Method for monitoring at least one roller of a drafting unit of a textile machine, textile machine, and use of a monitoring unit

Abstract

The invention relates to a method for monitoring at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) of a drafting unit (2) of a textile machine (1), in particular at least one top roller (4a, 5a, 6a) of the drafting unit (2). According to the invention, an actual state of a roller surface (8) of the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) is detected by means of at least one non-contact detection device (9), and the actual state is compared with a desired state of the roller surface (8), wherein the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) is illuminated by at least one light source (13). The invention also relates to a textile machine (1) and to a use of a monitoring unit (15).

Description

[0001] Method for monitoring at least one roller of a drafting system of a textile machine, textile machine and use of a monitoring unit

[0002] The present invention relates to a method for monitoring at least one roller of a drafting system of a textile machine, in particular at least one top roller of the drafting system. Furthermore, the invention relates to a textile machine and the use of a monitoring unit.

[0003] It is known in the art to monitor a roller of a drafting system of a textile machine, especially a draw frame, so that unwanted winding of a fiber strand, which can also be called laps or winders, can be detected. This is often done using sensing rollers that rest against the roller. However, systems are also known that monitor lap formation on rollers using sensors.

[0004] For example, WO 96 / 15969 A1 discloses a method and device for detecting a thread winder on a rotating roller of a rinsing device, partially wrapped around the thread. A light sensor detects reflected light from a monitoring area. The disadvantage of this is that only thread winders already present on the roller are detected. In order to minimize malfunctions and / or damage to the textile machine or the fiber structure or the thread, an immediate response, such as a thread cut, may be necessary after the formation of a thread winder, leading to production downtime. In addition, detection and evaluation based on scattered light may be inaccurate, or false detection may occur.

[0005] Furthermore, DE 10 2021 120 188 A1 discloses a drafting system for a spinning preparation machine, comprising a plurality of drafting rollers. An optical monitoring device is assigned to the drafting system. The disadvantage of this is that laps cannot be detected or estimated before they form.

[0006] The object of the present invention is to eliminate the disadvantages known from the prior art. In particular, the object is to create a method, a textile machine, and / or a monitoring unit that allows for the early detection of a fiber strand or a lap and / or the prevention of lap formation.

[0007] The object is achieved by a method for monitoring at least one roller of a drafting system of a textile machine, a textile machine and a use of a monitoring unit having the features of the independent patent claims.

[0008] A method is proposed for monitoring at least one roller of a drafting system of a textile machine, in particular at least one top roller of the drafting system. The textile machine is preferably a fiber sliver-forming textile machine, in particular a draw frame.

[0009] With the help of the drafting system, at least one fiber sliver is drawn in the textile machine. This fiber sliver can then be further processed. In a textile machine designed as a draw frame, several individual fiber slivers are combined and drawn to initially form a fiber web. The fiber web emerging from the drafting system has a increased homogeneity. The fiber sliver leaves the drafting system as a fiber web or as a spread-out fiber sliver, i.e. it has a small thickness compared to its width. After leaving the drafting system, the fiber web is fed to a web nozzle, which forms the fiber web back into a fiber sliver. Both the fiber web and the fiber sliver can be called a fiber structure. The drafting system preferably comprises three or more pairs of rollers or roller arrangements, each of which can comprise at least one bottom roller and one top roller. The bottom rollers are often also referred to as cylinders.The desired draft of the fiber strand is achieved by the fact that the individual cylindrical lower rollers, and thus also the individual upper rollers in contact with them, have an increasingly higher peripheral speed in the transport direction of the fiber strand. This pulls the fiber strand apart in the transport direction and thus stretches it. The drafting system usually has an input roller pair, a middle roller pair, and / or an output roller pair. Preferably, in the proposed method, at least one of the upper rollers of the input roller pair, the middle roller pair, and / or the output roller pair is monitored.

[0010] According to the invention, an actual state of a roller surface of the at least one roller is detected by means of at least one contactless detection device. Furthermore, the actual state is compared with a desired state of the roller surface. Furthermore, the at least one roller is illuminated by at least one light source.

[0011] The target state is defined here by the fact that the at least one roller of the drafting system operates essentially flawlessly and / or a fiber structure of high quality is produced. Additionally or alternatively, the target state is defined by the fact that there is the lowest possible probability of laps or windings of the fiber structure on the at least one monitored roller. This probability is low if the roller surface of the at least one monitored roller is as optimal as possible or almost optimal. This optimal condition of the roller surface is often achieved after the grinding process of the roller or the roller cover or after the installation of a new roller. The optimal condition or the target state lasts for a running time after grinding or after the replacement of the at least one roller, which is why recording or monitoring the roller surface is advantageous.It can also happen that the optimal condition or the target condition is not achieved after grinding because the roller diameter is not met.

[0012] By comparing the target and actual condition of the roller surface, it is possible to determine when and / or how at least one roller deviates from the target condition. This makes it possible to predict the formation of a lap or unwanted winding of fiber strands before they occur. Machine productivity can be increased by reducing the winding tendency and / or increasing the maximum delivery speed. Additionally or alternatively, monitoring the roller surface can improve the quality of the fiber strand and / or the yarn produced from it.

[0013] Illumination with the light source can improve the detection accuracy of the contactless detection device. This allows the actual condition of the roll surface and / or a subsequently more precisely defined deviation to be more accurately detected. The actual condition of the roll surface or the deviation is very difficult to detect or record compared to a roll that has at least partially rolled onto at least one roll. Only with the help of illumination is it possible to detect and / or record this actual condition of the roll surface or the deviation.

[0014] The light source is preferably designed as an LED. The light source can be configured to accommodate different spectra by having multiple radiation sources and / or switching between them using appropriate filters. Wavelengths from the entire spectrum, from ultraviolet to infrared, are advantageously used. Furthermore, the light source should have an illuminance of at least 800 LUX, preferably more than 1200 LUX. For example, one or more electronic flash units are used as the light source. An illuminance of more than 10,000 LUX can be achieved. Additionally or alternatively, the light source can emit a constant and / or periodic light.

[0015] It is advantageous if the actual state is recorded using at least one camera and / or at least one sensor as a detection device. This allows the contactless detection to be recorded with the greatest possible detail using the detection device. The detection device designed as a camera is also inexpensive to manufacture and can easily record the actual state optically.

[0016] The camera can be a still camera, video camera, high-speed camera, and / or thermal imaging camera. Still cameras, video cameras, and / or high-speed cameras primarily capture images in the light wave range, which is also visible to the human eye. In contrast, thermal imaging cameras primarily operate in the invisible infrared range. The sensor can be a light sensor, lidar, and / or radar, for example. Radar uses radio waves, while lidar uses laser beams to measure distance, speed, and / or acceleration. An additional advantage of lidar or radar can be the lower sensitivity of the image to flying lint in textile machines.

[0017] Furthermore, it is advantageous if the detection device detects the actual condition of the roller surface of a roller cover of the at least one roller. In particular, the top rollers of the drafting system often have roller covers. Due to their material, these roller covers have a higher probability of deviations compared to the bottom rollers, which is why the winding tendency can be increased here. It is also advantageous if the detection device detects the actual condition of the roller surface of a top roller following a main draft, in particular an output top roller, of the drafting system. The top roller following the main draft is of great importance with regard to the quality of the fiber structure to be produced. This roller is often the output top roller. In this case, it may therefore be sufficient to monitor only this output top roller.Monitoring of the other drafting rollers can thus be omitted, particularly for economic reasons.

[0018] It is also advantageous if, based on the comparison between the actual and target conditions, a deviation in the roll surface, particularly one that promotes winding, is detected. The deviation is categorized depending on its type and / or origin, for example, as a structural deviation and / or dimensional deviation. Classifying the deviations into different categories facilitates subsequent evaluation of the deviations. It also enables a simple evaluation of the predominant deviations in the roll surface.

[0019] Structural deviations include, for example, damage to the roller surface and / or firmly adhering particle deposits on the roller surface. Dimensional deviations include, for example, changes in the roller diameter of the at least one roller. Damage to the roller surface can occur, for example, when laps or spools are removed using a knife. Damage can also occur during operation of the drafting system. Particle deposits can, for example, be color particles that are transported along with the fiber structure and that adhere firmly to the at least one roller during drafting. Such solid deposits can also be, for example, individual fibers and / or cotton residues that are individually and firmly adhered to the roller.Changes in the roller diameter, however, usually occur with increasing running time, since the surface of at least one roller is worn away due to loads and / or the grinding process.

[0020] It is also advantageous if, when monitoring multiple rollers of a textile machine, the detected deviation is assigned to one of the rollers, in particular to one of the top rollers of the drafting system. This makes it possible, if multiple rollers of the drafting system are monitored, to locate the roller with the predominant deviation and / or determine the type of deviation. This allows at least one roller with the predominant deviation to be replaced and / or ground, restoring the desired condition.

[0021] The structural deviation advantageously exists when the actual state of surface roughness falls below or exceeds the target state, which for rollers in the drafting system is preferably in an RA value range between 0.4 and 1.1, in particular between 0.5 and 1.0. Surface roughness is understood to mean an unevenness of the roller surface. The RA value is referred to as the mean roughness. With increasing running time of the rollers (for example after more than 500 hours), the surface roughness can decrease. As a result, the actual state of the RA value can fall below the target state of 0.5, in particular 0.8, so that the structural deviation occurs due to the RA value falling below the range. Alternatively, the surface roughness can be increased, for example due to particle deposits and / or damage to the roller surface.Due to such particle deposits and / or damage, the actual state can exceed the target state of the RA value of 1.1, in particular 1.0, so that the structural deviation occurs due to the RA value range being exceeded. Both falling below and exceeding the RA value range can lead to an increased tendency to wind and / or reduced quality of the fiber structure. Additionally or alternatively, the structural deviation occurs when the actual state of a depression or elevation on the roller surface exceeds the target state, which in the case of rollers in the drafting system is preferably at most 0.3 mm deep or high, in particular 0.5 mm. The depression can, for example, be formed as a notch due to mechanical action, in particular by a knife when removing a lap. Elevations are usually caused by adhering particle deposits.

[0022] Additionally or alternatively, a structural deviation exists when the actual state of a surface coloration exceeds the target state, which for rollers of the drafting system is preferably 40%, in particular 50%. As already described above, color particles can deposit on the roller surface, which are recognizable as a structural deviation by means of the surface coloration. This allows deposits to be detected very easily, for example, using an optical detection device. Surface coloration is understood here as the percentage of colored roller surface in relation to the total roller surface of the at least one roller.

[0023] It is also advantageous if the dimensional deviation occurs when the actual state of a roller diameter falls below the target state, which for rollers of the drafting system is preferably at least 36 mm. As the running time of the at least one monitored roller increases, the roller diameter decreases. This reduction in the roller diameter can, as already described, occur through proper use during operation of the drafting system and / or through grinding of the at least one roller.

[0024] If at least one of the actual states described above exceeds or falls below the respective specified target state, essentially error-free operation of the drafting system is no longer guaranteed. This can be easily determined and / or responded to by determining and / or categorizing the deviation. Thus, measures, such as replacing or grinding at least one roller, can preferably be initiated so that the roller surface returns to the target state.

[0025] It is also advantageous if a deviation is indicated and / or the drafting system is stopped when it occurs. This allows the deviation to be remedied with appropriate measures. For example, in the case of a structural deviation, at least one roller can be ground and / or cleaned. In the case of a dimensional deviation, at least one roller and / or the roller cover can be replaced and / or renewed.

[0026] It is advantageous if, following a machine stoppage, in particular triggered by a sliver sensor, the roller surface of the at least one roller is checked and / or a deviation is indicated. The sliver sensor can be designed, for example, as a mechanical sliver sensor, which is arranged in particular on at least one calender roller of the textile machine, and / or as a microwave cavity resonator. The sliver sensor can determine the quality of the fiber structure. Additionally or alternatively, the sliver sensor can determine the sliver f value and / or initiate a machine stop if the sliver CV values ​​are too high. In this way, the at least one roller can be checked to determine whether and / or how this has an effect on the sliver quality and / or the machine stoppage. During the test, the at least one roller is preferably rotated further, at least partially and / or for a limited time.This allows the deviation of the roll surface, especially the structural deviation, to be checked along the entire circumference.

[0027] It is also advantageous if the detection device and / or the light source are cleaned, particularly with the aid of a cleaning device. This ensures that the actual state and / or any deviations are always detected. The cleaning device can be a mechanical cleaning device (windshield wiper) and / or a blower device. In textile machines that process fiber composites, free fiber material usually forms in the area of ​​the stretching machine, which can be extracted using a suction unit. Other dirt particles, such as color particles, can also adhere to the detection device and / or the light source. In order to remove this fiber material or the other dirt particles, an appropriate cleaning device is helpful. This allows cleaning to be automated.

[0028] Furthermore, it is advantageous if the detection device and / or the light source is moved into a detection position, particularly with the aid of an adjusting device, and / or pivoted in the detection position. This allows, for example, the detection device and / or the light source to be arranged in a rest position during operation of the drafting system and only moved into the detection position, in which the actual condition of the roller surface can be detected, when needed. For example, the detection device and / or the light source can be arranged outside the dirt area or outside the area where increased fiber fly prevails during operation of the drafting system. This reduces the risk of contamination.For example, the adjusting device can be a pneumatic cylinder already required for the suction unit, which indirectly adjusts the detection device and / or light source attached to the suction unit from the rest position to the detection position.

[0029] Additionally or alternatively, the adjusting device can adjust the detection device and / or the light source from a lateral rest position adjacent to the drafting system toward a detection position arranged essentially centrally to the normal plane extending to the at least one roller. It is also conceivable for the detection device and / or the light source to be pivoted in the detection position with the aid of the adjusting device. Thus, several rollers and / or the at least one roller can be detected along their width with the aid of one detection device and / or illuminated by one light source.

[0030] It is also advantageous if the actual status is recorded when the roller is rotating and / or stationary, in particular during or shortly after a machine stoppage and / or can change. During a machine stoppage and / or can change, for example, the monitored roller can be rotated at a slower speed, making it easier to detect the actual status or any deviations. While the roller is rotating, i.e. during normal operation of the textile machine, continuous recording is possible. For example, it is also possible to carry out simplified monitoring during operation of the textile machine and detailed monitoring of at least one roller when the machine is stopped or when the can is changed.

[0031] Furthermore, a textile machine, in particular a draw frame and / or air-jet spinning machine and / or ring spinning machine, with a drafting system having at least one roller is proposed.

[0032] According to the invention, the textile machine comprises a monitoring unit with at least one contactless detection device for monitoring the at least one roller, in particular at least one top roller, of the drafting system. Furthermore, the monitoring unit comprises at least one light source for illuminating the at least one roller, in particular at least one top roller, of the drafting system. The interaction of the detection device and the light source can improve the detection of an actual condition of the roller surface of at least one of the rollers.

[0033] It is advantageous if the monitoring unit has a fastening section that is arranged in the region of a bearing device of the at least one roller and / or a suction unit of the textile machine. The bearing device mounts the at least one roller on the drafting system. In the case of at least one of the upper rollers, in particular the output upper roller, the bearing device of the at least one roller is to be understood as a load arm of the drafting system. If the monitoring unit is arranged in the region of the bearing device of the at least one lower roller, it can be arranged or fastened, for example, in the region of or within a pressure bar. If the monitoring unit is arranged on the suction unit, this is preferably done on the suction hood, which is arranged above the upper rollers. This can also be designed to be movable, thereby simplifying the maintenance of the monitoring unit and / or simplifying detection.

[0034] It is also advantageous if the monitoring unit is assigned a control device which is designed to control the monitoring unit and / or the textile machine according to a method according to the preceding description, wherein the features mentioned can be present individually or in any combination.

[0035] It is also advantageous if the at least one detection device is designed as a sensor and / or camera, wherein the at least one detection device preferably has a resolution for detecting a deviation with an extent of 0.1 mm 2 on the roller surface. Resolution allows even the finest deviations on the roller surface to be detected. A deviation with an extent of 0.1 mm 2corresponds to the size of a grain of dust. This resolution is necessary to detect and categorize even the smallest deviations. If the detection device is preferably designed as a camera, it can be a simple CCD camera or RGB camera, for example.

[0036] It is advantageous if the respective frequency ranges of the light source and the camera are matched to each other, allowing optical detection of the roller surface over time under consistent conditions. Furthermore, it is advantageous if the light source and the detection device are aligned such that a light axis and a detection axis impinge on the roller surface in a monitoring area.

[0037] The detection device has a detection angle. The light source has a radiation angle. The monitoring area is preferably arranged or positioned both within the detection angle and within the radiation angle. This ensures that the monitoring area in which the roller surface to be monitored is located is sufficiently illuminated and can be detected by the detection device.

[0038] It is also advantageous if the monitoring unit is arranged at least partially centrally to the at least one roller. Preferably, the at least one detection device and / or the at least one light source are arranged substantially centrally.

[0039] It is also advantageous if a detection axis of the at least one detection device forms a first angle with a normal plane of the at least one roller that runs normal to a rotational axis of the at least one roller. Additionally or alternatively, a light axis of the at least one light source forms a second angle with the normal plane of the at least one roller. Preferably, the first angle and / or the second angle is less than or equal to 30°, in particular less than or equal to 15°. The larger the first angle and / or the second angle, the less accurately deviations can be detected and / or illuminated, since distortion occurs due to the angle. In addition, by keeping the angle as small as possible, the detection axis and / or the light axis can be as short as possible, so that the resolution of the detection device and / or the illuminance of the light source are utilized as fully as possible.

[0040] It is also advantageous if the detection axis and / or the light axis impinge on the roller surface within a range of 5 mm from the normal plane, wherein the normal plane preferably runs essentially centrally to the at least one roller. The fiber structure usually runs essentially centrally along the roller surface of the at least one roller. This allows the detection of precisely the area of ​​the at least one roller where the fiber structure touches the roller surface.

[0041] It is advantageous if the monitoring unit is assigned a cleaning device which is designed to clean the at least one detection device and / or the at least one light source.

[0042] It is also advantageous if the textile machine comprises a display device and / or a fiber sliver sensor, wherein the control device, the display device, the fiber sliver sensor, and / or the monitoring unit are operatively connected to one another. For example, a method can be carried out with at least one method step of the preceding description.

[0043] Furthermore, the use of a monitoring unit for monitoring at least one roller of a textile machine is proposed. According to the invention, the monitoring unit has at least one contactless detection device and at least one light source. The monitoring unit is designed to detect and / or monitor an actual state of a roller surface of the at least one roller of the textile machine. The at least one light source illuminates the roller surface, and the at least one contactless detection device detects the actual state of the illuminated roller surface of the at least one roller. The textile machine is preferably designed according to the preceding description, wherein the aforementioned features can be present individually or in any combination.Additionally or alternatively, the monitoring unit and / or the contactless detection device is designed to detect and / or monitor the actual state according to the preceding description, wherein the features mentioned can be present individually or in any combination.

[0044] It is advantageous if the monitoring unit comprises at least one feature of the preceding description, wherein the said features can be present individually or in any combination.

[0045] Further advantages of the invention are described in the following exemplary embodiments. It shows:

[0046] Figure 1 is a schematic side view of a textile machine and

[0047] Figure 2 is a schematic plan view of a drafting system according to an alternative embodiment.

[0048] Figure 1 shows a schematic side view of a textile machine 1 according to one exemplary embodiment. In the illustrated exemplary embodiment, the textile machine 1 is designed as a draw frame. For a clearer illustration, only a section of the draw frame is shown. The section shown here is the area of ​​a draw frame 2 of the textile machine 1.

[0049] The textile machine 1 comprises the drafting system 2 with at least one roller 4-7 that draws a fiber strand 3. In the illustrated embodiment, the drafting system 2 has an input roller pair 4a, 4b with an input lower roller 4b and an input upper roller 4a, a middle roller pair 5a, 5b with a middle lower roller 5b and a middle upper roller 5a, and an output roller pair 6a, 6b with an output lower roller 6b and an output upper roller 6a. The drafting system 2 also has a deflection roller 7. The input upper roller 4a, the middle upper roller 5a, the output upper roller 6a, and the deflection roller 7 are arranged or mounted as upper rollers 4a, 5a, 6a, 7 on a bearing device 17 designed as a loading arm. The input lower roller 4b, the middle lower roller 5b and the output lower roller 6b are arranged or mounted on a further bearing device not shown in the embodiment shown.

[0050] Between the input roller pair 4a, 4b and the middle roller pair 5a, 5b, the fiber strand 3 is drawn by a pre-drafting zone or a pre-drafting zone. Between the middle roller pair 5a, 5b and the output roller pair 6a, 6b, the fiber strand 3 is drawn by a main drafting zone or a main drafting zone. The main draft is usually greater than the pre-drafting zone. The respective draft is formed due to the different rotational speeds of the roller pairs around a respective rotational axis 21, or rather, the speeds increasing from the input to the output roller pair 6a, 6b. In the exemplary embodiment shown, the system 2 is a so-called four-over-three drafting system 2, since the drafting system 2 comprises four upper rollers 4a, 5a, 6a, 7 and three lower rollers 4b, 5b, 6b. However, the method according to the invention and / or the textile machine 1 according to the invention can also be carried out with other drafting systems 2.

[0051] During the intended use of the drafting system 2, each of the rollers 4-7 rotates about the rotation axis 21. Furthermore, at least one of the rollers 4-7, preferably the top rollers 4a, 5a, 6a and / or the deflection roller 7 of the drafting system 2, comprises a roller cover 10. The roller core is preferably made of steel or aluminum. The roller cover 10 is preferably made of a polymer or a synthetic rubber. During the intended use of the drafting system 2, the roller cover 10 is therefore primarily subject to wear and / or damage and / or dirt. Furthermore, a pressure bar 29 is arranged in the main drafting zone, which deflects the fiber strand 3 and thus ensures better guidance of the fibers. A deflection roller 7 deflects the fiber strand 3 in the direction of a calender roller pair 27.For example, a nonwoven guiding device (not shown), in particular with a sliver funnel and / or a nonwoven funnel, can be arranged upstream of the calender roller pair 7. In the illustrated embodiment, a fiber sliver sensor 12 is arranged downstream of the calender roller pair 7, which monitors the fiber strand 3. With the help of the fiber sliver sensor 12, the quality of the fiber strand 3 being fed through can be determined. For example, a CV value or sliver CV value can be measured with the help of the fiber sliver sensor 12. The fiber strand 3 is then deposited in a can (not shown).

[0052] Since dirt, in particular fibers and / or dust and / or color particles, are released from the fiber structure 3 during the drafting process, a suction unit 18 (not absolutely necessary or optional) is provided for the textile machine 1 in the illustrated embodiment. The suction unit 18 usually comprises a suction hood mounted or pivotable on a pivot axis 31. In the illustrated embodiment, several air guiding elements 30 are arranged within the suction hood, which, for example, provide the suction air for the dirt or fiber fly. Additionally or alternatively, the air guiding elements 30 can be designed as stripping elements and / or have the stripping element at their ends directed towards the rollers 4 - 7, so that fiber deposits on the rollers 4 - 7 can be removed or collected when in contact with the roller 4 - 7.For this purpose, the air guide elements 30 can be moved toward and / or away from the rollers 4-7, in particular by means of an adjusting device 28. Furthermore, the suction unit 18 can be lifted or pivoted upward about the pivot axis 31 by means of the adjusting device 28. This, for example, can ensure simplified access to the drafting system 2 for an operator and / or facilitate the insertion of the fiber strand 3.

[0053] According to the invention, the textile machine 1 comprises at least one monitoring unit 15 with at least one contactless detection device 9 for monitoring the at least one roller 4-7, in particular at least one top roller 4a, 5a, 6a, 7, of the drafting system 2. In the exemplary embodiment shown, the contactless detection device 9 is arranged or fastened by means of a fastening section 16 in the region of the suction unit 18, in particular on the air guiding elements 30 of the suction unit 18. The contactless detection device 9 and the fastening section 16 are components of the monitoring unit 15 in the exemplary embodiment shown. The monitoring unit 15 also comprises a light source 13. With the aid of the light source 13, the at least one roller 4-7 can be illuminated, so that the detection of a roller surface 8 of the at least one roller 4-7 is facilitated or qualitatively improved with the aid of the detection device 9.Due to the illumination provided by the light source 13, the detection of the detection device 9, which is designed as an optical sensor and / or camera, can be improved, or the detection of the deviation 11 can only be made possible by the light source 13. It is also conceivable for the detection device 9 to be designed as a "non-optical" sensor. The detection device 9 preferably always has a resolution sufficient to detect deviations 11 with an extent of 0.1 mm. 2 on the roller surface 8.

[0054] The textile machine 1 shown is designed to carry out the method according to the invention for monitoring at least one of the rollers 4-7 of the drafting system 2. For this purpose, the monitoring unit 15 or the detection device 9 can detect an actual state of the roller surface 8 of at least one of the rollers 4-7 in a contactless manner. In the exemplary embodiment shown, the actual state of the output top roller 6a is detected, for example. This actual state is subsequently compared with a desired state of the roller surface 8. Based on the comparison between the actual state and the desired state, a deviation 11 of the roller surface 8 is detected. The deviation 11 is preferably categorized, for example, into a structural deviation and / or dimensional deviation depending on its type and / or origin.

[0055] In the exemplary embodiment shown, the structural deviation, in particular a local elevation of the roller surface 8, is shown as deviation 11. The structural deviation can arise due to particle deposits. With such elevations of the roller surface 8, the structural deviation exists when the height of the deposit exceeds 0.3 mm, in particular 0.5 mm. The detection device 9 detects the actual state of the depression or elevation of the roller surface 8 and compares this with the target state. Additionally or alternatively, the structural deviation can exist when the actual state of a surface roughness falls below or exceeds the target state, which for rollers 4 - 7 of the drafting system 2 is preferably in an RA value range between 0.4 and 1.1, in particular between 0.5 and 1.0.The structural deviation may also occur if the actual state of a surface coloration exceeds the target state, which for rollers 4 - 7 of the drafting system 2 is preferably 40%, in particular 50%.

[0056] The detection device 9 is also preferably designed such that it can detect dimensional deviations. A dimensional deviation exists when the actual state of a roller diameter falls below the target state, which for rollers 4-7 of the drafting system 2 is preferably at least 36 mm. For example, the detection device 9 can determine the roller diameter by determining the distance to the roller surface 8. If the detection device 9 is designed as a camera, it is advantageous to simultaneously detect the surface coloration so that structural deviations are not erroneously categorized as dimensional deviations. It is also conceivable for the roller diameter to be measured using the detection device 9 designed as a sensor, in particular the lidar or radar sensor.Additionally or alternatively, deviations 11, in particular the different categories of deviations 11, can be recorded using several identical or different recording devices 9.

[0057] If a deviation 11 is detected, it can be displayed, for example, by means of a display device 26. Additionally or alternatively, the drafting system 2 can be stopped after the deviation 11 occurs. It is also conceivable that, after a machine stop triggered by other means, in particular the sliver sensor 12, the actual condition of the roller surface 8 is checked and / or the deviation 11 is displayed. The sliver sensor 12 can, for example, initiate the machine stop if the CV value of the fiber strand 3 is too high. A high CV value indicates insufficient drafting, which can arise from deposits or deviations 11 on the roller surface 8.

[0058] After the machine has stopped, it is conceivable that at least one roller 4 - 7 is rotated further so that the roller surface 8 can be inspected more precisely and / or continuously. In this case, it can be checked whether the increased CV value is due to deviations 11 of the roller surface 8. Additionally or alternatively, after the machine has stopped, the adjusting device 28 can pivot the suction unit 18 for simplified detection. This makes it possible, for example, to detect a plurality of the rollers 4 - 7 with the aid of the detection device 9. It is also conceivable that the detection device 9 is arranged below the suction unit 18, in particular in the region of the adjusting device 28, so that it is arranged outside the fiber fly or dirt area during the intended use of the drafting system 2.The detection device 9 is adjusted between a rest position and a detection position with the aid of the positioning device 28 indirectly via the suction unit 18.

[0059] If the deviation 11 has been detected on the roller surface 8, it can be displayed, particularly together with the deviation category. An operator can then remove the deposits (by cleaning and / or grinding) and / or replace the roller 4-7. Preferably, the detection device 9, the fiber sliver sensor 12, and / or the display device 26 are operatively connected in such a way that, after the machine stops due to an excessively high CV value, the operator is notified to clean, grind, and / or replace the roller 4-7. If several of the rollers 4-7 are detected, it is also conceivable for the operator to be shown the roller 4-7 to be cleaned, ground, and / or replaced.

[0060] For example, the textile machine 1, as shown in the exemplary embodiment shown, can have a control device 19 which is operatively connected to the monitoring unit 15, the fiber sliver sensor 12 and / or the display device 26 in order to control the textile machine 1 according to the method. For example, depending on the type and / or origin of the deviation 11, different instructions can appear on the display device 26 and / or the machine can be stopped. For example, if a dimensional deviation is detected, the roller 4 - 7 usually needs to be replaced. If a structural deviation is detected, cleaning and / or grinding can often already improve the quality of the fiber structure 3. The display device 26 can also be used to alert the operator at an early stage to an impending intervention.

[0061] To ensure that the actual state is always detected, the monitoring unit 15 in the illustrated embodiment has a cleaning device 14 that is designed to clean the at least one detection device 9 and / or the at least one light source 13. Additionally or alternatively, to avoid contamination, the monitoring unit 15 and / or the detection device 9 can be adjusted between the detection position and the rest position using the adjusting device 28. For this purpose, the rest position should be arranged outside the dirt area. It is thus conceivable that the monitoring unit 15 and / or the detection device 9 is adjusted or moved in the normal sheet direction. For this purpose, a further adjusting device 28 or an alternative adjusting device 28 is necessary. Reference is made to Figure 2, which shows a corresponding adjusting device 28 very schematically.

[0062] In the following description of the alternative embodiment shown in Figure 2, the same reference numerals are used for features that are identical and / or at least comparable in their design and / or mode of operation compared to the first embodiment shown in Figure 1. Unless explained in detail again, their design and / or mode of operation corresponds to the design and mode of operation of the features already described above. Features that are only present in one of the embodiments of Figures 1 or 2, for example the roll cover 10, the fiber sliver sensor 12, the cleaning device 14, the suction unit 18, the control device 19, the display device 26, the calender roll pair 27, can also be transferred to the other embodiment.

[0063] Figure 2 shows a (highly) simplified, schematic plan view of a drafting system 2 according to an alternative embodiment. In contrast to the embodiment in Figure 1, only a section of the drafting system 2 with the central top roller 5a and the output top roller 6a is shown. The drafting system 2 can, for example, like that in Figure 1, be designed as a four-over-three drafting system 2. In addition, the two top rollers 5a, 6a shown are spaced far apart from one another, so that the representation of the monitoring unit 15 is simplified. In contrast to the embodiment in Figure 1, the adjusting device 28, as already briefly described above, is designed such that the monitoring unit 15 is adjustable longitudinally relative to the rollers 4-7. It is thus conceivable that the monitoring unit 15 can be brought from the detection position shown in the embodiment in Figure 2 along an adjusting direction 32 into a rest position.For example, it is possible for the rest position, as indicated here, to be located outside the bearing device 17 designed as a load arm. In the rest position, the monitoring unit 15 is protected from contamination and / or flying fibers. For this purpose, the bearing device 17 can comprise an opening, in particular a closable one, through which the monitoring unit 15 can be moved. A similar arrangement is also conceivable for the suction unit 18 according to Figure 1.

[0064] In the illustrated embodiment, the fastening section 16 is designed as a linearly movable carriage, which, for example, as shown here, moves along the compression rod 29. However, it is also conceivable that the monitoring unit 15 is arranged with the fastening section 16 in a fixed manner on the compression rod 29. It is also conceivable that the monitoring unit 15 is arranged at least partially within the compression rod 29 in a fixed or displaceable manner.

[0065] In order to be able to detect all deviations 11 on the roll surface 8 of the output top roll 6a to be monitored here, the monitoring unit 15 or the detection device 9 is arranged at least partially centrally to the at least one roll 4-7 in the illustrated embodiment. The center of the output top roll 6a is shown in the illustrated embodiment with a central normal plane 22 running normal to the rotation axis 21. The detection device 9 has a detection axis 20, from which a detection range or detection angle emanates. Thus, the detection device 9 typically detects the roll surface 8 or the deviations 11 within a detection range or detection angle formed symmetrically to the detection axis 20.In order to be able to detect the entire roller surface 8 as far as possible, it is advantageous if the detection axis 20 strikes the roller surface 8 within a range of 5 mm to the normal plane 22.

[0066] Similarly, the light source 13 has a light axis 24 from which an illumination range or illumination angle emanates. Thus, the light source 13 typically illuminates the roller surface 8 or the deviations 11 within an illumination range or illumination angle formed symmetrically from the light axis 24. In order to illuminate the entire roller surface 8 as much as possible, it is advantageous if the light axis 24 also strikes the roller surface 8 within a range of 5 mm from the normal plane 22.

[0067] The detection axis 20 of the at least one detection device 9 forms a first angle 23 with the normal plane 22. The light axis 24 of the at least one light source 13 forms a second angle 25 with the normal plane 22. To ensure the most accurate detection and / or the strongest possible illumination, the first angle 23 and / or the second angle 25, as shown in the exemplary embodiment shown, is less than or equal to 30°.

[0068] Additionally or alternatively, it is conceivable that the monitoring unit 15 can be adjusted along the adjustment direction 32 during the method according to the invention with the aid of the adjustment device 28. For example, in the case of small installation spaces in which the detection angle and / or the illumination angle is insufficient to monitor the entire roller surface 8 due to the distance to the roller surface 8, this can be ensured by means of several detection positions spaced apart from one another along the adjustment direction 32. This plurality of detection positions can each detect a section of the roller surface 8. It is also conceivable that the monitoring unit 15, the detection device 9 and / or the light source 13 are designed to be pivotable (normal to the sheet direction) so that the detection axis 20 and / or the light axis 24 can impinge on the roller surface 8 at different positions.The present invention is not limited to the illustrated and described embodiments. Modifications within the scope of the patent claims are possible, as are combinations of features, even if they are illustrated and described in different embodiments.

[0069] List of reference symbols

[0070] 1 textile machine

[0071] 2 drafting system

[0072] 3 fiber composite

[0073] 4a, 4b Input roller pair

[0074] 5a, 5b Middle roller pair

[0075] 6a, 6b Output roller pair

[0076] 7 Deflection roller

[0077] 8 roller surface

[0078] 9 Recording device

[0079] 10 roller cover

[0080] 11 Deviation

[0081] 12 Fiber ribbon sensor

[0082] 13 Light source

[0083] 14 Cleaning device

[0084] 15 Monitoring unit

[0085] 16 Fastening section

[0086] 17 Storage facility

[0087] 18 Suction unit

[0088] 19 Control device

[0089] 20 detection axis

[0090] 21 Rotation axis

[0091] 22 Normal level

[0092] 23 first angle

[0093] 24 Light axis

[0094] 25 second angle

[0095] 26 Display device

[0096] 27 pairs of calender rolls

[0097] 28 Adjusting device

[0098] 29 Pressure rod 30 Air guide element

[0099] 31 Swivel axis

[0100] 32 Setting direction

Claims

Patent claims 1 . Method for monitoring at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) of a drafting system (2) of a textile machine (1), in particular at least one top roller (4a, 5a, 6a) of the drafting system (2), characterized in that an actual state of a roller surface (8) of the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) is detected by means of at least one contactless detection device (9), and the actual state is compared with a desired state of the roller surface (8), wherein the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) is illuminated by at least one light source (13).

2. Method according to the preceding claim, characterized in that the detection device (9) detects the actual state of the roller surface (8) of a roller cover (10) of the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) and / or of a top roller (4a, 5a, 6a) following a main draft, in particular an output top roller (6a), of the drafting system (2).

3. Method according to one or more of the preceding claims, characterized in that a deviation (11) of the roller surface (8) is detected on the basis of the comparison between the actual state and the desired state, wherein the deviation (11) is preferably categorized depending on the type and / or origin, for example into a structural deviation and / or dimensional deviation.

4. Method according to one or more of the preceding claims, characterized in that that the structural deviation exists, - if the actual state of a surface roughness falls below or exceeds the target state, which for rollers (4a, 4b, 5a, 5b, 6a, 6b, 7) of the drafting system (2) is preferably in an RA value range between 0.4 and 1.1, - if the actual state of a depression or elevation of the roller surface (8) exceeds the desired state, which in the case of rollers (4a, 4b, 5a, 5b, 6a, 6b, 7) of the drafting system (2) is preferably at most at a depth or height of 0.3 mm, and / or - if the actual state of a surface coloration exceeds the target state, which is preferably 40% for rollers (4a, 4b, 5a, 5b, 6a, 6b, 7) of the drafting system (2).

5. Method according to one or more of the preceding claims, characterized in that the dimensional deviation exists when the actual state of a roller diameter falls below the desired state, which for rollers (4a, 4b, 5a, 5b, 6a, 6b, 7) of the drafting system (2) is preferably at least 36 mm.

6. Method according to one or more of the preceding claims, characterized in that when the deviation (11) occurs, this is indicated and / or the drafting system (2) is stopped.

7. Method according to one or more of the preceding claims, characterized in that following a machine stop, in particular triggered by a fiber band sensor (12), the actual state of the roller surface (8) is checked and / or the deviation (11) is displayed.

8. Method according to one or more of the preceding claims, characterized in that the detection device (9) and / or the light source (13) is cleaned, in particular with the aid of a cleaning device (14).

9. Method according to one or more of the preceding claims, characterized in that the detection device (9) and / or the light source (13), in particular with the aid of an adjusting device (28), is brought into a detection position and / or pivoted in the detection position.

10. Textile machine (1), in particular a draw frame and / or air-jet spinning machine and / or ring spinning machine, with a drafting system (2) having at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7), characterized in that the textile machine (1) has a monitoring unit (15) with at least one contactless detection device (9) for monitoring and with at least one light source (13) for illuminating the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7), in particular at least one top roller (4a, 5a, 6a), of the drafting system (2).

11. Textile machine (1) according to the preceding claim, characterized in that the monitoring unit (15) has a fastening section (16) which is arranged in the region of a bearing device (17) of the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) and / or a suction unit (18) of the textile machine (1).

12. Textile machine (1) according to one or more of the preceding claims, characterized in that the monitoring unit (15) is provided with a control device (19) which is designed to control the monitoring unit (15) and / or the textile machine (1) according to a method of one or more of the preceding claims 1 - 9.

13. Textile machine (1) according to one or more of the preceding claims, characterized in that the at least one detection device (9) is designed as a sensor and / or camera, wherein the at least one detection device (9) preferably has a resolution for detecting a deviation (11) with an extent of 0.1 mm 2 on the roller surface (8).

14. Textile machine (1) according to one or more of the preceding claims, characterized in that the monitoring unit (15) is arranged at least partially centrally to the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7).

15. Textile machine (1) according to one or more of the preceding claims, characterized in that a detection axis (20) of the at least one detection device (9) forms a first angle (23) with a normal plane (22) running normal to a rotation axis (21) of the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) and / or a light axis (24) of the at least one light source (13) forms a second angle (25) with the normal plane (22) of the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7), wherein the first angle (23) and / or the second angle (25) is preferably less than or equal to 30°.

16. Textile machine (1) according to one or more of the preceding claims, characterized in that the detection axis (20) and / or the light axis (24) are within a range of 5 mm to the normal plane (22) strikes the roller surface (8), wherein the normal plane (22) preferably runs substantially centrally to the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7).

17. Textile machine (1) according to one or more of the preceding claims, characterized in that the textile machine (1) comprises a display device (26) and / or a fiber band sensor (12), wherein the control device (19), the display device (26), the fiber band sensor (12) and / or the monitoring unit (15) are operatively connected to one another.

18. Use of a monitoring unit (15) for monitoring at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7) of a drafting system (2) of a textile machine (1), characterized in that the monitoring unit (15) has at least one contactless detection device (9) and at least one light source (13), wherein the monitoring unit (15) is designed to detect and / or monitor an actual state of a roller surface (8) of the at least one roller (4a, 4b, 5a, 5b, 6a, 6b, 7).

19. Use according to the preceding claim, characterized in that the monitoring unit (15) comprises at least one feature of the preceding claims.

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