Design And Analysis On Mechanical Turning Characteristics Of Four-Wheel Steering Vehicles

Recently, due to the rapid development of the logistics industry, the needs of the freight, heavy-duty vehicles is increasing. The performance of the steering system directly decides the multiracial car at low speed tactical flexibility and high-speed operation handling stability and ride comfort. The application of mufti-axis steering technology makes its turning radius is controlled within a reasonable range, applicable performance greatly improve work efficiency, reduce tire wear, easy car sharp turns at high speed from one lane to another lane to move to adjust. Turn around and reduce the turning radius, as well as reduce the difference of the radius of the inner wheel to improve traffic safety. The ideal multi-axis steering system should be in full compliance with the Ackerman steering principle.The four institutions can not fully meet the Ackerman steering principle. A steering mechanism can fully meet Ackerman steering principle was carried out. A cam-linkage combined mechanism consisting of multi-axis steering mechanism was proposed. Furthermore, to The most common two axis car (ie, four-wheeled vehicles),the design of the steering mechanism in full compliance with Ackerman steering principle was proposed.The main work of this paper are as follows:(1) The need to meet the multi-axis steering Ackerman steering conditions were summarized by analyzing the vehicle was in the case of a shaft turning, two-axis turning and three-axis steering wheels to meet Ackerman steering conditions. Steering in the non-skidding under ideal conditions, first, the axis of all the wheels intersect at one point, second, all the same side of the wheel to achieve the same trajectory steering. third, vehicle to achieve a circular motion around a fixed point in situ. In addition, compared with the traditional front wheel steering to achieve multi-axis turning its turning radius is reduced by half.(2)To the four trapezoidal steering mechanism and flat-six-bar steering mechanism.13in line with the steering mechanism required six types of institutions were elected by a comprehensive analysis of type. Did the type topological analysis of the Watt-Ⅱ six-bar mechanism, and used matlab to optimized design a reasonable length of rod and three rod angle. Pointed out that the four institutions can not meet the Ackerman steering principle and the plane six institutions there is a big error, can not fully meet the Ackerman steering principle applied to the steering mechanism.(3)Design a new steering mechanism based on trapezoidal steering mechanism and Watt-Ⅱ type six-bar mechanism. Completed the outline of the design of the disc-shaped cam and mobile cam with the software matlab, and solidworks. A cam-rod combined steering mechanism is to completely satisfy the Ackerman principle steering was designed.(4)A rack and pinion mechanism to achieve different shaft drive was designed, the drive the disk cam-linkage combined mechanism different axis, mobile cam-linkage combined mechanism coaxial driver disk cam-linkage combined mechanism coaxial driver were designed too. A car need coaxial drive coupled with different shaft drive, preferably out of the front and rear axle drive the disk cam-linkage combined mechanism, different institutions shaft driven by a rack and pinion combination to achieve the two-axle steering through modeling and simulation analysis,and verify its trajectory in full compliance with the Ackerman steering principle.