A pre-tensioning device and control method for a winding machine

Abstract

This invention relates to the field of yarn tension control technology for winding machines, providing a pre-tensioning device and control method for winding machines, aiming to solve the quality problems caused by tension fluctuations in high-twist yarns during the winding process. The pre-tensioning device includes a fixed frame, a movable frame, a torque spring, an adjusting nut, and a plastic bearing. Rotating the adjusting nut changes the preload of the torque spring on the movable frame, thereby adjusting the output tension. The device utilizes the resilience of the torque spring to buffer and compensate for yarn tension fluctuations, reducing yarn vibration and lowering the probability of yarn kinking, webbing, and bobbin defects. The control method includes steps such as yarn preparation, yarn insertion, tension application, winding, yarn detection, and cutting, ensuring stable yarn tension and improving bobbin quality. This invention has a simple structure, low cost, is easy to install and maintain, and is suitable for various yarn types and process requirements.

Description

Technical Field

[0001] This invention relates to the field of yarn tension control technology for winding machines, and specifically to a pre-tensioning device for winding machines. Background Technology

[0002] In the textile industry, high-twist yarns are more likely to experience yarn twisting, web formation, and coil defects during the winding process, significantly impacting yarn quality. These defects are primarily related to tension fluctuations during high-speed winding or twisting cycles. Therefore, better controlling and stabilizing tension during high-speed winding and twisting cycles is crucial for eliminating yarn twisting, web formation, and coil defects. High-twist yarns generally refer to medium-high count yarns with ultra-high twist or low count yarns with normal twist. Due to their high twist coefficient, the fiber aggregates generate a greater counterforce against the twisting force, which is called untwisting force. This internal stress in the yarn can cause a section of unwound yarn to form a knot when the tension is insufficient. This often occurs during the splicing cycle and also during high-speed winding. The direction of the yarn untwisting force is along the cross-section of the yarn. During high-speed winding, the yarn is in a straightened state and has a certain tension. The tension direction is along the yarn axis. Therefore, when the internal stress (cross-sectional direction) generated by the untwisting tendency of the yarn is large enough, it will affect the winding tension (yarn axis), causing tension fluctuations. The yarn will vibrate in the cross-sectional direction when it is straightened, increasing the probability of the yarn forming a net and forming a tangled yarn. Tension fluctuations caused by yarn untwisting stress during high-speed winding have the following characteristics: frequent, rapid, and unpredictable. Therefore, even tension sensors with tension closed-loop functions cannot guarantee timely and accurate judgments to ensure that the tension output device outputs tension accurately in real time. Ultimately, the winding tension fluctuations cause yarn vibration, and problems such as yarn weaving and yarn sticking occur in the yarn package.

[0003] Patent No. CN 108217336 A describes a linear yarn pressurization device that uses electromagnetic pressurization with grid-type ceramic plates to pressurize the yarn. Different voltage values ​​achieve different tension outputs. However, when the yarn experiences rapid, irregular, and short-duration tension changes, it cannot provide accurate tension compensation in real time. CN 101920872 B describes a winding machine tension control device that uses electromagnetic pressurization with a pair of metal discs to pressurize the yarn. The metal discs rotate at a certain speed, but tension instability occurs during rotation, and timely and accurate tension compensation cannot be provided. CN 105819275 B describes a device that uses electromagnetic pressurization with a pair of ceramic discs to pressurize the yarn, overcoming the tension instability problem during rotation, but still cannot provide accurate and real-time tension compensation. CN 103359541 B describes a tensioning device that uses a linear spring to apply pressure to the yarn via a fixed and a movable directional switch. The linear spring can achieve more real-time and accurate tension compensation for rapid and irregular tension fluctuations, controlling tension fluctuations and reducing yarn vibration. The device's opening and closing power source is a stepper motor, which adds extra cost. EP 1.975.105A2 describes a coil tensioning device with spring pressure, which can effectively control tension above 0.2-0.3N, but below this tension, the coil tensioning device is not accurate enough and is not very reliable. Similarly, EP734.990B1 also describes a coil tensioning device with a magnetic coil, with the same problems as EP1.975.105A2. CN101759062B introduces a winding machine with two tension control mechanisms. The first tension device is used to control the tension between the unwinding of the bobbin and the yarn accumulator, and the second tension device is used to control the tension between the yarn accumulator and the bobbin. For conventional winding machines without accumulators, it is difficult to achieve this tension control or the cost is too high.

[0004] In summary, existing yarn tension control devices have significant shortcomings in addressing tension fluctuations during high-speed winding, including issues with control accuracy, real-time compensation capabilities, operational complexity, and cost. These problems directly impact yarn quality and production efficiency. Summary of the Invention

[0005] To address the problems existing in the background art, the present invention provides a pre-tensioning device for a winding machine, which includes a lower scissor bracket installed on the winding machine, and a device body installed below the scissor bracket. The device body includes a fixed frame, a movable frame, a torque spring, an adjusting nut, and a plastic bearing, wherein:

[0006] The fixed frame is fixed on the lower scissor bracket. The fixed frame is equipped with guide posts and metal support columns. The adjusting nut is rotated and sleeved on the guide posts of the fixed frame. The upper part of the adjusting nut is provided with a limit hole, and the upper end of the torque spring is connected to the limit hole. By rotating the adjusting nut, the preload of the torque spring on the movable frame is changed, thereby adjusting the tension output by the device.

[0007] The plastic bearing is fitted onto the metal support, and the torque spring is fitted onto the outside of the plastic bearing. The lower end of the torque spring presses against the movable frame, while the upper end is fixed by an adjusting nut.

[0008] The movable frame is also fitted onto the plastic bearing and is subjected to the thrust of the torque spring; when the torque spring is compressed or stretched, the torque spring applies or releases tension on the yarn through the movable frame.

[0009] In a preferred embodiment, a limiting stud is also included, which is fixed to the fixed frame by a limiting nut to limit the movement angle of the movable frame.

[0010] In the preferred embodiment, both the fixed frame and the movable frame are equipped with yarn-guiding ceramics to guide the yarn smoothly through the pre-tensioning device and reduce friction between the yarn and the metal parts.

[0011] In the preferred embodiment, the fixing frame is fixed to the lower yarn scissor bracket by two screws.

[0012] In the preferred embodiment, a yarn guide ceramic ring is installed below the scissor bracket.

[0013] A method for controlling yarn winding tension in a winding machine, comprising the following steps:

[0014] S1. Winding preparation:

[0015] Before the winding begins, the lever mechanism is activated, putting the scissors in the closed cutting state and the pre-cleaning device in the open state. At this time, the movable frame of the pre-tensioning device is also opened by the lever mechanism until the yarn is fed into the pre-tensioning device. Then, the lever mechanism resets, the scissors open, the pre-cleaning device closes, and the pre-tensioning device closes, allowing the yarn to be inserted smoothly. The yarn is guided to the entrance of the pre-tensioning device, ready to enter the channel formed by the fixed frame and the movable frame.

[0016] S2, Yarn insertion:

[0017] The movable frame of the pretensioning device begins to close; the yarn is placed into the pretensioning device and passes through the yarn guide ceramic between the fixed frame and the movable frame;

[0018] S3, Tension Application:

[0019] During this process, the torque spring applies a stable thrust to the movable frame, and in conjunction with the fixed frame, applies additional tension to the yarn;

[0020] S4, winding yarn:

[0021] The winding machine performs the winding action. During the winding process, the yarn continuously passes through the pre-tensioning device. If the yarn tension fluctuates, the torque spring uses its elasticity to buffer and compensate for the tension fluctuation. When the yarn tension tends to stabilize, the movable frame of the pre-tensioning device also remains stable, and the output additional tension remains unchanged.

[0022] S5. Yarn Inspection and Cutting:

[0023] During the winding process, if an unacceptable defect is detected in the yarn, the yarn is quickly cut off by the electronic yarn clearer to prevent the defect from entering the yarn package; at this time, the pre-tensioning device continues to maintain its tension output state, waiting for the insertion of the next yarn and the start of the winding process;

[0024] In the preferred embodiment, step S1 further includes adjusting the tension output by the pretensioning device by rotating the adjusting nut to change the preload of the torque spring according to the yarn type or process requirements.

[0025] The preferred solution also includes step S6, maintenance and adjustment, the specific process of which is as follows: after the winding is completed, the pre-tensioning device is inspected, cleaned or adjusted, and the wear of the yarn guide ceramic is checked. Maintenance or replacement is performed according to the wear condition.

[0026] The beneficial effects achieved by this invention are as follows:

[0027] First, this invention provides a pre-tensioning device with a simple structure and convenient use. It requires no additional power source to control the opening and closing of the device, resulting in lower costs. After adding this device, the single spindle maintains its original disc tension. The additional tension required for winding is mainly output from the original disc tension. The pre-tensioning device, relying on a torque spring, provides only a small portion of the additional tension to control yarn tension fluctuations and reduce yarn vibration. The tension output of this device can be adjusted according to actual conditions. Therefore, all winding tensions include the unwinding tension of the bobbin, the tension generated by friction, the output tension of the disc device, and the output tension of the pre-tensioning device.

[0028] Secondly, the pre-tensioning device is installed below the lower scissor bracket of the single spindle on the winding machine. Utilizing the single spindle lower scissor opening lever mechanism, it opens when the device needs to be opened to insert yarn and closes before the single spindle starts to provide additional tension. It relies on the thrust of a torque spring applied to the yarn guide ceramic of the movable frame, cooperating with the yarn guide ceramic of the fixed frame to apply additional tension to the wound yarn. The torque provided by the torque spring can be adjusted to suit different yarn types. When the yarn tension remains stable, the movable frame of the pre-tensioning device remains stable, and the output tension remains constant. When the yarn tension fluctuates, this fluctuation may originate from yarn unwinding, friction, yarn internal stress, or the disc device; changes in one or more factors cause tension instability. Since the device itself lacks rapid and accurate tension compensation, the torque spring of the pre-tensioning device has its own resilience, providing good buffering for tension fluctuation pulses. After the yarn tension stabilizes, the movable frame of the pre-tensioning device also stabilizes, returning to a stable tension output position, maintaining a stable output of additional tension. The function of the pre-tensioning device is to utilize the torsional characteristics of the torsion spring to buffer the tension fluctuations generated during the winding process, such as yarn unwinding, friction, yarn internal stress, or the tension fluctuations generated by the disc device, and to provide tension compensation to reduce tension fluctuations, reduce yarn vibration, and reduce the probability of high-twist yarn kinking, yarn twisting, and bobbin defects.

[0029] Third, the pre-tensioning device and control method for a winding machine provided by this invention can buffer and compensate for yarn tension fluctuation pulses, reducing yarn tangling, yarn weaving, and yarn breakage. It is simple to use, low in cost, and highly effective. It requires no additional power components such as stepper motors, cylinders, or solenoid valves; the device opens and closes using the opening rod mechanism of the single spindle itself. A torque spring is used to control the yarn tension on the movable frame of the device, providing rapid and accurate buffering and compensation, and assisting the disc-type device in achieving more stable winding tension control. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the pretensioning device.

[0031] Figure 2 This is a schematic diagram of yarn untwisting force;

[0032] Figure 3 This is a schematic diagram of the pretensioning device and the opening rod mechanism;

[0033] Figure 4 This is a schematic diagram of yarn tension.

[0034] Figure 5 This is a schematic diagram of the single-spindle structure of the winding machine in Example 1;

[0035] Figure 6 This is a schematic diagram of the single-spindle winding process in Example 1.

[0036] Numbering on the map:

[0037] 1. Lower scissor bracket; 2. Fixed frame; 3. Movable frame; 4. Torque spring; 5. Adjusting nut; 6. Plastic bearing; 7. Limiting stud; 8. Ceramic guide ring; 9. Metal pressure plate; 10. Ceramic guide; 11. Metal support; 12. Retaining ring; 13. Flat washer; 14. Screw; 15. Limiting nut; 16. Pre-tensioning device; 17. Disc device; 18. Unwinding tension of bobbin; 19. Tension generated at each friction point; 20. Internal stress of yarn untwisting; 21. Yarn cone; 22. Yarn cone cradle; 23. Grooved bobbin; 24. Electronic yarn clearer; 25. Splicer; 26. Yarn cone suction nozzle; 27. Main housing; 28. Yarn feeding rod; 29. ​​Lower scissor; 30. Pre-cleaning device; 31. Yarn cone suction nozzle; 32. Yarn guide; 33. Yarn cone; 34. Yarn; 35. Single spindle; 36. Opening rod mechanism. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. In addition, the forms of the various structures described in the following embodiments are merely illustrative. The present invention is not limited to the structures described in the following embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] Reference Figures 1-5 The present invention provides a pre-tensioning device 16 for a winding machine, comprising a lower scissor bracket 1 installed on the winding machine, and a device body installed below the scissor bracket. The device body includes a fixed frame 2, a movable frame 3, a torque spring 4, an adjusting nut 5, and a plastic bearing 6. The fixed frame 2 is fixed on the lower scissor bracket 1 and is provided with a guide post and a metal support post 11. The adjusting nut 5 is rotatably sleeved on the guide post of the fixed frame 2. A limit hole is provided on the upper part of the adjusting nut 5, and the upper end of the torque spring 4 is connected to the limit hole. By rotating the adjusting nut 5, the pre-tension force of the torque spring 4 on the movable frame 3 is changed, thereby adjusting the tension output by the device. The plastic bearing 6 is sleeved on the metal support post 11, and the torque spring 4 is sleeved on the outside of the plastic bearing 6. The lower end of the torque spring 4 presses against the movable frame 3, and the upper end is fixed by the adjusting nut 5.

[0040] The movable frame 3 is also fitted onto the plastic bearing 6 and is subjected to the thrust of the torque spring 4. When the torque spring 4 is compressed or stretched, it applies or releases tension on the yarn 34 through the movable frame 3. It also includes a limiting component, which consists of a limiting stud 7 and a limiting nut 15. The limiting stud 7 is fixed to the fixed frame 2 by the limiting nut 15, and works together with the flat washer 13 to limit the movement angle of the movable frame 3.

[0041] Both the fixed frame 2 and the movable frame 3 are equipped with yarn-guiding ceramics 10 to guide the yarn 34 smoothly through the pre-tensioning device 16 and reduce friction between the yarn 34 and the metal parts. The fixed frame 2 is fixed to the lower yarn scissor bracket by two screws 14. A yarn-guiding ceramic ring 8 is installed below the scissor bracket.

[0042] The present invention provides a method for controlling the winding tension of a winding machine, which is carried out according to the following steps:

[0043] S1. Winding preparation:

[0044] Before the winding begins, the opening lever mechanism 36 is activated, causing the scissors 29 to be in the closed cutting state and the pre-cleaning device 30 to be in the open state. At this time, the movable frame 3 of the pre-tensioning device 16 is in the open state under the action of the opening lever mechanism 36 until the yarn is fed into the pre-tensioning device 16. Then, the opening lever mechanism 36 is reset, the scissors 29 is opened, the pre-cleaning device 30 is closed, and the pre-tensioning device 16 is closed, allowing the yarn 34 to be smoothly inserted. The yarn 34 is guided to the entrance of the pre-tensioning device 16, ready to enter the channel formed by the fixed frame 2 and the movable frame 3.

[0045] S2, Yarn 34 insertion:

[0046] The movable frame 3 of the pretensioning device 16 begins to close; the yarn 34 is placed into the pretensioning device 16 and passes through the yarn guide ceramic 10 between the fixed frame 2 and the movable frame 3;

[0047] S3, Tension Application:

[0048] During this process, the torque spring 4 applies a stable thrust to the movable frame 3, and cooperates with the fixed frame 2 to apply additional tension to the yarn 34;

[0049] S4, winding yarn:

[0050] The winding machine performs the winding action. During the winding process, the yarn 34 continuously passes through the pre-tension device 16. If the tension of the yarn 34 fluctuates, the torque spring 4 uses its elasticity to buffer and compensate for the tension fluctuation. When the tension of the yarn 34 tends to stabilize, the movable frame 3 of the pre-tension device 16 also remains stable, and the output additional tension remains unchanged.

[0051] S5, Yarn 34 Inspection and Cutting:

[0052] During the winding process, if an unacceptable defect is detected in the yarn 34, the yarn 34 is quickly cut off by the electronic yarn clearer 24 to prevent the defect from entering the yarn package 21; at this time, the pre-tension device 16 continues to maintain its tension output state, waiting for the insertion of the next yarn 34 and the start of the winding process.

[0053] Step S1 also includes adjusting the tension output by the pretensioning device 16 by rotating the adjusting nut 5 to change the preload of the torque spring 4 according to the type of yarn 34 or process requirements.

[0054] It also includes step S6, maintenance and adjustment, the specific process is as follows: after the winding is completed, the pre-tension device 16 is inspected, cleaned or adjusted, and the wear of the yarn guide ceramic 10 is checked, and maintenance or replacement is carried out according to the wear.

[0055] Example 1: In this embodiment, the spindle is first explained. In the field of textile machinery, especially in automatic winding machines, a single spindle 35 refers to an independent working unit on the winding machine. Each single spindle 35 can independently complete the winding process of yarn 34, including yarn introduction, tension control, and winding into a bobbin. In automatic winding machines, multiple single spindles 35 usually work in parallel to improve production efficiency and output.

[0056] In this embodiment, each spindle 35 is an independent winding unit, capable of independently completing the entire process from yarn 34 introduction, tension adjustment to winding into a bobbin. Each spindle 35 is equipped with a tension control device, such as a disc tension device and a pre-tension device 16, to control the tension of the yarn 34 during the winding process, ensuring the tightness and uniformity of the yarn winding. An automatic winding machine typically has multiple spindles 35, which can work in parallel, simultaneously winding multiple yarns 34, thereby significantly improving overall production efficiency.

[0057] In this embodiment, 24-count 1450-twist / meter high-twist yarn is used. The pre-tensioning device 16 is installed below the disc-type tensioning device 17 of the single spindle 35 structure of the winding machine and is fixed to the main housing 27 by the lower scissor bracket 11. The opening and closing of the movable frame 3 of the pre-tensioning device 16 shares the opening rod mechanism 36 of the lower scissor 29 / pre-cleaning yarn 30. The opening angle of the movable frame 3 is between 20° and 40°, which facilitates the insertion of the yarn 34.

[0058] The distance between the centers of the upper and lower ceramic parts of the movable frame 3 should be 18-22mm. The torque spring 4 is a left-handed spring with 20 effective turns and a certain torque. In this embodiment, the adjusting nut 5 is a regular hexagon with no internal threads, and one corner has a through hole with a diameter of 0.7-1mm. The plastic bearing 6 has a self-lubricating function. The length of the limiting stud 7 is between 16-20mm. The surface roughness Ra of the yarn guiding ceramic 10 should be between 0.3-0.4.

[0059] The metal support 11 has a special protrusion in the middle, which separates the upper adjusting nut 5 and the lower plastic bearing 6, and restricts the adjusting nut 5 from moving axially along the metal support 11. The pretensioning device 16 should be aligned with the yarn path, ensuring that the yarn guide point of the pretensioning device 16 coincides with the yarn path in four directions: front, back, left, and right. To ensure consistent winding tension, after installing the pretensioning device 16, the tension output of the disc device 17 should be appropriately reduced by 10%-15%.

[0060] like Figure 5 As shown, when the single spindle 35 starts, the yarn end of the bobbin 33 is blown by air to the top of the yarn feeder 32. The bobbin suction nozzle 31 captures the yarn 34, the disc device 17 opens, the opening lever mechanism 36 operates, the pre-tension device 16, the disc device 17, and the pre-cleaning device 30 open, and the lower scissors 29 close to cut the yarn. The bobbin suction nozzle 26 approaches the bobbin 21 fixed on the bobbin cradle 22, the grooved cylinder 23 rotates in the opposite direction, the bobbin suction nozzle 26 captures the yarn end, pulls the yarn 34 downward and feeds it into the splicer 25, the bobbin suction nozzle 31 pulls the yarn 34 upward, the yarn feeder 28 swings to feed the yarn 34 into the splicer 25, the disc device 17 closes, the opening lever mechanism 36 operates, the pre-tension device 16 and the pre-cleaning device 30 close, and the lower scissors 29 open. At this time, the yarn 34 has been simultaneously placed into the pre-cleaning device 30, the pre-tension device 16, and the disc device 17. The splicer 25 completes the joining of yarn 34, and the spindle 35 starts winding. When an unacceptable defect is detected in yarn 34, the electronic yarn clearer 24 cuts the yarn 34 and enters the next cycle.

[0061] The pretension can be adjusted in multiple levels using adjusting nut 5. The pretension device 16 can be adjusted according to the actual yarn type (34). Generally, the lower the yarn count, the higher the tension output of the pretension device 16 should be, and the higher the yarn count, the lower the tension output should be. Figure 3 The diagram illustrates the sources of tension in yarn 34. These include unwinding tension 18, tension 19 generated at various friction points, yarn untwisting internal stress 20, additional tension provided by disc device 17, and extra additional tension provided by pre-tensioning device 16.

[0062] Before and after installing the pre-tensioning device 16, the good rate of the yarn package 21 increased from 90%-95% to 99%-99.5%, the yarn 34 inside the package was free of kinks, and there was no mesh on the end face of the yarn package 21. The production efficiency increased by 3%-5%, the output increased by 2%-4%, and the number of broken ends per million meters in the next warping process decreased from 0.8-1.2 to 0.4-0.5.

[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A pre-tensioning device for a winding machine, characterized in that, It includes a lower scissor bracket installed on a winding machine, with a main body of the device installed below the scissor bracket. The main body of the device includes a fixed frame, a movable frame, a torque spring, an adjusting nut, and a plastic bearing, wherein: The fixed frame is fixed on the lower scissor bracket. The fixed frame is equipped with guide posts and metal support columns. The adjusting nut is rotated and sleeved on the guide posts of the fixed frame. The upper part of the adjusting nut is provided with a limit hole, and the upper end of the torque spring is connected to the limit hole. By rotating the adjusting nut, the preload of the torque spring on the movable frame is changed, thereby adjusting the tension output by the device. The plastic bearing is fitted onto the metal support, and the torque spring is fitted onto the outside of the plastic bearing. The lower end of the torque spring presses against the movable frame, while the upper end is fixed by an adjusting nut. The movable frame is also fitted onto the plastic bearing and is subjected to the thrust of the torque spring; when the torque spring is compressed or stretched, the torque spring applies or releases tension on the yarn through the movable frame.

2. The pre-tensioning device for a winding machine according to claim 1, characterized in that, It also includes a limit stud, which is fixed to the fixed frame by a limit nut to limit the movement angle of the movable frame.

3. The pre-tensioning device for a winding machine according to claim 1, characterized in that: Both the fixed and movable frames are equipped with yarn-guiding ceramics to guide the yarn smoothly through the pre-tensioning device and reduce friction between the yarn and the metal parts.

4. The pre-tensioning device for a winding machine according to claim 1, characterized in that: The fixing bracket is fixed to the lower yarn scissor bracket by two screws.

5. The pre-tensioning device for a winding machine according to claim 1, characterized in that: A yarn guide ceramic ring is installed below the scissor bracket.

6. A method for controlling the winding tension of a winding machine, characterized in that, It employs the pre-tensioning device for the winding machine as described in any one of the claims, and proceeds according to the following steps: S1. Winding preparation: Before the winding begins, the lever mechanism is activated, putting the scissors in the closed cutting state and the pre-cleaning device in the open state. At this time, the movable frame of the pre-tensioning device is also opened by the lever mechanism until the yarn is fed into the pre-tensioning device. Then, the lever mechanism resets, the scissors open, the pre-cleaning device closes, and the pre-tensioning device closes, allowing the yarn to be inserted smoothly. The yarn is guided to the entrance of the pre-tensioning device, ready to enter the channel formed by the fixed frame and the movable frame. S2, Yarn insertion: The movable frame of the pretensioning device begins to close; the yarn is placed into the pretensioning device and passes through the yarn guide ceramic between the fixed frame and the movable frame; S3, Tension Application: During this process, the torque spring applies a stable thrust to the movable frame, which, in conjunction with the fixed frame, applies additional tension to the yarn; S4, winding yarn: The winding machine performs the winding action, during which the yarn continuously passes through the pre-tensioning device; If the yarn tension fluctuates, the torque spring uses its resilience to buffer and compensate for the tension fluctuation; when the yarn tension tends to stabilize, the movable frame of the pretensioning device also remains stable, and the output additional tension remains unchanged. S5. Yarn Inspection and Cutting: During the winding process, if an unacceptable defect is detected in the yarn, the yarn is quickly cut off by an electronic yarn clearer to prevent the defect from entering the yarn package. At this time, the pre-tensioning device continues to maintain its tension output state, waiting for the insertion of the next yarn and the start of the winding process.

7. The method for controlling yarn tension on a winding machine according to claim 6, characterized in that, Step S1 also includes adjusting the tension output by the pretensioning device by rotating the adjusting nut to change the preload of the torque spring, according to the yarn type or process requirements.

8. The method for controlling the winding tension of a winding machine according to claim 6, characterized in that, It also includes step S6, maintenance and adjustment, the specific process is as follows: After the winding is completed, the pre-tensioning device is inspected, cleaned or adjusted, and the wear of the yarn guide ceramic is checked. Maintenance or replacement is carried out according to the wear condition.

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