The mechanical transmission method of roving frame is a method commonly used by most domestic cotton spinning enterprises. Our company currently has 32 mechanical transmission roving frames. After years of use, some problems have gradually appeared in the operation of the equipment, such as twist during the spinning process. The unevenness rate is too large; when spinning low-twist varieties of chemical fibers, the full yarn doffing and end-breakage rate increases; yarn leakage; the lower ribs are blocked or stopped, and other phenomena occur from time to time, seriously affecting the workshop production supply and spinning quality . Therefore, transforming the transmission mode of the roving frame is an important way to improve the automation and productivity of the roving frame.
1. Main problems existing in mechanical transmission roving frame
1.1 The transmission system is complex
(1) Spindle flyer transmission: The main motor drives the main shaft to drive the spindle flyer.
(2) Drafting and cotton guide transmission: The spindle drive twist conversion gear is transmitted to the upper and lower drafting cleaning and cotton guide devices through the intermediate wheel.
(3) Bobbin transmission: The main shaft is transmitted to the upper iron cannon through the twist gear, and the lower iron cannon drives the bobbin through the differential box and the universal device.
(4) Lower rail lifting transmission: The spindle is transmitted to the lifting box through the twist gear, upper iron cannon, lower iron cannon, complex-structured forming device, and reversing box to the lifting box to control the lifting of the lower rail.
1.2 There are many transformation gears
(1) Total drafting gear: used to change the roving weight (count).
(2) Rear draft gear: used to change the draft ratio of the rear area.
(3) Twist conversion gear, paired twist gear: used to change the twist of roving.
(4) Main lifting gear and paired lifting gears: used to change the axial winding density of roving.
(5) Tension adjustment gear and tension replacement gear: used to change the radial winding density and control the spinning tension.
During product changes, these gears often need to be replaced. As our company mainly spins differentiated fibers, product changes are very frequent. Some transmission gears and transmission shafts are worn to varying degrees. Improper gear meshing or replacement can easily lead to quality problems. .
1.3 High technical requirements for equipment maintenance personnel
The front transmission and rear transmission of the mechanical transmission roving frame are complex and must be maintained by skilled maintenance workers. There are many disassembled parts, such as upper and lower iron cannons, differential boxes, reversing boxes, forming devices, etc., and the equipment operation is After a few years, some parts will wear out. If not replaced in time, it will easily cause mechanical failure, yarn leakage, uneven twist, poor evenness and other quality problems, which will seriously affect the normal operation of the roving frame.
1.4 Mechanical transmission roving frame consumes a lot of accessories
After a few years of normal operation of the mechanical transmission roving frame, the forming support, balance frame, upper and lower iron cannon bearings and flanges, head machine rear transmission shaft, electromagnetic clutch in the reversing box, differential box, lifting transmission gear, iron cannon Belts and other components often appear worn or damaged, resulting in excessive consumption of machine parts. According to rough statistics, the consumption of main machine parts for each mechanical transmission roving frame in our company is at least 800 yuan per year. Calculated based on 32 roving machines, the annual consumption is The maintenance cost is about 26,000 yuan.
2. Transformation content
After inspection and comparison, we have carried out technical transformation of the mechanical transmission roving frame. After more than half a year of trial, we have shown obvious advantages in equipment failure rate, quality, operation and other aspects. The main contents of the transformation:
(1) Remove all the transmission gears, differential box, reversing box, and lifting transmission box in the front of the car. The upper and lower iron cannons, each transmission shaft, and the forming device at the rear of the machine also need to be removed.
(2) The four major transmission systems of the roving frame were changed to be driven by four motors, equipped with a human-machine dialogue operation display.
3. Practical results after transformation
(1) The roving frame was transformed to produce R40 varieties. After many comparative tests, the Uster evenness value of the roving was reduced by 0.2 percentage points on average, and the CVb of the roving was basically controlled within 4.0.
(2) The problem of uneven reversal tension of the roving has been well controlled. By testing the twist at the upper, middle and lower parts of the roving, the unevenness of the twist has been significantly improved. There is no longer any problem of drafting failure or end breakage after the transformation of the parking space. Phenomenon.
(3) The roving length is more accurate, the elongation is reduced from the original 1.5% to less than 1.0%, the consistency of the full yarn length is improved, and the difference is basically controlled within 20 meters.
(4) The failure rate is reduced and the consumption of machine parts is reduced.
(5) Employment reduction. After the transformation, the number of maintenance personnel in our company has been reduced from 8 to 6 (50,000 spindle scale). The employee salary is calculated as 25,000 yuan per year, which can save 50,000 yuan per year.
(6) The vehicle speed increases and the output increases. The vehicle speed is increased from the original 23 meters/minute to 26 meters/minute, the output per unit can be increased by about 10 kilograms, and each vehicle can increase production by about 6 tons per month.
(7) The efficiency of roving operation is improved. According to statistics, the original monthly maintenance time of the Tiegun roving frame was about 30 hours, resulting in a monthly output loss of 2.1 tons. After the transformation, there were basically no faults, which is equivalent to an increase in output of 25 tons per year.
(8) The number of broken yarns and roving ends is reduced. It is estimated that after the transformation, about 800 yuan can be saved every month.
(9) The large external electric cabinet has a large internal space and is equipped with an axial flow fan for fast air circulation and good cooling effect, fully ensuring the stability of the operation of electrical components.
(10) It has a power-off protection function, which can ensure that the tension fluctuates relatively stably when a sudden power outage or voltage abnormality occurs in the external power grid.� Small, avoiding details or broken ends on the entire machine.
(11) Functions such as status query and fault query have been added. The controller and input and output points can be queried, and faults can be analyzed based on the data of each input point.
4. Conclusion
The four-motor intelligent transformation of the mechanical transmission roving frame has greatly simplified the mechanical transmission structure, effectively reduced the mechanical failure rate, improved yarn quality, increased spindle speed, and increased output. The transformed roving frame has reached the same level as The original computerized roving frame has the same usage requirements and quality standards, and maintenance workers and on-duty lathes generally report very good results.
</p
