Aiming at the optimization of the spindle process parameters, the importance of the spindle speed setting on the head retention rate during the operation of the mechanical lifting collective doffing spinning machine was discussed. The combination of theoretical analysis and field debugging was used to calculate the spindle speed setting. It is pointed out that the optimization of the spindle process parameters can reduce the end break rate of the spinning frame, reduce the labor intensity of the spinning workers, and improve the rate of head retention, work efficiency and output of the cotton spinning mill.
Keywords: ring spinning machine; spindle speed; mechanical lifting; head retention rate; end break rate
Influence of spindle speed on spinning efficiency
At present, mechanical lifting steel ring spinning frames still occupy a large proportion in textile mills. In order to reduce the labor intensity of stoppers, reduce the breakage rate during driving and doffing, and increase the retention rate when driving, it has become a major research topic for each textile mill and textile machine manufacturing enterprise. In the spinning process, the end break rate is related to many factors, such as: spinning raw materials, spinning speed, temperature and humidity, management, technology, etc. Among them, the spindle speed is the main factor affecting the end break rate. The author combines theory with field debugging to analyze the influence of the spindle speed of the ring spinning machine on the head retention rate.
The traditional manual doffing is mainly by manually pulling the yarn back to the spindle, and when the new bobbin is pressed onto the spindle, the ejection on the spindle is suppressed to achieve the purpose of retaining the head. The collective doffing on the market today is to keep the head by winding the yarn onto the waste silk reel of the aluminum sleeve spindle during doffing. If you want to achieve the best retention effect, and the full body yarn will not go back to the spindle when the full yarn is pulled out, it is best to ensure that the number of turns of the cover yarn is 1-2, and the number of turns of the cover yarn It is mainly adjusted by the spindle speed during doffing.
Theoretical Calculation of Spindle Spindle Speed
In order to improve the head retention rate during driving, to prevent the problem of spindle rewinding during doffing, and to prevent spindle rewind from hindering the traveller's movement, we need to adjust the combination of the number of loops of the wrap yarn and the waste silk reel during doffing. In addition to the electrical reasons, we mainly analyze the doffing spindle speed and the doffing ring speed. The spindle speed during doffing of the spinning frame is mainly set based on data such as twist degree D, mechanical lifting sprocket and worm gear transmission ratio y, servo motor frequency Z, ring plate lifting motor speed and power.
Take JWF1510 spinning frame manufactured by Jingci Yuci Branch as an example. Figure 1 shows the mechanical part of the ring box that controls the doffing of the ring plate.
In order to increase the spinning output and adapt to different spinning numbers, the sprocket 1 can be replaced with 15 teeth, 17 teeth, 21 teeth, etc. in time. Before and after the sprocket 2 and sprocket 3 are exchanged, the ring plate The descending speed is as follows.
15 teeth: before replacement, the ring plate descending speed is 53 mm / s, after replacement, the ring plate descending speed is 79.5 mm / s.
17 teeth: before replacement, the ring plate descending speed is 60 mm / s, after replacement, the ring plate descending speed is 90 mm / s.
21 tooth: before replacement, the ring plate descending speed is 74 mm / s, after replacement, the ring plate descending speed is 111 mm / s.
According to the calculated length difference above, when the step-up motor sprocket is 15 teeth, the same twist is 495 twists / m. In order to meet 1 turn of the covered body yarn, the linear speed at the time of doffing = the ring plate needs to descend straightly Yarn length + length difference = (79.5 × 2 + 24.6) mm / s = 1 1m / min, doffing spindle speed: 11m / min X 495 twist / m = 5 445 r / min.
When the step-up motor sprocket is 17 teeth, the same twist is 495 twists / m. In order to meet 1 turn of the body yarn, the linear speed during the doffing of a steel ring plate and the straight down of the ring plate need to be + the length difference = ( 90X2 + 24.6) mm / s = 12.27 m / min, doffing spindle speed: 12.27 × 495 twist / m = 6 073 r / min.
When the step-up motor sprocket is 21 teeth, the same twist is 495 twists / m. In order to meet one wrap of the body yarn, the linear speed at the time of doffing = the length of yarn + the difference in length required for the ring plate to descend straightly = ( 111 X 2 + 24.6) mm / s = 14.8 m / min, doffing spindle speed: 14.8 X495 twist / m = 7 326 r / min.
According to the calculation of the 13-tooth sprocket above, the driving speed and spindle curve after replacing other kinds of sprocket can be obtained from the doffing spindle speed.
Concluding remarks
This article calculated the setting of spindle speed through the combination of theoretical analysis and field debugging. The theoretical calculations have been verified in the field, and the effect is significant for the mechanical lifting ring ring spinning machine. By optimizing the process parameters such as the doffing spindle speed and the spindle speed curve, the yarn breakage can be greatly reduced. Rate, increase the retention rate of driving, increase production, and reduce labor intensity.
