Generally, the CNC roller bed uses the grid ruler as the feedback component in the longitudinal (Z) and transverse (X) directions for full closed-loop control. The FIDEC numerical control system requires high mechanical accuracy and grid ruler installation accuracy. The mechanical accuracy (rigidity, clearance, back clearance, etc.) of the CNC roller bed objectively exists. The random installation of the grating ruler often causes the failure of the FIDEC CNC system. It directly affects the normal working reliability of CNC lathe. The FIDEC numerical control system has many parameters and long debugging cycle.

In this paper, CNC roller machine is applicable to rough and finish machining of cast iron, steel and non-ferrous metal parts, and high-speed steel and cemented carbide tools are selected. This CNC lathe can complete cylindrical turning, end face turning, grooving and external surface turning. Taper or other special processing requirements can also be selected for new opening and repair of roller tables, and finishing and rough turning.

The numerical control system is FIDEC0i-TF, and the maximum diameter of the workpiece is cut φ 1600mm, the machining length of the cutting workpiece is 600 mm, and the mass is 40 t. Longitudinal sliding box α IF40/3000FIN servo motor drive. The longitudinal sliding box is a hydraulic automatic clearance double-knife sliding box. The horizontal carriage is driven by the ball screw and decelerated by the primary gear α IF40/3000FIN servo motor drive.

2. Analyze the reasons in depth.

Due to the length of the transmission chain of the longitudinal sliding box (see Figure 1), the effective measuring length of the longitudinal grating ruler is 6640mm, and there are many parts that directly affect the mechanical accuracy, such as the accuracy of gears and other components, bearings and shafts, installation accuracy, clearance, etc. The reason is that when the circuit is completely closed, there will sometimes be obvious vibration and various fault alarms in the longitudinal direction. In order to better analyze the cause and finally deal with the problem, the interferometer is selected to detect the mechanical installation accuracy, so that the mechanical installation accuracy can meet the accuracy requirements of the CNC rolling lathe, optimize the parameters of the CNC system, do a good job in the grounding of the CNC lathe, the panel of the CNC system, the power amplifier, and the separation detection unit, and eliminate the general interference problems. Use the instrument to detect HEIDENHAIN grating ruler to detect signals such as HEIDENHAIN grating ruler. After all the above works are qualified, mechanical vibration and alarm problems still cannot be solved. At this time, the machine is changed to semi-closed loop, and the machine can operate stably.