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1、<p>  本科畢業(yè)設(shè)計(論文)</p><p><b>  外文資料及翻譯</b></p><p>  年 級: 2007級</p><p>  學(xué) 號: 20077657</p><p><b>  姓 名: </b></p><p>  專

2、 業(yè): 工程機械</p><p><b>  指導(dǎo)老師: </b></p><p><b>  2011年 5 月</b></p><p>  Loading machines </p><p>  For materials handing in construction,use is m

3、ade of loaders.Practice has shown that excavators are less effective in the capacity of loads in quarries and storages of nonmetallic materials than loaders.</p><p>  By the kind of loads handled,loaders are

4、 classified as forklift loads and scooping loaders for loose materials.Sooping loaders are divided into single-bucket and continuous-action Multi-bucket loaders.Single-bucket loaders are general-purpose machines suited e

5、ngineering and in applications requring continuous working process. </p><p>  Depending on the kind of running gear,crawler and anailable.Crawler loaders have a high passblibity and develop a great thrust ef

6、ftort. Wheeled loaders feature a high manoeuvrability and high traveling speeds making no damage to the road pavement and the storage areas.</p><p>  Unloaders are used for unloading sand, gravel, crushed st

7、one, cement form railway cars.</p><p>  Power and pneumatic unloaders are used,power for unloading materials from flat cars or gondola cars(open wagons)and pneumatic for unloading cement.</p><p>

8、;  The main working member of fork-lift loaders is the fork serving to load and unload piece loads. These loaders have different change attachments. When equipped with buckets or grabs, they are used for loading loose an

9、d small-piece materials, and the boom attachment makes these loaders suited for hoisting loads to a small heighe and sometimes for erection work in construction.</p><p>  Fork-lift loaders are operated on ha

10、rd-pavement areas,therefore they are mainly used in storehouse and as factory materials-handing equipment.They are made on the basis of a truck therefore they are also called truck loaders.they are powered by internal co

11、mbustion engines or electric motors with storage batteries. </p><p>  Engine powered truck are used for large warehouse and stock-handing application, for general yard work and fpr loading and unloading of v

12、ehicles. Torque converter transmission provides smooth operation; power steering and all-weather cabs are options available.</p><p>  Single-bucket loaders have a crawler tractor or a wheeled truck as a carr

13、ier mounting. The loader permits mechanization of loading construction and erection and work with the aid of change attachments,of which the main one is the bucket. The loading equipment is available in three modificatio

14、ns: front-end,overloading, and half-swing,jib-type. The front-end attachment provides also side unloading.The overloading modifiactaion permits back unloading.</p><p>  Presently front-end loader with the po

15、sitive displacement hydraulic drives for the attachment are most widely used.</p><p>  The output of multi-bucket loaders is 40 to 60 percent higher than of single-bucket machines at the same power rating,it

16、 is expedient to use them in brickyards,prefabricated concrete products plants,railway stations with large volumes of loading-unloading operatins and also for loading loose materials.In addition,they are suited for size

17、grading of loose materials,for which purpose they are provided with special vibrating screens.</p><p>  Multi-bucket loaders are very efficient in unloading flatcars with side dumping of the handle material.

18、These loaders can be applied in the production lines of prefabricatde ainstruction products plants and also in road building.In the latter case they are used for loading sand and gravel into drying drums and mixers.</

19、p><p>  The working member of the loader is a screw feeder consisting of tow right-hand and left-hand screws,which are arranged on both sides of a bucket elecator.When the feeder rotates,the loaded material is

20、delivered to the buckets to make the scooping easier.A scraper is secured underneath the screw feeder.The elevator of the multi-bucket loader usually dischanges the material onto belt conveyers that deliver it to tianspo

21、rt facilities.</p><p>  Some loaders discharge the handle material into tranport facilities through hoppers or chutes.</p><p><b>  裝載機</b></p><p>  在建筑施工中,材料的裝卸是用裝載機和寫在機

22、進行的。實踐證明,在采石場和非金屬材料的倉庫作業(yè)中,挖掘機的裝在效率要比裝載機高。</p><p>  根據(jù)所裝載材料的種類,裝載機可以分為叉式裝載機,用于裝在整塊物料;鏟斗式裝載機,用于裝載松散物料。鏟斗裝載機分為單斗裝載機和連續(xù)作業(yè)多斗裝載機。單斗裝載機式通用機械,適用于多種條件下作業(yè)。多斗裝載機用于大型倉庫、公路工程以及需要連續(xù)作業(yè)的工作。</p><p>  按照行走裝置的類型,可

23、以分為履帶行走裝載機和輪胎式裝載機。履帶行走式裝載機具有良好的通過性,能產(chǎn)生很大的推進力。輪胎裝載機機動性能良好。行走速度快,對公路路面和存活地面從不產(chǎn)生破壞作用。</p><p>  裝載機用來卸掉火車車廂里的砂子、礫石、碎石和水泥。</p><p>  卸載機分為機動卸載和氣動卸載機。既定卸載機用于從平板貨車或敞蓬車上卸貨;氣動卸載機用于卸水泥。</p><p>

24、;  叉車的主要工作裝置是用于裝卸整件貨物的叉子。這些裝載機有不同的換裝部件。當裝上鏟斗或抓斗時,可用語裝卸松散和小塊物料,叉架機構(gòu)使這些裝載機能適于把貨物舉升到一個不大的高度,有時也適于建筑安裝工程。</p><p>  因為叉車在硬路面上作業(yè),因此,主要用于倉庫并作為工廠物料的裝卸設(shè)備。這些裝載機是根據(jù)卡車的原理制造的,所以也叫卡車裝載機,他們以內(nèi)燃機或帶有蓄電池的電動機為動力。</p><

25、;p>  以發(fā)動機為動力的卡車用于大型倉庫和材料搬運工作,用于一般的堆放場和車輛裝卸。液力變距傳動系統(tǒng)使運動平穩(wěn)。還可以選配動力轉(zhuǎn)向及全天候駕駛室。</p><p>  單斗裝載機以履帶拖拉機或輪胎拖拉機作為行走機架。該裝載機可使裝載作業(yè)、建筑施工、安裝工程實現(xiàn)機械化。在這些換裝裝置中,主要附件是鏟斗。裝載設(shè)備有三種不同的形式,即前卸式、翻轉(zhuǎn)式和側(cè)卸式。前卸式機構(gòu)只允許從裝料的一側(cè)卸料;側(cè)卸式機構(gòu)是側(cè)面卸料

26、;翻轉(zhuǎn)式機構(gòu)則從后面卸料。</p><p>  目前,具有變量液壓驅(qū)動的工作裝置的前卸式裝載機使用得最為廣泛。</p><p>  多斗裝載機的產(chǎn)量比同一額定功率的單斗裝載機的產(chǎn)量高40%~60%。多斗裝載機適于磚廠、混泥土預(yù)制品廠及裝卸量大的火車站,也同樣適用于裝載松散物料。此外,該機還適用于對松散物料的顆粒分級,為此,可以安裝一個專用的振動篩。</p><p>

27、  用多斗裝載機為側(cè)邊卸料的平板車卸料,其效率很高。多斗裝載機可用于混凝土預(yù)制品廠的生產(chǎn)線中,也可用于筑路。在筑路中,用于將砂子和礫石裝入烘干筒和攪拌機里。</p><p>  該裝載機的工作機構(gòu)是兩個左右螺旋桿組成的螺旋給料器,安裝在斗式提升機的兩側(cè)。當給料器旋轉(zhuǎn)時,物料被送入各個鏟斗內(nèi),使得裝料比較容易。刮板固定在螺旋給料器的下方。多斗裝載機的提升機把物料卸在傳送帶上,再由傳送帶將物料運送到設(shè)備中。</

28、p><p>  有些裝載機用漏斗或料槽把物料送進運輸設(shè)備中。</p><p>  Pneumatic Motors and Tools</p><p>  Compressde air can be used for a wide variety of operations,such as:to drive air motors and air hammers,to o

29、perate air cylinders,to atomize liquids,to convery materials,to displace and agitate liquids,to serve as a cushion,to create a vacuum,to accelerate combustion,and to serve as a coolant and lubricant.</p><p>

30、  An electric motor is a device in which electrical energy is converted into mechanical energy.A fluid motor is a device for converting fulid energy into mechanical energy.In this chapter,the main features of pneumatic m

31、otors and pneumatic tools are discussed.</p><p>  GENERAL TYPES OF AIR MOTORS</p><p>  Air motors may be divided into tow general type: (1) the rotary type and (2) the reciprocating type. The co

32、mbination of a piston and cylinder is an example of the reciprocating type of motor.Two example of the rotary motor are the vane-type and gear-type motors.</p><p>  A rotary vane-type motor is illustrated.Th

33、e rotating member,with its sliding vanes,it is trapped between the vane(which ride on the inside of the housing)and pushes to the outlet.Thus the compressed air drives a rotating member.</p><p>  A gear-type

34、 motor is illustrated.A pair of meshed gears rotate inside a housing,As the gears rotate,the air is trapped between the gear teeth and housing,and pushes from the inlet to the outlet.Thus the compressed air drives the ge

35、ars.</p><p>  CHARACTERISTICS OF AIR MOTORS </p><p>  An air motor operates safely in an explosive atmosphere,and has a low installation cost,a rapid acceleration,and a high starting troque.It i

36、s compact,and its cariable speed can be changed.</p><p>  A typical curve for torque versus speed(rpm)for a rotary-type air motor is illustrated.Air-motor speed can be caried,in small steps,from zero a maxim

37、um by varying the air flow to the motor.The air flow rate to the motor can be varied by means of a valve in the inlet compressed-air line.The pressure at the air motor inlet can be contolled with an adjustable pressure r

38、egulator in the air inlet line;thus torque can be controlled by means of the pressure regulator.An air motor can be arranged to be </p><p>  A curve for horsepower versus speed for a rotary-type air motor is

39、 shown.The power output is at a maximum between zero and maximum speed.Power output is proportional to the product of torque times angular or rotational speed(rpm).</p><p>  The speed,torque,and direction og

40、 rotation of an air motor can be controlled and adjusted to job requirements.For example,reversible air motors are used to turn or screm studs into castings,when assembling engines.The air pressure to the air motor is re

41、gulated,so that the air motor stalls when the stud is driven to the correct tightness.In this instance,the air motor starts off at high speed(very low torque),is quickly loaded so that it stalls,and is then reversed.An a

42、ir motor has no tendency to</p><p>  Air motors are available commercially in sizes ranging from 1/10 horsepower to 50 horsepower,and in speed ranging from 20 rmp to 75,000 rmp.</p><p>  GENERAL

43、 FEATURES OF PNEUMATIC TOOLS</p><p>  Pneumatic tools represent a large number of air-operated machines that are usually transported to a work area,rather than transporting the work to the tool(as in machini

44、ng some metals by machine tools).In many instances,the tool is either held entirely by the hands or guided and controlled by hand.The tool may be portable.In a manufacturing plant,the compressor.On an outdoor constructio

45、n job,the compressor may be portable.In a manufacturing plant,the compressor may be stationary.Air from the com</p><p>  In a typical rotary pneumatic tool,the air enters the tool handle,passes through a man

46、ually operated control valve,passes through the end plates,and enters a chamber of a vane-type air motor.The air pushes the rotor form the inlet to the outlet.At the outlet,the air is discharged into the atmosphere.The t

47、ypical rotary air motor possesses three to five blades,rotates at speeds of 4000 to 25,000 rpm,and develops up to 3 horsepower.A spindle fastened to the rotor drives a set of planetary reduction</p><p>  The

48、 piston-type air motor is used for tools when higher horsepower and slower speeds are desired,as in hoists and heavy-drills.</p><p>  The percussion or hammer-type air motor is found in chippers, riveters,an

49、d pavement breakers.In this type of machine,the air usually passes through an exhaust valve,and then is exhausted into the atmosphere.The piston is moved back and forth.On the driving stroke,the inertia of the piston pro

50、vides a hammer blow or impact to a drill,a chisel,or a bit.</p><p>  Compressed air permits the use of tools are relatively compact,light in weight,flexible,portable,and easy to operate.Pneumatic tools are u

51、sed on a very light assembly work and on heavy-duty constrution jobs.The speed and direction of rotation of air motors can be controlled quickly,and they can be adjusted to serve requirements by means of a control valve

52、which throttles the flow of compressed air to the motor.pneumatic motors do not have a tendency to become hot when they are overheated.An air </p><p>  Among the many applications and users of pneumatic tool

53、s are: agricultural equipment manufacturers, aircrafe manufacturers, ammunition depots, automotive shops and plants, bakeries, boiler shop, can factories, cement plants, coal mines, construction work, cotton mills, cut-s

54、tone plants, dairies, distilleries, forge shops, foundries and steel mills, furniture factories, many kinds of industrial plants, laundries, machine shop, mining, oil refineries, paper mills, quarries, railroads, road bu

55、ildin</p><p>  PNEUMATIC TOOLS</p><p>  From the point of view of application of pneumatic tools, two main classes of tools should be considered (1)air-operated portable tools, and (2)air-operat

56、ed rock drills.</p><p>  Portable tools</p><p>  This class of pneumatic tools include grinders, buffers, and sanders. A rotary vane-type air motor is usually used for tools of this type. They a

57、re available in a wide range of speed and power.</p><p>  Drill-A rotary vane-type air motor is usually used for drills, reamers, tappers, and stud setters. Drills and reamers are used for steel, wood, and o

58、ther materials. Some tools are reversible, with rotation possible in either direction, and tools are nonreversible. Drill speed can be caried by throttling the air supply to the drill. Portable drills powered by a vane-t

59、ype rotary air motor are used also for drilling any mineral substance that can be penetrated by an auger or a tungsten carbied bit-</p><p>  Screwdrivers-A rotary vane-type air motor is usually used for scre

60、wdrivers, nut srtters, impact wrencher, and nibblers. Millions of nut, bolts, and screws, are driven daily by pneumatic tools in the large production plants making products,such as automobiles,refrigerator,radios,and va

61、rious appliances.pneumatic impact wrenches are used to remove or to tighten nuts by torsional or rotary impact,and pneumatic nibblers,and shears are used for cutting and sheathing steel metal.</p><p>  Hamme

62、r-In the penbmatic chipping hammer,a piston delivers a series of blows to a forming tool or chisel at the end of the hammer;the piston is air operated. The two type of percussion tool are the valve type and the vavele

63、ss type. In the valve type,a avlve arrangement is used to contral the flow of air both to and from the two ends of the hammering piston. In the valveless type, the valve action is performed by the piston . sand rammers

64、are actually pneumatic hammers; they are used for packi</p><p>  Hoists –hoists that are by compressed air are used in in many application, especially in machine shops and fundries. Pneumatic hoists are used

65、 outdoors and where fumes and explosive gases are present. An air motor is variable in speed, reversible in direction,and can withstand stalling form an overload without damage.</p><p>  Rock drills and pavi

66、ng breakers The second class of air-operated tools include various types of rock drills and pavement breakers.the hammers drills is commonly used air-operated tool in mining and genera excavation work. A piston can be fu

67、nd inside the air cylinder, and a-drill steel in used. The drill steel is provided with a shank on one end and a bit at the other end . the freely moving piston hammers or strikers rapid blows on the shank of the drill s

68、teel.</p><p>  Paving breakers are hand-operated pneumatic tools that have a wide variety of uses in industrial plants and in general construction work. One type of tool is valveless;another type is valve op

69、erated.</p><p>  One class of pneumatic tools is sometimes designated as pneumatic specialty tools. They include:staybolt riveters, paint mixers, screw spike drives,wire-wrapping decices, spinner riveters, s

70、hank grinders, reciprocating filing machines, valve grinders, staybolt tappers, air cranking motors,cut-off machines, concrete vibrators,countersinking tools, clip squeezers, tirevalve inserters, multiple screwdrivers an

71、d core-knockout machines. </p><p><b>  氣動馬達及工具</b></p><p>  壓縮空氣可實現(xiàn)多種多樣的操作,例如:驅(qū)動氣動馬達和氣錘,驅(qū)動氣缸,使液體霧化,傳送物體,移動和攪拌液體,當作氣彈簧,產(chǎn)生真空,加速燃燒,還可以用做冷卻劑,和潤滑劑。</p><p>  電動機是一種把電能轉(zhuǎn)換為機械能的

72、裝置。液壓馬達是一種把流壓能轉(zhuǎn)換為機械能的裝置。在本章中,將討論氣動馬達及氣動工具的主要特點。</p><p><b>  氣動馬達的類型</b></p><p>  氣動馬達分為兩種類型:(1)旋轉(zhuǎn)式;(2)往復(fù)式。例如往復(fù)式的馬達是由一個活塞和一個缸體組成的。而旋轉(zhuǎn)式馬達有兩個種類:葉片型和齒輪型馬達。</p><p>  葉片式旋轉(zhuǎn)馬達的

73、轉(zhuǎn)子和滑動葉片安裝在殼體中,在葉片之間形成空腔(葉片頂著殼體內(nèi)表面),空氣從輸入口進入該空腔,向出口方向擠壓推動葉片,從輸出口排出。于是壓縮空氣帶動轉(zhuǎn)子旋轉(zhuǎn)。</p><p>  齒輪式馬達,是利用一對齒和齒輪在殼體內(nèi)旋轉(zhuǎn)來工作的。隨著齒輪的轉(zhuǎn)動,空氣在齒輪與殼體間被擠壓,有進氣口進入,出氣口排出。壓縮空氣驅(qū)動齒輪轉(zhuǎn)動。 </p><p><b>  氣動馬達的特點</b&

74、gt;</p><p>  氣動馬達可以在易爆的空氣中安全工作,并且具有安裝成本低,加速快速,啟動轉(zhuǎn)矩大的特點。它簡單緊湊,可以改變轉(zhuǎn)速。</p><p>  研究旋轉(zhuǎn)式氣動馬達的轉(zhuǎn)矩-速度曲線;氣動馬達的速度是可變的,通過改變流入馬達的空氣量,可以實現(xiàn)從零到最大值無(?。┘壵{(diào)速。通過調(diào)節(jié)入口處的閥門可以調(diào)節(jié)空氣流入馬達的速度。馬達內(nèi)的壓力有入口處的壓力調(diào)節(jié)閥調(diào)節(jié)。氣動馬達通過四通閥調(diào)節(jié),

75、速度方向是可逆的。隨著負荷的增加,速度逐漸減小。氣動馬達可以停止而不會有一點損壞。</p><p>  研究旋轉(zhuǎn)式氣動馬達功率-速度曲線:輸出功率在速度為零到最大之間取得最大值。輸出功率等于轉(zhuǎn)矩乘以角速度或回轉(zhuǎn)速度。根據(jù)工作的需要可以調(diào)節(jié)與控制氣動馬達的速度、轉(zhuǎn)矩和旋轉(zhuǎn)的方向。例如,當組裝機器時,可逆氣動馬達可以用來旋轉(zhuǎn)安裝鑄件的螺釘。輸入氣動馬達的氣壓是可調(diào)節(jié)的,所以當螺釘?shù)臄Q緊力達到一個恰當值時,氣動馬達就停

76、止。在這個例子中,氣動馬達開始時轉(zhuǎn)速很高(低轉(zhuǎn)矩),快速加載,快速停止,然后反向旋轉(zhuǎn)。當過載時,氣動馬達不易發(fā)熱;氣動馬達能耐得住反復(fù)停止及反轉(zhuǎn)而不受損害或過熱。氣動馬達加速速度,因為壓縮空氣能以很高的速度被釋放。</p><p>  商用馬達的型號功率范圍從1/10馬力(1馬力=735.5W)至50馬力,速度范圍從20rpm到75000rpm。</p><p><b>  氣動

77、工具的一般特點</b></p><p>  氣動工具是大量氣動操縱機器的代表,通常這些機器傳遞動力到工作位置,而不是傳遞到其他工具(就如用機械工具進行金屬加工那樣)。在許多例子中,這些工具完全是手持的,或者手動控制。這些工具可以離空壓機有一定的距離。在戶外建筑施工時,空氣壓縮機是便攜的。而在制造工廠中,空壓機是固定的。空壓機中的空氣是由分配管通過過濾器、壓力調(diào)節(jié)器和潤滑器來供給的。來自潤滑器的空氣通過

78、靈活的軟管供給氣動工具。供給啟動工具的壓縮空氣的表壓力通常是每英寸90磅。氣動工具具有三大類:(1)旋轉(zhuǎn)式;(2)活塞式;(3)沖擊式。</p><p>  在典型的旋轉(zhuǎn)式氣動工具中,空氣進入手柄,經(jīng)過手動操作法,通過后擋板,進入到葉片式氣動馬達的腔體內(nèi)??諝鈴娜肟谶M入帶動轉(zhuǎn)子到達出口,出口的空氣進入大氣。典型的旋轉(zhuǎn)式氣動馬達有3-5個葉片,轉(zhuǎn)子速度在4000到25000rpm之間,功率可達到3馬力。固定在馬達轉(zhuǎn)

79、子上的軸驅(qū)動行星減速齒輪,使輸出軸的速度為需求的值。輸出軸可以配備卡盤,與鉆機、研磨機或其它機械相連接。</p><p>  在起重機和重型鉆機中,需要大功率低轉(zhuǎn)速,可用活塞式氣動馬達。</p><p>  沖擊式或氣錘式氣動馬達主要應(yīng)用于切削、打鉚機、路面破碎機。在這類機械中,壓縮空氣通常進過手柄,控制閥,進入到往復(fù)式活塞的缸體中,再通過排氣閥,然后排到大氣中去。活塞前后往復(fù)運動。在工作

80、沖程,活塞的慣性產(chǎn)生沖擊推力傳給鉆頭、鑿子或釬子。</p><p>  壓縮空氣可以保證使用工具相對緊湊,總量輕,靈活,易于攜帶,易操作。氣動工具可以運用于輕載的裝配作業(yè)和重型的施工作業(yè),根據(jù)需要通過控制閥來調(diào)解氣動馬達的速度和旋轉(zhuǎn)方向,控制閥通過節(jié)流口控制進入氣動馬達的壓縮空氣量。當過熱工作時,氣動馬達不易發(fā)熱。氣動馬達在易爆環(huán)境中不產(chǎn)生火花;因此,能應(yīng)用于煉油廠和其它有易爆問題的工廠。因為氣動馬達沒有電擊的危

81、險,它還能在潮濕的環(huán)境中工作。</p><p>  氣動工具有很多用途,如:農(nóng)業(yè)機械制造業(yè)、飛機制造業(yè)、軍用倉庫、流動車間和工廠、面包房、鍋爐間、罐頭廠、水泥廠、化工廠、煤礦、建筑施工、棉加工廠、碎石廠、乳品廠、釀酒廠、鍛造廠、鑄造鋼廠、家具廠、各種工業(yè)工廠,洗衣店、機械廠、采礦廠、煉油廠、造紙廠、采石廠、鐵道廠、筑路廠、橡膠廠、鋸木廠、船塢和造船場、熔煉廠、建筑工地和水下作業(yè)。</p><p

82、><b>  氣動工具</b></p><p>  從應(yīng)用方面來看氣動工具,有兩種主要的類型:(1)壓縮空氣驅(qū)動的便攜工具;(2)壓縮空氣驅(qū)動的巖石鉆。</p><p><b>  便攜工具</b></p><p>  這類氣動工具包括:磨削工具、鉆具、螺絲起子、氣錐、打鉚機和卷揚機。</p><

83、p>  磨削工具:磨削工具包括研磨器、打磨器和沙光機。這類工具常用旋轉(zhuǎn)式葉片氣動馬達,他們運用于速度和功率范圍大的場合。</p><p>  鉆具:旋轉(zhuǎn)式葉片氣動馬達適應(yīng)于鉆具、鉸刀、敲打和螺絲安裝。鉆具和鉸刀適用于鋼、木或其它材料加工。某些工具式可雙向的,轉(zhuǎn)子的旋轉(zhuǎn)方向式任意的,而這些工具式不可逆雙相旋轉(zhuǎn)的。通過節(jié)流控制進入鉆具的空氣可以改變鉆具的速度。便攜式鉆具由葉片式旋轉(zhuǎn)氣動馬達提供動力,它的螺紋鉆頭

84、可以用于穿透任何材料,例如,碳化鎢釬頭用于煤炭、白堊、頁巖和硬質(zhì)地層。</p><p>  螺絲起子:旋轉(zhuǎn)式氣動馬達應(yīng)用于螺絲起子、螺絲調(diào)節(jié)、沖壓扳手、下料機等。每天在大量的制造產(chǎn)品諸如汽車、冰箱、收音機和各種各樣器具上,成百萬的螺母、螺栓和螺釘?shù)扔脷鈩庸ぞ邅戆惭b。氣動扳手通過扭力或旋轉(zhuǎn)沖擊來拆卸或著擰緊螺母,氣動下料機和剪床用來切割或剪斷金屬。</p><p>  氣錘:在氣動錘中,活塞

85、把連續(xù)的錘擊力傳遞到前端的工具或錘端的鑿子上;活塞式空氣操縱的。有二類沖擊式工具:有閥型和無閥型。在有閥型中,閥用來控制進出活塞兩端的空氣;在無閥型中,閥的作用由活塞來完成。沙錘實際上式氣動錘,它們應(yīng)用于鑄造車間沙模成型。</p><p>  升降機:由壓縮空氣操縱的升降機有很多應(yīng)用,特別式在機械廠和鑄造車間。氣動升降機適用于戶外和有煙霧及易燃易爆氣體的環(huán)境下。氣動馬達的速度可以調(diào)整,轉(zhuǎn)向是可以變化,且在過載時能

86、停止工作而不受損壞。</p><p><b>  巖石鉆和風鎬</b></p><p>  第二種類型的氣動工具包括各種類型的鉆石機和風鎬。在開采和挖掘工作中,常用的氣動工具是沖擊鉆。氣缸內(nèi)有活塞和鉆桿。鉆桿的一端是柄,另一端是鉆頭。活塞自由快速移動或快速撞擊作用于鉆頭鋼桿的柄上。</p><p>  風鎬是人工操縱的氣動工具,在工廠和工地有多

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