Commissioning of CNC machine tools

The debugging of CNC machine tools includes the inspection of the power supply, the confirmation and setting of the electrical parameters of the CNC system, the adjustment of the machine's geometric accuracy, etc. The inspection and debugging work is related to the normal use of the CNC machine tools.

      I. Inspection of power supply

       1. Confirmation of power input voltage, frequency and phase sequence. Check whether the input voltage of the power supply matches the setting of the machine tool and whether the frequency conversion switch is set to the corresponding position. Check whether the capacity of the transformer meets the power consumption of the control unit and servo system. Check whether the power supply voltage fluctuation range is within the range allowed by the CNC system. Japan's numerical control system generally allows fluctuations within the range of ± 10% of the voltage rating, while European and American numerical control systems require higher, within ± 5%, otherwise an AC voltage regulator is required.

        For the power supply of the speed control unit and spindle control unit using thyristor control elements, the phase sequence must be checked. When the phase sequence is incorrect, turning on the power may blow the input fuse of the speed control unit. This is caused by the large current caused by misconduction.

        There are two methods of phase sequence check: one is measured with a phase sequence table, and when the phase sequence connection is correct (that is, the phase sequence with the terminal marks on the table is the same), the phase sequence table is rotated clockwise; the other is You can use an oscilloscope to measure the waveform between the two phases. Take a look at the two phases to determine the phase sequence.

        2. Check whether the DC power supply unit voltage input terminal is short-circuited to ground. There are DC stabilized power supply units in various CNC systems to provide the system with + 5V, ± 15V, + 24V and other DC voltages. Therefore, before the system is powered on, the load of these power supplies should be checked with a multimeter for short circuits to ground.

        3. Check whether the voltage on each printed circuit board is normal. After turning on the power, you should first check whether the fans in the CNC cabinet are rotating, confirm whether the power is on, and whether the various DC voltages fluctuate within the allowed range. Generally speaking, the voltage requirement of + 5V power supply is higher, and the fluctuation range is within ± 5%, because it is supplied to the logic circuit; + 24V power supply should be within ± 10% fluctuation range. Adjust, otherwise it will affect the stability of the system.

      2. Confirmation of parameter setting

        1. Setting of short bar

         There are many short-circuit bars on the printed circuit board in the numerical control system to set the short-circuit. This setting has been completed by the machine tool manufacturer. The user only needs to confirm and record it. However, for a single purchased CNC device, the user must set it according to his needs. Because the numerical control device is set in a standard way when it leaves the factory, it may not be suitable for specific user requirements. The content of setting confirmation depends on the CNC system, and has the following three aspects.

        (1) Confirm the settings on the printed circuit board of the control section

        (2) Confirm the settings on the printed circuit board of the speed control unit

        (3) Confirm the settings on the printed circuit board of the spindle control unit

         2. Confirm the setting of various parameters in the CNC system

      Three. Machine tool test run

      Test of machine tool accuracy and function

      V. Trial operation