Clutch of new developments in technology
Abstract: in recent years car design and manufacturing technology progress for all to see. In order to further improve product performance, prolong service life, common mechanical clutch technology is also produced a remarkable change. No matter from structural characteristics, product process performance, or control technology, mechanical clutch of technological progress in some extent reflects the development of design concepts, and possible technology trends in the future.
Keywords: clutch; Technology development
1, introduction
In car technology rapid development today, especially with the electronic technology in cars, the extensive application of vehicle drivetrain is had great progress, as an important part of the transmission of the clutch assembly force transmission, the burden of reducing vibration and prevent system overload very important role. To make sure that the power transmission and reliable, separate thoroughly, combined with soft, damping good, small volume, light weight, easy, long service life, making the clutch product either cash from the performance, structure, or manufacturing mode and control, in the occurrence of a lot of change. They greatly optimized clutch all aspects of performance, to some extent look, these changes are also reflected the development direction of the clutch.
2, engine flywheel new structure
As one of the flywheel storage components engine, is also part of the clutch initiative. As the car transmission belong to multi-freedom torsional vibration system, whether the incentive and transmission system, or the associated force vibration type and the coupling vibration with other statements are very complex. In order to adapt to car driving conditions of vibration and noise reduction of reducing the need, making cars, ride comfort the role of torsional shock absorber is extremely important. It should be able to adjust the system inherent frequency, the system mainly low-order resonance critical speed remove common, also need to use speed range, still need to decrease amplitude damping of transmission system can reduce idle noise, ease the impact of the special case load. Previous clutch platen set on by a twist of shock absorber, decorate a space place is restricted, shock absorber work reverse Angle small, torsion stiffness big, capacity small, springs, and therefore not guarantee the intensity of vibration reduction is limited.
In recent years, the emergence of a reverse damping characteristics and performance to price are ideal double quality flywheel structure. The flywheel by primary flywheel, reverse shock absorber and subprime flywheel composition, among them, the primary flywheel on one hand we should provide for the shock absorber and clutch installation space, on the other hand also with appropriate rotational inertia insure a car, and reduce passed back starting the amplitude. Generally, double quality flywheel adopts with circular arc shape along the spiral spring primary flywheel outer periphery decorate way, in limited circumstances decorate a space, the arrangement to obtain larger primary flywheel rotational inertia. The inertia and the clutch after brief increase engine speed fluctuation of related parts, shorten their service life. To avoid the above phenomenon, often need additional Settings special damping, such, can increase the difficulty and cost of product development. Because the engine of the car front front drive type of transmission installation space is limited, so this kind of structure in FF type cars to the promotion. Meanwhile, this kind of decorate spring along the circumference, due to high speed double quality flywheel centrifugal role, spring wear when, or even produces broken.
Using radial layout springs can improve the double quality flywheel of the above mentioned products defect. It consists of primary flywheel, 3 ~ 4 springs box, damping dish and subprime flywheel composition. Because the suspension spring box of radial layout, the primary flywheel rely on four posts the muscles of rib takes form enough flywheel stiffness and produced similar with traditional flywheel inertia.
This kind is decorated in a small space to with smaller quality to gain the maximum rotation inertia, help reduce the assembly structure, the axial dimensions for subprime flywheel and clutch decorate a space make more. Its damping device by a wear-resisting plastic gasket, a belt of steel plate and a slot disc spring washers constitute, they set in damping plate, rely on damping disc hole flanging positioning and compaction, the damping disk with primary flywheel riveted by the subprime, plastic gasket flywheel slot drive. Practice proves that the double quality than ever, this structure can be the flywheel in a limited space get quite good vibration reduction.
Engine for the job, usually by the flywheel, inertia and the clutch clutch disc provides together. The ideal flywheel structure should be to offer the same, and ensure enough inertia structure stiffness premise to minimize the flywheel quality, stamping steel way to replace traditional casting can obtain the flywheel ways to produce the effect. Change the pressure by casting lron yuntechtc ring, start toothed ring and steel blunt system drivers disk of three parts. In the ring gear driving plate welding, pressure rings and drivers disk riveting, pressure ring of moment of inertia of the subject constitutes a flywheel, and provide for the clutch friction surface and heat conduction. Drivers disk improve enough flywheel stiffness, and using laser welding and clutch cover, this is connected to this structure forms of changes can be compared to traditional iron flywheel reduce quality 5% ~ 10%. USES the steel plate stamping type flywheel, and clutch cover and flywheel connections between after replacing bolt connection with welding, reducing the number and machinery manufactured parts, which reduces the production cost. The foregoing radial layout springs double quality can use this stamping yuntechtc for structure form, reducing axial dimensions
.
3, clutch disc
Clutch platen design of the main contradiction is facing, on one hand, hope to have as played platen diameter, in order to obtain the good preach torsional characteristic, reducing friction slices wear quantity and improve the service life, on the other hand, hope the decrease of the platen as possible, so as to shorten the rotational inertia of the variable transmission shift, ensure the synchronization time of smooth, transmission clutch platen ontology conscious drops, and therefore made wavy often difficult to coordinate the contradiction. When using triangle groove platen ontology structure, while keeping the original way wavy platen ontology has the axial elastic properties at the same time, because of its large on the plane can be formed, enough to make its and friction slices adhesive is used to connect the replacement of traditional riveting, so that in friction chip will not need the thickness of the steel back to reserve rivet, so clutch friction slices thickness, which can reduce the platen axial dimensions, and can be reduced by 10% of inertia can reduce nearly 25%. In other words, keep the premise of inertia unchanged, possible will platen diameter increases, so can the arrangement for torsional shock absorber, let a space when damper spring job increase, the rigidity of the shock absorber in diameter can be reduced greatly, increasing the space for setting also provides an ideal damping components fundamental conditions. On the other hand, because platen diameter increases, the optimization of diaphragm spring separation means it can obviously reduce leverage than the load bearing separation.
Using triangle groove platen ontology and friction piece of adhesive technology, still can make clutch friction slices surface pressure distribution, and more uniform can improve the service life of friction slices.
4, clutch diaphragm spring
Using the diaphragm spring of a nonlinear elastic properties, can increase the ability of clutch abrasion resistance. Usually, can pass the clutch when installation, adjustment diaphragm spring axial position, to keep the spring of compaction force, but due to the manufacturing process of previous position error is quite large, so often wasted spring this portion of elastic energy, enables the abrasion resistance ability get full play. When the clutch cover and flywheel connection with the above welding way to finish, the clutch assembly may allow such position when the adjustment, thus, the corresponding clutch scratch-resistant ability can improve the 4% ~ 30%.
To improve the ability to change its antiwear properties, but also can the diaphragm spring is reinforced by controlling method of separation means and the rib disc supporting ring approach to getting.
5, clutch control system
Automatic transmission in cars growing popularity of today, due to its lack of transmission efficiency of cars, and motorists feel lost control, makes mechanical clutch still has wide market. Along with the computer technology and the rapid development of modern control technology has to clutch may reality automatic control, automatic clutch management system (CMC) is the product of this idea. The driver speaking, clutch automatic control system is that it is the most obvious advantage of cancelled the clutch pedal, thus improve the driving comfort, whether in the city the frequent change of traffic environment, or in the ramp, its advantages are started is quite clear. Meanwhile, in order to reduce the transmission low noise and vibration, CMC is likely to clutch real-time control of sliding, all these can improve automobile driving safety. Although the automatic transmission can also play the same role in price, but the CMC, fuel efficiency, engine braking and rapid response, etc but again the obvious advantage. In addition, it has no peristalsis phenomenon, and can make control shift timing. Drivers On the other hand, for car itself, because the CMC reduced because the actual driving quite frequent false operation produces drivetrain stress, therefore, can reduce the transmission and its transmission parts design dimensions, in general driving conditions, electronic control ensures the accuracy and speed than artificially operation circumstance clutch of wear small, long service life.
CMC consists of three parts: namely is used to identify the driver intention and the clutch, the transmission working state of sensors,
Clutch actuators and electronic control unit, drivers shift HuanDangGan movements and intention through the release of the accelerator pedal to identify, this requires signal judge strategy and control must be very quick, to avoid the feeling of driver produce shift block, when pilots inadvertently tinkering with the transmission system when rod may not false action. In addition, the CMC through the engine speed, the transmission input shaft speed and throttle position signal to clutch slip for mind control, which can eliminate the car driving common vibration and noise. Such as a limit control to prevent slip in 1 and 2, block small throttle low-speed driving, the car slightly tilted forward, generating about 1Hz very uncomfortable zitterbewegung, through in the clutch of transient torsional direction change quickly, to eliminate the separation clutch in clutch under the condition of incomplete combinations, when pilots alternate relaxation and trample accelerator pedal, because the transmission torque change to the sharp produced recoiling sickening crash; or depressing Through the precise relative slip between 50 ~ 100rpm control, can eliminate in high-grade, high and low speed conditions when the engine driving torque values in the passenger cabin can smell the low-frequency resonance produced, and when the transmission in 2 ~ 3 block, engine speed 12 ~ 2500rpm and high load, the transmission possible beats noise; Through the separation clutch, convenient when the elimination of the idle will clutch and neutral transmission combine, engine torque peak in the transmission of idle speed noise produced. The key is to prevent vibration noise sensitivity and accuracy, this system requirements system has high control ability, rely on modern computer and hydraulic control technology has been possible this some.
6, closing
By adopting a new design concept, can make clutch axial dimensions is much shorter, platen diameter increases, power transmission more reliable, clutch capacity increases, separation bearing load is reduced, torsion vibration reduction improve, processing manufacturing easier, lower cost, service life can be extended 50% and than before can be expected, along with the automatic control technology mature gradually perfect, clutch control mode will also continue to rapid development.
汽车离合器技术的新发展
摘要：近年来汽车设计和制造技术的进步有目共睹。为了进一步提高产品性能，延长使用寿命，普通机械式离合器技术同样也产生了令人注目的变化。无论从结构特性、产品工艺性能，还是控制技术方面，机械离合器的技术进步从某种程度上反映了设计观念的发展，以及将来可能的技术走势。
关键词：离合器；技术发展
1、引言
在汽车技术飞速发展的今天，特别是伴随着电子技术在汽车上的广泛应用，汽车传动系有了长足的进步，作为传动系重要组成部分之一的离合器总成负担着传力、减振和防止系统过载等十分重要的作用。为确保其传力可靠，分离彻底，结合柔顺，减振好，体积小，重量轻，寿命长，制造易，现金的离合器产品无论从性能、结构方面，还是生产制造方式和操纵控制方面，都在发生着诸多的变化。它们大大地优化了离合器各方面的性能，从某种程度上看，这些变化也反映了汽车离合器的发展方向。
2、发动机飞轮的新结构
作为发动机储能元件之一的飞轮，同时也是离合器的主动部分。由于汽车传动系属于多自由度扭转振动系统，无论是系统的激励和传递的力，还是随之产生的振型和与其它振动的耦合情况均十分复杂。为了能适应汽车各种行驶工况下减少振动、降低噪声的需要，提高汽车的乘坐舒适性，扭转减震器的作用极其重要。它应能够通过调节系统固有频率，将系统主要的低阶共振临界转速移出常用车速范围，也需要利用阻尼减小振幅，还需能降低传动系统的怠速噪声，缓和特殊工况下的冲击载荷。以往在离合器从动盘上设置的扭转减震器，由于受布置空间所限，减震器工作扭转角度小，扭转刚度大，容量小，减振弹簧强度不易保证，因此减振效果有限。
近年来，出现了扭转减振特性和性能价格比均较理想的双质量飞轮结构。这种飞轮由初级飞轮、扭转减振器和次级飞轮组成，其中，初级飞轮一方面要为减震器和离合器提供安装空间，另一方面也以适当的转动惯量确保汽车起动，并减少向后传递的振幅。通常，双质量飞轮均采用以圆弧状螺旋弹簧沿初级飞轮外圆周布置的方式，在布置空间有限的情况下，这种布置方式难以获得较大的初级飞轮转动惯量。该转动惯量过小会增加发动机和离合器相关零件的速度波动，缩短他们的使用寿命。为避免上述现象发生，常需附加设置特殊的阻尼，这样，会增加开发难度和产品成本。由于发动机前置前驱动型式的轿车的变速器安装空间有限，故这种结构难以在FF式轿车上推广。同时，这种沿圆周布置弹簧的双质量飞轮，由于高速时离心力作用，弹簧磨损大，甚至会产生折断。
采用径向布置减振弹簧的双质量飞轮可改进上述产品的缺陷。它由初级飞轮、3~4个减振弹簧盒、阻尼盘和次级飞轮组成。由于这种减震弹簧盒径向布置，在初级飞轮上依靠四根宽厚的筋肋形成足够的飞轮刚度，并产生与传统飞轮相近的转动惯量。
这种布置有利于在小空间上，以较小的质量获得最大的转动惯量，有利于减少总成结构的轴向尺寸，为次级飞轮和离合器让出更多布置空间。其阻尼装置由一个耐磨塑料垫圈、一个带槽口的钢片和一个碟形弹簧垫圈构成，它们设置在阻尼盘上，靠阻尼盘内孔翻边定位并压紧，阻尼盘与初级飞轮铆接，塑料垫圈由次级飞轮上的槽口带动。实践证明，较之以往的双质量飞轮，这种结构可在有限的空间内获得相当好的减振效果。
发动机工作所需的转动惯量通常由飞轮、离合器压盘和离合器一起提供。理想的飞轮结构应在提供相同转动惯量，并保证足够结构刚度的前提下尽量减少飞轮质量，以钢板冲压方式取代传统铸造方式生产的飞轮可获得这种效果。改飞轮由铸铁制的压环、起动齿环和钢板冲制的驱动盘三部分组成。齿环焊接在驱动盘上，压环与驱动盘铆接，压环构成飞轮转动惯量的主体，同时为离合器提供摩擦面和传导热量。驱动盘提高足够的飞轮刚度，并借助激光焊接与离合器盖相连接，这这种结构形式的改变可较传统铸铁飞轮减少质量5%~10%。采用钢板冲压式飞轮，且离合器盖与飞轮间的连接以焊接取代螺栓连接后，减少了零件数和机械加工量，从而降低了生产费用。前述的径向布置弹簧双质量飞轮亦可采用这种冲压方式构成，以利于结构减小轴向尺寸。
3、离合器从动盘
离合器从动盘设计中面临的主要矛盾是，一方面希望有尽可能打得从动盘直径，以便获得好的传扭特性、减少摩擦片磨损量和提高使用寿命，另一方面又希望尽可能的减小从动盘的转动惯量，以缩短变速同步时间，保证变速器换挡的平顺，传动离合器从动盘本体有意识滴制成波浪状，因此往往难以协调这种矛盾。当采用三角形槽式从动盘本体结构时，它在保留原方式波浪状从动盘本体所具有的轴向弹性特性的同时，由于其上可形成大面积的平面，足以使其与摩擦片连接采用粘接替代传统的铆接，这样，在摩擦片上便无需预留铆钉钢背的厚度，故离合器摩擦片厚度可减小，由此从动盘的轴向尺寸可减小10%，而转动惯量可降低近25%。换句话说，在保持转动惯量不变的前提下，有可能将从动盘直径增大，这样可为扭转减振器的布置让出空间，当减震器弹簧工作直径增大时，减振器刚度可大大降低，空间的增大也为设置理想的阻尼元件提供了基本条件。另一方面，由于从动盘直径增大，使得优化膜片弹簧分离指的杠杆比可以明显地减少分离轴承上的负荷。
利用三角形槽式从动盘本体和摩擦片的粘接技术，还能使离合器摩擦片表面的压力分布更均匀，因而能提高摩擦片的使用寿命。
4、离合器的膜片弹簧
利用膜片弹簧的非线性弹性特性，可以增加离合器抗磨损的能力。通常，可以通过离合器安装时调节膜片弹簧轴向位置，来保持弹簧的压紧力，但以往由于制造过程中这种位置误差相当大，故往往会浪费掉弹簧的这部分弹性势能，使得这种抗磨损能力得不到充分发挥。当离合器盖与飞轮的连接采用上述焊接的方式完成，离合器装配时便可能容许这种位置的调整，由此，相应的离合器抗磨损能力可提高4%~30%。
为提高离合器的抗磨损能力而改变膜片弹簧特性，还可以通过控制分离指筋肋的方法和采用碟形支承环的方式获得。
5、离合器控制系统
在汽车自动变速器日益普及的今天，由于其传动效率的不足，以及驾车人对汽车失去控制权的感觉，使得机械式离合器至今仍有着广泛的市场。随着计算机技术和现代控制技术的迅速发展，已有可能现实对离合器的自动控制，自动离合器管理系统（CMC）便是这种思想的产物。对驾驶员来说，离合器自动控制系统最明显的优点在于它取消了离合器踏板，从而提高了驾驶舒适性，无论在城市频繁变化的交通环境中，还是在坡道起步时，其优越性都是十分明显的。于此同时，为了减少传动系低速噪声和振动，CMC有可能对离合器滑动进行实时控制，所有这些都可以改善汽车的行驶安全性。尽管自动变速器也能起到相同的作用，但CMC在价格、燃油经济性、发动机制动和快速响应等方面却又着明显的优势。此外，它无蠕动现象，且可使驾驶员自己控制换挡时机。另一方面，对汽车本身来说，由于CMC减少了因实际行驶中相当频繁的误操作产生的传动系应力，因此，可减小变速器及其传动系零件的设计尺寸，在一般驾驶条件下，电子控制的精度和速度保证了离合器比人工操作情况下的磨损小，使用寿命长。
CMC由三部分组成：即用来识别驾驶员意图和离合器、变速器工作状态的传感器，
离合器执行器和电子控制单元，驾驶员换挡意图通过换挡杆动作和油门踏板的释放信号来识别，这要求判断策略和控制必须十分快捷，以避免驾驶员产生换挡阻滞的感觉，当驾驶员无意中摆弄变速器杆时系统不得误动作。另外，CMC通过发动机转速、变速器输入轴转速和节气门位置信号对离合器滑转进行精神控制，可消除汽车行驶中常见的振动与噪声。如以有限度控制滑转来防止在1、2挡小油门低速行驶时，汽车轻微朝前倾斜，产生约1Hz非常不舒服的颤振，通过在离合器扭转方向改变的瞬时迅速分离离合器，来消除在离合器完全结合的情况下，当驾驶员交替放松和踩踏油门踏板时，因传动系扭矩变向的反冲作用产生的尖锐或沉闷的撞击声；通过精确地将相对滑转控制在50~100rpm之间，可消除在高档、大功率和低转速工况下行驶时发动机扭矩值在乘客舱内产生的可闻低频共振，以及当变速器处于2~3挡，发动机转速1200~2500rpm且高负荷时，变速器可能产生的拍击噪声；通过分离离合器，可方便的消除怠速时将离合器与空挡变速器结合时，发动机扭矩峰值在变速器中产生的怠速噪声。预防振噪声的关键是系统灵敏度和精度，这要求系统具有高的控制能力，依靠现代计算机和液压控制技术已有可能做到这一些。
6、结束语
采用新的设计理念，可使离合器轴向尺寸大为缩短，从动盘直径增大，传力更可靠，离合器容量增大，分离轴承负荷降低，扭转减振效果改善，加工制造更容易，成本降低，使用寿命可较以前延长50%，同时可以预料，伴随着自动控制技术的日臻成熟完善，离合器的控制方式也将继续快速的发展。
