商品轿车运输车改装设计(11)

黑龙江工程学院本科生毕业设计

致 谢

此次毕业设计是对我大学四年所学知识的一次全面考验，也是对即将走向社会的我们的进行的一次有效的锻炼。回顾这场毕业设计，我觉得受益菲浅：它让我体会到做研究不仅要具有细心、专心和耐心的精神，更多的是要有一颗平静的心来面对一系列可能遇到的困难。

本文是在王革新老师悉心指导下完成。从课题的选取、进一步的理论研究，到论文的撰写都得到了王革新老师的指导与热情帮助。在他严谨的治学态度和一丝不苟的工作作风下，我获益非浅，使我对自己的工作及课题研究有了更深的认识，在此表示衷心的感谢。

感谢所有帮助我的老师、同学和关心我的朋友们！感谢一直以来默默支持我的老师和同学们，是他们辛勤的汗水换来我今天的这一切，在此表示衷心的

感谢。

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黑龙江工程学院本科生毕业设计

附 录(A) 英文文献 Semi-trailer truck

A semi-trailer truck, also known as a semi, tractor-trailer, or (in the United Kingdom and Ireland) articulated truck or articulated lorry, often abbreviated to artic, is an articulated vehicle consisting of a towing engine (tractor in the United States, prime mover in Australia, lorry in Ireland and truck in the UK, Canada and New Zealand), and a semi-trailer (plus possible additional trailers) that carries the freight. A semi-trailer does not trail completely behind the towing vehicle, but is attached at a point that is forward of the rear-most axle of the towing unit, so that some fraction of the weight of the trailer is carried by the rear axle(s) of the prime mover. This arrangement requires both tractor and semi-trailer to be distinct in design from a rigid truck and trailer.

In North America, semi tractors usually have 3 axles, the front, or \having two wheels, and each of the two rear, \(double wheels) on each side. Thus, the most common configuration of tractor has 10 wheels, however in some cases dual wheels are replaced by tires known as \singles\weight reduction is about 180 lbs per axle when using super singles). In this case the tractor will only have six wheels. A smaller tractor, having a single drive axle (six wheeler) is often used to pull shorter trailers in tight urban environments, such as downtown areas where a 60-foot rig would be too difficult to maneuver. Day cabs (trucks without sleeper units) usually don't have single axles, but both day cabs and trucks with sleepers are produced with them.

The cargo trailer usually has two \wheels, or eight wheels on the trailer. Many trailers are equipped with movable

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黑龙江工程学院本科生毕业设计

tandems and fifth wheels that can be set to adjust the weight on each axle to stay within legal limits.

Although the sum of the weights of the tractor and the trailer (the gross weight) is normally limited to a certain amount, some roads are marked with a different gross restriction to prevent road damage. Cargoes that exceed allowed weights are usually marked with overweight load and must obtain a permit to use certain roads. Rules governing the maximum size and weight of vehicles differ from one U.S. state to another. However, since the majority of hauling is done on the interstate system, the vast majority of trucks and trailers made in the U.S. are built to the specifications of the Department of Transportation (DOT), which governs the use of the interstate system. The DOT has established these vehicle limits: 102 inches wide, 13.5 feet in height, and 80,000 lbs gross weight. These limits can be exceeded as individual states have the right to issue temporary oversize and/or overweight permits. Trailer dimensions vary greatly, depending on the amount and type of cargo it was designed to haul. (See types of trailers under Construction, below.)

Although dual wheels are most common, use of two single, wider tires(known as \carriers and other weight-sensitive operators. With a growing desire to reduce greenhouse gas emissions the use of the super single tire is gaining popularity. The three advantages of this configuration are : (1) super singles reduce fuel consumption. Testing on an oval track (Canada 2009) showed 10% fuel savings when using super singles. The savings come from less energy wasted flexing tire side walls. Fewer tire side walls equates to less wasted energy; (2) the lighter tire weight allows a truck to be loaded with more freight; (3) the single wheel covers less of the brake unit, which allows faster cooling and reduces brake fade.

Perhaps the largest disadvantage is when one tire becomes deflated or destroyed, the remaining tire (in a dual axle configuration) may not prevent the load from causing damage to rim of the deflated tire before the vehicle is stopped. In a dual tire configuration the rim of the deflated tire is prevented from touching the roadway by

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黑龙江工程学院本科生毕业设计

the fully inflated tire mounted beside it. (Note: it is illegal to drive a commercial vehicle with a deflated or destroyed tire).

Another innovation rapidly growing in popularity is the skirted trailer. The area between the road and the bottom of the trailer frame was previously left open, however the air moving under the trailer is a source of aerodynamic drag. Also without the trailer skirt drivers of smaller cars may attempt to drive under the trailer, resulting in accidents. Oval track testing (Canada 2009) proved it is possible to improve fuel economy by 8%, depending on the design and installation

configuration of the trailer skirt. The more completely the airflow under the trailer is blocked the better the improvement in fuel economy.

The United States also allows 2-axle tractors to tow two 1-axle 28.5-foot (8.7 m) semi-trailers known officially as STAA doubles and colloquially as doubles, a set, or a set of joints on all highways that are part of the National Network. The second trailer in a set of doubles uses a converter gear, also known as a con-gear or dolly. This apparatus …… 此处隐藏：3931字，全部文档内容请下载后查看。喜欢就下载吧 ……