JTK1.2提升絞車滾筒設(shè)計(jì)【說明書+CAD】
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河南理工大學(xué)本科畢業(yè)設(shè)計(jì)(論文)中期檢查表
指導(dǎo)教師: 鄧小玲 職 稱: 講師
所在院(系):機(jī)械與動(dòng)力工程學(xué)院 教研室(系、研究所):機(jī)制教研室
題 目
JTK1.2提升絞車滾筒設(shè)計(jì)
學(xué)生姓名
楊立鑫
專業(yè)班級(jí)
機(jī)制05-1班
學(xué)號(hào)
0503010119
一、進(jìn)度情況說明
1.該選題為JTK1.2提升絞車滾筒設(shè)計(jì),可以對(duì)我們大學(xué)四年所學(xué)知識(shí)進(jìn)行一次全面的練習(xí)。
2.這將對(duì)我們以后的學(xué)習(xí)和工作起到十分有效的幫助,也能達(dá)到一個(gè)綜合訓(xùn)練的效果,又加強(qiáng)了實(shí)際的動(dòng)手動(dòng)腦能力。
3.題目的難易程度很適中,對(duì)我們既是一個(gè)挑戰(zhàn)也是一個(gè)很好的鍛煉提高過程。
4.題目的工作量:要求完成3張以上的A0圖紙,2.5—3萬的說明書一份。
5.選題不但能緊密的結(jié)合生產(chǎn)和實(shí)踐,而且在我們所學(xué)課程的范圍之內(nèi),對(duì)我們
以后不管是科研還是從事實(shí)際的工作都有很大的幫助。
二、階段性成果:
在老師指導(dǎo)和同學(xué)們的幫助之下,我順利的開始本次畢業(yè)設(shè)計(jì)。我在自己查閱資料的過程中,慢慢地理出頭緒,摸索出了設(shè)計(jì)思路。
由于我們這次是JTK1.2提升絞車滾筒設(shè)計(jì),以前接觸這方面的知識(shí)較少,所以在剛開始不是很順利,甚至感到有些無從下手,但是經(jīng)過指導(dǎo)老師的指導(dǎo)、與本組同學(xué)的商量、在工廠實(shí)習(xí)和去系先進(jìn)制造研究所觀看實(shí)物之后, 我逐漸找到設(shè)計(jì)的切入點(diǎn),順利的完成了開題報(bào)告,進(jìn)行了一些前期的工作,并使本次設(shè)計(jì)有了一個(gè)良好的開始。在查閱了一些資料后,已經(jīng)進(jìn)行了計(jì)算設(shè)計(jì),正在整理說明書,并進(jìn)行初步繪制草圖.我將繼續(xù)努力,認(rèn)真完成這次畢業(yè)設(shè)計(jì)。
三、存在主要問題及解決方法
由于對(duì)JTK1.2提升絞車滾筒方面的了解不夠深入,實(shí)際經(jīng)驗(yàn)不足,加之這方面參考資料有限,所以隨著設(shè)計(jì)的進(jìn)行,我遇到了許多新的和更加復(fù)雜的問題,這些問題使我充分認(rèn)識(shí)到了自己在以前學(xué)習(xí)中的不足和自己與一些同學(xué)在專業(yè)知識(shí)方面的差距,所以我要以本次設(shè)計(jì)為契機(jī),加強(qiáng)自己在學(xué)習(xí)上薄弱環(huán)節(jié),爭取使我的畢業(yè)設(shè)計(jì)能夠取得好的成績,也能夠使我所學(xué)的知識(shí)能夠在以后的工作中發(fā)揮更大的作用。
四、指導(dǎo)教師對(duì)學(xué)生在畢業(yè)設(shè)計(jì)(論文)中的紀(jì)律及畢業(yè)設(shè)計(jì)(論文)任務(wù)的完成進(jìn)展等方面的評(píng)語
指導(dǎo)教師: (簽名)
年 月 日
畢
業(yè)
實(shí)
習(xí)
報(bào)
告
姓名:楊立鑫
班級(jí):機(jī)制05-1班
學(xué)號(hào):0503010119
指導(dǎo)老師:鄧小玲
日期:2009年6月5日
前 言
本次畢業(yè)實(shí)習(xí)我們在鄧小玲等老師的帶領(lǐng)下,有針對(duì)性地來到了焦作神華重型機(jī)械制造有限公司以了解該廠一系列產(chǎn)品的生產(chǎn)過程,特別是了解了提升機(jī)械—提升絞車的工作過程和絞車滾筒的構(gòu)造。同時(shí)也收集畢業(yè)設(shè)計(jì)的相關(guān)資料,多向現(xiàn)場的工程技術(shù)人員和工人師傅學(xué)習(xí),也了解我們將要面對(duì)的畢業(yè)后的工作和生活環(huán)境,的確是受益匪淺。
通過這次畢業(yè)實(shí)習(xí)我們學(xué)到了書本上學(xué)不到的許多知識(shí),通過自己動(dòng)手操作機(jī)床將理論和實(shí)踐結(jié)合起來,提高了自己的動(dòng)手能力,為即將走出校門,走上工作崗位的我們起到了一個(gè)承上啟下的作用??偟膩碚f,這次實(shí)習(xí)是非常必要的,也是非常成功的。
在此,感謝鄧小玲指導(dǎo)老師對(duì)我們的指導(dǎo)以及工人師傅的幫助!
一 實(shí)習(xí)目的
生產(chǎn)實(shí)習(xí)是我們機(jī)自專業(yè)知識(shí)結(jié)構(gòu)中不可缺少的組成部分,并作為一個(gè)獨(dú)立的項(xiàng)目列入專業(yè)教學(xué)計(jì)劃中的。其目的在于通過實(shí)習(xí)使學(xué)生獲得基本生產(chǎn)的感性知識(shí),理論聯(lián)系實(shí)際,擴(kuò)大知識(shí)面;同時(shí)專業(yè)實(shí)習(xí)又是鍛煉和培養(yǎng)學(xué)生業(yè)務(wù)能力及素質(zhì)的重要渠道,培養(yǎng)當(dāng)代大學(xué)生具有吃苦耐勞的精神,也是學(xué)生接觸社會(huì)、了解產(chǎn)業(yè)狀況、了解國情的一個(gè)重要途徑,逐步實(shí)現(xiàn)由學(xué)生到社會(huì)的轉(zhuǎn)變,培養(yǎng)我們初步擔(dān)任技術(shù)工作的能力、初步了解企業(yè)管理的基本方法和技能;體驗(yàn)企業(yè)工作的內(nèi)容和方法。這些實(shí)際知識(shí),對(duì)我們學(xué)習(xí)后面的課程乃至以后的工作,都是十分必要的基礎(chǔ)。
二 公司簡介
焦作神華重型機(jī)械制造有限公司(原焦作重型機(jī)械制造有責(zé)任限公司)是集科技開發(fā)、生產(chǎn)經(jīng)營、技術(shù)服務(wù)于一體,具有百年歷史的國家二級(jí)企業(yè),國家二級(jí)計(jì)量單位,省級(jí)?文明單位,中國煤礦機(jī)械裝備公司及河南省煤礦機(jī)械制造公司成員廠。公司現(xiàn)有職工二千多人,其中各類專業(yè)技術(shù)人員300余人,中、高級(jí)專業(yè)技術(shù)職稱人員50余人。擁有固定資產(chǎn)5000萬元,年產(chǎn)值7000萬元,各種機(jī)加工設(shè)備300臺(tái)(套),其中5m立車、5m滾齒機(jī)、大型數(shù)顯落地鏜銑床等精良設(shè)備50臺(tái)(套)。公司技術(shù)力量雄厚,下設(shè)機(jī)械加工、鉚焊、鑄造、熱處理、檢測及安裝等分廠,有先進(jìn)的理化實(shí)驗(yàn)、計(jì)量檢測、產(chǎn)品檢測、信息中心等。該公司面向煤礦、建材、化工、冶金、電力、環(huán)保等行業(yè),可承攬年產(chǎn)120萬噸煤炭設(shè)備、30萬噸水泥成套設(shè)備、15萬千瓦電煤磨設(shè)備及20萬噸純堿成套設(shè)備、0.6—30萬千瓦燃煤電廠環(huán)保設(shè)備制造及安裝,產(chǎn)品遠(yuǎn)銷全國二十六個(gè)省、市、自治區(qū),曾多次為國家重點(diǎn)工程配套。2000年12月獲得中國方圓認(rèn)證委員會(huì)質(zhì)量認(rèn)證中心ISO9001國際質(zhì)量體系認(rèn)證。該公司的質(zhì)量方針是:滿足顧客的需要是我們永恒的追求。質(zhì)量目標(biāo)是:質(zhì)量體系按ISO9001標(biāo)準(zhǔn)保持穩(wěn)定有效運(yùn)行,產(chǎn)品一次交驗(yàn)合格率95%。以高質(zhì)量、低成本、優(yōu)質(zhì)服務(wù)、達(dá)到顧客滿意為宗旨。本公司面向煤礦、建材、化工、冶金、電力、環(huán)保等行業(yè)。多次為國家重點(diǎn)工程配套帶式輸送機(jī),在用戶中享有較高聲譽(yù)。
??? 公司依靠科技進(jìn)步,堅(jiān)持走質(zhì)量效益型道路,形成了從新產(chǎn)品開發(fā)、生產(chǎn)制造、銷售和服務(wù)全過程的質(zhì)量保證體系。作為國家二級(jí)計(jì)量合格單位,公司擁有一套完整的質(zhì)量檢測系統(tǒng),嚴(yán)格的管理程序,先進(jìn)的測試設(shè)備,檢測手段齊全,從原材料進(jìn)廠到產(chǎn)品出廠,每一個(gè)環(huán)節(jié)都進(jìn)行嚴(yán)格檢查。企業(yè)設(shè)有質(zhì)量測試中心,中心有九個(gè)實(shí)驗(yàn)室:化驗(yàn)室、硬度實(shí)驗(yàn)室、金相室、探傷室、力學(xué)實(shí)驗(yàn)室、熱械性能測試室、計(jì)工儀表室、機(jī)量鑒定室、托輥實(shí)驗(yàn)室。各種檢測儀器和設(shè)備30余臺(tái),主要有:大型金相顯微鏡,布洛維硬度計(jì),長度測試儀、超聲波探傷儀、磨損試驗(yàn)機(jī)、高頻疲勞試驗(yàn)機(jī)、X射線探傷儀,各種拖輥性能測試設(shè)備等。通過以上測試手段可以對(duì)我廠產(chǎn)品的成品,半成品以及材料的物理,化學(xué)和機(jī)械性能進(jìn)行測試分析和質(zhì)量控制。我公司技術(shù)力量雄厚,產(chǎn)品設(shè)計(jì)采用計(jì)算機(jī)輔助設(shè)計(jì)和工藝,先后開發(fā)出一批具國內(nèi)先進(jìn)水平的新產(chǎn)品,提高了產(chǎn)品的市場競爭力。
三 實(shí)習(xí)內(nèi)容
①掌握絞車滾筒機(jī)械加工工藝和焊接工藝方面的知識(shí)及方法;
②了解絞車滾筒方面的知識(shí),熟悉常用絞車的結(jié)構(gòu)、選擇、用途等;
③了解絞車滾筒的失效形式等;
④了解企業(yè)生產(chǎn)管理模式,學(xué)習(xí)先進(jìn)的管理方式方法;
⑤熟悉、鞏固大學(xué)所學(xué)的專業(yè)課程方面的知識(shí)
本次實(shí)習(xí)主要是針對(duì)畢業(yè)設(shè)計(jì)而展開的,根據(jù)做設(shè)計(jì)的需要,在本次實(shí)習(xí)中,把重點(diǎn)放在了對(duì)絞車滾筒的了解認(rèn)識(shí)上。
四 提升絞車滾筒
1.絞車滾筒的結(jié)構(gòu)
絞車滾筒是用來纏繞鋼絲繩,并且承受鋼絲繩的拉力所造成的各種載荷的主要部件和傳遞動(dòng)力的元件。滾筒一般由三部分組成,即筒殼、法蘭盤(支輪)和支環(huán)。
4-1鑄焊型滾筒的結(jié)構(gòu)
1——支輪 2——筒殼 3——支環(huán) 4——木襯
筒殼是滾筒最基本和最薄弱的元件,是滾筒的主要承載部分。其厚度一般為,本次設(shè)計(jì)中取為δ=20mm,其結(jié)構(gòu)簡圖如4-1所示。支環(huán)的作用是增加滾筒的穩(wěn)定性。筒殼和支輪的材料為 鋼板。礦井提升機(jī)的運(yùn)轉(zhuǎn)實(shí)踐證明,木襯對(duì)筒殼能起到一定的保護(hù)作用,故設(shè)計(jì)時(shí)在筒殼外裝有木襯。但木襯對(duì)筒殼的保護(hù)只有在筒殼的形狀比較規(guī)則,沒有發(fā)生較大的變形,并且合適的木材制作木襯(現(xiàn)常用柞木、水曲柳或榆木等制作),使木襯與筒殼能各處均勻嚴(yán)密接觸的情況下才是有效的,故在安裝提升機(jī)時(shí),要求筒殼的外形是比較規(guī)則的圓柱體,木襯用上述木材制作,并按規(guī)定車制繩溝。裝設(shè)木襯時(shí),應(yīng)使木襯襯條在長度方向上與筒殼均勻嚴(yán)密的接觸,木襯襯條之間的縫隙應(yīng)盡量予以消除。在使用過程中當(dāng)木襯已經(jīng)磨損時(shí),應(yīng)及時(shí)予以更換。
2.絞車滾筒的分類
根據(jù)制造工藝的不同,可把提升機(jī)的滾筒結(jié)構(gòu)分為鑄造一焊接混合型(支輪為鑄造,滾筒為焊接)和焊接型。
當(dāng)支輪的變形與簡殼的變形相比可以忽略時(shí),稱它為剛性支輪,均為剛性支輪。如支輪的變形與筒殼變形相比不可忽略時(shí),稱它為彈性支輪。它的特點(diǎn)是筒殼與支輪的應(yīng)力分布較均勻。經(jīng)驗(yàn)表明,剛性支輪的結(jié)構(gòu)在制造工藝上較復(fù)雜,而且往往容易出現(xiàn)早期失效。因此,現(xiàn)代大中型提升機(jī)滾筒常采用的彈性支輪滾筒結(jié)構(gòu)。
彈性支輪滾筒這種結(jié)構(gòu)共同的持點(diǎn)是取消了支環(huán),用較厚的簡殼來承擔(dān)載荷,并且支輪改為輻板式 (即在支輪上開有兩個(gè)人孔)或圓環(huán)式。這樣做工藝上較簡單,同時(shí)也可以避免由于焊接工藝不當(dāng)造成加強(qiáng)筋附近的局部應(yīng)力過高。經(jīng)驗(yàn)表明,這種改進(jìn)是成功的。
彈性支輪滾筒結(jié)構(gòu)的不同之處還在于剛性支輪的輻板與軸線垂直,而彈性支輪滾筒的支輪與軸線成某一角度(約3·一6。),初看起來,這種傾斜式輻板似乎可以減少筒殼與支輪連接點(diǎn)的剛度.從而減小其彎應(yīng)力,但由于增加了壓縮應(yīng)力,故對(duì)減小合成應(yīng)力水平并不有效,加上它的制造工藝較為復(fù)雜,故不再傾向于使用它了。
此外,滾筒外一般設(shè)有木襯,并在其上車出繩槽,目的是減少鋼繩與簡殼直接接觸面造成的磨損,并使鋼繩排列整齊。 繩槽有螺旋形及環(huán)形兩種,在單層纏繞時(shí)采用螺旋形繩槽就足以使排繩整齊。
3.絞車滾筒筒殼的失效形式
滾殼的失效形式主要有:
(1) 裂紋
出現(xiàn)于筒殼、支輪及支環(huán)上。筒殼上的裂紋多出現(xiàn)于圓周方向和螺釘孔處。如圖圖4-2所示。支輪的裂紋多出現(xiàn)于螺孔周邊,呈放射狀。支環(huán)的裂紋多出現(xiàn)于焊縫處。
圖4-2 筒殼的裂紋形式示意圖
(a)沿筒殼圓周方向局部開裂;(b)沿焊縫和支輪處局部開裂
1—筒殼;2—支環(huán)
(2)局部變形過大
多數(shù)是筒殼中部塌陷。
(3)連接螺拴被剪斷或彎曲變形過大,造成這些失效的原因是復(fù)雜的,一般來說可能有:
①理論計(jì)算有誤 例如某礦使用的2×4×1.7仿蘇型提升機(jī),根據(jù)正確計(jì)算應(yīng)有3~4個(gè)支環(huán),而實(shí)際只有兩個(gè),故造成卷筒強(qiáng)度不足;
②結(jié)構(gòu)設(shè)計(jì)不良 造成卷筒各部分剛度相差過大。例如所加支輪和支環(huán)的結(jié)構(gòu)不合理形成局部剛性過高從而導(dǎo)致局部應(yīng)力過高,不符合彈性均勻化設(shè)計(jì)原則;
③加工安裝不當(dāng) 例如卷筒不圓,或支環(huán)與筒殼貼合不好等;
④使用維修不當(dāng) 例如過載,以及加速度過大等;
⑤原材料有缺陷 例如內(nèi)部裂紋等;
⑥焊接工藝不當(dāng) 例如焊條或焊接參數(shù)選用不當(dāng),焊接處清洗不凈,以及焊后不凈;熱處理或熱處理不當(dāng)造成焊接殘余應(yīng)力過高等;
⑦原設(shè)計(jì)許用應(yīng)力選取過大 例如蘇制或仿蘇的2×4×1.7和2×4×1.8提升機(jī),標(biāo)準(zhǔn)中可以采用8噸卸式箕斗,鋼繩直徑可達(dá)47.5mm,鋼繩最大靜拉力可分別達(dá)到17.5噸和18噸,而筒殼厚度僅有16mm,其應(yīng)力可達(dá)180~200MPa,因此就很容易出現(xiàn)裂紋。
加工、裝配和安裝質(zhì)量對(duì)筒殼能否良好的工作也有很大的影響。例如筒殼與法蘭盤的結(jié)合處沿圓周方向接觸不嚴(yán)密,局部地方間隙過大(超過0. 5毫米);兩半卷筒的對(duì)口處間隙過大,連接不牢。法蘭盤或輪轂與主軸連接處的切向松動(dòng),游動(dòng)卷筒的法蘭盤或輪轂與主軸之間的間隙過大,或在輪轂與主軸過盈配合的情況過盈量過小等,造成法蘭盤或輪轂在主軸上晃動(dòng)或軸向竄動(dòng),從而給簡殼帶來附加扭曲。焊接結(jié)構(gòu)的卷簡中,主要是焊縫的強(qiáng)度不夠.或焊接內(nèi)應(yīng)力過大。 筒殼外形不規(guī)則,橢圓度過大等等。
上述缺陷均會(huì)使卷筒筒殼失去穩(wěn)定的工作狀態(tài),使用一段時(shí)間后,出現(xiàn)連接螺釘折斷、卷筒發(fā)響等不正常現(xiàn)象。以致在正常負(fù)荷下筒殼變形和開裂,為此,應(yīng)提高加工、裝配和安裝質(zhì)量,使用時(shí)應(yīng)經(jīng)常檢查各連接處的情況,發(fā)現(xiàn)異?,F(xiàn)象時(shí),應(yīng)及時(shí)檢修并處理。卷筒筒殼不要使用有缺陷的鋼板制作,而必須用檢查質(zhì)量合格的鋼板制作。目前,強(qiáng)度低的合金15Mn鋼板得到普遍的應(yīng)用,此種鋼板的強(qiáng)度較45鋼提高30%。
滾筒的作用主要是通過主軸把電動(dòng)機(jī)傳遞給它的轉(zhuǎn)速和轉(zhuǎn)矩轉(zhuǎn)化成繞在它上面的鋼絲繩的線速度,以提升和下放物體。
4. 單繩纏繞式提升機(jī)工作原理示意圖
單繩纏繞式提升機(jī)的工作原地如圖l—卷筒上纏上和纏下來實(shí)現(xiàn)提升和向下運(yùn)動(dòng)。提升機(jī)安裝在地面提升機(jī)房里,鋼絲繩一端固定在卷簡上,另一端繞過天輪后懸掛提升容器。圖4-3所示為單繩纏繞式單卷筒提升機(jī),卷筒上固定兩根鋼絲繩,并應(yīng)使每根鋼絲繩在卷簡上的纏繞方向相反。這樣,當(dāng)電動(dòng)機(jī)經(jīng)過減速器帶動(dòng)卷筒旋轉(zhuǎn)時(shí),兩根鋼絲繩便經(jīng)過天輪在卷筒上纏上和纏下,從而使提升容器在井筒里上下運(yùn)動(dòng)。不難看出,單繩纏繞式提升機(jī)的一個(gè)根本特點(diǎn)和缺點(diǎn)是鋼絲繩在卷筒上不斷的纏上和纏下,這就要求卷筒必須具備一定的纏繞發(fā)面積,以便能容納下根據(jù)井深或提升高度所確定的鋼絲繩懸垂長度。單繩纏繞式提升機(jī)的規(guī)格性能、應(yīng)用范圍和機(jī)械結(jié)構(gòu)等,都是由這一特點(diǎn)來確定的。
單繩纏繞式雙卷筒提升機(jī)具有兩個(gè)卷筒,每個(gè)卷筒上固定一根鋼絲繩,并應(yīng)使鋼絲繩在兩卷筒上的纏繞方向相反,其工作原理和特點(diǎn)與單卷筒提升機(jī)完全相同。
圖4-3 單繩纏繞式提升機(jī)工作原理示意圖
1—卷筒 2—鋼絲繩 3—天輪 4—容器
五 小 結(jié)
該次實(shí)習(xí),真正到達(dá)機(jī)械制造業(yè)的第一前線,了解了我國目前制造業(yè)的發(fā)展?fàn)顩r也粗步了解了機(jī)械制造也的發(fā)展趨勢,在新的世紀(jì)里,科學(xué)技術(shù)必將以更快的速度發(fā)展,更快更緊密得融合到各個(gè)領(lǐng)域中,而這一切都將大大拓寬機(jī)械制造業(yè)的發(fā)展方向。
機(jī)械的發(fā)展趨勢可以歸結(jié)為“四個(gè)化”:柔性化、靈捷化、智能化、信息化. 當(dāng)然機(jī)械制造業(yè)的四個(gè)發(fā)展趨勢不是單獨(dú)的,它們是有機(jī)的結(jié)合在一起的,是相互依賴,相互促進(jìn)的。同時(shí)由于科學(xué)技術(shù)的不斷進(jìn)步,也將會(huì)使它出現(xiàn)新的發(fā)展方向。前面我們看到的是機(jī)械制造行業(yè)其自身線上的發(fā)展。然而,作為社會(huì)發(fā)展的一個(gè)部分,它也將和其它的行業(yè)更廣泛的結(jié)合。21世紀(jì)機(jī)械制造業(yè)的重要性表現(xiàn)在它的全球化、網(wǎng)絡(luò)化、虛擬化、智能化以及環(huán)保協(xié)調(diào)的綠色制造等。它將使人類不僅要擺脫繁重的體力勞動(dòng),而且要從繁瑣的計(jì)算、分析等腦力勞動(dòng)中解放出來,以便有更多的精力從事高層次的創(chuàng)造性勞動(dòng),智能化促進(jìn)柔性化,它使生產(chǎn)系統(tǒng)具有更完善的判斷與適應(yīng)能力。當(dāng)然這一切還需要我們大家進(jìn)一步的努力.
通過這次實(shí)習(xí),在老師和工廠師傅的細(xì)心指導(dǎo)下,我了解了很多有關(guān)珩磨機(jī)以及珩磨頭的知識(shí),并理解了珩磨頭的工作原理,對(duì)畢業(yè)設(shè)計(jì)有著很大的幫助。讓我了解到了工廠的規(guī)模水平、生產(chǎn)流程以及一些常規(guī)產(chǎn)品的制作,對(duì)以后踏入工作單位有著很大的幫助。
河南理工大學(xué)本科畢業(yè)設(shè)計(jì)(論文)開題報(bào)告
題目名稱
JTK1.2提升絞車滾筒設(shè)計(jì)
學(xué)生姓名
楊立鑫
專業(yè)班級(jí)
機(jī)制05-1班
學(xué)號(hào)
0503010119
一、選題的目的和意義:
1.對(duì)絞車滾筒的結(jié)構(gòu)和工作原理有個(gè)初步了解。
2.能夠掌握設(shè)計(jì)的基本原理和方法, 深化所學(xué)的理論知識(shí),提高設(shè)計(jì)計(jì)算的能力。
3.樹立正確的設(shè)計(jì)思路,為以后在工作中遇到相關(guān)問題時(shí)提供解決依據(jù)。
通過本次畢業(yè)設(shè)計(jì),我們把把從專業(yè)基礎(chǔ)課程中所學(xué)得的理論知識(shí),在實(shí)際的設(shè)計(jì)工作中綜
合地加以應(yīng)用,使我們在畢業(yè)設(shè)計(jì)之后能夠熟練使用有關(guān)參考資料、計(jì)算圖表、設(shè)計(jì)手冊;熟悉有關(guān)的國家標(biāo)準(zhǔn)和部門標(biāo)準(zhǔn),為以后成為優(yōu)秀的工程技術(shù)人員打下良好的基礎(chǔ)。
二、國內(nèi)外研究現(xiàn)狀簡述:
滾筒具有結(jié)構(gòu)緊湊、傳動(dòng)效率高、噪聲低、使用壽命長、運(yùn)轉(zhuǎn)平穩(wěn)、工作可靠、密封性好、占據(jù)空間小、安裝維修方便等優(yōu)點(diǎn),并適合在各種惡劣環(huán)境條件下工作,所以目前國內(nèi)外已將電動(dòng)滾筒廣泛應(yīng)用于采礦、冶金、煤炭、交通、能源、煙草、化工、建材、郵電、航空、農(nóng)林等各個(gè)生產(chǎn)建設(shè)領(lǐng)域。
以往的絞車滾筒多為領(lǐng)用車體的動(dòng)力源為輸入動(dòng)力,采用減速箱或其他機(jī)械方式的多級(jí)減速系統(tǒng)將動(dòng)力輸入傳動(dòng)軸;在剎車、制動(dòng)、離合等方面都采用機(jī)械控制。現(xiàn)在的新型滾筒充分利用車體本身的氣動(dòng)和液壓控制,有效地實(shí)現(xiàn)了滾筒的全部動(dòng)作,且動(dòng)作靈活、可靠,成本低,便于維修。
1988年12月左右,我國第一臺(tái)電動(dòng)機(jī)外裝式滾筒先后在自貢市運(yùn)輸機(jī)械總廠和東風(fēng)機(jī)械廠研制成功。以變速傳動(dòng)軸承作為新型減速器的低速微型滾筒1991年在天津叉車廠總廠試制成功。
到目前為止,除我國之外世界上已有較知名氣生產(chǎn)滾筒的廠家有數(shù)十家。其中歐洲如德國有Bsuer、Baumuele、WAT、Interroll、Demag等公司。法國有Drymer、Boyer、Redex、Nervus等公司。英國有Thorite、Richard等公司。美國有Sparks公司,日本有住友商事株式會(huì)社等公司。
三、畢業(yè)設(shè)計(jì)(論文)所采用的研究方法和手段:
1.在圖書館借閱相關(guān)書籍。
2.在學(xué)校數(shù)據(jù)庫查找相關(guān)資料。
3.在網(wǎng)上查找相關(guān)資料。
4.對(duì)找到的資料和數(shù)據(jù)進(jìn)行分析和計(jì)算。
5.整合查到的數(shù)據(jù)和資料開始寫畢業(yè)論文。
6.在編寫過程中征求老師和同學(xué)的意見使論文內(nèi)容更加全面。
四、主要參考文獻(xiàn)與資料獲得情況:
[1] 濮良貴, 紀(jì)名剛.機(jī)械設(shè)計(jì).北京:高等教育出版社,2001.
[2]《機(jī)械設(shè)計(jì)師手冊》編寫組.機(jī)械設(shè)計(jì)師手冊.北京:機(jī)械工業(yè)出版社,1989.
[3] 汪 愷.機(jī)械工業(yè)基礎(chǔ)標(biāo)準(zhǔn)應(yīng)用手冊.北京:機(jī)械工業(yè)出版社,2001.
[4] 孔慶華, 劉傳紹.極限配合與測量技術(shù)基礎(chǔ).上海:同濟(jì)大學(xué)出版社,2002.
[5] 徐 灝.機(jī)械設(shè)計(jì)師手冊.北京:機(jī)械工業(yè)出版社,2000.
[6] 鄒 平.機(jī)械設(shè)計(jì)實(shí)用機(jī)構(gòu)與裝置圖冊.北京:機(jī)械工業(yè)出版社,2007.
[7] 盧耀祖,鄭志強(qiáng).機(jī)械結(jié)構(gòu)設(shè)計(jì).上海:同濟(jì)大學(xué)出版社,2004.
[8] 梁德本,葉玉駒.機(jī)械制圖手冊.北京:煤炭工業(yè)出版社,1983.
[9] 趙 彤.現(xiàn)代實(shí)用氣動(dòng)技術(shù).北京:機(jī)械工業(yè)出版社,2003.
[10] 顧崇銜.機(jī)械制造工藝學(xué).陜西:陜西科學(xué)技術(shù)出版社,1999.
五、畢業(yè)設(shè)計(jì)(論文)進(jìn)度安排(按周說明):
1. 第6周 確定畢業(yè)設(shè)計(jì)題目。
2.第7-8周 從網(wǎng)上和圖書館數(shù)據(jù)庫中查閱相關(guān)資料。
3.第9周 完成開題報(bào)告,交指導(dǎo)老師檢查。
4.第10-14周 開始寫畢業(yè)論文并完成初稿,交指導(dǎo)老師審查。
5.第15-16周 審查后,改進(jìn)完善論文并準(zhǔn)備畢業(yè)答辯。
五、指導(dǎo)教師審批意見(對(duì)選題的可行性、研究方法、進(jìn)度安排作出評(píng)價(jià),對(duì)是否開題作出決定):
指導(dǎo)教師: (簽名)
年 月 日
精密與超精密磨削技術(shù)
摘要: 磨削在現(xiàn)代制造業(yè)中占有重要地位,技術(shù)發(fā)展迅速,國內(nèi)外都采用超精密磨削、精密修整、微細(xì)磨料磨具進(jìn)行亞微米級(jí)以下切深磨削的研究,以獲得亞微米級(jí)的尺寸精度。當(dāng)前磨削除向超精密、高效率和超硬磨料方向發(fā)展外,自動(dòng)化也是磨削技術(shù)發(fā)展的重要方向之一。本文就精密和超精密磨削,砂帶磨削,磨削自動(dòng)化進(jìn)行了研究與論述.
關(guān)鍵詞: ELID磨削技術(shù), 砂帶磨削,磨削自動(dòng)化
、
Precise and ultra microfinishing technology
Abstract:The grinding holds the important status in the modern manufacturing industry, the technological development is rapid, domesticand foreign all uses the ultra microfinishing, the precise conditioning, the tiny grinding compound grinding tool carries on the submicron level
to undercut the deep grinding the research, obtains the submicron levelthe size precision.Outside the current grinding except to ultra precise, the high efficiency and the ultra hard grinding compound direction develops, the automation also is one of grinding technological development important directions.This article on precise and the ultra microfinishing, the belt grinding, the grinding automation has conducted the research and the elaboration。
Key word: ELID grinding technology, belt grinding, grinding automation
1 精密與超精密磨削技術(shù)
國內(nèi)外都采用超精密磨削、精密修整、微細(xì)磨料磨具進(jìn)行亞微米級(jí)以下切深磨削的研究,以獲得亞微米級(jí)的尺寸精度。微細(xì)磨料磨削,用于超精密鏡面磨削的樹脂結(jié)合劑砂輪的金剛石磨粒平均直徑可小至4 μm。日本用激光在研磨過的人造單晶金剛石上切出大量等高性一致的微小切刃,對(duì)硬脆材料進(jìn)行精密磨削加工,效果很好。超硬材料微粉砂輪超精密磨削主要 用于磨削難加工材料,精度可達(dá)0.025 μm。日本開發(fā)了電解在線修整(ELID)超精密鏡面磨削技術(shù),使得用超細(xì)微(或超微粉)超硬磨料制造砂輪成為可能,可實(shí)現(xiàn)硬脆材料的高精度、 高效率的超精密磨削。作平面研磨運(yùn)動(dòng)的雙端面精密磨削技術(shù),其加工精度、切除率都比研 磨高得多,且可獲得很高的平面度, 在工具和模具制造中,磨削是保證產(chǎn)品的精度和質(zhì)量的最后一道工序。技術(shù)關(guān)鍵除磨床本身外、磨削工藝也起決定性的作用。在磨削脆性材料時(shí),由于材料本身的物理特性,切屑形成多為脆性斷裂,磨劑后的表面比較粗糙。在某些應(yīng)用場合如光學(xué)元件,這樣的粗糙表面必須進(jìn)行拋光,它雖能改善工件的表面粗糙度,但由于很難控制形狀精度,拋光后經(jīng)常會(huì)降低。為了解決這一矛盾,在80年代末日本和歐美的眾多公司和研究機(jī)構(gòu)相繼推回了兩種新的磨削工藝:塑性磨削(Ductile Grinding)和鏡面磨削(Mirror Grinding)。
(1)塑性磨削 它主要是針對(duì)脆性材料而言,其命名來源出自該種工藝的切屑形成機(jī)理,即磨削脆性材料時(shí),切屑形成與塑性材料相似,切屑通過剪切的形式被磨粒從基體上切除下來。所以這種磨削方式有時(shí)也被稱為剪切磨削(Shere Mode Grindins)。由此磨削后的表面沒有微裂級(jí)形成,也沒有脆必剝落時(shí)的元規(guī)則的凹凸不平,表面呈有規(guī)則的紋理。
塑性磨削的機(jī)理至今不十分清楚在切屑形成由脆斷向逆性剪切轉(zhuǎn)變?yōu)樗軘?,這一切削深度被稱為臨界切削深度,它與工件材料特性和磨粒的幾何形狀有關(guān)。一般來說,臨界切削深度在100μm以下,因而這種磨削方法也被稱為納米磨削(Nanogrinding)。根據(jù)這一理論,有些人提出了一種觀點(diǎn),即塑性磨削要靠特殊磨床來實(shí)現(xiàn)。這種特殊磨床必須滿足如下要求:
l)極高的定位精度和運(yùn)動(dòng)精度。以免因磨粒的切削深度超過100μm時(shí),導(dǎo)致轉(zhuǎn)變?yōu)榇嘈阅ハ鳌?
2)極高的剛性。因?yàn)樗苄阅ハ鞯那邢髁h(yuǎn)超過脆性磨削的水平,機(jī)床剛性太低,會(huì)因切削力引起的變形而破壞塑性切屑形成的條件。
對(duì)形成塑性磨削的另一種觀點(diǎn)認(rèn)為切削深度不是唯一的因素,只有磨削溫度才是切屑由脆性向塑性轉(zhuǎn)變的關(guān)鍵。從理論上講,當(dāng)磨粒與工件的接觸點(diǎn)的溫度高到一定程度時(shí),工件材料的局部物理特性會(huì)發(fā)生變化,導(dǎo)致了切屑形成機(jī)理的變化。作者從實(shí)踐中找到了支持這種觀點(diǎn)的許多證據(jù):比如在一臺(tái)已經(jīng)服役20多年的精度和剛度不高的平面磨床上磨削SiC陶瓷,用40O0#的金剛石砂輪。工件表面粗糙度小于Rq5μm,表面上看不到脆斷的痕跡。另外德國亞琛工業(yè)大學(xué)的Konig教授作了如下試驗(yàn),在普通的車床上,用激光局部加熱一個(gè)SiN陶瓷試件,即能順利地進(jìn)行車削。這些實(shí)驗(yàn)均間接地說明溫度對(duì)切屑形成機(jī)理有決定性的影響。
(2)鏡面磨削 顧名思義,它關(guān)心的不是切屑形成的機(jī)理而是磨削后的工件表面的特性。當(dāng)磨削后的工件表面反射光的能力達(dá)到一定程度時(shí),該磨削過程被稱為鏡面磨削。鏡面磨削的工件材料不局限于脆性材料,它也包括金屬材料如鋼、鋁和鉬等。為了能實(shí)現(xiàn)鏡面磨削,日本東京大學(xué)理化研究所的Nakagawa和Ohmori教授發(fā)明了電解在線修整磨削法ELID(Electrolytic In-Process Dressing)。
鏡面磨削的基本出發(fā)點(diǎn)是:要達(dá)到境面,必須使用盡可能小的磨粒粒度,比如說粒度2μm乃至0.2μm。在ELID發(fā)明之前,微粒度砂輪在工業(yè)上應(yīng)用很少,原因是微粒度砂輪極易堵塞,砂輪必須經(jīng)常進(jìn)行修整,修整砂輪的輔助時(shí)間往往超過了磨削的工作時(shí)間。ELID首次解決了僅用微粒度砂輪時(shí),修整與磨削在時(shí)間上的矛盾,從而為微粒度砂輪的工業(yè)應(yīng)用創(chuàng)造條件。
ELID(Electrolytic In-Process Dressing)磨削是在磨削過程中,利用非線性電解修整作用和金屬結(jié)合劑超硬磨料砂輪表層氧化物絕緣層對(duì)電解抑制作用的動(dòng)態(tài)平衡,對(duì)砂輪進(jìn)行連續(xù)修銳修整,使砂輪磨粒獲得恒定的突出量,從而實(shí)現(xiàn)穩(wěn)定、可控、最佳的磨削過程,它適用于硬脆材料進(jìn)行超精密鏡面磨削。ELID磨削技術(shù)以其效率高、精度高、表面質(zhì)量好、加工裝置簡單及加工適應(yīng)性廣等特點(diǎn),在日本已較廣泛用于電子、機(jī)械、光學(xué)、儀表、汽車等領(lǐng)域。
ELID磨削原理是金屬結(jié)合劑超硬磨料砂輪與電源正極相接做陽極,工具電極做陰極,在砂輪和電極的間隙中通過電解磨削液,利用電解過程中的陽極溶解效應(yīng),對(duì)砂輪表層的金屬基體進(jìn)行電解去除,從而逐漸露出嶄新鋒利的磨粒,形成對(duì)砂輪的修整作用:同時(shí)形成一層鈍化膜附著于砂輪表面,抑制砂輪過度電解,從而使砂輪始終以最佳磨削狀態(tài)連續(xù)進(jìn)行磨削加工。所以該技術(shù)將砂輪修整與磨削過程結(jié)合在一起,利用金屬基砂輪進(jìn)行磨削加工的同時(shí)利用電解方法對(duì)砂輪進(jìn)行修整,從而實(shí)現(xiàn)對(duì)硬脆材料的連續(xù)超精密鏡面磨削。
ELID鏡面磨削過程可分為準(zhǔn)備階段、電解預(yù)修銳階段、在線電解修整動(dòng)態(tài)磨削階段和光磨階段。準(zhǔn)備階段主要是對(duì)砂輪進(jìn)行動(dòng)平衡和精密整形,減小砂輪的圓度和圓柱度誤差:預(yù)修銳階段使砂輪獲得適當(dāng)?shù)某鋈懈叨群秃侠淼娜菪伎臻g,并形成一層鈍化膜:動(dòng)態(tài)磨削階段形成加工表面:光磨階段則進(jìn)一步提高表面質(zhì)量。
ELID磨削去除材料的機(jī)理與其他鏡面加工有所不同。通常的鏡面加工是通過磨削、研磨和拋光來獲得的。研磨和拋光是以柔性的研磨盤把磨料壓在材料表面并產(chǎn)生相對(duì)運(yùn)動(dòng),磨料借助研磨盤的壓力以滾動(dòng)方式使材料破碎,以滑動(dòng)和滾動(dòng)方式去除破碎后的材料。
而在ELID磨削中,一方面由于磨粒固著在結(jié)合劑中,對(duì)于單顆粒的固著磨粒而言,其有效磨削尺寸只有磨粒尺寸的1/3,磨粒主要以微切削的方式去除材料,所以造成的破碎區(qū)要小得多:另一方面,砂輪表面形成具有一定厚度和彈性且容納有脫落磨料的鈍化膜,成為一種具有良好柔性的研磨膜。精磨時(shí),由于進(jìn)給量很小,鈍化膜的厚度遠(yuǎn)大于磨料的出刃高度,使砂輪基體表層磨料在磨削中不可能直接與工件接觸,砂輪上覆蓋的這層鈍化膜將代替金屬基砂輪參與真正的磨削過程。當(dāng)電解作用完全抑制時(shí),鈍化膜對(duì)工件進(jìn)行光磨。所以ELID磨削實(shí)際上是一種將磨、研、拋合為一體的復(fù)合式精密鏡面加工技術(shù),其中磨粒主要是以滑動(dòng)方式去除工件材料的
ELID磨削技術(shù)是對(duì)金屬結(jié)合劑超硬磨料砂輪在線修整、修銳的復(fù)合磨削技術(shù),它有別于電解磨削、電火花磨削,在精密加工領(lǐng)域獨(dú)樹一幟,具有自身的一些顯著特點(diǎn)。
磨削過程具有良好的穩(wěn)定性和可控性,易于實(shí)現(xiàn)磨削過程的最優(yōu)化: 加工精度高,表面裂紋少,表面質(zhì)量好: 適應(yīng)性廣泛,磨削效率高:裝置簡單,成本低,推廣性強(qiáng)等。
ELID磨削的必備裝置主要有砂輪、電源、電解裝置、電解液和磨床等五個(gè)要素。
ELID磨削對(duì)磨床的要求主要是要有較高的主軸回轉(zhuǎn)精度。
ELID磨削用砂輪的結(jié)合劑應(yīng)具有良好的導(dǎo)電性和電解性能,而結(jié)合劑元素的氧化物或氫氧化物不導(dǎo)電。目前常用的砂輪有鑄鐵纖維結(jié)合劑(CIFB)、鑄鐵結(jié)合劑(CIB)和鐵粉結(jié)合劑(IB)的金剛石砂輪, ELID磨削的電源可以采用直流電源、交流電源、脈沖電源等。電解裝置的主要部分是工具電極。磨床結(jié)構(gòu)不同,工具電極的位置和形狀也不同,電極宜用不銹鋼制造,與砂輪的間隙控制在0. 5~1. 5mm范圍內(nèi),而且應(yīng)與機(jī)床充分絕緣。工具電極固定在絕緣板上,再用調(diào)節(jié)栓將絕緣板固定在砂輪防護(hù)罩上。電極上開有蓄水槽,電解磨削液采用中心送液法,依靠重力和離心力充滿電極間隙。
ELID磨削液兼做電解液,一般采用弱堿性電解質(zhì)水溶液。但結(jié)合劑和磨粒粒度不同,磨削液的主要成分也不同。磨削液對(duì)電解過程中形成的鈍化膜的厚度、性質(zhì)乃至最終的磨削效果都有重要影響。
ELID磨削技術(shù)在我國尚處于研究階段,主要集中在高校,如哈爾濱工業(yè)大學(xué)、大連理工大學(xué)、西安交通大學(xué)、天津大學(xué)、西北工業(yè)大學(xué)等。哈爾濱工業(yè)大學(xué)經(jīng)過幾年的努力,研制成功了ELID磨削專用的脈沖電源、磨削液和砂輪,在國產(chǎn)機(jī)床上開發(fā)出平面、外圓和內(nèi)圓ELID磨削裝置,并對(duì)多種硬脆材料進(jìn)行了ELID鏡面磨削的實(shí)驗(yàn)研究。目前正積極推廣普及該技術(shù),實(shí)現(xiàn)產(chǎn)品化。國內(nèi)已有十幾家單位應(yīng)用該技術(shù),如230廠用于加工動(dòng)壓馬達(dá)零件,23所用于相陣?yán)走_(dá)互易移相單元陶瓷、微晶玻璃、鐵氧體等航天材料零件加工,8358廠用于光學(xué)玻璃非球曲面加工,205所用于光學(xué)玻璃加工,華僑大學(xué)用于加工大理石,福建南安宏偉陶瓷廠用于加工陶瓷等。
盡管ELID磨削技術(shù)在我國的發(fā)展落后于一些工業(yè)發(fā)達(dá)國家,但是ELID磨削技術(shù)在國內(nèi)的研究和應(yīng)用基礎(chǔ)已經(jīng)具備。特別是該技術(shù)顯著的特點(diǎn),尤其適合我國國情。隨著該技術(shù)的進(jìn)一步普及推廣,相信有越來越多的專家和學(xué)者認(rèn)識(shí)到這項(xiàng)技術(shù)的重要性和它潛在的經(jīng)濟(jì)價(jià)值,越來越多的企業(yè)重視并采用該技術(shù),從而促進(jìn)我國傳統(tǒng)產(chǎn)業(yè)的改造和高新技術(shù)的發(fā)展。ELID磨削技術(shù)作為一種新型的鏡面加工方法,具有廣闊的應(yīng)用前景和很大的實(shí)用價(jià)值。
精密與超精密磨削技術(shù)
摘要: 磨削在現(xiàn)代制造業(yè)中占有重要地位,技術(shù)發(fā)展迅速,國內(nèi)外都采用超精密磨削、精密修整、微細(xì)磨料磨具進(jìn)行亞微米級(jí)以下切深磨削的研究,以獲得亞微米級(jí)的尺寸精度。當(dāng)前磨削除向超精密、高效率和超硬磨料方向發(fā)展外,自動(dòng)化也是磨削技術(shù)發(fā)展的重要方向之一。本文就精密和超精密磨削,砂帶磨削,磨削自動(dòng)化進(jìn)行了研究與論述.
關(guān)鍵詞: ELID磨削技術(shù), 砂帶磨削,磨削自動(dòng)化
Precise and ultra microfinishing technology
Abstract:The grinding holds the important status in the modern manufacturing industry, the technological development is rapid, domesticand foreign all uses the ultra microfinishing, the precise conditioning, the tiny grinding compound grinding tool carries on the submicron level
to undercut the deep grinding the research, obtains the submicron levelthe size precision.Outside the current grinding except to ultra precise, the high efficiency and the ultra hard grinding compound direction develops, the automation also is one of grinding technological development important directions.This article on precise and the ultra microfinishing, the belt grinding, the grinding automation has conducted the research and the elaboration。
Key word: ELID grinding technology, belt grinding, grinding automation
1 is accurate with rubing the technology of paring ultraprecisionly
Adopt and waste paring ultraprecisionly, repairing accurately both at home and abroad, it has research that cuts and is rubed pared deeply of under submicro grade that very small abradant is rubed, in order to obtain the size precision of grade of submicro. Very small abradant rub, sharpen, used in ultraprecision surface of the mirror resin sharpened to rub combine pharmaceutical diamond grit of emery wheel average diameter little to 4 μ m very. Japan cuts out a large amount of and waits for high identical cutting the edge on the artificial single crystal diamond that is ground smallly with the laser, rub and pare processing to the hard fragile material accurately, very effective. Ultra hard material little powder emery wheel ultraprecision to rub, pare, use mainly for, rub, sharpen difficult to process materials, the precision can reach 0.025 μ m. Japan has developed and repaired(ELID) electrolytically online The ultraprecision surface of the mirror rubs the technology of paring, can use ultraly and slightly (or ultra little powder) Ultra hard abradant make emery wheel become, perhaps, can realize hard fragile high precision of material, a high-efficiency one ultraprecision to rub paring. Make level pairs of terminal surface to grind sport accurate to rub technology of sharpening, machining accuracy its, person who excise high much than to grind, and can get very high level degree, in tool and mould are made, it is a process of precision and end of the quality of guaranteeing the products to rub and pare. Technological key besides the grinding machine, rub, sharpen craft play a decisive role. While rubing and paring the fragility material, because of the physical characteristic of material, it is mostly the fracture of fragility that the smear metal is formed, the surface after rubing pharmaceutical is more coarse. , like the optical component, such a coarse surface must carry on the polishing in some application occasions, although it can improve the surface roughness of the work piece, because it is very difficult to control the form precision, will often be reduced after the polishing. And numerous company and research institution of America and Europe push back two rubing crafting of sharpening new in succession for solve contradiction this, doomsday in the 1980s originally: Plasticity is rubed and pared (Ductile Grinding) Rubed and pares (Mirror Grinding) with the surface of the mirror .
(1)Plasticity rubs and pares it mainly regarding fragility material, it names smear metal formation mechanism that the source comes from this kind of craft, rub it while paring the fragility material, it is similar to plasticity material that the smear metal takes shape, the smear metal is excised from matrices by the grit through the form of shearing. So this kind rubs way of paring and known as shearing and wasting paring (Shere Mode Grindins) sometimes . Rub surface sharpen, split grade take shape, have fragile yuans of rule must peel off, full of bumps and holes a little, the surface presents regular lamination.
Plasticity mechanism sharpened to rub clear in smear metal forming from fragile and broken to shear, change against sex into, mould, break very much so far, all these are pared and known as the borderline to cut the depth deeply, it and work piece material characteristic have something to do with the geometirc form of the grit. Generally speaking, borderline cut depth under 100μ m, therefore this kind rub, sharpen method known as nanometer rub and sharpen (Nanogrinding) too . According to this theory, some people have proposed a kind of view, plasticity will be realized by the special grinding machine when being rubed and pared. Such special grinding machine must meet the following requirement:
l)Extremely high localization precision and movement precision. In case that because result in changing into the fragility and rub and pare when the cutting of the grit exceeds 100μ m deeply.
2)Extremely high rigidity. Because plasticity rubs the cutting strength pared exceeds the fragility and rubs the level pared far, the lathe rigidity is too low, will arising from cutting strength deformation destroy plasticity terms that smear metal form.
Rub another view pared to show to the plasticity of forming that it is not the only factor to cut the depth, it is a smear metal key from fragility to plasticity transition to only rub the temperature of paring. Theoretically, when the temperature that grit and contact of the work piece are lighted is high to certain extent, some physical characteristic of the work piece material will change, has caused the change of smear metal formation mechanism. The author has found a lot of evidences of supporting this kind of view from practice: For example on active service 20 precision for more than year and rigidity high level grinding machine rub and sharpen SiC pottery already in one, use diamond emery wheel of 40O0 #. The surface roughness of the work piece is below Rq5μ m, is outwardly less than the fragile trace that breaks. In addition Konig professor of German Aachen polytechnical university has tested as follows, on the ordinary lathe, heat a SiN pottery with laser part and try one, can carry on turning smoothly. These experiments prove indirectly temperature have decisive influence on smear metal formation mechanism.
( 2) The surface of the mirror is as its name suggests rubed and pared, what it cared about is not but the mechanism that smear metal forms rubs the characteristic of the surface of work piece after paring. When the surface of work piece after rubing and paring reflects all ability and becomes certain, it's time to rub the course of paring and known as the surface of the mirror to rub and pare. The surface of the mirror rubs the work piece material pared and does not confine to the fragility material, it includes metal material such as steel, aluminium and molybdenum,etc. too. In order to be able to realize the surface of the mirror is rubed and pared, physical and chemical Nakagawa of research institute, Tokyo University of Japanese, and Ohmori Professor invent electrolytic to repair and rub and sharpen law ELID online ( Electrolytic In-Process Dressing) .
The surface of the mirror rubs the basic point of departure pared: Should reach it the border, must enable and use the granularity of grit as small as possible, for example granularity 2μ m and even 0.2μ m. Before ELID invents, one degree of emery wheels is being employed little commercially in the particle, the reason is that particle one degree of emery wheels is extremely easy to stop up, the emery wheel must be often repaired, repair assisting time and often exceeding the working time to pare of wasting of the emery wheel. When ELID settlement for the first time only uses particle one degree of emery wheels, repair and waste the contradiction pared on time, thus create conditions for industry of one degree of emery wheels employ the particle.
ELID(Electrolytic In-Process Dressing) It is in the course of rubing and paring to rub and pare, utilize non-linear to repair function with metal combine pharmaceutical ultra hard abradant emery wheel top layer oxide insulating barrier to electrolytic dynamic equilibrium of inhibitory activity while being electrolytic, repair and repair sharp the emery wheel continuously, make the grit of emery wheel obtain invariable outstanding quantity, thus realize steady, controllable, best rubing the course of paring, it is suitable for the hard fragile material and rub and pare the ultraprecision surface of the mirror. ELID rub technology of sharpening until their with high efficiency, precision high, surface of high quality, processing equipment simple processing adaptability characteristic such as being wide, already been used in fields such as electron, machinery, optics, instrument, car,etc. more extensively.
ELID rub, sharpen principle whether metal combine pharmaceutical ultra hard abradant emery wheel and power positive pole meet and make positive pole, the tool electrode is made the negative pole, through rubing and paring the liquid electrolytically in the interval of emery wheel and electrode, utilize the positive pole in electrolytic course to dissolve the effect, remove the metal matrices of the top layer of emery wheel electrolytically, thus the brand-new and sharp grit emerges gradually, form the repairment function on the emery wheel: Form membrane of a layer of passivation at the same time and adhere to the surface of emery wheel, it is excessively electrolytic to inhibit the emery wheel, make emery wheel with best to rub, sharpen state rub and pare processing continuously all the time. So this technology repaired the emery wheel and rubed the course of paring to conbine together, ones that utilized the emery wheel of metal base to rub and pare processing utilized the electrolytic method to repair the emery wheel simultaneously, thus realize that rubs and pares the continuous ultraprecision surface of the mirror of the hard fragile material.
ELID surface of the mirror rub, sharpen course can divide into preparatory stage, electrolytic to build sharp stage, online to repair, rub the stage of sharpening and only rub stage dynamically while being electrolytic in advance. Preparatory stage mainly carry on the dynamic equilibrium to the emery wheel and have a facelift accurately, reduce one degree of errors of round degree and cylinder of the emery wheel: Repair sharp stage highly making the emery wheel get appropriate producing the edge and rational holding space of bits in advance, form membrane of a layer of passivation: Waste the stage of paring and form and process the surface dynamically: Only waste stage and further improve surface quality.
ELID rubs and pares the mechanism and other surface of the mirror which removes the material to process to some extent differently. The common surface of the mirror is processed and got by rubing paring, grinding and polishing. It is by grinding one and pressing abradant on the surface of material and producing the relative motion of flexibility to grind with the polishing, abradant makes the material broken by way of rolling through the pressure of grinding one, the material after it is broken to remove by way of slipping and rolling.
In ELID rubs and pares, on one hand because the grit is firm in combining pharmaceutical, as to firm grit of the single particle, it rubs and pares 1/3 with grit size of size effectively, the grit removes materials in a manner to cut a little mainly, so the broken district caused is much smaller: On the other hand, the surface of emery wheel is formed to have certain thickness and elasticity and hold coming off the passivation membrane of the abradant, becoming one has grinding the membrane of good flexibility. While finishing grind, because it is very small to enter the giving amount, the thickness of the membrane of passivation is far greater than producing edge height of abradant, make emery wheel base body surface layers of abradant in rub sharpen, keeping in touch with the work piece directly while being impossible, the passivation membrane that cover with at the emery wheel replace metal base emery wheel participate in real rubing the course of sharpening. When electrolytic function is totally inhibited, the membrane of passivation only rubs the work piece. So ELID rubs and pares in fact that one kind will rub, grind, throw the complex type process technology of accurate surface of the mirror united, among them the grit mainly removes the work piece material by way of slipping
ELID rub, sharpen technology to combine to metal pharmaceutical ultra hard abradant emery wheel repair, build sharp complex rub the technology of sharpening online, it is electrolytic to rub, sharpen for it to different from, electric spark rub, sharpen, in accurate to process field take the course of its own, some prominent characteristics with oneself.
Rubing the course of paring has good stability and controllability, it is apt to realize rubing optimization the most which pare the course: The machining accuracy is high, there is few crackle of surface, the surface is of high quality: Adaptability is extensive, rub and pare with high efficiency: The device is simple, with low costs, the popularizing is strong.
What ELID rubs and pares must fit and mainly have five key elements such as emery wheel, power, electrolytic device, electrolytic liquid and grinding machine fully.
ELID should have higher main shafts to turn the precision round to pare requirements for grinding machine to rub.
ELID should have good electric conductivity and electrolytic performance to pare with combination pharmaceutical of the emery wheel to rub, the oxide or caustic combining the pharmaceutical element does not conduct. The present commonly used emery wheel has casting iron fibers to combine pharmaceutical (CIFB) , the casting iron combines pharmaceutical (CIB) Combine pharmaceutical (IB) with the iron powder Diamond emery wheel,it rub ELID ones that sharpen can last direct current source, alternating current source, pulse power,etc. the powers. The main part of the electrolytic device is a tool electrode. The structure of the grinding machine is different, position and form of the tool electrode are different, the electrode should be made of stainless steel, control with the interval of the emery wheel in 0. 5- 1. In 5mm range, and should be fully insulating with the lath
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