鶴式(門式)起重機設(shè)計
鶴式(門式)起重機設(shè)計,鶴式,門式,起重機,設(shè)計
太原科技大學畢業(yè)設(shè)計說明書
第五章 起重機的穩(wěn)定性
起重機的穩(wěn)定性是指起重機在自重和外載荷的作用下抵抗翻到的能力,起重機的穩(wěn)定性,按兩種基本情況分別進行演算:工作時的穩(wěn)定性——載重穩(wěn)定性;非工作時的穩(wěn)定性——自重穩(wěn)定性。驗算時,防風裝置的作用不予考慮
臂架類起重機按以下步驟校核抗傾覆穩(wěn)定性:
(一) 確定起重機的組別
門座起重機屬于Ⅵ組
(二) 穩(wěn)定性校核時,應(yīng)按課本表13-3所列工況在最不利載荷組合條件下進行,若包括起重機自重的各項載荷對傾覆邊的力矩大于或等于0(即M≥0)則認為起重機是穩(wěn)定的,計算時規(guī)定起穩(wěn)定作用的力矩符號為正,使起重機傾覆的力矩符號為負。
(三) 傾覆邊的不確定
運行機構(gòu)只作非吊重位移的定點吊裝的起重機必須按上述的穩(wěn)定性校核規(guī)定的計算原則。對支撐多邊形車輪或支腿與地面接觸點連線的每條傾覆邊進行穩(wěn)定性校核。
臂架類起重機穩(wěn)定性栽種狀態(tài)的計算簡圖
式中:0.95,1.5—裝卸用門座起重機第Ⅰ工況的載荷系數(shù)
PG—起重機的自重載荷 750KN
PQ—最大起升載荷 80KN
Rmax—最大幅度 25mm
b—1/2軌距或基距,取其中較小者 b=1/2×12=6m
x0—最大幅度位置上起重機自重重心距回轉(zhuǎn)中心的距離,假定x0=0.5m
2有風動載荷工況
如圖所示,起重機在這種工況下較易翻倒的狀態(tài)是:臂架垂直于傾覆邊的軌道,并處于最大幅度位置,起吊額定重量,軌道前低后高,工作狀態(tài)最大風力沿臂架方向由后向前吹,貨物向外擺動Ⅱ角,并下降制動,這時起重機相對于傾覆邊受到由起重機自重載荷在平行軌面方向上的分力、風力、貨物起升載荷、貨物偏擺的水平載荷、貨物下降制動所引起的傾覆力矩和由起重機自重載荷在垂直軌面方向上的分力引起的復原力矩的作用。因而,這種工況下對傾覆邊的總力矩,按下式計算:
式中:
0.95,1.35—裝卸用門座起重機第Ⅱ工況的載荷系數(shù)
γ—軌面坡度角0○10’ =0.17○
h0—在最大幅度位置起重機自重重心距軌面的距離,h0=10m,
PwⅡ—工作狀態(tài)作用在起重機上的最大風力
h風Ⅱ—總鋒利PwⅡ的作用點到軌面的距離,h風Ⅱ=12m
h—臂架至軌面的距離 h=16m
P慣—貨物下降制動時所產(chǎn)生的慣性力,以PQ/g表示起升貨物質(zhì)量。V降(m/min)表示下降速度(一般等于起升速度,v降=v升)
t制表示制動時間(可暫取1s)則:
R’—起升繩偏斜后離傾覆邊的距離,可由幾何關(guān)系求得:
3突然卸載工況
這種工況對傾覆邊作用的總力矩
按下式計算:
?式中:
0.95,0.2—裝卸用門座起重機第Ⅲ工況載荷系數(shù)
4暴風襲擊下的工作狀態(tài)工況
對傾覆邊作用的總力矩
按下式計算
?
式中:
0.95,1.1—裝卸用門座起重機第Ⅳ工況載荷系數(shù)
—在最小幅度位置上起重機自重重心距回轉(zhuǎn)中心的距離,=1m
—作用在起重機上的非工作狀態(tài)最大總風力,=40.59kN
—總風力的作用點距軌面的距離,=22.5m
?
綜上所述:起重機在四種工況下均能滿足抗傾覆穩(wěn)定性要求,即整機穩(wěn)定性通過
第六章 選緩沖器
起重機一般必須裝設(shè)緩沖器,緩沖器的作用是減緩起重機在運行到終點擋上器或兩臺起重機相互碰撞的沖擊
1初選緩沖器型號
緩沖器行程S
?
式中
—大車碰撞速度,有限位開關(guān)。取=0.65
[amax]—最大減速度,一般情況下?[amax]<5m/s2,取[amax]=3m/s2
根據(jù)緩沖器行程S選用JHQ—A—3型聚氨酯緩沖器,其額定緩沖行程Sn=60mm,額定緩沖量En=628Nm極限緩沖力FⅠ=66kN
2緩沖器數(shù)目
根據(jù)緩沖器能量來確定緩沖器數(shù)目
緩沖能量Ew
?
則n取2
3實際緩沖行程最大緩沖力和最大減速度
第七章 起重機的防風抗滑安全性
防風抗滑安全性是指起重機在工作和非工作狀態(tài)下抵抗因風力作用而發(fā)生滑行的能力。為保證軌行時能安全可靠的工作,必須使起重機有足夠的防風抗滑安全性。
工作狀態(tài)下的防風抗滑安全性,通常用制動裝置加以保證,非工作狀態(tài)下的防風抗滑安全性,一般用防風夾規(guī)器、防風鐵鍥、錨定裝置來保證
1正常工作狀態(tài)
由運行機構(gòu)計算得
2非正常工作狀態(tài)
起重機受非工作狀態(tài)下的最大風力,沿著運行方向作用,不考慮制動器的防風抗滑作用(偏于安全)防風抗滑的驗算公式為:
?
式中:
—軌道最大坡度,=0.003
=19.8kN
=750kN
—不考慮附加阻力的運行阻力
—抗滑安全系數(shù),=1.2
故選擇YXZ系列防風鐵鍥
型號YXZ-500/80
推動器額定推力為:
P=80kN>21.51kN
中英文翻譯
履帶起重機市場發(fā)展現(xiàn)狀及最新技術(shù)分析
履帶起重機以其起重量大、作業(yè)空間大、帶載行走、接地比壓小等獨特的優(yōu)勢逐漸從眾多起重機中脫穎而出,成為工程建設(shè)中的佼佼者。隨著應(yīng)用廣度和深度的不斷加大,履帶起重機在結(jié)構(gòu)、傳動、控制等方面卻發(fā)生著變化,從而鞏固和提高了履帶起重機的整體水平,使產(chǎn)品不斷完善。
1.國內(nèi)履帶起重機市場現(xiàn)狀
目前,國內(nèi)市場的需求強勁,各行業(yè)的大型施工企業(yè)紛紛進口大型履帶起重機,搶占市場制高點。2002年中石化公司進口德馬格1250t履帶起重機,2006年上半年中石油公司又引進了利勃海爾1250t履帶起重機。國內(nèi)大型履帶起重機的進口已超過100臺,2003年和2004年進口的245臺和357臺產(chǎn)品中,800t以上的大型產(chǎn)品近5臺,750t近10臺,600t10余臺,400~500t30余臺。到2006年上半年底,國內(nèi)已引進M21000型907t、CC5800型800/1000噸級產(chǎn)品。
隨著大型履帶起重機市場需求量的不斷增長,對履帶起重機的性能、質(zhì)量、可靠性要求也越來越高。歐、美、日相繼推出新系列產(chǎn)品,如利勃海爾公司新推出的LR11250型1250t產(chǎn)品,馬尼托瓦克公司的16000型400t、18000型600/750t和21000型907t產(chǎn)品,特雷克斯集團旗下的特雷克斯-德馬格公司新推出的CC8800型1250t、CC2800-1增強型600t、CC2500-1型500t、CC5800型800/1000t產(chǎn)品,神鋼公司新推出的CKE系列(目前最大噸位的是CKE4000型400t)產(chǎn)品。
2.國外大型履帶起重機新技術(shù)
2.1結(jié)構(gòu)方面
(1)臂節(jié)連接。
目前臂節(jié)的連接型式普遍采用4個銷軸同向連接,安裝時4個銷軸同時對位,然后插銷。這種方式安裝較困難。國外產(chǎn)品對此進行了細節(jié)改進,組裝時先對位、安裝臂節(jié)上平面的2個銷軸,然后再對位安裝下平面銷軸,減少安裝難度。圖1a是利勃海爾公司臂節(jié)安裝示意。更為方便的是馬尼托瓦克產(chǎn)品,臂節(jié)上平面力的傳遞方式不再是銷軸型式,而是由定位銷和擠壓面共同完成。定位銷尺寸小,只起到定位作用,力的傳遞完全通過擠壓面實現(xiàn),安裝更簡便。這種新型式已在18000型和21000型產(chǎn)品上成功應(yīng)用。
為降低臂節(jié)連接銷軸直徑,可借鑒履帶板的多個支承面的連接原理,將銷軸剪切面數(shù)由原來的2個增加為3個,這樣銷軸直徑可減小20%,安裝也更為方便。這種新方式多應(yīng)用于大型產(chǎn)品中,如特雷克斯-德馬格的CC2800-1型產(chǎn)品。
(2)變幅系統(tǒng)結(jié)構(gòu)。
20世紀90年代前普遍采用柔性索具作為變幅系統(tǒng)的承載構(gòu)件。索具制作方式是將鋼絲繩兩端采用壓制或澆注方式做成單雙耳接頭,長度與臂節(jié)匹配。由于索具安全系數(shù)高,自重大,剛度小,彈性變形量大,易引起懸垂現(xiàn)象,進一步增大變幅載荷和臂架載荷。為此出現(xiàn)了新的結(jié)構(gòu)型式——高強度拉板,這種高強度拉板承載能力大,屈服極限超過1000MPa,而且一次成型,不需焊接。由于彈性變形小,不存在懸垂現(xiàn)象。采用數(shù)控加工,制作精度高,可省去平衡拉板間載荷的平衡梁。
國外小噸位產(chǎn)品已普遍使用。但考慮銷軸連接處強度問題,拉板兩端寬度較大,可達到中間部位的2倍以上,因此下料時材料利用率低。另外截面是矩形,側(cè)向抗彎抗風振能力差。為節(jié)省材料、增強側(cè)向承載能力,特雷克斯-德馬格公司推出了鋼管型式,該型式可以與臂架管材通用,此外鋼管各向幾何特性相同,抗彎抗扭能力強。但是管與管之間通過臂節(jié)接頭方式連接,需要焊接,焊縫受拉力作用,對焊接要求較高。目前特雷克斯-德馬格公司的CC2800-1產(chǎn)品即應(yīng)用此種型式。
(3)主機結(jié)構(gòu)。
為降低成本,減少結(jié)構(gòu)件質(zhì)量,高強度材料已作為主機結(jié)構(gòu)的首選材料,屈服強度達到500MPa以上。其結(jié)構(gòu)尺寸明顯減小。以LR1750型750t產(chǎn)品為例,轉(zhuǎn)臺、車架、履帶架結(jié)構(gòu)除特殊用板(履帶與車架連接處)外,主要承載板厚度均在35mm以內(nèi)(而以往結(jié)構(gòu)需要40mm以上,常用的是50~70mm的板)。并采用寬肢薄壁結(jié)構(gòu),極大地提高了結(jié)構(gòu)整體穩(wěn)定性和承載能力。主機結(jié)構(gòu)的自重占整機(大基本主臂)自重的比例也由通常的60%降到40%,剩余自重完全由配重和車身壓重分攤??梢娖湓O(shè)計上的精益求精,甚至細致到小小的履帶板也要采用變截面型式。而履帶板的總重通常占履帶架總成的40%,采用變截面型式可使履帶板總重降低10%。
轉(zhuǎn)臺結(jié)構(gòu)型式主要有2大派系,一派是以歐美為代表的封閉式轉(zhuǎn)臺結(jié)構(gòu),另一派是以日本為代表的小箱型轉(zhuǎn)臺結(jié)構(gòu)。封閉式結(jié)構(gòu)由2個高度較大的工字型或箱型截面組成,剛性好,在大型產(chǎn)品中得到廣泛應(yīng)用。小箱型結(jié)構(gòu)在小箱型截面上配置支座連接機構(gòu),兩側(cè)設(shè)置機棚放置發(fā)動機、油箱、回轉(zhuǎn)機構(gòu)等部件。為維修方便,日本新推出半開放式轉(zhuǎn)臺結(jié)構(gòu),一側(cè)放置部件,另一側(cè)設(shè)置走臺板,完全開放,維修者很容易接近機構(gòu)、動力部件,更換易損件或查看運轉(zhuǎn)狀況。
考慮到運輸方便性,對于大噸位起重機需轉(zhuǎn)臺拆解運輸。轉(zhuǎn)臺組合方式有2大類,一是轉(zhuǎn)臺、回轉(zhuǎn)支承與車架一部分連成為一體,轉(zhuǎn)臺其他部分可獨立運輸,或再拆解運輸,如馬尼托瓦克公司的M21000型產(chǎn)品。另一類是將上下車分開運輸,分開部分與回轉(zhuǎn)支承采用快速連接方式,如特雷克斯-德馬格公司的CC5800型產(chǎn)品的快速銷軸連接方式。
下車結(jié)構(gòu)的改進更為明顯??紤]增大行走牽引能力和提高工作速度,行走機構(gòu)可選用四驅(qū)型式。履帶架的結(jié)構(gòu)隨之改進,其張緊通過張緊梁套接于履帶架結(jié)構(gòu)中實現(xiàn),為降低驅(qū)動轉(zhuǎn)矩,驅(qū)動輪采用鏈輪型式,以減小直徑,特雷克斯-德馬格公司的CC2500型產(chǎn)品即采用了這種型式。履帶總成數(shù)量也在發(fā)生根本性改變,不僅僅是傳統(tǒng)的左右2條履帶總成,而是采用多組總成,如馬尼托瓦克公司的21000型產(chǎn)品,下車由8條履帶組成,每兩條履帶為一組,載荷的傳遞原理類似于門座起重機的大車行走結(jié)構(gòu)。每條履帶承載更均勻,對地基的要求也更低,并且可形成寬模式和窄模式,以適應(yīng)不同工作場合的要求,車架結(jié)構(gòu)也有明顯改進,考慮運輸方便性,超大型起重機的車架一般由3部分甚至更多部分組成,中間箱型結(jié)構(gòu)(上端連接回轉(zhuǎn)支承)和兩側(cè)箱型縱梁,更為新穎的結(jié)構(gòu)是改進三者連接方式,使縱梁呈放射性放置,從而減小與履帶架連接處的集中載荷。
2.2臂架組合作業(yè)
臂架組合中,除標準配備:主臂、主臂+固定副臂、主臂+塔式副臂、主臂輕重混合的方式外,為適應(yīng)市場需要,又新增添2種組合方式:重型短副臂和副臂+副臂組合,是重型短副臂組合,但副臂為特制,非常短,專用于化工用各種反應(yīng)塔的吊裝,有較高的提升高度及一定的幅度,關(guān)鍵是超大的起重量,與同長度同幅度下的主臂作業(yè)起重量接近,甚至超過其幅值。
在歐美產(chǎn)品中都已開發(fā)應(yīng)用。圖11b副臂+副臂組合,用于電力建設(shè)方面,以增加作業(yè)空間,如風力發(fā)電設(shè)備的安裝,總臂架組合長度可達到150m以上。這種型式在利勃海爾公司產(chǎn)品得到應(yīng)用。
2.3系列產(chǎn)品的通用性
考慮產(chǎn)品設(shè)計和制造的通用性,歐美三大公司自身的配重從50t到1250t產(chǎn)品均可互換。臂節(jié)的互換性強,甚至對于同一型號不同產(chǎn)品也能做到互換??紤]運輸尺寸限制,臂架的運輸寬度統(tǒng)一,從某種程度上簡化了制造工藝。如特雷克斯-德馬格公司的CC2200、CC2500、CC2800型產(chǎn)品的臂架運輸寬度相同,在3m以內(nèi)。馬尼托瓦克公司產(chǎn)品對同尺寸不同繩徑的卷揚機構(gòu),采用更換繩槽表面也可實現(xiàn)通用化。這些都為安裝運輸使用提供了便利條件。
2.4電氣控制
(1)液壓系統(tǒng)的電子控制。
液壓系統(tǒng)的控制方式由過去開式比例閥控變量系統(tǒng)發(fā)展成為開閉式結(jié)合或全閉式電比例泵控變量系統(tǒng),傳動更平穩(wěn),結(jié)構(gòu)更緊湊。而且液壓系統(tǒng)、發(fā)動機、狀態(tài)與安全保護監(jiān)測、極限載荷控制已全部采用數(shù)據(jù)總線電子控制。各公司也都開發(fā)出各自的電子控制系統(tǒng),如馬尼托瓦克公司的EPIC控制系統(tǒng),利勃海爾公司的LICCON控制系統(tǒng),特雷克斯-德馬格公司的IC-1控制系統(tǒng)。
(2)力矩限制器的無線傳感器方式。
力矩限制器的力傳感器布置方式有多種,通常置于變幅系統(tǒng),即變幅拉板與桅桿(或人字架)連接處,可用拉力傳感器或銷軸傳感器。馬尼托瓦克公司最新采用鋼絲繩用無線拉力傳感器,直接與鋼絲繩楔套相連,由于無線傳感,不受臂長限制,這在其555、16000、18000型新產(chǎn)品上得到應(yīng)用。
(3)大屏幕顯示及多個攝像監(jiān)視器。
從人性化角度采用大屏幕彩屏可顯示更多信息,包括吊裝狀態(tài)參數(shù)、機構(gòu)工作參數(shù)、故障診斷、報警提示,更主要的是可進行吊裝工況選擇與模擬演示,甚至可達到三維模擬演示。另一個安全性考慮是多個攝像頭監(jiān)控,在司機室放置多個監(jiān)視器進行實時顯示。如利勃海爾公司的LR1750型產(chǎn)品,共有5個攝像頭:轉(zhuǎn)臺后方兩側(cè)各1個,便于回轉(zhuǎn)時察看后方情況;轉(zhuǎn)臺上1個,便于察看卷揚排繩;底節(jié)臂和超起桅桿的卷揚處均設(shè)置1個,以察看纏繩情況。使用各種電子眼,大大降低了操作人員的工作強度,提高了工作安全性。
(4)臂架配重的無級變幅。
目前的產(chǎn)品均能保證主臂和副臂作業(yè)時主(副)臂的無級變幅。塔式工況作業(yè)時不僅實現(xiàn)了副臂無級變幅,同時也實現(xiàn)了主臂無級變幅,替代原有的多個主臂固定角度的作業(yè)方式(如85°,75°,65°等)。這種主副臂的同時無級變幅方式增加了作業(yè)覆蓋面及多種作業(yè)工況組合的靈活性,也是電子控制技術(shù)質(zhì)的飛躍。根據(jù)此原理,超起作業(yè)時超起配重的位置也實現(xiàn)了無級調(diào)整,無論是水平還是垂直方向,均可通過油缸或超起桅桿變幅實現(xiàn),極大地減少了各種輔助環(huán)節(jié)。利勃海爾公司率先實現(xiàn)了無級變幅,馬尼托瓦克和特雷克斯-德馬格公司也相繼實現(xiàn)此功能。
由此可見,國外產(chǎn)品不是僅以滿足基本功能要求為目標,而是更注重人性化理念和產(chǎn)品細節(jié),以新理念和細節(jié)設(shè)計贏得市場。每個細節(jié)的改進都需要不斷的創(chuàng)新,以求產(chǎn)品的精益求精。這些新技術(shù)和敬業(yè)精神很值得國內(nèi)同行借鑒。
3.國內(nèi)履帶起重機生產(chǎn)現(xiàn)狀
國內(nèi)履帶起重機的生產(chǎn)歷史較短,目前正處于成長發(fā)展時期,尚無規(guī)模較大的專業(yè)生產(chǎn)企業(yè)。生產(chǎn)履帶起重機的企業(yè)有:撫順挖掘機制造有限責任公司、徐工集團徐州重型機械有限公司、中聯(lián)重科浦沅分公司、上海三一科技有限公司、山東魯能光大重型機械設(shè)備有限公司、哈爾濱四海工程機械制造公司、北方交通公司。國內(nèi)產(chǎn)品從2004年得到迅速發(fā)展,當年銷售量為213臺,比2003年的123臺增長了73.2%。2005年繼續(xù)保持了增長勢頭,截止到10月份累積銷售197臺,同比增長15.5%,但產(chǎn)品以100噸級以下產(chǎn)品為主。隨著市場需求量的不斷增加,企業(yè)在不斷向大規(guī)模、系列化方向發(fā)展。
撫順挖掘機制造有限責任公司是我國唯一批量生產(chǎn)履帶起重機的企業(yè),引進日立技術(shù),產(chǎn)品系列有35t、50t、80t、100t和150t,年產(chǎn)量占國內(nèi)銷售總量的60%左右,高居國內(nèi)榜首。其推出的250t產(chǎn)品融入了新技術(shù),如電比例泵控系統(tǒng),半開放式轉(zhuǎn)臺結(jié)構(gòu)等。預計2006年推出350t產(chǎn)品。
徐工集團徐州重型機械有限公司目前已批量生產(chǎn)50t履帶起重機。1998年與大連理工大學合作開發(fā)了具有自主產(chǎn)權(quán)的150t履帶起重機,隨后研發(fā)了100噸級產(chǎn)品。其自行研制的300t履帶起重機2005年11月已交付用戶,產(chǎn)品風格與日本相同?,F(xiàn)與大連理工大學合作開發(fā)大型系列產(chǎn)品,從200t到1000t,計劃3年內(nèi)完成,現(xiàn)已完成220t、260t產(chǎn)品設(shè)計,正進行450t和650t產(chǎn)品設(shè)計,預計2006年出樣機。
中聯(lián)重科浦沅分公司以生產(chǎn)汽車起重機為主,2002年開始研發(fā)履帶起重機,與大連理工大學合作開發(fā)了70~200t的系列產(chǎn)品,200t產(chǎn)品2005年初下線。70t產(chǎn)品2005年10月下線,100t和160t產(chǎn)品2006年上半年將下線。技術(shù)風格與歐美相同,現(xiàn)與大連理工大學合作開發(fā)300~800t系列產(chǎn)品,計劃3年內(nèi)完成,預計2006年推出600t產(chǎn)品。
上海三一科技有限公司2005年上半年通過400t產(chǎn)品評審,2006年5月召開推介會。已有及后續(xù)研發(fā)產(chǎn)品有50t、80t、150t、200t和250t。
山東魯能光大公司在開發(fā)了50t、80t、100t、200t產(chǎn)品基礎(chǔ)上,也將向大型產(chǎn)品進軍。山東奧奇重工有限公司也正在研發(fā)100~400t級產(chǎn)品。
預計2006年國內(nèi)各制造企業(yè)生產(chǎn)履帶起重機的產(chǎn)值在14億元左右。在技術(shù)水平上國內(nèi)產(chǎn)品與國外還有一定差距,這與國內(nèi)配套力量薄弱不無關(guān)系。目前國內(nèi)產(chǎn)品還處于發(fā)展成長階段,主要目標是首先保證產(chǎn)品的基本功能,在產(chǎn)品細節(jié)及可靠性方面還有待不斷完善,因此造成產(chǎn)品大問題沒有,小問題不斷,在使用上產(chǎn)生諸多不便。改變這種局面的有效措施是注重對產(chǎn)品的敬業(yè)精神和開拓自主創(chuàng)新技術(shù)。從國外產(chǎn)品在細節(jié)上不斷的變化,已明顯看出創(chuàng)新無處不在,只有創(chuàng)新,產(chǎn)品才有持久的生命力。除此以外,大型產(chǎn)品的研發(fā)還要注重基礎(chǔ)性理論研究工作與技術(shù)創(chuàng)新。盡管國內(nèi)企業(yè)通過借鑒吸收國外先進技術(shù)、采取國際化配套,提高產(chǎn)品起點,但是產(chǎn)品質(zhì)量的深入提升需要有:
(1)扎實的理論根基。
(2)研發(fā)資金的投入,技術(shù)隊伍的培養(yǎng)建設(shè)。
(3)新標準新規(guī)范的制訂。
盡快提升產(chǎn)品質(zhì)量、縮短研發(fā)周期的有效途徑是產(chǎn)學研聯(lián)合,發(fā)揮學校、科研院所的基礎(chǔ)理論、技術(shù)研發(fā)實力和企業(yè)制造實力,并求得政府和起重機用戶的支持。學校力量的注入可有效拓展提高企業(yè)技術(shù)隊伍,企業(yè)加大研發(fā)資金的投入,向國家求支持,共同搭建基礎(chǔ)性試驗研究平臺,是技術(shù)創(chuàng)新的可靠保證。規(guī)范的修訂、新標準的編制工作也將會在此基礎(chǔ)上有序的展開。這種方式已在大連理工大學和徐工集團徐州重型機械有限公司、長沙中聯(lián)重科浦沅分公司的合作中得到很好的驗證。
4.結(jié)語
綜上所述可以看出,國內(nèi)大型履帶起重機的研制勢在必行,具備天時(市場需求,政策保護)、地利(地理位置優(yōu)勢、價格優(yōu)勢、國際化配套)、人和(先進設(shè)計理念、技術(shù)手段、企業(yè)技術(shù)隊伍的實力)的條件。但若想贏得更多用戶的支持,獲得市場的認可,還應(yīng)持續(xù)不斷的提升產(chǎn)品性能、質(zhì)量和可靠性,而自主創(chuàng)新技術(shù)的研發(fā)和結(jié)構(gòu)的精細設(shè)計與制造是產(chǎn)品持久生存的根本條件。
Track current situation of the development and the newest technological analysis of hoist market
Track with the weight heavy , homework space heavy taking year walk , earth than press unique advantage such as being light show one's talent from numerous hoists gradually hoist, become the outstanding one in engineering construction. With using the constant increasing of the breadth and depth, the track hoist is changing in such but the respects as the structure , transmitting , controlling,etc., thus consolidated and improved the integral level of the track hoist , made the products perfect constantly.
1.Current situation of hoist market of the domestic track
At present, domestic market is sought-after, the large-scale construction enterprises of every profession and trade import the large-scale track hoist one after another , seize the market commanding point. China Petrochemical Industry Company imported the horse one dose of 1250t track hoists of Germany in 2002, the oil company introduced Liebherr 1250t track hoist again in the first half of 2006. The import of the domestic large-scale track hoist has been already over 100, in 245 and 357 products imported in 2003 and 2004, 800t above large-scale product nearly 5, nearly 10 of 750t, 600t10 Yu Tai, 400- 500t30 Yu Tai. At the end of half by 2006 , has already introduced Model M21000 907t , CC5800 type 800/1000 -ton products at home.
With the constant growth of the market demand of the large-scale track hoist, the performance , quality , dependability to the track hoist require higher and higher. Europe , the United States and Japan put out the new series of products in succession, such as the Model LR11250 1250t products which Liebherr Company introduce newly, the horse Buddhist nun holds type 16000 400t of one gram of companies of tile, type 18000 600/750t and 21000 type 907t products, Trecker Trecker of group then then- doses of Model CC8800 1250t that Company put out newly , horse of Germany ,, enhanced 600t of CC2800-1, products , 500t of Model CC2500-1 and 800/1000t of Model CC5800, supernatural steel CKE series products that Company introduce newly.
2.Hoist new technology of the foreign large-scale track
2.1 structure
( 1) Arm festival connection.
Connection patterns in festival of arm generally adopt 4 pivots to join in the same direction at present, the counterpoint at the same time of 4 pivots while installing, then the socket . It is relatively difficult for this way to install. The foreign products improve the detail to this, 2 pivots in the level in the counterpoint , installation arm festival that while assembling firsting , then install the level pivot in the counterpoint , reduce and install the degree of difficulty . Fig. 1a is installed and hinted by the arm festival of Liebherr Company. Asking tile grams of producting horse Buddhist nun convenient even more, arm section transmission, level of strength way pivot pattern again, but and push the surface to finish together by the locating stud. The locating stud size little, only play the function of orientating, the transmission of strength is totally realized through pushing the surface, install more simple and more convenient. Such new pattern succeed in application at the products in 18000 type and 21000 type already.
In order to reduce the diameter of the connection pivot of festival of arm, a lot of that can draw lessons from the track board supports Taxi connection principle, cutting the tangent plane of the pivot and counting to increase from 2 original to 3, in this way the diameter of the pivot can reduce 20% , it is more convenient too to install. Such new way is applied to the large-scale products more, such as Trecker then- the Model CC2800-1 products of dose of horse of Germany.
( 2) Change a systematic structure.
Generally adopted the flexible rigging as changing a piece of systematic bearing the weight of the component before 1990s. The rigging is made the way adopts both ends of the steel wire rope and suppress or pour the way to make into the single ears and connect, match in length and arm festival. Because the safety coefficient of the rigging is high, it is great to conduct oneself with dignity, rigidity is small, elastic deformation amount is great , apt to cause hanging the phenomenon of hanging down , it is loaded to increase and turn into a load and arm shelf further. The new structure pattern has appeared for this reason - -The high strength draws the board, this kind of high strength draws the bearing capacity of the board big, surrender limit and exceed 1000MPa, and shaping, does not need to weld . Because the elasticity is out of shape and little, do not exist and hang the phenomenon of hanging down . Adopting numerical control to be processed, making is high in precision, can save the balance and draw the loaded balance roof beam among the boards .
The foreign pickup products have already been generally used. But consider the question of intensity of junction of the pivot, it is relatively large in width to draw both ends of the board , can reach more than 2 times of the middle position , so the material utilization ratio is low at the time of unloading. The section is the rectangle in addition, the side direction resists and resists the wind to shake ability badly curved. For save material , strengthen side direction bearing capacity, Trecker then- doses of Company , horse of Germany , introduce the steel tube pattern, pattern this can shelf pipe in common use with arm, in addition to characteristic the same geometry have every steel tube, resist and resist the ability of spraining strongly curved. But join through the piecing way of festival of arm when in charge of and in charge of, need welding , the welding seam receives pulling force function , to welding expecting relatively much. Then Trecker at present - A dose of CC2800-1 products of company of horse of Germany use this kind of pattern promptly.
( 3) Structure of the host computer .
In order to lower costs, reduce structure pieces of quality, high strength material regard as first-selected material, host computer of structure already, surrender the intensity and reach above 500MPa. Its physical dimension is obviously reduced. Taking Model LR1750 750t products as an example, a structure of revolving stage , frame , track is except that use the board (track and frame junction ) specially, bear the weight of the thickness of the board within 35mm mainly (but the past structure needs above 40mm, a commonly used one is the board of 50- 70mm). Adopt the structure of thin wall of wide limb , has improved the whole stability of the structure and bearing capacity greatly. The dead weight of the structure of the host computer accounts for the complete machine (big basic main arm ) the proportion of conducting oneself with dignity drops to 40% from 60% common too, surplus is conducted oneself with dignity to totally press and share again by the counterweight and automobile body. It is obvious what in its designed kept improving , even so careful that the small track board should arrive. And the gross weight of the track board usually accounts for 40% that the track shelf always becomes, it makes the gross weight of the track board reduce by 10% to adopt and turn into the sectional pattern.
The structure pattern of the revolving stage has 2 great factions mainly, one group is the structure of closed revolving stage represented by America and Europe, another group is the small case type revolving stage structure represented by Japan. The closed structure is made up by 2 I-shapes or case type sections bigger in height, rigidity is good, used widely in the large-scale products. The little case type structure disposes the connection organization of a seat, part of putting the engine , fuel tank , transforming to construct in setting up machine canopying on both sides etc. on the little case type section. For maintain convenient, Japan introduce half open revolving stage structure newly, one side put the part, setting up and going a board in another side, totally opening, the persons who maintain are very apt to be close to the organizations , motive force parts, change quick-wear parts or look over the state of operating.
Consider the convenience of transporting, need revolving stage to disassemble transportation to the large tonnage hoist . Revolving stage mode of combination have 2 big class, first , revolving stage , is it support with frame a part becoming an organic whole in succession to turn round, other parts of revolving stage can be transported one gram of Model M21000 products of company independently, or disassemble and transport . Another kind will get on or off the bus and transport separately , will separate it with turning round and supporting and adopting and connecting the way fast partly, if Trecker then- doses of Model CC5800 products of company, horse of Germany, the pivot connect the way fast.
The improvement of the structure is more obvious to get off. Considering increasing and walking and drawing ability and improving the working speed, walking in the organization can select four patterns of driving for use . The improvement thereupon of structure of the track shelf , his one answers and realizes the shelf structure of the track through a urgent roof beam suit urgent, in order to reduce and drive the torque, the drive wheel adopts the pattern of the sprocket , in order to reduce the diameter, Trecker then- doses of Model CC2500 product of Company , horse of Germany , adopt this kind of pattern promptly. The track always becomes the fundamental change is taking place too in the quantity , it is not merely that traditional 2 pieces of track of left and right sides always succeed, adopt many group succeed always , ask tile grams of 21000 type product of Company by Buddhist nun such as horse , it is made up of 8 pieces of track to get off, every two pieces of track are one group, the structure that the cart that the loaded transmission principle is similar to the door seat hoist walks. Each track bears the weight of more even , the requisition for ground is lower too, and can form the wide mode and narrow mode , in order to meet the needs of different working occasions, the structure of the frame has obvious improvement too, considering the transportation convenience, the frame of the ultra large-scale hoist is generally made up by even more parts of 3 parts, the middle case type structure ( joins and turns round and supports on the top ) and case type longeron on both sides, more novel structure is improving by the three and connecting the way, make the longeron present radioactivity to put , thus reduce it with the centralized load of a junction of the track.
2.2 arm shelves make the homework up
In the arm shelf is made up , except that the standard is allocated : Outside the way in which main arm , main arm + regular pair of arms , main arm + tower pair of arms , weight of main arm mix, in order to meet the needs of market , add 2 kinds of modes of combination newly: Heavy-duty short pair of arms and one pair of arms + one pair of arms association, is the heavy-duty short pair of arms association , but one pair of arms is purpose-built , it is very short, use various kinds of reaction towers of hoist and mount special-purposly in the chemical industry, highly there is higher promotioning and certain range , the more important thing is oversize weight of getting up, with get up weight close with between length and main arm homework of range, even exceed its amplitude.
Have already developed and adopted in the American-European products. Fig. 11b one pair of arms + one pair of arms association, used in the electric construction aspect, in order to increase the homework space, such as the installation of the wind-force generating equipment, the total arm shelf can reach above 150m to make the length up . This kind of pattern gets application in Liebherr Company products.
Commonability of 2.3 series of products
The commonability of consider
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