【摘要】 以常发CF700型拖拉机为研究对象,对拖拉机前桥油气悬架进行了研究。建立前桥悬架拖拉机3自由度振动模型,运用MATLAB/SIMULINK仿真研究前桥悬架参数对拖拉机振动特性的影响,综合考虑选取前桥悬架刚度系数120~160 k N/m,阻尼系数8~10 k N·s/m。根据拖拉机前桥悬架的参数要求,设计了刚度和阻尼均可调的油气弹簧悬架系统。建立了1/4拖拉机振动模型,模拟拖拉机前桥悬架的实际工况载荷,对自行设计的油气弹簧进行了1/4车体试验,试验研究了悬架位移传递率及簧上质量的振动加速度响应特性。试验结果表明:位移传递率随激振频率的增高而减小,并没有出现共振的现象,整个振动过程呈现过阻尼的状态;振动加速度均方根值随激振频率的增高而增大,而簧上质量的响应振动加速度都明显小于激振台的振动加速度,轮胎动载荷响应随着正弦激振频率的增大而逐渐增加。所设计的油气弹簧有效地抑制了振动,能够提高拖拉机的行驶平顺性和乘坐舒适性。该研究为后期开发前桥悬架半主动油气弹簧系统提供了重要的理论依据。更多还原

【Abstract】 The CF700 tractor was taken as the research object, tractor front axle hydro-pneumatic suspension was studied.The 3 DOF vibration model of front axle suspension tractor was built up with the MATLAB/SIMULINK, the influence of front axle suspension parameters to the vibration characteristics of tractor was researched. Choose the stiffness coefficient of front axle suspension is 120~160 k N/m and the damping coefficient is 8~10 k N·s/m. Based on the requirement of CF700 front axle suspension parameter, hydro-pneumatic spring system with controllable stiffness and damping was designed. A quarter of tractor vibration model is established by simulating the actual working load of the tractor front axle suspension. A quarter vehicle tests have been carried out for the designed hydro-pneumatic spring, and the suspension displacement transmissibility and the sprung mass vibration acceleration response were researched by experiment. Results show that the displacement transmissibility decreases with the increasing of the excitation frequency, and the phenomenon of resonance did not appear, the whole process is a state of damping vibration. Vibration acceleration root mean square increases with the vibration frequency increases, and the response of the sprung mass vibration acceleration are significantly less than the vibration acceleration of actuating vibration table. Dynamic load response of the tire increases with the increase of sinusoidal vibration frequency gradually. The designed hydro-pneumatic spring effectively suppress the vibration, it can improve the ride comfort and performance of the tractor. The research provides important basis for the later development of the semi-active hydro-pneumatic spring system of tractor front axle suspension.更多还原