Study On Static And Dynamic Characteristics Of Hydrostatic Guide Of Ultra-precision Grinding Machine

Lasers have broad application prospects and the laser crystals that generate lasers are difficult to process,which have high requirements on the performance of machine tools.At the same time,high-level ultra-precision machine tools are an indispensable support for today's cutting-edge technology.China still has a long way to go from the world's advanced level in this field.The development of ultra-precision technology is of great significance.As a part of the machine tool,the rail system has a great impact on the quality of the machine tool.Based on the characteristics of the world's advanced ultra-precision machine tools,this paper designed a hydrostatic guide rail according to the project requirements.Determined its structural form and parameters and then obtained the bearing capacity and stiffness characteristics of the oil chamber theoretically.The relationship between static characteristics and the design parameters were studied.Proposed a method that makes the initial stiffness of the oil chamber close to the maximum stiffness in the work.On the basis of static analysis,the dynamic model of the oil film was established and the characteristics of the stable transition process and dynamic stiffness of the guide rail were obtained by simulation.The fluid simulation of the oil area of the single oil cavity was carried out by means of the simulation software.The pressure and velocity distribution of the oil area were studied.The error of the results between the simulation and the theory was analyzed and verified by parameter modification.Based on this,the coupling simulation of the rail system was carried out,and the deformation of the slider under the action of oil pressure was obtained.The influence of this deformation on the straightness of the guide rail was analyzed.By using the spring to connect the simulated rail joint surface and taking into account the effect of oil pressure,the pre-stressed modal simulation and harmonic response analysis of the slider were carried out.The first six modal parameters of the slider and the vibration of the upper plane under different frequency loads were obtained.Finally,related experiments were carried out on the processed guide rails.The stiffness and dynamic response of the guide rails were measured by the loading device and the displacement sensor.The experimental results were in good agreement with the theoretical analysis and reasonable explanations were given for the experimental error.The straightness of the guide rail was measured by photoelectric self-collimator,which separated the installation and manufacturing error of the slider and obtained the relationship between the oil supply pressure and the straightness of the guide rail.The modal of the slider was identified by the dynamic signal test and analysis device and the first six modal parameters were obtained.The actual modal frequencies were close to the simulation result.It indicated that the simulation studies were in good agreement with the actual situation.which had certain value for identifying the characteristics of the guide rail and guiding the machining work.