The Research On Coupling Compensation Of The Ram Flexure Deformation For TH6920

As a key component,the ram of the TH6920 large CNC floor type boring and milling machine has a great influence on the machining performance of the machine.It generates flexural deformation because of its weight and inclination of spindle box and weight of enclosures and assembly clearance,and it destroys the machining precision of the parts and the geometric precision of the machine tool,reduces the service life.So it restricts the wider application of the machining center.In order to solve this problem,a coupling compensation system consisting of "hydraulic cylinder-bars" and“tilting mechanism of spindle box" and "ram guide" is applied.A combined method of finite element analysis,numerical calculation and experimental technique is proposed.It achieves deformation analysis and coupling compensation,whose compensation result compensation meets the national requirements.It analyzes the deformation of the ram in theory.The movement of the machining center and the stress form of the ram are analyzed in detail.And it specifically analyzed and calculated the deformation parameters.It calculated the deformation values respectively caused by pressure of the principal axis,cutting force and weight of the ram,caused by tilting of spindle box,and caused by assembly clearance.Lastly,the theoretical calculation formula of the total deformation value of the ram is obtained by subsequent calculation and superposition principle.Simulate the flexure deformation of ram.The ram model is established and simplified in finite element software.Sampling analysis is used to simulate the deformation of the ram,and the maximum deformation value is 337.82?m.The simulation results are fitted by numerical simulation,and the curve fitting of the relationship between the stroke and the deflection is obtained.Achieve experimental verification of the flexure deformation of ram.It expounds the compensation principle of the coupling compensation device,analyzes the compensation effect of the different devices on the deflection of the ram,and explains the working process of the compensation device.The bending deformation of the ram is compensated and tested.The maximum values of the deformation of ram and spindle box at the stroke of 1200mm are respectively 346.5?m and 10.5?m,and the maximum deformation value after coupling compensation is 7?m,which meets the national requirements.It carries out the strength verification of the compensation device,and both of them are in a security scope.At last,achieve dynamic characteristic analysis of the ram.It carries out modal simulation analysis and harmonic response analysis for the ram model through Workbench ANSYS.The first six order dynamic characteristics and the result of harmonic response of the schedule 500 mm and 1000 mm are obtained,and it reasonably shows the effectiveness of ram structure.