Talking about the steering system of the car chassis
I have already introduced the transmission device and driving system software of the car chassis to you before. This time I want to share the steering system software of the car chassis.
Everyone drives every day, manipulating the steering wheel of the car can make the car drive at the angle you need. Very little research is done on how the steering wheel of the car makes the wheel turn. A series of devices used to change or maintain the driving or backward direction of the car are called Automotive steering system software.
The basic function of the car's steering system software is to manipulate the direction of the car according to the driver's thoughts. According to the difference of steering electric energy, it can be divided into two categories: mechanical equipment steering system software and power steering system software.
Mechanical equipment steering system software
The mechanical equipment steering system software uses human energy as the steering power, in which all the force transmission parts are mechanical equipment, which consists of the steering control organization, the steering gear and the steering transmission mechanism.
The figure shows the composition and layout plan of the mechanical equipment steering system. When the car turns, the driver adds a steering torque to the steering wheel "1", which is entered into the steering gear "5" according to the steering axis "2", the steering cross axis "3" and the steering rotation axis "4". The torque enlarged by the steering gear and the fitness movement after deceleration are transmitted to the steering arm "6", and then sent to the steering knuckle arm fixed on the left steering knuckle "9" through the steering main support rod "7" "8" offsets the left steering knuckle and the left steering wheel it supports. In order to make the right steering knuckle "13" and the supported right steering wheel corresponding to the viewing angle with the offset, a steering ladder shape is also set. The steering ladder is composed of the ladder arms "10, 12" fixed on the left and right steering knuckles and the steering cross support rod "11" which is connected with the ladder arms by ball screws on both sides.
When the driver rotates the steering wheel, the steering torque is entered into the steering gear according to the steering shaft, the steering cross shaft and the turning shaft. The series of components from the steering wheel to the rotating shaft is called the steering control organization.
Steering crank arm, steering main support rod, steering knuckle arm, left/right ladder arm, steering support rod are collectively referred to as steering transmission mechanism. The ladder arm, the steering cross support rod and the front axle form a steering ladder, and its function is to ensure that the left and right steering wheels are shifted according to a certain regularity.
Power Steering System Software
Hydraulic Power Steering System Software (HPS)
The hydraulic power steering system software is a steering system that uses both the driver's energy and the car engine power as the steering electric energy. Under normal conditions, only a small part of the kinetic energy required for the steering of the car is given by the driver, and most of the kinetic energy is brought by the car engine according to the power steering equipment. However, when the power steering equipment fails, the driver should be able to undertake the daily task of steering the car alone. Therefore, the power steering system is generated by adding a set of power steering equipment to the foundation of the mechanical equipment steering system.
The figure shows the composition of a hydraulic power steering system and a plan view of the piping layout of the hydraulic power steering equipment. The parts belonging to the power steering equipment are: steering oil storage tank "9", steering hydraulic oil pump "10", steering pressure regulating valve "5" and steering power cylinder "12". When the driver rotates the steering wheel "1" in the opposite direction (left steering), the steering arm "7" pushes the steering straight support rod "6" to shift. The tensile force of the straight support rod acts on the steering knuckle arm "4", and is successively introduced into the ladder arm "3" and the steering cross support rod "11" to offset. In addition, the steering straight support rod also pushes the rotary vane pump in the steering pressure regulating valve "5", so that the right cavity of the steering power cylinder "12" is connected to the steering oil storage tank "9" with zero liquid level working pressure. The ultra-high pressure oil of the steering hydraulic oil pump "10" enters the left cavity of the steering power cylinder, so the interaction force of the hydraulic machine to the right on the piston rod of the steering power cylinder is increased on the steering cross support rod "11" through the pendulum rod. Also offset it. In this way, the small steering torque applied by the driver to the steering wheel can get rid of the steering resistance torque acting on the steering wheel by the road surface.
Motor Control Electric Power Steering System Software (EPS)
The motor-controlled electric power steering system is simple in structure, light in weight, and has few common faults, which reduces fuel consumption and maintenance costs, and is widely used in commercial vehicles at this stage. Shown in the figure is the software plan of the motor-controlled electric power steering system. When turning, the driver rotates the steering wheel, and the corner sensor sends data signals such as steering and rotation rate to the EPS/ECU on the computer, and the computer accepts data signals such as the corner sensor, speed sensor, and car engine speed sensor. Output different amounts of current, control the steering of the motor and the size of the steering torque, and the torque output by the motor will send the power to the rack steering gear according to the speed reduction, torque increase and direction change of the reducer, and the steering gear will send the power. Give the left and right steering knuckle arms, push the wheel to rotate, and then shake the wheel to complete the steering of the car.
According to the different booster parts, the commonly used electronic power steering is divided into three ways:
1. Steering shaft assist type
2. Transmission gear booster type
3. Worm booster
Advantages and Disadvantages of Electric Power Steering System Software
1. The electronic power steering system software can give the best boost under various driving conditions, reduce the vibration of the steering system software caused by the uneven ground, improve the steering characteristics of the car, and alleviate the low-speed driving of the car. It can improve the steering control force of the car and improve the steering reliability of the car when the car is driving, thereby improving the positive safety factor of the car. And it can be set according to different steering hand force characteristics to meet the needs of different application objects.
2. Because the motor is immediately boosted, and the motor is powered by the battery, whether the EPS can boost is irrelevant to whether the car engine is started or not, and it can be boosted even when the engine is turned off or a problem occurs.
3. The electronic power steering system software is only powered by the motor when steering (unlike HPS, the gasoline pump keeps running even when there is no steering), so it can reduce energy consumption.
4. The electronic power steering system software cancels gasoline pumps, transmission belts, belt pulleys, hydraulic hoses, gear oil and sealing materials, etc. Its parts are greatly reduced compared to HPS, so its quality is lighter and its structure is tighter. Much easier and less noisy.
However, the motor immediately pushes the steering mechanism, which only brings a relatively limited auxiliary range, which cannot be applied to large and medium-sized vehicles; at the same time, there are many electronic components, and the reliability and stability of the system software are not comparable to those of pedal components; The content of sensory information is poor, the operational joy in specific safe driving is greatly reduced, and the cost is high.
steering system of the car chassis