面向数控机床可靠性试验的多维力随动加载装置

Multi-axis Loading Device for Reliability Tests of CNC Machine Tools

面向五轴联动数控机床的可靠性试验提出多维力随动加载方法,对五轴联动进给主轴施加多维力载荷,形成复杂进给抗力,部分模拟主轴复杂切削力环境。基于6-PUS并联机构研制多维力随动加载装置,采用模糊PID控制器建立显式力控制系统,比例和积分增益可随加载误差自适应调节。在五轴联动数控机床上开展多维力随动加载实验,结果表明,加载装置能够跟随机床主轴的单轴、三轴联动和五轴联动进给运动,根据期望值对主轴施加三维力,加载误差小于3.2%,在机床执行多种加工轨迹时形成有效进给抗力,为后续引入动态加载模拟复杂切削力提供理论和装备支撑。研究成果可为数控机床可靠性试验提供低成本、可循环的加载方式,有利于测试的规模化和标准化发展,也可为精度保持性、超载试验、跑合试验等机床性能测试提供新的负载模拟思路。

A multi-axis loading device with load-while-track capacity was proposed to generate multi-axis feeding resistance for the reliability test of CNC machine tools.This provided the research foundation to simulate complex cutting forces in real machining processes.The loading device was developed by a 6-PUS parallel mechanism.Based on a fuzzy PID controller,an explicit force control system was established,which could adaptively adjust the proportional and integral gains according to loading errors.Multi-axis loading experiments were conducted on a real five-axis CNC machine tool.Results show that the loading device may track the uniaxial,three-axis and five-axis feeding motion of the spindle and simultaneously apply three-axis forces to the spindle;the maximum loading error is less than 3.2%.This illustrates that the device may effectively generate multi-axis feeding resistance to the spindle that is performing various feeding trajectories.Research fruits may supply the theoretical support and equipment to the future work on simulating cutting forces by dynamic loading.The loading device provides a new loading method for the reliability test of machine tools,and assists large-scale development and standardization of the test.Besides the reliability test,the loading device may also be utilized in other performance evaluations of machine tools,such as accuracy retainability,overload,and run-in test.