Steam-drafter fiber tow running state monitoring device and control method

Abstract

The application provides a steam drafter fiber bundle running state monitoring device and a control method, wherein the monitoring device comprises a tension detection device and a steam drafter, the tension detection device comprises a mounting bracket, a telescopic cylinder is assembled on the mounting bracket, a first guide roller is arranged on the telescopic rod of the telescopic cylinder, the tension detection device further comprises a tension sensor and a stability judgment module, the first guide roller is connected with the telescopic rod through the tension sensor, and the stability judgment module is configured to judge the long-range stability of the fiber bundle tensioned on the first guide roller according to the real-time tension value detected by the tension sensor. The application can detect the long-range stability of the polyacrylonitrile fiber bundle in the guiding drafting process, can guide the operator to judge the long-range stability of the fiber before winding the fiber, is favorable for timely processing of the production line, guarantees the fiber quality of the production line, and reduces the risk of processing the wound fiber as a degraded product and the production cost.

Description

Technical Field

[0001] This invention belongs to the field of carbon fiber production technology, specifically relating to a monitoring device and control method for the operating status of fiber bundles in a steam drawing machine. Background Technology

[0002] Polyacrylonitrile-based carbon fiber is an inorganic fiber material prepared by high-temperature treatment using polyacrylonitrile fiber (i.e., polyacrylonitrile-based precursor) as a precursor. It has been widely used in aerospace, national defense, cultural and sports activities, automotive industry, new energy, infrastructure, civil engineering and construction and other fields.

[0003] Polyacrylonitrile (PAC) fiber is a prerequisite for producing high-performance carbon fiber, and its stability directly affects the quality of PAC-based carbon fiber products. This is especially true for carbon fibers used in the aerospace field, which places even higher demands on PAC fiber stability. This stability includes the changes in fiber performance at a single spinning point over time and the differences in fiber performance between different spinning points. Currently, methods for characterizing PAC fiber stability typically focus on the dispersion of various performance indicators of the wound PAC fiber, such as mechanical properties and linear density. However, this characterization method only applies to the wound PAC fiber and cannot monitor the PAC fiber in real time during the manufacturing process (e.g., during winding). When fiber stability issues arise during winding, relevant information cannot be obtained promptly. In the industrial production of PAC fiber, there are often multiple spinning points; if fiber stability problems are not detected in time, it will result in significant fiber waste, decreased fiber performance, and increased production costs. Summary of the Invention

[0004] Therefore, the present invention provides a monitoring device and control method for the operating status of fiber bundles in a steam drawing machine, which can overcome the technical problem in the prior art that lacks real-time monitoring of the stability of polyacrylonitrile fiber production process, resulting in the inability to detect the stability problem of polyacrylonitrile fiber in a timely manner so as to carry out necessary treatment, causing fiber waste, and leading to a decline in fiber performance and an increase in production costs.

[0005] To address the aforementioned problems, this invention provides a fiber bundle operation status monitoring device for a steam drafting machine, comprising a tension detection device and a steam drafting machine. The tension detection device is configured corresponding to the target spinning position of the steam drafting machine. The tension detection device includes a mounting bracket, on the first side of which a telescopic cylinder is assembled. A first guide wheel is provided on the free end of the telescopic rod of the telescopic cylinder, and the fiber bundle is tensioned on the first guide wheel. The tension detection device further includes a tension sensor and a stability judgment module. The first guide wheel is connected to the free end of the telescopic rod through the tension sensor. The stability judgment module is configured to determine the long-range stability of the fiber bundle tensioned on the first guide wheel based on the real-time tension value detected by the tension sensor.

[0006] In some embodiments, there are multiple tension detection devices, each of which is set up in a one-to-one correspondence with each spinning position of the steam drafting machine. The stability judgment module is further configured to judge the stability of the fiber bundles at different spinning positions based on the real-time tension values ​​detected by each tension sensor.

[0007] In some embodiments, the first side is further provided with a second guide wheel and a third guide wheel respectively located on both sides of the first guide wheel. The fiber bundle is sequentially tensioned on the first guide wheel, the second guide wheel and the third guide wheel along its insertion and stretching direction. The telescopic rod has an extended position and a retracted position. When the telescopic rod is in the extended position, the telescopic rod applies a preset tension to the fiber bundle in the stretching state via the first guide wheel. When the telescopic rod is in the retracted position, the telescopic rod pulls out a portion of the fiber bundle in the broken state via the first guide wheel.

[0008] In some embodiments, the tension detection device further includes a suction gun, the negative pressure suction port of which is located on the fiber bundle insertion traction path.

[0009] In some embodiments, the suction gun is assembled on the first side, and the negative pressure suction port corresponds to the top surface area of ​​the first guide wheel in the retracted position.

[0010] In some embodiments, the displacement of the telescopic rod from the extended position to the retracted position is L1, and the distance between the inlet of the waste discharge chamber on the inlet side of the steam stretcher and the outlet of the pressure reducing chamber is L2, where 2L1≥L2≥L1.

[0011] In some embodiments, the tension detection device further includes an electromagnetic wheel stop, which is assembled on the first side and is used to brake the second guide wheel when the fiber bundle breaks; the electromagnetic wheel stop can be triggered to brake the second guide wheel and release the brake on the second guide wheel after the suction gun has been running for a preset time.

[0012] The present invention also provides a control method for the fiber bundle operating status monitoring device of the steam drawing machine as described above, comprising the following steps:

[0013] Obtain the real-time tension value Ts of the fiber bundles at each spinning position of the steam drawing machine;

[0014] Determine the magnitude relationship between the real-time tension value Ts and the first preset tension value Ty1;

[0015] When Ty1≥Ts≥0.97Ty1, the long-range stability of the fiber bundles corresponding to each spinning position is obtained, and / or, the stability of the fiber bundles at each different spinning position of the steam drawing machine is obtained.

[0016] When 0.9Ty1 < Ts < 0.97Ty1, an alarm message is issued to prompt the operator to perform maintenance.

[0017] In some embodiments, obtaining the long-range stability of the fiber bundles corresponding to each spinning position includes:

[0018] Obtain N real-time tension values ​​within a preset time interval at the same spinning position, and calculate the first average value T of the N real-time tension values. 平均值1 and the first standard deviation T 标准偏差1 Calculate the stability dispersion coefficient CV of this fiber bundle. 单束 =(T 标准偏差1 / T 平均值1 )×100%, N is not less than 50; or,

[0019] Obtaining the stability of the fiber bundles at different spinning positions in the steam drawing machine includes:

[0020] M real-time tension values ​​are obtained from the fiber bundles corresponding to different spinning positions within a preset time interval in a second preset time period. The number of spinning positions in the steam drawing machine is a. The second average value T of the M×a real-time tension values ​​is calculated. 平均值2 and the second standard deviation T 标准偏差2 Calculate the stability dispersion coefficient CV of the total fiber bundle for all said spinning positions. 所有纺位 =(T 标准偏差2 / T 平均值2 )×100%, M is not less than 20.

[0021] In some embodiments, when the telescopic rod of the steam drawing machine fiber bundle operation status monitoring device has an extended position and a retracted position, and includes a suction gun and an electromagnetic stopper, when Ts≤0.9Ty1, the telescopic rod is controlled to switch from the extended position to the retracted position, the suction gun is controlled to operate synchronously, the electromagnetic stopper is controlled to brake the second guide wheel, and after the suction gun has been running for a preset time, the electromagnetic stopper is controlled to release the brake on the second guide wheel.

[0022] The fiber bundle operation status monitoring device and control method of the steam drawing machine provided by the present invention have the following beneficial effects:

[0023] By installing the tension detection device of this invention at the steam drawing machine, the long-range stability of polyacrylonitrile fiber bundles can be detected online during the guided drawing process. This guides operators to assess the long-range stability of the fibers before winding, facilitating timely adjustments to the production line, ensuring fiber quality, reducing the risk of downgrading wound fibers, and lowering production costs. It is particularly important to emphasize that the tension detection device in this invention uses a tension sensor to achieve online stability detection of the corresponding fiber bundles, requiring minimal modifications to the production line and reducing modification costs. Attached Figure Description

[0024] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram showing the relative positional relationship between the tension detection device and the steam stretching machine in one embodiment of the present invention, wherein the telescopic rod of the tension detection device is in the extended position;

[0026] Figure 2 yes Figure 1 A side view of the tension detection device in the diagram;

[0027] Figure 3 This is a schematic diagram showing the relative positional relationship between the tension detection device and the steam stretching machine in one embodiment of the present invention, wherein the telescopic rod of the tension detection device is in the retracted position;

[0028] Figure 4 yes Figure 3 A side view of the tension detection device.

[0029] The attached figures are labeled as follows:

[0030] 4. Tension detection device; 41. Mounting bracket; 42. Telescopic cylinder; 421. Telescopic rod; 422. First guide wheel; 423. First mounting base; 424. Second mounting base; 431. Second guide wheel; 432. Third guide wheel; 44. Fiber suction gun; 45. Tension sensor; 46. Electromagnetic wheel stopper; 47. Stability judgment module; 400. Fiber bundle; 501. Waste discharge chamber; 502. Pressure reducing chamber; 503. Steam drawing chamber; 504. Steam inlet pipe; 5041. Solenoid valve; 5042. Filter; 5043. Ball valve; 600. Drawing roller. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0035] See also Figures 1 to 4 As shown in the figure, according to an embodiment of the present invention, a device for monitoring the operating status of a steam drawing machine fiber bundle is provided, including a tension detection device 4 and a steam drawing machine (not labeled in the figure). The tension detection device 4 is configured corresponding to the target spinning position of the steam drawing machine (i.e., one of the multiple spinning positions of the steam drawing machine). The tension detection device 4 includes a mounting bracket 41, and a telescopic cylinder 42 is assembled on the first side of the mounting bracket 41. A first guide wheel 422 is provided on the free end of the telescopic rod 421 of the telescopic cylinder 42. The fiber bundle (i.e., polyacrylonitrile fiber bundle, the same below) is tensioned on the first guide wheel 422. That is, after being guided by the first guide wheel 422, the fiber bundle is introduced (or drawn out) into the corresponding position of the steam drawing machine. Within the spinning station, the tension detection device 4 further includes a tension sensor 45 and a stability judgment module 47. The first guide wheel 422 is connected to the free end (i.e., the extended end of the telescopic rod 421) of the telescopic rod 421 via the tension sensor 45. The stability judgment module 47 is configured to determine the long-range stability of the fiber bundle tensioned on the first guide wheel 422 based on the real-time tension value detected by the tension sensor 45. The aforementioned stability judgment module 47 is, for example, a common industrial control computer in the industry. This industrial control computer stores relevant programs that can calculate the long-range stability of the fiber bundle based on the real-time tension value detected by the tension sensor 45, thereby obtaining the long-range stability of the fiber bundle tensioned on the first guide wheel 422. In a specific embodiment, the aforementioned stability judgment module 47 includes a corresponding display screen component. The stability judgment module 47 can also plot the corresponding tension curves of multiple real-time tension values ​​acquired by the tension sensor 45 within a certain time period. The staff can make an apparent judgment on the long-range stability of the fiber bundle by observing the tension curves. For example, if the curve fluctuates greatly, there may be a problem with long-range stability deviation, while a stable curve indicates good long-range stability.

[0036] In this technical solution, by installing the tension detection device 4 of the present invention at the steam drawing machine, the long-range stability of the polyacrylonitrile fiber bundle can be detected online during the guided drawing process. This allows operators to judge the long-range stability of the fiber before winding, facilitating timely processing of the production line, ensuring fiber quality, reducing the risk of downgrading wound fibers, and lowering production costs. It is particularly important to emphasize that the tension detection device 4 in this invention uses a tension sensor 45 to achieve online detection of the stability of the corresponding fiber bundle, requiring minimal modification to the production line and reducing modification costs.

[0037] In some embodiments, there are multiple tension detection devices 4, and each tension detection device 4 is respectively set up in correspondence with each spinning position of the steam drafting machine. The stability judgment module 47 is also configured to judge the stability of the fiber bundles at different spinning positions based on the real-time tension values ​​detected by each tension sensor 45. It should be noted that each tension detection device 4 can share a set of stability judgment module 47, that is, the detection values ​​of each tension sensor 45 are all acquired by the same stability judgment module 47 and processed accordingly.

[0038] In this technical solution, tension detection devices 4 are respectively set for each spinning position of the steam drawing machine to detect the real-time tension value of the fiber bundle at each spinning position, thereby enabling real-time online detection of the fiber quality of the entire batch, so that operators can adjust the production line in a timely manner based on the detection results to ensure the quality of fiber batches.

[0039] In some embodiments, the first side surface is further provided with two sides respectively located on the first guide wheel 422 (see reference). Figure 1 The second guide roller 431 and the third guide roller 432 (as shown in the directions, i.e., the left and right sides) guide the fiber bundle 400 along its insertion and stretching direction (refer to the direction shown in the reference direction). Figure 1 The positions shown (i.e., from left to right) are sequentially tensioned on the first guide wheel 422, the second guide wheel 431, and the third guide wheel 432. (See attached image.) Figure 1As shown, the fiber bundle forms wrap angles on the first guide wheel 422, the second guide wheel 431, and the third guide wheel 432, respectively. The center of curvature of the wrap angle formed on the first guide wheel 422 is lower, the center of curvature of the wrap angle formed on the second guide wheel 431 is to the left, and the center of curvature of the wrap angle formed on the third guide wheel 432 is to the right. The telescopic rod 421 has an extended position and a retracted position. When the telescopic rod 421 is in the extended position, it applies a preset tension to the fiber bundle 400 in the stretched state via the first guide wheel 422. That is, the telescopic cylinder 42 applies a vertically upward tension to the fiber bundle. On 400, the tension is relatively constant during the normal steam drawing process of the fiber bundle 400. When the telescopic rod 421 is in the retracted position, the telescopic rod 421 pulls out part of the fiber bundle 400 that is in a broken state via the first guide wheel 422. That is, when the fiber bundle 400 breaks in the steam drawing machine for any reason, due to the tension applied by the telescopic rod 421 when it is in the extended position, the telescopic rod 421 will rise a certain distance, and the first guide wheel 422 will carry the broken fiber bundle on it up a certain distance, thereby pulling out the broken fiber in the steam drawing machine.

[0040] In this technical solution, the telescopic rod 421 applies a relatively constant tension to the fiber bundle 400 when it is in the extended position. When the fiber bundle 400 breaks in the steam drawing machine, that is, when the fiber bundle 400 is in a broken state, the telescopic rod 421 will rise from the extended position to the retracted position under the aforementioned tension. The broken fiber will be automatically and timely pulled out from the steam drawing machine by the first guide roller 422 that rises with it. This effectively prevents the broken fiber from clumping together under the action of hot steam in the steam drawing machine, blocking the fiber channel and making it difficult to clean. It can also prevent the fiber bundle from tangling on the drawing roller in a large area.

[0041] The aforementioned telescopic cylinder 42 can specifically be a commercially available mature structure such as a hydraulic cylinder or a pneumatic cylinder. As a preferred option, the aforementioned telescopic cylinder 42 is implemented using a pneumatic cylinder, which can directly utilize the workshop's pressurized air source, making cleaning convenient and cost-effective. It is understood that when the telescopic rod 421 is in the extended position, the pressure in the lower chamber formed by the piston of the telescopic rod 421 dividing the cylinder's internal cavity should be higher than the pressure in the upper chamber (see...). Figure 1 (As shown in the orientation) and the pressure difference remains stable, so as to ensure that it applies a relatively constant tension to the fiber bundle 400 during operation. At the same time, when the fiber bundle 400 breaks, the pressure difference is also used to switch the telescopic rod 421 from the extended position to the retracted position in time, so as to achieve the purpose of pulling the broken wire out of the steam drawing machine as soon as possible.

[0042] As a preferred embodiment, the broken fiber extraction device further includes a fiber suction gun 44. The negative pressure suction port of the fiber suction gun 44 is located on the traction path through which the fiber bundle 400 enters. It is assembled and connected to the mounting bracket 41 via the second mounting base 424. When the fiber bundle 400 breaks, it can promptly absorb the broken fiber bundle within it, preventing the broken fiber from tangling and knotting with other adjacent fiber bundles, which would be detrimental to other normally operating fiber bundles. The aforementioned fiber suction gun 44 can be a commonly used negative pressure fiber suction gun in the industry. This utility model does not intend to improve its specific structure, but only utilizes its negative pressure adsorption capability, that is, it can use a commercially available component that can form an adsorption force on the fiber bundle 400.

[0043] In one specific embodiment, the suction gun 44 is assembled on the first side surface, and the negative pressure suction port corresponds to the top surface area of ​​the first guide wheel 422 in the retracted position. See details below. Figure 3 As shown, by aligning the suction gun 44 with the top surface area of ​​the first guide wheel 422 connected to the free end of the telescopic rod 421 in the retracted position, the stability of the relative position between the broken filament and the suction gun 44 can be ensured. This prevents the broken filament from deviating significantly from the position of the negative pressure nozzle of the suction gun 44 due to a lack of necessary stretching tension, thus preventing effective adsorption.

[0044] In some embodiments, the displacement of the telescopic rod 421 from the extended position to the retracted position is L1 (not indicated in the figure), and the distance between the inlet of the inlet-side waste discharge chamber 501 of the steam stretcher and the outlet of the pressure reducing chamber 502 is L2 (e.g., ...). Figure 3 As shown), 2L1≥L2≥L1, thus ensuring that when the second guide wheel 431 rises with the telescopic rod 421 to switch to the retracted position, the broken wire can be completely extracted from the steam drawing machine without separating from the top surface of the first guide wheel 422. That is, the broken wire has a portion that wraps around the top surface area of ​​the first guide wheel 422, thereby ensuring the wire suction function of the wire suction gun 44.

[0045] In some embodiments, the tension detection device 4 further includes an electromagnetic wheel stop 46 (i.e., a wheel stop controlled by electronic control). The electromagnetic wheel stop 46 is assembled on the first side and is used to brake the second guide wheel 431 when the fiber bundle 400 breaks. The electromagnetic wheel stop 46 can be triggered to brake the second guide wheel 431, and the braking of the second guide wheel 431 is released after the suction gun 44 has been running for a preset time. At this time, it is understood that the suction gun 44 will further suck away the fiber bundle introduced by the second guide wheel 431 to prevent entanglement on the roller. In this technical solution, the activation of the electromagnetic wheel stop 46 is interlocked with the tension sensor, which can stop the upstream fiber bundle supply at the first moment of fiber bundle breakage, preventing large-area entanglement of the fiber bundle on the drafting roller 600. It is understood that the device is equipped with a corresponding controller, which can be integrated into the aforementioned stability judgment module 47.

[0046] The detection signal of the aforementioned tension sensor 45 is fed back to the stability judgment module 47, and the stability judgment module 47 compares the detection signal with the preset value (i.e., the preset tension value mentioned later). When the judgment result is that the real-time tension (i.e., the real-time tension value mentioned later) is lower than the preset tension value, it indicates that the yarn bundle is broken. At this time, the controller can send a corresponding control signal to control the suction gun 44 to run negative pressure adsorption, and at the same time control the electromagnetic stop wheel device 46 to run to brake the second guide wheel 431.

[0047] See details Figure 1 As shown, the lines connecting the projection points of the rotation centers of the first guide wheel 422, the second guide wheel 431, and the third guide wheel 432 onto the first side surface form an isosceles triangle with the rotation center of the first guide wheel 422 as its vertex. The rotation centers of the second guide wheel 431 and the third guide wheel 432 are respectively located on the same horizontal line to ensure horizontal guidance of the fiber bundle 400. In a specific embodiment, the aforementioned first guide wheel 422, second guide wheel 431, and third guide wheel 432 are all implemented using guide wheels of the same size and specifications.

[0048] According to an embodiment of the present invention, a control method for the steam drawing machine fiber bundle operation status monitoring device as described above is also provided, comprising the following steps:

[0049] Obtain the real-time tension value Ts (in cN or N) of the fiber bundles at each spinning position of the steam drawing machine;

[0050] Determine the relationship between the real-time tension value Ts and the first preset tension value Ty1 (in cN or N);

[0051] When Ty1≥Ts≥0.97Ty1, it indicates that the fiber bundle stability can meet the requirements of product quality, and the fiber bundle stretching operation is normal. At this time, the long-range stability of the fiber bundle corresponding to each spinning position is further obtained, and / or the stability of the fiber bundle at each different spinning position of the steam stretching machine is obtained, so as to quantitatively evaluate the stability of the fiber bundle.

[0052] When 0.9Ty1 < Ts < 0.97Ty1, it indicates that the fiber bundle is in an abnormal operating state. There may be relatively serious problems such as fuzzy fibers, partial fiber breakage, and partial strand breakage. The fiber bundle is unstable and an alarm should be issued in time to prompt the operator to carry out maintenance. The aforementioned maintenance includes, but is not limited to, checking whether the process settings are accurate and carrying out necessary inspections or repairs on the upstream and downstream related equipment of the production line. After eliminating the factors that cause the fiber bundle to produce the aforementioned abnormalities, production can be resumed to prevent waste of materials caused by abnormal operation.

[0053] In some embodiments, obtaining the long-range stability of the fiber bundles corresponding to each spinning position includes:

[0054] Obtain N real-time tension values ​​within a preset time interval at the same spinning position, and calculate the first average value Taverage1 and the first standard deviation T1 of the N real-time tension values. 标准偏差1 Calculate the stability dispersion coefficient CV of this fiber bundle. 单束 =(T 标准偏差1 / T 平均值1 ()×100%, N is not less than 50. In a specific embodiment, measured tension values ​​are selected at 10-second intervals, and the number of selected values ​​is 50. The average value and standard deviation of the 50 measured tension values ​​are calculated, and the fiber long-range stability dispersion coefficient is calculated. A large fiber long-range stability dispersion coefficient indicates that the tension data is also highly dispersed, indicating that the fiber stability is relatively poor. A small fiber long-range stability dispersion coefficient indicates that the tension data is also highly dispersed, indicating that the fiber stability is relatively good. Specifically, the dispersion coefficient of N real-time tension values ​​at intervals characterizes the fiber long-range stability.

[0055] When the stability dispersion coefficient CV of the fiber bundle 单束 When the coefficient of variation (CV) is ≤0.8, the stability of the fiber bundle meets the product quality requirements; when the stability dispersion coefficient (CV) of the fiber bundle is ≤0.8, the stability of the fiber bundle meets the product quality requirements. 单束 The fiber exhibits the best long-range stability when the coefficient of performance is ≤0.3; when 0.3 < CV, the stability is better. 单束 When ≤0.6, the fiber long-range stability is good; when 0.6<CV 单束When the coefficient of variation is ≤0.8, the fiber's long-range stability is generally poor. By determining the fiber's long-range variation coefficient, the fibers can be graded for processing, allowing downstream users to select fibers with different variation coefficients for post-processing based on their carbon fiber quality requirements. This stability variation coefficient meets the requirements of polyacrylonitrile fibers used in aerospace and other fields.

[0056] Alternatively, obtaining the stability of the fiber bundles at different spinning positions of the steam drawing machine includes: obtaining M real-time tension values ​​of the corresponding fiber bundles at each different spinning position within a preset interval time period in a second preset time period, wherein the number of spinning positions of the steam drawing machine is a, and calculating the second average value T of the M×a real-time tension values. 平均值2 and the second standard deviation T 标准偏差2 Calculate the stability dispersion coefficient CV of the total fiber bundle for all said spinning positions. 所有纺位 =(T 标准偏差2 / T 平均值2 ()×100%, M is not less than 20. In a specific embodiment, within the same time period, measured tension values ​​at different spinning positions are selected at 10-second intervals, with 20 values ​​selected for each spinning position. The average value and standard deviation of all selected measured tension values ​​are calculated, and the fiber stability dispersion coefficient at different spinning positions is calculated. Specifically, when the fiber stability dispersion coefficient CV of all spinning positions is... 所有纺位 When the overall fiber bundle stability is ≤0.9, the overall fiber bundle stability meets product quality requirements. When the stability dispersion coefficient CV of all fibers at each spinning position... 所有纺位 When ≤0.4, the fiber stability is best at all spinning positions; when 0.4<CV 所有纺位 When ≤0.7, the fiber stability of all spinning positions is good; when 0.7<CV 所有纺位 When the coefficient of variation is ≤0.9, the stability of fibers at all spinning positions is generally moderate. By judging the stability dispersion coefficient of the overall fiber bundle, fibers at different spinning positions can be graded and processed. Downstream users can select fibers with different dispersion coefficients for post-processing according to the carbon fiber quality requirements. This stability dispersion coefficient meets the requirements of polyacrylonitrile fibers used in aerospace and other fields.

[0057] In some embodiments, when the telescopic rod 421 of the steam drawing machine fiber bundle operation status monitoring device has an extended position and a retracted position, and includes a suction gun 44 and an electromagnetic stop wheel 46, when Ts≤0.9Ty1, it indicates that the fiber bundle is severely broken, or even the entire fiber bundle is broken. At this time, the telescopic rod 421 is controlled to switch from the extended position to the retracted position, the suction gun 44 is controlled to operate synchronously, and the electromagnetic stop wheel 46 is controlled to brake the second guide wheel 431. The telescopic rod 421 pulls out part of the fiber bundle 400 in the broken state via the first guide wheel 422, that is, in the fiber bundle When a fiber breakage occurs in the steam drawing machine for any reason, the tension applied by the telescopic rod 421 when it is in the extended position will cause the telescopic rod 421 to rise a certain distance. The first guide wheel 422 will carry the broken fiber bundle on it to rise a certain distance, thereby pulling out the broken fiber in the steam drawing machine. This effectively prevents the broken fiber from clumping together under the action of hot steam in the steam drawing machine, blocking the fiber channel, and making it difficult to clean. After the suction gun 44 has been running for a preset time, the electromagnetic stop wheel 46 is controlled to release the brake on the second guide wheel 431, so that the suction gun 44 can further suck away the fiber bundle introduced by the second guide wheel 431, preventing it from getting tangled in the roller. It is understandable that when Ts≤0.9Ty1, there is a situation where the fiber bundle in a spinning position is not completely broken. In this case, the retraction force of the telescopic rod 421 should be large enough to ensure that the corresponding fiber bundle can be pulled and broken, thereby achieving the subsequent purpose of fiber suction. In a more specific embodiment, when 0.1Ty1≤Ts≤0.9Ty1, considering that the telescopic rod is subjected to a large force during the retraction process, it is necessary to first cut the corresponding fiber at the inlet side of the steam drawing machine, and then control the telescopic rod 421 to switch from the extended position to the retracted position, and control the fiber suction gun 44 to operate synchronously to absorb the broken fiber bundle, preventing the broken fiber from interacting with other adjacent fibers. When fiber bundles become entangled and knotted, it can negatively impact other normally operating fiber bundles. To effectively prevent large-area entanglement of fiber bundles on the drafting roller, this technical solution first uses manual intervention to cut the fiber bundles, reducing the stress on the telescopic rod and lowering the retraction drive power. When 0 ≤ Ts < 0.1Ty1, ​​indicating that the fiber bundle is almost completely broken, the telescopic rod 421 is switched from the extended position to the retracted position. The suction gun 44 operates synchronously, and the electromagnetic stop wheel 46 brakes the second guide wheel 431. The telescopic rod 421, via the first guide wheel 422, extracts a portion of the fiber bundle 400 that is in a broken filament or strand state. The suction gun 44 is also activated promptly to attract the broken filament bundle, preventing it from becoming entangled and knotted with other adjacent fiber bundles, thus avoiding negative impacts on other normally operating fiber bundles.This effectively prevents broken fibers from clumping together under the action of hot steam in the steam drafting machine, blocking the fiber channels and making them difficult to clean. It also prevents large-area entanglement of fiber bundles on the drafting rollers.

[0058] See Figure 1 and Figure 3 As shown in the figure, a spinning position in a steam drafting machine (introduced from the left side of the fiber bundle and led out from the right side) is illustrated. See details... Figure 1 Each spinning station, from the fiber bundle inlet side to the outlet side, consists of a waste discharge chamber 501, a pressure reducing chamber 502, a steam drawing chamber 503, and another waste discharge chamber 501. The steam drawing chamber 503 is connected to a steam inlet pipe 504 that is controllably connected to an external steam source. A solenoid valve 5041, a filter 5042, and a ball valve 5043 are connected in series on the steam inlet pipe 504. The opening and closing of the solenoid valve 5041 controls whether steam from the external steam source enters the corresponding steam drawing chamber 503. In a preferred embodiment, when the electromagnetic stop wheel 46 operates to brake the second guide wheel 431, the controller also controls the solenoid valve 5041 to cut off steam from entering the steam drawing chamber 503. This facilitates the operator's maintenance of the pressure reducing components (generally labyrinth seals) in the pressure reducing chamber 502, preventing steam from entering the pressure reducing chamber 502 during maintenance and avoiding potential injury to maintenance personnel.

[0059] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0060] 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, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A device for monitoring the operating status of fiber bundles in a steam drawing machine, characterized in that, The device includes a tension detection device (4) and a steam drafting machine. The tension detection device (4) is configured to correspond to the target spinning position of the steam drafting machine. The tension detection device (4) includes a mounting bracket (41). A telescopic cylinder (42) is assembled on the first side of the mounting bracket (41). A first guide wheel (422) is provided on the free end of the telescopic rod (421) of the telescopic cylinder (42). The fiber bundle (400) is tensioned on the first guide wheel (422). The tension detection device (4) also includes a tension sensor (45) and a stability judgment module (47). The first guide wheel (422) 2) The stability judgment module (47) is configured to determine the long-range stability of the fiber bundle (400) tensioned on the first guide wheel (422) based on the real-time tension value detected by the tension sensor (45) and the free end of the telescopic rod (421) via the tension sensor (45); the first side is also provided with a second guide wheel (431) and a third guide wheel (432) respectively located on both sides of the first guide wheel (422), and the fiber bundle (400) is tensioned sequentially on the first guide wheel (422), the second guide wheel (431) and the third guide wheel (432) along its insertion and stretching direction. On the three guide rollers (432), the fiber bundles form wrap angles on the first guide roller (422), the second guide roller (431), and the third guide roller (432), respectively. The center of curvature of the wrap angle formed on the first guide roller (422) is lower, the center of curvature of the wrap angle formed on the second guide roller (431) is to the left, and the center of curvature of the wrap angle formed on the third guide roller (432) is to the right. The telescopic rod (421) has an extended position and a retracted position. When the telescopic rod (421) is in the extended position, the telescopic rod (421) applies a preset tension via the first guide roller (422). When the telescopic rod (421) is in the retracted position, the telescopic rod (421) pulls out part of the fiber bundle (400) in the broken state via the first guide wheel (422); the tension detection device (4) also includes a suction gun (44), the negative pressure suction port of the suction gun (44) is located on the fiber bundle (400) entering the traction path, the suction gun (44) is assembled on the first side, and the negative pressure suction port corresponds to the top surface area of ​​the first guide wheel (422) in the retracted position.

2. The steam drawing machine fiber bundle operation status monitoring device according to claim 1, characterized in that, The tension detection device (4) has multiple units, and each tension detection device (4) is set up in a corresponding manner to each spinning position of the steam drawing machine. The stability judgment module (47) is also configured to judge the stability of the fiber bundle (400) at different spinning positions based on the real-time tension value detected by each tension sensor (45).

3. The steam drawing machine fiber bundle operation status monitoring device according to claim 1, characterized in that, The displacement of the telescopic rod (421) from the extended position to the retracted position is L1, and the distance between the inlet of the waste discharge chamber (501) on the inlet side of the steam stretcher and the outlet of the pressure reducing chamber (502) is L2, 2L1≥L2≥L1.

4. The fiber bundle operation status monitoring device for a steam drawing machine according to claim 1, characterized in that, The tension detection device (4) further includes an electromagnetic wheel stop (46), which is assembled on the first side. The electromagnetic wheel stop (46) is used to brake the second guide wheel (431) when the fiber bundle (400) breaks. The electromagnetic wheel stop (46) can be triggered to brake the second guide wheel (431) and release the brake on the second guide wheel (431) after the suction gun (44) has been running for a preset time.

5. A control method for a steam drawing machine fiber bundle operation status monitoring device as described in any one of claims 1 to 4, comprising the following steps: Obtain the real-time tension value Ts of the fiber bundles at each spinning position of the steam drawing machine; Determine the magnitude relationship between the real-time tension value Ts and the first preset tension value Ty1; When Ty1≥Ts≥0.97Ty1, the long-range stability of the fiber bundles corresponding to each spinning position is obtained, and / or, the stability of the fiber bundles at each different spinning position of the steam drawing machine is obtained. When 0.9Ty1 < Ts < 0.97Ty1, an alarm message is issued to prompt the operator to perform maintenance.

6. The control method according to claim 5, characterized in that, Obtaining the long-range stability of the fiber bundles corresponding to each spinning position includes: Obtain N real-time tension values ​​within a preset time interval at the same spinning position, and calculate the first average value Taverage1 and the first standard deviation T1 of the N real-time tension values. 标准偏差1 Calculate the stability dispersion coefficient CV of this fiber bundle. 单束 = (T 标准偏差1 / T 平均值1 ) × 100%, N is not less than 50; or, Obtaining the stability of the fiber bundles at different spinning positions in the steam drawing machine includes: M real-time tension values ​​are obtained from the fiber bundles corresponding to different spinning positions within a preset time interval in a second preset time period. The number of spinning positions in the steam drawing machine is a. The second average value T of the M×a real-time tension values ​​is calculated. 平均值2 and the second standard deviation T 标准偏差2 Calculate the stability dispersion coefficient CV of the total fiber bundle for all said spinning positions. 所有纺位 = (T 标准偏差2 / T 平均值2 ) × 100%, M is not less than 20.

7. The control method according to claim 5, characterized in that, When the telescopic rod (31) of the steam drawing machine fiber bundle operation status monitoring device has an extended position and a retracted position, and includes a suction gun (44) and an electromagnetic wheel stopper (46), when Ts≤0.9Ty1, the telescopic rod (31) is controlled to switch from the extended position to the retracted position, the suction gun (44) is controlled to run synchronously, the electromagnetic wheel stopper (46) is controlled to run and brake the second guide wheel (431), and after the suction gun (44) has run for a preset time, the electromagnetic wheel stopper (46) is controlled to release the brake on the second guide wheel (431).

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