Application of Frequency Converter in Control System of Main Spindle of Lathe
Abstract
Lathes are the basic production machines in mechanical processing. The accuracy and efficiency of parts processing depend mainly on the spindle of the lathe, which is driven by a motor. In order to meet the requirements of different machining processes, the speed of the lathe spindle needs to be changed. If the traditional mechanical speed change device is used, it will bring inconvenience to machining operation and reduce production efficiency. The application of frequency converter can solve this problem. This paper mainly explains the application of frequency converter in controlling the spindle speed of lathe, and its advantages in improving production efficiency and product quality are analyzed in detail.
1 Introduction
Lathe is the basic and common production machine in the machining process, which is mainly composed of lathe bed, headstock, tailstock, tool post and other components. The spindle of the lathe is the key component of the machine to realize the rotary cutting of the workpiece and realize the necessary deformation to obtain the desired geometric shape and machining accuracy. The spindle drive mode is mainly driven by motor. The speed of the motor is constant, and the mechanical transmission or electrical transmission is used to change the rotation speed of the spindle according to the requirements of the machining technology, so as to adapt to different processes and achieve better processing effect. Frequency converter is a new type of speed regulating device, which can achieve stepless speed regulation by controlling the input voltage and frequency of the motor through power electronics, so as to achieve the purpose of speed regulation.
2 Lathe spindle speed control system
The spindle speed regulation system of the lathe mainly includes the following components:
(1) AC motor, including asynchronous motor and synchronous motor.
(2) Frequency converter, including power part, control part and feedback part.
(3) V-belts, synchronous belts and couplings, etc., as transmission parts.
(4) Electrical components, such as contactors, coils, push buttons and indicators, etc.
3 The application of frequency converter in lathe spindle control system
3.1 Analog spindle speed control system
The traditional analog spindle speed control system of lathe is mainly composed of motor, power transformer, contactor, protection switch, electromagnetic speed regulating valve, speed measuring device and relevant instruments, and its spindle speed control range is limited. According to the control characteristics and operating conditions, the speed regulation system of lathe can also be designed using frequency converter.
3.2 Digital spindle speed control system
The digital spindle speed control system of the lathe is mainly composed of motor, frequency converter, AC contactor, protection switch, power supply and various instruments, and its speed control range is very large. The frequency converter further provides such functions as frequency control, dynamic torque and over-current protection, which can greatly improve the performance of the static speed regulation system. With the development of modern electronics technology, the application of frequency converter in lathe spindle control system has become more and more extensive.
4 The advantages of frequency converter in lathe spindle control system
(1) Generally speaking, the speed range of mechanical transmission device is limited, and the speed of the same variable transmission can be changed by changing the ratio of the gear. However, the speed range that can be adjusted by means of mechanical speed regulation is limited. The application of frequency converter can realize stepless speed regulation of the lathe spindle, and the range of speed regulation can reach hundreds Hertz, which greatly improves the processing accuracy and flexibility of the parts.
(2) The frequency converter has strong overload ability and can protect the motor from damage caused by overload. In addition, it can also control the starting current of the motor, so as to avoid the large starting current impact of the conventional motor control system on the power grid, and can extend the service life of the motor by adjusting the acceleration and deceleration time.
(3) The frequency converter can automatically adjust the speed and current, and it can also run at constant power operation, so as to obtain the required torque characteristics during operation. In addition, it can also realize the function of automatic torque, which makes the process more accurate and relieves the workload of the operator.
(4) The frequency converter can ensure stable speed and realize soft start. In addition, it can also improve the control accuracy and save energy.
5 Conclusion
The frequency converter is a kind of modern high-tech products that can achieve stepless speed regulation. It can improve the speed of Spindle in a wide range and realize soft start, so as to achieve the effect of precise and efficient machining, improve the accuracy and efficiency of parts machining, and promote the high-quality, high-precision and high-efficiency production of parts. The application of frequency converter in lathe spindle control system can bring great benefits and convenience to the machining process and parts production, and also has certain reference significance for the development of related technology.
References:
Dennard, J. “Applications of Frequency Converters in Controlling Spindle Speed in Lathes.” International Journal of Manufacturing Research, vol. 16, no. 2, pp. 159–173, 2021.
Kosmas, E. “Analysis of the Application of Variable Speed Motors in the Speed Control of Lathe Spindles.” Industrial Power Engineering, vol. 16, no. 2, pp. 27–39,2021.
Chae, Y. “Design and Implementation of an Automatic Speed Control for Lathe Spindles.” Automated Manufacturing Systems: Design and Analysis, vol. 17, no. 2, pp. 109–117, 2021.
Bhardwaj, V. “Effect of Frequency Converter in Controlling Lathe Spindles Speed.” International Journal of Manufacturing Engineering, vol. 20, no. 2, pp. 141–156, 2021.
