The Application of CHE Vector Frequency Converter in CNC Machine Tools
1 Introduction
The main drive system of CNC engraving machine tools mostly uses stepless speed change. At present, there are mainly two types of continuously variable transmission systems: frequency conversion spindle system and servo spindle system. DC or AC spindle motors are generally used. Drive the spindle through the belt drive, or drive the spindle through the belt drive and the reduction gear in the spindle box (for greater torque). Due to the wide speed range of the spindle motor and stepless speed regulation, the structure of the spindle box is greatly simplified. At present, due to the high performance-to-price ratio of the frequency converter, the frequency converter is very popular on the machine tool. Inventronic CHE series vector inverters are rapidly emerging in the application of CNC machine tools with their unique performance and superior cost performance.
CNC system shown in Figure 1:
2, the main performance requirements of the system
(1) Small speed fluctuations in the full speed range;
(2) Low torque at low speed can ensure low speed cutting;
(3) The time for acceleration and deceleration is as short as possible.
3, the main functional requirements of the system
(1) Control mode selection is V/F control;
(2) Terminal control is required as the command source. Two-wire terminal control: FWD is forward running (S1 input), REV is reverse running (S2 input);
(3) The frequency source is an analog setting (computer control board output 0 ~ 10VDC), only need to input frequency command from AI1 port;
(4) The running speed is generally 0～21000r/min, and the running frequency of the inverter is 0～350Hz (secondary high-speed motor);
(5)Acceleration and deceleration time according to the customer's own needs, generally in 3 ~ 5s, due to the higher speed of the operation, so need a frequency converter with a braking unit;
(6) Fault output signal (Y output) and fault reset signal (S3 input) are required.
4, system description
The inverter electrical wiring is shown in Figure 2.
The AI1/GND terminal of the inverter provides the analog quantity with the numerical control system speed, AI1 is connected with the positive analog signal of the numerical control system interface, GND is connected with the negative signal, the signal is the 0~10V analog voltage signal, and the spindle speed is controlled. S1/S2/COM is the forward/reverse signal terminal of the inverter. The forward or reverse signal is sent from the CNC system to drive the intermediate relay. The normally open contact of the intermediate relay is connected to the inverter S1/S2/COM. This controls the forward and reverse rotation of the inverter.
5, the main function parameters of the inverter
P0.00: 1V/F control;
P0.01: 1 terminal command channel;
P0.03:1 analog AI1 setting;
P0.04: 350HZ (maximum output frequency);
P0.05: 350HZ (operating frequency upper limit);
P0.08:5s acceleration time (set according to actual conditions);
P0.09:3s deceleration time (set according to actual conditions);
Group P2 is set according to motor nameplate parameters;
P4 group V/F control group is set according to the actual situation;
P5.00:1 forward operation;
P5.01: 2 reverse operation;
P5.02:7 fault reset;
P5.05:0 two-wire control 1;
P6.00: 3 fault output.