Research And Analysis Of A New Type Of 4-DOF Parallel Machine Tool Configuration

With the growing strength of our manufacturing powers and the growing manufacturing industry,CNC machine tools are used in various industries and fields and play an extremely important role.With the development of CNC machine tools,machine tools are roughly divided into three categories: tandem machine tools,parallel machine tools and hybrid machine tools.Among them,parallel machine tools have become the mainstream of machine tools due to their high stiffness-to-weight ratio,fast response speed,high machining accuracy and good mechanical flexibility.At the same time,parallel machine tools have become one of the necessary processing equipments for difficult-to-machine parts or special manufacturing fields due to their large working space,high flexibility and large processing range.Based on the advantages of parallel machine tools,this paper designs a new 4-DOF parallel machine tool with a new parallel mechanism as the mechanical configuration of the parallel machine tool.The main research contents are as follows:From the configuration assumption to the configuration description of the 4-DOF parallel machine tool,the parallel machine tool was modeled by the INVENTOR 3D modeling software,and the animation of its four degrees of freedom motion was simulated.Confirm the feasibility of the institution and give a schematic diagram of the mechanical structure of the organization.The degree of freedom is checked using the modified mechanism degree of freedom calculation formula.Kinematics analysis was performed on the 4-DOF parallel machine tool mechanism.Establish a relative static and dynamic coordinate system on the mechanism,obtain the rotation angle variation equation of the machine platform and the direction vector of the machine tool head relative to the moving platform coordinate system {B},and then inversely solve the inverse kinematics equation of the parallel mechanism.And the speed relationshipmatrix of each drive slider.Finally,the MATLAB software is used to simulate the numerical simulation of the movement displacement of each drive slider of the machine tool.The geometrical method is used to analyze the working space of the mechanism.In AutoCAD,the working area of each two-dimensional plane is obtained for the mechanism,and then the obtained two-dimensional working areas are superimposed by space to obtain the machine tool mechanism.3D workspace.Based on the search method,the MATLAB software is used to find the set of workspace boundary points of the mechanism under the geometrical dimensions of the model.Finally,based on a specific workpiece process,the mechanism calculates and calculates the necessary stroke length of the mechanism slider.The Jacobian matrix of the parallel mechanism is obtained by vector construction method and Jacobian matrix definition method respectively.The MATLAB software is used to simulate the Jacobian matrix condition of the machine tool.The range of C(J)value of the mechanism is obtained,which proves the dexterity performance of the parallel mechanism.The new four-free is verified by the Jacobian matrix of the mechanism.Parallel machine tools do not have singularities in their workspace.