上三角肘杆式压力机构间隙动力学特性分析

Analysis on dynamic characteristics of upper triangular toggle press mechanism clearance

压力机械的运动副常因受到反冲作用力而产生运动间隙,导致机械系统的冲击增大,冲压成形稳定性降低。优选三角肘杆式压力机构运动副间隙动力学的建模及仿真,依据其工作原理分析了上三角型与下三角型肘杆式压力机构执行连杆的运动特性变化规律,得出上三角型相对下三角型在位移、速度和加速度方面分别优化了30%、59%和390%;基于MLSD运动副间隙模型,运用ADMAS虚拟样机技术建立了含运动副间隙上三角型肘杆式压力机构的动力学仿真模型,分析了运动副间隙引起的碰撞和磨损对机构动态特性的影响。结果表明,运动副相对间隙值超20%时,机构运行将伴随较大的冲击,并伴随一定程度的振动和噪声,影响机构工作的稳定性。研究结果为肘杆式压力机构的结构设计提供了理论依据。

The moving pair of pressure machine is often prone to produce movement gaps due to the recoil force, which leads to the increase of impact for mechanical system and the decrease of stability for stamping forming. Therefore, the dynamic modeling and simulation of moving pair clearance for triangular toggle press mechanism were optimized. Based on its working principle, the variation rules of motion characteristics for the executive connecting rod of upper triangle type and lower triangle type toggle press mechanisms were analyzed, and the displacement, velocity and acceleration of the upper triangle type were optimized by 30%, 59% and 390%, respectively, compared with the lower triangle type. Then, based on moving pair clearance model MLSD, a dynamic simulation model of upper triangular type toggle press mechanism with moving pair clearance was established by virtual prototype technology ADMAS, and the influences of collision and wear caused by moving pair clearance on dynamic characteristics of the mechanism were analyzed. The results show that when the relative clearance value of moving pair exceeds 20%, the operation of the mechanism is accompanied by great impact, as well as vibration and noise to a certain extent, which affects the stability of the mechanism. Thus, the research results provide theoretical basis for the structural design of toggle press press mechanism.