The automation technology of domestic textile industry has been improved significantly since the reform and opening up. Most of the textile equipments adopt VVVF technology and PLC technology, and a considerable part adopts the computer, SCM, AC servo system as well as the HMI interface and Fieldbus technology, realizing the mechatronics of mechanical products and paving the way for the textile machine to be faster and more continuous and automated.
As a high-tech equipment in the integration of automatic control, digital processing and storage technology, computerized quilting machine plays an increasingly important role in the textile, bedding and other industries, which is highly praised by customers. Currently, there are several types quilting machine: computerized single-needle quilting machine, multi-needles quilting machine, and computerized ultrasonic quilting machine and so on. Compared with traditional mechanical quilting machine, there is a powerful digital processing system in modern computerized quilting machine, which could handle various input complex patterns, with incomparable indicators, such as the processing precision, production speed, mechanical properties and noise pollution. In addition, there are also some other convenient functions, such as wire broken detection, spindle detection, automatic rail search, pattern management, etc., which could highlight the technical advantages of computerized quilting machine.
Ⅱ. Process Requirements
First, use CAD software to generate embroidery patterns, and then put the disc with embroidery program and patterns into the computer disk drive. While under processing control, computer will transform the pattern coordinate value into electrical signals corresponding to displacements in silk frame X, Y direction and output three-phase six beat signal after sending them to the X & Y SCM system to perform motor speed rising or decreasing. The power amplifier box of line motor will perform power amplifier, and two X, Y stepper motor will drive the silk frame to complete feed movement of X, Y direction; meanwhile, inverter will drive motors, driving the needle to move up and down, so that the embroidery will be carried on continuously.
Variable frequency motor drives the transmission mechanism of machine head through a belt, and the special mechanism of head will make the traction mechanism and needle drive spins to move up and down, puncturing fabrics; the hook in hooking mechanism rotates, making spins bypass the bobbin with bottom line; take-up mechanism conveys spins and tightens stitches, preparing the spins for the next stitch. X, Y stepper motors drive flat frame and fabric to do flat motion by synchronous toothed belt and other mechanisms, sending each stitch point on the fabric to needle embroidery machine. The coordination of needle up/down movement and the direction, displacement and moving speed of silk frame makes the spins and bottom line twisted, to perform dual-thread lock stitch on the fabric. When it continues, the patterns of computer embroidery are completed.
Ⅲ. Solutions of VEICHI Products
(1) Faster frequency response provided by high speed processors
AC80C inverter adopts DSP motor drive specialized CPU, providing high control accuracy, fast frequency response and good dynamic characteristics. Computerized embroidery machine requires the spindle speed to be set by LCD, and after dealt by the SCM, 0 ~ 10V analog signal is output to inverter by D/A conversion module. Inverter quickly runs to the required speed according to the value of analog signal to meet the requirements of embroidery.
(2) Large torque output in low frequency under VC control
The belt of 1:3 transmission ratio is used between motor and spindle, and the frequency is changed to constant torque output under the fundamental frequency. Previously, inverter with V/F control has to be set corresponding torque boost when considering the large start-up torque of load. And if the torque boost is set too high, there will be over excitation in low frequency with light load, leading to big current and motor overheat, and even affecting the normal operation of equipment. By setting parameters, AC80C inverter could ensure the good torque output of the motor at low frequency, and meet the continuous line of embroidery machine in low speed.
(3) Good braking ability to achieve the quasi stop of needle
In the process of embroidery, it is necessary to move the silk frame and fabric to complete the whole picture. During the movement, needle is required to stay at the highest position, which requires the DC braking function of inverter. The accurate DC braking function of AC80C inverter provides a wide range of adjustment, and users could adjust parameter settings according to the load inertia to meet the operation requirements.
The computerized embroidery system with VEICHI AC80C inverter could achieve steady and reliable operation, and gain high economic benefits for customers. And VEICHI overall solution is highly praised by customers through the actual production test. The specific advantages are as below:
1. Large start-up torque in low-frequency, to ensure good torque output of motor in low frequency, which meets the continuous line of embroidery machine in low speed;
2. Good braking performance , to achieve the quasi stop of needle;
3. High frequency control accuracy and fast response, to ensure the speed accuracy of computerized embroidery machine.