Yarn tension adjusting device of circular knitting machine

Abstract

The invention discloses a yarn tension adjusting device of a circular knitting machine, which relates to the field of textile machinery and comprises an arc-shaped mounting plate of a circular structure; the plurality of wire passing devices are uniformly distributed on the outer ring of the arc-shaped mounting plate; the grid plate is arranged at the bottom of the arc-shaped mounting plate; the central control device is arranged at the top of the arc-shaped mounting plate; the wire passing device comprises a base which is fixedly mounted on the outer wall of the arc-shaped mounting plate; and a first wire passing plate and a second wire passing plate. By arranging the shear type structure composed of the first shear rod and the second shear rod which are driven by the pressure floating adjusting device and cooperating with the Y-shaped floating supporting base and the yarn passing wheels at the two ends of the Y-shaped floating supporting base, triangular stable supporting of a yarn path is achieved, the wrap angle adjusting range of yarn and the yarn passing wheels is remarkably enlarged, and the yarn passing wheels can be adjusted more stably. And the sensitivity and the response speed of tension adjustment are greatly improved through the amplification effect of the shear type structure.

Description

Technical Field

[0001] This invention relates to the field of textile machinery, specifically to a yarn tension adjustment device for a circular knitting machine. Background Technology

[0002] Circular knitting machines are widely used in the textile industry, primarily for producing various knitted fabrics. During operation, the stability of yarn tension directly affects fabric quality and production efficiency. Excessive yarn tension can lead to yarn breakage or fabric shrinkage; insufficient tension can result in loose yarn and uneven fabric density. Therefore, a yarn tension regulating device is an indispensable key component of a circular knitting machine, used to monitor and adjust yarn tension in real time during transport, ensuring it remains constant and suitable.

[0003] In existing technologies, yarn tension regulating devices typically include multiple guide rollers, a tension sensor, and an adjusting mechanism. The yarn passes sequentially through these guide rollers, and the yarn tension is adjusted by changing the position of the rollers or applying damping force. Some devices employ a floating roller structure, using springs or pneumatic components to apply pressure to the floating roller, thereby regulating the yarn tension. Additionally, some devices use a motor-driven sliding block to change the contact angle or path length between the yarn and the guide rollers to achieve tension regulation. The sensor is used to monitor the yarn tension in real time and feed the data back to the controller, forming a closed-loop control system.

[0004] However, existing yarn tension regulating devices still have certain shortcomings. First, traditional devices often employ a single adjustment method, such as simply changing the position of the yarn guide wheel or applying pressure solely through a spring. This results in limited adjustment precision and makes it difficult to handle rapid fluctuations in yarn tension. Second, the floating roller structure has limitations in response speed and adjustment range, especially under high-speed operating conditions, where adjustment lag is quite noticeable. Furthermore, existing devices are structurally complex, inconvenient to maintain, and make it difficult to achieve independent control of tension adjustment among multiple yarns, affecting overall weaving quality and efficiency. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide a yarn tension adjustment device for a circular knitting machine, so as to solve the technical problems of slow yarn tension adjustment response speed, low control accuracy and inability to take into account both rapid coarse adjustment and fine fine adjustment in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a yarn tension adjustment device for a circular knitting machine, comprising: an arc-shaped mounting plate with a circular structure; a plurality of yarn guide devices evenly distributed around the outer ring of the arc-shaped mounting plate; a grid plate disposed at the bottom of the arc-shaped mounting plate; and a central control device disposed at the top of the arc-shaped mounting plate; the yarn guide devices comprising: a base fixedly mounted on the outer wall of the arc-shaped mounting plate; a first yarn guide plate and a second yarn guide plate respectively inclinedly disposed at the top and bottom ends of the base, the first yarn guide plate having a yarn inlet and the second yarn guide plate having a yarn outlet; a movable seat slidably disposed on the base; a driving mechanism disposed on the base for driving the movable seat to slide along the base; and a floating support mechanism comprising a rotatably disposed on... The movable base includes a Y-shaped floating support seat and thread guide wheels at both ends of the Y-shaped floating support seat; a pressure floating adjustment device is mounted on the movable base, with its output end connected to a first shear rod; a second shear rod has one end rotatably connected to the Y-shaped floating support seat and the other end slidably engaged with the movable base; the middle sections of the first and second shear rods are rotatably connected to form a scissor structure; the pressure floating adjustment device is used to drive the first shear rod to move, thereby adjusting the angle of the Y-shaped floating support seat; a yarn inlet tension sensor and a yarn outlet tension sensor are respectively mounted on the base near the first and second thread guide plates, for detecting yarn tension; the yarn inlet tension sensor, the yarn outlet tension sensor, and the drive mechanism are all electrically connected to the central control device.

[0007] The present invention is further configured such that the driving mechanism includes: a fixed plate disposed on the base near the yarn inlet; a driving motor disposed on the base near the fixed plate; and a threaded rod connected to the output end of the driving motor and passing through the movable seat for driving the movable seat to reciprocate along the base.

[0008] The present invention is further configured such that the floating support mechanism includes: a limiting plate disposed on the movable seat; and a pin that passes through the limiting plate and one end of the Y-shaped floating support, so that the Y-shaped floating support is rotatably connected to the movable seat.

[0009] The present invention is further configured such that the movable seat is provided with a guide groove, and the end of the second shear bar is slidably disposed in the guide groove; An angle sensor is provided at the intersection of the first and second scissor bars to monitor their rotation angle. The angle sensor is electrically connected to the central control device.

[0010] The present invention is further configured such that the pressure floating adjustment device includes: a piston chamber filled with magnetorheological fluid; a push plate slidably disposed in the piston chamber; a push rod, one end of which is connected to the push plate and the other end of which extends to the outside of the piston chamber; a connector disposed at the end of the push rod and rotatably connected to one end of the first shear rod; and a magnetic control coil wound around the outside of the piston chamber and electrically connected to the central control device.

[0011] The invention is further configured such that a return spring is provided inside the piston chamber, and the return spring is located on the side of the push plate away from the push rod.

[0012] In summary, the present invention has the following main beneficial effects: This invention, through the use of a scissor structure consisting of a first and a second scissor rod driven by a pressure floating adjustment device, and in conjunction with a Y-shaped floating support seat and its two end guide rollers, not only achieves triangular stable support for the yarn path, significantly increasing the adjustment range of the wrap angle between the yarn and the guide rollers, but also greatly improves the sensitivity and response speed of tension adjustment through the amplification effect of the scissor structure. Simultaneously, the driving mechanism consisting of a drive motor and a threaded rod drives the sliding seat, enabling rapid changes in the overall position of the floating support seat for coarse adjustment of yarn tension, while the pressure floating adjustment device finely adjusts the angle of the floating support seat through the scissor structure. The two work together to achieve both rapid response and high-precision control of tension adjustment. Furthermore, through… By using an angle sensor to monitor the intersection angle of the first and second shear bars in real time, and combining this with the yarn tension sensors for dynamic monitoring of the yarn tension, the central control device can achieve closed-loop precise control based on multiple feedback signals, significantly improving the stability and reliability of tension adjustment. Furthermore, the pressure floating adjustment device adopts a structure that combines magnetorheological fluid with a magnetic control coil. By adjusting the magnetic field strength, the damping force in the piston chamber can be quickly changed, thereby controlling the movement of the push rod. The structure is compact and the response is rapid, further improving the adjustment accuracy and dynamic response performance. It effectively overcomes the problems of single adjustment method, slow response, and insufficient control accuracy in existing technologies, and can meet the stringent requirements for tension stability in high-quality fabric production. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the wire guiding device of the present invention; Figure 3 This is a schematic diagram of the wire guiding device of the present invention; Figure 4 This is a schematic diagram of the pressure floating adjustment device of the present invention; Figure 5 This is a schematic diagram of the internal structure of the pressure floating adjustment device of the present invention; Figure 6 This is a schematic diagram of the internal structure of the piston cavity of the present invention; Figure 7 This is a schematic diagram of the piston cavity structure of the present invention.

[0014] In the diagram: 1. Arc-shaped mounting plate; 2. Yarn guide device; 3. Grid plate; 4. Central control device; 5. First yarn guide plate; 6. Yarn inlet tension sensor; 7. Fixing plate; 8. Yarn outlet tension sensor; 9. Pressure floating adjustment device; 10. First shear bar; 11. Floating support seat; 12. Yarn guide wheel; 13. Limiting plate; 14. Pin shaft; 15. Drive motor; 16. Yarn outlet; 17. Second yarn guide plate; 18. Connector; 19. Push rod; 20. Magnetic control coil; 21. Push plate; 22. Piston chamber; 23. Return spring; 24. Base; 25. Angle sensor; 26. Second shear bar; 27. Guide groove; 28. Threaded rod; 29. ​​Support plate. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0016] The embodiments of the present invention will now be described.

[0017] A yarn tension adjustment device for a circular knitting machine, such as Figure 1-7 As shown, the device includes a circular arc-shaped mounting plate 1, which serves as the mounting base for the entire device. Its curvature matches the circular outline of the circular knitting machine, facilitating installation on the machine's periphery. A grid plate 3 is fixedly installed at the bottom of the arc-shaped mounting plate 1, which can be used for wiring or mounting electrical components. A central control device 4 is fixedly installed at the top of the arc-shaped mounting plate 1. This central control device 4 can be a PLC controller or a microcontroller control system, used to receive signals from various sensors and issue control commands. Several yarn guide devices 2 are evenly distributed around the outer circumference of the arc-shaped mounting plate 1. After the yarn is introduced from the outside, it passes through these yarn guide devices 2 for tension adjustment before being output to the knitting area of ​​the circular knitting machine. Each yarn guide device 2 has an identical structure and is used to independently adjust the tension of one yarn path. Through the coordinated work of multiple yarn guide devices 2, unified control of multiple yarn paths is achieved.

[0018] Combination Figure 1 and Figure 2As shown, each yarn guiding device 2 includes a base 29, one side of which is fixed to the outer wall of the arc-shaped mounting plate 1 by bolts or welding. The base 29 has a plate-like structure, with a first yarn guiding plate 5 inclined at a certain angle at its top (i.e., the upstream end along the yarn travel direction), and a second yarn guiding plate 17 inclined at a certain angle at its bottom (i.e., the downstream end). The first yarn guiding plate 5 has a yarn inlet 24, and the second yarn guiding plate 17 has a yarn outlet 16. The yarn is first introduced into the yarn inlet 24 from the outside, and after passing through the adjustment path inside the device, it is led out from the yarn outlet 16 to the next process. This inclined yarn guiding plate helps to guide the yarn smoothly in and out.

[0019] On the side of the base 29 away from the arc-shaped mounting plate 1, a movable seat 30 is slidably mounted. To achieve the sliding of the movable seat 30, a slide rail can be provided on the base 29, and a slide groove can be provided on the movable seat 30, with the two slidingly engaged. A drive motor 15 and a fixing plate 7 are respectively provided on both sides of the yarn inlet 24 on the base 29, and both the drive motor 15 and the fixing plate 7 are fixedly mounted on the base 29. A threaded rod 28 is connected to the output end of the drive motor 15. The threaded rod 28 passes through the movable seat 30 and is threadedly engaged with a threaded hole on the movable seat 30. When the drive motor 15 receives a command from the central control device 4 and starts, its output shaft drives the threaded rod 28 to rotate. Due to the rotation of the threaded rod 28, the movable seat 30, which is threadedly engaged with it, will move along the length direction of the base 29 (i.e., the direction perpendicular to the paper plane or...). Figure 2 The moving seat 30 moves back and forth in a linear motion (left and right directions). By controlling the rotation direction and number of rotations of the drive motor 15, the displacement and direction of the moving seat 30 can be precisely controlled. This is one of the actuators for rapid and wide-range adjustment (coarse adjustment) of yarn tension.

[0020] Please continue reading. Figure 3A floating support mechanism is provided on the side of the movable seat 30 away from the base 29. Specifically, a limiting plate 13 is fixedly provided on the movable seat 30. The limiting plates 13 are usually arranged in pairs with a gap between them. A Y-shaped floating support seat 11 is provided between the limiting plates 13. The floating support seat 11 has an overall Y-shaped structure, and its single end (i.e., the handle of the Y-shape) is inserted into the gap between the two limiting plates 13. A pin 14 passes through both the limiting plate 13 and the single end of the floating support seat 11, so that the floating support seat 11 can rotate relative to the movable seat 30 with the pin 14 as the rotation center. Wire guide wheels 12 are respectively provided at the other two ends of the floating support seat 11 (i.e., the two branches of the Y-shape), and the two wire guide wheels 12 can rotate freely. This Y-shaped structure design allows a stable triangular support structure to be formed when the yarn passes between the two guide rollers 12, ensuring smooth yarn operation. At the same time, by changing the rotation angle of the floating support seat 11, the contact wrap angle between the yarn and the guide rollers 12 can be changed, thereby finely adjusting the yarn tension.

[0021] Based on the above structure, a pressure floating adjustment device 9 is fixedly installed on one side of the floating support 11 on the movable base 30. This pressure floating adjustment device 9 is the core fine-tuning actuator of the present invention. The output end of the pressure floating adjustment device 9 (specifically the connector 18, which will be described in detail later) is rotatably connected to one end of the first shear bar 10. The other end of the first shear bar 10 is rotatably connected to a fixed point on the movable base 30, or suspended in the air. One end of the second shear bar 26 is rotatably connected to the side of the floating support 11 near the pressure floating adjustment device 9. The other end of the second shear bar 26 extends to the movable base 30, and a corresponding elongated guide groove 27 is provided on the movable base 30. The end of the second shear bar 26 is slidably disposed in the guide groove 27, and can slide along the guide groove 27 and also rotate at a small angle within the groove. Furthermore, the first shear bar 10 and the second shear bar 26 cross at the middle position and are rotatably connected together by a pin or pivot, thereby forming a scissor-like structure (or scissor linkage mechanism). An angle sensor 25 is also provided at the intersection of the two. The angle sensor 25 is used to monitor the change of the angle between the first scissor bar 10 and the second scissor bar 26 in real time, and transmit the detected angle signal to the central control device 4 in real time.

[0022] To cooperate with the aforementioned adjustment mechanism and achieve closed-loop control of yarn tension, a tension detection element is also provided on the base 29. Specifically, on the side of the base 29 away from the arc-shaped mounting plate 1, near the first yarn guide plate 5 (i.e., yarn inlet 24), a yarn inlet tension sensor 6 is fixedly installed; on the side of the base 29 away from the arc-shaped mounting plate 1, near the second yarn guide plate 17 (i.e., yarn outlet 16), a yarn outlet tension sensor 8 is fixedly installed. After the yarn enters from the yarn inlet 24, it passes through the yarn inlet tension sensor 6, the two yarn guide rollers 12 (guided by the floating support 11), and the yarn outlet tension sensor 8 in sequence as it travels to the yarn outlet 16. The yarn inlet tension sensor 6 and the yarn outlet tension sensor 8 detect the tension value of the yarn in real time when it enters and leaves the adjustment device, and transmit the detected pressure signal to the central control device 4 in real time.

[0023] The working logic and adjustment process of this device are as follows: The central control device 4 receives the detection values ​​of the yarn infeed tension sensor 6 and the yarn outlet tension sensor 8 in real time and compares them with the preset standard tension value. When a tension deviation is detected, the central control device 4 first determines whether to perform coarse or fine adjustment. On one hand, the central control device 4 can control the drive motor 15 to start, driving the moving seat 30 to move as a whole through the threaded rod 28, thereby quickly changing the relative position of the floating support seat 11 and the yarn guide wheel 12 with the yarn path, and performing a rapid and large-scale preliminary adjustment of the yarn tension. On the other hand, the central control device 4 controls the pressure floating adjustment device 9 to move, driving one end of the first shear rod 10 connected to it to move. Since the first shear rod 10 and the second shear rod 26 form a scissor structure, the movement of the first shear rod 10 will drive the second shear rod 26 to slide and rotate in the guide groove 27, thereby pushing the floating support seat 11, which is rotatably connected to the second shear rod 26, to rotate around the pin shaft 14. The rotation of the floating support seat 11 will change the contact angle and wrap angle between the two yarn guide wheels 12 and the yarn, thereby performing fine adjustment of the yarn tension. During fine-tuning, the angle sensor 25 feeds back the angle between the first shear bar 10 and the second shear bar 26 to the central control device 4 in real time, forming an internal closed-loop position control. By combining coarse adjustment (moving seat 30) and fine adjustment (rotating floating support seat 11), both rapid response and precision of tension adjustment are ensured.

[0024] Next, the specific structure of the pressure floating adjustment device 9 will be described in detail. The pressure floating adjustment device 9 includes a hollow piston chamber 22 filled with magnetorheological fluid. Magnetorheological fluid is a smart material whose rheological properties (such as viscosity and shear yield stress) change rapidly and reversibly under the action of a magnetic field. A push plate 21 is slidably disposed inside the piston chamber 22, and the outer edge of the push plate 21 is sealed and slidably engaged with the inner wall of the piston chamber 22. A push rod 19 is connected to the center position of the push plate 21 near the first shear rod 10. One end of the push rod 19 is fixed to the push plate 21, and the other end extends to the outside of the piston chamber 22. A connector 18 is fixedly disposed at the end of the push rod 19 located outside the piston chamber 22. The connector 18 is rotatably connected to one end of the first shear rod 10 by means of a pin or the like. A magnetic control coil 20 is wound around the outside of the piston chamber 22. The lead of the magnetic control coil 20 extends to the outside of the pressure floating adjustment device 9 and is electrically connected to the central control device 4. When the central control device 4 applies current to the magnetic control coil 20, the coil generates a magnetic field. This magnetic field acts on the magnetorheological fluid inside the piston chamber 22, instantly changing its viscosity, thereby generating a damping force on the movement of the push plate 21 within the piston chamber 22. By adjusting the current, the magnitude of the damping force can be precisely controlled, thereby controlling the moving speed and output force of the push rod 19. Inside the piston chamber 22, a return spring 23 is also provided on the side of the push plate 21 away from the push rod 19. When the magnetic control coil 20 is de-energized or the current decreases, the magnetic field weakens, and the magnetorheological fluid returns to a low viscosity state. At this time, the elastic force of the return spring 23 pushes the push plate 21 and the push rod 19 to move in the opposite direction, achieving reset. This structure makes the pressure floating adjustment device 9 an electrically controlled, rapidly responding linear actuator, capable of precisely controlling the movement of the first shear bar 10 according to the instructions of the central control device 4.

[0025] In the entire device, the drive motor 15, the yarn infeed tension sensor 6, the yarn outfeed tension sensor 8, the magnetic control coil 20, and the angle sensor 25 are all connected to the central control device 4 via signal lines. The central control device 4 has a preset control algorithm that performs comprehensive calculations based on the received data from multiple sensors (yarn infeed tension, yarn outfeed tension, and shear bar angle), and then sends control commands to the drive motor 15 and the magnetic control coil 20 respectively to drive the corresponding actuators to act, forming a complete, multi-feedback closed-loop control system to ensure that the yarn tension is always stable within the preset range.

[0026] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the invention and are not intended to limit it. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the invention, but such modifications, substitutions, and variations are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A yarn tension adjusting device for a circular knitting machine, comprising: Arc-shaped mounting plate (1), with a circular structure; Several wire guiding devices (2) are evenly distributed on the outer ring of the arc-shaped mounting plate (1); A grid plate (3) is disposed at the bottom of the arc-shaped mounting plate (1); The central control device (4) is located on the top of the arc-shaped mounting plate (1); The wire guiding device (2) includes: The base (29) is fixedly installed on the outer wall of the arc-shaped mounting plate (1); The first thread guide plate (5) and the second thread guide plate (17) are respectively inclinedly disposed at the top and bottom of the base (29). The first thread guide plate (5) has a yarn inlet (24) and the second thread guide plate (17) has a yarn outlet (16). The movable seat (30) is slidably mounted on the base (29); A drive mechanism, located on the base (29), is used to drive the movable seat (30) to slide along the base (29); The floating support mechanism includes a Y-shaped floating support seat (11) rotatably mounted on the movable seat (30), and wire guide wheels (12) located at both ends of the Y-shaped floating support seat (11). The pressure floating adjustment device (9) finely adjusts the angle of the floating support (11).

2. The yarn tension adjusting device for a circular knitting machine according to claim 1, characterized in that, The drive mechanism includes: A fixing plate (7) is provided on the base (29) on the side near the yarn inlet (24); A drive motor (15) is located on the base (29) on one side near the fixing plate (7); A threaded rod (28) is connected to the output end of the drive motor (15) and passes through the movable seat (30) to drive the movable seat (30) to reciprocate along the base (29).

3. The yarn tension adjusting device for a circular knitting machine according to claim 1, characterized in that, The floating support mechanism also includes: A limiting plate (13) is provided on the movable seat (30); A pin (14) is provided through the single end of the limiting plate (13) and the Y-shaped floating support (11), so that the Y-shaped floating support (11) is rotatably connected to the movable seat (30).

4. The yarn tension adjusting device for a circular knitting machine according to claim 1, characterized in that, The movable seat (30) is provided with a guide groove (27), and the end of the second shear bar (26) is slidably disposed in the guide groove (27); An angle sensor (25) is provided at the intersection of the first scissor bar (10) and the second scissor bar (26) to monitor the rotation angle of the two. The angle sensor (25) is electrically connected to the central control device (4).

5. The yarn tension adjusting device for a circular knitting machine according to claim 1, characterized in that, The pressure floating regulating device (9) includes: The piston chamber (22) is filled with magnetorheological fluid; The push plate (21) is slidably disposed within the piston chamber (22); The push rod (19) is connected at one end to the push plate (21) and at the other end extends to the outside of the piston chamber (22); A connector (18) is located at the end of the push rod (19) and is rotatably connected to one end of the first shear rod (10); A magnetic control coil (20) is wound around the outside of the piston cavity (22) and electrically connected to the central control device (4).

6. The yarn tension adjusting device for a circular knitting machine according to claim 5, characterized in that, The piston chamber (22) is also provided with a return spring (23), which is located on the side of the push plate (21) away from the push rod (19).

7. The yarn tension adjusting device for a circular knitting machine according to claim 1, characterized in that, A pressure floating adjustment device (9) is provided on the movable seat (30), and its output end is connected to a first shear rod (10). The second shear bar (26) is rotatably connected at one end to the Y-shaped floating support (11) and slidably engaged with the movable seat (30) at the other end; The middle sections of the first shear bar (10) and the second shear bar (26) are cross-rotated to form a scissor structure; The pressure floating adjustment device (9) is used to drive the first shear bar (10) to move in order to adjust the angle of the Y-shaped floating support (11).

8. The yarn tension adjusting device for a circular knitting machine according to claim 1, characterized in that, The yarn tension sensor (6) and the yarn tension sensor (8) are respectively located on the base (29) on one side near the first thread guide plate (5) and the second thread guide plate (17) for detecting yarn tension. The yarn tension sensor (6), the yarn tension sensor (8), and the drive mechanism are all electrically connected to the central control device (4).

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