Steering mode of vehicle steering mechanism

Wheeled vehicles have three steering mechanisms: axle steering, wheel steering and articulated steering. Axle steering is used in early cars and some modern full trailers. Although several axles intersect at one point during steering, this steering mode is not suitable for high-speed vehicles because of excessive front and back displacement of wheels, large steering resistance and large tire wear.

/KLOC-After Aikman invented the trapezoidal linkage steering mechanism at the end of 0/9, wheel steering has been widely used in automobiles. In order to make the structure simple, most vehicles use front wheel steering. When steering, make all wheels move around the same instantaneous steering center as much as possible to ensure that the steering wheel does not slip. Because the turning radius of each steering wheel is different, its angle is also different. The following relationship should be maintained between the angles of the inner and outer steering wheels, where θo is the outer steering angle, θi is the inner steering angle, L is the wheelbase, and μ is the track.

The trapezoidal linkage mechanism can approximately satisfy this relationship. The steering rod which is matched with the vehicle suspension and connects the wheel and the steering gear is integrated and segmented. The bar system is generally arranged behind the front axle and sometimes in front of the front axle. Some vehicles use rear wheels to steer because the front axle is a drive axle, the load is heavy or there are special requirements for maneuverability. 3-axle, 4-axle or multi-axle vehicles with the same wheelbase can also use front and rear wheels to steer at the same time (some 4-drive tractors use all-wheel steering, and can use front and rear wheels or four-wheel steering at any time according to the situation, even crab walking).

1, the steering function of articulated vehicle is similar to axle steering, that is, the wheels have no steering function, and the articulated part of the vehicle is pushed by hydraulic or pneumatic mechanism to steer the vehicle. Articulated vehicles are mostly off-road vehicles or construction machinery driving on soft ground with low speed, so this steering mode can be adopted. 2. The tracked vehicle can turn as long as the left and right track speeds are different. So one side can brake and turn in place. 3. Large cars, buses, trucks with front axle load exceeding 4 tons, and articulated vehicles mostly use hydraulic power-assisted steering mechanism. The requirements for various power-assisted mechanisms are: reducing steering hand force and having a sense of road; When the power assist system fails, manual steering can still be used. Overweight vehicles should also have emergency energy storage or electric steering pump to keep the steering function for a short time under any circumstances.