1、目錄 1中文摘要 2ABSTRACT 2第1章緒綸 31 1 多軸加工應(yīng) TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT31 2多軸加工的設(shè)備 TTTTTTTTTTTTTTTTTTTTTTTTTTTTT41 3多軸加工的趨勢(shì) TTTTTTTTTTTTTTTTTTTTTTTTTTTTT5第 2 章 普通鉆床改為多軸鉆床 TTTTTTTTTTTTTTTTTTTTTTTTTT62. 1生產(chǎn)任務(wù) 62 . 2普通立式鉆的選型 6第 3 章 多軸齒輪傳動(dòng)箱的設(shè)計(jì) TTTTTTTTTTTTTTTTTTTTTTTTTTT73 1 設(shè)計(jì)前的準(zhǔn)備 TTTTTTTTTTTTTTTTTTTTTTTT

2、TTTTTTT7第4章多軸箱的結(jié)構(gòu)設(shè)計(jì)與零部件圖的繪制144. 1箱蓋、箱體和中間板結(jié)構(gòu) 1442多軸箱軸的設(shè)計(jì) 1443 軸 坐 標(biāo) 計(jì) 算 TTTTTTTTTTTTTTTTTTTTTTTTTTT30第 5 章 導(dǎo)向裝置的設(shè)計(jì) TTTTTTTTTTTTTTTTTTTTTTTTT31第 6 章 接桿刀具 TTTTTTTTTTTTTTTTTTTTTTTTTTTT31外文文獻(xiàn) 31總 結(jié) TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT36鳴謝 TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT37參考文獻(xiàn) 37中文摘要本設(shè)計(jì)是關(guān)于普通鉆床改造為多軸鉆床

3、的設(shè)計(jì)。普通鉆床為單軸機(jī)床，但安裝上多軸箱就會(huì)成為 多軸的鉆床，改造成多軸鉆床后，能大大地縮短加工時(shí)間，提高生產(chǎn)效率。因此本設(shè)計(jì)的重點(diǎn)是 多軸箱的設(shè)計(jì)，設(shè)計(jì)內(nèi)容包括齒輪分布與選用、軸的設(shè)計(jì)、多軸箱的選用、導(dǎo)向裝置設(shè)計(jì)等。關(guān)鍵詞： 多軸鉆床；生產(chǎn)效率；多軸箱AbstractThe design is about reconstructing the ordinary drill to a multiple drill. The ordinary drill is a single drill. It will improve its productive efficiency, shorten

4、its processing time if assembled a multiple spindle case on. That so calls a multiple drill. Hereby, the keystone of this design paper is how to design a multiple spindle heads. The design subjects include the selection and distribution of gear wheel, the design of spindle, and the guiding equipment

5、 and selection of the multiple spindle heads, etc.Key words: multiple drill; productive efficiency; multiple spindle heads13普通鉆床該為多軸鉆床第 1 章 緒論1.1 多軸加工應(yīng)用據(jù)統(tǒng)計(jì)， 一般在車(chē)間中普通機(jī)床的平均切削時(shí)間很少超過(guò)全部工作時(shí)間的15%。其余時(shí)間是看圖、裝卸工件、調(diào)換刀具、 操作機(jī)床、測(cè)量 以及清除鐵屑等等。 使用數(shù)控機(jī)床雖然能提高 85%， 但購(gòu)置費(fèi)用大。某些情況下，即使生產(chǎn)率高，但加工相同的零件，其成本不一定比普通機(jī)床低。 故必須更多地縮短加工時(shí)間。不

6、同的加工方法有不同的特點(diǎn)，就鉆削加工而言，多軸加工是一種 通過(guò)少量投資來(lái)提高生產(chǎn)率的有效措施。1.1.1 多軸加工優(yōu)勢(shì)雖然不可調(diào)式多軸頭在自動(dòng)線中早有應(yīng)用，但只局限于大批量生產(chǎn)。即使采用可調(diào)式多軸 頭擴(kuò)大了使用范圍，仍然遠(yuǎn)不能滿(mǎn)足批量小、孔型復(fù)雜的要求。尤其隨著工業(yè)的發(fā)展，大型復(fù)雜 的多軸加工更是引人注目。 例如原子能發(fā)電站中大型冷凝器水冷壁管板有15000個(gè)“ 20孔，若以搖臂鉆床加工，單單鉆孔與锪沉頭孔就要 842.5 小時(shí)，另外還要?jiǎng)澗€工時(shí) 151.1 小時(shí)。但若以數(shù) 控八軸落地鉆床加工，鉆锪孔只要 171.6 小時(shí)，劃線也簡(jiǎn)單，只要 1.9小時(shí)。因此，利用數(shù)控控 制的二個(gè)坐標(biāo)軸，使刀具

7、正確地對(duì)準(zhǔn)加工位置，結(jié)合多軸加工不但可以擴(kuò)大加工范圍，而且在提 高精度的基礎(chǔ)上還能大大地提高工效，迅速地制造出原來(lái)不易加工的零件。有人分析大型高速柴 油機(jī) 30 種箱形與桿形零件的 2000 多個(gè)鉆孔操作中， 有 40%可以在自動(dòng)更換主軸箱機(jī)床中用二軸、 三軸或四軸多軸頭加工， 平均可減少 20%的加工時(shí)間。 1975年法國(guó)巴黎機(jī)床展覽會(huì)也反映了多軸 加工的使用愈來(lái)愈多這一趨勢(shì)。1.2 多軸加工的設(shè)備多軸加工是在一次進(jìn)給中同時(shí)加工許多孔或同時(shí)在許多相同或不同工件上各加工一個(gè)孔。 這不僅縮短切削時(shí)間，提高精度，減少裝夾或定位時(shí)間，并且在數(shù)控機(jī)床中不必計(jì)算坐標(biāo)，減少 字塊數(shù)而簡(jiǎn)化編程。它可以采用以

8、下一些設(shè)備進(jìn)行加工：立鉆或搖臂鉆上裝多軸頭、多軸鉆床、 多軸組合機(jī)床心及自動(dòng)更換主軸箱機(jī)床。甚至可以通過(guò)二個(gè)能自動(dòng)調(diào)節(jié)軸距的主軸或多軸箱，結(jié) 合數(shù)控工作臺(tái)縱橫二個(gè)方向的運(yùn)動(dòng)，加工各種圓形或橢圓形孔組的一個(gè)或幾個(gè)工序?，F(xiàn)在就這方 面的現(xiàn)狀作一簡(jiǎn)介。1.2.1 多軸頭從傳動(dòng)方式來(lái)說(shuō)主要有齒輪傳動(dòng)與萬(wàn)向聯(lián)軸節(jié)傳動(dòng)二種。這是大家所熟悉的。前者效率較 高，結(jié)構(gòu)簡(jiǎn)單， 后者易于調(diào)整軸距。 從結(jié)構(gòu)來(lái)說(shuō)有不可調(diào)式與可調(diào)式二種。 前者軸距 不能改變， 多采用齒輪傳動(dòng)，僅適用于大批量生產(chǎn)。為了擴(kuò)大其贊許適應(yīng)性，發(fā)展了可調(diào)式多軸頭，在一定 范圍內(nèi)可調(diào)整軸距。它主要裝在有萬(wàn)向 . 二種。（ 1）萬(wàn)向軸式也有二種 :

9、具有對(duì)準(zhǔn)裝置的主軸。主 軸裝在可調(diào)支架中，而可調(diào)支架能在殼體的 T 形槽中移動(dòng)，并能在對(duì)準(zhǔn)的位置以螺栓固定。 （2） 具有公差的圓柱形主軸套。主軸套固定在與式件孔型相同的模板中。前一種適用于批量小且孔組 是規(guī)則分布的工件（如孔組分布在不同直徑的圓周上） 。后一種適用于批量較大式中小批量的輪 番生產(chǎn)中，剛性較好，孔距精度亦高，但不同孔型需要不同的模板。多軸頭可以裝在立鉆式搖臂鉆床上，按鉆床本身所具有的各種功能進(jìn)行工作。這種多軸加 工方法，由于鉆孔效率、加工范圍及精度的關(guān)系，使用范圍有限。1.2.2 多軸箱也象多軸頭那樣作為標(biāo)準(zhǔn)部件生產(chǎn)。美國(guó) Secto 公司標(biāo)準(zhǔn)齒輪箱、多軸箱等設(shè)計(jì)的不可調(diào) 式多

10、軸箱。有32種規(guī)格，加工面積從 300 X 300毫米到600 X 1050毫米，工作軸達(dá) 60根，動(dòng)力 達(dá) 22.5 千瓦。 Romai 工廠生產(chǎn)的可調(diào)多軸箱調(diào)整方便， 只要先把齒輪調(diào)整到接近孔型的位置， 然 后把與它聯(lián)接的可調(diào)軸移動(dòng)到正確的位置。因此，這種結(jié)構(gòu)只要改變模板，就能在一定范圍內(nèi)容 易地改變孔型，并且可以達(dá)到比普通多軸箱更小的孔距。根據(jù)成組加工原理使用多軸箱或多軸頭的組合機(jī)床很適用于大中批量生產(chǎn)。為了在加工中 獲得良好的效果，必需考慮以下數(shù)點(diǎn)： （ 1 ）工件裝夾簡(jiǎn)單，有足夠的冷卻液沖走鐵屑。（2）夾具剛性好，加工時(shí)不形變，分度定位正確。（ 3）使用二組刀具的可能性，以便一組使用

11、，另一組刃磨與調(diào)整，從而縮短換刀停機(jī)時(shí)間。 （ 4）使用優(yōu)質(zhì)刀具，監(jiān)視刀具是否變鈍，鉆頭要機(jī)磨。（ 5）尺寸超差時(shí)能立即發(fā)現(xiàn)。1.2.3 多軸鉆床這是一種能滿(mǎn)足多軸加工要求的鉆床。諸如導(dǎo)向、功率、進(jìn)給、轉(zhuǎn)速與加工范圍等。巴黎 展覽會(huì)中展出的多軸鉆床多具液壓進(jìn)給。其整個(gè)工作循壞如快進(jìn)、工進(jìn)與清除鐵屑等都是自動(dòng)進(jìn) 行。值得注意的是，多數(shù)具有單獨(dú)的變速機(jī)構(gòu)，這樣可以適應(yīng)某一組孔中不同孔徑的加工需要。1.2.4 自動(dòng)更換主軸箱機(jī)床為了中小批量生產(chǎn)合理化的需要，最近幾年發(fā)展了自動(dòng)更換主軸箱組合機(jī)床。（1） 自動(dòng)更換主軸機(jī)床自動(dòng)更換主軸機(jī)床頂部是回轉(zhuǎn)式主軸箱庫(kù)，掛有多個(gè)不可調(diào)主軸箱。縱橫配線盤(pán)予先編好 工

12、作程序，使相應(yīng)的主軸箱進(jìn)入加工工位，定位緊并與動(dòng)力聯(lián)接，然后裝有工件的工作臺(tái)轉(zhuǎn)動(dòng)到 主軸箱下面，向上移動(dòng)進(jìn)行加工。當(dāng)變更加工對(duì)象時(shí)，只要調(diào)換懸掛的主軸箱，就能適應(yīng)不同孔 型與不同工序的需要。(2) 多軸轉(zhuǎn)塔機(jī)床轉(zhuǎn)塔上裝置多個(gè)不可調(diào)或萬(wàn)向聯(lián)軸節(jié)主軸箱，轉(zhuǎn)塔能自動(dòng)轉(zhuǎn)位，并對(duì)夾緊在回轉(zhuǎn)工作臺(tái)的 工件作進(jìn)給運(yùn)動(dòng)。通過(guò)工作臺(tái)回轉(zhuǎn)，可以加工工件的多個(gè)面。因?yàn)檗D(zhuǎn)塔不宜過(guò)大，故它的工位數(shù) 一般不超過(guò) 46 個(gè)。且主軸箱也不宜過(guò)大。當(dāng)加工對(duì)象的工序較多、尺寸較大時(shí)，就不如自動(dòng) 更換主軸箱機(jī)床合適，但它的結(jié)構(gòu)簡(jiǎn)單。(3) 自動(dòng)更換主軸箱組合機(jī)床它由自動(dòng)線或組合機(jī)床中的標(biāo)準(zhǔn)部件組成。不可調(diào)多軸箱與動(dòng)力箱按置在水平底

13、座上，主 軸箱庫(kù)轉(zhuǎn)動(dòng)時(shí)整個(gè)裝置緊固在進(jìn)給系統(tǒng)的溜板上。主軸箱庫(kù)轉(zhuǎn)動(dòng)與進(jìn)給動(dòng)作都按標(biāo)準(zhǔn)子程序工 作。換主軸箱時(shí)間為幾秒鐘。工件夾緊于液壓分度回轉(zhuǎn)工作臺(tái)，以便加工工件的各個(gè)面。好果回 轉(zhuǎn)工作臺(tái)配以卸料裝置，就能合流水生產(chǎn)自動(dòng)化。在可變生產(chǎn)系統(tǒng)中采用這種裝置，并配以相應(yīng) 的控制器可以獲得完整的加工系統(tǒng)。(4) 數(shù)控八軸落地鉆床大型冷凝器的水冷壁管板的孔多達(dá)15000個(gè)，它與支撐板聯(lián)接在一起加工。 孔徑為 20 毫米，孔深 180毫米。采用具有內(nèi)冷卻管道的麻花鉆， 57 巴壓力的冷卻液可直接進(jìn)入切削區(qū)， 有利于 排屑。鉆尖磨成 90供自動(dòng) 定心。它比普通麻花鉆耐用，且進(jìn)給量大。為了縮短加工時(shí)間，以 8

14、 軸數(shù)控落地加工。13 多軸加工趨勢(shì)多軸加工生產(chǎn)效率高，投資少，生產(chǎn)準(zhǔn)備周期短，產(chǎn)品改型時(shí)設(shè)備損失少。而且隨著我國(guó) 數(shù)控技術(shù)的發(fā)展，多軸加工的范圍一定會(huì)愈來(lái)愈廣，加工效率也會(huì)不斷提高。第2普通鉆床改為多軸鉆床2.1 生產(chǎn)任務(wù)在一批鑄鐵連接件上有同一個(gè)面上有多個(gè)孔加工。在普通立式鉆床上進(jìn)行孔加工，通常是個(gè)孔一個(gè)孔的鉆削，生產(chǎn)效率低，用非標(biāo)設(shè)備，即組合機(jī)床加工，生產(chǎn)效率高，但設(shè)備投資大?？梢酝瑫r(shí)完成多但把一批普通立式普通單軸鉆床改造為立式多軸鉆床，改造后的多軸鉆床, 個(gè)孔的鉆、擴(kuò)、鉸、等工序。設(shè)計(jì)程序介紹如下：2.2普通立式鉆床的選型2.2.1計(jì)算所需電機(jī)功率零件圖如圖1所示：W3W9-T&114

15、001零件圖圖1為工件零件圖，材料：鑄鐵 HT2O0料厚：5mm硬度：HBS170-240HBS年產(chǎn) 量：1000萬(wàn)軸承安全1)8102推力球軸承校核P=Fa （表 3.8-54）jj P=4.091N文獻(xiàn)6止聲 l3Lh=30000h（表 13-3）60x960（4.091 丿軸承安全4.3軸坐標(biāo)計(jì)算為方便在多軸箱上鏜孔，因此進(jìn)行軸坐標(biāo)計(jì)算是十分重要的。建立如圖14坐標(biāo)系，多軸箱里尺寸如圖示為220x180mm在多軸箱中心安裝主動(dòng)軸，則主動(dòng)軸坐標(biāo)可知(110，90)，則根據(jù)零件圖，可算出其他各軸坐標(biāo)，分別如圖所示。C171344L5）塑電4（1715,39團(tuán)14軸坐標(biāo)團(tuán)第5章導(dǎo)向裝置的設(shè)計(jì)5

16、. 1導(dǎo)向裝置組成導(dǎo)向裝置主要由導(dǎo)柱、導(dǎo)套、彈簧組成。導(dǎo)柱的上端與多軸箱中間板上的導(dǎo)套滑動(dòng)配合，下端安 裝在夾具的鉆模板上。(1)選擇彈簧用四根彈簧支撐整個(gè)多軸箱，粗略估算多軸箱重量：G =9.8 103 240 200 58 50 10亠 9.8 =497.9N每根彈簧負(fù)荷：F=124.5N選圓柱螺旋壓縮彈簧(表12)文獻(xiàn)7,彈簧中徑D2 = 16.0mm,節(jié)距t =6.640mm，彈簧絲直徑d二1.8mm，工作圈數(shù)n =30,自由高度H o = 140mm.(1)導(dǎo)柱、導(dǎo)套的選擇導(dǎo)柱材料為Gcr15,直徑16mm長(zhǎng)303mm導(dǎo)套材料為 20 號(hào)鋼。第 6 章 接桿刀具接桿一端為梯形螺紋，與

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22、 patents, such as the products and machinery equipment,etc. Now similar to mould mould sandwiches what has been adopted generally ici production technologies,last outer the materials of the epidermis at moulds and in layers is material different on core occasionally, So two a kind of material person

23、 who a certain one inclusives, and core require and have high radiations very, issue and steep shaping and retrieve performance of utilizing etc at 100% by layers of material. Should be fixed relatively by the excellent choice to select the material for use. After injecting the shaping technology an

24、d come out in 15 altogether, can really just popularize and popularize . One a kind of adoptions inject the thick teeth of shaping fails and produces horizontal cross-section altogether. Material to pack nylon epidermis, and pearl material pack the nylon at - - glass layers of material core. A rate

25、that shrinks material of pearl of glass is extremely low in core one, have good size stabilities. Nylon prevent pearl from grains of material easy problem of denuding that produces by epidermis person who give good and lubricated tooth tooth gear wheel. Already developed several kinds and processed

26、the method of improving new-typly at present on the basis of the basic theory of injecting shaping altogether. At however, in the mould and gas assist paint mould mould. Mould have and paint processing method to adopt low molecular weight polymers as the outer material, Gas assist mould mould shapin

27、g to adopt the nitrogen or another kind of gas as the core one( or core ones) material. Produce and process equipment constant to perfect and improve, satisfy of different use newly and the new technologies demands with product design, Inject technology and will become the rich and potential industr

28、ialized extensive production technology method altogether.2. inject by - it compress shapingInject and compress shaping move perpendicular on dividing into mould line direction by medium-sized s of walls at -. Adopt the method at the shaping, fill mould stage and produce pressure drive melting body

29、flow according to process, But this flowed the degree of depth of one melted variably. At flowing one deeply relatively, pressure drop relatively low, so that heavy areas make pieces of shaping excessive to pigeonhole melting body, And has prevented the material in the twinkling of an eye from respo

30、nding, these 2 kinds of factors will hinder the flow of the melting body equally. It injects forming process type make pieces of the 14%s of thickness finally by s of degree of depth, After the plastic has been packed 60% - 75% of the type roughly, stop injecting, a of walls of mould is bulldozed at

31、 the same time , Until make the wall original shaping of one finally. The final size of making one is defined at this stage . If at mould wall at process fulling of more type before moving, this kind of technology is usually called and cast and press shaping. On the whole, cast and press shaping to

32、adopt pressure that become to making one go on and protect and pigeonhole in one a piece of variable the type ones of volumeses. Cast and press stage to increase the stages of density, density and then in lying between and solid state plastic change melting body. Adopt and cast and press way shaping

33、 prepressing discs, remaining stress degree of minimising, Make pieces of have remain stress produce and become phenomenon of refracting. It cast and press shaping improvement type activities types types for kinds of new technology in s of walls,inject its make. Already someone call outside gas to a

34、ssist shaping law the method, actually these are a kind of misunderstanding, Because the gas has not influenced the melting body flow in type of plastic . During routine inject shaping, protecting and press is while a of volume of keeping type does not change , Under the function that the pressure f

35、lows, add and enter more plastics. Unite, Being emerged by the runner position of the high pressure and making a defect probably.3. computers supplementary shapingAdopt computer assist project( cae) design and analyse and help and shorten design cycle and prevent cost from expensive mechanical fault

36、 processing. Commercial emulations daily to indicate size on flowing one code, melt material flows in flowing dishes of system and type with balance, The figure of offeredding and put bestly and runner defining runner at the same time . Calculate pressure of injecting and shut mould want at differen

37、t processing terms and material fix by tonnage. And warping rate combine initial to flow into too very accurate to estimate out person who shrink. What is important is and want and make the design tool help and analyse personnel process and go on the operation judged while studying or in a certain p

38、lan of design skillfully. Understand at results and cant process in order that it is by research object /materials from prerequisite. After consider adopting this kind of method accurate data-in , can make enormous benefit . In addition, economic make design cycle not to be short and needs produce s

39、horter time the analysis. The one that should point out is, commercial cae procedures usually cant be used directly. It fills and imitate and produce valuable experience but the result must rethink its limitation to estimate again . Use modern computers go on and inject shaping simulated test and li

40、mited to pure viscidity fluids only( include the melting plastic of viscoplasticity ). One actual flow form measurable melting body person who flow intoes and performance announce etc. structure by speed, If can carry on the viscoplasticity analysis of high accuracy . At present adopt any other to p

41、rocess way reach this advanced competences, And recent years, at emulation the industrial circle person who take the leads of equipment and the research groups of university already made good progress. Have several a of companies make great efforts and probe emulation technology, in order to be be a

42、ble to be being explained moulding the sex instinct act and process the phenomenon of more reality correctly. For example, get together on the influence that the orientation of the possessive chain is distributed to some physics performance and performance . Processing physics is very complicated, b

43、ut some viscoplasticity is embodied too alike to still totally understood , Perfect the rational processing way and taking shape slow at present even more. These stronger strong ways will be exceeded the production capacity that will be designed at present greatly .4. reversal inject shapingComparat

44、ively speaking, it is that a relatively new inject shaping chooses parameters that the reversal is injected. The greatest difficult point of this technology is lain in when processing the condition suddenly changeses, To the thing that it will be known little about what kind of change behavior plast

45、ic melting body will demonstrate . About the rudimentary knowledge of melting body rheology, is not merely the regular shear . Say exactly , the melting body responds( the viscidity and elastic behavior) the characteristic needing expressing, Not only common stable state flow speed or shear speed an

46、d temperature, but also including pressure and flow the speed in the twinkling of an eye. These characteristics including a lot of content and very difficult to understand. However, if not in heterotypic materials inject respect make substantive progress, need and make and publish many kinds of diff

47、erent the concrete operational procedures of plasticses. Need and increase a in common use one tired to try on law is in order to getting ripe and accurate control method also another. During routine inject shaping, the type immobilizes in a of walls, some situations are left, Still utilize and fill

48、ing on the mould and protect and press and fall section and move the mould wall . Can adopt 2 kinds of different methods : Person who move s of perpendicular on dividing into mould line direction wall; Rotate a of walls of the slipping type . Fill stage rotatory type cores with increasing mould. Thr

49、ough this kind of processing technology, the crooked performance and other mechanical performance of making one has gotten great improvement. Polyphenyl drink the water and polypropylene syringe adopt cup the processing method get great to change and break through the ground 2 a piece of products ju

50、st by second.新型注射成型技術(shù)1. 共注射成型（芯層注射成型）采用共注射成型有助于觀察到制件中獨(dú)特的結(jié)構(gòu)。 塑料“甲”先注射充入部 分型腔，然后塑料：“乙”緊跟著“甲”注射進(jìn)入型腔并保持初始推動(dòng)流動(dòng)壓力場(chǎng)。 根據(jù)表皮區(qū)和芯層的尺寸大小，按正確的比例關(guān)系計(jì)量出“甲”和“乙”的用料量， 可制得 1 個(gè)內(nèi)芯層為“甲”外表完全由“乙”包裹的制件。另外，在化妝品應(yīng)用方面， 有小部分的表皮 “甲”料放在 “乙”料之后注射， 以使?jié)部诓糠值谋砥つ芡耆]合。 用 2 種不同顏色的樹(shù)脂進(jìn)行共注射成型的制件， 形 成一個(gè)容易區(qū)分的表皮和芯層區(qū)間 （認(rèn)識(shí)到所有的注射成型件中存在有類(lèi)似的表皮和 芯層這一點(diǎn)

51、非常重要。 ）如果沒(méi)有先進(jìn)的檢測(cè)技術(shù)， 通常難以區(qū)分表皮芯層的區(qū)域 及其分界面。共注射成型并非一門(mén)新的工藝技術(shù)。英國(guó) ici 公司早在 70 年代就開(kāi)始應(yīng)用 這一技術(shù)， 并取得了包括基礎(chǔ)理論， 生產(chǎn)產(chǎn)品及機(jī)器設(shè)備等幾項(xiàng)專(zhuān)利。 現(xiàn)普遍采用的 ici 生產(chǎn)工藝類(lèi)似“三明治模塑”，由于模塑外層表皮的材料與中間或芯層的材料不 同，因此兩種材料必須有一定的相容性， 并且芯層材料要求具有可高度輻射、 發(fā)泡成 型和 100%回收利用等性能。選用材料應(yīng)經(jīng)多種選擇比較而定。 共注射成型工藝問(wèn)世 15 年后，才真正得以普及推廣。一種采用共注射成型的厚齒輸制作橫截面。表皮材料是非填充尼龍， 而芯層材料是玻璃 -珠料

52、- 填充尼龍。芯層中玻璃珠 粒料收縮率極低， 具有良好的尺寸穩(wěn)定性。 尼龍表皮賦予齒輪齒牙良好的潤(rùn)滑性并避 免了珠粒料容易產(chǎn)生的磨蝕問(wèn)題。基于共注射成型的基礎(chǔ)理論目前已開(kāi)發(fā)出幾種新型加工改進(jìn)方法。 例如，模 內(nèi)“上漆”和氣體輔助模塑成型擴(kuò)大了采用這種工藝的范圍。 模內(nèi)上漆加工方法是采 用低分子量聚合物作為外層材料， 而氣體輔助模塑成型是采用氮?dú)饣蛄硪环N氣體作為 芯層（或部分芯層）材料。隨著產(chǎn)品設(shè)計(jì)與生產(chǎn)加工設(shè)備的不斷完善改進(jìn)，將滿(mǎn)足各 種新應(yīng)用和新技術(shù)的需求， 共注射技術(shù)必將成為富有潛力的工業(yè)化大規(guī)模生產(chǎn)工藝方 法。2. 注射壓縮成型注射壓縮成型中型腔壁移動(dòng)方向垂直于分模線。 采用這種方法成型

53、時(shí)， 在 充模階段， 按工序產(chǎn)生壓力驅(qū)熔體流動(dòng)， 但這一個(gè)流道的深度是可變化的。 在較深的 流道中， 壓力下降得較低， 以使大面積的制件成型中熔體沒(méi)有過(guò)度受壓， 并避免了瞬 間的材料響應(yīng)， 這2種因素同樣會(huì)阻礙熔體的流動(dòng)。 注射成型過(guò)程中， 型腔深度可能 是最終制件厚度的 14%，在塑料填充了大致 60%75%的型腔后， 停止注射，模腔壁周 圍同時(shí)受到推壓，直至最終制件的壁原成型為止。制件的最終尺寸在這階段確定。如果在模壁按工序移動(dòng)之前充滿(mǎn)了型腔， 該種工藝通常稱(chēng)為鑄壓成型。 大體 上，鑄壓成型是在一個(gè)可變體積的型腔內(nèi)采用不變的壓力對(duì)制件進(jìn)行保壓。 鑄壓階段 是增加密度的階段， 密度緊接著在介

54、于熔體和固態(tài)塑料之間起變化。 采用鑄壓方式成 型致密圓盤(pán)，可把殘留應(yīng)力減至最低程度，制件上的殘留應(yīng)力可產(chǎn)生變折射現(xiàn)象。鑄壓成型的改進(jìn)型活動(dòng)式型腔壁是一種新技術(shù)， 其由注射全體制件固化階段 通過(guò)多孔的金屬型腔壁以“保壓”制件。這種方法已有人稱(chēng)為外部氣體輔助成型法， 其實(shí)這是一種誤解， 因?yàn)闅怏w并沒(méi)有影響塑料熔體在型腔內(nèi)的流動(dòng)。 在常規(guī)的注射成 型當(dāng)中， 保壓就是在保持型腔體積不變的同時(shí)， 在壓力流的作用下， 添加入更多的塑 料。 聯(lián)同在型腔內(nèi)的保壓流形成了不均勻的壓力分布，有可能在受高壓的澆口位置 產(chǎn)生制件缺陷。3. 計(jì)算機(jī)輔助成型采用計(jì)算機(jī)輔助工程（cae）對(duì)加工設(shè)計(jì)及分析有助于縮短設(shè)計(jì)周期并

55、可避 免代價(jià)昂貴的機(jī)械失誤。 商業(yè)性仿真代碼常用于流道上標(biāo)明尺寸， 以平衡熔料在流道 系統(tǒng)及型腔內(nèi)的流動(dòng)， 同時(shí)確定澆口的最佳開(kāi)設(shè)置和澆口的數(shù)目。 計(jì)算注射壓力和合 模噸位要根據(jù)不同的加工條件和材料而定。 收縮率及翹曲率結(jié)合初始流向也可準(zhǔn)確估 算出來(lái)。重要的是要使得這種設(shè)計(jì)工具幫助熟練分析人員在某個(gè)設(shè)計(jì)方案或加工研究 時(shí)進(jìn)行判斷的操作。結(jié)果必須理解為以研究對(duì)象和加工 / 材料為前提。當(dāng)考慮采用這 種方法準(zhǔn)確輸入數(shù)據(jù)后， 可取得巨大的效益。 另外，這種分析經(jīng)濟(jì)性可使設(shè)計(jì)周期更 短和所需的生產(chǎn)時(shí)間更短。應(yīng)該提醒注意的是， 商業(yè)性的 cae 程序通常是不可直接使用的。 充模仿真可 產(chǎn)生有價(jià)值的見(jiàn)識(shí)， 但結(jié)果必須重新對(duì)其局限性進(jìn)行重新考慮估計(jì)。 應(yīng)用現(xiàn)代計(jì)算機(jī) 進(jìn)行注射成型模擬試驗(yàn)，僅限于純粘性流體（不包括粘彈性的熔融塑料）。可預(yù)測(cè)熔 體流入型腔的實(shí)際流動(dòng)速率組成結(jié)構(gòu)和性能公布等，如可進(jìn)行高精度的粘彈性分析。 目前所采用的任何其它加工方式都不可能達(dá)到這種先進(jìn)水平， 并且最近幾年來(lái)， 由仿 真設(shè)備的工業(yè)界帶頭者和大學(xué)里的研究小組已取得了良好的進(jìn)展。 有幾家公司正在努 力探索仿真技術(shù)， 以求能正確地解釋更多現(xiàn)實(shí)的塑性行為和加工現(xiàn)象。 例如，聚合物 主鏈的取向?qū)植康奈锢硇阅芎托阅芊植嫉挠绊憽?加工物理學(xué)是非常復(fù)雜的， 而某些 粘