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本科生畢業(yè)設(shè)計(jì) (論文)
外 文 翻 譯
原 文 標(biāo) 題
Introduction of Machining
譯 文 標(biāo) 題
加工基礎(chǔ)
作者所在系別
機(jī)電工程學(xué)院
作者所在專(zhuān)業(yè)
機(jī)械設(shè)計(jì)制造及其自動(dòng)化
作者所在班級(jí)
B13113
作 者 姓 名
朱凱
作 者 學(xué) 號(hào)
20134011323
指導(dǎo)教師姓名
趙忠澤
指導(dǎo)教師職稱(chēng)
副教授
完 成 時(shí) 間
2017
年
3
月
北華航天工業(yè)學(xué)院教務(wù)處制
譯文標(biāo)題
加工基礎(chǔ)
原文標(biāo)題
Introduction of Machining
作 者
Hoskins, Josiah
譯 名
霍斯金斯·喬賽亞
國(guó) 籍
美國(guó)
原文出處
百度文庫(kù)
譯文：
加工基礎(chǔ)
作為產(chǎn)生形狀的一種加工方法，機(jī)械加工是所有制造過(guò)程中最普遍使用的而且是最重要的方法。機(jī)械加工過(guò)程是一個(gè)產(chǎn)生形狀的過(guò)程，在這過(guò)程中，驅(qū)動(dòng)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(chǎng)合，工件無(wú)承受情況下，使用移動(dòng)式裝備來(lái)實(shí)現(xiàn)加工，但大多數(shù)的機(jī)械加工是通過(guò)既支承工件又支承刀具的裝備來(lái)完成。
機(jī)械加工在知道過(guò)程中具備兩方面。小批生產(chǎn)低費(fèi)用。對(duì)于鑄造、鍛造和壓力加工，每一個(gè)要生產(chǎn)的具體工件形狀，即使是一個(gè)零件，幾乎都要花費(fèi)高額的加工費(fèi)用?？亢附觼?lái)產(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(lái)說(shuō)，通過(guò)利用貴重設(shè)備而又無(wú)需特種加工條件下，幾乎可以以任何種類(lèi)原材料開(kāi)始，借助機(jī)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，那都是可能的。因此對(duì)于生產(chǎn)一個(gè)零件，甚至當(dāng)零件結(jié)構(gòu)及要生產(chǎn)的批量大小上按原來(lái)都適于用鑄造、鍛造或者壓力加工來(lái)生產(chǎn)的，但通常寧可選擇機(jī)械加工。
嚴(yán)密的精度和良好的表面光潔度，機(jī)械加工的第二方面用途是建立在高精度和可能的表面光潔度基礎(chǔ)上。許多零件，如果用別的其他方法來(lái)生產(chǎn)屬于大批量生產(chǎn)的話，那么在機(jī)械加工中則是屬于低公差且又能滿足要求的小批量生產(chǎn)了。另方面，許多零件靠較粗的生產(chǎn)加工工藝提高其一般表面形狀，而僅僅是在需要高精度的且選擇過(guò)的表面才進(jìn)行機(jī)械加工。例如內(nèi)螺紋，除了機(jī)械加工之外，幾乎沒(méi)有別的加工方法能進(jìn)行加工。又如已鍛工件上的小孔加工，也是被鍛后緊接著進(jìn)行機(jī)械加工才完成的。
基本的機(jī)械加工參數(shù)
切削中工件與刀具的基本關(guān)系是以以下四個(gè)要素來(lái)充分描述的，刀具的幾何形狀，切削速度，進(jìn)給速度，和吃刀深度。
切削刀具必須用一種合適的材料來(lái)制造，它必須是強(qiáng)固、韌性好、堅(jiān)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(duì)于每一種切削工藝都必須是正確的。
切削速度是切削刃通過(guò)工件表面的速率，它是以每分鐘英寸來(lái)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(lái)說(shuō)，工件材料越硬，速度越低。
進(jìn)給速度是刀具切進(jìn)工件的速度。若工件或刀具作旋轉(zhuǎn)運(yùn)動(dòng)，進(jìn)給量是以每轉(zhuǎn)轉(zhuǎn)過(guò)的英寸數(shù)目來(lái)度量的。當(dāng)?shù)毒呋蚬ぜ魍鶑?fù)運(yùn)動(dòng)時(shí)，進(jìn)給量是以每一行程走過(guò)的英寸數(shù)度量的。一般來(lái)說(shuō)，在其他條件相同時(shí)，進(jìn)給量與切削速度成反比。
吃刀深度——以英寸計(jì)——是刀具進(jìn)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(lái)，吃刀深度較深。
切削參數(shù)的改變對(duì)切削溫度的影響
金屬切削操作中，熱是在主變形區(qū)和副變形區(qū)發(fā)生的。這結(jié)果導(dǎo)致復(fù)雜的溫度分布遍及刀具、工件和切屑。圖中顯示了一組典型等溫曲線，從中可以看出，像所能預(yù)料的那樣，當(dāng)工件材料在主變形區(qū)被切削時(shí)，沿著整個(gè)切屑的寬度上有著很大的溫度梯度，而當(dāng)在副變形區(qū)，切屑被切落時(shí)，切屑附近的前刀面上就有更高的溫度。這導(dǎo)致了前刀面和切屑離切削刃很近的地方切削溫度較高。
實(shí)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(shí)，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(dāng)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(shì)必導(dǎo)致通過(guò)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)到工件上的熱的數(shù)量減少而這又增加主變形區(qū)中的切屑溫升。進(jìn)而副變形區(qū)勢(shì)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(shí)質(zhì)上對(duì)于被切離的單位體積消耗上并沒(méi)有什么影響，因此實(shí)際上對(duì)切削溫度沒(méi)有什么作用。因?yàn)槭聦?shí)已經(jīng)表明，切削溫度即使有小小的變化對(duì)刀具磨損率都將有實(shí)質(zhì)意義的影響作用。這表明如何人從切削參數(shù)來(lái)確定切削溫度那是很合適的。
為著測(cè)定高速鋼刀具溫度的最直接和最精確的方法是 W&T 法，這方法也就是可提供高速鋼刀具溫度分布的詳細(xì)信息的方法。該項(xiàng)技術(shù)是建立在高速鋼刀具截面金相顯微測(cè)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(dāng)要加工廣泛的工件材料時(shí)，Trent 已經(jīng)論述過(guò)測(cè)定高速鋼刀具的切削溫度及溫度分布的方法。這項(xiàng)技術(shù)由于利用電子顯微掃描技術(shù)已經(jīng)進(jìn)一步發(fā)展，目的是要研究將已回過(guò)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(xiàng)技術(shù)亦用于研究高速鋼單點(diǎn)車(chē)刀和麻花鉆的溫度分布。
刀具磨損
從已經(jīng)被處理過(guò)的無(wú)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(dān)負(fù)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(tīng)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(dòng)且使有效切削的條件可能不再存在。關(guān)于副刀刃，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(shí)際切削條件下，由于主前刀面先于副前刀面磨損，磨損到達(dá)足夠大時(shí)，刀具將實(shí)效，結(jié)果是制成不合格零件。
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(dòng)接觸區(qū)應(yīng)力，在滑動(dòng)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(gè)區(qū)域發(fā)生了。這是因?yàn)樵谇邢骺ㄗ^(qū)附近比刀刃附近發(fā)生更嚴(yán)重的磨損，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(diǎn)凹坑，這些通常被認(rèn)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(duì)于實(shí)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(biāo)志。然而因許多作者已經(jīng)表示過(guò)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(shí)質(zhì)上是受到溫度變化的重大影響。因此前刀面的磨損通常在高速切削時(shí)發(fā)生的。
刀具的主后刀面磨損帶的尾部是跟未加工過(guò)的工件表面相接觸，因此后刀面磨損比沿著磨損帶末端處更為明顯，那是最普通的。這是因?yàn)榫植啃?yīng)，這像未加工表面上的已硬化層，這效應(yīng)是由前面的切削引起的工件硬化造成的。不只是切削，還有像氧化皮，刀刃產(chǎn)生的局部高溫也都會(huì)引起這種效應(yīng)。這種局部磨損通常稱(chēng)作為凹坑性磨損，而且偶爾是非常嚴(yán)重的。盡管凹坑的出現(xiàn)對(duì)刀具的切削性質(zhì)無(wú)實(shí)質(zhì)意義的影響，但凹坑常常逐漸變深，如果切削在繼續(xù)進(jìn)行的話，那么刀具就存在斷裂的危機(jī)。
如果任何進(jìn)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(huì)有摧毀性失效破壞，即刀具將不能再用作切削，造成工件報(bào)廢，那算是好的，嚴(yán)重的可造成機(jī)床破壞。對(duì)于各種硬質(zhì)合金刀具和對(duì)于各種類(lèi)型的磨損，在發(fā)生嚴(yán)重失效前，就認(rèn)為已達(dá)到刀具的使用壽命周期的終點(diǎn)。然而對(duì)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(dāng)其磨損允許連續(xù)甚至到嚴(yán)重失效開(kāi)始，最有意義的是該刀具可以獲得重磨使用，當(dāng)然，在實(shí)際上，切削時(shí)間遠(yuǎn)比使用到失效的時(shí)間短。以下幾種現(xiàn)象之一均是刀具嚴(yán)重失效開(kāi)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(yán)重增加等。
自動(dòng)夾具設(shè)計(jì)
用做裝配設(shè)備的傳統(tǒng)同步夾具把零件移動(dòng)到夾具中心上，以確保零件從傳送機(jī)上或從設(shè)備盤(pán)上取出后置于已定位置上。然而在某些應(yīng)用場(chǎng)合、強(qiáng)制零件移動(dòng)到中心線上時(shí)，可能引起零件或設(shè)備破壞。當(dāng)零件易損而且小小振動(dòng)可能導(dǎo)致報(bào)廢時(shí)，或當(dāng)其位置是由機(jī)床主軸或模具來(lái)具體時(shí)，再或者當(dāng)公差要求很精密時(shí)，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(guó)俄亥俄州 Elyria 的 Zaytran 公司已經(jīng)開(kāi)發(fā)了一般性功能數(shù)據(jù)的非同步西類(lèi)柔順性?shī)A具。因?yàn)閵A具作用力和同步化裝置是各自獨(dú)立的，該同步裝置可以用精密的滑移裝置來(lái)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英鎊夾緊力到 6 英寸行程、400 英寸夾緊力。
現(xiàn)代生產(chǎn)的特征是批量變得越來(lái)越小而產(chǎn)品的各種規(guī)格變化最大。因此，生產(chǎn)的最后階段，裝配因生產(chǎn)計(jì)劃、批量和產(chǎn)品設(shè)計(jì)的變更而顯得特別脆弱。這種情形正迫使許多公司更多地致力于廣泛的合理化改革和前面提到過(guò)情況那樣裝配自動(dòng)化。盡管柔性?shī)A具的發(fā)展很快落后與柔性運(yùn)輸處理裝置的發(fā)展，如落后于工業(yè)機(jī)器人的發(fā)展，但仍然試圖指望增加夾具的柔順性。事實(shí)上夾具的重要的裝置——生產(chǎn)裝置的專(zhuān)向投資就加強(qiáng)了使夾具更加柔性化在經(jīng)濟(jì)上的支持。
根據(jù)它們?nèi)犴樞?，夾具可以分為，專(zhuān)用夾具、組合夾具、標(biāo)準(zhǔn)夾具、高柔性?shī)A具。柔性?shī)A具是以它們對(duì)不同工件的高適應(yīng)性和以少更換低費(fèi)用為特征的。
結(jié)構(gòu)形式可變換的柔性?shī)A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(biāo)準(zhǔn)工件的非專(zhuān)用夾持或夾緊元件（例如：?jiǎn)?dòng)標(biāo)準(zhǔn)夾持夾具和帶有可移動(dòng)元件的夾具配套件，）或者裝有陶瓷或硬化了的中介物質(zhì)（如：流動(dòng)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(gè)與夾具柔順性無(wú)關(guān)的步驟：
根據(jù)被加工的即基礎(chǔ)的部分和工作特點(diǎn)，確定工件在夾具中的所需的位置，接著必須選擇若干穩(wěn)定平面的組合，這些穩(wěn)定平面就構(gòu)成工件被固定在夾具中確定位置上的夾持狀輪廓結(jié)構(gòu)，均衡所有各力和力矩，而且保證接近工件工作特點(diǎn)。最后，必須計(jì)算、調(diào)整、組裝可拆裝的或標(biāo)準(zhǔn)夾具元件的所需位置以便使工件牢牢地被夾緊在夾具中。依據(jù)這樣的程序，夾具的輪廓結(jié)構(gòu)和裝合的規(guī)劃和記錄過(guò)程可以進(jìn)行自動(dòng)化控制。
結(jié)構(gòu)造型任務(wù)就是要產(chǎn)生若干穩(wěn)定平面的組合，這樣在這些平面上的各夾緊力將使工件和夾具穩(wěn)定。按慣例，這個(gè)任務(wù)可用人—機(jī)對(duì)話即幾乎完全自動(dòng)化的方式來(lái)完成。一人—機(jī)對(duì)話即以自動(dòng)化方式確定夾具結(jié)構(gòu)造型的優(yōu)點(diǎn)是可以有組織有規(guī)劃進(jìn)行夾具設(shè)計(jì)，減少所需的設(shè)計(jì)人員，縮短研究周期和能更好地配置工作條件。簡(jiǎn)言之，可成功地達(dá)到顯著提高夾具生產(chǎn)效率和效益。
在充分準(zhǔn)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(shí)現(xiàn)節(jié)約時(shí)間達(dá) 60%。
因此夾具機(jī)構(gòu)造型過(guò)程的目的是產(chǎn)生合適的編程文件
原文：
Introduction of Machining
Have a shape as a processing method, all machining process for the production of the most commonly used and most 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 circumstances, 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.
Machining know the 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 of 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 conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.
Strict precision and good surface finish, Machining the second purpose is the establishment of the high precision and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production.
Besides, many parts on the production and processing of coarse process to improve its general shape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread,in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.
Primary Cutting Parameters
Cutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.
Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, hard and wear-resistant. Tool geometry -- to the tip plane and cutter angle characteristics -- for each cutting process must be correct.
Cutting speed is the cutting edge of work piece surface rate, it is 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.
Progressive Tool to speed is cut into the work piece speed. If the work piece or tool for rotating movement, feed rate per round over the number of inches to the measurement. When the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to。
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 finishing, deeper penetration of a cutting tool depth.
Wears of Cutting Tool
We already have been processed and the rattle of the countless cracks edge tool, we learn that tool wear 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 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 efficient cutting conditions may no longer exist. Vice-bladed on,it is determined work piece dimensions and surface finish. Flank wear size of the possible failure of the product and surface finish are also inferior. In most actual cutting conditions, as the principal in the former first deputy flank before flank wear, wear arrival enough, Tool will be effective, the results are made unqualified parts.
As Tool stress on the 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 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 of the surface formed before the knife point Ma pit, which is usually considered before wear. Under normal circumstances, this is wear cross-sectional shape of an arc. In many instances and for the actual cutting conditions, the former flank wear compared to flank wear light, Therefore flank wear more generally as a tool failure of scale signs. But because many authors have said in the cutting speed of the increase, Maeto surface temperature than the knife surface temperatures have risen faster. But because any form of wear rate is essentially temperature changes by the significant impact. Therefore, the former usually wear in high-speed cutting happen.
The main tool flank wear the tail is not processed with the work piece surface in contact, Therefore flank wear than wear along with the ends more visible, which is the most common. This is because the local effect, which is as rough on the surface has hardened layer, This effect is by cutting in front of the hardening of t he work piece. Not just cutting, and as oxidation skin, the blade local high temperature will also cause this effect. This partial wear normally referred to as pit sexual wear, but occasionally it is very serious. Despite the emergence of the pits on the Cutting Tool nature is not meaningful impact, but often pits gradually become darker If cutting continued the case, then there cutter fracture crisis.
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 cutting, 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 end of the life cycle. But for various high-speed steel cutting tools and wear belonging to the non-uniformity of wear, has been found : When the wear and even to allow for a serious lapse,the most meaningful is that the tool can re-mill use, of course, In practice, cutting the time to use than the short time lapse. Several phenomena are one tool serious lapse began features : the most common is the sudden increase cutting force, appeared on the work piece burning ring patterns and an increase in noise.
The Effect of Changes in Cutting Parameters on Cutting Temperatures
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 of 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 there is a further large temperature in the chip adjacent to the face as the chip is sheared in secondary deformation. This leads to a maximum cutting temperature a short distance up the face from the cutting edge and a small distance into the chip.
Since virtually all the work done in metal cutting is converted into heat, it could be expected that factors which increase the power consumed per unit volume of metal removed will increase the cutting temperature. Thus an increase in the rake angle, all other parameters remaining constant, will reduce the power per unit volume of metal removed and cutting temperatures will reduce. When considering increase in undeformed chip thickness and cutting speed the situation is more comples. An increase in undeformed chip thickness and cutting speed the situation is more complex. An increase in undeformed chip thickness tends to be a scale effect where the amounts of heat which pass to the workpiece, the tool and chip remain in fixed proportions and the changes in cutting temperature tend to be small. Increase in cutting speed, however, reduce the amount of heat which passes into the workpiece and this increase the temperature rise of the chip in primary deformation. Further, the secondary deformation zone tends to be smaller and this has the effect of increasing the temperatures in this zone. Other changes in cutting parameters have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the power consumed per unit volume of metal removed and consequently have virtually no effect on the cutting temperatures. Since it has been shown that even small changes in cutting temperature have a significant effect on tool wear rate, it is appropriate to indicate how cutting temperatures can be assessed from cutting data.
The most direct and accurate method for measuring temperatures in high-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.
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 developed 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 temperature distributions in both high-speed-steel single point turning tools and twist drills.
Automatic Fixture Design
Assembly equipment used in the traditional synchronous fixture put parts of 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 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 again or when the request is a sophisticated, it would rather let the fixture to adapt to the location of parts, and not the contrary. For these tasks, Elyria, Ohio, the company has developed Zaytran a general non-functional data synchronization West category FLEXIBILITY fixture. Fixture because of the interaction and synchronization devices is independent, The synchronous device can use sophisticated equipment to replace the slip without affecting the fixture force. Fixture specification range from 0.2 inches itinerary, 5 pounds clamping force of the six-inch trip, 400-inch clamping force.
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 product 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. Despite flexible fixture behind the rapid development of flexible transport and handling devices, suchas backward in the development of industrial robots, it is still expected to increase the flexibility fixture. In fact the important fixture devices -- the production of the devices to strengthen investment on the fixture so that more flexibility in economic support holders.
According to their flexibility and fixture can be divided into : special fixture, the fixture combinations, the standard fixture, high flexible fixture. Flexible fixture on different parts of their high adaptability and the few low-cost replacement for the characteristic.
Forms can transform the structure of the flexible fixture 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 : commencement 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). To production, the parts were secured fixture, the need to generate clamping function, its fixture with a few unrelated to the sexual submissive steps :
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 combination, These constitute a stable plane was fixed in the work piece fixture set position on the clamp-profile structure, all balanced and torque, it has also ensured that the work features close to the work piece. Finally, it must be calculated and adjusted, assembly or disassembly be standard fixture components required for the position, so that the work piece firmly by clamping fixture in China. In accordance with this procedure, the outline fixture structure and equipped with the planning and recording process can be automated control.
Structural modeling task is to produce some stable flat combination, Thus, these plane of the work pieces clamping force and will fixture stability. According to usual practice, this task can be human-machine dialogue that is almost completely automated way to completion. A man-machine dialogue that is automated fixture structure modeling to determine the merits can be conducted in an organized and planning fixture design, reduce the amount of the design, shortening the study period and better distribution of work conditions. In short, can be successfully achieved significantly improve fixture efficiency and effectiveness.
Fully prepared to structure programs and the number of material circumstances, the completion of the first successful assembly can save up to 60% of the time.
Therefore fixture process modeling agencies is the purpose of the program have appropriate documents.
指 導(dǎo) 教 師 評(píng) 語(yǔ)
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注：1. 指導(dǎo)教師對(duì)譯文進(jìn)行評(píng)閱時(shí)應(yīng)注意以下幾個(gè)方面：①翻譯的外文文獻(xiàn)與畢業(yè)設(shè)計(jì)（論文）的主題是否高度相關(guān)，并作為外文參考文獻(xiàn)列入畢業(yè)設(shè)計(jì)（論文）的參考文獻(xiàn)；②翻譯的外文文獻(xiàn)字?jǐn)?shù)是否達(dá)到規(guī)定數(shù)量（3 000字以上）；③譯文語(yǔ)言是否準(zhǔn)確、通順、具有參考價(jià)值。
2. 外文原文應(yīng)以附件的方式置于譯文之后。
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