Method for online detecting whether movement of three-blade shifting fork is abnormal or not

Abstract

The invention belongs to the technical field of polyester filaments, and discloses a method for on-line detection of abnormal movement of a three-leaf shifting fork, which comprises the following steps: mounting a camera and a stroboscopic light source on a winding head, mounting a friction roller and a spindle below the three-leaf shifting fork, mounting a paper tube on the spindle, and winding tows on the paper tube to form a spinning cake. The spinning cake is in contact with the friction roller in the winding process and the rotating directions of the spinning cake and the friction roller are opposite; marking points I and II are arranged on the inner sides of the friction rollers corresponding to the two ends of the travel of the tow, and the endpoints, close to the marking points I and II, of the two ends of the travel of the tow are marked as endpoints I and II respectively; in the selected time period, the tows move from the mark point I and the mark point II to the end point I and the end point II and then return to the mark point I and the mark point II, the camera takes frames to obtain the number of frames of photos, the number of frames is counted to obtain N1 and N2, and whether the three-blade shifting fork moves normally or not is judged according to the deviation between N1 and N2. Whether the three-blade shifting fork moves abnormally or not can be detected in real time, and the difference of the number of winding turns at the two ends of a spinning cake is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyester filaments and relates to a method for on-line detecting whether the movement of a three-leaf fork is abnormal. Background Art

[0002] The high-speed winding machine is an important device in the production process of polyester filaments. Its main components include a traversing device, a switching device, a threading device, etc. Among them, the traversing device makes the filament bundle move reciprocally to ensure that the filament bundle is evenly laid on the paper tube, which is a key component affecting the winding forming.

[0003] Currently, the traversing device can be divided into: the rabbit-head type and the fork type according to the traversing method.

[0004] The rabbit-head type traversing device uses a grooved roller with a spiral groove on the cylindrical surface as a cylindrical cam. Through the direct drive of the motor, the grooved roller rotates and drives the rabbit-head slider embedded in the groove to move left and right reciprocally to complete the wire guiding process. However, when producing polyester drawn yarn, due to the extremely high winding speed, often exceeding 4000 m / min, this high-speed operation state will exacerbate the wear of the rabbit-head slider, thereby affecting the quality of the winding forming. Therefore, when producing polyester drawn yarn, it is more inclined to use a fork type winding machine.

[0005] The fork type traversing device is composed of two groups of three-leaf fork pieces stacked up and down. These two groups of fork pieces rotate clockwise and counterclockwise respectively, and drive the filament bundle to move reciprocally through their rotational movement. However, after long-term use, the fork may have wear or slight deformation. This wear or deformation will destroy the parallelism of the three-leaf fork relative to the installation reference surface, and thus have an adverse effect on the forming of the silk cake. Specifically, one end winds more filaments and the other end winds less filaments. The end with more wound filaments is under greater pressure, resulting in a higher temperature, which is equivalent to increasing the setting temperature of the filament bundle after winding, further increasing its crystallinity, and ultimately resulting in a phenomenon of being too light or even unable to be dyed during dyeing, seriously affecting the product quality and production efficiency. Therefore, a method is needed to monitor whether there is wear or slight deformation of the fork during the production and processing process.

[0006] To solve the above problems, a patent application with the publication number CN101462661A discloses a control method for preventing color difference in filament dyeing caused by problems with the fork of a winding machine. This method involves periodically or continuously monitoring the temperatures of the two shoulders of a filament roll running at high speed during the production process, comparing the larger value of the temperatures of the two shoulders measured at the same time with the standard normal filament roll temperature range, and determining that the fork of this filament roll is abnormally likely to cause poor dyeing if the range is exceeded. However, since the temperatures of the two shoulders of the tested filament roll are greatly affected by the winding speed, the ambient temperature, and which spindle the filament is on, it is very easy for the outermost spindle to have abnormal fork movement but the package temperature remains basically unchanged, thus leading to misjudgment.

[0007] Therefore, it is of great significance to study a method for online detecting whether the movement of the three-leaf fork is abnormal to solve the above problems. Summary of the Invention

[0008] The object of the present invention is to solve the problems existing in the prior art and provide a method for online detecting whether the movement of the three-leaf fork is abnormal.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] A method for online detecting whether the movement of a three - leaf fork is abnormal. A three - leaf fork is installed on the traversing box of a winding head. A friction roller is installed below the three - leaf fork, and a spindle is provided below the friction roller. A paper tube is installed on the spindle, and a tow is wound on the paper tube to form a cake. During the winding process, the cake contacts the friction roller and the rotation directions of the cake and the friction roller are opposite. A camera and a stroboscopic light source are installed on the wire separating plate of the winding head. Both the camera and the stroboscopic light source face the cake to keep the cake at the center of the imaging photo. Denote the installation positions of the camera and the stroboscopic light source as point A and point A' respectively. The mid - point of any two endpoints along the length direction (i.e., the axial direction of the paper tube) on the forming surface of the cake is point B. Point A and the central axis of the friction roller are at the same height. Point A' is directly above point A, and the distance between point A and point A' is 1 cm. The connection line between point A and point B is parallel to the end face of the cake. The rotation of the three - leaf fork drives the tow to move back and forth on the forming surface of the cake. The rotation frequency of the three - leaf fork changes every 10 - 20 s. Control the frequency of the stroboscopic light source to be equal to and synchronized with the frame - taking frequency of the camera. Otherwise, the taken frame photos are unclear and cannot be analyzed. Marking points are set on the inner sides of the friction rollers corresponding to both ends of the travel of the tow, denoted as marking point Ⅰ and marking point Ⅱ respectively. The two endpoints of the travel of the tow near marking point Ⅰ and marking point Ⅱ are denoted as endpoint Ⅰ and endpoint Ⅱ respectively. During the selected time period, count the number of frames of the photos obtained by the camera when the tow moves from marking point Ⅰ to endpoint Ⅰ and then returns to marking point Ⅰ to get N1. At the same time, count the number of frames of the photos obtained by the camera when the tow moves from marking point Ⅱ to endpoint Ⅱ and then returns to marking point Ⅱ to get N2. If the deviation between N1 and N2 is greater than 5%, it indicates that the movement of the three - leaf fork is abnormal. Otherwise, it indicates that the movement of the three - leaf fork is normal.

[0011] The selected time period refers to the period from the start of one change in the rotation frequency of the three - leaf fork to before the next change.

[0012] The frequency of the stroboscopic light source flashing = the rotation frequency of the three - leaf fork × 3 - N. The reason for setting the frequency of the stroboscopic light source flashing to 3 times the rotation frequency of the three - leaf fork - N is that in this invention, for a three - leaf fork, when the fork rotates one circle, it is equivalent to the tow rotating back and forth 3 times on the forming end face of the cake. If the frequency of the stroboscopic light source flashing is set to 3 times the frequency of the three - leaf fork, it is equivalent to sampling at the same position each time. Therefore, in the actual analysis process, it is set to 3 times - N (Hz), which can make the sampling position deviate slightly. The rotation frequency of the three - leaf fork is 7.3 - 7.8 Hz, and N = 0.04989 - 0.09954 Hz. In this way, a slow and continuous dynamic picture of the tow during one round - trip movement can be obtained, and by analyzing the pictures obtained during one round - trip movement, it can be determined whether the movement of the tow is normal.

[0013] The specific parameters involved in the calculation and derivation process of N are shown in the following table:

[0014]

[0015]

[0016] N = 1 / T - 1 / (T + T2)

[0017] = 1 / (1 / (3F)) - 1 / (1 / (3F) + L2 / V)

[0018] = 3F - 1 / (1 / (3F) + T / M)

[0019] = 3F - 1 / (1 / (3F) + T / (3F*T1))

[0020] = 3F - 1 / (1 / (3F) + (1 / 3F) / (3F*T1))

[0021] = 3F - 1 / [1 / (3F) + 1 / (9F 2 *T1)];

[0022] The value of N is directly proportional to the frequency of the three - lobe fork and inversely proportional to the change time of the three - lobe fork frequency. Therefore, when the frequency of the three - lobe fork is the maximum and the change time of the three - lobe fork frequency is the minimum, the value of N is the maximum; conversely, the value of N is the minimum.

[0023] The frequency range of the three - lobe fork is 7.3 - 7.8H Z , and the change time of the fork frequency is 10 - 20s. Therefore, the finally calculated value range of N is 0.04989 - 0.09954Hz.

[0024] As a preferred technical solution:

[0025] As described above, a method for online detecting whether the movement of a three - lobe fork is abnormal realizes online detection of whether the movement of the three - lobe fork is abnormal by installing a fork synchronous video detection system on a winding head. The fork synchronous video detection system includes a stroboscopic light source, a camera, a stroboscopic light source frequency modulation control module, a variable - frame imaging control module, a fork frequency converter, a parameter control main board, a display, and an imaging analysis host. The camera and the stroboscopic light source are installed on the wire separating plate of the winding head. Each bobbin corresponds to a group of camera and stroboscopic light source. The stroboscopic light source is connected to the stroboscopic light source frequency modulation control module, the camera is connected to the variable - frame imaging control module, the fork frequency converter is connected to the fork motor, the fork motor drives the three - lobe fork to rotate through a transmission device, the parameter control main board is connected to the fork frequency converter, the stroboscopic light source frequency modulation control module, and the variable - frame imaging control module simultaneously through a 485 communication protocol, and the camera, the imaging analysis host, and the display are connected in sequence.

[0026] The parameter control main board calculates the set forming angle parameter (the forming angle parameter constantly changes, which is an anti-overlapping wire mechanism in the forming angle control program. The time interval for slight changes in the forming angle according to the manufacturer's settings is 10 - 20 seconds) into a frequency signal, and then transmits it to the fork frequency converter through the 485 communication protocol. At the same time, it is also transmitted to the stroboscopic light source frequency modulation control module and the variable frame imaging control module. The stroboscopic light source frequency modulation control module controls the stroboscopic light source to perform stroboscopic according to the received frequency signal, and the variable frame imaging control module controls the camera to capture frames according to the received frequency and mark each frame of the photo (mark the current frequency and frame capture time. In the subsequent analysis process, all photos with the same fork frequency within a continuous time will be analyzed, and marks will be made on these photos). The captured frames are transmitted to the imaging analysis host for image synthesis and processing, and a dynamic image is displayed on the monitor. At the same time, it can be judged whether there are hard or soft wires in a certain cake: If the winding is abnormal, that is, one end winds more wires (longer time, more photo frames), and the other end winds less (shorter time, fewer photo frames). At the end with more winding, it is equivalent to more superposition of the wire bundle on the paper tube. Since the contact pressure is constant, the diameter of this end with more winding grows faster. However, the friction roller is parallel to the surface of the cake for extrusion, resulting in a greater extrusion force on this end with more winding. Thus, the cake wound on the paper tube is relatively harder (the extrusion force and superposition force are increased). And under the high-speed operation of the winding machine (speed above 4000 m / min), the wire bundle at this end is under the action of multiple forces such as superposition force, centripetal extrusion force, and contact pressure, showing extrusion deformation (when severe, there are obvious changes in the fiber cross-sectional diagram), increasing its crystallinity, resulting in lighter or even no dyeing. At the same time, because there are more superposed wire bundles, the temperature at this end is relatively high, which is equivalent to increasing the setting temperature of the wire bundle after winding, further increasing its crystallinity, and thus affecting the dyeing performance. And for the end with less winding (shorter time, fewer photo frames), the cake is relatively softer, and the principle is opposite to the above.

[0027] As described above, a method for on-line detecting whether the movement of a three-blade fork is abnormal. The number of cakes on the winding head is 8 - 16. The 8 - 16 cakes respectively correspond to 8 - 16 groups of cameras and stroboscopic light sources. The 8 - 16 cameras are simultaneously connected to the variable frame imaging control module, and the 8 - 16 stroboscopic light sources are simultaneously connected to the stroboscopic light source frequency modulation control module.

[0028] As described above, a method for on-line detecting whether the movement of a three-blade fork is abnormal. The thickness of the cake is 75 - 95 mm, and the diameter of the cake is 370 - 375 mm.

[0029] An online method for detecting whether the movement of a three-lobe fork is abnormal, with a winding speed of 4000 - 5200 m / min. The winding speed of FDY is usually around 4500 m / min. Different varieties and specifications have different suitable spinning conditions, and the winding speed will vary, ranging from 4000 m / min to 5200 m / min.

[0030] An online method for detecting whether the movement of a three-lobe fork is abnormal, where marking point Ⅰ and marking point Ⅱ are set 10 - 24 mm inside the corresponding friction rollers at both ends of the travel of the tow. The present invention detects the difference in winding at both ends of the cheese, so the marking points must correspond to both ends. To obtain a more accurate comparison result, the distance between the marking point and its corresponding end point cannot be too small. According to the number of frame-taking photos being no less than 30, it is calculated that the distance between the marking point and the corresponding end point is not less than 1 cm, and the maximum is half of the cheese thickness. However, the surfaces of the friction rollers in contact with the cheese surface near both ends are designed with smooth surfaces, and a part in the middle is designed with a rough surface (this design of the friction roller is a prior art). Such a design is mainly to ensure that the winding of the tow at both ends is basically the same as that in the middle. If the surfaces of the cheese in contact with the friction rollers are all smooth or all rough, there will be a situation where there is much more winding in the middle and much less at both ends. The present invention mainly detects whether there are hard and soft filaments in the winding near both ends of the cheese, so based on the distance where the surface of the cheese is in contact with the friction roller with a smooth surface, when the cheese thickness is 75 mm, the contact distance with the smooth surface is 20 mm, and when the cheese thickness is 95 mm, the contact distance with the smooth surface is 24 mm. Therefore, the distance between the marking point and the end point is 10 - 24 mm.

[0031] Beneficial effects:

[0032] In the present invention, a camera and a stroboscopic light source are installed on the wire separating plate of the winding head. According to the interval during which the rotation frequency of the three-lobe fork changes once, the marking points inside the corresponding friction rollers at both ends of the travel of the tow are obtained in real time and compared to determine whether there is an abnormality in the movement of the three-lobe fork, so as to detect in real time whether there is a difference in the number of winding turns of the cheese at both ends during the winding process, and avoid affecting the quality of the tow on the cheese. Description of the drawings

[0033] Figure 1 It is the right view of the device used for the method of the present invention to online detect whether the movement of the three-lobe fork is abnormal;

[0034] Figure 2 It is the schematic diagram of the device used for the method of the present invention to online detect whether the movement of the three-lobe fork is abnormal;

[0035] Figure 3 It is the schematic diagram of the device used for the method of the present invention to online detect whether the movement of the three-lobe fork is abnormal in the use state;

[0036] Among them, 1 - traversing box, 2 - three - blade fork, 3 - friction roller, 4 - bobbin, 5 - spindle, 6 - stroboscopic light source, 7 - camera, 8 - wire separating plate, 9 - connecting line between point A and point B, 10 - bobbin center line, 11 - endpoint Ⅰ, 12 - endpoint Ⅱ, 13 - marking point Ⅰ, 14 - marking point II, 15 - paper tube, 16 - tow. Specific embodiments

[0037] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0038] A method for online detecting whether the movement of a three - blade fork is abnormal, as Figures 1 to 3 shown, a three - blade fork 2 is installed on the traversing box 1 of the winding head. At the same time, an online detection of whether the movement of the three - blade fork 2 is abnormal is realized by installing a fork synchronous video detection system on the winding head. A friction roller 3 is installed below the three - blade fork 2, and a spindle 5 is provided below the friction roller 3. A paper tube 15 is installed on the spindle 5. The tow 16 is wound on the paper tube 15 to form a bobbin 4 with a thickness of 75 - 95 mm and a diameter of 370 - 375 mm. During the winding process, the bobbin 4 is in contact with the friction roller 3 and the rotation directions of the bobbin 4 and the friction roller 3 are opposite; among them, the number of bobbins 4 on the winding head is 8 - 16 in total, and the winding speed is 4000 - 5200 m / min;

[0039] The fork synchronous video detection system includes a stroboscopic light source 6, a camera 7, a stroboscopic light source frequency modulation control module, a variable - frame imaging control module, a fork frequency converter, a parameter control main board, a display, and an imaging analysis host;

[0040] The camera 7 and the stroboscopic light source 6 are installed on the wire separating plate 8 of the winding head. Both the camera 7 and the stroboscopic light source 6 face the bobbin 4 and are on the bobbin center line 10. Denote the installation positions of the camera 7 and the stroboscopic light source 6 as point A and point A' respectively. The mid - point of any two endpoints along the length direction on the forming surface of the bobbin 4 is point B. Point A and the central axis of the friction roller 3 are at the same height. Point A' is directly above point A, and the distance between point A and point A' is 1 cm. The connecting line 9 between point A and point B is parallel to the end face of the bobbin 4;

[0041] 8 to 16 bobbins 4 respectively correspond to 8 to 16 groups of cameras 7 and stroboscopic light sources 6. The 8 to 16 cameras 7 are simultaneously connected to the variable frame imaging control module, and the 8 to 16 stroboscopic light sources 6 are simultaneously connected to the stroboscopic light source frequency modulation control module. The fork frequency converter is connected to the fork motor, and the fork motor drives the three-lobe fork 2 to rotate through a transmission device. The parameter control main board is simultaneously connected to the fork frequency converter, the stroboscopic light source frequency modulation control module, and the variable frame imaging control module through the 485 communication protocol. The camera 7, the imaging analysis host, and the display are connected in sequence;

[0042] The rotation of the three-lobe fork 2 drives the tow 16 to move back and forth on the forming surface of the bobbin 4. The rotation frequency of the three-lobe fork 2 changes once every 10 - 20 s. The frequency of the stroboscopic light source 6 flashing is controlled to be equal to the frame-taking frequency of the camera 7. Marking points are set 10 - 24 mm inside the inner sides of the friction rollers 3 corresponding to both ends of the travel of the tow 16, and are respectively denoted as marking point Ⅰ 13 and marking point Ⅱ 14. The two end points of the travel of the tow 16 near marking point Ⅰ 13 and marking point Ⅱ 14 are respectively denoted as end point Ⅰ 11 and end point Ⅱ 12. During the selected time period (that is, from the start of one change in the rotation frequency of the three-lobe fork 2 to before the next change), the number of frames of the photos obtained by the camera 7 when the tow 16 moves from marking point Ⅰ 13 to end point Ⅰ 11 and then returns to marking point Ⅰ 13 is counted to obtain N1. At the same time, the number of frames of the photos obtained by the camera 7 when the tow 16 moves from marking point Ⅱ 14 to end point Ⅱ 12 and then returns to marking point Ⅱ 14 is counted to obtain N2. If the deviation between N1 and N2 is greater than 5%, it indicates that the movement of the three-lobe fork 2 is abnormal; otherwise, it indicates that the movement of the three-lobe fork 2 is normal. Among them, the frequency of the stroboscopic light source flashing = the rotation frequency of the three-lobe fork × 3 - N, the three-lobe fork frequency is 7.3 - 7.8 Hz, and N = 0.04989 - 0.09954 Hz.

[0043] To verify whether the above method for online detecting whether the movement of the three-lobe fork is abnormal can monitor abnormalities online, the above method is used for example verification as follows:

[0044] Example 1

[0045] The above method for online detecting whether the movement of the three-lobe fork is abnormal is used for online monitoring, where: the winding speed is 4000 m / min, the number of bobbins on the winding head is 16 in total, the number of cameras and stroboscopic light sources is 16 groups, the thickness of the wound bobbin is 75 mm, and the diameter is 375 mm;

[0046] The interval time for one change in the rotation frequency of the three-lobe fork is 10 s. Marking point Ⅰ and marking point Ⅱ are set 10 mm inside the inner sides of the friction rollers corresponding to both ends of the travel of the tow, and the range of the three-lobe fork frequency change is 7.3 - 7.5 Hz;

[0047] During the process that the three - leaf fork rotates to drive the tow to move back and forth on the cake forming surface, when the frequency of the three - leaf fork starts to change to 7.3 Hz, it is taken as the monitoring starting point. The next frequency of the three - leaf fork will change from 7.3 Hz to 7.35 Hz. When the next frequency of the three - leaf fork starts to change to 7.35 Hz, it is taken as the monitoring ending point. During this time period, N is 0.09955 Hz. And during this time period, the number of frames of the photos obtained by taking frames of the camera for the process that the tow moves from marking point Ⅰ to end point Ⅰ and then returns to marking point Ⅰ is counted, and N1 is 28 frames. At the same time, the number of frames of the photos obtained by taking frames of the camera for the process that the tow moves from marking point Ⅱ to end point Ⅱ and then returns to marking point Ⅱ is counted, and N2 is 30 frames. Finally, through calculation, it is known that the deviation between N1 and N2 is 7.14%, which indicates that the movement of the three - leaf fork is abnormal.

[0048] Example 2

[0049] The above - mentioned method for on - line detecting whether the movement of the three - leaf fork is abnormal is used for on - line monitoring, where: the winding speed is 4300 m / min, the number of cakes on the winding head is 12 in total, the number of cameras and stroboscopic light sources is 12 groups, the thickness of the wound cake is 80 mm, and the diameter is 373 mm;

[0050] The interval time for the frequency of the three - leaf fork to change once is 13 s. Marking point Ⅰ and marking point Ⅱ are set 14 mm inside the corresponding friction rollers at both ends of the stroke of the tow. The frequency change range of the three - leaf fork is 7.3 - 7.6 Hz;

[0051] During the process that the three - leaf fork rotates to drive the tow to move back and forth on the cake forming surface, when the frequency of the three - leaf fork starts to change to 7.395 Hz, it is taken as the monitoring starting point. The next frequency of the three - leaf fork will change from 7.395 Hz to 7.394 Hz. When the next frequency of the three - leaf fork starts to change to 7.394 Hz, it is taken as the monitoring ending point. During this time period, N is 0.07666 Hz. And during this time period, the number of frames of the photos obtained by taking frames of the camera for the process that the tow moves from marking point Ⅰ to end point Ⅰ and then returns to marking point Ⅰ is counted, and N1 is 50 frames. At the same time, the number of frames of the photos obtained by taking frames of the camera for the process that the tow moves from marking point Ⅱ to end point Ⅱ and then returns to marking point Ⅱ is counted, and N2 is 51 frames. Finally, through calculation, it is known that the deviation between N1 and N2 is 2.00%, which indicates that the movement of the three - leaf fork is normal.

[0052] Example 3

[0053] The above - mentioned method for on - line detecting whether the movement of the three - leaf fork is abnormal is used for on - line monitoring, where: the winding speed is 4600 m / min, the number of cakes on the winding head is 12 in total, the number of cameras and stroboscopic light sources is 12 groups, the thickness of the wound cake is 85 mm, and the diameter is 372 mm;

[0054] The interval time for one change in the rotation frequency of the three - leaf fork is 15 s. Marking point Ⅰ and marking point Ⅱ are set 18 mm inside the corresponding friction rollers at both ends of the travel of the tow. The frequency change range of the three - leaf fork is 7.3 - 7.6 Hz;

[0055] During the process where the rotation of the three - leaf fork drives the tow to move back and forth on the cake - forming surface, when the frequency of the three - leaf fork starts to change to 7.592 Hz, it is used as the monitoring starting point. The next frequency of the three - leaf fork will change from 7.592 Hz to 7.591 Hz. When the next frequency of the three - leaf fork starts to change to 7.591 Hz, it is used as the monitoring ending point. In this time period, N is 0.06647 Hz. And during this time period, the number of frames of the photos obtained by taking frames of the camera for the process of the tow moving from marking point Ⅰ to end point Ⅰ and then back to marking point Ⅰ is counted to get N1 as 72 frames. At the same time, the number of frames of the photos obtained by taking frames of the camera for the process of the tow moving from marking point Ⅱ to end point Ⅱ and then back to marking point Ⅱ is counted to get N2 as 73 frames. Finally, through calculation, it is known that the deviation between N1 and N2 is 1.39%, indicating that the movement of the three - leaf fork is normal.

[0056] Example 4

[0057] The above - mentioned method for on - line detecting whether the movement of the three - leaf fork is abnormal is used for on - line monitoring. Among them: the winding speed is 4900 m / min, the number of cakes on the winding head is 8 in total, the number of cameras and stroboscopic light sources is 8 groups, the thickness of the wound cake is 95 mm, and the diameter is 372 mm;

[0058] The interval time for one change in the rotation frequency of the three - leaf fork is 18 s. Marking point Ⅰ and marking point Ⅱ are set 24 mm inside the corresponding friction rollers at both ends of the travel of the tow. The frequency change range of the three - leaf fork is 7.5 - 7.7 Hz;

[0059] During the process where the rotation of the three - leaf fork drives the tow to move back and forth on the cake - forming surface, when the frequency of the three - leaf fork starts to change to 7.696 Hz, it is used as the monitoring starting point. The next frequency of the three - leaf fork will change from 7.696 Hz to 7.695 Hz. When the next frequency of the three - leaf fork starts to change to 7.695 Hz, it is used as the monitoring ending point. In this time period, N is 0.05542 Hz. And during this time period, the number of frames of the photos obtained by taking frames of the camera for the process of the tow moving from marking point Ⅰ to end point Ⅰ and then back to marking point Ⅰ is counted to get N1 as 102 frames. At the same time, the number of frames of the photos obtained by taking frames of the camera for the process of the tow moving from marking point Ⅱ to end point Ⅱ and then back to marking point Ⅱ is counted to get N2 as 108 frames. Finally, through calculation, it is known that the deviation between N1 and N2 is 5.88%, indicating that the movement of the three - leaf fork is abnormal.

[0060] Example 5

[0061] Online monitoring is carried out by using the above method for online detecting whether the movement of the three - lobe fork is abnormal. Among them: the winding speed is 5200 m / min, the number of bobbins on the winding head is 12 in total, the number of cameras and stroboscopic light sources is 12 groups, the thickness of the wound bobbin is 95 mm, and the diameter is 370 mm;

[0062] The interval time for the rotation frequency of the three - lobe fork to change once is 20 s. Marking point Ⅰ and marking point Ⅱ are set 24 mm inside the corresponding friction rollers at both ends of the travel of the fiber bundle. The frequency change range of the three - lobe fork is 7.6 - 7.8 Hz;

[0063] During the process that the three - lobe fork rotates to drive the fiber bundle to move back and forth on the bobbin forming surface, when the frequency of the three - lobe fork starts to change to 7.8 Hz, it is used as the monitoring starting point. The next time the frequency of the three - lobe fork will change from 7.8 Hz to 7.799 Hz. When the next frequency of the three - lobe fork starts to change to 7.799 Hz, it is used as the monitoring end point. During this time period, N is 0.04989 Hz. At the same time, during this time period, the number of frames of the photos obtained by the camera when the fiber bundle moves from marking point Ⅰ to end point Ⅰ and then returns to marking point Ⅰ is counted to get N1 as 116 frames, and the number of frames of the photos obtained by the camera when the fiber bundle moves from marking point Ⅱ to end point Ⅱ and then returns to marking point Ⅱ is counted to get N2 as 120 frames. Finally, through calculation, it is known that the deviation between N1 and N2 is 3.45%, which indicates that the movement of the three - lobe fork is normal.

Claims

1. A method for online detecting whether the movement of a three-lobe fork is abnormal. A three-lobe fork is installed on the traverse box of a winding head. A friction roller is installed below the three-lobe fork. A spindle is provided below the friction roller. A paper tube is installed on the spindle. A tow is wound on the paper tube to form a cake. During the winding process, the cake contacts the friction roller and the rotation directions of the cake and the friction roller are opposite. It is characterized in that: A camera and a stroboscopic light source are installed on the wire separating plate of the winding head. Both the camera and the stroboscopic light source face the bobbin. Denote the installation positions of the camera and the stroboscopic light source as point A and point A' respectively. The midpoint of any two endpoints along the length direction on the forming surface of the bobbin is point B. Point A is at the same height as the central axis of the friction roller. Point A' is directly above point A. The connection line between point A and point B is parallel to the end face of the bobbin. The three-leaf fork rotates to drive the wire bundle to move back and forth on the forming surface of the bobbin. The rotation frequency of the three-leaf fork changes every 10 - 20 s. Control the stroboscopic frequency of the stroboscopic light source to be equal to the frame-taking frequency of the camera. Marking points are set on the inner sides of the friction rollers corresponding to the two ends of the wire bundle's travel, denoted as marking point Ⅰ and marking point Ⅱ respectively. Denote the two ends of the wire bundle's travel near marking point Ⅰ and marking point Ⅱ as endpoint Ⅰ and endpoint Ⅱ respectively. During the selected time period, count the number of frames of the photos obtained by the camera when the wire bundle moves from marking point Ⅰ to endpoint Ⅰ and then returns to marking point Ⅰ to get N1. At the same time, count the number of frames of the photos obtained by the camera when the wire bundle moves from marking point Ⅱ to endpoint Ⅱ and then returns to marking point Ⅱ to get N2. If the deviation between N1 and N2 is greater than 5%, it indicates that the movement of the three-leaf fork is abnormal, otherwise it indicates that the movement of the three-leaf fork is normal; The selected time period refers to the time from the start of one change in the rotation frequency of the three-leaf fork to before the next change; The stroboscopic frequency of the stroboscopic light source = the rotation frequency of the three-leaf fork × 3 - N. The frequency of the three-leaf fork is 7.3 - 7.8 Hz, N = 0.04989 - 0.09954 Hz.

2. The method for on-line detecting whether the movement of a three-leaf fork is abnormal according to claim 1, wherein An online detection of whether the movement of the three-leaf fork is abnormal is realized by installing a fork synchronous video detection system on the winding head. The fork synchronous video detection system includes a stroboscopic light source, a camera, a stroboscopic light source frequency modulation control module, a variable frame imaging control module, a fork frequency converter, a parameter control main board, a display, and an imaging analysis host. Each bobbin corresponds to a set of camera and stroboscopic light source. The stroboscopic light source is connected to the stroboscopic light source frequency modulation control module. The camera is connected to the variable frame imaging control module. The fork frequency converter is connected to the fork motor. The fork motor drives the three-leaf fork to rotate through a transmission device. The parameter control main board is connected to the fork frequency converter, the stroboscopic light source frequency modulation control module, and the variable frame imaging control module simultaneously through the 485 communication protocol. The camera, the imaging analysis host, and the display are connected in sequence.

3. The method for online detecting whether the movement of a three-leaf fork is abnormal according to claim 2, characterized in that, The number of bobbins on the winding head is 8 - 16. The 8 - 16 bobbins correspond to 8 - 16 sets of camera and stroboscopic light source respectively. The 8 - 16 cameras are connected to the variable frame imaging control module simultaneously. The 8 - 16 stroboscopic light sources are connected to the stroboscopic light source frequency modulation control module simultaneously.

4. A method for online detecting whether the movement of a three-leaf shift fork is abnormal according to claim 3, characterized in that, The thickness of the bobbin is 75 - 95 mm, and the diameter of the bobbin is 370 - 375 mm.

5. The method for online detecting whether the movement of a three-leaf shift fork is abnormal according to claim 4, characterized in that, The winding speed is 4000 - 5200 m / min.

6. The method for online detecting whether the movement of a three-leaf fork is abnormal according to claim 1, characterized in that, Marking point Ⅰ and marking point Ⅱ are set 10 - 24 mm inside the friction rollers corresponding to the two ends of the wire bundle's travel.

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