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附錄2Introduciton of MachiningHave a shape as a processing method, all machining process for the production of the most monly 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 plete.Machining know the process has two aspects. Small group of lowcost 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 largescale production, Well Machining is a lowtolerance 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 pletion of the processing.Primary Cutting ParametersCutting 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 wearresistant. 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。在充分準備了構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)節(jié)約時間達60%。一人—機對話即以自動化方式確定夾具結構造型的優(yōu)點是可以有組織有規(guī)劃進行夾具設計,減少所需的設計人員,縮短研究周期和能更好地配置工作條件。結構造型任務就是要產生若干穩(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。最后,必須計算、調整、組裝可拆裝的或標準夾具元件的所需位置,以便使工件牢牢地被夾緊在夾具中。結構形式可變換的柔性夾具裝有可變更結構排列的零件(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帶有可移動元件的夾具配套件),或者裝有陶瓷或硬化了的中介物質(如:流動粒子床夾具和熱夾具緊夾具)。根據(jù)它們柔順性,夾具可以分為:專用夾具、組合夾具、標準夾具、高柔性夾具。盡管柔性夾具的發(fā)展很快落后與柔性運輸處理裝置的發(fā)展,如落后于工業(yè)機器人的發(fā)展,但仍然試圖指望增加夾具的柔順性。因此,生產的最后階段,裝配因生產計劃、批量和產品設計的變更而顯得特別脆弱。5英鎊夾緊力到6英寸行程、400英寸夾緊力。為著這些工作任務,美國俄亥俄州Elyria的Zaytran公司已經開發(fā)了一般性功能數(shù)據(jù)的非同步西類柔順性夾具。然而在某些應用場合、強制零件移動到中心線上時,可能引起零件或設備破壞。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。對于各種硬質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。盡管凹坑的出現(xiàn)對刀具的切削性質無實質意義的影響,但凹坑常常逐漸變深,如果切削在繼續(xù)進行的話,那么刀具就存在斷裂的危機。不只是切削,還有像氧化皮,刀刃產生的局部高溫也都會引起這種效應。刀具的主后刀面磨損帶的尾部是跟未加工過的工件表面相接觸,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。然而因許多作者已經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上是受到溫度變化的重大影響。通常情況下,這磨損橫斷面是圓弧形的。這是因為在切削卡住區(qū)附近比刀刃附近發(fā)生更嚴重的磨損,而刀刃附近因切屑與前刀面失去接觸而磨損較輕。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,結果是制成不合格零件。關于主刀刃,因其擔負切除大部金屬切屑任務,這就導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。刀具磨損從已經被處理過的無數(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。這項技術由于利用電子顯微掃描技術已經進一步發(fā)展,目的是要研究將已回過火和各種馬氏體結構的高速鋼再回火引起的微觀顯微結構變化情況。該項技術是建立在高速鋼刀具截面金相顯微測試基礎上,目的是要建立顯微結構變化與熱變化規(guī)律圖線關系式。為著測定高速鋼刀具溫度的最直接和最精確的方法是Wamp。因為事實已經表明:切削溫度即使有小小的變化對刀具磨損率都將有實質意義的影響作用。進而副變形區(qū)勢必更小,這將在該區(qū)內產生升溫效應。未變形切屑厚度的增加趨勢必導致通過工件的熱的總數(shù)上產生比例效應,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。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。這導致了前刀面和切屑離切削刃很近的地方切削溫度較高。這結果導致復雜的溫度分布遍及刀具、工件和切屑。粗加工比起精加工來,吃刀深度較深。吃刀深度——以英寸計——是刀具進入工件的距離。當?shù)毒呋蚬ぜ魍鶑瓦\動時,進給量是以每一行程走過的英寸數(shù)度量的。進給速度是刀具切進工件的速度。為了有效地加工,切削速度高低必須適應特定的工件——刀具配合。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。基本的機械加工參數(shù)切削中工件與刀具的基本關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。例如內螺紋,除了機械加工之外,幾乎沒有別的加工方法能進行加工。許多零件,如果用別的其他方法來生產屬于大批量生產的話,那么在機械加工中則是屬于低公差且又能滿足要求的小批量生產了。因此對于生產一個零件,甚至當零件結構及要生產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的,但通常寧可選擇機械加工??亢附觼懋a生的結構形狀,在很大程度上取決于有效的原材料的形式。小批生產低費用。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)的機械加工是通過既支承工件又支承刀具的裝備來完成。附錄1加工基礎作為產生形狀的一種加工方法,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。此次畢業(yè)設計能夠順利完成,離不開指導老師。如:沒有考慮電梯的消防功能等。當你對待編程序涉及的事物之間的聯(lián)系及制約了解透徹之時,也就是程序編制完成之時。但當有淺入深,層層漸進地讀完以上程序,又覺得并不是太難。圖410 起動、穩(wěn)速運行、制動加速環(huán)節(jié)梯形圖 梯形圖匯總將開關門,樓層信號,內呼外喚,上行下行,停層,電機控制等局部梯形圖拼在一起就可以得到電梯PLC控制的梯形總圖,如圖411所示。其梯形圖如圖49所示。停車制動之前,應先產生停車制動信號,然后由停車制動信號控制接觸器實現(xiàn)停車制動。而停車信號的消除是停車時間到,T450為停層時間定時器。當存在觸發(fā)信號電梯又運行到當層時產生停車信號。其梯形圖如圖48所示。 圖47 起動加速和穩(wěn)定運行環(huán)梯形圖上述梯形圖只考慮接觸器的通電,而未考慮其斷電與互鎖等問題。 起動、穩(wěn)速運行、制動加速環(huán)節(jié) 自動運行時起動、加速和穩(wěn)定運行環(huán)節(jié)電梯起動的條件是:運行方向已確定,門已關好。為解決這一問題,引入M143M146,使上行與下行繼電器接通時間延長至上行及下行的全過程。 圖46 定向環(huán)