Analysis Of Spatial Dynamic Characteristics Of Cradle-type Five-axis CNC Machine

In recent years,with the continuous improvement of the research and development accuracy of my country's machining centers,the impact of the dynamic characteristics of high-speed and high-precision machine tools on the processing quality has been unable to be ignored.During the machining process,in the working space of the machining center,the posture of the tool will change with the machining process.During this process,the stiffness chain of the machine tool will also change,so that the stiffness matrix changes,which in turn affects the dynamic characteristics of the machining space.This article is mainly aimed at the impact of changes in the dynamic characteristics and vibration of the cradle-type machining center on machining accuracy during machining.At the same time,considering the influence of the joint surface parameters on the dynamic characteristics of the whole machine,the dynamic characteristics parameters of the machine tools at typical machining positions are analyzed,and the dynamic characteristics values ??are fitted with Kirging model to obtain the dynamic characteristic spectrum of the machining center,and the processing s Tab.area is discussed Provide theoretical support for the selection of a reasonable working space for subsequent processing.The main research contents of this article are as follows:First,establish the dynamic model of the cradle-type machining center joint surface(fixed joint surface and movable joint surface),and use the Hertz contact theory as the core solution method to obtain the axial contact stiffness of the ball screw pair and the linear roller guide The value of the normal stiffness provides a basis for subsequent finite element analysis.The 3D model of the cradle machining center is established in the UG NX 3D software,which is imported into ANSYS for finite element analysis of the machiningcenter to obtain the dynamic characteristics of the machine.The modal parameters of the tool spindle of the cradle machining center at the machining origin were extracted by modal hammering method,and compared with the finite element results,the validity of the finite element model was finally verified.The modal parameters of the tool spindle of the cradle machining center at the machining origin are extracted by the modal hammering method,and compared with the results of the finite element to finally verify the validity of the finite element model.Discrete the working space of the VMC-C50 cradle machining center with the spindle feed and Tab.pose of the cradle machining center as parameters,and perform modal simulation on typical working poses,and establish Kirging based on spatial statistics The prediction model is used to obtain the dynamic characteristic spectrum of the tool holder in the working state,and the law of the vibration characteristic spectrum is analyzed and summarized,so as to provide theoretical support for the subsequent search of the processing s Tab.region.