房建行業(yè)的塔式起重機動臂裝在高聳塔身上部的旋轉(zhuǎn)起重機。作業(yè)空間大,主要用于房屋建筑施工中物料的垂直和水平輸送及建筑構(gòu)件的安裝。由金屬結(jié)構(gòu)、工作機構(gòu)和電氣系統(tǒng)三部分組成。金屬結(jié)構(gòu)包括塔身、動臂和底座等。工作機構(gòu)有起升、變幅、回轉(zhuǎn)和行走四部分。電氣系統(tǒng)包括電動機、控制器、配電柜、連接線路、信號及照明裝置等。 塔式起重機簡稱塔機,亦稱塔吊,起源于西歐。塔機分為上回轉(zhuǎn)塔機和下回轉(zhuǎn)塔機兩大類。其中前者的承載力要高于后者,在許多的施工現(xiàn)場我們所見到的就是上回轉(zhuǎn)式上頂升加節(jié)接高的塔機。按能否移動又分為:走行式和固定式。固定式塔機塔身固定不轉(zhuǎn),安裝在整塊混凝土基礎(chǔ)上,或裝設(shè)在條形式 X 形混凝土基礎(chǔ)上。在房屋的施工中一般采用的是固定式的。塔式起重機的動臂形式分水平式和壓桿式兩種。動臂為水平式時,載重小車沿水平動臂運行變幅,變幅運動平衡,其動臂較長,但動臂自重較大。動臂為壓桿式時,變幅機構(gòu)曳引動臂仰俯變幅,變幅運動不如水平式平穩(wěn),但其自重較小。 為了確保安全,塔式起重機具有良好的安全裝置,如起重量、幅度、高度和載荷力矩等限制裝置,以及行程限位開關(guān)、塔頂信號燈、測風(fēng)儀、防風(fēng)夾軌器、爬梯護身圈、走道護欄等。司機室要求舒適、操作方便、視野好和有完善的通訊設(shè)備。 以下分幾個方面來具體介紹房建中常用的塔機。 (一)、塔機的金屬結(jié)構(gòu) 塔機的金屬結(jié)構(gòu)由起重臂、塔身、轉(zhuǎn)臺、承座、平衡臂、底架、塔尖等組成。起重臂構(gòu)造型式為小車變幅水平臂架,再往下分又有單吊點、雙吊點和起重臂與平衡臂連成一體的錘頭式小車變幅水平臂架。單吊點是靜定結(jié)構(gòu),雙吊點是超靜定結(jié)構(gòu)。錘頭式小車變幅水平臂架,裝設(shè)于塔身頂部,狀若錘頭,塔身如錘柄,不設(shè)塔尖,故又叫平頭式。平頭式的使結(jié)構(gòu)形式更簡單,更有利于受力,減輕自重,簡化構(gòu)造等優(yōu)點。小車變幅臂架大都采用正三角形的截面。 (二)、塔機的零部件 每臺塔機都要用許多種起重零部件,其中數(shù)量最大,技術(shù)要求嚴而規(guī)格繁雜的是鋼絲繩。塔機用的鋼絲繩按功能不同有:起升鋼絲繩,變幅鋼絲繩,臂架拉繩,平衡臂拉繩,小車牽引繩等。鋼絲繩的特點是:整根的強度高,而且整根斷面一樣大小,強度一致,自重輕,能承受震動荷載,彈性大,能卷繞成盤,能在高速下平衡運動,并且無噪聲,磨損后其外皮會產(chǎn)生許多毛刺,易于發(fā)現(xiàn)并便于及時處置。(三)、塔機的工作機構(gòu) 塔機的工作機構(gòu)有五種:起升機構(gòu)、變幅機構(gòu)、小車牽引機構(gòu)、回轉(zhuǎn)機構(gòu)和大車走行機構(gòu)(行走式的塔機)。 (四)、塔機的電氣設(shè)備 塔機的主要電氣設(shè)備包括:電纜卷筒-中央集電環(huán);電動機;操作電動機用的電器,如:控制器、主令控制器、接觸器和繼電器。保護電器,如:自動熔斷器,過電流繼電器和限位開關(guān)等。主副回路中的控制、切換電器,如:按鈕、開關(guān)和儀表等。屬于輔助電氣設(shè)備的有:照明燈、信號燈、電鈴等。 (五)、塔機的液壓系統(tǒng) 塔機液壓系統(tǒng)中的主要元器件是液壓泵、液壓油缸、控制元件、油管和管接頭、油箱和液壓油濾清器等。液壓泵和液壓馬達是液壓系統(tǒng)中最為復(fù)雜的部分,液壓泵把油吸入并通過管道輸送給液壓缸或液壓馬達,從而使液壓缸或馬達得以進行正常運作。液壓泵可以看成是液壓和心臟,是液壓的能量來源。(六)、塔機的安全裝置 安全裝置是塔機必不可少的關(guān)鍵設(shè)備之一,可以分為:限位開關(guān)(限位器);超負荷保險器(超載斷電裝置);緩沖止擋裝置;鋼絲繩防脫裝置;風(fēng)速計;緊急安全開關(guān);安全保護音響信號。限位開關(guān)按功能有:吊鉤行程限位開關(guān),回轉(zhuǎn)限位開關(guān),小車行程限位開關(guān),大車行程限位開關(guān)。 (七)、塔機的防傾翻規(guī)定 嚴禁超載運行;不得斜牽重物;不許猛然急制動;禁止在大風(fēng)中運行吊運作業(yè);工作班后,必須把夾軌器夾緊,以防大風(fēng)將塔機吹動溜出軌道。 (八)、自升式塔機的附著錨固 當(dāng)自升式塔機在達到其自由高度繼續(xù)向上頂升接高時,為了增強其穩(wěn)定系數(shù)保持起重能力,必須通過錨固附著于建筑結(jié)構(gòu)上。附著層次與施工層建筑總高度、塔機和塔身結(jié)構(gòu)、塔身自由高度有關(guān)。Tower Crane Boommounted on the upper part of the rotation of the tall tower crane. Operating a large space, mainly used for housing construction materials in the vertical and horizontal transportation and installation of building components. From the metal structure, working bodies and the electrical system consists of three parts. Metal structure including the tower moving arms and base and so on. The work of organizations including lifting, luffing, slewing and walking four parts. Electrical systems including motors, controllers, power distribution cabinets, connection lines, signals and lighting devices. Short tower crane tower crane, also known as tower crane, originated in Western Europe. Device characteristics and safety devices Tower crane boom and struts form of sub-horizontal type two kinds. For the horizontal boom, the load car runs along the level luffing boom, luffing movement balance, its long boom, but the greater weight boom. Boom for the strut-type when the tractor boom luffing mechanism Pitch amplitude, amplitude motion than horizontal steady, but its relatively small weight. In order to ensure the safety of tower crane has a good safety device, such as starting weight, range, height and load torque constraints such devices, as well as the travel limit switches, tower lights, wind instrument, wind clip-rail device, Ladders and athletic supporter circle, walkways and railings. Driver's cab demand for comfort, easy operation, good vision and good communications equipment. Used tower crane following specific description in several aspects of the tower crane used room Jianzhong. (1)the tower crane metal structure metal structure is composed of tower crane boom, tower, turret, bearings, balance arm, chassis, composed of apex. Construction boom level luffing jib type of car, and then have a single hanging point down the minutes, double-hanging point and the lifting arm and balance arm fused hammerhead-type level luffing jib car. Single hanging point is statically determinate structure, twin-lift point is statically indeterminate structure. Hammerhead-type trolley level luffing jib installed at the tower top Zhuangruo hammer, shaft, such as hammer handle, no spire, it is also known as flat head style. Flat-style of making structure simpler and more conducive to the force, to reduce weight and simplify construction and so on. Most used car luffing jib equilateral triangle cross-section. (2)the tower crane spare parts Each tower crane must be used in many kinds of lifting parts, of which the largest number of technical requirements are strict and complicated rope specifications. Tower crane wire rope used in accordance with different functions are: lifting wire rope, rope luffing, jib ropes, balance the arm ropes, trolleys and other traction rope. Steel wire rope is characterized by: the entire root, high strength, but also the whole root sections, the size of the same intensity, light weight, able to withstand shock loads, flexible enough to winding into a disk, can be balanced at high speed movement, and no noise, wear and tear After the skin will produce a number of glitches, easy to detect and facilitate the timely disposal. (3)the tower crane working body The tower crane working body there are five: hoisting mechanism, varying from agencies, car towing agencies, institutions and carts Traveling rotary body (walking style tower crane). (4)the tower crane electrical equipment The main tower crane electrical equipment including: Cable Reels - Central collector ring; Motor; Operation of electrical motors, such as: controller, master controller, contactors and relays. Protection of electrical appliances, such as: automatic fuses, over-current relays and limit switches. Vice-loop in the main control switch electrical appliances, such as: buttons, switches and meters. There are auxiliary electrical equipment: lights, lights, bells and so on. (5)tower crane's hydraulic system Tower crane hydraulic system's main components are hydraulic pumps, hydraulic cylinders, control components, tubing and fittings, fuel tank and hydraulic oil filters and so on. Hydraulic pump and hydraulic motor is a hydraulic system of the most complex part of the oil suction pump through the pipeline to the hydraulic cylinders or hydraulic motors, hydraulic cylinder or motor so that normal operation can be carried out. Hydraulic and hydraulic pump can be seen as the heart, is the hydraulic energy source. (6)tower crane safety devices Safety device is essential for the tower crane, one of the key equipment, can be divided into: limit switch (stopper); overload Insurance devices (overload power plant); buffer only block devices; steel wire rope anti-off device; anemometer ; emergency safety switch; security audio signal. Limit switches according to the functions are: hook travel limit switch, rotary limit switches, trolley travel limit switch, carts travel limit switch. (7)the provisions of the tower crane anti-tipping Non-overloading operation; not oblique pull heavy loads; not allowed to suddenly emergency braking; prohibit running wind lifting operations; working class, must be clip-rail clamping device to prevent the wind blowing the tower crane slipped out of orbit. (8)since the l-type tower crane attachment anchor When the self-climbing tower crane in achieving a high degree of their freedom to continue to pick up high-jacking, in order to enhance its stability factor to keep lifting capacity, they must anchor attached to the building structure. Attachment level, the total construction and construction-layer height, tower crane and tower structures, freedom tower height.