效前,就認為已達到刀具的使用壽命周期的終點。然而對于各種高速鋼刀具,其磨損是屬于非均勻性磨損,已經(jīng)發(fā)現(xiàn):當其磨損允許連續(xù)甚至到嚴重失效開始,最有意義的是該

13、刀具可以獲得重磨使用,當然,在實際上,切削時間遠比使用到失效的時間短。以下幾種現(xiàn)象之一均是刀具嚴重失效開始的特征,最普遍的是切削力突然增加,在工件上出現(xiàn)燒損環(huán)紋和噪音嚴重增加等。 </p><p><b>　　自動夾具設(shè)計 </b></p><p>　　用做裝配設(shè)備的傳統(tǒng)同步夾具把零件移動到夾具中心上,以確保零件從傳送機上或從設(shè)備盤上取出后置于已定位置上。然而在某些

14、應(yīng)用場合、強制零件移動到中心線上時,可能引起零件或設(shè)備破壞。當零件易損而且小小振動可能導(dǎo)致報廢時,或當其位置是由機床主軸或模具來具體時,再或者當公差要求很精密時,那寧可讓夾具去適應(yīng)零件位置,而不是相反。為著這些工作任務(wù)美國俄亥俄州Elyria的Zaytran公司已經(jīng)開發(fā)了一般性功能數(shù)據(jù)的非同步西類柔順性夾具。因為夾具作用力和同步化裝置是各自獨立的,該同步裝置可以用精密的滑移裝置來替換而不影響夾具作用力。夾具規(guī)格范圍是從0.2英寸行程,5

15、英鎊夾緊力到6英寸行程、400英寸夾緊力。 </p><p>　　根據(jù)它們?nèi)犴樞?夾具可以分為:專用夾具、組合夾具、標準夾具、高柔性夾具。柔性夾具是以它們對不同工件的高適應(yīng)性和以少更換低費用為特征的。 </p><p>　　結(jié)構(gòu)形式可變換的柔性夾具裝有可變更結(jié)構(gòu)排列的零件(例如針形頰板,多片式零件和片狀頰板),標準工件的非專用夾持或夾緊元件(例如:啟動標準夾持夾具和有可移動元件的夾具配套

16、件),或者裝有陶瓷或硬化了的中介物質(zhì)(如:流動粒子床夾具和熱夾具緊夾具)。為了生產(chǎn),零件要在夾具中被緊固,需要產(chǎn)生夾緊作用,其有幾個與夾具柔順性無關(guān)的步驟:</p><p>　　在充分準備了構(gòu)造方案和一批材料情況下,在完成首次組裝可以成功實現(xiàn)</p><p>　　節(jié)約時間達60%。 </p><p>　　因此夾具機構(gòu)造型過程的目的是產(chǎn)生合適的編程文件。 </

17、p><p><b>　　附錄二</b></p><p>　　Introduction of Machining</p><p>　　Hoskins.Josiah</p><p>　　all machining process for the production of the most commonly used and m

18、ost important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circum

19、stances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete. </p><p>　　Machining know t

20、he process has two aspects. Small group of low-cost production. For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost have to spend the high cost o

21、f processing. Welding to rely on the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditio

22、ns, can be almost any type of raw materials,</p><p>　　Primary Cutting Parameters </p><p>　　Cutting the work piece and tool based on the basic relationship between the following four elements to

23、fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool. </p><p>　　Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard an

24、d wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct. </p><p>　　Cutting speed is the cutting edge of work piece surface rate, it is

25、 inches per minute to show. In order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more hard work piece material, the lower the rate. </p>&l

26、t;p>　　Depth of penetration of a cutting tool -- to inches dollars -- is the tool to the work piece distance. Rotary cutting it to the chip or equal to the width of the linear cutting chip thickness. Rough than finishi

27、ng, deeper penetration of a cutting tool depth. </p><p>　　Wears of Cutting Tool </p><p>　　We already have been processed and the rattle of the countless cracks edge tool, we learn that tool wear

28、 are basically three forms : flank wear, the former flank wear and V-Notch wear. Flank wear occurred in both the main blade occurred vice blade. On the main blade, shoulder removed because most metal chip mandate, which

29、resulted in an increase cutting force and cutting temperature increase, If not allowed to check, That could lead to the work piece and the tool vibration and provide for effici</p><p>　　As Tool stress on the

30、 surface uneven, chip and flank before sliding contact zone between stress, in sliding contact the start of the largest, and in contact with the tail of zero, so abrasive wear in the region occurred. This is because the

31、card cutting edge than the nearby settlements near the more serious wear, and bladed chip due to the vicinity of the former flank and lost contact wear lighter. This results from a certain distance from the cutting edge

32、of the surface formed before the knife </p><p>　　If any form of sexual allowed to wear, eventually wear rate increase obviously will be a tool to destroy failure destruction, that will no longer tool for cut

33、ting, cause the work piece scrapped, it is good, can cause serious damage machine. For various carbide cutting tools and for the various types of wear, in the event of a serious lapse, on the tool that has reached the en

34、d of the life cycle. But for various high-speed steel cutting tools and wear belonging to the non-uniformity of wear, has </p><p>　　The Effect of Changes in Cutting Parameters on Cutting Temperatures </p&

35、gt;<p>　　In metal cutting operations heat is generated in the primary and secondary deformation zones and this results in a complex temperature distribution throughout the tool, workpiece and chip. A typical set o

36、f isotherms is shown in figure where it can be seen that, as could be expected, there is a very large temperature gradient throughout the width of the chip as the workpiece material is sheared in primary deformation and

37、there is a further large temperature in the chip adjacent to the face as the</p><p>　　e assessed from cutting data. </p><p>　　The most direct and accurate method for measuring temperatures in h

38、igh-speed-steel cutting tools is that of Wright & Trent which also yields detailed information on temperature distributions in high-speed-steel tools which relates microstructural changes to thermal history. </p&g

39、t;<p>　　Trent has described measurements of cutting temperatures and temperature distributions for high-speed-steel tools when machining a wide range of workpiece materials. This technique has been further develop

40、ed by using scanning electron microscopy to study fine-scale microstructural changes srising from over tempering of the tempered martensitic matrix of various high-speed-steels. This technique has also been used to study

41、 temperature distributions in both high-speed-steel single point turning to</p><p>　　Automatic Fixture Design </p><p>　　Assembly equipment used in the traditional synchronous fixture put parts o

42、f the fixture mobile center, to ensure that components from transmission from the plane or equipment plate placed after removal has been scheduled for position. However, in certain applications, mobile mandatory parts of

43、 the center line, it may cause parts or equipment damage. When parts vulnerability and may lead to a small vibration abandoned, or when their location is by machine spindle or specific to die, Tolerance aga</p>&l

44、t;p>　　The characteristics of modern production is becoming smaller and smaller quantities and product specifications biggest changes. Therefore, in the final stages of production, assembly of production,quantity and p

45、roduct design changes appear to be particularly vulnerable. This situation is forcing many companies to make greater efforts to rationalize the extensive reform and the previously mentioned case of assembly automati on.

46、Despite flexible fixture behind the rapid development of flexible tra</p><p>　　According to their flexibility and fixture can be divided into: special fixture, the fixture combinations, the standard fixture,

47、 high flexible fixture. Flexible fixture on different parts of their high adaptability and the few low-cost replacement for the characteristic. </p><p>　　Forms can transform the structure of the flexible f

48、ixture can be installed with the change of structure components (such as needle cheek plate, Multi-chip components and flake cheek plate), a non-standard work piece gripper or clamping elements (for example : commencemen

49、t standard with a clamping fixture and mobile components fixture supporting documents), or with ceramic or hardening of the intermediary substances (such as : Mobile particle bed fixture and heat fixture tight fixture).

50、To produc</p><p>　　According to the processing was part of that foundation and working characteristics to determine the work piece fixture in the required position, then need to select some stability flat c

51、ombination, These constitute a stable plane was fixed in the work piece fixture setposition on the clamp-profile structure, all balanced and torque, it has also ensured that the work features close to the work piece. Fi

52、nally, it must be calculated and adjusted, assembly or disassembly be standard fixture compo</p><p>　　Fully prepared to structure programs and the number of material circumstances, the completion of the firs