多楔带现状与最新技术发展

现代汽车发动机前端附件传动轮系日趋复杂。轮系设计直接影响整车的工作可靠性，因此受到世界各大汽车公司的高度重视。传统的发动机附件传动轮系一直采用V带传动，但由于其弯曲性能较差，已无法满足现代汽车在较小空间内传动多个附件的要求。多楔带集平带的高柔韧性和V带的高功 率性于一体，不仅可用一条带传动多个附件，而且能双面使用，例如采用背部张紧装置，使许多原来用V带传动的设计困难迎刃而解。多楔带的应用为发动机前端附 件传动轮系设计开辟了新的途径。目前欧美国家发动机前端附件传动轮系已基本全部采用多楔带；日本基于可靠性考虑，多采用一条多楔带与V带并用形式。

    但是，由于现代汽车发动机空间越来越小，带传的部件多和功率大，而使用多楔带多为单根带传多个部件，因此对多楔带的性能要求非常的高，一般要求能在 120℃高温下使用寿命大于100 000km。传统的CR材料已无法达到要求，目前多用HNBR。图3为HNBR多楔带与不同CR多楔带在110℃和130℃下的疲劳寿命对比1[3]，可以看出HNBR多楔带的疲劳寿命比CR多楔带高得多，尤其是在高温条件下。

 

汽车多楔带是汽车发动机重要的零部件，也是传动带重要的组成部分。可以说，传动带的许多技术进步和发明与汽车工业的发展息息相关，如V带发明，切边V带、多楔带和同步带的快速发展，氢化丁腈橡胶（HNBR）在同步带应用、三元乙丙橡胶（EPDM）在多楔带应用等，都是为了适应汽车工业最新技术要求而获得迅速发展的。汽车多楔带发展趋势主要往高性能、长寿命、节能、高精度、低排放和低噪音及集成化模块式等方向发展。

 

近年来，由于全球气候变暖、环境保护和对汽车舒适性要求，节能、排放和NVH（噪音、振动和平稳）是汽车工业主要话题。如何提高燃料利用率和减少废气排放、提高维修周期一直是汽车工业研究目标，这些技术包括多阀门（Multivalve Engines，MVES）和变阀门（Variable Valve Timing ，VVT）技术[1]、催化转换器、42V发电/启动集成电机（integrated starter alternator，ISA）[2]、直喷式柴油发动机和240 000 Km甚至300 000 Km维修周期[3]等。这些技术进步对汽车零部件的性能要求也相应提高和苛刻，汽车传动带也不例外。为了适应这些变化，国外一些著名传动带厂家对汽车多楔带进行了许多改进和性能提高。

1．弹性多楔带

弹性多楔带最早用于白色家电如洗衣机、干洗机和健身器材等。原理是，带的长度比轮系计算周长小，带在装配时，使用专用工具强制拉伸在固定的带轮上，通过带的弹性变形力使带产生足够的张力。在整个使用过程中无需调整张力，这样可以省略张力调节机构。近几年来，小型家用轿车为了简化发动机前端附件传动轮系结构也开始使用弹性多楔带作为驱动用带。弹性多楔带一般使用扯断伸长率大于20%的高捻度的尼龙纤维作为强力层线绳。

 

2．齿形多楔带

齿形多楔带类似于齿形切边V带，即在楔部切成齿形，以提高带的曲挠性能及带散热性能，可明显提高带使用寿命。固特异公司研究表明，相同的氯丁橡胶（CR）材料多楔带，高温疲劳试验普通多楔带66h，有齿多楔带可达167h[5]。有齿多楔带还可降低对带的装配精度要求。但有齿多楔带在使用时通过带轮会带进带出空气流，产生有节奏的气流声。固特异公司通过斜齿，DAYCO公司做成不规则齿来抵消这种声音，可减少15dB左右的噪音。两家公司分别以 “Gatorhark”和“POLY COG”标识推向市场。

 

3．EPDM多楔带

近年来，多楔带在汽车得到普遍应用，而发动机室的温度越来越高，有的要求橡胶件能耐150℃，瞬间能耐170℃，传统氯丁橡胶（CR）显然达不到要求。由于HNBR过于昂贵，人们在研究发现小量的油污并不对发动机前端的皮带造成损害[9]，可使用较廉价耐热性好多的三元乙丙橡胶（EPDM）作为多楔带主体橡胶材料。但EPDM耐磨性、高温抗撕裂和动态性能不理想，与其它材料粘合差，这些都需要通过改性如添加ZDA或ZDMA和与其它材料并用加以解决。

EPDM多楔带耐高温性能和高温疲劳寿命明显提高，如CR多楔带107℃下疲劳寿命只有50h，而EPDM多楔带在121℃下疲劳寿命可达125h[5]。CONTITECH开发的EPDM多楔带使用寿命已达240 000Km，

 

4．植绒多楔带

多楔带传动缺点之一是传动噪音较大，在低速或角速度变化快使用时，以及一段时间后，楔面磨损、硬化和张力松弛，或在雨天沾到水后，传动时会发出刺耳的尖叫声，影响汽车的NVH性能。解决办法之一是楔面留有0.1～1.0mm高强度短纤维（如芳纶、PBO纤维等）由于纤维摩擦系数稳定、具有吸音功能，因此大大降低多楔带传动噪音，植绒多楔带一般用特殊的研磨工艺来实现。研磨时，先将楔快速磨成大致的楔形，然后低速湿磨，将橡胶磨掉，楔面露出一定长度的纤维。Ribbed status quo with the latest technological developments


The increasing complexity of modern automotive engine front-end accessory drive wheel. The gear train design a direct impact on vehicle reliability, and therefore attach great importance to the world's major car companies. The conventional engine accessory drive gear train has been using the V-belt transmission, but because of its poor bending properties, has been unable to meet the requirements of the modern cars in less space drive multiple attachments. Ribbed set the high flexibility of flat belts and V-band high-power, not only can be used a belt drive multiple attachments, and using both sides, for example, using the back of the tensioning device, so that many of the original with V-belt transmission design difficulties solved. The Ribbed application engine front-end accessory drive wheel is designed to open up a new way. Europe and the United States the engine front end accessory drive gear train has been basically used in all V-ribbed belts; Japan based on reliability considerations, the use of a V-ribbed belts and V-belts and use forms.

    However, due to the modern automobile engine space is getting smaller and smaller, with the transfer of parts and power of large, use Ribbed single band pass multiple components require very high and therefore the performance of the V-ribbed belts, the general requirements In the high temperature of 120 ℃ life of more than 100 000km. Traditional CR material has been unable to meet the requirements of the current multi-use of HNBR. 110 ° C and 130 ° C, the fatigue life for the HNBR Ribbed different CR Ribbed contrast to a [3], we can see the the HNBR Ribbed fatigue life is much higher than the CR Ribbed, especially In the high temperature conditions.

 

Automotive Ribbed important parts of an automobile engine, belt an important part of. It can be said that the belt of technological progress and invention of the automobile industry is closely related to the development, such as the V-belt invention, cutting edge V-belt, the rapid development of the V-ribbed belts and timing belts, hydrogenated nitrile rubber (HNBR) in the timing belt, three yuan ethylene propylene rubber (EPDM) Ribbed applications are in order to adapt the requirements of the automotive industry the latest technology and rapid development. Automotive Ribbed development trends to develop in the direction of high-performance, long life, energy saving, high-precision, low emissions and low noise and the integrated module type.

 

In recent years, due to global warming, environmental protection and the car's comfort requirements, energy efficiency, emissions and NVH (noise, vibration and smooth) is the automotive industry the main topic. How to improve fuel efficiency and reduce emissions, improve the maintenance cycle has been in the automotive industry research objectives, these technologies include multi-valve (Multivalve of Engines, MVES) and variable valve (Variable Valve Timing VVT) technology [1], catalytic converter , 42V power generation / boot integrated motor (integrated starter alternator, ISA) [2], direct injection diesel engine and 240 000 in the Km and even 300 000 the Km maintenance cycle [3]. These technical advances auto parts performance requirements have been increased and harsh, automotive belt is no exception. In order to adapt to these changes, some foreign famous belt manufacturers vehicle Ribbed many improvements and performance improvements.

A. Flexibility Ribbed

Elastic Ribbed earliest for white goods such as washing machines, dry cleaning machines and fitness equipment and so on. The principle is that, with the length of the gear system to calculate the circumference of a small belt assembly, using a dedicated tool to force the stretch in the fixed pulley deformation by the elastic band force with enough tension. No need to adjust the tension in the entire process, so you can omit the tension adjusting mechanism. In recent years, a small family car in order to simplify the structure of the engine front end accessory drive gear train flexibility Ribbed as a driver to use with. Elastic Ribbed general tensile elongation greater than 20% high-twist nylon fiber layer as a strong cord.

 

Two. Tooth Ribbed

Tooth the Ribbed similar to the tooth edged V belt, namely the Ministry of the wedge cut into the tooth, in order to improve the flex band and with heat dissipation, and can significantly increase the belt life. Goodyear study shows that the same material chloroprene rubber (CR), ribbed belt, high temperature fatigue test common Ribbed 66h, V-ribbed belts have teeth up to 167h [5]. Toothed V-ribbed belts can reduce the belt assembly precision requirements. However, tooth V-ribbed belts in use through the pulley into the belt out of the air stream, resulting in the rhythmic sound of the airflow. Goodyear through the helical gear, DAYCO company made up of irregular teeth to offset the sound can be reduced about 15dB of noise. The two companies were "Gatorhark" and "POLY the COG logo to market.

 

3. EPDM ribbed belts

In recent years, ribbed belts widely used in the automotive and engine room temperature is getting higher and higher, and some require the rubber pieces capability of 150 ° C, the instant capability of 170 ° C, apparently fail to meet requirements of the traditional chloroprene rubber (CR). HNBR is too expensive, the study found that a small amount of oil does not cause damage to the engine front-end of the belt [9], you can use cheaper heat resistance, a lot of ethylene propylene diene monomer rubber (EPDM) as a V-ribbed belts the main rubber material. EPDM wear resistance, high temperature and tear and dynamic performance is not satisfactory, and poor adhesion with other materials, which are by modification such as adding ZDA or ZDMA, and other materials and to solve them.