Since the power steering device makes the steering operation flexible and light, the flexibility of selecting the steering gear structure when designing the automobile is increased, and the impact of the road surface on the front wheel is absorbed, so it has been widely used in automobile manufacturing in various countries. use.
<br /> Insufficient conventional power steering device <br /> Power steering devices are classified into conventional power steering devices and electronically controlled power steering devices according to different control methods.
However, the conventional power steering device has a fixed magnification. In the design of the power steering device, there is a certain defect: if the fixed magnification of the power steering device is determined based on the force of the car rotating the steering wheel under the parking state or the low speed running state, then When the car is driving at a high speed, this fixed-magnification power steering device will make the force of turning the steering wheel too small, which is not conducive to the direction control of the high-speed car (or vice versa, if the car is driven at a high speed, Determining the fixed magnification of the power steering device for the design basis, then turning the steering wheel when the car is stopped or at low speed
It will be very difficult.
<br /> Advantages of Electronically Controlled Power Steering Devices <br /> The application of electronic control technology in automotive power steering devices can achieve satisfactory results in driving performance. That is, the car can make the steering light and flexible at low speed (when steering in the middle and high speed regions, it can ensure the optimal power magnification and stable steering feel, thereby improving the steering stability of high-speed driving.
(electronic control power steeringEPS)(EPS)(EPS) Electronic control power steering (EPS), referred to as electronically controlled power steering, can be divided into hydraulic electronically controlled power steering (hydraulic EPS) and electric electronically controlled power steering according to different power sources ( Electric EPS). EPS The hydraulic EPS is based on the traditional hydraulic power steering device, and a solenoid valve, a vehicle speed sensor and an electronic control unit for controlling the liquid flow are added. The electronic control unit controls the solenoid valve to realize the steering power magnification according to the detected vehicle speed signal. Continuously adjustable to meet the steering assist requirements at high and low speeds. EPS The electric EPS uses a DC motor as a power source. The electronic control unit controls the magnitude and direction of the motor torque according to signals such as steering parameters and vehicle speed. (The torque of the motor is increased by the electromagnetic clutch through the speed reduction mechanism, and the force is applied to the steering gear. In order to get a steering force that is compatible with the working conditions.
<br /> Features of Electric Power Steering System <br /> Electric power steering system applies the latest power electronics technology and high-performance motor control technology to the steering system of the car, which can significantly improve the dynamic performance and static performance of the car and improve the comfort of the driver during driving. Sex and safety, reducing environmental pollution, etc. Therefore, once the system is proposed, it has been valued by many big car companies, and developed and researched. In the future steering system, electric power steering will become the mainstream of the steering system. Compared with other steering systems, the outstanding advantages of this system are reflected in :
1. 1. Fuel consumption.
The hydraulic power steering system requires the engine to drive the hydraulic oil pump, so that the hydraulic oil keeps flowing, and some energy is wasted. EPS In contrast, electric power steering (EPS) requires the energy provided by the motor only when steering operations are required, either from the battery or from the engine. Moreover, the energy consumption is related to the steering of the steering wheel and the current speed of the vehicle. , When the steering wheel does not turn, the motor does not work. When steering is required, the motor starts to work under the action of the control module, and outputs torque of corresponding magnitude and direction to generate the assisting steering torque. Moreover, when the system is turned in the car. The maximum steering torque is output, and as the speed of the car changes, the output torque also changes. on-demand The system truly achieves "on-demand power" and is a true "on-demand" system. When the car is started in a cold winter, the traditional hydraulic system reacts slowly until the hydraulic oil is warmed up before it can work normally. -40 Since the electric power steering system is designed without relying on the engine and without the hydraulic oil pipe, it is not sensitive to cold weather, and the system can work even at -40 ° C, so a quick cold start is provided. Since the system does not have warm-up during start-up, energy is saved. 2.5%5.5% The hydraulic pump is not used, the parasitic energy loss of the engine is avoided, and the fuel economy is improved. The vehicle with the electric power steering system and the vehicle with the hydraulic power steering system show that the electric power steering is provided without turning. The system's national fuel consumption is reduced by 2.5%, and fuel consumption is reduced by 5.5% when using steering. http://www.qcwxjs.com/ Http://www.qcwxjs.com/
2. 2. Enhanced steering followability.
In an electric power steering system, the electric booster is directly connected to the power assist mechanism to directly use its energy for steering the wheels. The system utilizes the action of an inertial damper to greatly reduce wheel reversal and steering front wheel sway. Therefore, the anti-disturbance capability of the steering system is greatly enhanced. Compared with the hydraulic power steering system, the rotational torque is generated in the motor, and there is no steering hysteresis effect of the hydraulic assist system, which enhances the following performance of the steering wheel to the steering wheel.
3. 3. Improved steering return characteristics.
To this day, the development of power steering system performance has reached its limit, and the positive return characteristics of the electric power steering system have changed all of this. When the driver releases the steering wheel by an angle and then releases it, the system automatically adjusts to return the wheel to the center. The system also allows engineers to use software to adjust design parameters to the maximum extent to achieve optimal return characteristics. From the lowest speed to the highest speed, a cluster of positive characteristic curves can be obtained. Through flexible software programming, it is easy to obtain the torque characteristics of the motor at different speeds and different vehicle conditions. This torque characteristic enables the system to significantly improve the steering capability and provide a steering return characteristic that matches the vehicle dynamic performance camera. In the traditional hydraulic control system, to improve this characteristic, it is necessary to modify the mechanical structure of the chassis, which is difficult to achieve.
4. 4. Improved handling stability.
The stability characteristics of the car are tested by means of excessive steering of the car at high speeds. 100km/h With this method, an excessive corner of the car that is driving at a high speed (100km/h) forces it to roll, and in a short self-return process, the car is more stable due to the use of microcomputer control, driving The staff has a more comfortable feeling.
5. 5. Provide variable steering assistance.
The steering force of the electric power steering system comes from the motor. Through software programming and hardware control, variable steering forces can be obtained covering the entire speed. The amount of variable steering force depends on the steering torque and the speed of the vehicle. Whether it's parking, low speed or high speed, it provides a reliable, controllable feel and is easier to operate in the yard. For conventional hydraulic systems, variable steering torque is very difficult and expensive, and additional controllers and other hardware must be added to achieve variable steering torque. However, in an electric power steering system, the variable steering torque is usually written into the control module, which is obtained by rewriting the software, and the cost is small. http://www.qcwxjs.com/ Http://www.qcwxjs.com/
6. 6. Adopt "green energy" to meet the requirements of modern automobiles.
"" The electric power steering system uses the "cleanest" power as the energy source, completely bans the hydraulic device, and there is no leakage of liquid oil in the hydraulic power steering system. It can be said that the system conforms to the trend of "greening". The system avoids contamination because it has no hydraulic oil, no hoses, oil pumps and seals. The polymer used in the hydraulic steering system tubing cannot be recycled, which is easy to pollute the environment.
7. 7. The system has simple structure, small occupied space, convenient layout and superior performance.
Because the system has a good modular design, there is no need to redesign, test, and process different systems, which not only saves costs, but also provides great flexibility for designing different systems, and is easier to assemble. . Since there are no oil pumps, tubing and pulleys on the engine, there is more room for engineers to design the system, and the control module of the system can be designed with the rack and pinion or separately designed, and the space utilization of the engine components is extremely high. . The system eliminates the need for pulleys and oil pumps on the engine, leaving room for other components. Many consumers are very concerned about the maintenance and maintenance of the vehicle when buying a car. A car equipped with an electric power steering system has no oil pump and no hose connection, which can reduce many worries. 53% In fact, in the traditional hydraulic steering system, the accident rate of the hydraulic oil pump and hose accounts for 53% of the total system failure, such as hose leakage and oil pump leakage.
8. 8. The production line is well assembled.
The electric power steering system does not have the oil pump, oil pipe, flow control valve, oil storage tank and other components required by the hydraulic system. The number of parts is greatly reduced, the assembly work is reduced, the assembly time is saved, and the assembly efficiency is improved.
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