1、 PAGE62 / NUMPAGES71 畢業(yè)設(shè)計(jì)任務(wù)書(shū)專(zhuān)業(yè) 機(jī)械設(shè)計(jì)制造與其自動(dòng)化 班級(jí) 091 下發(fā)日期 2013-03-01題目基于三維設(shè)計(jì)的系列專(zhuān)用夾具設(shè)計(jì)專(zhuān)題機(jī)床夾具設(shè)計(jì)主要容與要求本設(shè)計(jì)的目的：加工工藝的水平，從某種程度上來(lái)說(shuō)決定制造的水平，它是提高產(chǎn)品質(zhì)量的重要保證。因此，零件的加工工藝設(shè)計(jì)和工藝裝備的設(shè)計(jì)又是制造過(guò)程的重要組成部分。重點(diǎn)需要解決的問(wèn)題是進(jìn)行高水平的工藝設(shè)計(jì)，設(shè)計(jì)出定位精度高、加緊可靠而又方便制造的夾具。要求：設(shè)計(jì)出車(chē)床、銑床等至少兩種夾具。主要技術(shù)參數(shù)主要數(shù)據(jù)為：零件圖或工序圖上的技術(shù)要求；零件的生產(chǎn)綱領(lǐng)中批量生產(chǎn)。進(jìn)度與完成日期4月1日4月15日 翻譯外文資料

2、，搜集相關(guān)設(shè)計(jì)資料。4月16日5月8日 認(rèn)真分析加工零件的結(jié)構(gòu)特點(diǎn)，分析主要加工表面的表面精度、尺寸精度和其他面的相互位置精度，定出該零件的設(shè)計(jì)夾具的工序。5月9日5月26日 設(shè)計(jì)并繪制出機(jī)床夾具裝配圖。5日27日6月02日 設(shè)計(jì)并繪制夾具零件圖。6日03日6月15日 整理設(shè)計(jì)結(jié)果，撰寫(xiě)設(shè)計(jì)說(shuō)明書(shū)（注：設(shè)計(jì)說(shuō)明書(shū)的大部分是穿插在上述容中進(jìn)行的）。系主任簽字日期教研室主任簽字日期指導(dǎo)教師簽字日期指 導(dǎo) 教 師 評(píng) 語(yǔ) 指導(dǎo)教師: 年 月 日畢業(yè)設(shè)計(jì)評(píng)閱意見(jiàn)表設(shè)計(jì)題目 機(jī)床專(zhuān)用夾具設(shè)計(jì)評(píng)價(jià)項(xiàng)目評(píng)價(jià)標(biāo)準(zhǔn)（A級(jí)）滿分評(píng) 分ABCDE文獻(xiàn)資料利用能力能獨(dú)立地利用多種方式查閱中外文獻(xiàn)；能正確翻譯外文資料；

3、能正確有效地利用各種規(guī)、設(shè)計(jì)手冊(cè)等。10109876綜合運(yùn)用能力研究方案設(shè)計(jì)合理；設(shè)計(jì)方法科學(xué)；技術(shù)線路先進(jìn)可行；理論分析和計(jì)算正確；動(dòng)手能力強(qiáng)；能獨(dú)立完成設(shè)計(jì)；能綜合運(yùn)用所學(xué)知識(shí)發(fā)現(xiàn)和解決實(shí)際問(wèn)題；研究結(jié)果客觀真實(shí)。20192017181516131412設(shè)計(jì)質(zhì)量設(shè)計(jì)結(jié)構(gòu)嚴(yán)謹(jǐn)；邏輯性強(qiáng)；語(yǔ)言文字表準(zhǔn)確流暢；格式、圖、表規(guī)；有一定的學(xué)術(shù)水平或?qū)嶋H價(jià)值4037-4032-3628-3125-2724創(chuàng)新能力有較強(qiáng)的創(chuàng)新意識(shí)；所做工作有較大突破；設(shè)計(jì)有獨(dú)到見(jiàn)解151513-1411-12109工作量工作量飽滿；圓滿完成了任務(wù)書(shū)所規(guī)定的各項(xiàng)任務(wù)。151513-1411-12109總分是否同意將該設(shè)計(jì)

4、提交答辯：是（ ） 否（ )具體評(píng)閱與修改意見(jiàn)： 評(píng)閱人： 年 月 日注：1.請(qǐng)按照A級(jí)標(biāo)準(zhǔn)，評(píng)出設(shè)計(jì)各項(xiàng)目的具體得分，并填寫(xiě)在相應(yīng)項(xiàng)目的評(píng)分欄中； 2.計(jì)算出總分。若總分60分，“設(shè)計(jì)質(zhì)量”1009.31N。故本夾具可安全工作。5.3.4 定位誤差分析銑削力與夾緊力計(jì)算定位孔與定位心軸的配合尺寸取為25f6（在夾具上標(biāo)出定位心軸配合尺寸25f6）。對(duì)于工序尺寸11mm而言，定位基準(zhǔn)與工序基準(zhǔn)重合，基準(zhǔn)不重合誤差為=0，基準(zhǔn)位移誤差為=0.027mm，所以定位誤差=+=0.027mm， 而加工尺寸16mm的公差為：=0.12mm，所以，=0.027/3=0.04,因此定位方案合理。5.3.5

5、定向鍵與對(duì)刀裝置設(shè)計(jì)1、定位鍵：定向鍵是夾具與機(jī)床的聯(lián)接元件，用來(lái)確定夾具與機(jī)床工作臺(tái)之間正確位置。定位鍵一般使用兩個(gè)（其距離應(yīng)盡可能布置得遠(yuǎn)些），分辨用螺釘緊固在夾具體底面的同一直線位置的鍵槽中，其下半部分的兩側(cè)面與銑床工作臺(tái)T形槽的配合，使夾具上定位元件的工作表面對(duì)于工作臺(tái)的送進(jìn)方向具有正確的位置。定向鍵可承受銑削時(shí)產(chǎn)生的扭轉(zhuǎn)力矩，可減輕夾緊夾具的螺栓的負(fù)荷，加強(qiáng)夾具在加工中的穩(wěn)固性。根據(jù)參考文獻(xiàn)2表6.4-280161999定向鍵結(jié)構(gòu)如圖：圖5.3 定向鍵(80161999)與其與機(jī)床連接示意圖根據(jù)T形槽的寬度a=14mm定向鍵的結(jié)構(gòu)尺寸如表表5-1 定向鍵尺寸BLHhD1夾具體槽尺寸h

6、螺釘GB65-2000公稱(chēng)尺寸極限偏差h6極限偏差h8410公稱(chēng)尺寸極限偏差H7140-0.0110-0.0272085.71014+0.013M5*122、對(duì)刀裝置：對(duì)刀裝置由對(duì)刀塊和塞尺組成，其中對(duì)刀塊用來(lái)確定刀具與夾具的相對(duì)位置。對(duì)刀必須通過(guò)塞尺來(lái)確定刀具的位置，以免劃傷對(duì)刀塊的工作表面。對(duì)刀塊為單獨(dú)的元件，用銷(xiāo)釘和螺釘裝夾在夾具體便于操作的位置上。常見(jiàn)的標(biāo)準(zhǔn)對(duì)刀塊有：圓形對(duì)刀塊，用于加工單一平面時(shí)對(duì)刀；方型對(duì)刀塊：用于調(diào)整組合銑刀位置時(shí)對(duì)刀；直角對(duì)刀塊：用于加工兩相互垂直面或銑槽時(shí)對(duì)刀；側(cè)裝對(duì)刀塊：它安裝在夾具體側(cè)面，用于加工兩相互垂直面或銑槽時(shí)對(duì)刀。常用的塞尺有：15mm的平塞尺和工

7、作直徑為3mm和5mm的圓柱塞尺兩類(lèi)。其公差均按h8制造。對(duì)刀時(shí)，銑刀不能與對(duì)刀塊的工作表面直接接觸，以免損壞切削刃或造成對(duì)刀塊過(guò)早磨損，而應(yīng)通過(guò)塞尺來(lái)校準(zhǔn)它們之間的相對(duì)位置，即將塞尺放在刀具與對(duì)刀塊工作表面之間。采用直角對(duì)刀塊與平塞尺對(duì)刀。確定對(duì)刀塊的對(duì)刀面與定位元件定位表面之間的尺寸，水平方向尺寸為16/2(槽寬一般尺寸)+3（塞尺厚度尺寸）=11mm,其公差取工件相應(yīng)尺寸公差的1/3。槽寬尺寸為16mm，則水平尺寸公差?。?/3X0.12）mm=0.04mm，對(duì)稱(chēng)標(biāo)注為（110.02）mm，同理確定垂直方向尺寸為8（槽底尺寸）-3（塞尺厚度尺寸）=5mm,槽底長(zhǎng)度為自由尺寸，查公差表IT

8、11級(jí)公差值為0.09mm，則水平尺寸公差?。?/3X0.09）mm=0.03mm，確定垂直方向尺寸為（50.03）mm。由于本工序是完成此撥叉的槽粗、精銑加工，所以選用直角對(duì)刀塊。根據(jù)/T8044-1999直角對(duì)刀塊的結(jié)構(gòu)和尺寸如圖。塞尺選用平塞尺，其結(jié)構(gòu)如圖所示表5-2 塞尺尺寸公稱(chēng)尺寸H允差dC3-0.0060.25夾具上所裝的對(duì)刀塊，可使夾具在一批零件的加工前很好地對(duì)刀（與塞尺配合使用）；同時(shí)，夾具體底面上的一對(duì)定位鍵可使整個(gè)夾具在機(jī)床工作臺(tái)上有一個(gè)正確的安裝位置，有利于銑削加工。參考文獻(xiàn)2選用直角對(duì)刀塊，其結(jié)構(gòu)尺寸如圖所示：圖5.4直角對(duì)刀塊(GB224180 A型)塞尺選用平塞尺，

9、其結(jié)構(gòu)如圖所示：圖5.5平塞尺(/T8032.1-1999)3、夾具體的設(shè)計(jì)：由于銑削時(shí)的切削力較大，因此，銑床夾具的夾具體不僅要有足夠的剛度和強(qiáng)度，其高度和寬度之比也應(yīng)恰當(dāng)，一般為H/B11.25以降低夾具的重心，使工件的加工表面盡量靠近工作臺(tái)面，提高加工時(shí)夾具的穩(wěn)定性。5.3.6 繪制夾具總裝圖用點(diǎn)化線劃出工件的輪廓和主要表面，主要表面是指定位基準(zhǔn)面。夾緊表面和被加工表面總裝配圖上所繪制的工件視為假想的透明體，因此不影響其他元件的繪制。然后按定位元件、對(duì)刀引導(dǎo)元件、夾緊機(jī)構(gòu)傳動(dòng)裝置為順序畫(huà)出各圖的具體結(jié)構(gòu)，最后畫(huà)夾緊件。圖5.6 連接螺栓圖5.7 定位長(zhǎng)圓柱銷(xiāo)圖5.8 壓緊螺母圖5.9 連

10、接螺栓圖5.10 菱形銷(xiāo)螺栓圖5.11 菱形銷(xiāo)5.12 定位鍵圖5.13 壓塊機(jī)構(gòu)圖5.14 手動(dòng)螺旋壓緊機(jī)構(gòu)、圖5.15 夾具體底座圖5.16 夾具裝配圖結(jié) 論基于三維的的系列專(zhuān)用夾具畢業(yè)設(shè)計(jì)即將結(jié)束?；仡櫿麄€(gè)過(guò)程，經(jīng)過(guò)老師和同學(xué)的幫助，還有自己不懈的努力，終于與時(shí)定量的完成了這次畢業(yè)設(shè)計(jì)。畢業(yè)設(shè)計(jì)在機(jī)械制造與自動(dòng)化專(zhuān)業(yè)中使得理論與實(shí)踐結(jié)合，對(duì)理論知識(shí)加深了理解，同時(shí)也使我們對(duì)生產(chǎn)實(shí)習(xí)的理解和認(rèn)識(shí)得到了強(qiáng)化。本次畢業(yè)設(shè)計(jì)主要是基于三維的專(zhuān)用夾具設(shè)計(jì)。機(jī)械夾具設(shè)計(jì)的運(yùn)用了工件定位、夾緊機(jī)構(gòu)等知識(shí)。通過(guò)此次設(shè)計(jì)，使我基本掌握了零件的加工過(guò)程分析、工藝文件的編制、專(zhuān)用夾具設(shè)計(jì)的方法和步驟等。學(xué)會(huì)了

11、查相關(guān)手冊(cè)、選擇使用工藝裝備等等。本次設(shè)計(jì)還存在很多不足之處。由于對(duì)知識(shí)的掌握不夠扎實(shí)，在設(shè)計(jì)過(guò)程中不能全面地考慮問(wèn)題。仍需要進(jìn)一步研究和實(shí)踐。這次設(shè)計(jì)，讓我對(duì)基本理論的綜合運(yùn)用與正確解決實(shí)際問(wèn)題等方面得到了一次較好的訓(xùn)練。提高了思考、解決問(wèn)題，創(chuàng)新設(shè)計(jì)的能力。為以后的設(shè)計(jì)工作打下了較好基礎(chǔ)。本設(shè)計(jì)存在很多不足之處，最后懇請(qǐng)各位老師批評(píng)指正！致 通過(guò)這一階段的努力，我的畢業(yè)設(shè)計(jì)說(shuō)明書(shū)理工大學(xué)畢業(yè)設(shè)計(jì)終于完成了。在大學(xué)階段，我在學(xué)習(xí)上和思想上都受益非淺，這除了自身的努力外，與各位老師、同學(xué)和朋友的關(guān)心、支持和鼓勵(lì)是分不開(kāi)的。寫(xiě)作畢業(yè)論文是再一次系統(tǒng)學(xué)習(xí)的過(guò)程，畢業(yè)論文的完成，同樣也意味著新的學(xué)習(xí)

12、生活的開(kāi)始。在本論文的寫(xiě)作過(guò)程中，AAA老師和BBB老師傾注了大量的心血，我非常感AAA老師和BBB老師在我大學(xué)的最后學(xué)習(xí)階段畢業(yè)設(shè)計(jì)階段給予我的指導(dǎo)，從最初的定題，到資料收集，到寫(xiě)作、修改，到論文定稿，他們一遍又一遍地指出設(shè)計(jì)中的具體問(wèn)題，嚴(yán)格把關(guān)，循循善誘，他們給了我耐心的指導(dǎo)和無(wú)私的幫助。為了指導(dǎo)我的畢業(yè)論文，他們?cè)诎倜Φ墓ぷ髦邪才艜r(shí)間，他們的這種敬業(yè)奉獻(xiàn)的精神令人欽佩，在此我向AAA老師和BBB老師表示我誠(chéng)摯的意。同時(shí)，感所有任課老師和所有同學(xué)在這四年來(lái)給自己的指導(dǎo)和幫助，是他們教會(huì)了我專(zhuān)業(yè)知識(shí)，教會(huì)了我如何學(xué)習(xí)，教會(huì)了我如何做人。正是由于他們，我才能在各方面取得顯著的進(jìn)步，在此向他們

13、表示我由衷的意，并祝所有的老師培養(yǎng)出越來(lái)越多的優(yōu)秀人才，桃滿天下！參考文獻(xiàn)1 朱詩(shī)順,駱?biāo)鼐?機(jī)械課程設(shè)計(jì)簡(jiǎn)明手冊(cè).化學(xué)工業(yè)出版,20112王先奎,旦主編.機(jī)械加工工藝手冊(cè).機(jī)械工業(yè),20063 王先奎，鳳池.機(jī)械加工工藝手冊(cè)第二卷.加工技術(shù)卷.機(jī)械工業(yè),20064 葉偉昌.機(jī)械工程與自動(dòng)化簡(jiǎn)明設(shè)計(jì)手冊(cè).機(jī)械工業(yè),20015 洪.機(jī)械加工工藝手冊(cè)M .，19966 徐鴻本.機(jī)床夾具設(shè)計(jì)手冊(cè)M.科學(xué)技術(shù)，20037 朱冬梅，胥北瀾,何建英.畫(huà)法幾何與機(jī)械制圖-6版，高等教育,20088王光斗，王春福.機(jī)床夾具設(shè)計(jì)手冊(cè)M.科學(xué)技術(shù)，20009 黃繼昌，徐巧魚(yú)，海貴.實(shí)用機(jī)構(gòu)圖冊(cè).機(jī)械工業(yè)，2008

14、10 于惠力，新敏.新編實(shí)用緊固件手冊(cè).機(jī)械工業(yè)，201111 宏鈞.實(shí)用金屬切削手冊(cè)M .機(jī)械工業(yè)，200512市金屬切削技術(shù)協(xié)會(huì).金屬切削手冊(cè)M .科學(xué)技術(shù)，200213 Machine classification and pose fixture. Prenfice Hall,Inc2002. th 414M.Lv*，X.Yang.Design and manufacture of a shaving cutter with unequal depth gashes.Journal of Materials Processing Technology 129(2002)193-195.

15、附錄1 外文資料Machine classification and pose fixture1 fixture in the role of machining Workpiece clamping fixture is a kind of process equipment, it is widely used in mechanical machining of the manufacturing process, heat treatment, assembly, welding and testing processes.In the use of metal-cutting mac

16、hine tools collectively referred to as the jig fixture. N a modern production machine is an indispensable fixture of the process equipment, machining of the workpiece, the processing requirements in order to ensure. First of all to the workpiece and machine tool relative to a correct position, and t

17、his location during processing dose not change the impact of external forces. To this end, during the pre-machining, workpiece clamping must be good .There are two ways to clamp workpiece: one is directly clamping the workpiece in the machine table or on the chuck; the other is the workpiece in the

18、fixture on the fixture. The first method used when the workpiece clamping , the general design requirements have to press lines in the surface to draw the size and location , clamping ,or when the needle is zoned dial indicator to find is after the clamping. This method need special equipment, but l

19、ow efficiency, are generally used for one-piece and small batch production. Large quantities, mostly with the workpiece clamping fixture. With the merits of the workpiece clamping fixtures are as follows. Guarantee the stability of the machining accuracy of workpiece. Workpiece with clamping fixture

20、 ,the workpiece relative to the location of tool and machine tool to ensure the accuracy of the fixture from the technical level of workers , so that a number of workpiece machining accuracy of the line .To improve labor productivity. Workpiece clamping fixture can facilitate the user easily 、rapidl

21、y, and the workpiece dose not need to find is crossed, can significantly reduce the supplementary working hours, to improve labor productivity; workpiece in the fixture after the fixture to improve the rigidity of the workpiece , thus cutting the amount of increase , to improve labor productivity; c

22、an use more pieces of multi-workpiece clamping fixture , and the use of efficient clamping bodies , to further improve labor productivity.To expand the use of machine tools. Machine tools in general use a dedicated machine tool fixture can expand the scope of the process and give full play to the po

23、tential of machine tools to achieve a multi-machine use. For example, the use of a dedicated fixture can be easily Lathe processing small box to the workpiece. .Even in the lathe out of oil, a reduction of expensive dedicated machines, reducing the cost, which is particularly important for small and

24、 medium-sized factories.To improve the operators working conditions. As the pneumatic, hydraulic,electro-magnetic power source, such as the application in the fixture, on the one hand to reduce the labor intensity of workers; the other hand, it guarantees the reliability of the workpiece clamping, a

25、nd to achieve the interlocking machine, to avoid accidents, ensure the operator safety and machine tool equipment.To reduce costs. In mass production after use of fixture, from stem to increase labor productivity, lower level technical workers, as well as lower scrap and other reasons, obviously to

26、reduce the production costs.Fixture manufacturing cost-sharing in a group of workpiece, each workpiece to increase the cost is very minimal, far less than as a result of increased labor productivity and reduce costs. The greater volume of workpiece, fixture made to use has become more significant ec

27、onomic benefits. 2 Fixture Categories2.1 General characteristics of the fixture by Category According to the production in different types in the common characteristics of machine tool fixture. Fixture can be divided into general, special fixture, adjustableclamp, and automatic line of modular fixtu

28、re fixture, such as :( 1) General Fixture. Universal fixture refers to the structure; size has been standardized, and has a certain universal fixture. This type of fixture adaptable can be used to setup the scope of a certain shape and size of various parts. (2) A dedicated fixture. This type of fix

29、ture is designed for a particular part of the processing procedures and the design and manufacture. Relatively stable in the product, the production of large quantities used a variety of special fixture, access to higher productivity and machining accuracy. (3) Adjustable fixture. Adjustable fixture

30、 for general fixture and special fixture and the defects developed a new kind of fixture. Of different types and sizes of the workpiece, simply adjust or replace the fixture at the original location of the individual components and will be used to clamp components. (4) Modular Fixture. Modular fixtu

31、re is a modular fixture. Standard components of the modular with high precision and resistance to abrasion can be assembled into a variety of fixtures. Removable fixture used to clean the assembly after the new fixture left. (5) Automatic line fixture .Automatic line clamp generally divided into two

32、 categories: fixed-type fixture,which is similar to a dedicated fixture; other accompanying a fixture for the use of the workpiece in the fixture, together with the movement, and automatic workpiece along the line from a move to the next position for processing.2.2 Classification by the use of machi

33、ne tools Classification By the use of machine tools can be divided into lathe jig fixtures, milling fixtures, drilling fixtures, hang-bed fixture, jig gear machine, CNC machine tool fixture, automatic machine tool fixtures, accompanied by automatic line, and other fixtures, such as machine tools .Th

34、is is a special fixture design of the classification method used. Dedicated fixture design, the machine group, the type and the main parameters have been determined. Their difference is the cutting forming machine tool movements, so the connection fixture with the machine in different ways. Machinin

35、g accuracy of their different requirements. 2.3 Clamping fixture according to the power source Clamping fixture according to the power source can be divided into manual fixture, pneumatic fixtures, hydraulic fixtures, gas fixtures by force, electromagnetic fixture, vacuumfixtures, fixture, such as c

36、entrifugal force.3 the composition of fixture Although the structure of machine tool fixture range, but their components can be summarized as the following sections.Positioning components. Typically, when the shape of the work piece datum position established, the position will be the basic componen

37、ts of the structure identified.Clamping device. Positioning of the work piece in the fixture, the need to clamp the work piece before processing to ensure that the work piece during processing is not due to external force and undermine its position.The specific folder. Fixture and the skeleton matri

38、x, all the components through the fixture it will constitute a whole.Of the knife or the guide. Tool used to determine position relative to the correct position of components. Of the knife device common in milling fixture. Used to adjust the cutter knife block position before machining.To connectcom

39、ponents. Connected components in the machine tool fixture are to determine the correct position on the component, therefore, can double as a specific folder to connect components. Lathe fixture on the transition plate, the positioning of milling machine fixture on key components is connected.Other d

40、evices or components. According to the processing needs, some degree fixture devices were used by mode device, the whole device, and the balance of the top block and so on. There components or devices specially designed need.Journal of Materials Processing Technology 129(2002)193-195Design and manuf

41、acture of a shaving cutter with unequal depth gashesM.Lv, X.YangCollege of Mechanical Engineering, TaiyuanUniversity of Technology,Taiyuan, Shanxi 030024, PR ChinaAbstract Gear shaving is a gear finishing operation with high efficiency and high precision. When a work gear has been shaved by a shavin

42、g cutter with a true involute profile, the “mid-concave” phenomena inevitably exist around the pitch points of the work gear tooth flanks. Aiming at this problem, a new-style shaving cutter with unequal depth gashes is designed and manufactured. This paper analyses the forming of the gash on the bas

43、is of the slotting principle, and proposes a gash-designing method. Experiment has proven that the shaved gear has a better surface finish that achieves the anticipated effect.Keywords: Gearshaving; Tooth form error, Mid-concave; Unequal depth gashes Introduction Gear shaving is applied widely to ge

44、ar manufacturing in various fields for its high efficiency, high precision and low cost. Nevertheless, there are “mid-concave” phenomena around the pitch points of the work gear it has been shaved using shaving cutter with a trueinvolute profile. This problem seriously affects the tooth surface fini

45、sh and the transmission quality of gear. It is one of the difficulties that many scholars and specialists have been studying and necessitates the improvement of the gear shaving. Thus far various methods have been employed to solve the problem in production that can reduce the mid-concave error to s

46、ome degree but cannot eliminate the error thoroughly. Gear shaving is a complicated process. Under the combined action of many factors, more materials is removed from the gear tooth surface around its pitch points and the “mid-concave” problem is caused consequently 1.If the shaving cutter has no cu

47、tting edges (i.e. no gashes) at its pitch points, the work gear will not be shaved around its pitch points and then the mid-concave error can be greatly reduced. In the light of the analysis, a new concept is proposed, namely, unequal depth gashes (i.e. the depth of the gashes is not the same along

48、the cutter tooth length). In this paper the authors not only state the reason why this shaving cutter can reduce and even eliminate tooth form error, but also analyze the forming of the gash and provide the solution.Principle of slottingThe serrations in the tooth surfaces of a common shaving cutter

49、 are produced on a special slot-generating machine. The principle of slotting is follows (Fig.1). The roll gear (1) and shaving cutter (2) are mounted and fixed on the arbor. Roll gear (1) is located between the upper rack (3) and the lower rack (4) engages with them. The upper rack (3) is fixed in

50、the runner beneath the support and the runner can keep roll gear 910 from axial movement. Lower rack (4) is fixed plate that reciprocates, pushed by the crank-link framework (5). Crank-link framework (5) is driven by electromotor (7) that is shifted by a pulley and then decelerated by reducer (6). S

51、ince the upper rack (3) is fixed, the pitch circle of roll gear (1) moves back and forth with pure rolling action along the pitch line of the upper (or lower) rack. When the diameter of the cutter base circle is equal to that of roll gear pitch circle, the base circle of cutter (2) also makes the sa

52、me movement as the pitch circle of roll gear (1) in roll-generating motion. When the tips of slotting cutter (8) are adjusted to be flush with the pitch line of the upper rack (3), shaving cutter (2) is in mesh with a moving imaginary generating rack that is reproduced in space with the tips. Genera

53、ted involute surface are produced that are identical to the cutter surface, i.e. the slotted gashes are as the cutter tooth surfaces.1. Roller rear2. Shaving cutter3. Upper rack4.lower rack5.crank-link framework6.reducer7.electrotmor8.slotting cutterFig 1 Structure diagram of slotting machineForming

54、 principle of unequal depth gashesDuring the gear shaving process, the meshing of the cutter and the work gear is the meshing of crossed axes helical gears. The shaving cutter is made in the form of a high-precision helical gear that has gashes in the tooth flanks that act as the cutting edges. The

55、cutting edges perform a cutting action depending on the relative velocity over the tooth width between the cutter and the work gear. Traditional shaving methods reduce and eliminate tooth form error by correcting the cutter tooth surfaces. However, a shaving cutter with unequal depth gashes has been

56、 designed by remodeling the gashes on the basis of mechanism of mid-concave error.As far as common shaving cutter is concerned, the profile of its gash bottom is the same as that of the cutter tooth profile, even if gashes differ in shape. As to a shaving cutter tooth with unequal depth gashes, the

57、depth of the gashes varies along the tooth length, which is zero at the pitch point and gradually becomes deeper to its maximum from the pitch point to the top and root of the cutter tooth. Because there are no gashes at the pitch point, there are no cutting edges, that is, no cutting action. Theref

58、ore, the middle part of the shaved tooth profile is not shaved and is only pressed. Thus the gear tooth from error is greatly reduced (Fig.2)Fig2.Gash profile of the shaving cutter with unequal depth gashes.The serrations of the designed shaving cutter are also produced on a special slotting machine

59、. According to the slotting principle, in order to perform gash machining, the cutter gash bottom should have an involute profile. Moreover, the base circle of the cutter involute profile is concentric with that of the gash bottom profile and the diameter of the latter is equal to the diameter of th

60、e roll gear pitch circle. The design method proposed is as follows. The gash bottom is formed by two involutes that intersect at the pitch point of the cutter tooth, and the base circles of the two involutes are concentric with that of tooth involute profile. If two corresponding roll gears are prod