Composition structure of automobile steering system (solution)

The function of the automobile steering system is to control the driving direction of the automobile according to the driver's wishes and ensure that the automobile can drive in the direction selected by the driver. It consists of steering gear with steering wheel and steering transmission device.

Automobile steering system can be divided into two categories: mechanical steering system and power steering system.

Mechanical steering system

The mechanical steering system takes the driver's physical strength as the steering energy, and all the force transmission elements are mechanical. The mechanical steering system consists of steering control mechanism, steering gear and steering transmission mechanism.

Figure 1 shows the composition and layout of the mechanical steering system. When the car turns, the driver applies steering torque 1 to the steering wheel. This torque is input to the steering gear through the steering shaft 2, steering universal joint 3 and steering transmission shaft 4. The torque and deceleration amplified by the steering gear are transmitted to the steering rocker arm 6, and then transmitted to the steering knuckle arm 8 fixed on the left steering knuckle 9 through the tie rod 7, so that the left steering knuckle and the left steering wheel supported by it are deflected. In order to make the right steering knuckle 13 and the right steering wheel supported by it deflect by a corresponding angle, a steering trapezoid is also set. The steering trapezoid consists of trapezoid arms 10 and 12 fixed on the left and right steering knuckles, and tie rods 1 1 with both ends connected to the trapezoid arms through ball hinges.

A series of parts from steering wheel to steering transmission shaft belong to steering control mechanism. A series of parts (excluding steering knuckle) from steering rocker arm to steering trapezoid belong to steering transmission mechanism.

Power steering system

Power steering system is a steering system that uses both driver's physical strength and engine power as steering energy. In general, only a small part of the energy required for steering is provided by the driver, and most of it is provided by the engine through the power steering device. However, when the power steering device fails, in general, the driver should be able to undertake the vehicle steering task independently. Therefore, the power steering system is formed by adding a power steering device to the mechanical steering system.

For heavy trucks with a maximum gross mass of more than 50t, once the power steering device fails, the force exerted by the driver on the steering knuckle through the mechanical transmission system is far from enough to deflect the steering wheel and realize steering. Therefore, the power steering device of this car should be particularly reliable.