1 Introduction With the development of electronic information technology, the world machine tool industry has entered the era of mechatronics with digital manufacturing technology as its core, among which CNC machine tools are one of the representative products. CNC machine tools are an important basis for the processing of the manufacturing machine and the national economy. It provides equipment and means for all sectors of the national economy, with unlimited economic and social effects.
Spindle is an important part of the composition of CNC machine tools. It plays an important role in improving processing efficiency, expanding the range of processing materials, and improving the quality of processing. The spindle drive system adopting the inverter structure can realize stepless speed regulation, and has the advantages of wide speed range, simple structure, cost saving, etc. It is very common to use on the machine tool.
Haipu Monte HD30 series inverter has achieved excellent results in the application of CNC machine tools with its superior performance and high reliability.
2 Technical requirements for the spindle drive of CNC machine tools The spindle drive of CNC machine tools is an important part of CNC machine tools. It has the following technical requirements for the drive system:
Acceleration and deceleration can be achieved quickly: Generally, the acceleration and deceleration time requirements of CNC machine tools are relatively short, generally about 1~2s, so the dynamic performance of the inverter is required to be higher.
The need for strong overloading at low speeds requires that the frequency converter has reliable overload protection.
It can provide enough torque output at low speed: According to the working characteristics of CNC machine tools, it is generally required that the spindle drive system can output 150% of the rated torque at 1~2Hz.
High accuracy of steady speed: For high-speed rotating spindle motors, excessive speed fluctuations will affect the machining quality of the workpiece. Therefore, the speed stability of the drive system is demanding.
Convenient interface: The general CNC machine tool control operation command comes from the terminal given, the frequency given instruction comes from the analog quantity, so the inverter has the matching terminal and the analog quantity interface.
3 Introduction of HD30 Vector Control Inverter The HD30 series vector control universal inverter is a new generation of vector control inverter developed by Shenzhen Haipu Montetech Co., Ltd. It has a low-speed torque capability, high control accuracy, and ultra-quiet operation control. Built-in process PID, programmable analog curve, 16-segment multi-speed operation, logic programmable input/output terminals, multi-frequency given channel design and other special features combine the common requirements with the individual needs of industry users, providing Highly integrated integrated solution. At the same time, it has a strong power grid and environmental adaptability, high reliability, and simple operation.
4 Features of HD30 Vector Inverter In accordance with the technical requirements of the spindle drive system of CNC machine tools, the HD30 series inverter has numerous targeted advantages:
1. With reliable overload protection, it can reliably output more than 150% of the rated output current for more than 2 minutes;
2. The starting torque can reach more than 180% at 0.5Hz, which meets the need of low speed and large torque for the spindle drive of the machine tool;
3. At least two standard analog input interfaces (AI1 voltage 0~10V, AI2 voltage/current selectable -10V~+10V/0~20mA DC) are compatible with most CNC system interfaces and have strong universality;
4. Using the latest algorithm, the analog input has high linearity and high accuracy;
5. The output terminal logic is programmable. Can output such as zero speed signal, running signal, speed arrival signal, fault indication, etc., to meet the system's monitoring of the spindle speed status;
6.55KW and below power level models all have built-in brake units, eliminating the need for external brake units.
7. The carrier frequency range of 1~16kHz effectively reduces the whistling sound of the spindle system.
8. Standard RS485 communication interface, MODBUS communication protocol, with dedicated PC debugging software;
9. Online identification of motor parameters to ensure system stability and accuracy;
10. Adaptive control of power grid voltage effectively avoids the interference caused by voltage fluctuations.
5 Application of HD30 Vector Control Converter on Machine Tool Spindle The applied machine tool system adopts Fanak CNC system. The debugging process and effects are as follows.
5.1 debugging process 1) wiring according to Figure 1;
2) Set the motor parameters according to the motor nameplate;
3) Disconnect the motor load, use the JOG function to determine the motor rotation direction, and change the wiring to positive rotation;
4) Carry out motor parameter self-tuning;
5) Set the maximum output frequency and upper limit frequency;
6) Set command given channel and frequency to channel;
7) Set the acceleration and deceleration time;
8) Set the analog function;
9) Set the terminal function;
10) Set the braking unit operating voltage;
11) Cancel overvoltage stall and automatic current limiting.
5.2 Final parameter setting function code number Description Setting value and description F00.06
Maximum output frequency 200.00Hz (Rated motor frequency 50.00)
F00.08
Upper limit frequency 200.00Hz
F00.10
Frequency reference channel 3 (analog given)
F00.11
Command given channel 1 (terminal command given)
F03.01
Acceleration time 1s (acceleration time is from zero frequency to maximum frequency)
F03.02
Deceleration time 1s (deceleration time is from maximum frequency to zero frequency)
F05.04
Line 1 maximum given corresponding value 100% (external 10V corresponding maximum output frequency)
F15.00
DI1 terminal function selection 2 (FWD function)
F15.01
DI2 terminal function selection 3 (REV function)
F15.02
DI3 terminal function selection 41 (terminal free stop normally open input)
F15.03
DI4 terminal function selection 46 (external reset RST input)
F16.01
Analog input AI1 function selection 2 (frequency setting channel)
F16.07
Analog input AI1 filter time 0.1 s (analog input AI1 filter time)
F19.18
Overvoltage stall function allows 0 (to prohibit overvoltage stall)
F19.20
Automatic current limit action selection 0 (automatic current limit function is disabled)
F19.24
Braking unit operating voltage 680V
5.3 Inverter wiring The following figure shows the wiring of the inverter:
figure 1
Among them, DI1, DI2, DI3, and DI4 are respectively set to FWD, REV, terminal free stop input, external fault reset command, and AI1 is used as the frequency reference channel. Programmable relays are often output as fault relays to the controller.
5.4 Debugging effect Under the conditions of no load (when no parts are machined), the deviation between the actual running speed and the set target speed does not exceed 1 RPM. When the machine tool processes parts (actual torque is equivalent to 80% of the motor rated torque), the cutting dynamic speed momentarily drops, and under the condition of vector control speed loop, the speed quickly recovers to the vicinity of the given rotation speed; the actual measurement speed deviation also does not exceed 1 RPM .
5.5 Commissioning Notes 1. Because the vector control's low frequency torque and steady speed accuracy are better than V/f control, it is better to use vector control when the machine tool spindle is driven.
2. Because the vector control process needs to accurately obtain the motor parameters, it is necessary to accurately input the motor nameplate value and perform motor parameter auto-tuning.
3. Because the general frequency command of the machine tool system is given by the analog quantity, and the following characteristic of the frequency instruction is very high, it is recommended to reduce the analog input filter time as much as possible to meet the requirements of the fast follow frequency instruction under the premise of satisfying the immunity. .
6 Conclusion HD30 vector control inverter has been successfully applied in the field of CNC machine tool drive control, its superior performance (large low-frequency torque, wide speed range, high steady-state accuracy, fast acceleration and deceleration, easy operation, full function protection) and High reliability has been fully verified and fully meets the spindle control of CNC machine tools.
references:
1. Shenzhen Hpmont Technology Co., Ltd. HD30 Series Vector Control Inverter User Manual.
About the Author:
Author: Qiu full Ning Baoji City Dragon Machinery Manufacturing Co., Ltd. Machine Tool Division managers, mid-level titles, the second author: Zhang Ning Shenzhen Sea Technology Co., Ltd. Pu Monte Research and Development Department engineer, intermediate titles in 2006 Harbin Institute of Technology Power Electronics power transmission and Master's degree in 2006 has been engaged in research and development drive of the third: Deputy Director Pu Monte sea Research and development Department Wang Guofeng technology Co., Ltd. Shenzhen, intermediate titles in 2000 Love power Electronics and power drives University of technology professional Graduate student graduated from 2000 to date engaged in research and development of frequency converter
