1. The rear-wheel steering
The so-called rear-wheel steering means a car when cornering, in addition to providing a steering force and the front wheel steering direction other than the rear wheel can also have a certain degree steering angle. Although the angle is very small, but to a certain extent, can improve vehicle maneuverability. Although at the time of exercise of such a small low-speed rear-wheel steering angle does not seem to have much effect, but when traveling at high speed, such a small steering angle can play a crucial role. When the vehicle is capable of turning the current vehicle speed to determine excessive steering of the vehicle or understeer, which we generally think the main reason is the Citroen product caught when turning the resistance, and not roll or flick based.
is not arranged in a complete rear wheel steering mechanism, but merely suspended with a rear wheel suspension arranged between a vehicle body and a number of cushion rubber, the rubber is suspended to the vehicle body by a flexible connection, since the presence of certain rubber elasticity, within the elastic limit and have a very high strength, so that during turning of the vehicle, rear suspension connecting point of the rubber cushion can be some degree of elastic deformation under the action of lateral force. So as to drive the wheel toe angle change do certain angle. Then the rear wheels as the steering wheel is able to do a small angle turned. The steering angle depends on the hardness of the rubber pad. The softer the rubber, the greater the steering wheel angle variable, but to reduce the differential stiffness of the suspension stability; the harder the rubber cushion, the rear wheel steering angle is smaller, but the suspension stiffness, high stability. So the design needs to weigh the pros and cons, do focus adjustment based on the actual use of the car.
for an automobile brand
Peugeot – Citroen series, SAAB, BMW 7 Series, Infiniti FX50, Nissan GTR, independent brands have Ruiqi G5, Great Wall Hover H6 [ principle 123]
principle
rear wheel steering servo technology is actually very simple, Creative designer with a complex structure is not mdash; mdash; mdash; ldquo; show front and rear wheels toe rdquo ;, reached a classic effect:
(1) When the steering wheel before the show. If the suspension system design so that the ground reaction force to the tire after the tire induced steering wheel and an opposite direction i.e. the rear wheels before the exhibition under load, which would produce a moment that the reinforcing rotation angle becomes small transient turning center, oversteer increases significantly at low speeds.
(2) steering the rear wheel toe. If the suspension system design so that the ground reaction force to the tire rotational direction induced Like the front wheel of the rear wheel, i.e. so that the rear wheels toe transient turning radius becomes large to increase an understeer under load, which can guarantee a stable direction , especially in high-speed cornering stability. From the construction point of view, the rear elastic connection between the assembly and the car body, not only can reduce the impact of the suspension of the vehicle body, and when the steering traveling in a road surface reaction force acting at the wheel side before and after deflection from the elastic pad is elastically deformed, the entire rear wheel assembly in the same direction as the front wheels with a small deflection angle, thereby increasing understeer cars, automobiles greatly improved driving stability and steering performance.
Use
using a vehicle rear servo techniques may be at a higher speed, the steering is completed more stably than other models when cornering. Here, even more significantly, this technique is extremely simple to achieve, but because this is Citroen patent, other manufacturers can not be used, thus improving or give up this point, or using more complex and expensive technology to achieve such the cost of the car will increase a lot.
In fact, the rear-wheel steering only works if the turn. Because the car is almost no pure straight line when traveling, so, in fact, at almost any time, this technology will make the running of the vehicle more stable, easier to manipulate, and the cost has not been increased. Beverly Elysee and about one hundred thousand of these models, you can easily run to 200km / h and still very stable, does not float is not biased, it is good Citroen car chassis characteristics of the decision at highway speeds, which also includes a rear wheel steering servo credit. Edit this paragraph classic maneuverability and comfort
ldquo; rear-wheel steering rdquo; vehicle technology gives excellent adhesion properties of the ground, may be largerLarge reduce vehicle rear seat occupants of the roll force, the vehicle during cornering, the rear wheel deflection automatically with a slight angle, even when a sharp turn is very smooth and difficult to drift or roll, to ensure the vehicle comfort and safety of passengers, allows the driver to keep cool in many cases. In the case of an emergency dodge, high-speed turns and so it can play a role, but not for such a suspension system for a vehicle, if the same speeds, the rear of the car may have been hit on the cliff.
The rear-wheel steering Saab
is almost contemporary Citroen, Saab Saab developed ReAxsreg; chassis systems. The system ensures precise steering, can greatly improve the stability of the track, in the case when the high speed even at heavy braking. When using the turning steering wheel slightly to assist smooth cornering of the vehicle body, holding driving track. After the independent multi-link suspension with, in the sports car chassis tuned to provide more powerful performance and cornering stability with your. After the Saab ReAxs passive suspension in the rear wheel steering shaft using a ball and heel rod sections (without using the inner sleeve and the outer rubber suspension), the wheel movement can be better controlled. Therefore, when cornering the load, the elastic characteristics of the motion of the rear axle for the rear wheels will cause the two small deflection in a direction opposite to the steering input, i.e., outside the outer ring tilt, tilt inner wheel. The case where the driving speed and the turning radius (which will change the load of the rear axle), a front wheel steering movement once typically deflect a small but significant percentage of about 1 degree to the rear wheel. This is sufficient to prevent excessive understeer. Help to follow its rear wheel (not the car nose) direction. For the driver, which would allow the car a better balance, make driving more fun, can help in steering the car to be closer to the steering input and reactions.
Currently, the application of the rear-wheel steering technology manufacturers also limited to two SAAB and PSA. And a sign of domestic and Citroen have phased out rear servo steering technology trends. The technology of the future does not look bright. But the owners bought with rear wheel steering servo technology vehicles do not have to worry, because the technology is simple, manufacturers of repair and maintenance certainly can be guaranteed.