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河 北 建 筑 工 程 學(xué) 院
本科畢業(yè)設(shè)計(jì)(論文)
題
目
QTZ125塔式起重機(jī)結(jié)構(gòu)設(shè)計(jì)(63m吊臂)
學(xué) 科 專 業(yè) 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
班 級(jí) 機(jī)094
姓 名 范永田
指 導(dǎo) 教 師 張永清
輔 導(dǎo) 教 師
摘要
QTZ125型塔式起重機(jī)布置合理,外形美觀,使用方便,維修簡(jiǎn)單,工作平穩(wěn),就位快捷方便、高效。該塔機(jī)為上回轉(zhuǎn),水平臂架,小車變幅,液壓自升式多用途塔機(jī),起重力矩為1250KN2m,最大起重量為10T,獨(dú)立架設(shè)最大起升高度可達(dá)200m,最大變幅為63m。
? 變幅機(jī)構(gòu)是為了滿足物料裝卸工作位置要求,充分利用自身的起吊能力(幅度減少能提高起重量),實(shí)現(xiàn)改變幅度的工作機(jī)構(gòu),并用來(lái)擴(kuò)大塔式起重機(jī)的工作范圍,提高生產(chǎn)率。
QTZ125塔式起重機(jī)是通過(guò)移動(dòng)牽引起重小車實(shí)現(xiàn)變幅的。工作時(shí)吊臂安裝在水平位置,小車由變幅牽引機(jī)構(gòu)驅(qū)動(dòng),沿著吊臂軌道(弦桿)移動(dòng)。小車變幅的優(yōu)點(diǎn)是:變幅時(shí)物料做水平移動(dòng),安裝就位方便;速度快、功率省;幅度有效利用率大。其缺點(diǎn)為:吊臂承受較大的彎距,結(jié)構(gòu)笨重,用鋼量大。繩索牽引式變幅機(jī)構(gòu)的小車依靠鋼絲繩牽引沿吊臂軌道運(yùn)行,其驅(qū)動(dòng)力不受附著力的限制,故能在略呈傾斜的軌道上行走,又由于驅(qū)動(dòng)裝置在小車外部,從而使小車自重大為減少,所以適用于大幅度起重量較大的起重機(jī)。在塔式起重機(jī)中大都采用繩索牽引式變幅機(jī)構(gòu),這樣既可以減輕吊臂載荷,又可以使工作可靠,而且因?yàn)轵?qū)動(dòng)裝置放在吊臂根部,平衡重也可以減少。
關(guān)鍵詞:QTZ125塔機(jī)、變幅機(jī)構(gòu)、繩牽引小車式
ABSTRACT
QTZ125 tower crane has reasonable layout, beautiful appearance, it is convenient to use, it is simple to repair, it works stable convenient and efficient. The rotary mode is turning on,ir has horizontal jib, trolley, hydraulic jack-up multi-purpose cranes, its lifting moment is 1250KN 2 m and the maximum lifting weight is 10T the maximum lifting height and amplitude is 200m and 63m.
Luffing mechanism make full use of its lifting capacity of (reduction can improve the weight) to meet the requirement of the material handling work location to change the working mechanism of amplitude and to expand the scope of tower crane work, improve productivity.
QTZ125 tower crane changes amplitude through a mobile traction lifting trolley. When the crane works the jib is installed in a horizontal position, the car alongs the crane rail (chord) move which drived by amplitude traction mechanism.The advantages are: when the trolley works the material move horizontally, it is convenient to install; it has fast speed, it saves power and the effective utilization rate is great. Its shortcomings are: the jib beers a big bending moment, heavy structure and a large quantity of steel. Rope traction luffing car moves along the boom in orbit rely on wire rope traction, its driving force is not affected by adhesion, it can be walking in slightly inclined orbit and because the driver in the car outside, so that the weight of the car is reduced greatly so it is suitable for large amplitude heavy crane. Most of the tower use crane rope traction luffing mechanism which not only can reduce the crane load but also can make reliable work and because the drive device on the jib root the balance weight can also reduced.
Keywords: QTZ125 tower crane, luffing mechanism, rope trolley type
目錄
第一章 前言··················································································1
1.1塔式起重機(jī)概述············································································1
1.2塔式起重機(jī)的發(fā)展趨勢(shì)····································································3
第二章 總體設(shè)計(jì)············································································4
2.1 概述························································································4
2.2 總體設(shè)計(jì)方案的確定······································································5
2.2.1金屬結(jié)構(gòu)·················································································5
2.2.2工作機(jī)構(gòu)················································································25
2.3 總體設(shè)計(jì)原則············································································29
2.3.1 整機(jī)工作級(jí)別··········································································32
2.3.2 機(jī)構(gòu)工作級(jí)別··········································································32
2.3.3 主要技術(shù)性能參數(shù)····································································32
2.4平衡臂與平衡重的計(jì)算···································································33
2.5起重特性曲線·············································································35
2.6塔機(jī)風(fēng)力計(jì)算·············································································37
2.6.1工作工況Ⅰ············································································38
2.6.2工作工況Ⅱ·············································································42
2.6.3工作工況Ⅲ·············································································44
2.6.4非工作工況Ⅳ···········································································46
2.7整機(jī)的抗傾翻穩(wěn)定性·····································································48
2.7.1工作工況Ⅰ·············································································49
2.7.2工作工況Ⅱ·············································································50
2.7.3非工作工況Ⅲ···········································································51
2.7.4工作工況Ⅳ·············································································51
第三章 塔身的設(shè)計(jì)計(jì)算·································································52
3.1塔身的總體模型···········································································52
3.2 塔身的受力分析及驗(yàn)算··································································53
3.2.1.塔身的受力分析·······································································53
3.2.2 塔身內(nèi)力計(jì)算及組合··································································56
3.2.3 塔身整體穩(wěn)定性和強(qiáng)度驗(yàn)算··························································59
第四章 變幅機(jī)構(gòu)的設(shè)計(jì)和計(jì)算························································71
4.1變幅機(jī)構(gòu)的形式··········································································71
4.2 確定卷筒尺寸············································································71
4.2.1 卷筒名義直徑··········································································71
4.2.2 多層繞卷筒相關(guān)參數(shù)計(jì)算····························································72
4.3選擇電動(dòng)機(jī)、減速器、制動(dòng)器、聯(lián)軸器····················································72
4.3.1選擇電動(dòng)機(jī)·············································································72
4.3.2 選擇減速器············································································73
4.3.3 變幅機(jī)構(gòu)制動(dòng)器的選擇·······························································74
4.3.4變幅機(jī)構(gòu)聯(lián)軸器的選擇································································75
4.4. 驗(yàn)算變幅速度···········································································77
4.5驗(yàn)算起、制動(dòng)時(shí)間驗(yàn)算····································································77
4.6電動(dòng)機(jī)發(fā)熱校驗(yàn)···········································································79
4.7 校驗(yàn)卷筒強(qiáng)度············································································80
第五章 變幅小車的設(shè)計(jì)·······························································81
5.1 變幅小車的形式··········································································81
5.2 變幅小車的設(shè)計(jì)··········································································82
5.2.1 繩索牽引式小車構(gòu)造及其驅(qū)動(dòng)方式················································82
5.2.2運(yùn)行小車牽引力計(jì)算···································································83
5.2.3 牽引繩最大張力·······································································86
5.2.4 選擇牽引繩············································································87
5.2.5 牽引卷筒計(jì)算··········································································87
第六章 畢業(yè)設(shè)計(jì)小結(jié)····································································90
致謝····························································································91
參考書(shū)目·······················································································93
河北建筑工程學(xué)院
畢業(yè)設(shè)計(jì)計(jì)算書(shū)
指導(dǎo)教師: 張永清
設(shè)計(jì)題目:設(shè)計(jì)題目:QTZ125塔式起重機(jī)結(jié)構(gòu)設(shè)計(jì)(63m吊臂) 設(shè)計(jì)人:范永田
設(shè)計(jì)項(xiàng)目
計(jì)算與說(shuō)明
結(jié)果
塔式起重機(jī)概述
塔式起重機(jī)的發(fā)展趨勢(shì)
概述
總體設(shè)計(jì)方案的確定
變幅機(jī)構(gòu)
的形式
卷筒尺寸的
確定
選擇電動(dòng)機(jī)
選擇減速器
選擇制動(dòng)器
選擇聯(lián)軸器
驗(yàn)算變幅速
度
起動(dòng)時(shí)間驗(yàn)
算
發(fā)熱校核
校核卷筒強(qiáng)度
變幅小車的設(shè)計(jì)
第一章 前言
1.1 塔式起重機(jī)概述
隨著建筑行業(yè)的興起,城鎮(zhèn)人口的增多,高層建筑已經(jīng)成為了一個(gè)趨勢(shì),來(lái)滿足人們的住房需求。然而,在建筑行業(yè)中,能同時(shí)完成垂直升降和水平移動(dòng)的起重機(jī)械很多,但綜合其機(jī)動(dòng)靈活性,起升高度,實(shí)用性等因素應(yīng)用最廣泛的是塔式起重機(jī)。
塔式起重機(jī)(tower crane)簡(jiǎn)稱塔機(jī),亦稱塔吊,起源于西歐,是現(xiàn)代工業(yè)與民用高層建筑的主要施工機(jī)械之一。在高層建筑中其幅度利用率高達(dá)80﹪,與其它類型的起重機(jī)相比,塔式起重機(jī)的優(yōu)勢(shì)明顯,它有多種類別、形式、性能、大小等,它的突出特點(diǎn)是工作效率高、適用范圍廣、回轉(zhuǎn)半徑大、操作方便可靠等。故塔式起重機(jī)在建筑安裝工程中得到廣泛應(yīng)用。但是塔機(jī)的技術(shù)有待于提高。塔機(jī)的研究正向著組合式發(fā)展。所謂的組合式,就是以塔身結(jié)構(gòu)為核心,按結(jié)構(gòu)和功能特點(diǎn),將塔身分解成若干部分,并依據(jù)系列化和通用化要求,遵循模數(shù)制原理再將各部分劃分成若干模塊。根據(jù)參數(shù)要求,選用適當(dāng)模塊分別組成具有不同技術(shù)性能特征的塔機(jī),以滿足施工的具體需求。推行組合式的塔機(jī)有助于加快塔機(jī)產(chǎn)品開(kāi)發(fā)進(jìn)度,節(jié)省產(chǎn)品開(kāi)發(fā)費(fèi)用,并能更好的為客戶服務(wù)。
據(jù)相關(guān)文獻(xiàn)記載,有關(guān)塔機(jī)的第一項(xiàng)專利早在1900年獲得批準(zhǔn),近代塔式起重機(jī)出現(xiàn)于1912-1914年。第一臺(tái)比較完整的近代塔式起重機(jī)出現(xiàn)于1923年。1930年德國(guó)已經(jīng)開(kāi)始將塔式起重機(jī)批量生產(chǎn)并投入使用,并用于建筑施工。1941年,有關(guān)塔機(jī)的德國(guó)工業(yè)標(biāo)準(zhǔn)DIN8770公布。該標(biāo)準(zhǔn)規(guī)定以吊載(t)和幅度(m)的乘積(tm)一起以重力矩表示塔機(jī)的起重能力。
我國(guó)對(duì)塔機(jī)的研究生產(chǎn)已有近50年的歷史,經(jīng)歷了一個(gè)從繪制仿制到自行設(shè)計(jì)的發(fā)展過(guò)程。在不斷的摸索中,我國(guó)逐步掌握了塔機(jī)生產(chǎn)的生產(chǎn)技術(shù)。20世紀(jì)80年代改革開(kāi)放以后,我國(guó)引進(jìn)了許多先進(jìn)技術(shù),這極大的促進(jìn)了我國(guó)塔機(jī)設(shè)計(jì)制造技術(shù)的進(jìn)步,一些主要機(jī)種已達(dá)到或接近國(guó)外同類產(chǎn)品質(zhì)量水平。我國(guó)的塔式起重機(jī)從科研到加工生產(chǎn)方面取得了可喜的進(jìn)步,但是在和國(guó)外先進(jìn)塔式起重機(jī)的使用壽命,成本等方面還存在著一定的差距。我相信在今后的發(fā)展中差距會(huì)進(jìn)一步縮小。
隨著高層建筑結(jié)構(gòu)件的預(yù)制裝配化、工廠化等新工藝、新技術(shù)應(yīng)用的不斷擴(kuò)大。拿來(lái)與創(chuàng)新,我們要學(xué)習(xí)國(guó)外先進(jìn)技術(shù),并能夠創(chuàng)造出自己的品牌。在新產(chǎn)品開(kāi)發(fā)上我們要學(xué)習(xí)國(guó)外塔機(jī)的一些特點(diǎn):
⑴ 更多的廠家注重開(kāi)發(fā)經(jīng)濟(jì)型城市塔機(jī)并擴(kuò)展成系列。
⑵國(guó)外塔機(jī)新產(chǎn)品中,有一些新穎的輕、中型折疊式快速安裝塔機(jī)頗引人注目。
⑶根據(jù)一些國(guó)家城建當(dāng)局的有關(guān)規(guī)定,為防止塔機(jī)臂架在狹窄的空間運(yùn)行發(fā)生矛盾,避免吊臂相互碰撞以及碰到鄰近的建筑物,在城市高層建筑密集地區(qū)施工必須采用動(dòng)臂式自升塔式起重機(jī)。
⑷在經(jīng)過(guò)較長(zhǎng)時(shí)間研制之后,履帶式水平臂架塔機(jī)作為一種新產(chǎn)品正式問(wèn)世。
⑸變頻調(diào)速系統(tǒng)在國(guó)外塔機(jī)新產(chǎn)品上得到推廣應(yīng)用。
⑹高新技術(shù)開(kāi)始在塔機(jī)上應(yīng)用。
⑺無(wú)論上回轉(zhuǎn)或下回轉(zhuǎn)式塔機(jī),都十分重視駕駛室的平面設(shè)計(jì)和空間處理。
本次設(shè)計(jì)的課題為QTZ125自升勢(shì)塔式起重機(jī)的設(shè)計(jì),根據(jù)其分類特點(diǎn)采用上回轉(zhuǎn)式。
QTZ125型自升式塔式起重機(jī),其吊臂長(zhǎng)63米,最大起重量10噸,額定起重力矩125噸米。是一種結(jié)構(gòu)合理、性能比較優(yōu)異的產(chǎn)品,比較目前國(guó)內(nèi)外同規(guī)格同類型的塔機(jī)具有更多的優(yōu)點(diǎn),能滿足高層建筑施工的需要,可用于建筑材料和構(gòu)件的調(diào)運(yùn)和安裝,并能在市內(nèi)狹窄地區(qū)和丘陵地帶建筑施工。整機(jī)結(jié)構(gòu)大,可滿足中大型施工隊(duì)的要求。
本機(jī)以基本高度(獨(dú)立式)47.3米。用戶需高層附著施工,只需提出另行訂貨要求,即可增加某些部件實(shí)現(xiàn)本機(jī)的最大設(shè)計(jì)高度200米,也就是附著高層施工可建高樓65層以上。
1.2塔式起重機(jī)的發(fā)展趨勢(shì)
根據(jù)國(guó)內(nèi)外一些技術(shù)資料的介紹,塔式起重機(jī)的發(fā)展趨勢(shì)具體歸納為以下幾個(gè)方面。
1、吊臂長(zhǎng)度加長(zhǎng)
在20世紀(jì)60年代初,吊臂長(zhǎng)度超過(guò)40m的較少,70年代吊臂長(zhǎng)度已能做到70m??焖俨鹧b下回轉(zhuǎn)塔式起重機(jī)的吊臂長(zhǎng)度可達(dá)到35m。自升式塔式起重機(jī)吊臂是可以接長(zhǎng)的,標(biāo)準(zhǔn)臂長(zhǎng)一般為30~40m,可以接長(zhǎng)到50~60m。重型塔式起重機(jī)吊臂則更長(zhǎng)。隨著塔式起重機(jī)設(shè)計(jì)水平的提高,可以解決由臂長(zhǎng)加大帶來(lái)的一些技術(shù)問(wèn)題,而低合金高強(qiáng)度鋼材及鋁合金的廣泛采用也為加長(zhǎng)吊臂提供了非常有利的條件。
2、工作速度提高,且能調(diào)速
由于調(diào)速技術(shù)的進(jìn)步,混輪組倍率的可變、雙速、三速電動(dòng)機(jī)及直流電動(dòng)機(jī)調(diào)速的應(yīng)用,使塔式起重機(jī)工作速度逐漸提高。20世紀(jì)50年代生產(chǎn)的塔式起重機(jī)工作速度較低,起升速度一般只有20~30m/min,回轉(zhuǎn)速度為0.6~1r/min,變幅速度為30~40m/min,大車行走速度為10~40m/min,而近幾年來(lái)塔式起重機(jī)工作速度已有提高。起升機(jī)構(gòu)普遍做到具有3~4種工作速度,重物起升速度超過(guò)100m/min者已經(jīng)很多,構(gòu)件安裝就位速度可在0~10m/min范圍內(nèi)進(jìn)行選擇,回轉(zhuǎn)速度一般可在0~1r/min之間進(jìn)行調(diào)節(jié),小車牽引和塔式起重機(jī)行走大多也有2~3種工作速度,小車牽引速度最快可達(dá)60m/min。
3、改善操縱條件
隨著塔式起重機(jī)向大型、大高度方向發(fā)展,操作人員的能見(jiàn)度越來(lái)越差。因此需要在吊臂端部或小車上安裝電視攝像機(jī),在操作室利用電視進(jìn)行操作。有的還采用了雙頻道的無(wú)線電遙控系統(tǒng),不僅可由地面的操作人員控制吊裝,還可以根據(jù)事先編排的程序自動(dòng)進(jìn)行吊裝。
4、更多地采用組裝式結(jié)構(gòu)
為了便于產(chǎn)品更新?lián)Q代,簡(jiǎn)化設(shè)計(jì)制造、使用與管理,提高塔式起重機(jī)使用的經(jīng)濟(jì)效益,國(guó)外塔式起重機(jī)專業(yè)廠已做到產(chǎn)品系列化、部件模數(shù)化。以不同模數(shù)塔身、臂架標(biāo)準(zhǔn)節(jié)組合成變斷面塔身和臂架,這不僅能提高塔身、臂架的力學(xué)性能,減輕塔式起重機(jī)自重,而且可明顯減少使用單位塔架、臂架的儲(chǔ)備量,為降低成本、簡(jiǎn)化管理創(chuàng)造了條件。
第二章 總體設(shè)計(jì)
2.1概述
塔式起重機(jī)是工業(yè)與民用建筑施工中,完成預(yù)制構(gòu)件及其他建筑材料與工具等吊裝工作的主要設(shè)備。在高層建筑施工中其幅度利用率比其他類型起重機(jī)高。塔式起重機(jī)的起升高度、工作幅度和起重力矩都很大,這就要對(duì)其受力、穩(wěn)定性等進(jìn)行考慮與計(jì)算。塔機(jī)的主要性能參數(shù)包括:起重量、起升高度、幅度、各機(jī)構(gòu)工作速度、重量指標(biāo)和起重力矩等。這些參數(shù)表明了起重機(jī)的工作性能和技術(shù)經(jīng)濟(jì)指標(biāo),它是設(shè)計(jì)塔式起重機(jī)的技術(shù)依據(jù),也是生產(chǎn)中選擇塔式起重機(jī)技術(shù)性能的依據(jù)。
總體設(shè)計(jì)是機(jī)械設(shè)計(jì)整個(gè)過(guò)程中最關(guān)鍵的環(huán)節(jié)之一。它是使設(shè)計(jì)產(chǎn)品滿足技術(shù)參數(shù)及形式的總構(gòu)想,決定了機(jī)械設(shè)計(jì)的成敗。在總體設(shè)計(jì)前,應(yīng)先進(jìn)行深入細(xì)致的調(diào)查研究,收集國(guó)內(nèi)外同類機(jī)型的相關(guān)資料,了解國(guó)內(nèi)外塔機(jī)的使用情況,并進(jìn)行分析比較,然后制定總的設(shè)計(jì)方案。設(shè)計(jì)原則應(yīng)當(dāng)在保證所設(shè)計(jì)的機(jī)型達(dá)到國(guó)家有關(guān)標(biāo)準(zhǔn)的同時(shí),力求結(jié)構(gòu)合理,技術(shù)先進(jìn),積極性好,工藝簡(jiǎn)單,工作可靠。
2.2總體設(shè)計(jì)方案的確定
QTZ125型塔式起重機(jī)是上回轉(zhuǎn)、水平臂架、液壓自升式的結(jié)構(gòu)形式,由金屬結(jié)構(gòu)、工作機(jī)構(gòu)和驅(qū)動(dòng)控制系統(tǒng)三部分組成。在進(jìn)行總體設(shè)計(jì)時(shí),要綜合考慮塔機(jī)的強(qiáng)度、剛度、穩(wěn)定性、各種工況下的外載荷以及塔機(jī)的經(jīng)濟(jì)性,從而選出合理的設(shè)計(jì)方案。
2.2.1 金屬結(jié)構(gòu)
塔式起重機(jī)金屬結(jié)構(gòu)部分由塔身,塔頭或塔帽,起重臂架,平衡臂架,回轉(zhuǎn)支撐架等主要部件組成。對(duì)于特殊的塔式起重機(jī),由于構(gòu)造上的差異,個(gè)別部件也會(huì)有所增減。
金屬結(jié)構(gòu)是塔式起重機(jī)的骨架,承受塔機(jī)的自重載荷及工作時(shí)的各種外載荷,是塔式起重機(jī)的重要組成部分,其重量通常約占整機(jī)重量的一半以上,因此金屬結(jié)構(gòu)設(shè)計(jì)合理與否對(duì)減輕起重機(jī)自重,提高起重性能,節(jié)約鋼材以及提高起重機(jī)的可靠性等都有重要意義。
1.基礎(chǔ)
高層建筑施工用的附著式塔式起重機(jī)都采用小車變幅的水平臂架,幅度大部分在五十米以上,無(wú)須移動(dòng)作業(yè)即可覆蓋整個(gè)施工范圍,因此多采用鋼筋混凝土基礎(chǔ)。
鋼筋混凝土基礎(chǔ)有多種形式可供選用。對(duì)于有底架的固定自升式塔式起重機(jī),可視工程地質(zhì)條件,周圍環(huán)境以及施工現(xiàn)場(chǎng)情況選用X形整體基礎(chǔ),四個(gè)條塊分隔式基礎(chǔ)或者四個(gè)獨(dú)立塊體式基礎(chǔ)。對(duì)于無(wú)底架的自升式塔式起重機(jī)則采用整體式方塊基礎(chǔ)。
X形整體基礎(chǔ)的形狀及平面尺寸大致與塔式起重機(jī)X形底架相似。塔式起重機(jī)的X形底架通過(guò)預(yù)埋地腳螺栓固定在混凝土基礎(chǔ)上,此種形式多用于輕型自升式塔式起重機(jī),如圖2-1所示。
長(zhǎng)條形基礎(chǔ)由兩條或四條并列平行的鋼筋混凝土底梁組成,其功能猶如兩條鋼筋混凝土的鋼軌軌道基礎(chǔ),分別支承底架的四個(gè)支座和由底架支座傳來(lái)的上部荷載。如果塔機(jī)安裝在混凝土砌塊人行道上,或是安裝在原有混凝土地面上,均可采用這種鋼筋混凝土基礎(chǔ),如圖2-2所示。
固定式塔式起重機(jī),可靠的地基基礎(chǔ)是保證塔機(jī)安全使用的必備條件。該基礎(chǔ)應(yīng)根據(jù)不同地質(zhì)情況,嚴(yán)格按照規(guī)定制作。除在堅(jiān)硬巖石地段可采用錨樁地基(分塊基礎(chǔ))外,一般情況下均采用整體鋼筋混凝土基礎(chǔ)。對(duì)基礎(chǔ)的基本要求有:基礎(chǔ)的土質(zhì)應(yīng)堅(jiān)固牢實(shí),要求承載能力大于0.15Mpa;混凝土基礎(chǔ)的深度﹥1100毫米,總混凝土方量約16.3立方米,基礎(chǔ)重量約39噸;混凝土基礎(chǔ)的承受壓力不小于8MPa;混凝土基礎(chǔ)應(yīng)根據(jù)現(xiàn)場(chǎng)地質(zhì)情況加工作層或多層鋼筋網(wǎng),鋼筋間距約為250毫米;混凝土基礎(chǔ)表面應(yīng)校水平,不平度小于1/500;混凝土基礎(chǔ)表面設(shè)置排水溝。將底架拼裝組合,對(duì)準(zhǔn)20顆預(yù)埋地腳螺栓,將其放置在混凝土基礎(chǔ)上,注意墊平墊實(shí),并校平底架上平面,要求不平度小于或等于1/1000,擰緊20顆地腳螺栓。調(diào)水平度時(shí)用楔形調(diào)整塊及薄鐵板等。
2.底架結(jié)構(gòu)
底架由工字鋼焊接成整體框架結(jié)構(gòu)。在四角輻射狀安裝有四條可拆支腿,該支腿由工字鋼焊接成,運(yùn)輸時(shí)拆除支腿,以減小運(yùn)輸尺寸。底架上有20個(gè)預(yù)埋地腳螺栓,規(guī)格M48。底架外輪廓尺寸約為6000X6000,高350。
3.塔身結(jié)構(gòu)
塔身結(jié)構(gòu)也稱塔架,是塔機(jī)結(jié)構(gòu)的主體,有轉(zhuǎn)與不轉(zhuǎn)之別;并有內(nèi)塔與外塔之分。塔身結(jié)構(gòu)斷面分為圓形斷面、三角形斷面及方形斷面三類。現(xiàn)今國(guó)內(nèi)外生產(chǎn)的塔機(jī)均采用方形斷面塔身結(jié)構(gòu)。按塔身結(jié)構(gòu)主弦桿材料的不同,這類方形斷面塔架可分為:角鋼焊接格桁結(jié)構(gòu)塔身,主弦桿為角鋼輔以加強(qiáng)筋的矩形斷面格桁結(jié)構(gòu);角鋼拼焊方鋼管格桁結(jié)構(gòu)塔身及無(wú)縫鋼管焊接格桁結(jié)構(gòu)塔身。
常用的斷面尺寸有:1.3m×1.3m,1.4m×1.4m,1.5m×1.5m,1.6m×1.6m,1.7m×1.7m,1.8m×1.8m,2.0m×2.0m。根據(jù)承載能力的不同,同一種截面尺寸,其主弦桿又有兩種不同截面之分。主弦桿截面較大的標(biāo)準(zhǔn)節(jié)用于下部塔身,主弦桿截面較小的標(biāo)準(zhǔn)節(jié)則用于上部塔身。
⑴塔身標(biāo)準(zhǔn)節(jié)
塔身標(biāo)準(zhǔn)節(jié)的長(zhǎng)度有2.5m,3m,3.33m,4.5m,5m,6m,
10m等多種規(guī)格,常用的尺寸是2.5m和3m。本次設(shè)計(jì)采用格桁架結(jié)構(gòu)塔身,其中塔身截面尺寸采用1.8m×1.8m,標(biāo)準(zhǔn)節(jié)的長(zhǎng)度為2.5m。如圖2-6所示:
塔身標(biāo)準(zhǔn)節(jié)用無(wú)縫鋼管焊接而成,節(jié)高2500mm。在標(biāo)準(zhǔn)節(jié)下部管口處車有定位止口,而另一端則焊有定位凸臺(tái),靠相應(yīng)的接合面定位。上下端各用8個(gè)M54的40Cr螺栓聯(lián)結(jié)。各標(biāo)準(zhǔn)節(jié)均設(shè)有供人上下的爬梯,每三個(gè)標(biāo)準(zhǔn)節(jié)設(shè)置一個(gè)休息臺(tái)。
塔身標(biāo)準(zhǔn)節(jié)的聯(lián)接方式有:蓋板螺栓聯(lián)接,套柱螺栓聯(lián)接,承插銷軸聯(lián)接和瓦套法蘭聯(lián)接。本次設(shè)計(jì)的QTZ125塔機(jī)采用套柱螺栓聯(lián)接,其特點(diǎn)是:套柱采用企口定位,螺栓受拉,用低合金結(jié)構(gòu)鋼制作。適用于方鋼管和角鋼主弦桿塔身標(biāo)準(zhǔn)節(jié)的聯(lián)接,加工工藝要求比較復(fù)雜,但安裝速度比較快。
⑵塔身結(jié)構(gòu)設(shè)計(jì)要領(lǐng)
1)多層建筑施工用快速安裝塔機(jī)可根據(jù)起升高度和運(yùn)輸條件分別采用整體式塔身、伸縮式塔身或折疊式塔身。
輕、中型自升塔機(jī)和內(nèi)爬式塔機(jī)宜采用整體式塔身標(biāo)準(zhǔn)節(jié)。附著式自升式塔機(jī)和起升高度大的軌道式以及獨(dú)立式自升塔機(jī)宜采用拼裝式塔身標(biāo)準(zhǔn)節(jié)。
拼裝式塔機(jī)塔身標(biāo)準(zhǔn)節(jié)的加工精度要求比較高,制作難度較大,零件多和拼裝麻煩。但拼裝式塔身標(biāo)準(zhǔn)節(jié)的優(yōu)越性更不容忽視:一是堆放儲(chǔ)存占地小,二是裝卸容易,三是運(yùn)輸費(fèi)用便宜,特別是長(zhǎng)途陸運(yùn)和運(yùn)洋海運(yùn),由于利用集裝箱裝運(yùn),其抗銹蝕和節(jié)約運(yùn)費(fèi)的效果極為顯著。
QTZ125型塔式起重機(jī)為大型自升塔機(jī),綜合以上特點(diǎn),其塔身結(jié)構(gòu)選用整體式塔身標(biāo)準(zhǔn)節(jié)。
2) 為減輕塔身的自重,充分發(fā)揮鋼材的承載能力,并適應(yīng)發(fā)展組合制式塔機(jī)的需要,對(duì)于達(dá)到40m起升高度的塔機(jī)塔身宜采用兩種不同規(guī)格的塔身標(biāo)準(zhǔn)節(jié),而起升高度達(dá)到60m的塔機(jī)塔身宜采用3種不同規(guī)格的塔身標(biāo)準(zhǔn)節(jié)。除伸縮式塔身結(jié)構(gòu)和中央頂升式自升塔機(jī)的內(nèi)塔外,塔身結(jié)構(gòu)上、下的外形尺寸均保持不變,但下部塔身結(jié)構(gòu)的主弦桿截面則須予以加大。
3)塔身的主弦桿可以是角鋼、角鋼拼焊方鋼管、無(wú)縫鋼管式實(shí)心圓鋼,取決于塔身的起重能力、供貨條件、經(jīng)濟(jì)效益以及開(kāi)發(fā)系列產(chǎn)品的規(guī)劃和需要。
4)塔身節(jié)內(nèi)必須設(shè)置爬梯,以便司機(jī)及機(jī)工可以上下。在設(shè)計(jì)塔身標(biāo)準(zhǔn)節(jié),特別是在設(shè)計(jì)拼裝式塔身標(biāo)準(zhǔn)節(jié)時(shí),要處理好爬梯與塔身的關(guān)系,以保證使用安全及安裝便利。
爬梯寬度不宜小于500mm,梯級(jí)間距應(yīng)上下相等,并應(yīng)不大于300mm。當(dāng)爬梯高度大于5m時(shí),應(yīng)從高2m處開(kāi)始裝設(shè)直徑為650~800mm的安全護(hù)圈,相鄰兩護(hù)圈間距為500mm。安全護(hù)圈之間用3根均布的豎向系條相聯(lián)。安全護(hù)圈應(yīng)能承受來(lái)自任何方向的10kN的沖擊力而不折斷。當(dāng)爬梯高度超過(guò)10m時(shí),爬梯應(yīng)分段轉(zhuǎn)接,在轉(zhuǎn)接處加一休息平臺(tái)。
休息平臺(tái)應(yīng)能承受相當(dāng)于3000N的移動(dòng)集中載荷。休息平臺(tái)鋪板可用防滑花紋鋼板或穿孔板、拉網(wǎng)板制成。休息平