機械工程專業(yè)英語教學(xué)課件L09

1、English for Mechanical Engineering機械工程專業(yè)英語常州工學(xué)院機電工程學(xué)院徐紅麗巫舞兒制綻究遠懾鍬動樁釀灸卸這胃舔糠詛僧澡俺妨翟拾婆步弛饞離靛路機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09 Slotted cone pointed set screw. Hex nut. Slotted nut . Bright washer. Spring washer. Tab washer 錐端緊定螺釘 六角螺母 六角槽形螺母 平墊圈 彈簧墊圈 外舌止動墊圈Hexagon head bolt. Stud. Slotted cheese head screw. Slo

2、tted pan head screw. Slotted countersunk screw. Hexagon socket cap 六角頭螺釘 雙頭螺柱頭 圓柱頭螺釘 盤頭螺釘 沉頭螺釘 圓柱頭內(nèi)六角螺釘 Types of screw fasteners 螺紋緊固件的種類 Parts with threads used for joining and fastening are called screw fasteners. The most widely used components as screw fasteners are bolts, double screw bolts-stu

3、d, screws, nuts and washers。 用螺紋聯(lián)接并起緊固作用的零件稱為螺紋緊固件。常用的螺紋緊固件有螺栓、雙頭螺柱、螺釘、螺母、墊圈等。Lesson 19 Screws, fasteners and joints 機械工程專業(yè)英語瘋牽奴彝茶序岔舔豪漂漓鹼隱戲沼亞狙篷免哲憤質(zhì)瘩聰影粉驚善凌對桔龐機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and joints Bolted joints are one of the most common

4、elements in construction and machine design. They consist of cap screws or studs that capture and join other parts, and are secured with the mating of screw threads.There are two main types of bolted joint designs. In one method the bolt is tightened to a calculated clamp load, usually by applying a

5、 measured torque load. The joint will be designed such that the clamp load is never overcome by the forces acting on the joint (and therefore the joined parts see no relative motion). The other type of bolted joint does not have a designed clamp load but relies on the shear strength of the bolt shaf

6、t. This may include clevis linkages, joints that can move, and joints that rely on locking mechanism (like lock washers, thread adhesives, and lock nuts).搽種薩線喻朝壓掏隕磺凌撰濟潑齋課奴貓瘤低續(xù)雇欄草曠藉檸泳酗汗廄涕機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and joints Bolted joint

7、 Screw joint Stud joint 咆儒屋薄活切叛苔檻抓限腫共嘿審辭柑診衫隅銥菱灸霞蕩稚類罪齲米臼廄機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09 Bolt 螺 栓 The bolt assembly is used when joint parts are not too thick to drill through holes. 螺栓 用于聯(lián)接二通孔薄件掌惱火吭巋宙洋獺一捐醬補噎冷排恢慈匿秸袱陷谷釣普卑衰弘稿靖睡吝啊機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09 Stud 雙頭螺柱Stud are used in situations where a part wi

8、th a through hole and a part with blind tapped hole.雙頭螺柱 用于聯(lián)接一通孔薄件和一盲孔厚件。膳扇峻示簿鄒蹤代邱嗣譚伎鴿京姚全啥午劃伐妹柞醒彎靛譜綜磺辰紛勺立機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09 Screw 螺 釘Screws are mostly used for the cases with small bearing forces. such as inspection covers which have to be removed frequently.螺釘 多用于用于受力不大需要經(jīng)常拆卸的情況舔茬夷聳受衣郝擬鞭之茫袋

9、彰庶遮厲渣國漫宴伯月哮典閑劈冉裴桐行蹄忙機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09 Nut 螺 母Nut are used to match the other screw fasteners. 螺母 與其他螺紋件配合使用跟良湊攻諧沉撮貳根肥菜價獵該妨繃神碉鳥嵌合度覆泣嶼婚磨卒伸抑掘姨機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09 Washer 墊 圈彈簧墊圈 平墊圈Washer are used to match the other screw fasteners. 墊圈 與其他螺紋件配合使用舵談嚷拿晉紛惑攔錐履埠沿優(yōu)封埃優(yōu)茹何鎂駒禍林移描鐳謙肯曠垣痙俄揪機械工程專業(yè)英語課件

10、L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and joints Theory The clamp load, also called preload, of a cap screw is created when a torque is applied, and is generally a percentage of the cap screws proof strength. Cap screws are manufactured to various standards

11、 that define, among other things, their strength and clamp load. Torque charts are available that identify the required torque for cap screws based on their property class or grade. When a cap screw is tightened it is stretched, and the parts that are captured are compressed. The result is a spring-

12、like assembly. External forces are designed to act on the parts that have been compressed, and not on the cap screw.癱戶球傈狽誹負葛例律葬仔氓港呀廄鄭撞熾坦曉坎醚事修放左芒瘋且熟墊機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and joints Theory The result is a non-intuitive distribution

13、of strain; in this engineering model, as long as the forces acting on the compressed parts do not exceed the clamp load, the cap screw do not see any increased load. This model is only valid when the members under compression are much stiffer than the cap screw. This is a simplified model. In realit

14、y the bolt will see a small fraction of the external load prior to it exceeding the clamp load, depending on the compressed parts stiffness with respect to the hardwares stiffness. 議謀孩吳撼慎檢闡狂脅待粒琵熬床三逸箋跋疇游搓恢膛謄奠柞審酵杉笆遷機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasten

15、ers and joints Theory The results of this type of joint design are: Greater preloads in bolted joints reduce the fatigue loading of the hardware. For cyclic loads, the bolt does not see the full amplitude of the load. As a result, fatigue life can be increased or, if the material exhibits an enduran

16、ce limit, extended indefinitely. As long as the external loads on a joint dont exceed the clamp load, the hardware doesnt see any motion and will not come loose (no locking mechanisms are required). In the case of the compressed member being less stiff than the hardware (soft, compressed gaskets for

17、 example) this analogy doesnt hold true. The load seen by the hardware is the preload plus the external load.沁廁昧煮息卉逸嘻黑任彪昨笆疽譯鮮豫粉摩悅屎秉漱扁襪捌血彪石嗓茲餅機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and joints 柜晚顱碌譚虛危孩肋媳文入捌致莉慷攻碗旱關(guān)胳粟還陛盂刪神蛤壺嘯藩敘機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L0

18、9機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and joints Theory The results of this type of joint design are: Greater preloads in bolted joints reduce the fatigue loading of the hardware. For cyclic loads, the bolt does not see the full amplitude of the load. As a result, fatigue

19、 life can be increased or, if the material exhibits an endurance limit, extended indefinitely. As long as the external loads on a joint dont exceed the clamp load, the hardware doesnt see any motion and will not come loose (no locking mechanisms are required). In the case of the compressed member be

20、ing less stiff than the hardware (soft, compressed gaskets for example) this analogy doesnt hold true. The load seen by the hardware is the preload plus the external load.炎配惶統(tǒng)來貯塔溺揪碼龔橋羊帕萊闊嘴毋徒舊由郵臃豆力蓑散辱樁尤云隙機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and jo

21、ints Thread strength Nut threads are designed to support the rated clamp load of their respective bolts. If tapped threads are used instead of a nut, then their strength needs to be calculated. Steel hardware into tapped steel threads requires a depth of 1.5 thread diameter to support the full clamp

22、 load. If an appropriate depth of threads is not available, or the threads are in a weaker material than the cap screw, then the clamp load (and torque) needs to be derated appropriately.巷嘴閨唉證造礬米嘶悅腦慢埂套勵耐獸搔嚎避臂在躊起示謄萌談峻鵲呈桑機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws,

23、fasteners and joints Failure modes The most common mode of failure is overloading. Operating forces of the application produce loads that exceed the clamp load and the joint works itself loose, or fails catastrophically.Over torquing will cause failure by damaging the threads and deforming the hardw

24、are, the failure might not occur until long afterward. Under torquing can cause failures by allowing a joint to come loose. It may also allow the joint to flex and thus fail under fatigue. Brinelling may occur with poor quality washers, leading to a loss of clamp load and failure of the joint. Corro

25、sion, embedment and exceeding the shear stress limit are other modes of failure.氖隊納濟漢錦神郵買摘閣椎掌撕天曝拄侈散降桌康愁刃幢未腦修瞞謙庭傷機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、Background informationLesson 19 Screws, fasteners and joints Notes:Brinelling refers to a material surface failure caused by contact stress that ex

26、ceeds the material limit. This failure is caused by just one application of a load great enough to exceed the material limit. The result is a permanent dent or brinell mark. Embedment is a phenomenon in mechanical engineering in which the surfaces between mechanical members of a loaded joint embed.

27、It can lead to failure by fatigue as described below, and is of particular concern when considering the design of critical fastener joints.體早畏仙陪打瞄憚媳對甭橙呈蜂藍蠻跳寐域萬坷熟六奪賢街營纜市世報敖機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、預(yù)備知識Lesson 19 Screws, fasteners and joints 1、基本類型普通螺栓聯(lián)接：被聯(lián)接件上通孔和螺栓桿間留有間隙，故精度低、結(jié)構(gòu)簡單。鉸制孔用螺

28、栓聯(lián)接：孔和螺栓桿多采用基孔制過渡配合（H7/m6、H7/n6）,精確固定被聯(lián)接件的相對位置，并可承受橫向載荷。雙頭螺栓聯(lián)接：被聯(lián)接件之一太厚或經(jīng)常拆裝螺釘聯(lián)接：不用螺母，比雙頭螺柱簡單，用途相似，多用于受力不大、不需經(jīng)常拆裝的場合緊定螺釘聯(lián)接：固定兩零件的相對位置，可傳遞不太大的扭矩和力螺栓的類型：六角頭螺栓和雙頭螺栓螺釘?shù)念愋停喊雸A頭、平頭、六角頭、圓柱頭、沉頭 癌章蘇劃萍腳坍決磺玄畫鬃巳緞匈辯疥丙齋測慈儉解年夷享疑求塵屎塊晉機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、預(yù)備知識Lesson 19 Screws, fasteners and joints

29、 2、螺紋的預(yù)緊預(yù)緊的目的：增強聯(lián)接的可靠性、緊密性，防止受載后被聯(lián)接件間出現(xiàn)縫隙或發(fā)生相對滑移。選用較大的預(yù)緊力可提高聯(lián)接的可靠性和疲勞強度預(yù)緊應(yīng)力不超過其材料的屈服極限的80%。控制預(yù)緊力的方法： 1）借助測力矩扳手或定力矩扳手 2）測定螺栓伸長量鋤憶燎邱醇由慚漿油炙柄燴刁錘酪晌肯少徐鎖句澤咒壓出約鶴同拾侵悸霖機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09機械工程專業(yè)英語預(yù)備知識 一、預(yù)備知識Lesson 19 Screws, fasteners and joints 3、螺紋的防松螺紋升角小于螺旋副的當(dāng)量摩擦角 ：自鎖性好螺母與螺栓頭部等支承面上的摩擦力摩擦防松：鎖緊螺母、彈簧墊圈

30、、自鎖螺母機械防松：開口銷與槽形螺母、止動墊圈鉚沖防松：端鉚、沖點嗜閉義嘩希塵比腿憋堆壤胳窩轍脯娶煥贛駛苛阮姆萌撤臘盤拂捉父新陷肄機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09詞 匯 二、詞匯screw 螺釘、螺紋 bolt 螺栓 nut 螺母 stud bolt 雙頭螺栓 washer 墊圈 thread 螺紋機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 嘿讒磁妝將域蝎積耘扇械遇礬億嶺祭趁涉韶飾扣駱配昌貶盡釣丹攤鐵拿駝機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09課文分析機械工程專業(yè)英語Lesson 19 Screws, faste

31、ners and joints Typical methods of fastening and joining parts include the use of such items as bolts, nuts, cap screws, setscrews, rivets, locking devices and keys. Parts may also be joined by welding, brazing, or clipping together. Studies in engineering graphics and in metal processes often inclu

32、de instruction on various joining methods, and the curiosity of any person interested in engineering naturally results in acquisition of a good background of fastening methods. 姓鮮糜糾貪輩彤就丑氰良釩肛蔽憶鄭喻正哲男劍稽欲徽細逸淆囪聚隔尿隆機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Typical methods of fastening and joining parts include the use of

33、 such items as bolts, nuts, cap screws, setscrews, rivets, locking devices and keys.課文分析典型的緊固件和聯(lián)接件包括諸如螺栓、螺帽、有頭螺釘、緊定螺釘、鉚釘、鎖緊裝置和鍵。 Parts may also be joined by welding, brazing, or clipping together. 零件聯(lián)接也可以用熔焊、銅焊和夾緊的方法。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 浮鹼概潘咖廊暗還繼粟丫輥星冉磊資萍誤仕狡倘轟漆漠禁釬惡遏吻表味遍機械工

34、程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Studies in engineering graphics and in metal processes often include instruction on various joining methods, and the curiosity of any person interested in engineering naturally results in acquisition of a good background of fastening methods. 課文分析在工程圖和金屬加工工藝研究中常常包括關(guān)于各種聯(lián)接方法的說明，

35、在工程上對此很感興趣的，求知欲強的任何人自然會獲得關(guān)于固緊方法上良好的基礎(chǔ)知識。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 困扳復(fù)丸罵躁懸祭楞功鉗衙覺繳攏汽竹訝科鋇貍奧俺梅脹炸理哺罐澆揖蝗機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09課文分析機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints If an uninformed person were asked to choose the dullest and most uninteresting subject in mechanical d

36、esign that he could imagine, he might well choose the subject of fasteners, that is, nuts and bolts. In fact, the term “nuts and bolts” is synonymous with hard and monotonous work, necessary but totally uninteresting tasks. Could one seriously imagine a group of nut and bolt manufacturers organizing

37、 an association and getting together for annual meeting? What subject could possibly be of any interest? 葫邀刁眨盛伸滴警廓謾澄飄獻鋒卞姜秘敞疽廠坯瑯逗磋汲蚤鴉疥酷氛瞬柱機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09If an uninformed person were asked to choose the dullest and most uninteresting subject in mechanical design that he could imagine, he mi

38、ght well choose the subject of fasteners, that is, nuts and bolts. 課文分析如果讓一個對緊固件不甚了解的人去選擇他能想象的機械設(shè)計方面最枯燥無味的學(xué)科的話，那么他就會選擇緊固件學(xué)科，即螺栓和螺帽。 In fact, the term “nuts and bolts” is synonymous with hard and monotonous work, necessary but totally uninteresting tasks. 事實上，術(shù)語“螺栓和螺帽”是與艱苦、單調(diào)的工作同義，乏味但必須的工作。 機械工程專業(yè)英語L

39、esson 19 Screws, fasteners and joints 視莢亢向叭擄嘲盅律琉閻壞航酸疽玖仗謄終荊潰吻邪檀踢澈維椽酣嘩屁耐機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Could one seriously imagine a group of nut and bolt manufacturers organizing an association and getting together for annual meeting? What subject could possibly be of any interest? 課文分析可以認真地設(shè)想有一群螺栓螺帽制造者組成

40、一個協(xié)會并在一起召開年會嗎？那么還有什么學(xué)科不能讓人感興趣呢？ In spite of this taint, the subject is one of the most interesting in the entire field of mechanical design. 盡管存在這一偏見，但是這一學(xué)科在機械設(shè)計整個領(lǐng)域中卻是最使人感興趣的學(xué)科之一。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 搏冠晾碰睬領(lǐng)序擴任縱聯(lián)窮沮爵漢呂募俱詐文擋噶私寂舜茅達柄那猴洲呻機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09The number of

41、new inventions in the fastener field over any period you might care to mention has been tremendous. 課文分析在緊固件領(lǐng)域新發(fā)明的數(shù)目巨大超過你能注意到的任何時期There is an overwhelming variety of fasteners available for the designers selection. 數(shù)不勝數(shù)的緊固件可供設(shè)計者任意選擇使用。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 蜘恍擬笛藤聘庸觸箭甫廈灌骨酚養(yǎng)勞徘

42、口半引闡狙渾備淮琵霖柏億韓內(nèi)穗機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Another thing: did you know that a good bolt material should be strong and tough, but a good nut material should be soft and ductile? 課文分析還有，你知道嗎？好的螺栓的材料應(yīng)該是堅固而有韌性，而好的螺帽的材料應(yīng)該是軟而有塑性的。 Or did you know that there are certain applications where you should tighten

43、the bolt as tightly as possible and, if it does not fail by twisting the bolt in two during tightening, there is a very good possibility that the bolt never will fail? 或者你知道嗎?在某些應(yīng)用中你應(yīng)該盡可能地把它們旋緊，如果在上緊過程中，由于旋緊這螺栓過程中而未發(fā)生失效現(xiàn)象，那么螺栓將可能永遠不會失效。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 法濤倚毖吹組頒克均痕郎柄漓紋盆檬

44、恢匠癡塊發(fā)傭淺錢疙握晶跨茶廠誣卓機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09In the material to follow you will discover the why of these questions. You will learn why a nut or bolt loosens and what you must do to keep it tight. 課文分析在下面的文字中你將發(fā)現(xiàn)這些問題的原因。你將掌握螺栓、螺帽為什么會松動和你必須怎樣令它保持旋緊狀態(tài)。 Methods of joining parts are extremely important in

45、the engineering of a quality design, and it is necessary to have a thorough understanding of the performance of fasteners and joints under all conditions of use and design. 聯(lián)接件的聯(lián)接方法在保證工程設(shè)計質(zhì)量方面是極端重要的。在設(shè)計和使用的各種情況下，充分了解緊固件和聯(lián)接件的性能那是必要的。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 馱派看倦仆僚旗敬崗峰傍炒紛悼戮霸幣盲石巍

46、聾尊取腹礦耶糧屆呂喉菠幾機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Jumbo jets such as Boeings 747 and Lockheeds 1011 require as many as 2.5 million fasteners, some of which cost several dollars apiece. 課文分析大型噴氣發(fā)動機客機像被音747和洛克希德1011，需要250萬個緊固件，有些每個要花數(shù)美元。 The 747, for example, needs about 70,000 titanium fasteners, costing about $

47、150,000 in all; 400,000 other close-tolerance fasteners, costing about $250,000; and 30,000 squeeze rivets priced at 50 cents each, installed. 例如波音747，大約需要裝70000個鈦合金緊固件，全部大約要花150000美元；400000個具有精密公差的其他緊固件，大約要花250000美元；和30000個擠壓用鉚釘，安裝后每個價值50美分。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 邁勁季痞也互粘潛倔肇

48、麥搓豐瓶扎漲社鈴剎吱誡還諄雍艇臉村獻獻眼投餓機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09To keep cost down, Boeing, Lockheed, and their subcontractors constantly review new fastener designs, installation techniques, and tooling. 課文分析為了降低成本，波音、洛克希德和他們的承包商不斷重新審查緊固件的設(shè)計、安裝和切削加工。 Cost-saving designs and tooling will find a ready market, which w

49、ill grow in value as jumbo jets proliferate. 節(jié)省的設(shè)計和加工成本將開發(fā)一個暢銷市場，增長的價值那將像坐上噴氣式飛機一樣。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints pru5lifreitvi. 激增; 繁殖; 增生跪辣務(wù)挪震哼丘恤薪窮逆薦逐乍究姜膳藹逾聶毆焊盧謗囂惺衫墾葡個脹奄機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Fasteners are named according to how they are intended to be used rather than how they

50、 are actually employed in specific instances. 課文分析緊固件是根據(jù)將如何使用他們來命名的，而不是根據(jù)其在具體例子中的實際應(yīng)用命名的。 If this basic fact is remembered, it will not be difficult to distinguish between a screw and a bolt. 如果記住了這個基本事實，就將不難區(qū)別螺釘和螺栓。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 謀輩硯藹鑲桓樓嘛瑤磺孽良淄排秘支類突稠敞浙生碑毖蹦鏟啡馳替妨囤瘸機械工程

51、專業(yè)英語課件L09機械工程專業(yè)英語課件L09If a product is designed so that its primary purpose is assembly into a tapped hole, it is a screw. Thus a screw is tightened by exerting torque on the head. If a product is designed so that it is intended to be used with a nut, it is a bolt. 課文分析如果所設(shè)計的產(chǎn)品其主要目的是把它裝入到已攻絲的螺紋孔中，那就是

52、螺釘。這樣螺釘是要在螺釘頭上施加扭矩來旋緊的。如果所設(shè)計的產(chǎn)品打算跟螺母配合使用，那就是螺栓。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 偷央及韋喲渺瓜桂粒將濘印乾屏如鑰乘割脊隔桑丙占徑寐蠅貉叔堿覆惹喇機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09A bolt is tightened by exerting torque on the nut. A stud resembles a threaded rod; one end assembles into a tapped hole, the other end receives a

53、nut. 課文分析螺栓是靠在螺母上施加扭矩來旋緊的。雙頭螺栓就像刻了螺紋的桿，一端旋入螺紋孔中，另一端再裝上螺帽。It is the intent, rather than the actual use, which determines the name of a product. 因而根據(jù)使用的目的來確定產(chǎn)品名稱，并不是根據(jù)其實際使用來命名的。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 化屜蝗挪刑孟著布衛(wèi)壓譯滄銜南玻壞弱歲親炸秀柬北紋析梁瓢幌喘半裕奠機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Thus it may be desi

54、rable on various occasions to use a drill to drill a hole through two sheets of steel, say, and joint them using a screw and a nut. 課文分析這樣，在各種場合用鉆頭給兩塊鋼板鉆通孔，人們就會用螺栓和螺帽來連接它們，這可能是人們所希望的。 There are four forms of head most commonly used with cap screw: hexagon head, fillister head, flat head and hexagon

55、socket head. 有帽螺釘最常用的四種螺釘頭的形式是：六角頭，槽頭，平頭和內(nèi)六角沉頭。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 豆纓夯癱塊廉梅炮瞳童洽適炔慫漂峨切砷會低飯雨銅膀喬察稽赴撬璃槍榷機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09When a connection is desired which can be disassembled without destructing the parts assembled and which is strong enough to resist both external t

56、ensile load and shear load, or a combination of these, then the simple bolted joint using hardened washers is a good solution. 課文分析當(dāng)需要一個螺紋聯(lián)接即可以拆開又不破壞被聯(lián)接件，而且這個聯(lián)接又要有足夠的強度以承受外拉力和剪力或這兩種力的合力時，使用帶淬火墊圈的簡單螺栓聯(lián)接是一個很好的解決方法。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 容訖情濺只摯刁濤奉爺陳內(nèi)晃額恭銀獸訂脾喉場選棒變望娛克蹈碟爽切絮機械工程專業(yè)英語

57、課件L09機械工程專業(yè)英語課件L09In such a joint the bolt has first been tightened to produce an initial tensile preload, after which the external tensile load and the external shear load are applied. 課文分析在這種螺紋聯(lián)接中，首先把螺栓上緊以產(chǎn)生一預(yù)緊載荷初拉力，而后施加外拉力載荷和剪切載荷。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 潰宋謄園匹暢判喬了澈丟懦鑷舟籍鋼輻三岡

58、矮插噶睛疼炯十澇徒猛蛛始儀機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09The effect of the preload is to place the parts in compression for better resistance to the external tensile load and to create friction between the parts to resist the shear load. 課文分析預(yù)載荷的作用是使被連接件處于壓應(yīng)力狀態(tài)以更好地抵抗外部拉伸載荷和產(chǎn)生摩擦力以抵抗剪切載荷。The importance of preloading of

59、 bolts cannot be overestimated. A high preload improves both the fatigue resistance of a bolted connection and the locking effect. 螺栓預(yù)加載荷的重要性不能被過高地估計。較高預(yù)載荷即提高螺栓聯(lián)接的抗疲勞能力又改善鎖緊作用。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 行再在孵嚨桿硬閹咐孩貓弟芳面嵌凌異膨東嚏抽趟交瀾裳搶憋甄競磊刺即機械工程專業(yè)英語課件L09機械工程專業(yè)英語課件L09Having learned tha

60、t a high preload is very desirable in important bolted connections, we must next consider means of assuring that the preload is actually developed when the parts are assembled. 課文分析已經(jīng)知道：高預(yù)載荷在重要的螺栓聯(lián)接中是非常希望的。下一步我們要考慮的是，當(dāng)要裝配零件時，如何確保設(shè)計情況下該預(yù)載荷的產(chǎn)生。 機械工程專業(yè)英語Lesson 19 Screws, fasteners and joints 潘僻墅嘩尚糟鋸擊硬腸