Application of Sunwoele VFD (Variable-frequency Drive) on CNC machine tools in Shenyang Machine Tool Factory

Application of Sunwoele VFD (Variable-frequency Drive) in CNC machine tools

I. Introduction

Numerical control machine tools, referred to as CNC machine tools (NC, Numerical Control), are electromechanical products that have been comprehensively applied over the past thirty years to integrate mechanical, electrical, hydraulic, pneumatic, microelectronics and information technologies. In modern machine tool production , generally using multi-motor drag, the spindle and each feed system are driven by their own motors. Due to the wide range of machine tool processing, different workpieces, different processes, and the use of different tools, the machine tool execution components are required to have different movement speeds. Therefore, the main motion of the machine tool should be capable of stepless speed regulation. The spindle speed regulation system generally uses an AC spindle. system.

With the development of frequency conversion speed regulation technology, the AC dragging of the spindle of CNC machine tools can also meet the needs well. The main drive motor drives the spindle to rotate through a belt drive, or drives the spindle to rotate through a belt drive and a reduction gear in the spindle box (to obtain greater torque). Since the spindle motor has a wide speed adjustment range and can be steplessly adjusted, the structure of the spindle box is greatly simplified.

2. Technical requirements for CNC machine tools

1. Requirements for motors

It is usually required to use a variable frequency motor, or an ordinary motor plus a fan to meet the motor's heat dissipation requirements at low frequencies, and the motor is required to have a wide speed range.

2 Technical requirements for VFD (Variable-frequency Drive)

a requires large low-frequency torque

150% rated torque can be produced at low frequency (1~10Hz).

b. Fast dynamic response of torque and high speed stabilization accuracy.

It can achieve good dynamic response effect. According to the change of load, it can respond quickly through the change of output torque, thereby achieving the stability of the shaft speed.

c. Slow down and stop quickly.

Generally, the acceleration and deceleration time of CNC machine tools is relatively short. The acceleration time is guaranteed by the performance of VFD (Variable-frequency Drive), and the deceleration time depends on an external braking resistor or braking unit.

d High reliability

VFD (Variable-frequency Drive) has low failure rate and stable and reliable operation

e Electromagnetic compatibility issues

CNC machine tools are in an industrial application environment, which not only requires the VFD (Variable-frequency Drive) to have strong anti-interference capabilities, but also cannot interfere with peripheral control equipment.

It can be seen from the working principle of VFD (Variable-frequency Drive) that the output of VFD (Variable-frequency Drive) contains certain harmonic components. If not handled properly during use, it will cause interference to other equipment. It is the equipment most susceptible to interference on CNC machine tools. It's a CNC controller. Once the CNC controller is interfered with, the system will not work properly. In particular, the frequency command and operation command of the VFD (Variable-frequency Drive) may also be interfered with. Severe interference may cause instability of the frequency command, malfunction of the VFD (Variable-frequency Drive), etc. The way to solve this kind of problem is to use VFD (Variable-frequency Drive) products that have passed the EMC test and passed strict EMC testing before leaving the factory.

3. System composition

1 CNC numerical control system consists of the following figure:

2 Configuration:

VFD (Variable-frequency Drive): HSF600-37R5GB

Braking resistor: 80Ω/750W

7.5KW speed regulating motor

4. Wiring and VFD (Variable-frequency Drive) system settings

1 VFD (Variable-frequency Drive) wiring schematic diagram

2. VFD (Variable-frequency Drive) parameter setting:

P0.01 =2 Terminal AI1 is analog input

P0.04=1 external terminal control

P0.07=150 (maximum output frequency)

P3.03=14 (external fault shutdown)

P3.17=2 (speed reached)

P3.14=19 (fault output)

P2.06=6 (carrier frequency)

P9.00=100 (slip frequency compensation gain)

P3.01=1 (X1 forward rotation)

P3.02=2 (X2 reversed)

P3.04=6 (X4 reset)

5. Characteristics of HSF600 series VFD (Variable-frequency Drive)

HSF600 series VFD (Variable-frequency Drive). It has low-rate output torque, high speed accuracy, reasonable price, complete functions, stable and reliable quality, and is an ideal choice for machine tool equipment. HSF600 series VFD (Variable-frequency Drive) has the following characteristics

1. Special CPU for motor control, space vector PWM control, ultra-quiet and stable operation.

2. Low frequency torque characteristics