摘要
针对伺服压力机肘杆机构运转中因旋转副间隙引发的周期性冲击问题,建立非线性时变六连杆系统动力学模型,系统研究间隙大小、驱动转速对系统动态特性及可靠性的影响规律,并揭示六连杆运动副间隙由于运动副元素分离导致的振动冲击机制。基于Lankarani-Nikravesh接触模型,得到运动副间隙碰撞力,并结合第一类拉格朗日方程构建含间隙的六连杆压力机动力学控制方程组。对该模型的变步长Runge-Kutta法积分迭代求解结果表明:运动副间隙大小对接触力波动较为敏感,其冲击力幅值随关节间隙和驱动转速增大而大幅增加,尤其是当旋转副间隙值超过0.5 mm、驱动转速大于90 r/min时,引起较大冲击力(峰值大于6 kN),同时冲击波动力大于120 kN,系统稳定性急剧恶化,导致机构运行可靠性明显降低。研究结果表明,较小的运动副间隙及合理的驱动转速对消除压力机冲击振动起到关键作用。
Addressing the periodical impact problem caused by the clearance between rotating pairs in the operation of a servo press,a nonlinear time-varying six-bar linkage system dynamic model was established to systematically study the influence of clearance magnitude and driving speed on the dynamic characteristics and system reliability.The vibration impact mechanism caused by the separation of motion pair elements in the clearance joint of the six-bar mechanism was also revealed.Based on Lankarani-Nikravesh contact model,the collision force between the moving pairs was obtained,and combined with the first-kind Lagrange equation,a set of dynamic control equations for a six-bar press with clearance was constructed.The results of a variable-step Runge-Kutta method integration solution for this model show that the magnitude of clearance between moving pairs is relatively sensitive to contact force fluctuations,and the impact force amplitude increases significantly with increasing joint clearance and driving speed.In particular,when the rotational clearance exceeds 0.5 mm and the driving speed exceeds 90 r/min,significant impact forces(peak values exceeding 6 kN)are generated,accompanied by shock wave force exceeding 120 kN.This leads to a significant degradation in system stability and a noticeable reduction in the reliability of the mechanism′s operation.The research results indicate that smaller motion clearance and reasonable driving speed play key roles in eliminating impact vibration in presses.
作者
孙万
王兆坤
汪子康
袁浩
江秀花
张忠强
SUN Wan;WANG Zhaokun;WANG Zikang;YUAN Hao;JIANG Xiuhua;ZHANG Zhongqiang(School of Mechanical Engineering,Jiangsu University,Zhenjiang Jiangsu 212013,China;Jiangsu CPTEK Servo Technology Co.,Ltd.,Changzhou Jiangsu 213000,China)
出处
《机床与液压》
北大核心
2025年第13期77-83,共7页
Machine Tool & Hydraulics
基金
企、事业单位委托项目(HX20230149)。
