The previous car had no direction to help. In the family car, the simple mechanical steering made people feel unhappy.
For female drivers, turning the steering wheel can consume a lot of physical energy, which is not easy at all.
The most common steering structure on automobiles today is a rack-and-pinion steering structure. Its working principle is as follows:
When the steering wheel is turned, the steering gear drives the steering rack to move left and right, and the steering tie rod changes the direction of the wheel to control the car to turn left and right.
The advantages of pure mechanical steering for rack and pinion gears are low cost, simple structure, clear road feel, and strong reliability. But it's really heavy!
Now even tractors are using hydraulic power steering. What is the use of this iron rod?
Hydraulic assistance As the name implies, it is to add a set of hydraulic boosting system to the original structure of the machine. Its structure is as follows:
The working principle of the hydraulic power steering system is that the hydraulic pump (driven by the engine belt) provides pressure to push the piston in the power cylinder to generate the auxiliary power push-pull steering rod, allowing the driver to turn more easily.
Its advantages are obvious, such as a clear sense of road and a large steering force;
However, the shortcomings are fatal, that is, it consumes engine power at all times and at high speeds, because of too much steering power, there is a lot of movement in the front wheel of the steering wheel. This is true for high-speed cars. very dangerous.
So the electrohydraulic booster should be born from time to time!
Actually, the principle of electrohydraulic boosting is similar to that of mechanical hydraulic pressure. It merely replaces the oil pump with electric, so that it does not consume engine power when it is not working, and after adding several sensors, it can adjust the pump flow according to the speed of the vehicle. To change the size of the assist.
The lower the vehicle speed, the greater the steering assistance. This will allow the vehicle to turn around more flexibly and steer it. The higher the vehicle speed, the lower the steering assistance will be to maintain driving stability.
If it's someone who is as easy as I am, it must have been very satisfied with this steering system. It can even be described as perfect!
But our smart car engineers don't think so; they think hydraulic lines take up a lot of space and their structure is complicated.
So more advanced electric power is available~
This system is very perfect so far, the full name is called electric power assist (English name ElectricPowerSteering) English abbreviation EPS
The working principle of the electric booster system and the hydraulic boosting force are basically the same. The difference is the following three points;
(1) The torque sensor replaces the control valve.
(2) The assist motor replaced the hydraulic cylinder.
(3) Added EPS control device.
The working principle is: During driving, a series of calculations, such as steering wheel rotation angle and road steering resistance, are detected by the sensor to precisely assist the steering system, that is, variable assistance with speed!
The most scientific is that the driver can also customize the steering damping of the steering wheel!
This is nothing. With the development of technology, the car can also connect other systems such as radar and camera with the electric power assistance system to make black technology functions such as automatic driving, automatic parking, and lane keeping.
In this way, electronic assistance is not only more fuel efficient than hydraulic boost, but also more functional, and there are still more black technologies still in development! So now the family cars generally use electric power assist (EPS).
