Into The Analysis Of The Dynamic Characteristics Of The System Beam Type CNC Machine Tools

As the final mechanical executing components of CNC machine tool, the feed system directly affects the machining quality of mechanical products. Beam-type feed system is an essential feed system of gantry type machine tool, so it is necessary to carry out a systematic study.The structural and mechanical feature of beam-type feed system is studied, and the force analysis to the main components of system is carried out. Based on the computational formulas, MATLAB software is used to curve plotting. The results show that the stress of sliders decreases as the rail span increases or the vertical height of worktable relative to screw axis reduces. According to the structural feature of system, remote loading method is proposed to simply the model of system, which is not only facilitate the calculation, but also the simplify modal is reasonable, and the maximum difference of calculated modal frequencies is2.08Hz.The disciplines of single and double screw, screw mounting position, guide rail span, screw span and beam structure how to affect the dynamic characteristics of beam-type feed system are studied. It turns out that the double-screw anti-torsion moment ability is18.9%stronger than single-screw, that the beam-type feed system has the best static and dynamic characteristics when the single-screw mounting on the cross slide mass center, that the anti-overturning moment ability is improved33.9%by increasing guide rail span from375.5mm to735.5mm, that the anti-torsion moment ability is improved25%by increasing screw span from567mm to1067mm, that the O-shaped is the best ribbed plate shape on O-shaped,’*-shaped’,’#-shaped’ and ’W-shaped’, and that the beam has the best static and dynamic characteristics when the height to width of the ’O’ closes to1, which makes the beam dynamic performance reach optimal state when the beam in a certain thickness range.SGM50A beam feed system is used as an example for verification research. Freedom modal test and finite element analysis is conduct to vertical slide plate of the feed system, the error between0.7%to8.9%, which proves that the simplify model of vertical slide plate is reasonable. Remote loading method is used to modeling the feed system, then the modal test and finite element analysis is carry out, the error between0.7%to4.4%, which indicate that the finite element model of beam-type feed system is correct.