建筑鋼筋切斷機(jī)設(shè)計

喜歡這套資料就充值下載吧。。。資源目錄里展示的都可在線預(yù)覽哦。。。下載后都有，，請放心下載，，文件全都包含在內(nèi)，圖紙為CAD格式可編輯，【有疑問咨詢QQ:414951605 或 1304139763】 徐州工程學(xué)院 畢業(yè)設(shè)計（論文）任務(wù)書 機(jī)電工程 學(xué)院 機(jī)械設(shè)計制造及其自動化 專業(yè) 設(shè)計（論文）題目 建筑鋼筋切斷機(jī) Reinforcing steel cutting machine 學(xué) 生 姓 名 胡方超 班 級 04機(jī)本（2） 起 止 日 期 08.2.25至08.6.2 指 導(dǎo) 教 師 徐忠武 教研室主任 李志 發(fā)任務(wù)書日期 08年 2月 25日 1.畢業(yè)設(shè)計的背景： 隨著我國經(jīng)濟(jì)發(fā)展，一些中小型企業(yè)需求大量的機(jī)械專業(yè)從事生產(chǎn)第一線 的技術(shù)和管理人員，我校是培養(yǎng)應(yīng)用型人才的學(xué)校，其中大多數(shù)的課題應(yīng) 與生產(chǎn)實際相聯(lián)系。該課題是一種中等深度的常見機(jī)械，通過設(shè)計可以使 學(xué)生學(xué)習(xí)機(jī)械設(shè)計的一般方法。培養(yǎng)綜合運用所學(xué)知識，解決生產(chǎn)實際問 題的能力為以后從事生產(chǎn)實際工作打下一定基礎(chǔ)。通過畢業(yè)設(shè)計，可以讓 學(xué)生全面系統(tǒng)回顧所學(xué)知識。 2.畢業(yè)設(shè)計(論文)的內(nèi)容和要求： 1完成總體及傳動部分的設(shè)計 2設(shè)計圖紙不少于A0 3.5張 3設(shè)計說明書不少于20000字 4譯文不少于5000字 5最大鋼筋直徑D=40mm 6每分鐘切斷次數(shù)32次 3.主要參考文獻(xiàn)： 袖珍機(jī)械設(shè)計師手冊第二版 簡明實用建筑工程手冊 中國機(jī)械設(shè)計大典 機(jī)械原理 4.畢業(yè)設(shè)計(論文)進(jìn)度計劃(以周為單位)： 起 止 日 期 工 作 內(nèi) 容 備 注 周次 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 設(shè)計內(nèi)容及要求 理解設(shè)計任務(wù)，搜集相關(guān)資料 調(diào)研鋼筋切斷機(jī)的有關(guān)資料 制定總體方案 完成傳動部分的設(shè)計計算 完成裝配圖 完成裝配圖 完成裝配圖 繪制零件圖 繪制零件圖 繪制相關(guān)部件總成 繪制相關(guān)部件總成 外文翻譯 編寫設(shè)計說明書 完善設(shè)計圖及說明書 完善設(shè)計圖及說明書 教 研室審查意見： 室主任 年 月 日 學(xué)院審查意見： 教學(xué)院長 年 月 日 徐州工程學(xué)院 畢業(yè)設(shè)計（論文）開題報告 課 題 名 稱： 鋼筋切斷機(jī)的設(shè)計 學(xué) 生 姓 名：胡方超 學(xué)號：20040601237 指 導(dǎo) 教 師： 徐忠武 職稱： 副教授 所 在 學(xué) 院： 機(jī)電工程學(xué)院 專 業(yè) 名 稱： 機(jī)械設(shè)計制造及自動化 徐州工程學(xué)院 2008年3月 4日 說 明 1．根據(jù)《徐州工程學(xué)院畢業(yè)設(shè)計(論文)管理規(guī)定》，學(xué)生必須撰寫《畢業(yè)設(shè)計（論文）開題報告》，由指導(dǎo)教師簽署意見、教研室審查，學(xué)院教學(xué)院長批準(zhǔn)后實施。 2．開題報告是畢業(yè)設(shè)計（論文）答辯委員會對學(xué)生答辯資格審查的依據(jù)材料之一。學(xué)生應(yīng)當(dāng)在畢業(yè)設(shè)計（論文）工作前期內(nèi)完成，開題報告不合格者不得參加答辯。 3．畢業(yè)設(shè)計開題報告各項內(nèi)容要實事求是，逐條認(rèn)真填寫。其中的文字表達(dá)要明確、嚴(yán)謹(jǐn)，語言通順，外來語要同時用原文和中文表達(dá)。第一次出現(xiàn)縮寫詞，須注出全稱。 4．本報告中，由學(xué)生本人撰寫的對課題和研究工作的分析及描述，沒有經(jīng)過整理歸納，缺乏個人見解僅僅從網(wǎng)上下載材料拼湊而成的開題報告按不合格論。 5. 課題類型填：工程設(shè)計類；理論研究類；應(yīng)用（實驗）研究類；軟件設(shè)計類；其它。 6、課題來源填：教師科研；社會生產(chǎn)實踐；教學(xué)；其它 課題 名稱 建筑鋼筋切斷機(jī) 課題來源 社會生產(chǎn)實踐 課題類型 工程設(shè)計類 選題的背景及意義 目前，我國建筑業(yè)施工現(xiàn)場及專業(yè)鋼筋加工車間，越來越需要一種體積小，重量輕，方便，節(jié)能的小型鋼筋切斷機(jī)，至今尚未研制理想的這種鋼筋切斷機(jī)型。使用中的小型鋼筋切斷機(jī)，大多數(shù)是大型的相似縮小，但體積和功率所降無幾。對此，本設(shè)計對此需要作了調(diào)研和改進(jìn)。通過設(shè)計對知識有全面的應(yīng)用。 研究內(nèi)容擬解決的主要問題 （1）全封閉結(jié)構(gòu)鋼筋切斷機(jī)均采用減速箱結(jié)構(gòu)用螺栓連接，不僅剛性差而且還增加了結(jié)合面的加工，和蓋后常常從該處漏油；而整體式結(jié)構(gòu)鋼筋切斷機(jī)活動刀處均采用側(cè)開蓋結(jié)構(gòu)，由于切斷機(jī)工作時所受側(cè)向力很大，故側(cè)蓋常常損壞。（20采用曲柄連桿機(jī)構(gòu)并用〈3KW電機(jī)驅(qū)動的同類產(chǎn)品，其工作主軸偏心均小，這樣在切剪公稱直徑范圍不同直徑的鋼筋時就需要更換刀片或刀片加墊片才能完成或剪切鋼筋的要求，因此每臺鋼筋切斷機(jī)都要儲備幾種不同的刀片或刀墊，以備調(diào)整使用，這樣就給使用和保管帶來麻煩，同時也增加了機(jī)器的成本。而不需更換刀片或刀墊的同類型切斷機(jī)其驅(qū)動功率均〉3KW，這樣不僅使切斷機(jī)的能耗加大，而且增加了體積和重量。（3）國內(nèi)切斷機(jī)刀片側(cè)隙的調(diào)整是靠選配尺寸固定的刀墊或在刀片的后面加減刀片來實現(xiàn)的，這種調(diào)整的方法不僅麻煩，勞動強度大，工作效率低，而且還不能保證間隙的合理，常常由于間隙過大，使有效剪切力減小，剪切能力下降，同時還使機(jī)體所受側(cè)向力加大，造成機(jī)體斷裂，直接影響切斷機(jī)的使用壽命。（4）減速箱結(jié)構(gòu)全封閉鋼筋切斷機(jī)操作位置低，不符合人機(jī)功能設(shè)計要求，操作費力，且穩(wěn)定性較差 研究方法技術(shù)路線 調(diào)研，查閱資料，制定總體規(guī)劃。參照現(xiàn)有的產(chǎn)品，在此基礎(chǔ)上做一些改進(jìn)，對存在的問題的做了一些解決。利用所學(xué)知識在選擇的材料上有所改變。滿足性能的基礎(chǔ)上，降低價格。 研究的總體安排和進(jìn)度計劃 周次 設(shè)計內(nèi)容及要求 1 理解設(shè)計任務(wù)，搜集相關(guān)資料 2 調(diào)研鋼筋切斷機(jī)的有關(guān)資料 3 制定總體方案 4 完成傳動部分的設(shè)計計算 5 完成裝配圖 6 完成裝配圖 7 完成裝配圖 8 繪制零件圖 9 繪制零件圖 10 繪制相關(guān)部件總成 11 繪制相關(guān)部件總成 12 外文翻譯 13 編寫設(shè)計說明書 14 完善設(shè)計圖及說明書 15 完善設(shè)計圖及說明書 16 裝訂說明書，準(zhǔn)備答辯 主要參考 文獻(xiàn) [1] 毛謙德，李振清。袖珍機(jī)械設(shè)計師手冊第二版，機(jī)械工業(yè)出版社 [2] 范思沖，機(jī)械制圖，機(jī)械工業(yè)出版社。 [3] 邱宣懷，機(jī)械設(shè)計，高等教育出版社 [4] 羅洪田，機(jī)械原理課程設(shè)計指導(dǎo)書，高等教育出版社 [5] 龔桂義，機(jī)械設(shè)計課程設(shè)計指導(dǎo)書，高等教育出版社 [6] 馬越， 簡明實用建筑工程手冊 [7] 王啟義， 中國機(jī)械設(shè)計大典， 江西科學(xué)技術(shù)出版社 [8] 單麗云 張亞非，工程材料，中國礦業(yè)大學(xué)出版社 [9]劉鴻文， 材料力學(xué)， 高等教育出版社 [10]何德榮，曲柄壓力機(jī)， 北京機(jī)械工業(yè)出版社 [11]國家標(biāo)準(zhǔn)局，GB85522-87鋼筋切斷機(jī)試驗方法 [12]陳維新， 材料力學(xué)，人民教育出版社 指導(dǎo)教師 意 見 指導(dǎo)教師簽名： 年 月 日 教研室意見 學(xué)院意見 教研室主任簽名： 年 月 日 教學(xué)院長簽名： 年 月 日 徐州工程學(xué)院畢業(yè)設(shè)計(論文) 摘要 鋼筋切斷機(jī)是把鋼筋切成所需長度的專用機(jī)械在大型建筑工地上的應(yīng)用非常廣泛。鋼筋切斷機(jī)分為機(jī)械傳動和液壓傳動兩種。機(jī)械傳動式鋼筋切斷機(jī),工作時大都采用電動機(jī)經(jīng)一級三角帶傳動和二級齒輪傳動減速后,帶動曲軸旋轉(zhuǎn),曲軸推動連桿使滑塊和動刀片在機(jī)座的滑道中作往復(fù)直線運動,使活動刀片和固定刀片相錯而切斷鋼筋。 GQ40B型鋼筋切斷機(jī)，其剪切運動是由一曲型的曲軸連桿機(jī)構(gòu)完成的。但是由于切斷機(jī)機(jī)體內(nèi)腔狹小，在裝配曲軸連桿時比較困難。尤其是在使用中發(fā)生故障需要維修時，拆卸曲軸連桿更加不容易，給維修造成很大的不變，因此在不改變設(shè)備功能的情況下，我對曲軸連桿機(jī)構(gòu)做了一些改進(jìn)。 改進(jìn)后的凸輪結(jié)構(gòu)直接從機(jī)體航的注冊孔中裝入和取出。而不必拆卸連桿，大大簡化了裝配程序，減輕的工人的勞動強度。同時也極大的方便了維修，還簡化了零件的工藝過程，取得良好的經(jīng)濟(jì)效益。 關(guān)鍵詞　鋼筋切斷機(jī)；凸輪；曲軸連桿機(jī)構(gòu) Abstract Reinforcing steel cutting machine is to cut the required length of steel machinery specialized for large construction sites in the application of very extensive. Reinforcing steel cutting machine into mechanical transmission and hydraulic transmission of two. Mechanical transmission reinforced cutting machine, working mostly used as a V-belt drive motor and gear drive slow down after two, driven crankshaft rotation, promoting the crankshaft and connecting rod to move the slider blade in the frame of the chute in a reciprocating linear motion So that the activities of the blade and a fixed blade and cut off the wrong steel. GQ40B-steel cutter, cut its movement from one type of linkage to complete the crankshaft. However, due to cut off the small inner cavity of the body, in the assembly when the crankshaft link more difficult. Especially in the use of a fault in need of repair, demolition crank link more difficult to repair a big change, so do not change the function of the equipment under the circumstances, we crank linkage has made some improvement. The improved structure of the cam directly from the body of the aircraft registered in the hole and packed out. Without dismantling the link, greatly simplifies the assembly, reduce labor intensity of workers. But also greatly facilitate the maintenance, has also simplified the process of parts and achieved good economic returns. Keywords Reinforcing steel cutting machine Cam Crankshaft Linkage 目錄 1緒論 1 1.1鋼筋切斷機(jī)的作用 1 1.2鋼筋切斷機(jī)的機(jī)理 1 1.2.1壓入變形階段 1 1.2.2剪切滑移階段 2 1.2.3剪切滑移階段作用力分析 3 1.2.4剪切全過程剪力分析 4 1.2.5綜合分析 4 1.3鋼筋切斷機(jī)理分析 7 1.3.1目前鋼筋切斷機(jī)存在的問題 9 1.3.2鋼筋切斷機(jī)前景 10 2電動機(jī)的選擇 11 2.1計算剪切力P 11 2.2切斷機(jī)匹配電動機(jī)功率理論計算 11 3減速器的設(shè)計 13 3.1傳動比的計算與分配 13 3.2計算傳動裝置的運動和動力參數(shù) 13 3.3帶的選擇 14 3.3.1帶的計算 14 3.3.2帶的根數(shù)確定 15 3.4齒輪的設(shè)計及模數(shù)的選擇 15 3.4.1第一級齒輪傳動設(shè)計 15 3.4.2第二級齒輪傳動設(shè)計方法同第一級設(shè)計 17 3.5軸徑的選擇以及軸承的選擇 19 3.5.1軸徑的計算 19 3.5.2軸的校核 20 3.6滾動軸承的選擇計算 23 3.7標(biāo)準(zhǔn)件 24 4連桿的設(shè)計 25 5提高強度的幾種方法 27 5.1機(jī)體強度提高的設(shè)計 27 5.2改變壓刀結(jié)構(gòu) 28 5.3其他部件的改進(jìn)設(shè)計 28 6鋼筋切斷機(jī)強度計算參考 30 6.1機(jī)體額口的強度計算 30 6.2應(yīng)力計算 31 6.2.1正應(yīng)力計算 31 6.2.2計算剪切力P 31 6.3計算剪切力P 32 6.3.1計算正應(yīng)力 32 6.3.2計算最大應(yīng)力 32 6.3.3試棒 32 6.4測試方法 32 6.4.1剪切力的測量 32 6.4.2應(yīng)力測量 33 6.4.3測試結(jié)果和理論計算分析情況對比分析 33 7機(jī)械式鋼筋切斷機(jī)調(diào)整及保養(yǎng)的使用 35 7.1鋼筋切斷機(jī)的使用調(diào)整 35 7.2保養(yǎng) 37 7.3安全一般規(guī)定 37 結(jié)論 38 致謝 39 參考文獻(xiàn) 40 附錄 41 附錄1 41 附錄2 46 4 徐州工程學(xué)院畢業(yè)設(shè)計(論文) 附錄 附錄1 Basic Machining Operations and Machine Tools Basic Machining Operations Machine tools have evolved from the early foot-powered lathes of the Egyptians and John Wilkinson’s boring mill. They are designed to provide rigid support for both the workpiece and the cutting tool and can precisely control their relative positions and the velocity of the tool with respect to the workpiece. Basically, in metal cutting, a sharpened wedge-shaped tool removes a rather narrow strip of metal from the surface of a ductile workpiece in the form of a severely deformed chip. The chip is a waste product that is comsiderably shorter than the workpiece from which it came but woth a corresponding increase in thickness of the uncut chip. The geometrical shape of the machine surface depedns on the shape of the tool and its path during the machinig operation. Most machining operations produce parts of differing geometry. If a rough cylindrical workpiece revolves about a central axis and the tool penetrates beneath its surface and travels parallel to the center of rotation, a surface of revolution is producedand the operation is called turning. If a hollow tube is machined on the inside in a similar manner, the operation is called boring. Producing an external conical surface of uniformly varying diameter is called taper turning. If the tool point travels in a path of varying radius,a contoured surface like that of a bowling pin a can be produced; or, if the piece is short enough and the support is sufficiently rigid, a contoured surface could be produced by feeding a shaped tool normal to the axis of rotation. Short tapered or cylindrical surfaces could also be contour formed. Flat or plane surfaces are frequently required. The can be generated by adial turning or facing, in which the tool point moves normal to the axis of rotation. In other cases, it is more convenient to hold the workpiece steady and reciprocate the tool across it in a series of straight-line cuts with a crosswise feed increment before each cutting stroke. This operation is called planing and is carried out on a shaper. For larger pieces it is easier to keep the tool stationary and draw the workpiece under it as in planing. The tool is fed at each reciprocation. Contoured surfaces can be produced by using shaped tools. Multiple-edged tools can also be used. Drilling uses a twin-edged fluted tool for holes with depths up to 5 10times the drill diameter. Whether the dril turns or the workpiece rotates, relative motion between the cutting edge and the workpiece is the important factor. In milling operations a rotary cutter with a number of cutting edges engages the workpiecem which moves slowly with respect to the cutter. Plane or contoured surfaces may be produced, depending on the geometry of the cutter and the type of feed. Horizontal or vertical axes of rotation ma be used, and the feed of the workpiece may be in any of the three coordinate directions. Basic Machine Tools Machine tools are used to produce a part of a specified geometrical shape and precise size by removing metal from a ductile materila in the form of chips. The latter are a waste product and vary from long continuous ribbons of a ductile material such as steel, which are undesirable from a disposal point of view, to easily handled well-broken chips resulting from cast iron. Machine tools perform five basic metal-removal processes: turning, planing, drilling, milling, and frinding. All other metal-removal processes are modifications of these five basic processes. For example, boring is internal turning;reaming,tapping, and counterboring modify drilled holes and are related to drilling; hobbing and gear cutting are fundamentally milling operations; hack sawong and broaching are a form of planing and honing; lapping, superfinishing, polishing, and buffing are avariants of grinding or abrasive removal operations. Therefore, there are only four types of basic machine tools, which use cutting tools of specific controllable feometry: 1.lathes, 2.planers, 3.drilling machines, and 4.milling machines. The frinding process forms chips, but the geometry of the barasive grain is uncontrollable. The amount and rate of material removed by the various machining processes may be large, as in heavy truning operations, or extremely small, as in lapping or superfinishing operations where only the high spots of a surface are removed. A machine tool performs three major functions: 1.it rigidly supports the workpiece or its holder and the cutting tool; 2. it provedes relative motion between the workpiece and the cutting tools; 3. it provides a range of feeds and speeds usually ranging from 4 to 32 choices in each case. Speed and Feeds in Machining Speeds feeds, and depth of cut are the three major variables for economical machining. Other variables are the work and tool materials, coolant and geometry of the cutting tool. The rate of metal removal and power required for machining depend upon these variables. The depth of cut, feed, and cutting speed are machine settings that must be established in any metal-cutting operation. They all affect the forces, the power, and the rate of metal removal. They can be defined by comparing them to the needle and record of a phonograph. The cutting speed is represented by the velocity of the record surface relative to the needle in the tone arm at any instant. Feed is represented by the advance the needle radially inward per revolution, or is the difference in position between two adjacent grooves. Turning on Lathe Centers The basic operations performed on an engine lathe are illustrated in Fig. Those operations performed on extemal surfaces with a single point cutting tool are called turning. Except for drilling, reaming, and tapping, the operations on intermal surfaces are also performed by a single point cutting tool. All machining operations, including turning and boring, can be classified as roughing, finishing, or semi-finishing. The objective of a roughing ooperation is to remove the bulk of the material sa repidly and as efficiently as possible, while leaving a small amount of material on the work-piece for the finishing operation. Finishing operations are performed to btain the final size, shape, and surface finish on the workpiece. Sometimes a semi-finishing operation will precede the finishing operation to leave a small predetermined and uniform amount of stoxd on the work-piece to be removed by the finishing operation. Generally, longer workpieces are turned while supported on one or two lathe centers. Cone shaped holes, called center holes, which fit the lathe centers are drilled in the ends of the workpiece-usually along the axis of the cylindrical part. The end of the workpiece adjacent to the tailstock is always supported by a tailstock center, while the end near the headstock may be supported by a headstock cener or held in a chuck. The headstock end of the workpiece may be held in a four-jar chuck, or in a collet type chuck. This method holds the workpiece firmly and transfers the power to the workpiece smoothly; the additional support to the workpiece priovided by the chuck lessens the tendency for chatter to occur when cutting. Precise results can be obtained with this method if care is taken to hold the workpiece accurately in the chuck. Very precise results can be obtained by supporting the workpiece between two centers. A lathe dog is clamped to the workpiece; together they are driven by a driver p;ate mounted on the spindle nose. One end of the workpiece is machined; then the workpiece can be turned around in the lathe to machine the other end. The center holes in the workpiece serve as precise locating surfaces as well as bearing surfaces to carry the weight of the workpiece and to resist the xutting forces. After the workpiece has been removed from the lathe for any reason, the center holes will accurately align the workpiece back in the lathe or in another lathe,or in a cylindrical grinding machine. The workpiece must never be held at the headstock end by both a chuck and a lathe center. While at first thought this seems like a quick method of aligning the workpiece in the chuck, this must not be done because it is not possible to press evenly with the jaws against the workpiece while it is also supported by the center. The alignment provided by the center will not be maintained and the pressure of the jaws may damage the center hole, the lathe center,and prehaps even the lathe spindle. Compensatng or floating jaw chucks used almost exclusively on high production work provice an exception to the statements made above. These chucks are really work drivers and cannot be used for the same purpose as ordinary three or four=jaw chucks. While very large diameter workpieces are sometimes mounted on two centers, they are preferably held at the headstock end by faceplate jaes to obtain the smooth power transmission; moreover, large lathe dogs that are adequate to transmit the power not generally available, although they can be maed as a special. Faceplate jaws are like chuck jaws except that thet are mounted on a faceplate, which has less overhang from the spindle bearings than a large chuck would have. Boring The boring operation is generally performed in two steps; namely, rough boring and finish boring. The objective of the rough-boring operation is to remove the excess metal rapidly and efficiently, and the objective of the finish-boring operation is to obtain the desired size, surface finish, and location of the hole. The size of the hole is obtained by using the trial-cut procedure. The diameter of the hole can be measured with inside calipers and outside micrometer calipers. Basic Measuring Insteruments, or inside micrometer calipers can be used to measure the diameter directly. Cored holes and drilled holes are sometimes eccentric wwith respect to the rotation of the lathe. When the boring tool enters the work, the boring bar will take a deeper cut on one side of the hole than on the other, and will deflect more when taking this deeper cut,with the result that the bored hole will not be concentric with the rotation of the work. This effect is corrected by taking several cuts through the hole using a shallow depth of cut. Each succeeding shallow cut causes the resulting hole to be more concentric than it was with the previous cut. Before the final, finish cut is taken, the hole should be concentric with the rotation of the work in order to make certain that the finished hole will be accurately located. Shoulders, grooves, contours, tapers, and threads are bored inside of holes. Internal grooves are cut using a tool that is similar to an external grooving tool. The procedure for boring internal shoulders is very similar to the procedure for turning shoulders.large shoulders are faced with the boring tool positioned with the nose leading, and using the cross slide to feed the tool. Internal contours can be machined using a tracing attachment on a lathe. The tracing attachment is mounted on the cross slide and the stylus follows the outline of the master profile plate. This causes the cutting tool to move in a path corresponding to the profile of the master profile plate. Thus, the profile on the master profile plate is reproduced inside the bore. The master profile plate is accurately mounted on a special slide which can be precisely adjusted in two dirctions, in two directionsm, in order to align the cutting tool in the correct relationship to the work. This lathe has a cam-lick type of spindle nose which permits it to take a cut when rotating in either direction. Normal turning cuts are taken with the spindle rotating counterclockwise. Thie boring cut is taken with the spindle revolving in a clockwise direction, or “backwards”. This permits the boring cut to be taken on the “back side” of the bore which is easier to see from the operator’sposition in front of the lathe. This should not be done on lathes having a threaded spindle nose because the cutting force will tend to unscrew the chuck. 附錄2 基本的加工工序和機(jī)床 基本的加工工序 機(jī)床是從早期的埃及人的腳踏動力車床和約翰·威爾金森的鏜床發(fā)展而來。它們用于為工件和刀具兩者提供剛性支承并且可以精確控制它們的相對位置和相對速度?；旧现v，在金屬切削中一個磨尖的楔形工具以緊湊螺紋形的切屑形式從有韌性工件表面去除一條很窄的金屬。切屑是廢棄的產(chǎn)品，與其工件相比相當(dāng)短但是比未切屑的部分有相對的增加。機(jī)器表面的幾何形狀取決于刀具的形狀以及加工操作過程中刀具的路徑。 大多數(shù)加工工序生產(chǎn)出不同幾何形狀的部件。如果一個粗糙的柱形工件繞中心軸旋轉(zhuǎn)而且刀具穿破工件表面并沿與旋轉(zhuǎn)中心平行的方向前進(jìn)，就會產(chǎn)生一個旋轉(zhuǎn)面，這道工序叫車削。如果以類似的方式加工一根空心管的內(nèi)部，則這道工序就叫鏜削。制造一個直徑均勻變化的錐形外表面叫做錐體車削。如果刀具尖端以一條半徑可變的路徑前進(jìn)，就可以制造出像保齡球桿那種仿形表面；如果工件足夠短而且支承具有足夠的剛性，仿形表面可以通過進(jìn)給一個垂直于旋轉(zhuǎn)軸的仿形工具來制造。短的錐面或柱面也可以仿形切削。 常常需要的是平坦的或平的表面。它們可以通過徑向車削或端面車削來完成，其中刀具尖端沿垂直于旋轉(zhuǎn)軸的方向運動。在其他情況下，更方便的是固定工件不動，以一系列直線式切削的方式往復(fù)運動刀具橫過工件，在每次切削行程前具有一定橫向進(jìn)給量。這種龍門刨削，和牛頭刨削是在刨床上進(jìn)行的。大一些的工作很容易保持刀具固定不動，而像龍門刨削那樣在其下面拉動工件，在每次往復(fù)時進(jìn)給刀具。仿形面可以通過使用仿形刀具來制造。 也可以使用多刃刀具。鉆削使用兩刃刀具，孔深可達(dá)鉆頭直徑的5～10倍。不管是鉆頭轉(zhuǎn)動還是工件旋轉(zhuǎn)，切削刃與工件之間的相對運動是一個重要因數(shù)。在銑削作業(yè)中，有許多切削刃的旋轉(zhuǎn)銑刀與工件相接合，這種工件相對銑刀運動緩慢。根據(jù)銑刀的幾何形狀和進(jìn)給的方式，可以加工出平面和仿形面?？梢允褂盟交虼怪毙D(zhuǎn)軸，工件可以沿三個坐標(biāo)方向中的任意一個進(jìn)給。 基本的機(jī)床 機(jī)床用于以切屑的形式從韌性材料上去除金屬來加工特殊幾何形狀和精密尺寸的部件。切屑是廢品，其變化形狀從像鋼這樣的韌性材料的長的連續(xù)帶狀屑到鑄鐵形成的易于處理、徹底斷掉的切屑，從處理的觀點來講，不想要長的連續(xù)帶狀屑。機(jī)床完成5種基本的金屬切削工藝：車削、刨削、鉆削、銑削和磨削。其它所有金屬切削工藝都是這5種基本工藝的變形。例如：鏜削是內(nèi)部的車削；鉸削、錐體車削和平底锪孔則修改鉆孔，與鉆削有關(guān)；滾齒與切齒是基本銑削作業(yè)；弓鋸削和拉削是刨削和珩磨的一種形式；而研磨、超精加工、拋光和磨光則是磨削和研磨切屑作業(yè)的各種變化形式。因此，僅有4種使用專用可控幾何形狀的刀具的基本機(jī)床：1.車床2.刨床3.鉆床4.銑床。磨削工藝形成碎屑，但是磨粒的幾何形狀不可控制。 不同的加工工藝切屑的材料的量和速度可能大，如大型車削作業(yè)；或者極小，如研磨或超精加工作業(yè)，只有表面高出的點被去除。 機(jī)床完成3種主要功能：1.剛性支承工件或工件夾具以及切削刀具；2.提供工件與切削刀具之間的相對運動；3.提供了一定范圍的速度和進(jìn)給，通常每種情況有4～32種選擇。 加工中的速度和進(jìn)給 切割速度、進(jìn)給和深度是經(jīng)濟(jì)加工的3個主要變量，其它變量還有工件和工具的材料、冷卻劑以及切削刀具的幾何形狀。金屬切削的速率和加工所需的功率就取決于這些變量。 切割深度、進(jìn)給和切削速率是在任何金屬切削作業(yè)中必須都建立的機(jī)器設(shè)置。它們都影響切削力、功率和對金屬切削的速率?？梢酝ㄟ^把它們與留聲機(jī)的唱針和唱片相比較給出其定義。切削速度由任意時刻唱片表面相對于拾音器支臂內(nèi)部的速度來表示；進(jìn)給由唱針每圈徑向向內(nèi)的前進(jìn)量或者由兩個相鄰槽的位置差來表示。切削的深度是唱針進(jìn)入唱片的量或者是槽的深度。 切削 在普通車床上完成的基本車削工序，那些在外表面上用單刃刀具完成的工序叫車削。除鉆削、鉸削和錐體車削外，在內(nèi)表面的作業(yè)也由單刃刀具完成。 包括車削和鏜削在內(nèi)的所有加工工序都可以分為粗加工、精加工和半精加工。粗加工工序的目的是盡可能迅速且高效地去除大量的材料，在工件上只留下少量的材料給精加工工序。精加工工序用以獲得工件最終的大小、形狀和表面光潔度。有時，在精加工工序前進(jìn)行半精加工作業(yè)以便在工件上留下少的、預(yù)定期和均勻量的原材料供精加工去除。 通常，較長的工件是在一個或兩個車床頂尖的支承下進(jìn)行車削的。用于安裝車床頂尖的錐形孔叫作頂尖孔，它是在工件的端部鉆出的—通常沿著柱形部件的軸心。與尾架鄰近的工件端部總是由尾架頂尖支承，而挨著主軸箱的一端則由主軸箱頂尖支承或裝在卡盤內(nèi)。工件的主軸箱一端可以裝在一個四爪卡盤內(nèi)。這種方法牢固地夾持工件并且把功率平穩(wěn)地傳送到工件；由卡盤提供的額外支承減少了車削作業(yè)時發(fā)生震動的傾向。如果仔細(xì)地將工件精確固定在卡盤上，用這種方法將可以獲得精密的結(jié)果。 通過將工件支承在兩個頂尖之間可以獲得非常精密的結(jié)果。一個車床夾頭夾在工件上；然后由安裝在主軸前端的撥盤一起帶動。先加工工件的一端，然后可以在車床上將工件轉(zhuǎn)過來加工另一端。工件上的頂尖孔是用作精確定位面以及承受工件重量和抵抗車削力的軸承面。在工件由于任何原因被從車床上拆下后，頂尖孔可以精確地將工件裝回車床或另一臺車床，或都裝在一臺外圓磨床上。工件永遠(yuǎn)也不要同時通過卡盤和車床頂尖安裝在主軸箱端。雖然乍一想這似乎是一種在卡盤中對正工件的快捷辦法，但是一定不能這么做，因為當(dāng)工件同時同頂尖支承時不可能將工件均勻地壓在爪上。由頂尖獲得的對正不能維持而且爪的壓力可能損壞頂尖孔、車床頂尖甚至車床主軸。幾乎被獨自用在大量生產(chǎn)工件上的補償或浮動爪式卡盤是上述的一個例外。這些卡盤是自動偏心夾緊卡盤不能起到普通三爪或四爪卡盤同樣的作用。 直徑非常大的工件雖然有時安裝在兩個頂尖上，但是最好用花盤爪把它們固定在主軸箱端以獲得流暢的動力傳輸；此外，可以把它們制造成專用部件，但是一般沒有提供足夠大的車床夾頭來傳輸動力。除了是安裝在花盤上以外，花盤爪像卡盤爪，其主軸軸承上的外伸要比大卡盤上的也要少一些。 鏜削 鏜削工序一般分兩步完成，即粗鏜和精鏜。粗鏜工序的目的是快速，高效地去除多余的金屬；而精鏜工序的目的是獲得所需的尺寸、表面光潔度和孔的位置?？椎某叽缤ㄟ^使用試切割程序而獲得?？椎闹睆娇梢杂脙?nèi)卡尺和外千分卡尺測量。測量儀表或內(nèi)千分卡尺可用于直接測量直徑。 型心孔和鉆的孔有時相對于車床的旋轉(zhuǎn)是偏心的。當(dāng)鏜孔工具進(jìn)入工件時，鏜桿在孔的一邊的切口比另一邊深，當(dāng)采用這一深切口時就會更偏斜了，結(jié)果鏜的孔不與工件旋轉(zhuǎn)同心。這一影響通過利用淺切口在整個孔加工中進(jìn)行幾次線切口來糾正。因為每個淺切口使形成的孔比使用先前切口形成的孔更加同心。在完工前，進(jìn)行精加工，孔應(yīng)該與工件的旋轉(zhuǎn)同心以確保完工孔會精確定位。 肩、溝槽、輪廓、錐度和螺紋也應(yīng)該在孔內(nèi)鏜出。內(nèi)槽是用與外部開槽工具相擬的工具切削。鏜削內(nèi)槽的步驟非常類似于肩部的步驟。大的肩部使用前導(dǎo)裝置定位的鏜孔工具進(jìn)行刮削，使用橫向滑板進(jìn)給刀具。內(nèi)部輪廓使用車床上的描摹附件加工。仿形板附件安裝在橫向滑板上，靠模指跟隨標(biāo)準(zhǔn)剖面樣板的輪廓線運動。這使刀具對應(yīng)于標(biāo)準(zhǔn)剖面樣板的輪廓線的路徑進(jìn)行移動。這樣標(biāo)準(zhǔn)剖面樣板的輪廓就在孔內(nèi)得到復(fù)制。標(biāo)準(zhǔn)剖面樣板精確安裝在一個專用的滑板上，滑板可以在兩個方向上進(jìn)行精確調(diào)整以使刀具與工件以正確的關(guān)系對正。這臺車床有一個偏心夾型的主軸前端，允許在任意一方向旋轉(zhuǎn)時進(jìn)行切削。正常的車削世削是在主軸逆時針轉(zhuǎn)動時進(jìn)行的；鏜削切削是在主軸順時針方向或“向后”轉(zhuǎn)動時進(jìn)行的。這允許在孔的“后側(cè)”進(jìn)行鏜削切削，在車床前面，從操作者的位置易于看到 孔。在具有螺紋主軸前端的車床上不應(yīng)這么做，因為切削力會旋松卡盤。 8