1、广东技术师范学院天河学院本科毕业设计外文翻译译文学生姓名 陈剑锋 院（系） 广东技术师范学院天河学院 专业班级 机械设计制造及其自动化 指导教师 蒋文明 完成日期 2011.12.30 外文出处：http:/en.wikipedia.org/wiki/Leaf_springLeaf spring historyThere were a variety of leaf springs, usually employing the word “elliptical“. “Elliptical“ or “full elliptical“ leaf springs referred to two ci
2、rcular arcs linked at their tips. This was joined to the frame at the top center of the upper arc, the bottom center was joined to the “live“ suspension components, such as a solid front axle. Additional suspension components, such as trailing arms, would be needed for this design, but not for “semi
3、-elliptical“ leaf springs as used in the Hotchkiss drive. That employed the lower arc, hence its name. “Quarter-elliptic“ springs often had the thickest part of thestack of leaves stuck into the rear end of the side pieces of a short ladder frame, with the free end attached to the differential, as i
4、n the Austin Seven of the 1920s. As an example of non-elliptic leaf springs, the Ford Model T had multiple leaf springs over its differential that were curved in the shape of a yoke. As a substitute for dampers(shock absorbers), some manufacturers laid non-metallic sheets in between the metal leaves
5、,such as wood.Leaf springs were very common on automobiles, right up to the 1970s in Europe and Japan and late 70s in America when the move to front-wheel drive, and more sophisticated suspension designs saw automobile manufacturers use coil springs instead. Today leaf springs are still used in heav
6、y commercial vehicles such as vans and trucks, SUVs, and railway carriages. For heavy vehicles, they have the advantage of spreading the load more widely over the vehicles chassis, whereas coil springs transfer it to a single point. Unlike coil springs, leaf springs also locate the rear axle, elimin
7、ating the need for trailing arms and a Panhard rod, thereby saving cost and weight in a simple live axle rear suspension.A more modern implementation is the parabolic leaf spring. This design is characterised by fewer leaves whose thickness varies from centre to ends following a parabolic curve. In
8、this design, inter-leaf friction is unwanted, and therefore there is only contact between the springs at the ends and at the centre where the axle is connected. Spacers prevent contact at other points. Aside from a weight saving, the main advantage of parabolic springs is their greater flexibility,
9、which translates into vehicle ride quality that approaches that of coil springs. There is a trade-off in the form of reduced load carrying capability, however. The characteristic of parabolic springs is better riding comfort and not as “stiff“ as conventional “multi-leaf springs“. It is widely used
10、on buses for better comfort. A further development by the British GKN company and by Chevrolet with the Corvette amongst others, is the move to composite plastic leaf springs.Typically when used in automobile suspension the leaf both supports an axle and locates/ partially locates the axle. This can
11、 lead to handling issues (such as axle tramp), as the flexible nature of the spring makes precise control of the unsprung mass of the axle difficult. Some suspension designs which use leaf springs do not use the leaf to locate the axle and do not have this drawback. The Fiat 128s rear suspension is
12、an example.Figure 1 leaf spring a variety of shapesLeaf spring manufacturing processMulti-leaf springs are made as fllows:1.Shearing of flat bar2.Center hole punching/Drilling3.End Heating process forming (hot & cold process) 1.Eye Forming/Wrapper Forming2.Diamond cutting/end trimming/width cutting/
13、end tapering3.End punching/end grooving/end bending/end forging/eye grinding4.Center hole punching/Drilling/nibbing4.Heat Treatment 1.Heating2.Camber forming3.Quenching4.Tempering5.Surface preparation 1.Shot peening/stress peening2.Painting6.Eye bush preparation process 1.Eye reaming/eye boring2.Bus
14、h insertion3.Bush reaming7.Assemble 1.Presetting & load testing2.Paint touch-up3.Marking & packing外文中文翻译：板簧历史板簧的种类各种各样，经常用的“椭圆”“全椭圆”板簧指两个端点相连的形。上面的拱形的上方中心与框架连接，下方中心与“主动”悬挂部件相连，例如固体前轴。其他的悬架部分，例如纵向推力杆，也在这样的设计中用到，但是不用在霍奇凯斯传动的“半椭圆”板簧。 这样的板簧使用更低的拱形，因此它的名字叫做“四分之一椭圆”簧片，这样的簧片经常使用短梯式框架的侧片后部堆积的金属片的最厚的部分，悬空或者连
15、接在差速器上，就像19世纪20年代的奥斯汀史蒂芬。对于“非椭圆”板簧，福特T型车的弯成牛轭形状的差速器上有多重板簧，作为阻尼器（震动吸收器）的替代，一些生产商把非金属的薄板放在金属片中间，例如木头。板簧在机动车中使用很多，在欧洲和日本的19世纪70年代和美国的70年代后期，当机动车发展为前轮驱动和更加复杂的悬架设计时，更多机动车生产商使用卷簧。今天，板簧仍然在重型贸易机动车中，例如运货车和卡车，越野车和轨道车厢。对于重型机动车来说，这些板簧能够把车的载重广泛的分散到车的地盘上，然而卷簧只能把载重转化到一个点上。不像螺旋弹簧，板簧能够固定后轴，这样就不需要纵向推力杆和横向推力杆了，因此通过简单的
16、主动轴后悬挂装置节省了成本和重量。更现代的是抛物线式的板簧。这样的设计具有更少的金属薄片，从中间部分到两端的薄片厚度不同，形成一个抛物线式的曲线。在这样的设计中，金属片之间的摩擦是不利的，因此只有弹簧的两端和与主轴相连的中部相互接触。之间的空间也防止了其他点的接触。除了节省重量，抛物线式的板簧的主要优点还在于更强的灵活性，能够使机动车达到像使用螺旋弹簧而达到的乘坐舒适性，然而，这之中存在一种载重承受力减少的权衡效应。抛物线式的板簧能够带来更好的乘坐舒适性，不像传统的“多金属片板簧”那样僵硬。抛物线式板簧被广泛的使用在公共汽车中以提高乘坐舒适度。由英国吉凯恩公司和雪佛兰与克尔维特开发的新型板簧是
17、复合材料板簧。当用于机动车悬架时，板簧既支撑主轴，又固定或部分固定主轴。这会带来一些问题（例如主轴拖地），因为弹簧的弹性无法对主轴无弹性的地方进行精确的控制。一些使用板簧的悬架设计不用金属片固定主轴，因此不会出现这样的缺陷，像菲亚特128的后悬架设计。 图1 板簧各种形状板簧制造工艺多片板簧如下：1、扁钢条削剪2、中心打眼/钻孔3、加热端部加工（冷/热加工）(1)眼制造/包装制造(2)金刚石切割/端部修剪/宽度切割/端部磨细(3)打眼/端部开槽/端部弯曲/端部锻造/磨眼(4)中心打眼/钻孔/捏4、加热处理(1)加热(2)形成弧形(3)挤压(4)降温5、表面准备(1)喷丸加工/ 喷丸强化(2)喷漆6、钻眼的衬套准备工序(1)挖眼/钻孔(2)插入衬套(3)挖衬套7、组装(1)预调整和承载测试(2)喷漆润色(3)标记/包装翻译工具有：牛津高阶英汉双解词典（第六版）牛津大学出版社机械工程专业英语（第十版）哈尔滨工业大学出版社谷歌翻译
