非线性拉削力对键槽拉床液压系统输出特性的影响研究

Influence to performance of keyway broaching hydraulic system caused by dynamic broaching force

针对拉削过程中动态拉削负载对液压系统输出特性的繁杂影响问题,对卧式键槽拉削系统进行了研究。首先,基于非线性拉削负载模型和拉削主油缸动力学模型,提出了拉削过程中的耦合动力学模型;然后,分别利用理论计算及系统实验,对拉床液压系统在非线性负载扰动下的实际输出力波形进行了研究。实验分析结果表明:动态拉削力的非线性特征主要由参与切削的齿数波动造成;拉削液压系统的输出非线性特性主要由动态拉削力影响主油缸容腔压力变化率和活塞运动特性造成;实际拉削系统设计必须增大液压系统的相对刚度,以降低动态拉削力所引起的液压系统波动。

Facing the complicated influence of dynamic broaching force on the output performance of hydraulic system,a keyway broaching system was researched. Firstly,based on the nonlinear broaching load model and the dynamics of main cylinder in broaching,coupled dynamics of broaching process was provided. Then,the output waveforms of hydraulic system on broaching under nonlinear disturbance were analyzed by the numerical simulations and experiments. The results indicated that the nonlinear characteristic of dynamic broaching force is mainly caused by the variation cutting tooth numbers. And the nonlinear dynamics of the hydraulic system come from the volume variation rate of main hydraulic cylinder and rod motion infected by the dynamic broaching force. Therefore,it is necessary for suppressing the vibration of hydraulic system caused by dynamic broaching force in broaching machine design to increase the relative stiffness of the hydraulic system.