As one of the most important and indispensable systems in the process of forming a car, the steering system of a car has always been an important system for major car manufacturers to optimize and upgrade. The steering system of a car can directly affect the driving experience of the driver, and the steering system is important for The steering system of a car can directly affect the driving experience of the driver, and the steering system has an important significance for the safe driving of the car. According to the investigation and analysis of many traffic accidents, there are few accidents caused by the failure of the steering system. According to the investigation and analysis of many traffic accidents, there are few accidents caused by the failure of the steering system.

Accordingly, the steering principles of general-purpose vehicles are analyzed, and the troubleshooting of the steering system is studied. The study of steering system troubleshooting is also carried out. In the present time when vehicles are becoming more popular, high-speed and traffic accidents are frequent, it is important to analyze the operation principle of the steering system of the car itself and to study the troubleshooting of the steering system. The analysis of steering system operation and the study of troubleshooting methods are of great importance to reduce the probability of traffic accidents.

1 Steering System

The steering system is a series of dedicated working devices that are specifically used to change or maintain the normal driving or backward direction of the car.

1) The basic composition of the steering system

At present, the steering system of automobiles is in the transitional stage of the development of two kinds of steering systems: mechanical power steering and electro-hydraulic power steering electric power steering system. The traditional mechanical steering system mainly consists of a steering mechanism, steering gear, and steering transmission mechanism. The steering mechanism is mainly composed of the steering wheel, main steering shaft, steering column, and some supporting devices. The steering gear is mainly used as a class of components, which can be classified into worm gear crank finger pin type, rack and pinion type, and recirculating ball type according to their different classifications. On the one hand, the steering gear can amplify the steering force, on the other hand, it can turn the steering power on the steering wheel into the regular oscillation of the steering rocker or into the linear regular motion of the rack and pinion shaft. The steering gear is fixed on the car, and its steering force can change the direction of the car transmission by its own function. The steering transmission mechanism plays the medium function of the vehicle steering system, transmits the steering power output from the steering gear to the wheels through its own medium function, and makes the wheels deflect in the corresponding direction according to the force coming from above.

2) Working principle of the steering system

Automotive steering systems are divided into mechanical hydraulic power steering, electronic hydraulic power steering, and electric power steering which will be applied in the future. The following is an analysis of these three types of hydraulic steering systems.

(1) Traditional mechanical hydraulic power steering system has been gradually marginalized in the field of automobile development. This type of system consists of a hydraulic pump, pressure control valve, drive belt, and other conventional components, and has many drawbacks in actual operation. The main criticism is its unnecessary energy consumption. The mechanical hydraulic power steering system is mainly composed of piping, cylinders and hydraulic pumps, etc. In order to maintain relatively constant pressure, the design principle subjectively ignores the steering needs of the main shaft, whether or not the steering, the system always maintains a constant power. This continuous working condition is amazing for the unnecessary consumption of energy. And when the speed of the car is low, the power output of the hydraulic pump must become larger in order to operate properly, resulting in unnecessary waste of energy. The pressure of the hydraulic pump itself is huge, which is also easy to causes damage to the booster system. In the current automotive market, there are still many economical cars in the application of such steering systems.

steering system

(2) Electro-hydraulic power steering system does not completely solve the criticism of the mechanical hydraulic system, but there are further upgrades in the original system, which can greatly reduce unnecessary energy consumption. The electro-hydraulic power steering system has little change compared with the components of the mechanical system, mainly increasing the electric pump, power steering sensor, etc., and taking down the traditional V-shaped rotating belt, in which the steering control and electric pump are integrated into one structure. The electro-hydraulic system has made technical progress and breakthrough compared to the mechanical system, relatively solving the mechanical system’s low-speed steering force phenomenon while reducing unnecessary energy consumption. When the electro-hydraulic system works, it no longer relies on the belt for driving but uses the more efficient electric pump. Inside the electro-hydraulic system, the electronic control unit relies on the vehicle’s driving speed, direction, steering angle, and other data to calculate the optimized energy supply rate and unit of the system in different driving conditions. The mutual transmission of the electric pump and electronic control unit constitutes a more optimized electro-hydraulic power system. This system solves the mechanical steering system in the low-speed steering in a large direction when the rotation force and energy consumption are too large; at the same time when the car in the high-speed driving state, the hydraulic control unit drives the hydraulic pump to reduce its own operating speed, not only will not affect the high-speed turning driving state, but also to maximize the savings of unnecessary consumption of energy.

(3) EPS, the Chinese name for the electric power steering system, is the future direction of the development of automotive steering systems, but also a period of time in the future will be vigorously promoted automotive steering systems. The electric power steering system solves the biggest defects of mechanical power systems and electronic power systems and can save more than 50% of energy consumption at the maximum. The electric power steering system uses the power generated by the electric motor itself to assist the driver in the steering work. In terms of components, the electric power steering system replaces the power steering sensor used in the electro-hydraulic system with a torque sensor and adds more advanced components such as a reduction gear and a mechanical steering gear. When the vehicle is running, the torque sensor transmits the torque and direction of the steering wheel to the electronic control unit, which automatically generates the corresponding next-level commands based on the torque and direction, and outputs them to the motor controller to produce power steering. The biggest highlight of the electric power steering system is that when the driver does not steer, the system does not work when it does not receive a steering signal and starts at any time in a dormant state, which saves the maximum energy consumption of the car operation.

2 Steering system troubleshooting

1) Steering force

The problem of steering force usually occurs in the mechanical hydraulic power steering system, but less in the electronic hydraulic power steering and electric power steering system. When this happens, you should first check whether the vehicle is short of oil, whether the steering belt is normal, and whether the air enters the system. Vehicle oil shortage and belt slippage will lead to steering power pump can not work normally; system into the air will be due to its compression principle resulting in the system can not play the role of power. Troubleshooting methods are to refuel and replace the belt, and exhaust air and the system can be restored to normal. If the above is no problem, the steering fault has not been solved, should be in the throttle valve and pressure control valve all open state to measure the vehicle idle static oil pressure, if less than or equal to 1500kPa, the oil pump is no problem. Check whether the oil pipeline between the steering gear and the oil pump is normal. Measure the oil pump unloading pressure at idle speed, if the pressure is low, check whether the oil volume valve is normal. If all of the above are OK, check the steering wheel power, the difference between left and right should not be greater than 2.9N, if it is greater, check the oil cylinder line. If the value is within the allowable range, check whether the rack shaft, rack guide screw, and steering control valve are normal.

steering system

2) Vibration when steering angle is maximum

Check whether the power steering is faulty, check the guiding screw adjustment problem, if it is normal, check whether the driving belt is slipping, and replace it in time.

3) Steering jump back

When the vehicle is steering, the steering wheel jumps back. Firstly, measure the pump pressure with the two valves (pressure control valve and throttle valve) closed, if it exceeds 500kPa, check whether the flow control valve is abnormal. The steering oil pump can be replaced to deal with it.

4) Unstable operation and delayed steering

The main manifestation is the dead zone of steering wheel rotation, and the car is unstable when driving in a straight line. Firstly, check the guiding screw and fine-tune it appropriately; secondly, check whether the conveyor belt is abnormal and replace it according to the situation; again, check whether there is a lack of oil and whether air enters inside the system causing the abnormality. And promptly refuel the oil tank to eliminate the air.

5) Abnormal noise of power steering system

It is mainly reflected in the normal driving process of the vehicle steering system’s abnormal noise. Troubleshooting method: Firstly, dismantle the oil pump conveyor belt to observe the situation, if there is still noise, it is determined that the torque converter or oil pump is working abnormally. Secondly, if there is no problem, check whether the noise comes from oil pulsation, which is a normal phenomenon. Finally, check whether the high-pressure hose is frictionally broken, and if it exists, fix it twice or replace it and adjust the position.

6) Oil Leakage

There is oil leakage outside the steering system. First, check the steering system independent oil tank, and check the steering gear, oil pump, oil pipe, and its joints for abnormalities. According to the oil leakage, replace the equipment and tighten it twice to deal with it properly.

7) The power steering system has a trembling sound

First of all, check whether the size of the swing to the shaft, if the problem is replaced in time; secondly, check whether the wire plug is adjusted properly; again, if the trembling sound only appears during the operation of the vehicle, the sound is normal when the steering wheel is turned off. Finally, check whether the cross-tie rod and ball pin are a loose phenomenon, cross-tie rod, and ball pin fixation needs to be checked regularly, if loose, then the second reinforcement or replacement parts.

3 Conclusion

It is a basic quality that every driver should have to master the basic knowledge of automobile construction, understand the basic principles of automobile subsystem operation, be familiar with the role of each component in the system, and have the ability to solve automobile troubles independently. The analysis of the principles and troubleshooting methods of the automotive steering systems can help improve the driver’s ability to deal with emergency accidents and provide a strong reference for the development and innovation of the steering system.