Based On The Research Of Assembly Precision Of Heavy Gantry Machine Tools And Positional Accuracy Of Beam Space

Heavy machine tool manufacturing industry has become the core of each country manufacturing,due to the guide rail of the machine is too long,the weight is too large,plus the weight of beam and the influence of bolt pre-tightening force,thus the parallelism degree of double guide rail and dual drive synchronization cannot be guaranteed,so the assembly precision of the machine tool and the position accuracy of the beam space are difficult to determine.Therefore,it is of great significance to use the precision of the assembly and the precision of the location of the beam as the main line.Based on fractal theory and deflection theory,this paper takes bolt pretension force,beam self-weight,guide rail parallelism and dual drive synchronization as the research object,established the theoretical model between the influence factors-column joint assembly accuracy-beam space position accuracy,has carried on the simulation analysis and experimental verification,and finally achieve the following creative achievements:(1)Based on the fractal theory,the fractal parameters is established under the condition of microstructure,to study the influence of the assembly under the normal load(bolt pretension and beam self-weight),the tangential load(hydraulic cylinder thrust),the surface roughness,and the material.(2)Based on theoretical mechanics,mechanics of materials,the theory of flexural deformation,the theoretical models between the bolt pre tightening force,the crossbeam weight,the synchronization of thrust,the parallelism of rail and assembly accuracy of the joint surface,location accuracy of crossbeam are established respectively(the assembly precision is represented by the surface stress and the deflection of the column,the position precision of the beam is represented by the deformation of the beam),the influence of bolt pretension force,beam self-weight,hydraulic cylinder thrust synchronization degree and guide rail parallelism on the assembly stress and beam space position is discussed,and the simulation analysis is carried out.(3)A test platform for heavy-duty Longmen machine tool was built,the test of the joint surface stress and the position of the beam space is carried out by means of bolt pretension,beam self-weight,guide rail parallel degree and dual drive synchronization degree,verify the validity of the above theory and the simulation at last.This paper established the theoretical model,then through the simulation analysis and test,the influence of each influencing factor on the accuracy of the assembly and the position accuracy of the beam space is studied,research contents and conclusions have theoretical significance and practical value.