The Technology And Realize Of Geometric Error Compensation For The TH6926B Floor Boring And Milling Machine Center

CNC floor boring and milling machine center is a heavy machine tool with extensive usages,which makes precise plane milling and boring processing for large parts.It is the key equipment requested by national key industries,such as energy,military,shipping,electric power,transportation,nuclear industry and heavy machine etc.This paper takes improving the accuracy of machine tool of TH6926B CNC floor boring and milling machine center in technology development process,studies the geometric accuracy problem of boring axis and ram of main parts,proposes specific error compensation methods and passes related experimental demonstrations.This paper mainly accomplishes the following:For the errors happened to drooping ram head caused by spindle box tilting aroused by deflection and ram movement of ram and boring axis,three hoisting point hydraulic balance compensation scheme has been designed and mathematical model of ram position coordinates and oil compensation pressure has been set up.then compensation for the drooping error produced by ram movement has been made.For the deflection error of boring shaft movement caused by gravity effect,program of mobile boring axis making corresponding compensation for Y axis(movement of spindle box)has been proposed.compensation for deflection of boring axis has been realized through the linear compensation function of numerical control system.For the thermal deformation produced to ram and boring axis,the main reason for temperature rise is high speed rotation of milling spindle.Mathematical model of temperature rise for the error of boring axis and thermal elongation of ram has been attained through making measurement and analysis of thermal deformation data of ram and boring axis.temperature compensation program has been designed on this basis and compensation for thermal elongation has been realized through the external origin offset function of numerical control system.This paper has made compensations for TH6926B through above compensation methods,which can reduce the defection error,drooping error and thermal elongation error of ram and boring axis,effectively and finally realize the geometric precision of machine tool and meet the processing demands of clients.