Application practice of drawing frame with self le

Application practice of drawing frame with self leveling device

fa326 drawing frame is a high-speed drawing frame with self leveling device produced by Shenyang Hongda Textile machinery company. Our company purchased two sets at the end of 2001, and equipped with BYD short segment self leveling device produced by Luoyang 613 Institute, which adopts the single blending process after finishing and is used to spin JC14.5 variety. After more than two years of use, the equipment operates normally and the product quality is stable, It is very suitable for the single and parallel process after finishing. The following is a brief introduction to the performance characteristics, process performance and use management of FA326 drawing frame:

I. main technical parameters of FA326 drawing frame:

l, eye count: 2

2, mechanical speed: up to 600 meters

3, suitable fiber length: 22 ~ 76mm

4, feeding type: overhead positive feeding

5, drafting type: three up and three down pressure bars plus guide roller curve drafting

6 Total draft ratio: 5.6 ~ 9.7 times

7. Pressurization type: Cradle spring pressurization

8. Roller diameter/mm: upper roller: 34, 34, 30, 34

lower roller: 45, 35, 35

9. Barrel changing type: rear in front out chain push rod type

10. Self leveling type: open loop self leveling

II. Main structural features of FA326 drawing frame:

l. Transmission mode: a large number of toothed belt drives are used, The transmission is more stable and the noise is low. The drafting system adopts circular arc toothed belt transmission, which has strong load bearing capacity and stable transmission without clearance, which is conducive to improving the drafting quality

2. The main motor adopts frequency conversion speed regulation, which is convenient to adjust. The control system adopts PLC control, and the whole machine has a high degree of automation

3. Drafting mechanism: adopt the three up and three down pressure bar plus guide roller curve drafting type. The cotton first passes through the back area for pre drafting, and then enters the main drafting area. The pressure bar plays a role in strengthening the control of slow fibers in the main drafting area, which is conducive to improving the drafting quality

4. The guide bar feeding adopts the overhead type to actively feed people in a clockwise direction. The head eye and tail eye of the car are separately driven by the flat belt. The cotton sliver is actively fed through the guide bar roller. The cotton sliver is arranged in a row on the guide bar roller with the help of the sliver separator. The guide bar part is equipped with three groups of optoelectric self-stop detection heads. This guide bar structure is easy to operate, which can effectively reduce accidental drafting, avoid flying flowers, and is conducive to improving the quality of cotton sliver

5. Automatic barrel changing: a separate motor drives the chain to push out the full barrel and feed the empty barrel at the same time, which greatly reduces the labor intensity of workers

6. The air suction system adopts an independent cotton suction box, which is located on the central line outside the host, and can arbitrarily adjust the size of the air volume, and can make the air suction effect of the left and right eyes consistent, which is very beneficial to reducing yarn defects

7、 Equipped with by produced by Luoyang 613 Institute [) type short segment self leveling device adopts all detection and all leveling methods, which can effectively control the unevenness of short segments.

III. The process configuration can achieve the load control setting: spinning jcl4.5

l, cotton distribution situation

2, process flow

fa009 automatic cotton gripper -fal05a2 single axial flow cotton opener -fa029 multi bin cotton mixer -fal79 cotton feeder -fall6 main trash remover -fal78a cotton feeder -fa23l carding machine (with ft024 leveler) -Fa306 pre merging -e32 strip merging -e62 comber -fa326 drawing frame (with self leveling) -fa425 roving frame -fa506 spinning frame

3. Process commissioning

due to the self leveling device, we adopt 8-piece merging in one drawing. The motor adopts frequency conversion speed regulation, and the maximum speed can reach 600m/min. in combing production, considering the supply of front and rear matching tables and the requirements of yarn quality, we choose the speed of 300m/min. Orthogonal tests were carried out on the main process parameters affecting the quality, such as the holding distance of the roller, the drafting multiple of the rear area, and the high and low position of the pressure bar. The test results are as follows:

after the test, the final process was determined as follows: the holding distance of the front area is 42.5mm, the holding distance of the rear area is 47turn, the drafting multiple of the rear area is 1.3, and the pressure ring is Φ 13mm。

IV. leveling setting of BYD type self leveling device

byd type self leveling device is an open-loop short segment self leveling device suitable for high-speed drawing frame. It adopts the method of full detection and full leveling, and is controlled by two eyes independently. It can even the uneven segments with a length of more than 1.5 ~ 2cm in the feeding sliver. It has perfect system self detection function and sliver production function, and can display a number of processes, quality Output and other data, and can send an alarm and stop automatically according to the quality limit set by the user

in the BYD short segment self leveling device, it is very important to set various mechanical parameters and calibrate the detection sensor, dead zone length and magnification. Their accuracy is directly related to the time delay synchronization and accuracy of the leveling effect to compensate the weight deviation of sliver, and it is the key to the leveling effect of BYD device

1. Process parameter setting:

byd can play its role only when the drawing frame process design is correct and accurately input into the BYD system. Improper process setting will lead to serious deterioration of the sliver quality. After the test, the main process parameters are set as follows: pre draft times 1.3, pre draft holding and with heat barrier continuous honeycomb structure distance 47mm, main draft holding distance 42.5mm,

2 Reasonably set the dead zone length: the dead zone length is the distance between the jaw of the feeding detection mechanism of the drawing frame and the fiber speed change point in the adjustable drafting area, which directly affects the time difference between the detection of the sliver signal from the concave convex roller sensor and the action of the servo motor. It is one of the most important system parameters of BYD, and it directly affects the CV% of the sliver and the weight unevenness index of the sliver. To determine the dead zone length, the sliver test should be done, and the dead zone length should be determined according to the jumping curve of the sliver. Because the dead zone length is related to the drafting multiple of the back zone, the center distance of the middle and rear rollers and the length of raw cotton, the dead zone length of both eyes needs to be carefully adjusted every time the variety is changed or the process is adjusted

3. Reasonably select the magnification: the magnification affects the proportional relationship between the detection amount and the evenness amount, which is another important parameter of BYD. It directly affects the weight deviation and weight unevenness of cotton sliver production. It is related to the elasticity of feeding sliver and the pressure of concave convex roller. The magnification of both eyes needs to be carefully adjusted every time the variety is changed or the process is adjusted

4. Choose an appropriate concave convex roller. The concave convex roller is one of the most important factors affecting the leveling effect, because the thickness of the concave convex roller directly affects the displacement change of the displacement sensor, thus affecting the normal work of the leveling system. When the feeding ration increases, choose a thicker concave convex roller. On the contrary, use a thinner concave convex roller, and the corresponding cotton collector and cleaning shovel should also change with it. In addition, in the production process, it must always maintain its accuracy and surface cleanliness, and regularly remove the dust and wax on its surface and detection surface to ensure its good operation

5. The setting of self leveling cannot be done once and for all. The process must be continuously optimized and improved around self leveling in order to play its most effective role. Under the following circumstances, the leveling system should be properly adjusted (except for the ball screw that normally adjusts the broach transmission mechanism to be set vertically when the system is damaged)

(1) when the sliver count changes (2) when the raw material changes (3) when the output speed changes (4) when the drafting multiple changes (5) when the concave convex roller changes (6) when it has not been driven for a long time

3. Comparison of yarn quality between FA326 one pass and fa306 two pass

test conditions: the feeding sliver is the same, the roving and spinning adopt the same platform and the same spindle, FA326 with BYD self leveling is single pass merging, and FA206 is two pass merging. The test results are shown in the following table: the test variety is jcl4.5

result analysis:

1. The drawing frame with self leveling device can automatically and effectively detect the unevenness of feeding sliver and realize the detection and adjustment of draft multiple, The weight deviation of the feeding sliver is corrected to make the output sliver uniform, so the weight unevenness of the sliver can be well improved

2. Eyd adopts an open-loop control mode. By using a high-performance microcomputer system and a fast corresponding full digital AC servo system, it can realize rapid leveling of the weight deviation of the feeding sliver, and the leveling segment can reach 1.5 ~ 2.0cm, which can accurately eliminate the lap joint of the comber (leveling the binding wave cm generated on the comber), and reduce the sliver CV%

3. After combing, single drawing is adopted, which conforms to the arrangement law of fiber hooks in the spinning process, so that most fibers in the roving fed to the spinning frame enter the spinning drafting area in the form of hooks, so that the fiber straightness is effectively improved, so as to improve the evenness CV%, strength and strength CV% of the yarn

4. After using FA326 drawing frame with self leveling device, the number of shunting per shift is significantly reduced, which not only reduces the labor intensity of the operation repairman, but also reduces unnecessary equipment wear. At the same time, because the drawing frame with self leveling device is to detect and repair, it basically eliminates the production of defects caused by lag

5. After finishing, adopting the single merging process can not only reduce the amount of equipment and floor area, but also reduce labor. At the same time, it can also overcome the disadvantage that the combed strip is too ripe and rotten after two layers of merging, which is easy to cause head breakage

VI. use management:

1. In the process of use, attention should be paid to ensure that the tension of the toothed belt is appropriate. If the toothed belt is too loose, there will be tooth skipping, resulting in coarse and fine cotton slivers, affecting the quality of the cloth. If it is too tight, it will cause displacement of the toothed belt, resulting in poor operation. At the same time, the toothed belt should be kept clean, not stained with oil, and the toothed belt pulley should be kept flush with the tension pulley, otherwise it will have a negative impact on the evenness, and serious mechanical waves will occur

2. Regularly replace the oil in the differential gear box

3. In order to ensure the uniformity quality, BYD generally needs simple calibration every two weeks and comprehensive calibration every three months

4. The self leveling device can be slightly adjusted, but it should not be too large, so as not to affect the spinning quality. When the feeding strip weight deviation exceeds 5%, the process of the previous process or the process of this process should generally be adjusted

5. Pay attention to the quality of cotton sliver in the daily production process. When the deviation of sliver weight is not greater than 0.5%, generally do not adjust it. When it must be adjusted, the amount of adjustment at one time should not be too large

6. The concave convex roller is the most important factor affecting the leveling effect. The radial runout and end face wear of the concave convex roller should be checked regularly. At the same time, its surface must always be kept clean, and the dust and wax on its surface and detection surface must be removed regularly to ensure its good operation

7. The displacement sensor shall be checked at least once a month, mainly to check whether its detector head moves flexibly, whether it is stuck, whether the spring can work, and whether the radial looseness is too large

8. The equipment has a high degree of electromechanical integration, and the professional level of process technology and electrical maintenance personnel should be improved accordingly, so that the equipment can give full play to its potential

VII. Conclusion

the traditional drawing frame only improves the "three degrees" of fiber through merging and drafting. Its sliver weight unevenness is obtained by frequently changing the cone on the drawing frame to control the weight of cooked sliver, while the drawing frame with self leveling device adopts the finishing single merging process, which can not only reduce the number of merging passes and make it conform to the fiber hook arrangement law in the spinning process, And it can reduce and eliminate the unevenness caused by the previous process