膜片弹簧的设计毕业论文英文资料翻译.doc

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1、 毕业设计（论文）英文翻译、年级、专业: 2008级机械设计制造及其自动化 姓 名: 学 号: 指 导 教 师: The design of diaphragm springAbstractThe clutch is the important components in automobile transmission system, the main function is to achieve is cut off and the engine to the power transmission, guaranteed that the automobile starts smoothly

2、, ensure drive system when the shift work smoothly and limit the transmission system to withstand the maximum torque, prevent the transmission system overload. Diaphragm spring clutch is in recent years in the vehicle and light vehicle used in a clutch, the torque capacity of large and relatively st

3、able, convenient operation, good balance, can be mass production, and the research on it has become more and more important. Keywords: diaphragm spring clutch;Diaphragm spring clutch overviewDiaphragm spring clutch is in recent years in the car and light truck used a clutch. Because of its as a pres

4、sure spring, can also play the separation lever effect, whereby the clutch in order to simplify the structure, quality reduction, and remarkably reduce the axial size of clutch. Secondly, as a result of diaphragm spring and pressure with the circumferential contact, so that uniform distribution of p

5、ressure. In addition due to the diaphragm spring with nonlinear elastic properties, it can be in the driven disc friction plate abrasion, spring can still reliably transfer the torque of the engine, without causing slip away from. Clutch, the clutch pedal manipulation of light, reduce the labor inte

6、nsity of the driver. In addition, because of the diaphragm is a symmetric parts, good balance, at high speed, the pressing force reducing rarely, but the week arranged elastic clutch at high speed, due to the centrifugal force will generate transverse bending, spring severe drum, thereby reducing th

7、e pressure plate pressure, thereby causing the clutch to transmit torque capacity. As can be seen, for light diaphragm spring clutch design research for the improvement of automobile clutch performance in all aspects has very important significance.As the hold-down spring called diaphragm spring, is

8、 made of spring steel stamped, with no bottom plate shape of the truncated cone shaped thin wall diaphragm, and the small end surface on a plurality of radial groove, to form an elastic lever, while the remaining slots cut end truncated conical part is a spring action. Diaphragm spring are arranged

9、on the both sides of the supporting ring, and the latter by means of a fixed on a clutch cover some ( radial grooves cut in half number of rivets to install location ). When the clutch cover bolt fixed to the flywheel, the flywheel clutch cover to the rear support ring, diaphragm spring to generate

10、elastic deformation, the apex angle of the cone becomes large, and even almost flattened diaphragm spring. At the same time the larger end of the diaphragm spring pressure plate pressing force generated on the clutch is in the coupling. When the clutch is disengaged, the separation bearing forward d

11、iaphragm spring pressure before the supporting ring as a fulcrum of reverse tapered transition, so that the diaphragm spring after the shift, and by separating the hook pulling the pressure shift clutch. Diaphragm spring clutch has many advantages: first of all, as a result of the diaphragm spring w

12、ith nonlinear characteristic, therefore the design of the friction plate abrasion, spring pressure is nearly constant, and can reduce the separation when the clutch pedal force, make the manipulation of light; secondly, diaphragm spring clutch mounted position on the center line of the shaft are sym

13、metrical, so the pressing force actually from the influence of the centrifugal force, stable performance, balance or; furthermore, diaphragm spring itself and pressing spring and separation of the clutch lever effect, simple structure, less number of parts, the quality decreases obviously shortens t

14、he axial dimension; in addition, the diaphragm spring and the pressure plate is the entire circumferential contact, so that the pressure uniform distribution, good contact friction friction plate, uniform, easy to achieve good ventilation and cooling.Pull type diaphragm spring clutch has the advanta

15、gesCompared with push, pull type diaphragm spring clutch has many advantages: a middle supporting components, and do not support ring or only a supporting ring, the structure is simple, compact structure, fewer parts, quality less; pull type diaphragm spring is central and the platen press platen si

16、ze in the same conditions the larger diameter diaphragm spring, improves the pressing force and the ability to transfer torque, and does not increase the pedal force, in the transmission of the same torque, can use the small size structure; in the joint or separate state, the clutch cover deformatio

17、n small, large stiffness, higher separation efficiency; pull leverage ratio greater than push-down lever ratio, and the intermediate support to reduce the friction loss, high transmission efficiency, pedal operated more portable, pull type pedal force than the push type general reduction; both in th

18、e joint state or separate state, pull type diaphragm spring clutch structure with cover support keeping in contact, on a supporting ring wear can not be formed after clearance and increased pedal free travel, no impact and cry; a longer service life.Clutch diaphragm spring designThe structural chara

19、cteristics of diaphragm springFrom the front can know, the design of the diaphragm spring compression spring is. The diaphragm spring clutch push and pull, in the design of the structure.Diaphragm spring in the shape of the structure is divided into two parts. In the larger end of the diaphragm spri

20、ng is an integrity of the frustum, it is shaped like a bottomless dishes and general machinery with disc spring disc spring are exactly the same, so as part of. Diaphragm spring on elastic effect is the dish spring part. Disc spring elastic effect is that: along the axial direction of loading, disc

21、spring compression becomes flat, after unloading and the restoration of the prototype of the. Can be said that the diaphragm spring disc spring is a special structural form. The difference is, the diaphragm spring is also arranged on the radial slotted section. On the diaphragm spring radially slott

22、ed portions like a ring of petals, its role is, when the clutch is disengaged as separation lever. So it is also called the separation claw. Separation claw and a disk spring component junction radial slot wide rectangular circular hole. In so doing, one can reduce the stress concentration at the ro

23、ot of the separation claw, on one hand and can be used for the placement of pins fixed diaphragm spring, separation claw root fillet transition R 4.5.Diaphragm spring deformation and loading methodAs a result of diaphragm spring used to push type structure, so the dress. In the engagement and diseng

24、agement of clutch, diaphragm spring loading situation is different, corresponding to two modes of loading and deformation:(1): when engaging clutch diaphragm spring up, pressing spring, the pressure plate in - clutch cover assembly and flywheel assembly previously, diaphragm spring approximation is

25、in free state, diaphragm spring on the platen without compressing function. When the platen - clutch cover assembly and flywheel mounted together, the front end of the flywheel clutch cover to the front end surface close. Therefore, the clutch cover through the supporting ring 4of the diaphragm spri

26、ng loaded, almost flat diaphragm spring. At the same time on the platen also effect of load. We call the pressing force. The supporting ring 4and a diaphragm spring plate contact between the height variation called big deformation of diaphragm spring release bearing, relative to the platen height va

27、riation called the small end deformation.(2): when the separation bearing separation with P2force acting on the diaphragm spring of the small end, a supporting ring 4is inoperative, and the supporting ring 5to play a role in. When the P2force reaches a certain value, diaphragm spring is pressed over

28、. Separation in the larger end of the diaphragm spring and the small end will further generate additional deformation and. The diaphragm spring deformation of 。The elastic deformation properties of diaphragm springIn front of said diaphragm spring on elastic part is the disc spring disc spring part,

29、 part of the elastic deformation and the spiral spring is not the same, it is a nonlinear spring, its characteristics and the disc spring portions of the original inner truncated cone high H and spring plate thickness ratio of H H/h. Different H/h values can be obtained by different characteristics

30、and deformation characteristics of. General can be divided into the following four cases:The H/h The following figure 7.1H/h=0.5 curve, the curve shape is: load P increases, deformation is always increasing. The stiffness of the spring is very big, can bear large load, and as a buffer device for str

31、oke limiter.The H/h =In Figure 7.1H/h=1.5 curve, elastic characteristic curve in the middle of a very straight, deformation increase, load P almost unchanged. This spring called zero stiffness spring.The H/h Figure 7.2 below, the spring characteristic curve with a greater negative stiffness unstable

32、 operating region, and a load negative area. This spring for automotive hydraulic transmission in thelocking. Figure 7.2 Three kinds of different H/h values dimensionless characteristic curve Figure 7.3 Three different kinds of H/h value of the dimensionless elastic deformation curveThe parameter de

33、termining the size of the diaphragm springIn the design of the diaphragm spring, general preliminary selected for their full size and then a series of calculation, finally selecting the most appropriate size. The structure diagram of figure R and R/r determinationThe ratio of R/r to the spring load

34、and stress characteristics are, from the material utilization ratio angle, in 1.8 2, disc spring storage elastic capacity is the largest, is a spring quality utilization rate and. Thus designed to ease impact, absorbing vibration need to store large amounts of elastic energy of disc spring selection

35、. For the automobile clutch diaphragm spring, design does not need to store a large amount of elastic energy, but according to the structure arrangement and separation needs to decide, general R/r value is 1.2 1.3. to R, diaphragm spring R diameter shall meet the requirements of structure and fricti

36、on plate diameter greater than the inner diameter of adaptation, friction plate, friction. Plate diameter. In addition, when the H, h and R/r constant, increased R in favor of diaphragm springStress dropDiaphragm spring starting cone angleAutomobile diaphragm spring conical bottom generally start at

37、 10 14 Diaphragm spring small end radius and radius of isolation bearingsThe value is mainly composed of structural decisions, minimum value should be greater than the first transmission shaft spline, separation effect is larger than the radius of the bearing.Separation index n, slot width, slot wid

38、th, and the window hole radiusAutomobile clutch diaphragm spring separation index n 12, generally at about 18, even when using, convenient manufacture mold dividing groove width of about 3mm, about 10mm, window hole radius r general case by( r-) = (0.8- 1.4)膜片弹簧的设计摘 要离合器是汽车传动系中的重要部件，主要功用是是切断和实现发动机对传

39、动系的动力传递，保证汽车平稳起步，保证传动系统换挡时工作平顺以及限制传动系统所承受的最大转矩，防止传动系统过载。膜片弹簧离合器是近年来在轿车和轻型汽车上广泛采用的一种离合器，它的转矩容量大而且较稳定，操作轻便，平衡性好，也能大量生产，对于它的研究已经变得越来越重要。关键字：离合器；膜片弹簧；膜片弹簧离合器概述膜片弹簧离合器是近年来在轿车和轻型载货汽车上广泛采用的一种离合器。因其作为压簧，可以同时兼起分离杠杆的作用，使离合器的结构大为简化，质量减少，并显著地缩短了离合器的轴向尺寸。其次，由于膜片弹簧与压盘以整个圆周接触，使压力分布均匀。另外由于膜片弹簧具有非线性弹性特性，故能在从动盘摩擦片磨损后

40、，弹簧仍能可靠的传递发动机的转矩，而不致产生滑离。离合器分离时，使离合器踏板操纵轻便，减轻驾驶员的劳动强度。此外，因膜片是一种对称零件，平衡性好，在高速下，其压紧力降低很少，而周布置弹离合器在高速时，因受离心力作用会产生横向挠曲，弹簧严重鼓出，从而降低了对压盘的压紧力，从而引起离合器传递转矩能力下降。那么可以看出，对于轻型车膜片弹簧离合器的设计研究对于改善汽车离合器各方面的性能具有十分重要的意义。作为压紧弹簧的所谓膜片弹簧，是由弹簧钢冲压成的，具有“无底碟子”形状的截锥形薄壁膜片，且自其小端在锥面上开有许多径向切槽，以形成弹性杠杆，而其余未切槽的大端截锥部分则起弹簧作用。膜片弹簧的两侧有支承圈

41、，而后者借助于固定在离合器盖上的一些（为径向切槽数目的一半）铆钉来安装定位。当离合器盖用螺栓固定到飞轮上时，由于离合器盖靠向飞轮，后支承圈则压膜片弹簧使其产生弹性变形，锥顶角变大，甚至膜片弹簧几乎变平。同时在膜片弹簧的大端对压盘产生压紧力使离合器处于结合状态。当离合器分离时，分离轴承前移膜片弹簧压前支承圈并以其作为支点发生反锥形的转变，使膜片弹簧大端后移，并通过分离钩拉动压盘后移使离合器分离。膜片弹簧离合器具有很多优点：首先，由于膜片弹簧具有非线性特性，因此设计摩擦片磨损后，弹簧压力几乎不变，且可以减轻分离离合器时的踏板力，使操纵轻便；其次，膜片弹簧的安装位置对离合器轴的中心线是对称的，因此其

42、压紧力实际上不受离心力的影响，性能稳定，平衡性也好；再者，膜片弹簧本身兼起压紧弹簧和分离杠杆的作用，使离合器结构大为简化，零件数目减少，质量减小并显著缩短了轴向尺寸；另外，由于膜片弹簧与压盘是以整个圆周接触，使压力分布均匀，摩擦片的接触良好，摩擦均匀，也易于实现良好的通风散热等。拉式膜片弹簧离合器的优点与推式相比，拉式膜片弹簧离合器具有许多优点：取消了中间支承各零件，并不用支承环或只用一个支承环，使其结构更简单、紧凑，零件数目更少，质量更少；拉式膜片弹簧是中部与压盘相压在同样压盘尺寸的条件下可采用直径较大的膜片弹簧，提高了压紧力与传递转矩的能力，且并不增大踏板力，在传递相同的转矩时，可采用尺寸

43、较小的结构；在接合或分离状态下，离合器盖的变形量小，刚度大，分离效率更高；拉式的杠杆比大于推式的杠杆比，且中间支承减少了摩擦损失，传动效率较高，踏板操纵更轻便，拉式的踏板力比推式的一般可减少约30%；无论在接合状态或分离状态，拉式结构的膜片弹簧大端与离合器盖支承始终保持接触，在支承环磨损后不会形成间隙而增大踏板自由行程，不会产生冲击和哭声；使用寿命更长。离合器膜片弹簧设计膜片弹簧的结构特点由前面可以知道，本设计中的压紧弹簧是膜片弹簧。而膜片弹簧离合器分推式和拉式，在本设计中采用拉式结构。 膜片弹簧在结构形状上分为两部分。在膜片弹簧的大端处为一完整的截锥体，它的形状像一个无底的碟子和一般机械上用

44、的碟形弹簧完全一样，故称作碟簧部分。膜片弹簧起弹性作用的正是其碟簧部分。碟形弹簧的弹性作用是这样：沿其轴线方向加载，碟簧受压变平，卸载后又恢复原形所。可以说膜片弹簧是碟形弹簧的一种特殊结构形式。所不同的是，在膜片弹簧上还包括有径向开槽部分。膜片弹簧上的径向开槽部分像一圈瓣片，它的作用是，当离合器分离时作为分离杠杆。故它又称分离爪。分离爪与碟簧部分交接处的径向槽较宽呈长方圆形孔。这样做，一方面可以减少分离爪根部应力集中，一方面又可用来安置销钉固定膜片弹簧，分离爪根部的过渡圆角R4.5。膜片弹簧的变形特性和加载方式由于膜片弹簧采用推式结构，故其正装。离合器在分离和接合时，膜片弹簧的加载情况不一样，

45、相应的有两种加载方式和变形情况：（1）接合时：离合器接合时，膜片弹簧起压紧弹簧之用，在压盘离合器盖总成未与飞轮装合以前，膜片弹簧近似处于自由状态，膜片弹簧对压盘无压紧作用。当压盘离合器盖总成与飞轮装合时，离合器盖前端面向飞轮前端面靠拢。因此，离合器盖通过支承环4对膜片弹簧施加载荷，膜片弹簧几乎变平。同时在压盘处也作用有载荷。我们把称作压紧力。支承环4和膜片弹簧压盘接触处之间的高度变化称作大端变形，膜片弹簧分离轴承相对于压盘高度的变化称之为小端变形。（2）分离时：当分离轴承以P2力作用在膜片弹簧的小端时，支承环4逐渐不起作用，而支承环5开始起作用。当P2力达到一定值时，膜片弹簧被压翻。分离时在膜

46、片弹簧的大端处及小端处将进一步产生附加变形和。此时膜片弹簧大端处的变形=+。膜片弹簧的弹性变形特性前面说过膜片弹簧起弹性作用的部分是其碟簧部分，碟簧部分的弹性变形特性和螺旋弹簧是不一样的，它是一中非线性的弹簧，其特性和碟簧部分的原始内截锥高H及弹簧片厚h的比值H/h有关。不同的H/h值可以得到不同的特性变形特性。一般可以分成下列四中情况：H/h 如下图7.1中H/h=0.5的曲线,其曲线形状表现为:载荷P的增加,变形总是不断增加.这种弹簧的刚度很大,可以承受很大的载荷,适合与作为缓冲装置中的行程限制器。H/h =如图7.1中H/h=1.5的曲线,弹性特性曲线在中间有一段很平直,变形的增加,载荷

47、P几乎不变.这种弹簧叫做零刚度弹簧.H/h2如图7.1中H/h=2.75者,弹簧的特性曲线中有一段负刚度区域,即当变形增加时,载荷反而减少具有这种特性的膜片弹簧很适合用于作为离合器的压紧弹簧,因为可利用其负刚度区,达到分离离合器时载荷下降,操纵省力的目的,当然负刚度过大也不适宜,以免弹簧工作位置略微变动造成弹簧压紧力过大.H/h如下图7.2,这种弹簧的的特性曲线中具有更大的负刚度不稳定工作区,而且有载荷为负值的区域.这种弹簧适合于汽车液力传动中的锁止机构。膜片弹簧的参数尺寸确定在设计膜片弹簧时，一般初步选定其全部尺寸然后进行一系列的验算，最后优选最合适的尺寸。其结构示意图见图H/h比值的选取 设计膜片弹簧时，要利用其非线性的弹性变形规律，因此要正确选择其特性曲线的形状，以获得最佳性能。一般汽车汽车膜片弹簧的H/h值的范围在