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徐州工程學(xué)院畢業(yè)設(shè)計(jì)(論文)
附錄
附錄1
英文原文
Bridge Crane
Bridge crane is having an elevated track running in a bridge-type crane, also known as the crane. Bridge Crane in the laying of the bridge on both sides along the elevated track on the vertical run, lifting trolley along the bridge laying on the track in the horizontal operation, a scope of work of a rectangle, it can take full advantage of having the space below lifting materials from the ground equipment hindered.
Bridge Crane widely used in indoor warehouses, factories, wharves and open storage yard and other places. Able to carry items, stood up, lifting status, and adjust operations, mainly for the workshop, sections and steel production lines yard, etc.. Lifting capacity usually in the 10 to 100 t. Bridge crane itself for horizontal movement, the winch frame for the vertical movement of the winch suspended from the hook for vertical movement, the direction of movement of three of the crane can work. In order to prevent bridge crane driver not clear in the specific hook campaign, on the ground are equipped with lifting the general command or folder, put hook. If hanging overhead crane hoisted electromagnetic lifting plate, often operated by the drivers themselves. Bridge cranes can be divided into general overhead crane, simple girder bridge crane for bridge crane and metallurgical three.
Ordinary general overhead crane from lifting trolley, having run institutions, having composed of a metal structure. Lifting up from the car and from institutions, agencies and the car running small frame consists of three parts.
Lifting bodies, including the motor, brakes, reducer, and the pulley drum group. Motor through the reducer, driven rotating drum so that the wire rope around 42.50 or 42.50 down to lifting weights. Small frame is from the brackets and install or run agencies and institutions, such as car parts rack, usually welded structure.
Crane running the driving mode can be divided into two categories: one category is the concentrated drive, which uses a motor-driven initiatives on both sides of the drive shaft driven wheel; were driven to another, that is, on both sides of the initiative the wheels with a motor drive. Small, medium and larger overhead crane with brake, and motor reducer combination into one of the "triple play" drive, the weight of the ordinary from the overhead crane for easy installation and adjustment, often drive the use of universal - axis.
Crane normally used only four active and driven wheels, if a great weight, increase common approach to reduce wheel round pressure. When more than four wheels, must adopt a balanced hinged frame device so that the crane load evenly distributed in the wheels.
Bridge metal structure from the main sorghum and sorghum-composed of the main beam is divided into single-and double-girder bridge having two categories. Single-beam bridge from the main beam and a single on both sides of the span at the end of sorghum, dual-beam bridge by the two main sorghum and sorghum-component.
Liang Liang Gang and the end of the link-beam ends with wheels, for supporting an elevated bridge in the running. A main beam welding on track for the lifting trolley running. Having the structure of the main beam type is more a typical box structure, the four truss structure and fasting truss structure.
Box structure can be divided into two-track box girder, partial double-track box-beam, single-bias-rail box and several main sorghum. Dual-track box girder is the extensive use of a basic form, the main beam from the upper and lower flange on both sides of the plate and vertical web composition, layout rail car in the center of the flange plates online, and its simple structure , manufacturing convenient, suitable for mass production, but larger forces.
Partial tracks box-girder and partial double-track box-section of the main beam are from the upper and lower ranges flange plates and thick web of the main components, rail car in the main web layout above, the short Xiangbenna omit the stiffening plate, which tracks box-side main beam from a wide flange box instead of the main sorghum two main sorghum, respect smaller, but more complex manufacturing.
4 truss-type structure from four plane truss structure into a closed space, in the general level of the surface Truss shops follow plate, light weight, rigidity, but compared with other structures, and its dimensions, creating more complex, fatigue lower intensity, has been less productive.
Partial fasting truss structure similar to the main tracks box-girder from the four components of a closed steel structure, in addition to the main web for the Solid shaped beam, the other three plate in accordance with the design requirements cut into many windows, forming a no-ramps Fasting Truss, in the lower level of the surface occupied by taking truss plate, cranes and the operation of electrical equipment installed in the bridge house, lighter forces, the overall stiffness, and that in China is a more widely used type.
General overhead crane used mainly driven power, the general is in the driver indoor manipulation, but also remote control. From the weight of up to 500 tons, up to 60 m span.
Simple beam bridge crane known as sorghum cranes, and the structure and composition of ordinary bridge crane similar to a weight, span and speed are smaller. Bridge is the main sorghum or other steel I-beam and plate steel girder section composed of simple, hand-pull or electric hoist accompanied by gourd simple as lifting trolley car, the car usually in the word sorghum run on the next flange . Bridge can be elevated along the orbit, but also along the elevated suspension in the following orbit, such as a crane hoisted sorghum crane.
Metallurgical dedicated bridge crane in the steel production process can be involved in a specific process operation, and its basic structure and general overhead crane similar, but in small vehicles are equipped with lifting the work of special agencies or devices. This feature is the work of a crane used frequently, poor, working-level higher. Dual-beam bridge crane factories on the track along the vertical direction of movement, the lateral movement and trolley movements campaign to hook work. Applied to machining and assembly shop, a metal structure workshop, mechanical workshops, metallurgy and casting workshop and warehouse type lifting work. With scores from the weight of the form, molecular weight mainly Gouqi, the denominator as vice Gouqi weight. There are five main types.
Casting Crane: for the lifting of hot metal into Mixer, furnaces and molten steel into lifting equipment or continuous ingot steel ingot mould used. Sheng barrels lifting the car, a flip-sheng, deputy trolley barrels, and other auxiliary work.
Tongs crane: Using tongs high temperature steel ingot will be vertically being lifted onto a deep soaking pits, or put it out the car shipped spindles.
Stripper Crane: an ingot from the mandatory extrusion ingot mold. There are special small car Stripper devices, spindles Stripper under way and the shape of the model: Some Stripper crane-is attributable to suppress billets, ingots filed with the clamp module; Some of the clamp punctured ingot mould, with Ingot filed small pair of pliers.
Feeding Crane: Charge will be added to the open hearth furnace. Trolley bottom of the column with the pick-and inciting material to me and it into the furnace. The main column to bypass the vertical axis rotation, pick-and rotary can swing from top to bottom. Deputy car repair furnace for such auxiliary operations.
Forging Crane: to meet with hydraulic forging large workpieces. Trolley displayed on the main hook up special feeder to support and flip the workpiece; Vice car used to lift the workpiece.
Dual-beam bridge crane, the biggest weight from 100 tons, the hook-and-grab, electromagnetic, metallurgical cranes, quenching crane, manual double girder bridge crane, electric hoist double girder overhead crane with the crane unit JB / T14405 "generic bridge crane" standard, the quality of products to JB/T53442 "universal overhead crane product quality grade" first-class requirements. Its structural features of starting up and running with the car running on the bridge, a metal structure for the double-girder box form. From the characteristics of the device in accordance with the classification for the hook, grab, electromagnetic and multipurpose bridge crane, mainly for the mines, factories, wharves and warehouses, and other material handling operations frequent stops, as a crane quenching equipment, a high-speed heat treatment process of decline . Metallurgical casting molten steel crane to transport packet is indispensable than smelting industrial equipment. The use of modern means of science and technology, will enable any crane structure with a jump-speed performance. Can be used with high-level rotating hook for stacking operations.
Single-girder bridge crane, the largest weight of 10 tons from, hook-and-grab, electromagnetic, flying single-girder bridge crane, manual single-girder bridge crane with the crane unit JB/T1306 "electric single-girder bridge Crane "and JB/T2603" electric single-girder overhead crane hoisted the "standard requirements. Its structure is characterized manual or electric hoist monorail car along the main beam under the flange I-beam operation, material handling operations, normally used for workshops, warehouses and other material handling operations, which manual does not allow for single-girder crane No electricity or power occasions. Grab motor with the monorail or bulk materials can also be used to grab operations, the unit crane compact structure, operational flexibility, can be used to ground, can also be used to operate the cab. Special circumstances can also be used for remote operation. Industrial production or storage is indispensable equipment.
Crane normal working hours to allow a lifting of the greatest quality as rated starting weight. Rated crane hook from the hook and the weight does not include the fixed pulley group themselves. Grab sucker and electromagnetic devices, such as the quality of admission included in the ratings from the weight. In accordance with the standard provisions of the bridge crane from the weight of a series of priority number system is R10, from 3.2 t, beginning with the increment of 1.25 Gongpi 4,5,6.3,8,10,12.5,16,20,25,32, 40,50 t……. But domestic products only under the bridge crane years of production practices, from the above series of elected part of the actual composition of a series of weight. Is the most commonly used Series 5 t, 10t, 16t, 20t, 32t and 50 t. Normally, when a weight of more than 10 t, or from the establishment of two bodies, namely the lifting of lifting bodies and institutions, both from the weight of a ratio of about 1:4. Main body from the weight or, for lifting heavy cargo lifting of the weight from the small, but faster, lighter for the lifting of the goods or for supporting efforts to enhance work efficiency.
General may be the biggest crane lifting weights to determine the starting weight, taking into account the conditions of work reproduced or process requirements. Crane does not allow the use of overloading, in the lifting of the frequent changes of the occasion, crane should consider certain margin. In some cases, the occasional object to the lifting of overweight available when two cranes coordinated operations. In the process fixed, the lifting of the weight will remain basically unchanged, the use of cranes loaded with the basic circumstances, can be lifted up from vice, to simplify the structure of a crane and lower costs. Foreign large-tonnage it is not all bridge crane with a lifting body vice, but necessary option.
The use of overhead crane safety matters:
(1) Each crane must be obvious from the weight rated local hang the signs.
(2) Work, it was not allowed on the bridge or hook couriers.
(3) No Operator's Certificate and is not allowed to drink driving cranes.
(4) Operating must focus on the spirit, not talk, smoking or do not do.
(5) To clean the car; while Luanfang equipment, tools, flammable materials, explosive materials and dangerous goods.
(6) The cranes could be allowed to use super.
(7) The following situations while lifting: bundling is not solid; mechanical overload; signal unknown; Cable; buried in the ground or frozen items; suspended on some items; no security protection measures for the flammable and explosive - and dangerous goods; drive liquid items do not meet the safe use of wire rope; fault movements institutions.
(8) The cranes in the absence of obstructions on the lines running, as well as hanging hook or spreader of the base must be more than 2 m from the ground. If the crossing barriers, obstacles to be more than 0.5 m high.
(9) From the weight lifting rated less than 50 per cent of the objects, allowing the two bodies at the same time movements hanging from the weight rating greater than 50% of the objects, only a body can move.
(10) Has the main, the Vice hook overhead crane, not to increase or decrease the same time, Vice hook (exceptional).
(11) While in the objects on a cause or hammering and welding in the work of the following items (can support).
(12) It must be a power outage, and hung in a gated power operation signs, before the examination or maintenance work. If it is necessary to live, work, there must be security protection, and a personal care.
(13) While casually throw things down from the board.
(14) Limit switches and interlock devices, it is necessary to carry out regular checks.
(15) Not used as a parking collision limit switch approach.
(16) Movements brake problems, not lifting weights.
(17)Were not allowed in the hanging objects or equipment over the operation.
(18) Crane unit welding, it is necessary to set up specialized ground, do not use fuselage ground.
(19) Hook in a position under the limit, must remain on the roll more than two laps with the safety of Min Quan.
(20) Crane allowed mutual collisions, but also does not allow use of a crane to promote another crane to work.
(21) Lifting heavy objects, liquid metal and explosive and dangerous goods, must be slowly lifting from the ground 100 to 200 mm, the reliability of brake test.
(22) Repair and inspection of the lights by its voltage must be below 36 V.
(23) Bridge crane cover all electrical equipment should be grounded. If trolley track is not in the main beam welding, the welding earth measures to be taken. Earthing available cross-sectional area greater than 75 mm2 galvanized flat iron or 10 mm2 of bare copper or galvanized more than 30 mm2 bar. Cab of the crane or grounding location should be more than two. Crane power to any point in the neutral grounding resistors, should be less than 4 ?.
(24) Security technology to regular inspection, good pre-preparatory work.
原文翻譯
橋式起重機(jī)
橋式起重機(jī)是橋架在高架軌道上運(yùn)行的一種橋架型起重機(jī)，又稱天車。橋式起重機(jī)的橋架沿鋪設(shè)在兩側(cè)高架上的軌道縱向運(yùn)行，起重小車沿鋪設(shè)在橋架上的軌道橫向運(yùn)行，構(gòu)成一矩形的工作范圍，就可以充分利用橋架下面的空間吊運(yùn)物料，不受地面設(shè)備的阻礙。
橋式起重機(jī)廣泛地應(yīng)用在室內(nèi)外倉庫、廠房、碼頭和露天貯料場等處。能對(duì)物品進(jìn)行搬運(yùn)、翻身、調(diào)整吊運(yùn)狀態(tài)等作業(yè)，主要用于各車間、分段生產(chǎn)線和鋼材堆場等處。起重能力一般在10～100 t。橋式起重機(jī)本身作橫向移動(dòng)，車架上的絞車作縱向移動(dòng)，吊在絞車上的吊鉤作垂向移動(dòng)，三個(gè)方向的運(yùn)動(dòng)的合成才能使起重機(jī)起作用。為了防止橋式起重機(jī)在駕駛員看不清楚具體的吊鉤運(yùn)動(dòng)方式，地面上一般配備有起重工進(jìn)行指揮或夾、放吊鉤。如果橋式起重機(jī)懸掛電磁吊吊運(yùn)鋼板，則往往由駕駛員自己操作。橋式起重機(jī)可分為普通橋式起重機(jī)、簡易粱橋式起重機(jī)和冶金專用橋式起重機(jī)三種。
普通橋式起重機(jī)一般由起重小車、橋架運(yùn)行機(jī)構(gòu)、橋架金屬結(jié)構(gòu)組成。起重小車又由起升機(jī)構(gòu)、小車運(yùn)行機(jī)構(gòu)和小車架三部分組成。
起升機(jī)構(gòu)包括電動(dòng)機(jī)、制動(dòng)器、減速器、卷筒和滑輪組。電動(dòng)機(jī)通過減速器，帶動(dòng)卷筒轉(zhuǎn)動(dòng)，使鋼絲繩繞上卷筒或從卷筒放下，以升降重物。小車架是支托和安裝起升機(jī)構(gòu)和小車運(yùn)行機(jī)構(gòu)等部件的機(jī)架，通常為焊接結(jié)構(gòu)。
起重機(jī)運(yùn)行機(jī)構(gòu)的驅(qū)動(dòng)方式可分為兩大類：一類為集中驅(qū)動(dòng)，即用一臺(tái)電動(dòng)機(jī)帶動(dòng)長傳動(dòng)軸驅(qū)動(dòng)兩邊的主動(dòng)車輪；另一類為分別驅(qū)動(dòng)、即兩邊的主動(dòng)車輪各用一臺(tái)電動(dòng)機(jī)驅(qū)動(dòng)。中、小型橋式起重機(jī)較多采用制動(dòng)器、減速器和電動(dòng)機(jī)組合成一體的“三合一”驅(qū)動(dòng)方式，大起重量的普通橋式起重機(jī)為便于安裝和調(diào)整，驅(qū)動(dòng)裝置常采用萬向聯(lián)軸器。
起重機(jī)運(yùn)行機(jī)構(gòu)一般只用四個(gè)主動(dòng)和從動(dòng)車輪，如果起重量很大，常用增加車輪的辦法來降低輪壓。當(dāng)車輪超過四個(gè)時(shí)，必須采用鉸接均衡車架裝置，使起重機(jī)的載荷均勻地分布在各車輪上。
橋架的金屬結(jié)構(gòu)由主粱和端粱組成，分為單主粱橋架和雙粱橋架兩類。單主粱橋架由單根主粱和位于跨度兩邊的端粱組成，雙粱橋架由兩根主粱和端粱組成。
主粱與端粱剛性連接，端粱兩端裝有車輪，用以支承橋架在高架上運(yùn)行。主粱上焊有軌道，供起重小車運(yùn)行。橋架主粱的結(jié)構(gòu)類型較多比較典型的有箱形結(jié)構(gòu)、四桁架結(jié)構(gòu)和空腹桁架結(jié)構(gòu)。
箱形結(jié)構(gòu)又可分為正軌箱形雙粱、偏軌箱形雙粱、偏軌箱形單主粱等幾種。正軌箱形雙粱是廣泛采用的一種基本形式，主粱由上、下翼緣板和兩側(cè)的垂直腹板組成，小車鋼軌布置在上翼緣板的中心線上，它的結(jié)構(gòu)簡單，制造方便，適于成批生產(chǎn)，但自重較大。
偏軌箱形雙粱和偏軌箱形單主粱的截面都是由上、下翼緣板和不等厚的主副腹板組成，小車鋼軌布置在主腹板上方，箱體內(nèi)的短加勁板可以省去，其中偏軌箱形單主粱是由一根寬翼緣箱形主粱代替兩根主粱，自重較小，但制造較復(fù)雜。
四桁架式結(jié)構(gòu)由四片平面桁架組合成封閉型空間結(jié)構(gòu)，在上水平桁架表面一般鋪有走臺(tái)板，自重輕，剛度大，但與其他結(jié)構(gòu)相比，外形尺寸大，制造較復(fù)雜，疲勞強(qiáng)度較低，已較少生產(chǎn)。
空腹桁架結(jié)構(gòu)類似偏軌箱形主粱，由四片鋼板組成一封閉結(jié)構(gòu)，除主腹板為實(shí)腹工字形粱外，其余三片鋼板上按照設(shè)計(jì)要求切割成許多窗口，形成一個(gè)無斜桿的空腹桁架，在上、下水平桁架表面鋪有走臺(tái)板，起重機(jī)運(yùn)行機(jī)構(gòu)及電氣設(shè)備裝在橋架內(nèi)部，自重較輕，整體剛度大，這在中國是較為廣泛采用的一種型式。
普通橋式起重機(jī)主要采用電力驅(qū)動(dòng)，一般是在司機(jī)室內(nèi)操縱，也有遠(yuǎn)距離控制的。起重量可達(dá)五百噸，跨度可達(dá)60米。
簡易梁橋式起重機(jī)又稱粱式起重機(jī)，其結(jié)構(gòu)組成與普通橋式起重機(jī)類似，起重量、跨度和工作速度均較小。橋架主粱是由工字鋼或其他型鋼和板鋼組成的簡單截面粱，用手拉葫蘆或電動(dòng)葫蘆配上簡易小車作為起重小車，小車一般在工字粱的下翼緣上運(yùn)行。橋架可以沿高架上的軌道運(yùn)行，也可沿懸吊在高架下面的軌道運(yùn)行，這種起重機(jī)稱為懸掛粱式起重機(jī)。
冶金專用橋式起重機(jī)在鋼鐵生產(chǎn)過程中可參與特定的工藝操作，其基本結(jié)構(gòu)與普通橋式起重機(jī)相似，但在起重小車上還裝有特殊的工作機(jī)構(gòu)或裝置。這種起重機(jī)的工作特點(diǎn)是使用頻繁、條件惡劣，工作級(jí)別較高。 雙梁橋式起重機(jī)依靠沿廠房軌道方向的縱向移動(dòng)，小車的橫向移動(dòng)和吊鉤的升降運(yùn)動(dòng)來進(jìn)行工作。適用于機(jī)械加工與裝配車間、金屬結(jié)構(gòu)車間、機(jī)械維修車間、冶金與鑄造車間以及種類倉庫的吊運(yùn)工作等。起重量用分?jǐn)?shù)形式表示，分子為主鉤起重量，分母為副鉤起重量。主要有五種類型。
鑄造起重機(jī)：供吊運(yùn)鐵水注入混鐵爐、煉鋼爐和吊運(yùn)鋼水注入連續(xù)鑄錠設(shè)備或鋼錠模等用。主小車吊運(yùn)盛桶，副小車進(jìn)行翻轉(zhuǎn)盛桶等輔助工作。
夾鉗起重機(jī)：利用夾鉗將高溫鋼錠垂直地吊運(yùn)到深坑均熱爐中，或把它取出放到運(yùn)錠車上。
脫錠起重機(jī)：用以把鋼錠從鋼錠模中強(qiáng)制脫出。小車上有專門的脫錠裝置，脫錠方式根據(jù)錠模的形狀而定：有的脫錠起重機(jī)用項(xiàng)桿壓住鋼錠，用大鉗提起錠模；有的用大鉗壓住錠模，用小鉗提起鋼錠。
加料起重機(jī)：用以將爐料加到平爐中。主小車的立柱下端裝有挑桿，用以挑動(dòng)料箱并將它送入爐內(nèi)。主柱可繞垂直軸回轉(zhuǎn)，挑桿可上下擺動(dòng)和回轉(zhuǎn)。副小車用于修爐等輔助作業(yè)。
鍛造起重機(jī)：用以與水壓機(jī)配合鍛造大型工件。主小車吊鉤上懸掛特殊翻料器，用以支持和翻轉(zhuǎn)工件；副小車用來抬起工件。
雙梁橋式起重機(jī)，最大起重量100噸，吊鉤式，抓斗式，電磁式，冶金起重機(jī)，淬火起重機(jī)，手動(dòng)雙梁橋式起重機(jī)，電動(dòng)葫蘆雙梁橋式起重機(jī) 本單元起重機(jī)符合JB/T14405《通用橋式起重機(jī)》標(biāo)準(zhǔn)的規(guī)定，產(chǎn)品質(zhì)量達(dá)到JB/T53442《通用橋式起重機(jī)產(chǎn)品質(zhì)量分等》一等品要求。 其結(jié)構(gòu)特點(diǎn)式具有起升及運(yùn)行機(jī)構(gòu)的小車位于橋架上運(yùn)行，金屬結(jié)構(gòu)為箱形雙主梁形式。按照取物裝置特點(diǎn)分類為吊鉤，抓斗，電磁以及多用途橋式起重機(jī)，主要用于礦山，工廠，碼頭及倉庫等作業(yè)頻繁的物料搬運(yùn)站，淬火起重機(jī)作為熱處理工藝裝備具有高速下降特性。冶金鑄造起重機(jī)適用于運(yùn)鋼水包，是冶煉工業(yè)比不可少的設(shè)備。采用現(xiàn)代科技手段，可使起重機(jī)的任何一個(gè)結(jié)構(gòu)具備跳速性能。還可配用旋轉(zhuǎn)吊鉤用于高層堆放作業(yè)。
單梁橋式起重機(jī)，最大起重量10噸，吊鉤式，抓斗式，電磁式，懸掛單梁橋式起重機(jī)，手動(dòng)單梁橋式起重機(jī) 本單元起重機(jī)符合JB/T1306《電動(dòng)單梁橋式起重機(jī)》及JB/T2603《電動(dòng)單梁懸掛橋式起重機(jī)》標(biāo)準(zhǔn)規(guī)定。其結(jié)構(gòu)特點(diǎn)是電動(dòng)葫蘆或手動(dòng)單軌小車沿主梁工字鋼下翼緣運(yùn)行，進(jìn)行物料搬運(yùn)作業(yè)，通常用于車間，倉庫等物料搬運(yùn)作業(yè)，其中手動(dòng)單梁起重機(jī)用于不允許用電或者無電源場合。配合馬達(dá)抓斗或單軌抓斗還可用于散裝物料作業(yè)，本單元起重機(jī)結(jié)構(gòu)緊湊，操作靈活，既可用于地面操作，也可用于司機(jī)室操作。特殊要求情況下，還可以進(jìn)行遙控操作。是工業(yè)生產(chǎn)或貯運(yùn)不可缺少的裝備。
起重機(jī)正常工作時(shí)允許一次起吊的最大質(zhì)量稱為額定起重量。吊鉤起重機(jī)的額定起重量不包括吊鉤和動(dòng)滑輪組的自重。抓斗和電磁吸盤等取物裝置的質(zhì)量計(jì)入額定起重量內(nèi)。按標(biāo)準(zhǔn)規(guī)定，橋式起重機(jī)的起重量系列采用的是R10優(yōu)先數(shù)系，從3.2 t開始，按1.25公比遞增為4，5，6.3，8，10，12.5，16，20，25，32，40，50t……。但目前國內(nèi)的橋式起重機(jī)產(chǎn)品只是根據(jù)多年的生產(chǎn)慣例，從上述數(shù)列中選出一部分組成實(shí)際的起重量系列。最為常用的系列是5t，10t，16t，20t，32t和50t。通常，當(dāng)起重量超過10t時(shí)設(shè)兩個(gè)起升機(jī)構(gòu)，即主起升機(jī)構(gòu)和副起升機(jī)構(gòu)，二者起重量之比約為1：4。主起升機(jī)構(gòu)的起重量大，用以起吊重的貨物；副起升機(jī)構(gòu)的起重量小，但速度較快，用以起吊較輕的貨物或作輔助性工作，以提高工作效率。
一般應(yīng)以起重機(jī)可能遇到的最大起吊重物來確定起重量，同時(shí)考慮轉(zhuǎn)載工作的條件或工藝過程的要求。起重機(jī)不允許超載使用，因此在起吊物經(jīng)常發(fā)生變化的場合，起重機(jī)應(yīng)考慮一定的裕量。在某些情況下，偶爾需吊運(yùn)超重物件時(shí)，可用兩臺(tái)起重機(jī)協(xié)同作業(yè)。在工藝流程固定，起吊物重量基本不變，起重機(jī)基本滿載使用的情況下，可以取消副起升機(jī)構(gòu)，以簡化起重機(jī)的結(jié)構(gòu)，降低成本。國外的大噸位橋式起重機(jī)也并不是都帶有副起升機(jī)構(gòu)的，而是按需要選裝。
橋式起重機(jī)的使用安全事項(xiàng):
（1）每臺(tái)起重機(jī)必須在明顯的地方掛上額定起重量的標(biāo)牌。
（2）工作中，橋架上不許有人或用吊鉤運(yùn)送人。
（3）無操作證和酒后都不許駕駛起重機(jī)。
（4）操作中必須精神集中、不許談話、吸煙或做無關(guān)的事情。
（5）車上要清潔干凈；不許亂放設(shè)備、工具、易燃品、易爆品和危險(xiǎn)品。
（6）起重機(jī)不允許超荷使用。
（7）下列情況不許起吊：捆綁不牢；機(jī)件超負(fù)荷；信號(hào)不明；斜拉；埋或凍在地里的物件；被吊物件上有人；沒有安全保護(hù)措施的易燃品、易爆器和危險(xiǎn)品；過滿的液體物品；鋼絲繩不符合安全使用要求；升降機(jī)構(gòu)有故障。
（8）起重機(jī)在沒有障礙物的線路上運(yùn)行時(shí)，吊鉤或吊具以及吊物底面，必須離地面2m以上。如果越過障礙物時(shí)，須超過障礙物0.5m高。
（9）對(duì)吊運(yùn)小于額定起重量50%的物件，允許兩個(gè)機(jī)構(gòu)同時(shí)動(dòng)作；吊大于額定起重量50%的物件，則只可以一個(gè)機(jī)構(gòu)動(dòng)作。
（10）具有主、副鉤的橋式起重機(jī)，不要同時(shí)上升或下降主、副鉤（特殊例外）。
（11）不許在被吊起的物件上施焊或錘擊及在物件下面工作（有支撐時(shí)可以）。
（12）必須在停電后，并在電門上掛有停電作業(yè)的標(biāo)志時(shí)，方可做檢查或進(jìn)行維修工作。如必須帶電作業(yè)時(shí)，須有安全措施保護(hù)，并設(shè)有專人照管。
（13）不許隨便從車上往下亂扔?xùn)|西。
（14）限位開關(guān)和聯(lián)鎖保護(hù)裝置，要經(jīng)常檢查。
（15）不允許用碰限位開關(guān)作為停車的辦法。
（16）升降制動(dòng)器存在問題時(shí)，不允許升降重物。
（17）被吊物件不許在人或設(shè)備上空運(yùn)行。
（18）對(duì)起重機(jī)某部進(jìn)行焊接時(shí)，要專門設(shè)置地線，不準(zhǔn)利用機(jī)身做地線。
（19）吊鉤處于下極限位置時(shí)，卷筒上必須保留有兩圈以上的安全繩圈。
（20）起重機(jī)不允許互相碰撞，更不允許利用一臺(tái)起重機(jī)去推動(dòng)另一臺(tái)起重機(jī)進(jìn)行工作。
（21）吊運(yùn)較重的物件、液態(tài)金屬、易爆及危險(xiǎn)品時(shí)，必須先緩慢地起吊離地面100~200mm，試驗(yàn)制動(dòng)器的可靠性。
（22）修理和檢查用的照明燈，其電壓必須在36V以下。
（23）橋式起重機(jī)所有的電氣設(shè)備外殼均應(yīng)接地。如小車軌道不是焊接在主梁上時(shí)，應(yīng)采取焊接地線措施。接地線可用截面積大于75mm2的鍍鋅扁鐵或10mm2的裸銅線或大于30mm2的鍍鋅圓鋼。司機(jī)室或起重機(jī)體的接地位置應(yīng)多于兩處。起重機(jī)上任何一點(diǎn)到電源中性點(diǎn)間的接地電阻，均應(yīng)小于4Ω。
（24）要定期做安全技術(shù)檢查，做好預(yù)檢預(yù)修工作。
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