Research On Static And Dynamic Characteristics Of Static Pressure Tool Holder With Constant Pressure Oil Supply

With the vigorous development of modern manufacturing technology,large machine tools are developing towards high precision and high automation.Among many kinds of large-scale machine tools,vertical lathe is more suitable for processing disk-shaped parts and engineering parts with small length-diameter ratio because of its own structural characteristics.Moreover,with the innovative development of vertical lathe,its cutting stability is gradually improved,and it has become an indispensable processing equipment in the development of China’s machinery industry.Hydro-static bearing technology has been widely used in CNC machine tools because of its strong bearing capacity and reliable lubrication performance.With the application of hydro-static guideway technology in CNC vertical lathe becoming more and more extensive,the requirements for the cutting performance of the vertical lathe tool holder installed with hydro-static guideway become higher and higher.Therefore,it is of great significance to explore the static and dynamic characteristics of the hydro-static tool holder for improving the machining accuracy of the vertical hydro-static lathe.In this paper,the researcher takes the hydro-static tool holder of the vertical lathe with constant pressure oil supply as the research object,combines theoretical mechanics,fluid mechanics and other relevant knowledge in mathematical modeling,explores the static and dynamic characteristics of the hydro-static tool holder through ANSYS finite element simulation software,and measures the deformation and the natural frequency of the tool holders.The main research contents are as follows:Firstly,the working principle of the static press tool holder is expounded,and the force of the ram is analyzed.Under the condition of a certain oil supply pressure,the static characteristics of the static press tool holder are analyzed theoretically.Secondly,the ANSYS Fluent fluid simulation software was used to compare and analyze the pressure of the rectangular and racetrack oil film.The Workbench fluid-structure coupling simulation software was used to simulate the deformation of the static press tool holder of the rectangular oil chamber and the racetrack oil chamber respectively,and the shape and state of the oil film under different engineering conditions were obtained.The modal analysis and harmonic response analysis of the hydro-static tool holder are carried out through the Workbench to determine the natural frequency,vibration mode and resonance frequency of each order of the hydro-static tool holder.At last,the experiment was carried out on DVT630×40/100Q-NC,a hydro-static vertical lathe with constant pressure and oil supply,the deformation of ram of hydro-static tool holder and the natural frequency of tool holder were measured,and the experimental values were compared with the simulation values to verify the accuracy of the simulation results.