礦用提升機(jī)的整體設(shè)計(jì)含開題及6張CAD圖
礦用提升機(jī)的整體設(shè)計(jì)含開題及6張CAD圖,提升,晉升,整體,總體,設(shè)計(jì),開題,cad
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XXX設(shè)計(jì)(XXX)中期檢查表
指導(dǎo)教師: 職 稱:
所在院(系): 教研室(研究室):
題 目
礦井提升機(jī)的整體設(shè)計(jì)
學(xué)生姓名
專業(yè)班級
學(xué)號
一、選題質(zhì)量:(主要從以下四個(gè)方面填寫:1、選題是否符合專業(yè)培養(yǎng)目標(biāo),能否體現(xiàn)綜合訓(xùn)練要求;2、題目難易程度;3、題目工作量;4、題目與生產(chǎn)、科研、經(jīng)濟(jì)、社會(huì)、文化及實(shí)驗(yàn)室建設(shè)等實(shí)際的結(jié)合程度)
選題符合機(jī)械設(shè)計(jì)專業(yè)的培養(yǎng)目標(biāo),能夠體現(xiàn)綜合訓(xùn)練的要求。設(shè)計(jì)任務(wù)難易程度較難,工作量較大。所選題目礦井提升機(jī)的設(shè)計(jì)與實(shí)際貼合比較緊密,在實(shí)際的應(yīng)用中比較廣泛。在設(shè)計(jì)過程中,對機(jī)器的零件的設(shè)計(jì)和計(jì)算對我來說是以往所學(xué)知識(shí)的總結(jié)和應(yīng)用,所以能夠滿足綜合訓(xùn)練的要求。礦井提升機(jī)在設(shè)計(jì)過程中,對于我來說還是具有很大的難度,對于這方面的了解不是很多,且這方面的資料也是比較少,所以這對我來說是一個(gè)挑戰(zhàn)。
2、 開題報(bào)告完成情況:
順利完成了開題報(bào)告,同意開題。
經(jīng)過指導(dǎo)老師的指導(dǎo)和大量的閱讀文獻(xiàn)資料,我逐漸找到了設(shè)計(jì)的切入點(diǎn),順利的完成了開題報(bào)告,并有了一定的成果和進(jìn)行了一些前期的工作。目前本設(shè)計(jì)已經(jīng)進(jìn)入了說明書編寫階段,在以后工作的中我將繼續(xù)努力,認(rèn)真完成這次畢業(yè)設(shè)計(jì)。
三、階段性成果:
1.對本次設(shè)計(jì)進(jìn)行了方案確定,初步完成了提升機(jī)傳動(dòng)部分主要
參數(shù)的確定,并完成了一些零件的選型和設(shè)計(jì)計(jì)算。
2.到目前為止,已完成開題報(bào)告、實(shí)習(xí)報(bào)告、部分說明書和零件圖。
3.進(jìn)一步對整體說明書和完整的圖紙繪制做準(zhǔn)備工作。
四、存在主要問題:
1.對礦井提升機(jī)了解的不夠,技術(shù)方面上不是太成熟。
2.獲得的資料有限。
3.論文初稿的內(nèi)容還不豐富,思考問題還不夠全面,對材料缺少認(rèn)真度量。
4. 局部結(jié)構(gòu)設(shè)計(jì)思路不是很清晰,缺乏經(jīng)驗(yàn)。
五、指導(dǎo)教師對學(xué)生在畢業(yè)實(shí)習(xí)中,勞動(dòng)、學(xué)習(xí)紀(jì)律及畢業(yè)設(shè)計(jì)(論文)進(jìn)展等方面的評語
指導(dǎo)教師: (簽名)
年 月 日
目 錄
一、工廠的介紹
二、礦機(jī)提升機(jī)的學(xué)習(xí)
(1)提升機(jī)的分類及工作原理
(2)提升機(jī)的使用場合
(3)提升機(jī)的規(guī)格型號
(4)提升機(jī)的基本參數(shù)
(5)主要部件及功能
三、學(xué)習(xí)有關(guān)畢業(yè)設(shè)計(jì)的相關(guān)知識(shí)
內(nèi)裝式提升機(jī)的國內(nèi)外發(fā)展?fàn)顩r及其優(yōu)點(diǎn)
一、工廠的介紹
中航光電科技股份有限公司(158廠)隸屬中國航空工業(yè)集團(tuán)公司,是國內(nèi)規(guī)模最大的專業(yè)從事高可靠光、電連接器研發(fā)與生產(chǎn),同時(shí)提供全面光、電連接技術(shù)解決方案的高科技企業(yè)。公司于2007年11月1日在深圳證券所上市,是中國首家整體上市的軍工企業(yè)。
公司致力于光、電連接技術(shù)研究和產(chǎn)品開發(fā),2010年被授予“國家認(rèn)定企業(yè)技術(shù)中心”。擁有光、電連接工程技術(shù)研究中心。自主研發(fā)了各類連接器300多個(gè)系列、23萬多個(gè)品種,產(chǎn)品主要包括圓形、矩形、光纖、濾波、防雷、抗核電磁脈沖、射頻同軸、液冷連接器,同時(shí)提供光模塊、光端機(jī)、光纖網(wǎng)絡(luò)、高速傳輸、線纜組件、系統(tǒng)集成等光、電連接技術(shù)解決方案。產(chǎn)品以其專業(yè)化、高可靠的性能,先后獲得國家創(chuàng)造發(fā)明獎(jiǎng)、全國科學(xué)大會(huì)獎(jiǎng)、國家重點(diǎn)新品獎(jiǎng)、航空科技進(jìn)步獎(jiǎng)等獎(jiǎng)勵(lì)。在航空、航天、兵器、船舶、通訊、鐵路、電力、電子、軌道交通、新能源、煤炭安全等軍用、民用領(lǐng)域得到廣泛應(yīng)用,并與國內(nèi)外知名高科技企業(yè)建立了良好的戰(zhàn)略合作伙伴關(guān)系和共贏模式。產(chǎn)品出口美國、歐洲、澳大利亞、韓國等30多個(gè)國家和地區(qū),在中國市場被譽(yù)為“電子元件領(lǐng)軍廠商”和進(jìn)入全球供應(yīng)鏈的軍工企業(yè)。
????? 公司為行業(yè)標(biāo)準(zhǔn)制定者,在國軍標(biāo)、航標(biāo)和總裝領(lǐng)域已有200余項(xiàng)標(biāo)準(zhǔn)獲得批準(zhǔn)并發(fā)布。公司先后建立了具有國際先進(jìn)標(biāo)準(zhǔn)水平的5條國軍標(biāo)生產(chǎn)線。公司通過武器裝備質(zhì)量體系認(rèn)證、ISO9001(2000)質(zhì)量體系認(rèn)證、AS9100國際航空航天質(zhì)量管理體系認(rèn)證;代表性產(chǎn)品通過UL、CUL、CE、TUV、CB等安規(guī)認(rèn)證;
????? 擁有美國UL目擊實(shí)驗(yàn)室和殲十飛機(jī)電子元器件篩選檢驗(yàn)站,同時(shí)建立了國內(nèi)企業(yè)首家電連接器DPA(破壞性物理分析)試驗(yàn)室以及RoHS檢測試驗(yàn)室。試驗(yàn)檢測中心被評定為國家和國防實(shí)驗(yàn)室。公司建立了質(zhì)量管理信息平臺(tái),引入和使用SPC、精益六西格瑪?shù)认冗M(jìn)的管理工具,使公司的質(zhì)量管理工作更加科學(xué)。同時(shí),ERP、OA、PDM三項(xiàng)技術(shù)深入推進(jìn),構(gòu)建公司整體信息網(wǎng)絡(luò)系統(tǒng)。
????? 公司踐行“航空報(bào)國、強(qiáng)軍富民”宗旨;秉承“誠信、廉潔、創(chuàng)新”為核心的中航光電特色文化,傾力打造獨(dú)具個(gè)性、充滿活力、富有價(jià)值、深受客戶歡迎的持續(xù)健康發(fā)展的全球化卓越企業(yè)。
二、礦機(jī)提升機(jī)的學(xué)習(xí)
(1)提升機(jī)的分類及工作原理
纏繞式提升機(jī)
單繩纏繞式提升機(jī) 根據(jù)卷筒數(shù)目可分為單卷筒和雙卷筒兩種:①單卷筒提升機(jī),一般作單鉤提升。鋼絲繩的一端固定在卷筒上,另一端繞過天輪與提升容器相連;卷筒轉(zhuǎn)動(dòng)時(shí),鋼絲繩向卷筒上纏繞或放出,帶動(dòng)提升容器升降。②雙卷筒提升機(jī),作雙鉤提升(圖1)。兩根鋼絲繩各固定在一個(gè)卷筒上,分別從卷筒上、下方引出,卷筒轉(zhuǎn)動(dòng)時(shí),一個(gè)提升容器上升,另一個(gè)容器下降。纏繞式提升機(jī)按卷筒的外形又分為等直徑提升機(jī)和變直徑提升機(jī)兩種。等直徑卷筒的結(jié)構(gòu)簡單,制造容易,價(jià)格低,得到普遍應(yīng)用。深井提升時(shí),由于兩側(cè)鋼絲繩長度變化大,力矩很不平衡。早期采用變直徑提升機(jī)(圓柱圓錐形卷筒),現(xiàn)多采用尾繩平衡。
纏繞式提升機(jī)工作原理
纏繞式提升機(jī)是利用鋼絲繩在滾筒上的纏繞和放出,實(shí)現(xiàn)容器的提升和下放。鋼絲繩的一端固定在滾筒上,另一端繞過天輪與提升容器連接,當(dāng)滾筒由電動(dòng)機(jī)拖動(dòng)以不同的方向轉(zhuǎn)動(dòng)時(shí),鋼絲繩或在滾筒上纏繞或放出,以帶動(dòng)提升容器。
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,鋼絲繩在兩卷筒上的纏繞方向相反。
摩擦式提升機(jī)
1938年,瑞典的ASEA公司在拉維爾(Laver)礦安裝了一臺(tái)直徑1.96m雙繩摩擦式提升機(jī)。1947年德國G.H.H.公司在漢諾威
礦安裝了一臺(tái)四繩摩擦式提升機(jī)。多繩摩擦式提升機(jī)具有安全性高、鋼絲繩直徑細(xì)、主導(dǎo)輪直徑小、設(shè)備重量輕、耗電少、價(jià)格便宜等優(yōu)點(diǎn),發(fā)展很快。除用于深立井提升外,還可用于淺立井和斜井提升。鋼絲繩搭放在提升機(jī)的主導(dǎo)輪(摩擦輪)上,兩端懸掛提升容器或一端掛平衡重(錘)。運(yùn)轉(zhuǎn)時(shí),借主導(dǎo)輪的摩擦襯墊與鋼絲繩間的摩擦力,帶動(dòng)鋼絲繩完成容器的升降。鋼絲繩一般為2~10根。 礦井提升機(jī)
井塔式提升機(jī) 機(jī)房設(shè)在井塔頂層,與井塔合成一體,節(jié)省場地;鋼絲繩不暴露在露天,不受雨雪的侵蝕,但井塔的重量大,基建時(shí)間長,造價(jià)高,并不宜用于地震區(qū)。
摩擦式提升機(jī)的工作原理
摩擦式提升機(jī)的工作原理是利用摩擦傳遞動(dòng)力。鋼絲繩搭放在摩擦輪的摩擦襯墊上,提升容器懸掛在鋼絲繩的兩端,在容器底部還懸掛平衡鋼絲繩。提升機(jī)工作時(shí)拉緊的鋼絲繩以一定的正壓力緊壓在摩擦襯墊之間便產(chǎn)生摩擦力。在這種摩擦力的作用下,鋼絲繩便跟隨摩擦輪一起運(yùn)動(dòng),從而實(shí)現(xiàn)容器的提升或下放。
(2)提升機(jī)的適用場合
礦用提升機(jī)是一種大型提升機(jī)械設(shè)備。由電機(jī)帶動(dòng)機(jī)械設(shè)備,以帶動(dòng)鋼絲繩從而帶動(dòng)容器在井筒中升降,完成輸送任務(wù)。礦井提升機(jī)是由原始的提水工具逐步發(fā)展演變而來?,F(xiàn)代的礦井提升機(jī)提升量大,速度高,安全性高,已發(fā)展成為電子計(jì)算機(jī)控制的全自動(dòng)重型礦山機(jī)械。
(3)提升機(jī)的規(guī)格型號
斗式提升機(jī)的型號有HL(TH)型、PL(NE)型、D(GTD)型等,其規(guī)格以料斗寬度表示,HL型有300、500等規(guī)格,PL型有250、350、450等規(guī)格。斗式提升機(jī)是水泥廠最常用的垂直輸送機(jī),通常用以提升塊、粒狀物料以及粉狀物料,由于鏈條,膠帶拉力限制,提升高度一般不超過30米。近年來生產(chǎn)的新型斗式提升機(jī)TH型、NE型、GTD型輸送能力都超過了100噸/小時(shí);提升高度超過70米;尤其是鋼絲繩芯膠帶斗式提升機(jī)(GTD型)輸送能力達(dá)到1600噸/小時(shí)以上,提升高度超過90米。
(4)提升機(jī)的參數(shù)
1、卷筒寬度和直徑
卷筒直徑:提升機(jī)卷筒上第一層鋼絲繩中心到卷筒中心距離的2倍。
絞車卷筒的直徑為:卷筒纏繩表面到卷筒中心距離的2倍。
二者概念有差別,相差1根鋼絲繩的直徑。
卷筒寬度:卷筒兩個(gè)擋繩板內(nèi)側(cè)直間的距離。
卷筒直徑和寬度決定了卷筒使用鋼絲繩的最大直徑和容繩量。
2、兩卷筒中心距離
雙卷筒提升機(jī):活動(dòng)卷筒與固定卷筒中心之間的距離。
該參數(shù)在計(jì)算繩偏角時(shí)要用到。
3、最大靜張力和最大靜張力差
鋼絲繩的張力,也就是鋼絲繩的拉力。在單鉤提升時(shí),滾筒上只有一根鋼絲繩,其拉力主要由提升容器、鋼絲繩、提升載荷的重力構(gòu)成。拉力最大值在天輪的切點(diǎn)處,載荷越大、井筒越深、容器重量越大鋼絲繩的拉力就越大。最大靜張力是針對提升機(jī)而言的,是強(qiáng)度允許的,滾筒上最大的拉力值。
4、鋼絲繩的速度與直徑
繩速:單位時(shí)間內(nèi)鋼絲繩在卷筒上纏繞的長度或通過摩擦輪的長度。 有最外層繩速、最內(nèi)層繩速、平均繩速等概念。一般是指平均繩速。
鋼絲繩直徑:允許纏繞的最大鋼絲繩直徑與卷筒直徑有關(guān)。
5、提升高度、容繩量
提升高度和斜長:提升容器在兩終端起停位置處,允許運(yùn)行的最大距離。
容繩量:按照規(guī)定,卷筒上允許纏繞的鋼絲繩的最大長度。
(5)主要部件及功能
1、主軸裝置
主軸裝置的作用及工作原理
主軸裝置是單繩纏繞式礦井提升機(jī)的主要工作部件,它的主要作用:纏繞提升鋼絲繩;承受各種載荷(包括固定載荷和工作載荷);承受各種緊急情況下所造成的非正常載荷,在非正常載荷的作用下,主軸裝置各部分不應(yīng)有的殘余應(yīng)力;雙筒提升機(jī),調(diào)節(jié)鋼絲繩的長度。
主軸裝置的工作原理:鋼絲繩的一端用壓繩板固定在卷筒的輻板上,另一端經(jīng)卷筒的纏繞后,繞過井架天輪懸掛提升容器。這樣,利用主軸的旋轉(zhuǎn)方式的不同,將鋼絲繩纏繞或松開,以完成提升容器的上升或下降。
出繩方式:單筒提升機(jī)單鉤提升時(shí)為上出繩,做雙鉤使用時(shí)右側(cè)為上出繩,左側(cè)為下出繩(反裝設(shè)備除外),雙筒提升機(jī),固定滾筒為上出繩,游動(dòng)滾筒為下出繩,雙筒提升機(jī)的排繩應(yīng)按同時(shí)同向纏繞為宜,不允許同時(shí)向兩個(gè)卷筒的中部或兩側(cè)移動(dòng),即當(dāng)提升鋼絲繩的纏繞層數(shù)在1.25~2.25 層時(shí),為避免提升過程中兩卷筒的鋼絲繩過分集中在主軸中部,使主軸受力狀態(tài)惡化,則使用靠游動(dòng)卷筒一側(cè)的出繩孔,其余情況則使用靠外側(cè)(主軸驅(qū)動(dòng)端)的出繩孔,游動(dòng)卷筒一般使用靠外側(cè)(主軸非驅(qū)動(dòng)端)的出繩孔。
主軸裝置的結(jié)構(gòu)
單筒提升機(jī)的結(jié)構(gòu)
單筒提升機(jī)的主軸裝置(如圖5)主要是由主軸、軸承座、滾筒、固定右支輪、固定左支輪、軸承、傳動(dòng)箱、軸承座底架等組成。其中固定右支輪與主軸為無鍵過盈連接,與滾筒采用鉸制孔螺栓連接。固定左支輪通過軸瓦滑裝在主軸上,與滾筒采用鉸制孔螺栓連接。
主軸是主軸裝置的主要零件之一,它承受了整個(gè)主軸裝置的自重、外載荷和傳遞全部扭矩,用中碳鋼鍛造而成。
滾筒采用Q345 板的焊接式結(jié)構(gòu),并經(jīng)高溫退火處理。主要由卷筒皮、制動(dòng)盤、擋繩板、輪輻、加強(qiáng)環(huán)等組成,根據(jù)客戶的現(xiàn)場實(shí)際需求,我公司卷筒可以加工成整體焊接式、兩剖分式和四剖分式,上述的結(jié)構(gòu)形式又可以分為制動(dòng)盤焊接式和制動(dòng)盤可拆卸式兩種。
主軸承座是承受整個(gè)主軸裝置自重和鋼絲繩上全部載荷的支撐部件,軸承采用雙列調(diào)心滾子軸承,這種軸承調(diào)心性能好,承載能力大,抗沖擊能力強(qiáng),同時(shí)也能承受少量的軸向載荷,使用壽命長、效率高、維護(hù)方便、對安裝誤差和主軸的繞度要求較低
雙筒提升機(jī)的結(jié)構(gòu)
雙筒提升機(jī)的主軸裝置(如圖6)主要是由主軸、軸承座、固定滾筒、游動(dòng)滾筒、固定右支輪、游動(dòng)支輪、固定左支輪、軸承、調(diào)繩離合器、傳動(dòng)箱、軸承座底架等組成。其中固定右支輪與主軸為無鍵過盈連接,與固定滾筒采用鉸制孔螺栓連接。固定左支輪通過軸瓦滑裝在主軸上,與固定滾筒采用鉸制孔螺栓連接。游動(dòng)支輪通過合金軸瓦與主軸滑動(dòng)連接,與游動(dòng)滾筒采用鉸制孔螺栓連接。
主軸是主軸裝置的主要零件之一,它承受了整個(gè)主軸裝置的自重、外載荷和傳遞全部扭矩,用中碳鋼鍛造而成。
滾筒采用Q345 板的焊接式結(jié)構(gòu),并經(jīng)高溫退火處理。主要由卷筒皮、制動(dòng)盤、擋繩板、輪輻、加強(qiáng)環(huán)及定位環(huán)等組成,根據(jù)客戶的現(xiàn)場實(shí)際需求,我公司卷筒可以加工成整體焊接式、兩剖分式和四剖分式,上述的結(jié)構(gòu)形式又可以分為制動(dòng)盤焊接式和制動(dòng)盤可拆卸式兩種。
主軸承座是承受整個(gè)主軸裝置自重和鋼絲繩上全部載荷的支撐部件,軸承采用雙列調(diào)心滾子軸承,這種軸承調(diào)心性能好,承載能力大,抗沖擊能力強(qiáng),同時(shí)也能承受少量的軸向載荷,使用壽命長、效率高、維護(hù)方便、對安裝誤差和主軸的繞度要求較低。
2、調(diào)繩離合器
調(diào)繩離合器主要用于解決多水平提升問題,即當(dāng)鋼絲繩伸長時(shí),調(diào)節(jié)鋼絲繩相對長度達(dá)到雙容器的相對準(zhǔn)確停車位置,我公司的調(diào)繩離合器為徑向齒塊式調(diào)繩離合器,主要有兩種:液壓式徑向齒塊調(diào)繩離合器和手動(dòng)式徑向齒塊調(diào)
繩離合器
手動(dòng)式徑向齒塊調(diào)繩離合器
手動(dòng)齒塊式調(diào)繩離合器(如圖7)主要由調(diào)繩內(nèi)齒、輪轂、移動(dòng)轂、離開板、螺旋套、齒塊體、手把、連板、蓋板、銷軸等組成。機(jī)器正常工作時(shí),齒塊與調(diào)繩內(nèi)齒處于嚙合狀態(tài)傳遞轉(zhuǎn)矩。需調(diào)繩時(shí),首先將頂緊螺旋套的緊固螺栓卸下,并用停止裝置將游動(dòng)滾筒鎖住,然后旋轉(zhuǎn)手把,帶動(dòng)螺旋套連接移動(dòng)轂做軸向位移,使其連板推動(dòng)齒塊體做垂直運(yùn)動(dòng),脫離固定在游動(dòng)卷筒上的調(diào)繩內(nèi)齒,達(dá)到離開目的。當(dāng)齒塊體與調(diào)繩內(nèi)齒脫開時(shí),轉(zhuǎn)動(dòng)固定卷筒,即可調(diào)繩。
調(diào)繩結(jié)束后,應(yīng)用手把反向旋轉(zhuǎn)螺旋套,推動(dòng)移動(dòng)轂,使兩齒塊與調(diào)繩內(nèi)齒緊密嚙合,然后用緊固螺栓頂緊螺旋套并用螺母鎖緊,卸下停止裝置。設(shè)備方可正常運(yùn)轉(zhuǎn)。此種調(diào)繩離合器結(jié)構(gòu)簡單,調(diào)繩方便,安全可靠。
液壓式徑向齒塊調(diào)繩離合器
液壓式徑向齒塊調(diào)繩離合器(如圖8)由輪轂、移動(dòng)轂、撥動(dòng)環(huán)、齒塊、內(nèi)齒圈、調(diào)繩油缸、聯(lián)鎖閥和行程開關(guān)等部分組成。該結(jié)構(gòu)可滿足調(diào)繩過程中安全、精確、快速、可靠。
液壓式徑向齒塊調(diào)繩離合器的工作原理:
(a)機(jī)械正常工作階段 此時(shí)齒塊和調(diào)繩內(nèi)齒處于嚙合狀態(tài),液壓缸的合上腔和離開腔通過液壓站上的電磁閥處于回油狀態(tài),聯(lián)鎖閥的柱銷鎖入調(diào)繩油缸活塞的凹槽內(nèi),機(jī)械正常運(yùn)行。
(b)調(diào)繩準(zhǔn)備階段 將游動(dòng)滾筒用停止裝置鎖住,撥動(dòng)操縱臺(tái)上調(diào)繩轉(zhuǎn)換開關(guān)到調(diào)繩位置,安全電磁閥斷電,使機(jī)械處于安全制動(dòng)狀態(tài)。啟動(dòng)液壓站(此時(shí)機(jī)器處于安全制動(dòng)狀態(tài)),高壓油即可通過調(diào)繩電磁閥進(jìn)入聯(lián)鎖閥,將聯(lián)鎖閥的柱銷從調(diào)繩油缸活塞的凹槽中移出,并且液壓油進(jìn)入調(diào)繩液壓缸的離開腔,推動(dòng)液壓缸活塞外移,使齒塊與調(diào)繩內(nèi)齒脫離嚙合,游動(dòng)卷筒與主軸連接脫開。
(c)調(diào)繩操作階段 調(diào)繩油缸打開到位之后,碰到行程開關(guān),此時(shí)固定卷筒解除安全制動(dòng),游動(dòng)卷筒仍為安全制動(dòng)。起動(dòng)設(shè)備主電機(jī)使固定卷筒慢速運(yùn)轉(zhuǎn),調(diào)節(jié)鋼絲繩長度或更換提升水平,實(shí)現(xiàn)調(diào)繩的目的。
(d)恢復(fù)工作階段 調(diào)繩完畢后,恢復(fù)固定卷筒的安全制動(dòng),然后將調(diào)繩電磁閥斷電,液壓缸的高壓油即回油箱。然后使調(diào)繩電磁閥的另一端得電,高壓油即可進(jìn)入液壓缸的合上腔,驅(qū)動(dòng)液壓缸活塞向里移動(dòng),使齒塊與調(diào)繩內(nèi)齒重新嚙合。同時(shí)活塞桿碰壓行程開關(guān),操縱臺(tái)上的指示燈顯示出“合上”的信號后,方可將調(diào)繩電磁閥斷電,并復(fù)位調(diào)繩轉(zhuǎn)換開關(guān)。電磁閥處于回油位置,然后將停止裝置卸下。至此,調(diào)繩操作全部結(jié)束,機(jī)器恢復(fù)正常的工作制動(dòng)狀態(tài)。
(e)調(diào)繩安全聯(lián)鎖環(huán)節(jié) 在調(diào)繩操作過程中,如果離合器萬一偶然地從原來的離開位置向合上位置移動(dòng)時(shí),行程開關(guān)即動(dòng)作,固定卷筒立即安全制動(dòng),避免打齒事故發(fā)生。確保調(diào)繩全過程的安全。
3、襯塊
襯塊的作用:使鋼絲繩不發(fā)生過多變形;使鋼絲繩有規(guī)則的排列,減少鋼絲繩的磨損。我公司的襯塊主要有兩種:塑襯和木襯。
木襯的厚度不得小于兩倍的鋼絲繩直徑,通常寬度在100mm 左右,選用柞木、水曲柳、或榆木制作,裝配時(shí)應(yīng)保證使其與滾筒接觸良好,否則,就會(huì)影響到卷筒的應(yīng)力分布,木襯在磨損后應(yīng)及時(shí)更換。
塑襯相對于木襯具有以下優(yōu)點(diǎn):耐磨性好,使用壽命是木襯的3 倍以上;許用壓應(yīng)力大,抗壓強(qiáng)度比木襯高7 倍以上;抗干燥、不吸水、耐潮濕性好,不會(huì)出現(xiàn)干裂和腐爛現(xiàn)象;繩槽排列整齊,可以降低鋼絲繩在纏繞運(yùn)行中的咬繩程度。從而提高鋼絲繩的使用壽命。
4、盤型制動(dòng)器
概述
盤型制動(dòng)器是通過碟形彈簧的彈力使閘瓦沿軸向從兩側(cè)壓向制動(dòng)盤產(chǎn)生制動(dòng)力,靠油壓壓縮彈簧帶動(dòng)閘瓦反向移動(dòng)解除制動(dòng)力,由于盤型制動(dòng)器是軸向產(chǎn)生制動(dòng)力,為防止制動(dòng)盤的變形和主軸產(chǎn)生軸向力,盤型制動(dòng)器都是成對使用的,每一對為一副盤型制動(dòng)器。
提升機(jī)的制動(dòng)系統(tǒng)是由盤型制動(dòng)器、液壓站、管路系統(tǒng)配套組成。作提升機(jī)的工作制動(dòng)和安全制動(dòng)之用。其制動(dòng)力大小、使用維護(hù)、制動(dòng)力調(diào)整對整個(gè)提升系統(tǒng)安全運(yùn)行都具有重大的影響,因此安裝、使用單位必須予以重視,確保運(yùn)行安全。
盤型制動(dòng)器具有以下特點(diǎn):
(1)制動(dòng)力矩具有良好的可調(diào)性;
(2)慣性小,動(dòng)作快,靈敏度高;
(3)可靠性高;
(4)通用性好,不同的礦井提升機(jī)可配不同數(shù)量相同型號的盤型制動(dòng)器;
(5)結(jié)構(gòu)簡單、維修調(diào)整方便。
結(jié)構(gòu)特征及工作原理
1、型號規(guī)格
根據(jù)盤型制動(dòng)器中盤型閘的正壓力不同,可將盤型閘分為32KN、40KN、63KN、80KN、100KN、120KN等不同規(guī)格。對于不同規(guī)格的盤型閘其工作原理是相同的。設(shè)計(jì)時(shí)可根據(jù)提升機(jī)所需的制動(dòng)力矩的大小進(jìn)行選用和配置
2、結(jié)構(gòu)特征
盤型制動(dòng)器(如圖9)主要是由盤型閘、支架、螺栓、油管和油管接頭等組成。盤型閘由雙頭螺栓成對的安裝在支架上。每個(gè)支架上可以安裝一對或多對盤型閘,盤型閘的數(shù)量和型號可根據(jù)提升機(jī)所需制動(dòng)力的大小確定。盤型閘(如圖10)是盤型制動(dòng)器的主要工作部件,以中低壓(≤6.3MPa)為例,盤型閘主要是由支座、閘瓦體、閘瓦、擋鐵、活塞、油缸、調(diào)整螺母、配油盤、緊固螺栓、導(dǎo)向鍵及密封圈等零部件組成。
3、工作原理
盤型制動(dòng)器是制動(dòng)系統(tǒng)的執(zhí)行機(jī)構(gòu),它在蝶形彈簧的作用下對制動(dòng)盤直接產(chǎn)生正壓力,并通過制動(dòng)盤和閘瓦的摩擦力形成所需的制動(dòng)力矩,完成礦井提升機(jī)的工作制動(dòng)和安全制動(dòng)。
5、深度指示器
結(jié)構(gòu)及工作原理
深度指示器主要是由箱體、齒輪、傘齒輪、絲杠、光杠、框架、支架、絲母、行程開關(guān)、指針及指示板等零件組成(如附圖13)。
提升機(jī)主軸的旋轉(zhuǎn)運(yùn)動(dòng)由傳動(dòng)裝置傳遞給深度指示器,經(jīng)過齒輪組傳動(dòng)給絲杠,使兩根垂直絲杠以互為相反的方向旋轉(zhuǎn)。當(dāng)絲杠旋轉(zhuǎn)時(shí),帶有指針的兩個(gè)梯形螺母也以互為相反的方向移動(dòng),即一個(gè)向上,一個(gè)向下。而絲杠的轉(zhuǎn)數(shù)與主軸轉(zhuǎn)數(shù)成正比,則螺母上指針在指示板上的位置也就與提升容器在井筒中的位置相對應(yīng),因此通過指針便能準(zhǔn)確地指出容器在井筒中的位置。深度指示器的光杠上下兩端各裝有減速和過卷行程開關(guān)。當(dāng)提升容器到達(dá)減速和過卷位置時(shí),絲母上的碰塊使行程開關(guān)動(dòng)作,發(fā)出信號。各行程開關(guān)的位置可根據(jù)實(shí)際需要進(jìn)行調(diào)整。
6、天輪裝置
天輪裝置主要用于單繩纏繞式提升機(jī),安裝在井架上,用來改變鋼絲繩的方向和根據(jù)提升系統(tǒng)要求滿足提升容器中心距,是提升機(jī)的主要承力件之一;其的公稱直徑與卷筒的公稱直徑一致,繩槽的大小與鋼絲繩的直徑有關(guān),天輪的數(shù)量可根據(jù)滾筒的數(shù)量來確定。
三、學(xué)習(xí)有關(guān)畢業(yè)設(shè)計(jì)的相關(guān)知識(shí)
內(nèi)裝式提升機(jī)國內(nèi)外發(fā)展?fàn)顩r及其優(yōu)點(diǎn)
由于礦用提升機(jī)在運(yùn)輸人員和煤礦上具有很重要的作用,人們開始追究提升機(jī)不占空間,內(nèi)裝式提升機(jī)就應(yīng)運(yùn)而生。在國內(nèi),內(nèi)裝式提升機(jī)和國外的相比還有很大的差距,國內(nèi)的裝式提升機(jī)還處于初期,只是把電動(dòng)機(jī)和一些外在的裝置放在了滾筒內(nèi)部,而國外的研究則比較深入,他們直接把滾筒做成轉(zhuǎn)子,作為電動(dòng)機(jī)的一部分,省去了聯(lián)軸器、減速器這些設(shè)備。在某種意義上內(nèi)裝式提升機(jī)在節(jié)約空間,減少能耗等方面有著突出的優(yōu)點(diǎn)。
15
XXXXXXX
XXXX設(shè)計(jì)(XXX)開題報(bào)告
題目名稱
礦用提升機(jī)的整體設(shè)計(jì)
學(xué)生姓名
專業(yè)班級
學(xué)號
一、 選題的目的和意義:
礦用提升機(jī)是一種大型提升機(jī)械設(shè)備。由電機(jī)帶動(dòng)機(jī)械設(shè)備,以帶動(dòng)鋼絲繩從而帶動(dòng)容器在井筒中升降,完成輸送任務(wù)。礦井提升機(jī)是由原始的提水工具逐步發(fā)展演變而來?,F(xiàn)代的礦井提升機(jī)提升量大,速度高,安全性高,已發(fā)展成為電子計(jì)算機(jī)控制的全自動(dòng)重型礦山機(jī)械。礦井提升機(jī)與壓氣,通風(fēng)和排水設(shè)備組成礦井四大固定設(shè)備,是一套復(fù)雜的機(jī)械------電氣排組。所以合理的選用礦井提升機(jī)具有很大的意義。礦井提升機(jī)的工作特點(diǎn)是在一定的距離內(nèi),以較高的速度往復(fù)運(yùn)行。為了保證工作效率和安全可靠,礦井提升機(jī)應(yīng)具有良好的控制設(shè)備和完善的保護(hù)裝置。熟悉礦井提升機(jī)的性能、結(jié)構(gòu)和動(dòng)作原理,提高安裝質(zhì)量,合理使用設(shè)備,加強(qiáng)設(shè)備維護(hù),對于確保提升工作高效率和安全可靠,防止和杜絕故障事故的發(fā)生,具有重大意義。礦井提升機(jī)對安全性、可靠性和調(diào)速性能的特殊要求,使得提升機(jī)電控系統(tǒng)的技術(shù)水平在一定程度上代表一個(gè)廠或國家的傳動(dòng)控制技術(shù)水平。
從個(gè)人角度來說,想借此機(jī)會(huì)把機(jī)械制造與設(shè)計(jì)好好學(xué)習(xí)一下,從理論到實(shí)踐的過渡,為以后自己參加工作奠定一些基礎(chǔ),有利于以后自己的設(shè)計(jì)生涯。
二、 國內(nèi)外研究綜述:
近三十年來,國外提升機(jī)機(jī)械部分和電氣部分都得到了飛速的發(fā)展,而且兩者相互促進(jìn),相互提高。起初的提升機(jī)是電動(dòng)機(jī)通過減速器傳動(dòng)卷筒的系統(tǒng),后來出現(xiàn)了直流慢速電動(dòng)機(jī)和直流電動(dòng)機(jī)懸臂安裝直接傳動(dòng)的提升機(jī)。上世紀(jì)七十年代西門子發(fā)明矢量控制的交一直一交變頻原理后,標(biāo)志著用同步電動(dòng)機(jī)來代替直流電機(jī)實(shí)現(xiàn)調(diào)速的技術(shù)時(shí)代已經(jīng)到來。1981年第一臺(tái)用同步機(jī)懸臂傳動(dòng)的提升機(jī)在德國Monopol礦問世,1988年由MAVGHH和西門子合作制造的機(jī)電一體的提升機(jī)(習(xí)慣稱為內(nèi)裝電機(jī)式)在德國Romberg礦誕生了,這是世界上第一臺(tái)機(jī)械和電氣融合成一體的同步電機(jī)傳動(dòng)提升機(jī)。在提升機(jī)機(jī)械和電氣傳動(dòng)技術(shù)飛速發(fā)展的同時(shí),電子技術(shù)和計(jì)算機(jī)技術(shù)的發(fā)展,使提升機(jī)的電氣控制系統(tǒng)更是日新月異。早在上世紀(jì)七十年代,國外就將可編程控制器(PLC)應(yīng)用于提升機(jī)控制。上世紀(jì)八十年代初,計(jì)算機(jī)又被用于提升機(jī)的監(jiān)視和管理。計(jì)算機(jī)和PLC的應(yīng)用,使提升機(jī)自動(dòng)化水平、安全、可靠性都達(dá)到了一個(gè)新的高度,并提供了新的、現(xiàn)代化的管理、監(jiān)視手段。特別要強(qiáng)調(diào)的是,此時(shí)期在國外一著名的提升機(jī)制造公司,如西門子、ABB、ALSTHOM都利用新的技術(shù)和裝備,開發(fā)或完善了提升機(jī)的安全保護(hù)和監(jiān)控裝置,使安全保護(hù)性能又有了新的提高。
就在國外科學(xué)技術(shù)突飛猛進(jìn)發(fā)展的時(shí)候,我國提升機(jī)電控系統(tǒng)很長時(shí)間都處于落后的狀況。直到目前為止,我國正在服務(wù)的礦井提升機(jī)電控系統(tǒng)大多數(shù)還是轉(zhuǎn)子回路串金屬電阻的交流調(diào)速系統(tǒng),設(shè)備陳舊、技術(shù)落后。國產(chǎn)提升機(jī)安全性、可靠性差,在關(guān)鍵部位—上下兩井口減速區(qū)段沒有配套的有效的速度監(jiān)視裝置,就提升機(jī)控制技術(shù)而言,依然是陳舊的,和國外相比,我們存在很大的差距。
礦井提升系統(tǒng)的類型很多,按被提升對象分:主井提升、副井提升;按井筒的提升道角度分:豎井和斜井;按提升容器分:箕斗提升、籠提升、礦車提升;按提升類型分:單繩纏繞式和多繩摩擦式等。我國常用的礦用提升機(jī)主要是單繩纏繞式和多繩摩擦式。我國的礦井與世界上礦業(yè)較發(fā)達(dá)的國家相比,開采的井型較小、礦井提升高度較淺,煤礦用提升機(jī)較多,其他礦(如金屬礦、非金屬礦)則較少。因此在20世紀(jì)60年代開始單繩纏繞式礦井提升機(jī)采用較多。
20世紀(jì)80年代,我國從瑞典、西德等國引進(jìn)20多套晶閘管—直流電動(dòng)機(jī)控制系統(tǒng)。我國自己生產(chǎn)的晶閘管—直流電動(dòng)機(jī)控制系統(tǒng)應(yīng)用于20世紀(jì)90年代。這種控制系統(tǒng)的優(yōu)點(diǎn)是:體積小、重量輕、占地面積小;基礎(chǔ)省、安裝方便、建筑費(fèi)用低;無齒輪傳動(dòng)部分(不需要減速器)、總效率高、電能消耗少;單機(jī)容量大,適用范圍廣;調(diào)速平穩(wěn)、調(diào)速范圍廣、調(diào)速精度高;易于控制,能實(shí)現(xiàn)自動(dòng)化,安全可靠;節(jié)約電能。
礦井提升機(jī)對安全性、可靠性和調(diào)速性能的特殊要求,使得提升機(jī)電控系統(tǒng)的技術(shù)水平在一定程度上代表一個(gè)廠或國家的傳動(dòng)控制技術(shù)水平。比較國內(nèi)外礦用提升機(jī)系統(tǒng),具體來說國外礦井提升機(jī)在電控方面的應(yīng)用特點(diǎn)有以下幾個(gè)方面:
l)提升工藝過程微機(jī)控制
2)提升行程控制
3)提升過程監(jiān)視
4)安全回路
20世紀(jì)80年代西歐一些工業(yè)先進(jìn)國家將交流變頻調(diào)速技術(shù)應(yīng)用于提升機(jī),有代表性的是西門子公司和ABB公司。我國在20世紀(jì)90年代也引進(jìn)了交流變頻調(diào)速提升機(jī)控制系統(tǒng)。變頻調(diào)速方式類似于它勵(lì)直流電動(dòng)機(jī)取得很寬的調(diào)速范圍、很好的調(diào)速平滑性和有足夠硬度的機(jī)械特性,在提升機(jī)應(yīng)用中顯示了其獨(dú)特的優(yōu)勢。
三、畢業(yè)設(shè)計(jì)(論文)所用的主要技術(shù)與方法:
1、資料的方法:圖書館借閱相關(guān)的設(shè)計(jì)手冊、專業(yè)書刊。從網(wǎng)上查閱相關(guān)的論文、相關(guān)產(chǎn)品的技術(shù)參數(shù)等資料。
2、采用計(jì)算機(jī)輔助設(shè)計(jì)的辦法,掌握CAD、soldeworks或pro-E等軟件的使用方法。設(shè)計(jì)圖紙為電子版。
3、理論、強(qiáng)度計(jì)算、選型計(jì)算
四、主要參考文獻(xiàn)與資料獲得情況:
1《礦井提升機(jī)》 洛陽礦山機(jī)械研究所編 機(jī)械工業(yè)出版社出版
2《礦井提升機(jī)的計(jì)算和設(shè)計(jì)》 蘇聯(lián)布·勒·達(dá)維道夫著 煤炭工業(yè)出版社
3《礦井多繩提升機(jī)選型設(shè)計(jì)》 范家駿 編 煤炭工業(yè)出版社
4《礦井提升設(shè)備》 中國礦業(yè)學(xué)院 主編 煤炭工業(yè)出版社
5《機(jī)械設(shè)計(jì)課程設(shè)計(jì)》 路玉 何在洲 佟延偉 編 機(jī)械工業(yè)出版社
6《機(jī)械設(shè)計(jì)》 濮良貴 邵明剛 主編 高等教育出版社
五、 畢業(yè)設(shè)計(jì)(論文)進(jìn)度安排(按周說明):
4月9號到16號完成材料的收集,確定畢業(yè)論文的提綱
4月21日到4月30日確定相關(guān)設(shè)計(jì)方案,進(jìn)行結(jié)構(gòu)設(shè)計(jì)
5月1日到5月15日進(jìn)行結(jié)構(gòu)設(shè)計(jì)審查,修改設(shè)計(jì)圖紙
5月16日到5月30日設(shè)計(jì)圖紙基本完成,設(shè)計(jì)書編寫完成
六、指導(dǎo)教師審批意見:
指導(dǎo)教師: (簽名)
年 月 日
4
附錄
英文原文
Reflections regarding uncertainty of measurement, on the results of a Nordic fatigue test interlaboratory comparison
Magnus Holmgren, Thomas Svensson, Erland Johnson, Klas Johansson
Abstract
This paper presents the experiences of calculation and reporting uncertainty of measurement in fatigue testing. Six Nordic laboratories performed fatigue tests on steel specimens. The laboratories also reported their results concerning uncertainty of measurement and how they calculated it. The results show large differences in the way the uncertainties of measurement were calculated and reported. No laboratory included the most significant uncertainty source, bending stress (due to misalignment of the testing machine, “incorrect” specimens and/or incorrectly mounted specimens), when calculating the uncertainty of measurement. Several laboratories did not calculate the uncertainty of measurement in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [1].
Keyword: Uncertainty of measurement, Calculation, Report, Fatigue test, Laboratory intercomparison
Definitions :R Stress ratio Fmin/Fmax · F Force (nektons) · A and B Fatigue strength parameters · s and S Stress (megapascals) · N Number of cycles.
Introduction
The correct or best method of calculating and reporting uncertainty of measurement in testing has been the subject of discussion for many years. The issue became even more relevant in connection with the introduction of ISO standards, e.g. ISO17025 [2]. The discussion, as well as implementation of the uncertainty of measurement concept, has often been concentrated on which equation to use or on administrative handling of the issue. There has been less interest in the technical problem and how to handle uncertainty of measurement in the actual experimental situation, and how to learn from the uncertainty of measurement calculation when improving the experimental technique. One reason for this may be that the accreditation bodies have concentrated on the very existence of uncertainty of measurement calculations for an accredited test method, instead of on whether the calculations are performed in a sound technical way. The present investigation emphasizes the need for a more technical focus.
One testing area where it is difficult to do uncertainty of measurement calculations is fatigue testing. However, there is guidance on how to perform such calculations, e.g. in Refs. [3, 4]. To investigate how uncertainty of measurement calculations are performed for fatigue tests in real life, UTMIS (the Swedish fatigue network) started an interlaboratory comparison where one of the most essential parts was to calculate and report the uncertainty of measurement of a typical fatigue test that could have been ordered by a customer of the participating laboratories. For cost reasons, customers often ask for a limited number of test specimens but, at the same time, they request a lot of information about a large portion of the possible stress-life area [from few cycles (high stresses) to millions of cycles (low stresses) and even run-outs]. The way the calculation was made should also be reported. The outcome concerning the uncertainty of measurement from the project is reported in this article.
Participants
Six Nordic laboratories participated in the interlaboratory comparison: one industrial laboratory, two research institutes, two university laboratories and one laboratory in a consultancy company. Two of the laboratories are accredited for fatigue testing, and a third laboratory is accredited for other tests. Each participant was randomly assigned a number between 1 and 6, and this notification will be used in the rest of this paper.
Experimental procedure
The participants received information about the test specimens (without material data), together with instructions on the way to perform the test and how to report the results.
The instructions were that tests should be performed as constant load amplitude tests, with R=0.1 at three different stress levels, 460, 430 and 400 Map, with four specimens at each stress level, at a test frequency between 10 and 30 Hz, with a run-out limit at cycles and in a normal laboratory climate ( and relative humidity). This was considered as a typical customer ordered test.
The test results were to be used to calculate estimates of the two fatigue strength parameters, A and B, according to linear regression of the logs and long variables, i.e.. The reported result should include both the estimated parameters A and B and the uncertainties in them due to measurement errors. The report should also include the considerations and calculations behind the results, especially those concerning uncertainty of measurement.
Several properties were to be reported for each specimen. The most important one was the number of cycles until fracture or if the specimen was a run-out (i.e. survived for cycles).
The tests were to be performed in accordance with ASTM E-466–96 [5] and ISO5725-2 [6]. ASTM E-466-96 does not take uncertainty of measurement into account;
However, ASTM E-466-96 mentions that the bending stress introduced owing to misalignment must not exceed 5% of the greater of the range, maximum or minimum stresses. There are also requirements for the accuracy of the dimensional measurement of the test specimen.
All participants used hydraulic testing machines. The test specimens were made of steel (yield stress 375–390 Map, and tensile strength 670–690 Map, tabulated values). The test specimens were distributed to the participants by the organizer.
Results
The primary laboratory results that should be compared are the estimated Whaler curves. In order to present all results in the same way, the organizer transformed some of the results. The Whaler curves reported by the participants are shown in Fig. 1.
It can be seen that there are considerable differences between laboratories. An approximate statistical test shows a significant laboratory effect. Material scatter alone cannot explain the differences in the Whaler curves.
In order to investigate if the laboratory effect was solely caused by the modeling uncertainty, we estimated new parameters from the raw data with a common algorithm. We then chose to use only the failed specimens and to make the minimization in the logarithmic life direction. The results are shown in Fig. 2. A formal statistical significance test was then made, and the result of such a test shows that the differences between the laboratories shown in Fig. 1 could be attributed only to modeling.
Uncertainty of measurement calculations
One of the most important objectives with this investigation was to compare the observed differences between laboratory test results with their estimated uncertainties of measurement. The intention was to analyze the uncertainty analyses as such, and to compare them to the standard procedure recommended in the ISO guide: Guide to the Expression of Uncertainty in Measurement (GUM) [1].
The laboratories identified different sources of uncertainty and treated them in different ways. These sources are the load measurement, the load control, the superimposed bending stresses because of misalignment and the dimensional measurements. Implicitly, laboratory temperature and humidity, specimen temperature and corrosion effects are also considered. In addition, the results show a modeling effect. The different laboratory treatments of these sources are summarized in Table 1.
Specific comments on the different laboratories
All laboratories gave their laboratory temperature and humidity, but did not consider these values as sources of uncertainty, i.e. the influence of temperature and humidity was neglected. This conclusion is reasonable for steel in the temperature range and humidity range in question [7].
Laboratory 1. The uncertainty due to the applied stress was determined taking load cell and dimensional uncertainties into account. The mathematical evaluation was made in accordance with the GUM. Specimen temperature was measured, but was implicitly neglected. The modeling problem was mentioned, but not considered as an uncertainty source. Laboratory 2. The report contains no uncertainty evaluation. The uncertainties in the load cell and the micrometer are considered, but neglected with reference to the large material scatter. Specimen temperature was measured. Modeling problems are mentioned by a comment regarding the choice of load levels.
Laboratory 3. The report contains no uncertainty evaluation. However, the accuracy of the machine is given and the load was controlled during the tests to be within specified limits. The bending stresses were measured on one specimen, but their influence on the fatigue result was not taken into consideration. Laboratory 4. The uncertainties in the load cell and the dimensional measurements are considered in an evaluation of stress uncertainty. The method for the evaluation is not in accordance with the GUM method, but was performed by adding absolute errors. The bending stress influence and the control system deviations are considered, but not included in the uncertainty evaluation. The failure criterion is mentioned and regarded as negligible, and corrosion is mentioned as a possible source of uncertainty. Laboratory 5. Uncertainties in the load cell and the load control were considered, and the laboratory stated in the report that the evaluation of the load uncertainty was performed according to the CIPM method. Laboratory 6. No report was provided, but only experimental results and a Whaler curve estimate.
No laboratory reported the uncertainty in the estimated material properties, the Whaler parameters, but at most the uncertainty in the applied stress. The overall picture of the uncertainty considerations is that only uncertainty sources that are possible to estimate from calibration reports were taken into account in the final evaluation.
Fig. 1 All experimental results and estimated Whole curves from the different laboratories
Number of cycles to failure
One important source that several laboratories mentioned is the bending stresses induced by misalignment in the testing machine, incorrectly mounted test specimens or “incorrect” specimens. The amount of bending stress was also estimated in some cases, but its influence on the uncertainty in the final Whole curve was not investigated.
The results from this experimental investigation show that there are different ways of determining the Whole curve from the experimental result. One problem is the surviving specimens, the run-out results. Four laboratories used only the failed specimens’ results for the curve-fit, one laboratory neglected all results at the lowest level, and one laboratory included the run-outs in the estimation. Another problem is the mathematical procedure for estimating the curve. Common practice, and the recommendation in the ASTM standard, is that the curve should be estimated by minimizing the squared errors in log life, i.e. the statistical model is
, (1)
Where e is a random error, assumed to have constant variance, and where log stands for the logarithm with base 10. E can be interpreted as the combination of at least two types of errors: namely (1) a random error due to the scatter in the material properties, and (2) a measurement error due to uncertainties in the measurement procedures.
Fig. 2 All experimental results and estimated Whole curves using the common procedure
Number of cycles to failure
Table 1 Sources of uncertainty and laboratory treatment
C The laboratory report considers the source explicitly or implicitly, N the laboratory report neglects the source, A the laboratory report takes the source into account in the uncertainty of measurement calculation
Where e is a random error, assumed to have constant variance, and where log stands for the logarithm with base 10. E can be interpreted as the combination of at least two types of errors: namely (1) a random error due to the scatter in the material properties, and (2) a measurement error due to uncertainties in the measurement procedures. Stress was minimized, which led to a model discrepancy as discussed in the following.
Discussion
Experimental results
Most laboratories performed estimations of the Whaler curve parameters. Visual comparison of their estimated curves suggests differences, and a statistical test verified the conclusion that there is a statistically significant laboratory effect. A closer study of each participant’s procedure for determining the Whaler curve shows that the differences seem to be caused by different modeling of the curve.
Since the test was intended to simulate a customer ordered test, some specific problems occurred. First, the number of test specimens is limited and therefore one should be careful when drawing conclusions from the results, since the scatter is considerable in fatigue and the number of specimens are limited.
Another problem that occurred was that, since run-outs were wanted, two different failure criteria (failure mechanisms) were used to halt the test: fracture of the test specimen or cycles. In the latter case, the use of the equation may cause problems, see later.
The investigator then looked at whether any laboratory differences remained after excluding the model interpretation effects. This was accomplished in two ways:
Namely, firstly by direct comparison of the experimental fatigue lives obtained, and secondly by using the same estimating procedure on all data sets. This therefore tested whether any laboratory differences remained or not. The first comparison was done on the two higher load levels. For these, no statistically significant differences were found. The second comparison, which included the failures
On the lowest level, verified the result. Since the variation between laboratories is larger than the variation within a laboratory no statistically significant variation within a laboratory can be distinguished from the total
Variation in material.
The conclusion is that no systematic errors in measurements were detected, but different modeling techniques give significant differences in the results. This in fact indicates that when different fitting models are used different quantities are measured even though they have the same name. Before any agreement is reached about the way of reporting fatigue data, it is of utmost importance that the modeling procedure is clearly defined in the test report. It is very important for the laboratories’ customers to be aware of this fact and, when requesting a test, to ask for a preferred modeling procedure as well as to be aware of the modeling procedure used by the laboratory when using fatigue data in design.
Uncertainty evaluation
All laboratories made some considerations regarding the uncertainties of measurement. However, none of them evaluated uncertainties for the resulting Whole parameters, but only for the applied stress. However, none of the measurement uncertainties reported are unrealistic considering the factors taken into account, this is based inexperience. Since the specimens were destroyed during the tests it is not possible to separate the material variation from the repeatability. An estimate of the combined measurement uncertainty and the variation in material is
About 30% of the lifetime and the major contribution are from the material variation and therefore one conclusion is that the measurement uncertainty in this test could be neglected during this test. This is not true for all fatigue tests and it is therefore anyhow interesting to study how the participants treated measurement uncertainty.
Only one participant used the method recommended by the ISO guide GUM. This is surprising, since European accreditation authorities have recommended the GUM for several years. Among the uncertainty sources that were identified by the laboratories, only load cell measurement uncertainties and dimensional measurement uncertainties were taken into account. Important sources such as misalignment and load control were identified by some participants but were not included in the evaluation of stress uncertainty. Apparently only calibrated devices were considered for the overall uncertainty, and other sources, more difficult to evaluate, were excluded. No motivation for these exclusions can be found in the reports.
One participant rejected the uncertainty evaluation with reference to the large scatter in fatigue lives. Our overall conclusion from the laboratory comparisons, that there are no detectable systematic effects, may be seen as verification of this rejection, but it is questionable if this was an obvious result beforehand. In contrast, for instance, uncertainties due to misalignment are not obviously negligible in comparison with the material scatter, and should be considered in an uncertainty analysis.
This investigation, together with other observations [8, 9], shows problems with the introduction of the ISO17025 requirement for uncertainty of measurement statements. The reasons for this may be that the uncertainty of measurement discussion during recent years has concentrated very much on which equation to use and on administrative aspects, e.g. whether the uncertainty of measurement should always be reported directly in the report, or only when the customer requests it, etc., instead of on the ‘real’ technical issues. Hopefully, the introduction of the pragmatic ILAC-G17:2002, a document about the introduction of the concept of uncertainty of measurement in association with testing [10], will improve the situation.
Conclusions
The way to define, calculate, and interpret uncertainty of measurement and to use it in Whaler-curve determination is poorly understood among the participants, in spite of the fact that they consist of a group with significant experience
Of fatigue testing, and that some of them were also accredited for fatigue tests. An important overall tendency is that the laboratories only include uncertainty
Sources that are easily obtained, e.g. from calibrated gauges where calibration certificates exist.
中文翻譯
關(guān)于北歐的疲勞實(shí)驗(yàn)室的比較—測量結(jié)果不確定值的反映
摘要:這篇論文介紹了關(guān)于疲勞檢測的不確定性的計(jì)算和報(bào)告的實(shí)驗(yàn)。6個(gè)北歐實(shí)驗(yàn)室對鋼性元件進(jìn)行了疲勞實(shí)驗(yàn),他們也報(bào)告了疲勞測量不確定性的結(jié)果和計(jì)算方法。實(shí)驗(yàn)結(jié)果表明大量的測量不確定性結(jié)果是可以計(jì)算和報(bào)告的。沒有實(shí)驗(yàn)室包括最重要的不確定源,當(dāng)它們進(jìn)行不確定值的計(jì)算時(shí),有幾個(gè)實(shí)驗(yàn)室沒有計(jì)算符合從指導(dǎo)到結(jié)果的測量的不確定性值。
關(guān)鍵詞:測量,計(jì)算,不確定性報(bào)告,疲勞測試,聯(lián)合實(shí)驗(yàn)室
介紹:計(jì)算和報(bào)告測量的不確定性值的最好或者正確的方法一直是許多年來討論的問題,隨著ISO(例如ISO17025)的引進(jìn)這個(gè)問題更加突出。關(guān)于測量的不確定性值的討論和鑒定與這個(gè)問題息息相關(guān)。在發(fā)展實(shí)驗(yàn)技術(shù)的時(shí)候已經(jīng)有很少人對技術(shù)問題和在實(shí)驗(yàn)條件下如何處理測量的不確定性值和如何從測量的不確定性值可以學(xué)到什么感興趣了。這種現(xiàn)象可能的一個(gè)原因是合格的物體已經(jīng)集中在用精確的方法計(jì)算測量的不確定性值上,而不是集中在用這種方法是不是合理的問題上了。目前的方法集中在一種更加科學(xué)的方法上。
對測量的不確定性值計(jì)算比較困難的一個(gè)領(lǐng)域是疲勞測量。但是,對于這樣的計(jì)算有一個(gè)指導(dǎo),研究如何確定測量不確定性值的方法是研究現(xiàn)實(shí)生活中物體的疲勞檢測。瑞典疲勞網(wǎng)站開設(shè)了一家聯(lián)合實(shí)驗(yàn)室公司,它的最重要的一部分就是計(jì)算和報(bào)告重要疲勞實(shí)驗(yàn)的不確定性值,這些實(shí)驗(yàn)是由實(shí)驗(yàn)室的參與者進(jìn)行的。最重要的原因是顧客們索要有限個(gè)測量模型,同時(shí),他們也需要大量的信息。所用的計(jì)算方法也要報(bào)告,關(guān)于工程測量的不確定性值的結(jié)果也在這篇文章中報(bào)告。
六個(gè)北歐的實(shí)驗(yàn)室都參加了這個(gè)聯(lián)合實(shí)驗(yàn)室,一個(gè)工業(yè)實(shí)驗(yàn)室,兩個(gè)研究院,兩個(gè)大學(xué)實(shí)驗(yàn)室,一個(gè)咨詢公司實(shí)驗(yàn)室。其中兩個(gè)實(shí)驗(yàn)室研究疲勞實(shí)驗(yàn),第三個(gè)研究其他的實(shí)驗(yàn),每個(gè)參與者被隨意指派1—6的編號,這個(gè)報(bào)告被用在這篇文章的其他部分。
實(shí)驗(yàn)程序:
參與者收到了沒有數(shù)據(jù)的材料模型,及其如何進(jìn)行測量和如何報(bào)告結(jié)果的信息。要求是在固定載荷下進(jìn)行多次實(shí)驗(yàn),用半徑為1mm的在三種壓力(460,430,400MP)下,每種壓力下都進(jìn)行試驗(yàn)的4種模型,頻率在10---30Hz之間,在室溫下旋轉(zhuǎn)5百萬轉(zhuǎn)。這就是客戶要求的測量。
這種測量結(jié)果被用來計(jì)算兩個(gè)物體的疲勞增長的參數(shù),A和B,和由于測量錯(cuò)誤而引起的不確定性值,報(bào)告的結(jié)果應(yīng)該包括A和B的結(jié)果和這種不確定性值,在結(jié)果的后面尤其是這些不確定性值每個(gè)模型的這幾種特性都應(yīng)該報(bào)告。最重要的是模型達(dá)到疲勞時(shí)的周期數(shù),或者是模型報(bào)廢的周期數(shù)。做這個(gè)測量時(shí)ASTM E-466-96、ISO-5725-2.、ASTM E-466-96并沒有考慮到測量的不確定性值,由于誤差不能超過最大和最小值的范圍的百分之五,所以,ASTM-466-96參照彎曲壓力,對模型的測量也有一些精度要求。所有的參加者都用液壓疲勞機(jī),測量模型是由鋼制成的,它的表面的壓力范圍是375-390Mp,拉伸力壓強(qiáng)的范圍是670-690Mp.測量模型由組織者分發(fā)給參加者。
結(jié)果:
為了用同一種方法表示出所有的結(jié)果,初級實(shí)驗(yàn)結(jié)果應(yīng)該用Whole表格來進(jìn)行比較,參與者報(bào)告的Whole表格見圖1。它顯示了各實(shí)驗(yàn)室之間的顯著的差別。一個(gè)大概統(tǒng)計(jì)的實(shí)驗(yàn)結(jié)果表明了各實(shí)驗(yàn)室的顯著差別,分散的材料不能單獨(dú)解釋W(xué)hole表格的區(qū)別,為了研究各實(shí)驗(yàn)室的差別是否是因?yàn)槟P偷牟淮_定造成的,我們比較了由原始數(shù)據(jù)得出的新數(shù)據(jù),當(dāng)我們使用那些不合格的模型時(shí),對結(jié)果進(jìn)行對數(shù)運(yùn)算后,結(jié)果如2圖所示。以前的統(tǒng)計(jì)結(jié)果和這次的結(jié)果比較可得結(jié)果如圖1所示。
測量計(jì)算得不確定性
這個(gè)研究的重要過程之一就是比較各實(shí)驗(yàn)室之間的估計(jì)的測量不確定性的差別。目的就是分析測量的不確定性,參照ISO標(biāo)準(zhǔn)比較他們的制造水平,各實(shí)驗(yàn)室把不同的不確定性集中起來用不同的方法來處理。由于誤差和空間的測量,這些資源是固定的測量,確定的控制和可靠的彎曲應(yīng)力,而且,實(shí)驗(yàn)室內(nèi)的溫度和濕度,模型的溫度和腐蝕的影響也需要考慮。結(jié)果也表明了模型制造的效果。不同的實(shí)驗(yàn)室對這些材料的處理方法如圖1所示。
不同實(shí)驗(yàn)室的具體評論
所有的實(shí)驗(yàn)室都設(shè)定了室內(nèi)溫
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