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2022-08-16
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Integrated application of delta mechanical and electrical products on four axle independent suspension roving frame

Abstract: traditional roving frames mostly use cone wheels (commonly known as iron cannon) and differential box devices. The mechanical structure is more complex, and the method of adjusting spinning parameters depends on changing gears, which can no longer meet the customer's needs for high-speed, high-quality, large volume and man-machine friendly roving frames; At the same time, the differential development of modern textile technology and technology requires that the control data can be adjusted quickly and effectively in the spinning process. At present, the independent four-axis suspension roving frame developed by our company meets this requirement very well

key words: roving frame; PLC; Servo; Frequency converter; Hmi

I. Introduction

roving frame is a device that processes the cooked sliver after drawing into roving with different number and twist for spinning spinning by spinning frame. It is suitable for combed and combed cotton fibers, chemical fibers below 60mm and other blended fibers

compared with other traditional spinning equipment, the technological progress of roving frames in China has lagged behind in the past few decades. Among them, many roving frames have been changed into one-way roving frames, which are affected by the progress of spinning technology and interfered by the debate on the development of super drafting spinning frames. Since the 1990s, with the maturity of the advanced mechanical structure and control theory of roving frames, high-speed, high-quality, large volume and man-machine friendly roving frames that meet the requirements of customers have developed rapidly

roving frame is divided into supporting spindle type and suspension spindle type according to the different doffing process; According to the number of motor shafts, suspension roving frames are divided into two shaft, three shaft, four shaft and seven shaft roving frames; Four axle suspension roving frame is the focus of this round of technological development. Four axle suspension roving frame is divided into differential box type and four axle independent type; Based on Delta's mechanical and electrical products, this paper expounds the technical points of the four axis independent suspension roving frame composed of frequency conversion and servo.

II. Mechanical structure and related processes

1 The overall structure of four axle independent suspension roving frame is shown in figure 1:

Figure 1 whole machine figure

2 Transmission structure and process

transmission structure is shown in figure 2:

Figure 2 transmission structure

Figure 1 Winding servo motor 2 Roller servo motor 3 Spindle wing variable frequency motor 4 Longjin lifting motor

5 Roller device (its drafting principle is shown in Figure 3) 6 Spindle wing assembly 7 Winding device

8 Dragon tendon 9 Universal joint

Figure 3 roller drafting principle

according to the requirements of the spinning process, the roving machine draws the cooked sliver through the roller, pulls out the yarn from the front roller, and the spindle wing rotates at a constant speed for twisting; At the same time, the winding system drives the bobbin to rotate, and the twisted yarn is wound on the bobbin according to the requirements of winding forming. Because the pulling speed of the front roller is constant, the winding speed decreases with the increase of the winding diameter. At the same time, the Dragon rib slowly rises and falls, supporting the upper bobbin to move up and down, and cooperating with the winding device to wind the yarn layer by layer on the bobbin until it reaches the preset number of layers or yarn length

in fact, the complete suspension roving frame should also include a cleaning device: the suspension roving frame generally adopts an active rotary upper and lower cleaner. Because of its independent structure, the working side should not exceed ± 1% The formula is relatively simple and will not be repeated in this article

III. electrical system architecture based on Delta Electromechanical Products

1 The framework of the electrical system considers the four axis independent suspension roving frame. The key of the control system is the synchronous proportional linkage of the four axes to simulate the process of synthesizing the speeds of each axis by the differential box of the two axis roving frame; During the operation of the four axis independent suspension roving frame system, the speed of each axis requires high responsiveness and stability. At the same time, the motor requires rapid and effective strain capacity for the reasonable change of external load

based on the above technical characteristics of the equipment and the high-quality requirements of customers, combined with Delta's complete and comprehensive product line, we choose Delta Eh2 series PLC as the main control, and delta ve Series High-Performance vector converter to control the spindle and wing shaft; Delta a+ series high-power servo system controls the winding shaft; The roller shaft and Longjin shaft are controlled by delta AB series servo system respectively; The touch screen is Delta a series true color interface

2. The overall structure of the electrical system

the constructed electrical system is shown in figure 4:

Figure 4 electrical system structure

3 Main controller functions

a. touch screen: the parameter setting amount of four-axis suspension roving frame is large, and this screen can intuitively and conveniently set and monitor various parameters

b.plc:eh2 series type, fast operation speed, support 4-way high-speed pulse output, stable and reliable, and can expand i/o points according to the control process

c. roller servo: provide roller shaft power with constant speed, and the size depends on spindle wing speed and twist

d. winding servo: it provides winding power of bobbin, and the speed decreases with the increase of winding diameter of yarn

e. dragon tendon servo: provides dragon tendon lifting power. The smaller the lifting speed, the denser the yarn winding

f. spindle wing frequency conversion: provide spindle wing rotating power, with constant speed, which is set by the touch screen; The frequency conversion system is equipped with a speed feedback PG card, and the motor is equipped with a delta encoder to realize closed-loop control. Considering that the configuration of the roving electromechanical control box is far from the machine head and the electromagnetic environment on the application site is complex, it is recommended to choose a differential encoder

4. Peripheral control circuit

according to the process requirements, multiple groups of operation boxes are installed in parallel on the roving body, and each group of operation boxes is equipped with start, stop and jog buttons, which can start, stop and jog the whole machine, so as to facilitate the operation of the shift operator; In the process of spinning, the broken yarn and broken sliver require automatic shutdown, so photoelectric sensors are installed to detect whether the sliver works normally; After the spinning molding is completed, the Dragon rib automatically drops to the doffing position, which is convenient for the car stopper to quickly remove the spindle; At the same time, after the spindle is removed and the roving is finished for one time, install a new bobbin again, operate the relevant buttons on the touch screen, require the rib to automatically rise to the initial winding position to stop, manually wind the yarn that has passed through the spindle wing at the initial winding position of the bobbin, operate the start button, and the new spinning process begins. This requires that the doffing position detection switch be added during the up and down travel of the rib Initial winding position detection switch. Considering that the up and down travel of the Dragon tendon cannot exceed the limit value, the upper and lower limit detection switch of the Dragon tendon must be installed

the above control points are directly connected to the PLC input points, and the control logic is calculated and processed by PLC

Figure 5 parameter setting interface of touch screen program

IV. debugging difficulties, key points and Countermeasures

1 Yarn tension control

four axis suspension roving frame, the yarn stretched out from the roller needs to pass through the spindle wing to form a twist and then wind it on the bobbin. The whole process is a dynamic process; Due to the limited twist, the limit tension of the yarn is small. In the whole spinning process, due to the fluctuation of the synchronization of the proportional linkage of the transmission machinery and the error between the theoretical value and the actual value of the yarn tube diameter at any time, the yarn discharge position fluctuates up and down (as shown by the arrow in Figure 3). The large fluctuation not only affects the forming quality of the yarn spindle, but also causes the whole machine to stop and affects the spinning efficiency

at present, the industry mainly solves the above problems in two ways:

the first is that the roving tension is detected by the tension CCD sensor and fed back to PLC operation

this method reduces the difficulty of core calculation and simplifies the control calculation of winding and rib shaft. However, due to the high environmental requirements of CCD detection in the actual use process, the mirror must be kept clean, and in the face of market cost pressure, this solution is not popular, but it is worth paying attention to

the second kind: under the standard theoretical calculation formula, add the tension compensation program, and then fine tune the spinning speed of the bobbin and the lifting speed of the rib, so as to achieve the purpose of adjusting the roving tension. At the same time, different compensation coefficients are automatically invoked for different yarn requirements. It is commonly used to compensate the winding speed of micro adjustment

this method has small cost, obvious effect, does not depend on the detection of external devices, and has good flexibility. However, during debugging, it should be tested repeatedly to continuously accumulate the correction coefficient values of different yarns in different layers. This method is adopted in this case

2. Power failure memory of Longjin position

when spinning, when the spindle winding is not completed, the external power failure of the system often exists. After being powered on again, the roving machine is required to continue spinning with the position and parameters before the power failure

since most servo system drivers in the market are incremental encoders, the current position of the shaft cannot be memorized after power failure; In this case, the output port of PLC and servo driver encoder is connected through 4N25 optocoupler, and the position value before power failure is memorized through PLC power-off memory area. The connection mode is shown in Figure 6

Figure 6 Longjin servo encoder is connected to PLC after 4N25 conversion

3. Control of the start and stop of the whole machine

after the roving machine is in the initial stage of spinning, you can continue the experiment by calling out the last experiment. When it is about to be completed, the spindle radius is relatively small or large. At this time, if it operates at the highest speed of the screen, the centrifugal force of the yarn at the winding edge is quite different from the middle section of the spinning, It is not conducive to the formation of high-quality spindles. This requires that the speed of the whole machine be reduced in the initial stage of spinning and when it is about to be completed, so as to reduce the end breakage rate and improve the yarn quality. The automatic speed conversion program of each spinning stage must be designed in the program

Fig. 7 middle section of spinning forming

v. conclusion

the four axis independent suspension roving machine developed based on the above scheme has been successfully developed in a textile machinery factory in Shandong, with the highest spindle wing speed of 1350r/min, symmetrical spindle forming, good yarn layout consistency, and the length of yarn formed at one time can reach 3200m; Twist, spindle forming angle, forming length and spinning length can be set flexibly. The spinning tension is more stable, and the end breakage is less than 0.5 pieces/set · hour at the spindle speed of 1100r/min. It has the functions of automatic doffing and automatic finding of the initial winding position, which effectively reduces the labor intensity of the car stopper, improves the labor efficiency, and has a broad market prospect

Delta has a complete product line of industrial controllers such as frequency converter, PLC, servo system, man-machine interface, encoder, etc., providing customers with advanced and comprehensive solutions. For the roving machine industry, delta can provide two axis, three axis, four axis frequency conversion or servo system overall solutions, and can meet the personalized requirements of customers in the high-end aluminum green lightweight market. Based on the continuous progress of technology in the textile industry, The textile industry application department specially established by the company serves the textile industry

references

1 Zhou Qi Introduction to textile machinery foundation Beijing: China Textile Press 2006.

2 Zhou Bingrong Spinning machinery Beijing: China Textile Press 1999.

3 Delta vfd-ve frequency converter user manual Zhongda Diantong Co., Ltd 2007.

4 delta Asda AB series servo driver application technical manual Zhongda Diantong Co., Ltd 2007

5 Delta dvp-plc application technical manual (program) Zhongda Diantong Co., Ltd 2006 (e ball screw has almost no self-locking property, while trapezoidal screw has a fixed self-locking property nd)

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