With the continuous development of society, the automobile has become a very common means of transportation in people's lives, and the performance of the steering system of the car has largely determined the importance of the ease and comfort of the car's operation and the stability and smoothness of reliable driving. In recent years, the theory and application of linear motor have been rapidly developed, and its application field has been expanding. Now the application of linear motor in automotive steering field is discussed and analyzed in conjunction with the operating principle of the corresponding mechanism of automotive steering device.
First, the steering wheel requires that it be light and flexible and have a stable sense of operation.
As the wheel turns, the friction damping between the tire and the ground increases with the speed reduction. That is, when the car is steering at a low speed, it will be very laborious to control the steering wheel without helping the traditional mechanical steering system. For this reason, the power steering system has basically been adopted. And the control requirement for steering power decreases as the speed increases. When the speed is very high, the steering wheel will be very light, in order to avoid the slightest interference with the steering wheel and cause the car to deviate from its direction, reducing the phenomenon of "thugs" caused by the impact of the uneven road impact steering wheel to the steering wheel. At the end of the steering, the steering wheel can have an automatic positive function to keep the car running in a straight line, so that the driver can always maintain an appropriate "road sense" through the steering wheel during the steering process. When the car is driving at high speed, it hopes to have a "reverse" aid to the steering system, that is, to increase the damping of the steering system appropriately.
Second, it has a high sensitivity to steering controls and can simplify its structure to reduce energy consumption.
When steering the steering system, the wheel is required to respond quickly so that the body can turn in time. In addition to minimizing the empty stroke gap of the steering system, the power control device used for steering power is required to respond quickly. At present, the power steering systems used mainly include hydraulic pressure, air pressure and electric power. The first two have the disadvantages of large energy consumption and slow response. The existing electric power steering system EPS uses a rotary motor, which needs to pass through mechanical mechanisms such as electromagnetic clutches and gear deceleration drives. There are also many problems such as complicated mechanisms, large space occupancy, and slow response speed. According to the steering mechanism to drive the steering arm of the transverse pull bar are left and right linear movement and other characteristics, for this reason the use of linear motor directly drive the left and right transverse pull bar, so that the control is more direct and the dynamic response is faster.
Third, require the steering wheel to move correctly and steadily
That is, the deflection angle of the inner and outer steering wheels and the differential speed ratio of the driving wheels are required to be correct and stable. The ratio of the two is always related to the angle of the steering wheel to ensure that each wheel only rolls without sliding during steering. phenomenon. By analyzing the motion process of the inner and outer steering wheels and driving wheels when the car is turning, in order to ensure that the wheels only roll without sliding, it is required that the four wheels should rotate around the same center. Let L be the wheelbase of the car, B be the wheelbase of the car, and α and β be the deflection angles of the outer and inner steering wheels, respectively. At the same time, the inner and outer drive wheels also need to meet the corresponding differential conditions. In order to meet the deflection angle requirements of the inner and outer steering wheels, the trapezoidal or non-parallelogram relationship between the left and right transverse lever and the steering arm of the steering mechanism needs to be made. This is also a common use of various steering systems. Basic method. In order to meet the requirements of driving wheel differential speed, two kinds of mechanical differential speed and electronic differential speed are used. Mechanical differential speed is a common method used in traditional automobiles. Its mechanism is large and complex. The electronic differential system EDS is implemented using electronic control and has many advantages. With the development of electric vehicles, especially the application of hub Motors, it will be the development direction of automotive drive wheel differential control.
Minimize the turning radius and improve the stability of high-speed steering
In order to reduce the turning radius of low speed steering, it is convenient to park at low speed or narrow road steering; As well as improving the driving stability of high-speed steering or when the lateral wind is acting, it also needs to use high-performance four-wheel steering to meet.
Through the above analysis, according to the characteristics of the steering mechanism driving the steering arm, the horizontal pull rods are all left and right straight movements, in order to improve the fast response of the steering system and meet the corresponding support requirements at different speeds.
The intuitive feature of linear Motors is that direct linear motion is generated. By directly driving the load, high-precision position positioning control can be achieved in different ranges from high speed to low speed. There is no direct contact between the actuator(primary) and the stator(secondary) of the linear motor. Both the stator and the actuator are rigid parts, so as to ensure the soundness of the linear motor movement and the high rigidity of the core moving parts of the overall mechanism. Main features: compact structure, small power loss, high speed of fast shift, high acceleration, high speed.
According to these characteristics of linear Motors, kissing can directly drive the two kinds of automotive steering system control mechanisms of the left and right transverse rods. Tongmao Linear Electric will make unremitting efforts to promote the development of China's industrial drive industry and is committed to becoming a reliable supplier of linear motors for customers. Continue to create value for customers.