2. Process requirements:
Grinding machine is a machine tool that uses grinding tools to grind the workpiece surface. Most grinding machines use high-speed rotating grinding wheels to grind the workpiece. The high-speed rotating spindle is controlled by frequency converter, with the following requirements:
a. For low-frequency machining, the torque is large. During rough machining of the grinder, the main shaft needs to run at low-speed frequency. When the general frequency converter runs at low-frequency, the torque is small, which makes it impossible to process, so the frequency converter needs to have the characteristics of low-frequency and large torque
b. The spindle runs stepless speed regulation. The spindle adjusts different running speeds according to the requirements of the workpiece, so the frequency converter is required to have stepless speed regulation capability
c. High accuracy of operating speed. The high-speed rotation accuracy of spindle directly affects the accuracy of grinding workpiece, so the drive frequency converter must have high speed accuracy
d. The protection level is high. The grinding machine processing environment is in the environment of high oil pollution, high dust and high tide humidity. The frequency converter needs to have high protection level, otherwise it will cause short-circuit damage or even machine explosion.
e. The motor has low jitter and noise.
3. System scheme:
a. Scheme selection
According to the process requirements of the grinder, we choose qd800 series closed-loop vector converter with high protection level. The power of the converter matches the power of the driven motor.
b. Introduction to frequency converter
Qd800 series is a high protection grade closed-loop vector converter specially developed based on new software and hardware platform. It has the characteristics of superior performance, compact structure, complete protection functions, rich and flexible peripheral interfaces and functions, and can adapt to various harsh environments such as humidity and dust, It can flexibly carry out secondary development for all industrial applications and according to the site conditions. It has the following characteristics:
? High low frequency torque. The zero speed of closed-loop vector can reach 200% of the starting torque, and the zero speed of open-loop vector can reach 180% of the starting torque
? In high frequency operation mode, the maximum fundamental frequency output is 1000.0hz
? Built in a variety of system macros and application macros, which can simplify parameter setting through macro parameter call
? The priority of frequency / speed setting channel can be configured flexibly
? Rich warning and protection functions
? With high protection grade IP54, it can be used in various harsh environments such as humidity and dust
4. System advantages:
Using qd800 series closed-loop vector converter with high protection grade has the following advantages:
a. Large low-frequency torque, 0.3hz 200% starting torque in open-loop vector mode to ensure the normal processing of the system under low-frequency conditions
b. High speed stability accuracy. In the open-loop vector mode, the speed accuracy is 0.2%, ensuring the machining accuracy
C. the speed regulation range is wide, and the speed regulation range of 1:200 is enough to ensure stepless speed regulation
d. High frequency output, j600 up to 1000Hz frequency output to ensure the requirements of high-speed machining
e. The protection grade of IP54 can ensure the normal operation of the machine in harsh environment
5. Conclusion
Based on the new hardware design platform, qd800 series high protection grade closed-loop vector frequency converter can adapt to various harsh environments such as humidity and dust, effectively resist the damage to the frequency converter caused by dust, oil stain, high humidity, acidic corrosive substances and other high pollutants, ensure the safe use of the frequency converter in extremely harsh environments, and well solve the requirements of grinder use, It improves the efficiency, greatly reduces the failure rate caused by harsh environment, and is highly recognized by grinder customers.