1、 1 附录 A 外文文献原文： In recent years, along with the social life of car motorization, increasing quantities, cause the traffic situation intricate, make drivers to offer the operating frequency increases, driving you need to lighten the fatigue, improve manipulation portability and flexibility, and thus
2、power steering system requirements for more and more is also high. So far, automotive steering system through the traditional mechanical steering system, hydraulic steering system and electric hydraulic steering system and electric power steering system four stages of development, the future is like
3、ly to wire control power steering system development. Now automotive steering system is in hydraulic steering system and electric hydraulic steering system to electric power steering system development stages of transition . 1. the traditional mechanical steering system Traditional mechanical steeri
4、ng system (MS) mainly by steering control agencies, steering gear and steering transmission mechanism 3 parts. Steering control mechanism is the pilot control redirector work institutions, including the steering wheel at the input from components. The steering wheel steering is coming from torque ac
5、cording to certain transmission amplifier and output increases force device, steering the earliest USES is the worm type, later have a screw nut type, rack-and pinion type, circulation ball type and other forms. Steering transmission mechanism is passed to the output torque steering steering wheel a
6、gencies, including the steering wheel from pitman arm of components . When the car needs to change directions, the pilot through turned the steering wheel, steering moment, steering, via steering shaft, horizontal bars and straight bars such as the steering trapezoid arm parts, and to make the day d
7、eflection change of direction. Traditional mechanical steering system is the advantage of simple structure, reliable operation, the production cost is low. Its defect is also very obvious: (1) with the bus speed improvement and automotive quality increases, steering control, turning to more and more
8、 demanding increased the difficulty. (2) is the ratio is fixed, namely Angle transfer characteristics, cause the car cant change the steering response characteristics are unable to control and transmission in the process of steering cannot with speed and lateral acceleration and other parameters of
9、the changes, the pilot must compensate for car before in turn the steering response characteristics of certain operating compensation, such virtually increased the mental and physical burdens driver . 2. hydraulic steering system Hydraulic steering system (HPS) is the traditional mechanical steering
10、 system basis with a set of additional hydraulic booster, generally by oil pump, v-shaped belt wheel, oil injection equipment, power devices and control valves etc. It with hydraulic 2 oil pump is the power, through the movement to promote produced mechanical redirector work. Because the system thro
11、ugh hydraulic works used to promote the traditional mechanical steering mechanism of steering movement so as to reduce the labor intensity, a driver in a certain extent, solve the traditional mechanical steering system caused because of transmission ratio fixed to light and sensitive the contradicti
12、on between. But, this kind of power steering system is driven by the steering wheel rotates the hydraulic system directly change torsion bar is the channel area to provide oiling the instrumentality of variable. Namely the discretion of size and speed boost have no relation with steering Angle, only
13、 concerned. Steering dish of greater perspective, turn the instrumentality of hydraulic systems provide is bigger also. Meanwhile, this system has the following weakness: (1) no matter car turn not to, as long as the engine and hydraulic motor drive ZhuLiBeng will work under the energy, the extra co
14、nsumption engine. (2) the steering characteristics not adjusted, high-speed and same speed dynamical characteristics. In low-speed steering need bigger boost, often for engine speed and low power poor effect, while in high-speed steering need smaller, will boost for engine speed high and power funct
15、ion big, bring about steering too sensitive, that the car manipulation stability becomes poor. (3) the inherent hydraulic system of the hydraulic oil leakage problems and steering noise makes steering comfort, meantime, dramatically reduced environmental pollution. Because of hydraulic steering syst
16、em reliable work, mature technology, can provide the big steering and has been widely used. 3. electrohydraulic power steering system Electrohydraulic power steering system at work steering characteristics can be changed. It basically has two kinds: electric hydraulic steering system (ECHPS) and ele
17、ctric hydraulic steering system (EHPS). Now automotive applications is the largest electric hydraulic booster turn from system. 3.1 electronic control hydraulic power steering system Electric hydraulic steering system (ECHPS) in hydraulic steering system is based on the liquid flow rate increased co
18、ntrol solenoid valves, torque sensor, the wheel speed sensors and steering control unit etc components. Ideally, car in spin to try to deft, request when in cars to different speed operation, which can real-time provide corresponding steering to overcome the running speed to make drivers to resistan
19、ce to manipulate the steering wheel can both lightweight, and have enough way feeling. In steering process, through the torque sensor, speed sensor etc sensing device will shift to rate, speed transfer to parameters such as steering control unit. After decoding, control by electromagnetic valve with
20、 liquid flow speed changing, and change the size of the moment, make grants to individual driver according to speed and driving conditions, changes to manipulate portability and stability to harmony. But at the same time, ECHPS also exist because of oil pump continuous work caused by excess energy c
21、onsumption, the hydraulic system occupies a large space, easy to leak, noise big shortcomings, and increased its speed detection control device. And 3 the control valve of structure than HPS complex and cost is higher, which are mainly applied in limousines and sports by using the car. 3.2 electric
22、hydraulic steering system Electric hydraulic steering system (EHPS) is in hydraulic steering system developed on the basis of. Its characteristic is driven by the engine turns ZhuLiBeng shifted the hydraulic motor drive, and increased its speed sensor, steering angular velocity sensor and steering c
23、ontrol unit etc electricals. The system of hydraulic oil tank, oil pump, motors and steering control unit has integrated in motor oil pump in the group. Work steering control unit according to car of the speed and steering Angle calculated as the input signal output signal, control ideal appropriate
24、 power, motor output ZhuLiBeng driven hydraulic work. Through the hydraulic oil for steering gear provide power. Electrohydraulic power steering system although in hydraulic steering system basis of technology has greatly improved, but the existence of hydraulic equipment are still made the system,
25、such as the hard to overcome shortcomings existing oil leakage, not easy installation and maintenance, etc. Although realized the change, but the dynamical characteristics in hydraulic booster system based on electronic control device increased again, making the system structure is complex, cost inc
26、reases. Because electro-hydraulic steering system technology, may realize the mature electronic-controlled system integration, vehicle as traditional hydraulic steering system to electric power steering system of intermediate technology of transition, in certain time will continue to receive applica
27、tions and development. 4. electric power steering system (EPAS or EPS) Electric power steering system is the traditional mechanical steering system foundation, increased sensor device, electronic control devices and steering mechanism, etc. Its characteristic is to use electric actuators in differen
28、t driving conditions for pilot provide appropriate support. System mainly consists of the electronic control unit ECU, torque sensor, the wheel speed sensors, motor, clutch and the steering assembly etc. Electric power steering system working principle is: the pilot control steering, the sensor will
29、 pilot role in steering wheel torque signal, speed signal, engine speed signal input ECU, ECU of the input signal calculations, inquires the booster form, determine the size and direction target current, so as to control motor current and the direction, by slowing institutions and clutch motor torqu
30、e transfer to steering mechanism will be, so as to provide the proper power； driver When steering system malfunction, EPS system does not support. Dont turn circumstances, motor doesnt work. Electric power steering system can real-time in different speed for car turned to provide different under the
31、 instrumentality of guarantee in low-speed driving car deft and agile, high speed is stable and reliable. Electric power steering system generally consists of mechanical parts and controlling part. Mechanical parts mainly include transmission unit (the clutch, the steering assembly) and execution unit (electrical), etc. Control part mainly according to sensors to speed and torque signal for computing,
