A yarn tension detection device in a textile machine

Abstract

This application relates to the field of sensors, specifically disclosing a yarn tension detection device for textile machinery. The device includes an operating table with two spaced-apart first yarn feed rollers and two second yarn feed rollers, and a tension detection device positioned between the first and second yarn feed rollers. The tension detection device includes: a hydraulic cylinder with its bottom movably mounted on the operating table, its rodless cavity filled with magnetorheological fluid; an elastic expansion tube disposed on the sidewall of the rodless cavity; a yarn guide assembly disposed on the piston shaft of the hydraulic cylinder; a pressure sensor disposed on the bottom of the cylinder and movably mounted on the operating table; and an electromagnet disposed on the sidewall of the hydraulic cylinder. This application can flexibly adapt to yarn tension fluctuations, suppress inertial interference, and improve detection accuracy and stability.

Description

Technical Field

[0001] This application relates to the field of sensors, and in particular to a yarn tension detection device for textile machinery. Background Technology

[0002] In the process of textile machinery yarn processing and production, the stability of yarn tension directly determines the quality of yarn weaving, and the accuracy of tension detection is a key factor in ensuring the flatness and yield of finished textile products.

[0003] In existing technology, the tension of yarn is not constant during the conveying process in textile equipment; it fluctuates within a certain range. As long as the fluctuation range meets the production requirements, it is acceptable. Adjusting the yarn tension inevitably requires tension detection, and the two are interdependent.

[0004] A typical yarn tension regulating device consists of a telescopic component installed on an operating table, with a yarn guide roller mounted on the telescopic component. As the yarn passes through the yarn guide roller, the telescopic component adaptively expands and contracts based on tension fluctuation data detected by a tension sensor, maintaining the yarn tension within a suitable range.

[0005] Currently, there are two main modes for adjusting yarn tension: The first scenario: If the telescopic mechanism of the retractable thread guide is an active mechanism, such as a cylinder, although the pressure sensor data is more accurate, the pressure sensor must detect the tension data first before the cylinder adjusts its extension and retraction. This introduces a tension adjustment delay, and the cylinder also struggles to adapt to the thread tension in real time. In other words, this method provides accurate pressure sensor data but suffers from a delay in thread tension adjustment.

[0006] The second method involves using an elastic telescopic component on the retractable thread guide. This component can adaptively expand and contract in real time based on fluctuations in thread tension, maintaining the thread tension within a suitable range. If the thread tension tends to exceed the elastic adjustment range of the component, its height can be proactively adjusted using a cylinder or other electric telescopic mechanism, bringing the tension fluctuation back within the adjustment range. However, because the thread tension fluctuates in real time, the pressure sensor's data will be less accurate. In other words, this method ensures no delay in thread tension adjustment, but the pressure sensor's data measurement is less precise.

[0007] Furthermore, when traditional detection structures adaptively adjust to changes in yarn tension, they are prone to mechanical inertial vibrations due to elastic stretching, causing tension detection deviations and failing to achieve high-precision, continuous dynamic tension monitoring.

[0008] In summary, existing technologies lack a detection structure that can adaptively buffer tension fluctuations and effectively counteract inertial interference during mechanical elastic expansion and contraction. This makes it difficult to meet the detection needs of high-speed textile production, resulting in poor detection stability and low accuracy.

[0009] Therefore, there is an urgent need for a yarn tension testing device that can flexibly adapt to yarn tension fluctuations, suppress inertial interference during elastic stretching, and has excellent detection accuracy and stability, in order to overcome the shortcomings of existing technologies and meet the high-precision testing needs of modern textile production. Summary of the Invention

[0010] In order to flexibly adapt to yarn tension fluctuations, suppress inertial interference, and improve detection accuracy and stability, this application provides a yarn tension detection device for textile machinery.

[0011] The technical solution of the yarn tension testing device in textile machinery provided in this application is as follows: A yarn tension detection device for textile machinery includes an operating table, on which two first yarn feed rollers and two second yarn feed rollers are arranged at intervals, and a tension detection device is disposed between the first yarn feed rollers and the second yarn feed rollers; The tension detection device includes: A hydraulic cylinder, with its bottom movable and mounted on the operating platform, has a rodless cavity filled with magnetorheological fluid; An elastic expansion tube is provided on the side wall of the rodless cavity; The wire guide assembly is mounted on the piston shaft of the hydraulic cylinder; A pressure sensor is located at the bottom of the cylinder and is vertically mounted on the operating platform; and, An electromagnet is disposed on the side wall of the hydraulic cylinder; The first two feed rollers and the second two feed rollers clamp the feed wire, allowing the wire to pass stably through the wire guide assembly. The piston shaft extends and retracts with the tension of the wire, squeezing or releasing the magnetorheological fluid, causing the elastic expansion tube to expand and reset adaptively, flexibly adapting to the tension fluctuations of the wire. The electromagnet operates intermittently, magnetizing the magnetorheological fluid and instantly solidifying it when energized, locking the position of the piston shaft and suppressing inertial interference. At this time, the pressure sensor detects the tension of the wire acting on the wire guide assembly in real time. When the power is off, the magnetorheological fluid returns to a liquid state, allowing the piston shaft to elastically extend and retract again.

[0012] Optionally, an elastic telescopic member is connected between the piston of the hydraulic cylinder and the bottom of the cylinder.

[0013] Optionally, when the travel of the elastic telescopic member is at its shortest and / or when the elastic expansion tube expands to its maximum volume, the piston is positioned above the elastic expansion tube.

[0014] Optionally, the elastic expansion tube includes: The side tube has one end connected to the rodless cavity; An elastic membrane seals the other end of the side tube.

[0015] Optionally, a lifting device is connected between the tension detection device and the operating table; A guide rod that is slidably connected to the operating table is installed on the bottom of the cylinder or the side tube.

[0016] Optionally, the tension detection device further includes: The guide sleeve is closed at one end and connected to the bottom of the cylinder, and has an opening at the other end, and is slidably sleeved on the upper end of the lifting device; The pressure sensor is located inside the guide sleeve, with one end connected to the closed end of the guide sleeve and the other end connected to the upper end of the lifting device.

[0017] Optionally, the first and second wire feed rollers are spaced apart along the length of the operating table; The wire-passing component includes: An elastic sheet is provided along the length of the operating table, and its middle part is connected to the closed end of the guide sleeve; Multiple thread loops are spaced apart along the length of the elastic sheet.

[0018] Optionally, the wire guide ring is positioned above the elastic sheet, and both ends of the elastic sheet are bent downwards.

[0019] In summary, this application includes at least one of the following beneficial technical effects: 1. During operation of the equipment in this application, the first and second wire feeding wheels rotate, actively clamping and stably feeding the wire, ensuring the wire remains constantly in contact with the wire feeding assembly. During normal wire feeding, the pressure sensor in this application has two operating modes: dynamic detection and static detection, as follows: When dynamically detecting wire tension, the tension fluctuations of different types of wires vary, and the elastic vibration strokes of different types of elastic membranes and elastic expansion joints also differ. This application adjusts the magnetic field strength by adjusting the power of the electromagnet, thereby adjusting the viscosity and damping of the magnetorheological fluid. During operation, the viscosity and damping of the magnetorheological fluid can be specifically adjusted according to the selection of the wire, elastic membrane, and elastic expansion joint, as well as actual production needs. This allows the wire, elastic membrane, and elastic expansion joint to elastically fluctuate within the allowable fluctuation range during normal operation, preventing excessive elastic vibration amplitude and shaking amplitude from affecting the wire tension adjustment and the detection accuracy of the pressure sensor. To counteract the mechanical inertial jitter caused by the reciprocating deformation of the expansion tube and the elastic vibration of the elastic diaphragm and elastic expansion member during static wire tension detection, the PLC incorporates intermittent control timing logic. During equipment operation, the PLC outputs an energizing signal according to a preset intermittent cycle, causing the electromagnet to intermittently start at maximum power. During the short-term maximum power of the electromagnet, the magnetorheological fluid instantaneously solidifies and locks the elastic diaphragm. This position of the elastic expansion member and piston shaft suppresses inertial interference and eliminates detection drift. At this time, the wire guide assembly is static, allowing the pressure sensor to more accurately detect the tension of the wire acting on the guide assembly. After static wire tension detection is completed, the electromagnet immediately reduces its power to return to the level used for dynamic wire tension detection, restoring the magnetorheological fluid to a fluid with a certain viscosity and damping, enabling the piston shaft to elastically float based on wire tension fluctuations. In this application, the short-term maximum power solidification of the magnetorheological fluid and the restoration of the magnetorheological fluid to a fluid with a certain viscosity and damping when the electromagnet reduces its power are based on a preset timing closed-loop cycle, achieving high-precision and high-stability detection of the wire's dynamic tension throughout the entire process. Based on two sets of pressure data—dynamic and static—the system jointly determines whether the wire tension fluctuates within the preset tension benchmark threshold's allowable range. When the wire tension fluctuation exceeds the allowable range or shows a tendency to do so, if the wire tension is too high, the cylinder bottom actively lowers; if the wire tension is too low, the cylinder bottom actively raises. This, in turn, through the active raising and lowering of the entire hydraulic cylinder, brings the wire tension fluctuation back within the preset tension benchmark threshold's allowable range.

[0020] 2. In this application, the electromagnet is controlled to intermittently switch on and off. Under normal conditions, the magnetorheological fluid remains in a liquid state to ensure real-time response. Short-term electromagnetization can cause the magnetorheological fluid to solidify instantaneously and lock the piston shaft position, effectively offsetting the mechanical inertial vibration caused by the reciprocating deformation of the elastic expansion tube and the movement of the piston shaft. At this time, the pressure sensor detects the tension of the wire acting on the wire-passing assembly in real time, which can realize high-precision detection of wire tension. Combined with the intermittent switching on and off of the electromagnet, high-precision dynamic continuous detection can be achieved.

[0021] 3. In this application, the lifting device and the guide rod work together to quickly correct the tension of the yarn to the standard range when the yarn tension fluctuation exceeds the preset allowable range, by driving the bottom of the cylinder to actively adjust the position through the lifting device, thus adapting to the complex fluctuation conditions of the yarn.

[0022] 4. In this application, a thread guide assembly with elastic sheets bent downwards at both ends and multiple sets of spaced thread guide rings is used. The thread guide rings precisely define the thread routing position, and the elastic sheets can achieve smooth transition of the thread at large angles. This avoids stress concentration and thread breakage caused by the small corners of traditional thread routing structures, thereby improving thread routing stability and product yield.

[0023] 5. In this application, the pressure sensor is built into the guide sleeve, which can accurately limit the direction of force on the sensor and avoid lateral force interference with the detection data. The piston's extreme position is always above the elastic expansion tube. Together with the elastic telescopic component between the piston and the cylinder bottom, it ensures stable cavity buffer stroke and smooth piston shaft reset, further improving the overall operational stability and detection repeatability of the equipment. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a top view of the tension detection device. Figure 3 It is along Figure 2 Schematic diagram of the cross-sectional structure along line AA in the middle.

[0026] Figure label: 1. Operating platform; 11. First wire feeding wheel; 12. Second wire feeding wheel; 2. Tension detection device; 20. Magnetorheological fluid; 21. Hydraulic cylinder; 2101. Rodless chamber; 22. Piston; 23. Piston shaft; 24. Elastic telescopic component; 25. Elastic expansion tube; 251. Side tube; 252. Elastic membrane; 26. Wire guiding assembly; 261. Elastic sheet; 262. Wire guiding ring; 27. Pressure sensor; 271. Guide sleeve; 28. Electromagnet; 29. ​​Lifting device; 291. Guide rod. Detailed Implementation

[0027] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0028] This application discloses a yarn tension testing device for textile machinery.

[0029] Reference Figure 1-3 A yarn tension detection device for textile machinery includes an operating table 1, on which two first yarn feeding wheels 11 and two second yarn feeding wheels 12 are spaced apart, and a tension detection device 2 is disposed between the first yarn feeding wheels 11 and the second yarn feeding wheels 12. Specifically, the first yarn feeding wheels 11 and the second yarn feeding wheels 12 are spaced apart along the length of the operating table 1. Both the first yarn feeding wheels 11 and the second yarn feeding wheels 12 are actively driven to rotate by conventional high-precision motors such as servo motors. Both the first yarn feeding wheels 11 and the two second yarn feeding wheels 12 actively clamp and feed yarn. Tension detection device 2 includes: The hydraulic cylinder 21 is vertically arranged, and its bottom can be raised and lowered on the operating platform 1. Its rodless cavity 2101 is filled with magnetorheological fluid 20. The elastic expansion tube 25 is located on the side wall of the rodless cavity 2101; The wire guide assembly 26 is mounted on the piston shaft 23 of the hydraulic cylinder 21; Pressure sensor 27 is located at the bottom of the cylinder and is mounted on the control panel 1 in a height-adjustable manner; and, Electromagnet 28 is located on the side wall of hydraulic cylinder 21; Two first feed rollers 11 and two second feed rollers 12 clamp the feed wire, allowing it to pass stably through the wire guide assembly 26. The piston shaft 23 extends and retracts with the tension of the wire, squeezing or releasing the magnetorheological fluid 20. This causes the elastic expansion tube 25 to expand and reset adaptively, flexibly adapting to the fluctuations in wire tension. The electromagnet 28 operates intermittently, magnetizing the magnetorheological fluid 20 when energized, causing it to solidify instantaneously, locking the position of the piston shaft 23 and suppressing inertial interference. At this time, the pressure sensor 27 detects the tension of the wire acting on the wire guide assembly 26 in real time. When the power is off, the magnetorheological fluid 20 returns to a liquid state, allowing the piston shaft 23 to elastically extend and retract again, ensuring that the equipment responds normally to tension changes and improving the accuracy and stability of wire tension detection.

[0030] Reference Figure 1-3 In this embodiment, a controller (PLC, microcontroller, etc., not shown in the figure) is used to control the operation of various components. For example, the entire application is controlled by a unified PLC controller, and those skilled in the art can reproduce the linkage logic of the whole machine without creative effort based on this description. Specifically, the analog signal output terminal of the pressure sensor 27 is electrically connected to the analog input port of the PLC via a signal line to upload the wire tension detection value in real time; the drive terminals of the two servo motors and the hydraulic cylinder 21, along with the matching electromagnet 28, are respectively connected to the corresponding digital output ports of the PLC via relays to achieve precise control of start / stop and on / off states.

[0031] The specific work process is as follows: This application sets a preset tension reference threshold and a fluctuation allowable range. These preset tension reference threshold and fluctuation allowable range can be adaptively adjusted according to the yarn material, diameter, and weaving process parameters, and are stored in a fixed internal register of the PLC. During equipment operation, the PLC controls two sets of high-precision servo motors to synchronously drive the first feed roller 11 and the second feed roller 12 to rotate, actively clamping and stably feeding the yarn, ensuring the yarn maintains a constant contact with the yarn guide assembly 26. The pressure sensor 27 continuously collects real-time yarn tension data and uploads it to the PLC, which compares the detected value with the preset tension reference threshold in real time.

[0032] When the wire initially passes through the wire guide assembly 26, the first wire guide wheel 11 and the second wire guide wheel 12 first rotate at different speeds to pull the wire, or the height of the cylinder bottom is adjusted appropriately so that the wire tension is at the preset tension reference threshold, and then the first wire guide wheel 11 and the second wire guide wheel 12 run at the same speed.

[0033] During normal yarn feeding, piston shaft 23 is also under pressure. When the yarn tension fluctuation is within the allowable range, piston shaft 23 pushes piston 22 to squeeze magnetorheological fluid 20 in rodless cavity 2101 within a certain pressure range, causing elastic expansion tube 25 on side wall to expand and reset adaptively. At this time, piston shaft 23 can elastically expand and contract with tension changes, and combined with magnetorheological fluid 20, it can flexibly buffer and adapt to tension fluctuations, reducing detection errors.

[0034] During normal yarn feeding, continuous yarn tension monitoring is required. In existing technologies, the static calibration accuracy of the same yarn tension / pressure sensor (measuring yarn, chemical fiber filament, and fabric warp pressure) is generally better than the measured accuracy under dynamic high-speed yarn feeding conditions. Dynamic detection has inherent error sources and cannot achieve the same level of static zero-point / linear accuracy. Therefore, the pressure sensor 27 of this application has two operating modes: dynamic detection and static detection, as detailed below: When dynamically detecting the tension of a yarn, the tension fluctuations of different types of yarns vary, and the elastic vibration strokes of different types of elastic membranes 252 and elastic expansion joints 24 also differ. This application adjusts the magnetic field strength by adjusting the power of the electromagnet 28, thereby adjusting the viscosity and damping of the magnetorheological fluid 20. During operation, the viscosity and damping of the magnetorheological fluid 20 can be specifically adjusted according to the selection of the yarn, elastic membrane 252, and elastic expansion joint 24, as well as actual production needs. This allows the yarn, elastic membrane 252, and elastic expansion joint 24 to elastically fluctuate within the allowable fluctuation range during normal operation, while reducing the vibration of the yarn guide assembly 26. This prevents the elastic membrane 252 and elastic expansion joint 24 from affecting the yarn tension adjustment and the detection accuracy of the pressure sensor 27 due to excessive elastic vibration amplitude, vibration, or shaking amplitude.

[0035] During static detection of wire tension, to counteract the mechanical inertial jitter caused by the reciprocating deformation of the expansion tube and the elastic vibration of the elastic diaphragm 252 and the elastic expansion member 24, the PLC incorporates intermittent control timing logic. During equipment operation, the PLC outputs a power signal according to a preset intermittent cycle, causing the electromagnet 28 to intermittently start at maximum power. When the electromagnet 28 is at its short-term maximum power, the magnetorheological fluid 20 instantaneously solidifies and locks the positions of the elastic diaphragm 252, the elastic expansion member 24, and the piston shaft 23, suppressing inertial interference and preventing detection drift. At this time, the wire guide assembly 26 is static, allowing the pressure sensor 27 to more accurately detect the tension of the wire acting on the wire guide assembly 26. After static detection of wire tension is completed, the electromagnet 28 immediately reduces its power to the level used for dynamic detection of wire tension, restoring the magnetorheological fluid 20 to a fluid with a certain viscosity and damping, enabling the piston shaft 23 to elastically float based on fluctuations in wire tension.

[0036] In this application, the electromagnet 28 briefly solidifies the magnetorheological fluid 20 at its maximum power, and when the electromagnet 28 reduces its power, the magnetorheological fluid 20 is restored to a fluid state with a certain viscosity and damping. Based on a preset time-series closed-loop cycle, high-precision and high-stability detection of the wire's dynamic tension is achieved throughout the process. Based on two sets of pressure data—dynamic and static—it is jointly determined whether the wire tension fluctuates within the preset tension reference threshold's allowable fluctuation range. When the wire tension fluctuation exceeds the allowable fluctuation range or shows a tendency to exceed it, if the wire tension is too high, the cylinder bottom actively lowers its height; if the wire tension is too low, the cylinder bottom actively raises its height. This, in turn, through the overall active lifting and lowering of the cylinder bottom (hydraulic cylinder 21), brings the wire tension fluctuation back within the preset tension reference threshold's allowable fluctuation range.

[0037] Reference Figure 1-3An elastic telescopic member 24 connects the piston 22 of the hydraulic cylinder 21 to the cylinder bottom. When the stroke of the elastic telescopic member 24 is at its shortest and / or when the elastic expansion tube 25 expands to its maximum volume, the piston 22 is located above the elastic expansion tube 25.

[0038] Multiple elastic expansion tubes 25 are provided, and the multiple elastic expansion tubes 25 are evenly spaced along the circumference of the rodless cavity 2101. The elastic expansion tubes 25 include: Side tube 251, one end of which is connected to rodless cavity 2101; The elastic membrane 252 seals the other end of the side tube 251.

[0039] Reference Figure 1-3 In this embodiment, when the tension of the wire fluctuates, the piston shaft 23 extends and retracts with the tension change, squeezing or releasing the magnetorheological fluid 20 in the rodless cavity 2101. The side tubes 251 of each elastic expansion tube 25 are connected to the rodless cavity 2101, and the outside of the side tubes 251 is sealed by an elastic membrane 252. The elastic membrane 252 can expand and reset synchronously and uniformly with the change of oil pressure in the cavity, flexibly adapting to the dynamic fluctuation of the wire tension. The elastic telescopic member 24 set between the bottom of the hydraulic cylinder 21 and the piston 22 can assist the piston shaft 23 in adaptive reset and buffer the impact of movement. The structure limits the stroke of the elastic telescopic member 24 to the shortest and the piston 22 to always be above the elastic expansion tube 25 when the elastic expansion tube 25 is expanded to its maximum volume. This can ensure the stability of the effective working volume and deformation buffer stroke of the cavity. With the continuous detection of the pressure sensor 27, it is conducive to the stable completion of high-precision detection of wire tension.

[0040] Reference Figure 1-3 A lifting device 29 is connected between the tension detection device 2 and the operating table 1; A guide rod 291 that is slidably connected to the operating table 1 is installed on the bottom of the cylinder or the side tube 251.

[0041] Reference Figure 1-3 In this embodiment of the application, when the tension fluctuation of the yarn exceeds the allowable fluctuation range, the lifting device 29 drives the bottom of the cylinder to actively lift and lower, so that the tension fluctuation of the yarn returns to the allowable fluctuation range.

[0042] Reference Figure 1-3 The tension detection device 2 also includes: The guide sleeve 271 is closed at one end and connected to the bottom of the cylinder, and has an opening at the other end, and is slidably sleeved on the upper end of the lifting device 29. The pressure sensor 27 is located inside the guide sleeve 271, with one end connected to the closed end of the guide sleeve 271 and the other end connected to the upper end of the lifting device 29.

[0043] Reference Figure 1-3In this embodiment, the guide sleeve 271 further defines the force direction of the pressure sensor 27, thereby achieving accurate tension acquisition.

[0044] Reference Figure 1-3 The wire guide assembly 26 includes: The elastic sheet 261 is arranged along the length of the operating table 1 and its middle part is connected to the closed end of the guide sleeve 271. Here, the elastic sheet 261 is a spring sheet. Multiple wire guide rings 262 are distributed at intervals along the length of the elastic sheet 261. Here, the wire guide rings 262 are circular rings with a circular axial cross section.

[0045] Specifically, the wire guide ring 262 is positioned above the elastic sheet 261; The two ends of the elastic sheet 261 are bent downwards.

[0046] Reference Figure 1-3 In this embodiment, multiple wire guide rings 262 can effectively limit the position of the wire; relying on the elastic deformation characteristics of the elastic sheet 261 and the downward bending of both ends of the elastic sheet 261, the wire can achieve a large-angle, smooth bending transition, avoiding stress concentration and breakage due to excessively small bending angles, and ensuring safe and stable wire routing.

[0047] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0048] The above are all optional embodiments of this application and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A yarn tension testing device for textile machinery, characterized in that: It includes an operating table (1), on which are provided two first wire feeding wheels (11) and two second wire feeding wheels (12) spaced apart, and a tension detection device (2) disposed between the first wire feeding wheels (11) and the second wire feeding wheels (12); The tension detection device (2) includes: The hydraulic cylinder (21) is mounted on the operating table (1) with its bottom adjustable. Its rodless cavity (2101) is filled with magnetorheological fluid (20). An elastic expansion tube (25) is provided on the side wall of the rodless cavity (2101); The wire guide assembly (26) is mounted on the piston shaft (23) of the hydraulic cylinder (21); A pressure sensor (27) is located at the bottom of the cylinder and is mounted on the control panel (1) in a height-adjustable manner; and, An electromagnet (28) is provided on the side wall of the hydraulic cylinder (21); Two first feed rollers (11) and two second feed rollers (12) clamp the feed wire, allowing the wire to pass stably through the wire guide assembly (26). The piston shaft (23) extends and retracts with the change in wire tension, squeezing or releasing the magnetorheological fluid (20), causing the elastic expansion tube (25) to expand and reset adaptively, flexibly adapting to the fluctuation of wire tension. The electromagnet (28) works intermittently, magnetizing the magnetorheological fluid (20) when energized, causing it to solidify instantaneously, locking the position of the piston shaft (23) and suppressing inertial interference. At this time, the pressure sensor (27) detects the tension of the wire acting on the wire guide assembly (26) in real time. When the power is off, the magnetorheological fluid (20) returns to a liquid state, allowing the piston shaft (23) to elastically extend and retract again.

2. The yarn tension testing device in textile machinery according to claim 1, characterized in that: An elastic telescopic member (24) is connected between the piston (22) of the hydraulic cylinder (21) and the bottom of the cylinder.

3. The yarn tension testing device in textile machinery according to claim 1, characterized in that: When the travel of the elastic telescopic member (24) is at its shortest and / or when the elastic expansion tube (25) expands to its maximum volume, the piston (22) is located above the elastic expansion tube (25).

4. The yarn tension testing device in textile machinery according to claim 1, characterized in that: The elastic expansion tube (25) includes: The side tube (251) is connected at one end to the rodless cavity (2101); An elastic membrane (252) seals the other end of the side tube (251).

5. The yarn tension detection device in textile machinery according to claim 4, characterized in that: A lifting device (29) is connected between the tension detection device (2) and the operating table (1). A guide rod (291) that is slidably connected to the operating table (1) is installed on the bottom of the cylinder or the side tube (251).

6. The yarn tension testing device in textile machinery according to claim 5, characterized in that: The tension detection device (2) also includes: The guide sleeve (271) is closed at one end and connected to the bottom of the cylinder, and has an opening at the other end, and is slidably sleeved on the upper end of the lifting device (29); The pressure sensor (27) is located inside the guide sleeve (271), with one end connected to the closed end of the guide sleeve (271) and the other end connected to the upper end of the lifting device (29).

7. The yarn tension testing device in textile machinery according to claim 1, characterized in that: The first feed roller (11) and the second feed roller (12) are spaced apart along the length of the operating table (1); The wire guide assembly (26) includes: An elastic sheet (261) is arranged along the length of the operating table (1), and its middle part is connected to the closed end of the guide sleeve (271); Multiple thread loops (262) are spaced apart along the length of the elastic sheet (261).

8. The yarn tension testing device in textile machinery according to claim 7, characterized in that: The thread loop (262) is located above the elastic sheet (261), and both ends of the elastic sheet (261) are bent downwards.

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