Push rod type electric power steering device for commercial vehicle

Abstract

The invention discloses a push rod type electric power steering device for a commercial vehicle. The device comprises a circular ball type steering gear provided with a steering wheel torque and corner sensor, a planetary rolling column screw type electric push rod power steering mechanism and an electronic control unit. The steering wheel torque and corner sensor is used for detecting torque anda steering wheel corner acting on a steering wheel and is arranged on the input end of the circular ball type steering gear, the planetary rolling column screw type electric push rod power steering mechanism comprises a motor, a synchronous belt speed reduction mechanism, a planetary rolling column screw transmission pair, a linear guide rail, a push rod and the like, a motor output shaft is connected with a small belt wheel, a motor outputs torque and transmits the torque to a planetary rolling column screw through a synchronous belt, a large belt wheel inner hole is connected with a screw inthe planetary rolling column screw, the output torque is transmitted and amplified through the planetary rolling column screw transmission pair, and a steering rocker arm shaft is pushed to rotate. One end of the planetary rolling column screw type electric push rod power steering mechanism is connected with a steering rocker arm, the other end of the planetary rolling column screw type electricpush rod power steering mechanism is connected with a vehicle frame, through planetary rolling column screw transmission, large thrust steering assistance is obtained, and pure electrification and intelligence of a heavy commercial vehicle steering system can be achieved.

Description

[0001] Technical field [0002] The invention relates to the technical field of automobile steering systems, in particular to a push rod type electric power steering device for commercial vehicles. Background technique [0003] At present, the steering gear for vehicles is mainly divided into rack and pinion type and recirculating ball type, which are used for passenger cars and commercial vehicles respectively. Traditional power steering is hydraulic power steering, and the amount of power assistance is controlled by a slide valve or a rotary valve. Traditional hydraulic power steering has the following problems: the power assist characteristics cannot be adjusted and controlled in real time with the vehicle speed, and it is difficult to coordinate the contradiction between the lightness of low-speed steering and the "road feel" of high-speed steering; There are oil leakage and maintenance problems in the system itself, which increases the maintenance cost, and the hydraulic...

AI Technical Summary

Problems solved by technology

Traditional hydraulic power steering has the following problems: the power assist characteristics cannot be adjusted and controlled in real time with the vehicle speed, and it is difficult to coordinate the contradiction between the lightness of low-speed steering and the "road feel" of high-speed steering; There are oil leakage and maintenance problems in the system itself, which increases the maintenance cost, and the hydraulic oil will also pollute the environment; components such as oil pumps, pulleys, and hydraulic pipelines take up space and are not easy to arrange

Among them, only the torque sensor is designed in the recirculating ball steering gear, which cannot realize the active return performance, and the torque output by the booster motor drives the rocker shaft to rotate through the reduction mechanism and the screw nut transmission pair, while the screw nut drive in practical applications It is difficult for the pair to bear a large enough load, and its strength and life cannot meet the requirements of heavy-duty commercial vehicles

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