AC Servo Driver for Industrial Sewing Machine
With the large-scale development of garment industry, industrial sewing machine develops rapidly with annual production of industrial sewing machine in millions. In order to improve the sewing efficiency and quality, clients want the sewing machine to have automatic thread trimming, automatic loose thread, automatic backtrack, automatic dial thread and automatic foot lifting and depressing, etc. Now many companies are studying electromechanical integration and digital industrial sewing machines, which have shown a favorable development trend in terms of scale production and market share.
Sewing machine control system
Industrial sewing machine control system is a comprehensive and strong technology, which involves many aspects of knowledge, such as the principles of mechanical and electrical equipment, operation technology and so on. As the core running component in industrial sewing machine, the servo system plays a key function in running of this equipment.
This control system mainly includes special controller, AC servo system and stepper motor system, in which the controller mainly consists of main control board and two step drive boards. So it can directly sends pulse to control stepper motors in axis-X and axis-Y, while the needle is controlled by servo motor through needle bar directly connected with coupling.
After AC servo motor is used, the equipment runs smoothly with high positioning accuracy and the needle stops rapidly and accurately. One-shot positioning, needle stopping at high speed without shaking. Large speed adjustable range within 0- 3000 rpm. Rapid responding to speed adjustment, speed fully tracking foot pedal control, speed increasing and decreasing without any drag. Large torque, multi-use machine which can meet thin materials and thick materials sewing requirements. Low noise and vibration, high efficiency. Perfect fault detection and double protection function for hardware and software (including overcurrent, under voltage protection, etc.), reliable operation of system. Full-automatic start-up self-detection function, switch power supply, wide voltage application range. Integration design, convenient installation and maintenance.
AC Servo System Design
The function of servo system is to control link mechanism by coupling, so as to control needle up/down. Thus action requirements of servo motor mainly has two aspects: High seeking action when starting up and smooth start-stop action when running normally.
1. High seeking action when starting up
Servo motor connects with load directly through coupling and one sector inductor is fixed on coupling while there is one photoelectric sensor above coupling. When equipment is energized, controller sends SERVO ON and pulse signals to servo, then servo motor rotates clockwise viewed from loading direction and receives up signals from photoelectric sensor and meanwhile stops sending pulse to servo. Within servo responding period, the controller stops at high position of needle.
2. Smooth start-stop action when running normally
When servo motor runs normally, the speed is about 3000 rpm and it is necessary to track the foot pedal switch on/off by operator to perform start-stop action and the equipment must stop timely at high position, otherwise, the thread sweeping and trimming action cannot be finished. Meanwhile, output torque from motor should be enough, because the customers always use very thick cloth to test the sewing effect.