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以,注射壓力合格。模具型腔內(nèi)的脹型力,則式中,是型腔的平均計算壓力值,通常取注射壓力的20%40%,大致范圍為2540MPa。表41可得該注射機的公稱鎖模力,鎖模力安全系數(shù)為這里取,則<所以,注射機鎖模力合格。主流道的形狀為圓錐形,以便熔體的流動和開模時主流道凝料的順利拔出。另外,由于其與高溫塑料熔體及注射機噴嘴反復(fù)接觸,因此設(shè)計中常設(shè)計與可拆卸更換的澆口套。(2) 主流道小端直徑:d=注射機噴嘴尺寸+()mm=(+)mm=8mm。2. 主流道的凝料體積3. 主流道當(dāng)量半徑4. 主流道澆口套形式主流道襯套為標(biāo)準(zhǔn)件可自行選購。對材料的要求較嚴(yán)格,因而盡管小型注射模可以將主流道澆口套與定位圈設(shè)計成一個整體,但考慮上述因素通常還是分開來設(shè)計,以便于拆卸更換。設(shè)計中常采用碳素工具鋼(T8A或T10A),熱處理淬火表面硬度為5055HRC,如圖84所示。本設(shè)計對塑件的分析采用整體式。如圖85所示。對于成型塑件斜面上的孔的活動鑲塊來說,由于脫模時與上模仁的磨損嚴(yán)重,因此鋼材選用高合金模具鋼738。 各模板尺寸的確定1. A板尺寸。綜合考慮,A板取200mm。B板是凹模板,綜合取150mm。墊板=推出行程+推板厚度+推桿固定板+(5~10)mm=95+25+30+(510)=155~160mm。4.模架外形尺寸:650750571(mm)。2.模具高度尺寸:571mm,因為:<<校驗合格。 冷卻水線的設(shè)計本設(shè)計中,由于型芯太深,所以冷卻的方式很重要。圖86 型芯的冷卻方式設(shè)計 導(dǎo)向與定位結(jié)構(gòu)設(shè)計注射模的導(dǎo)向機構(gòu)用于動、定模之間的開合模導(dǎo)向和脫模機構(gòu)的運動導(dǎo)向。模外定位是通過定位圈使模具的澆口套能與注射機噴嘴精確定位;而模內(nèi)定位機構(gòu)則通過導(dǎo)柱導(dǎo)套進行合模定位。 總裝配圖和部分零件圖的繪制1.如圖87所示為模具裝配圖,利用CAD外掛“燕秀工具箱”繪制。圖88 模具零件圖結(jié) 論此次畢業(yè)設(shè)計我們做的課題是三地自行車的工業(yè)設(shè)計與模具設(shè)計,從這次設(shè)計,我們學(xué)到了很多東西。2.雖然這次設(shè)計是簡化設(shè)計,但是很多動作也要有相應(yīng)的機構(gòu)與之對應(yīng),通過這些機構(gòu)的設(shè)計,讓我又鞏固和深化了所學(xué)的機械理論知識。4.模具設(shè)計部分,除了對注塑模具設(shè)計的理論知識鞏固之外,對用Pro/Engineer進行模具設(shè)計的過程以及常見的問題也有了一個更深的認(rèn)識??偠灾@次設(shè)計讓我積累了很多寶貴的經(jīng)驗,為以后的工作打下了堅實的基礎(chǔ)。孟老師多次詢問設(shè)計進程,并為我指點迷津,幫助我開拓設(shè)計思路,精心點撥、熱忱鼓勵。在此,再一次對孟老師表示感謝!45參考文獻[1] [期刊論文] 2001(06) [2] [期刊論文]哈爾濱工業(yè)大學(xué)學(xué)報 2003(02)[3] David A.E,Corinne M B,Cauley M,et a1.Mobility studyfor a lunar[J].Mobile Robots III,1988(1):263—270.[4] Brian D H.Chris V.The challenges of designing the rockerbogie suspension for the mars exploration rover[C]//Proc. of the 37th Aerospace Mechanisms Symposium,2004.[5] Brian D V The challenges of designing the rockerbogie suspension for the mars exploration rover 2004[6] 2008(2)[7] 鄧宗全,胡明.自行車的運動學(xué)建模.中國機械工程.14卷22期,2003,11[8] 王左偉.桀斌.六輪自行車運動學(xué)建模與分析,宇航學(xué)報,第24卷第5期,2003,9[9] Dong Hun Shin,Kyung Hcon Park Velocity Kine∞natic Modeling for Wheeled Mobile Robots.International Conference or Robotics&Automation So。s petitors. The real reason is petition from interest groups, says He Zuoxiu, a renowned theoretical physicist and academician at the Chinese Academy of Sciences. 地方官員常用的這樣的借口來拒絕電動自行車:鉛酸電池會污染環(huán)境;電動車會干擾機動車輛行駛,阻塞交通;特別是對公交系統(tǒng)造成巨大沖擊。中國科學(xué)院著名理論物理學(xué)家,院士何祚庥一針見血地指出:“真正的原因就是來自利益集團的競爭。s the automobiles, he adds. And he says transit operators and manufacturers should be forced to pete with the electric bikes by offering more efficient services and cheaper, cleaner vehicles. The problem, he explains, is that electricbike manufacturers are insignificant next to the other interest groups, particularly the car makers that are attracting billions of dollars of foreign investment. The automotive industry is identified as a pillar industry in China39。他說反對電動車的理由沒有一條真正站得住腳:汽車上用的也是鉛酸電池,他特別補充:“真正的污染源不是電動車,而是汽車。但問題是,與其它競爭者相比,電動車廠商微不足道,特別是汽車產(chǎn)業(yè),吸引了數(shù)十億美元的外國投資。 Back with surpri Although the odds against them are daunting, electricbike manufacturers are pushing sing success. The mastermind of one of the most highprofile battles is Ni Jie, president of Luyuan Electric Vehicle Co., a privately owned manufacturer that has a pragmatic approach to the market, a sizable Ramp。綠源電動車公司的董事長倪捷是代表電動車產(chǎn)業(yè)界的靈魂人物,他從一家小企業(yè)開始艱苦創(chuàng)業(yè),以務(wù)實的態(tài)度開拓市場,并取得成規(guī)模的研究開發(fā)成果,對中國電動車的技術(shù)發(fā)展有獨到的見解。s general manager, Hu Ji Hong, Ni39。九年前,綠源現(xiàn)任總經(jīng)理胡繼紅(倪捷的妻子)制造出第一臺樣機,綠源公司成立了,隨后在倪捷和胡繼紅的領(lǐng)導(dǎo)下,公司改為私營,并且從最初的投資者手里買下了所有產(chǎn)權(quán)。 To find Luyuan EV, you must head off the beaten track to Jinhua, an industrial metropolis of 1 million people that is tucked into the unbroken sprawl south of Shanghai that is Zhejiang province. In the chairman39。t have the solution, the people will behave in their own ways, says Ni. There39。這是浙江省的一座城市,人口百萬,工業(yè)重鎮(zhèn)。倪捷的辦公室坐落在辦公樓的一角,寬敞舒適,是公司里為數(shù)不多的帶暖氣的房間之一,寒冷的二月里,這一點顯得尤為突出。他說,在中國的大多數(shù)城市里,交通是個首要問題,電動車是昂貴的轎車和擁擠的公交車的首選替代品和補充品?!薄 i took people power to surprising limits in 2003 when officials in Fuzhou, the capital of neighboring Fujian province, decided to ban electric bicycles—shutting off what until then had been one of Luyuan39。2003年夏天,當(dāng)時,綠源最大市場之一是毗鄰的福建省省會福州市,但是該市的政府卻要明令封殺電動車,不但不給電動車執(zhí)照,而且禁止銷售,他們沒收了綠源專賣店里的20輛電動自行車。此次,廠商聯(lián)手,迫使市政府無條件發(fā)還了無理沒收的電動車。 Far more valuable, says Ni, was the sympathetic coverage they received from national media and the warning that attention sent to other municipalities. What we told other governments is that if they do the same as Fuzhou, there will be some trouble, he says. 倪捷認(rèn)為此次福州事件更深遠(yuǎn)的意義在于贏得了全國媒體的廣泛關(guān)注和支持,并且也給其它(反對電動車的)地方政府有一點警示作用?!? Conflict over electric bikes isn39。s latest machine doesn39。 it rumbles right over it. Luyuan calls its new product the LEV, short for light electric vehicle, and Ni openly admits that it39。s Web site calls it an electric motorcycle, and that seems fitting: the LEV weighs in at 95 kg。 and its 500watt CPUcontrolled motor propels it to 35 km/h. $ 圍繞電動車引發(fā)的沖突并不只局限于地方政府和生產(chǎn)廠家,中國自行車協(xié)會也和一些廠商(包括綠源)在產(chǎn)品細(xì)節(jié)上發(fā)生分歧,諸如何種兩輪車才可以上路等。 例如,很多踏板電動車配置了騎行功能不好的腳踏,并有限制速度的附加裝置。綠源公司的一款最新產(chǎn)品已經(jīng)不再被現(xiàn)有的電動自行車標(biāo)準(zhǔn)所限制,綠源把這種新車型被稱做LEV,輕型電動車的縮寫。在綠源的網(wǎng)站上它被稱為“電動摩托車”:車重95公斤,配備48伏20安時的電池,電機的輸出功率高了一倍,達到500瓦,用CPU控制的電機可以將時速提高到35公里。s greater weight. The LEV employs an electric drum brake that, Ni claims, stops it faster than the cantilever brakes used on gardenvariety electric bikes could. A is also in the works that would boost braking power by using the inhub motor as a generator to pull energy out of the wheels, extending the vehicle39。在不到一個小時內(nèi),一位25歲的年輕人和一位上班族母親相繼開走了兩輛。 倪捷樂觀地相信,政府在看到LEV的普遍使用之后,會給予正式許可的。倪捷解釋道:LEV裝有電鼓閘,它的剎車效果比各種各樣電動車常用的懸臂閘要好得多。 Ever the entrepreneur, Ni sees the success of the LEV as a step toward bigger and better things. He already has his eye on the market for small delivery vehicles, and he even imagines Luyuan making electric cars and challenging the major automakers. They are investing money, saying we are going to change the gasoline system to electric, he points out. But will the big panies really be willing to destroy their own factories to build the new ones? In Ni39。他已經(jīng)開始關(guān)注小型電動運輸車輛的市場,甚至夢想有一天,綠源能夠生產(chǎn)出自己的小型電動汽車,與大公司競爭?!蹦呓葜赋觯暗?,這些大公司他們真的愿意毀掉現(xiàn)有的工廠去建設(shè)新的工廠嗎?”依倪捷看來,一批富有進取心的小企業(yè),就像綠源這樣的,更有可能推動電動車革命,因為這樣做他們一無所失