外文翻译--动力转向系统

附录 B History The earliest known patent related to power steering was that by Frederick W. Lanchester in the UK,in February 1902. His invention was to cause the steering mechanism to be actuated by hydraulic power. The next design was filed as recorded by the US Patent Office on August 30, 1932, by Klara Gailis, from Belmont, Massachusetts. There is another inventor credited with the invention of power steering by the name of Charles F. Hammond an American, born in Detroit, who filed similar patents, the first of which was filed as recorded by the Canadian Intellectual Property Office. Chrysler Corporation introduced the first commercially available power steering system on the 1951 Chrysler Imperial under the name Hydraguide. Most new vehicles now have power steering, owing to the trends toward front wheel drive, greater vehicle mass, and wider tires, which all increase the required steering effort. Heavier vehicles as common in some countries would be extremely difficult to maneuver at low speeds, while vehicles of lighter weight may not need power assisted steering at all Hydraulic systems A power steering fluid reservoir and pulley driven pump Most power steering systems work by using a hydraulic system to turn the vehicles wheels. The hydraulic pressure is usually provided by a gerotor or rotary vane pump driven by the vehicles engine. A double-acting hydraulic cylinder applies a force to the steering gear, which in turn applies a torque to the steering axis of the roadwheels. The flow to the cylinder is controlled by valves operated by the steering wheel； the more torque the driver applies to the steering wheel and the shaft it is attached to, the more fluid the valves allow through to the cylinder, and so the more force is applied to steer the wheels in the appropriate direction. One design for measuring the torque applied to the steering wheel is to fix a torsion bar to the end of the steering shaft. As the steering wheel rotates, so does the attached steering shaft, and so does the top end of the attached torsion bar. Since the torsion bar is relatively thin and flexible and the bottom end is not completely free to rotate, the bar will soak up some of the torque； the bottom end will not rotate as far as the top end. The difference in rotation between the top and bottom ends of the torsion bar can be used to control the valve that allows fluid to flow to the cylinder which provides steering assistance； the greater the twist of the torsion bar, the more steering assistance will be provided. Since the pumps employed are of the positive displacement type, the flow rate they deliver is directly proportional to the speed of the engine. This means that at high engine speeds the steering would naturally operate faster than at low engine speeds. Because this would be undesirable, a restricting orifice and flow control valve are used to direct some of the pumps output back to the hydraulic reservoir at high engine speeds. A pressure relief valve is also used to prevent a dangerous build-up of pressure when the hydraulic cylinders piston reaches the end of the cylinder. Some modern implementations also include an electronic pressure relief valve which can reduce the hydraulic pressure in the power steering lines as the vehicles speed increases (this is known as variable assist power steering). DIRAVI In the DIRAVI system invented by Citron, the force turning the wheels comes from the cars high pressure hydraulic system and is always the same no matter what the road speed is. As the steering wheel is turned, the wheels are turned simultaneously to a corresponding angle by a hydraulic piston. In order to give some artificial steering feel, there is a separate hydraulically operated system that tries to turn the steering wheel back to centre position. The amount of pressure applied is proportional to road speed, so that at low speeds the steering is very light, and at high speeds it is very difficult to move more than a small amount from the centre position. As long as there is pressure in the cars hydraulic system, there is no mechanical connection between the steering wheel and the roadwheels. This system was first introduced in the Citron SM in 1970, and was known as VariPower in the UK and SpeedFeel in the U.S. While DIRAVI is not the mechanical template for all modern power steering arrangements, it did innovate the now common benefit of speed adjustable steering. The force of the centering device increases as the cars road speed increases. Electro-hydraulic systems Electro-hydraulic power steering systems, sometimes abbreviated EHPS, and also sometimes called hybrid systems, use the same hydraulic assist technology as standard systems, but the hydraulic pressure is provided by a pump driven by an electric motor instead of being belt-driven by the engine. In 1965, Ford experimented with a fleet of wrist-twist instant steering equipped Mercury Park Lanes that replaced the conventional large steering wheel with two 5-inch (127 mm) rings, a fast 15:1 gear ratio, and an electric hydraulic pump in case the engine stalled. In 1994 Volkswagen produced the Mark 3 Golf Ecomatic, which utilized an electric pump so that the power steering could operate while the engine had been turned off by the computer to save fuel.Electro-hydraulic systems can be found in some cars by Ford, Volkswagen, Audi, Peugeot, Citroen, SEAT, Skoda, Suzuki, Opel, MINI, Toyota, Honda, and Mazda. Servotronic Servotronic offers true speed-dependent power steering, in which the amount of servo assist depends on road speed, and thus provides even more comfort for the driver. The amount of power assist is greatest at low speeds, for example when parking the car. The greater assist makes it easier to maneuver the car. At higher speeds, an electronic sensing system gradually reduces the level of power assist. In this way, the driver can control the car even more precisely than with conventional power steering. Servotronic is used by a number of automakers, including Audi, BMW, Volkswagen, Volvo, and Porsche. Servotronic is a trademark of AM General Corp. 附录 C 历史 已知最早的专利有关的动力转向系统是由弗雷德里克兰彻斯特在英国，在1902 年 2 月。 他的发明是 “导致转向驱动机制，由液压动力 ”。 接下来的设计提出由美国专利局记录 1932年 8月 30日在克拉拉盖利斯，从贝尔蒙，马萨诸塞州。 有与动力转向由查尔斯 F 哈蒙德在底特律的美国，谁提出了类似的专利，其中被提交由加拿大知识产权局录得的第一个出生的，名字记入另一位发明家发明。 克莱斯勒公司推出了第一款商业化的动力转向在 1951 年克莱斯勒帝国的名义 Hydraguide系统。 现在大部分新车的动力转向，由于对前轮驱动的趋势，更多的车辆质量，和更广泛的轮胎 ，所有增加必要的指导工作。 在一些国家，共同将很难在低速行驶机动车辆较重，而重量轻的车辆可能不需要辅助转向的一切权力。 液压助力转向 大多数动力转向系统工作，通过使用液压系统把车辆的车轮。 液压通常由一 gerotor或旋片泵的汽车引擎驱动。 双作用液压缸适用于一队的舵机，从而适用于一扭矩对负重轮转向轴。 到汽缸流控制的方向盘操作阀 ，扭矩更适用于驾驶方向盘，它是连接轴，更流体阀允许通过在气缸，所以更多的力量适用于在适当的引导方向的车轮。 衡量一个适用于方向盘上的扭矩设计用于修复扭杆的督导轴端。 随着方向盘转动，因此没有附加的转向轴，所以也所附扭杆高端。 由于扭杆比较薄，灵活，低端不完全自由旋转，酒吧将吸收一些的扭矩 ；底部的结束将不会旋转尽可能的最高端。 在之间扭杆的顶部和底部旋转的差异，可以用来控制阀，使流体流向汽缸提供指导帮助，在更大的 “扭曲的扭力杆 ”，更将转向援助提供。 由于该泵采用容积式类型，流速它们提供成正比的发动机转速。 这意味着，在发动机转速高，督导工作自然会比在低转速更快。 因为这将是不好的，限制口和流量控制阀是用来直接泵的输出部分回到高发动机转速液压水库。 阿泄压阀也可以用来防止危险的累积压力，液压缸的活塞到达气缸结束。 一些现代的实现还包括一个电子泄压阀，可以减少在舵机作为车辆的速度增加线路功率液压（这是可变动力转向协助已知）。 DIRAVI 在 DIRAVI制度雪铁龙发明，部队把车轮来自汽车的高压液压系统及始终是相同的，不管什么道路速度。 由于方向盘被打开，车轮转向同时向相应角度的液压活塞 。 为了让一些人为