JP4805666B2 - Fluff detection apparatus and fluff detection method - Google Patents

Description

  The present invention relates to an apparatus and a method for detecting fuzz produced by cutting a filament constituting a traveling multifilament yarn.

  In general, in a multifilament yarn composed of a large number of filament groups (single fiber group), when a filament constituted for some reason is cut, the yarn end of the cut filament appears as a fluff on the surface of the yarn. .

  The fluff generated in this manner causes various troubles in the yarn making process. In addition, the fluff generation site has a lower mechanical strength than that of the site where no fluff is generated, and the product is required to have poor mechanical quality. Furthermore, when fuzz is present in a package wound with a yarn, the appearance is not good.

  In addition, for example, if fuzz generated during the manufacturing process is wound around a guide or the like and accumulated, it will hinder the running of the yarn, and in a severe case, the running of the yarn becomes impossible. Moreover, if the fluff accumulated on the guide adheres to the running yarn gradually or at a stroke and flows to the subsequent process, the attached fluff causes further deterioration of the product quality.

  Therefore, conventionally, in Patent Documents 1 and 2, for example, when fluff occurs during yarn production, an attempt is made to prevent the occurrence of the above-described problem by detecting the occurrence of fluff. ing. However, in any of these conventional techniques, it is necessary to provide a device for detecting the occurrence of fluff very close to the running yarn.

  That is, in the technique proposed in Patent Document 1 (Japanese Patent Laid-Open No. 2002-180348), “the fluff is released from the running yarn by the centrifugal force generated when the running yarn changes the running direction, and this fluff is removed. "Technology for causing a fluff to be detected by its collision force by colliding with a fluff detection tip of a fluff detection device disposed so as to intersect and approach the travel path of the traveling yarn".

  Further, the technique proposed in Patent Document 2 (Japanese Patent Laid-Open No. 2003-301369) does not need to separate the fluff from the running yarn by centrifugal force as in Patent Document 1, but it still occurs. It remains the same as detecting that the fluff has contacted the sensing means. Therefore, the fuzz detection means must be provided close to the running yarn so that the fluff generated can be detected.

  As described above, in the conventional techniques proposed in Patent Documents 1 and 2 described above, when a factor such as occurrence of yarn breakage or device maintenance occurs or work such as re-threading is required, It is necessary to temporarily retract the fluff detection device that hinders the movement to a position that does not hinder the work. Then, after these operations are completed, it is necessary to adjust the reproducibility of fluff detection and the like after the retracted fluff detection device is returned to a predetermined position.

  Therefore, instead of the contact-type fluff detection technology that requires the fluff detection device to be installed close to the traveling yarn, a projector that projects light onto the traveling yarn, and the light projected from the projector is received. For example, Patent Document 3 (Japanese Patent Application Laid-Open No. 2004-316055) proposes a non-contact type fluff detection technique including a light receiver. In this prior art, the occurrence of fluff is detected by the amount of change in the amount of light generated by being blocked by the fluff generated on the running yarn.

  However, this prior art detects fluff by disposing a light projector and a light receiver facing each other in the axial direction of the roller (that is, the direction perpendicular to the traveling of the yarn). For this reason, when the speed of the running yarn is increased to 100 m / min or more, the running yarn crosses the light flux in an instant, so that it is very difficult to detect the change in the amount of light normally and accurately. For this reason, this conventional technique has a problem that the fluff detection can be performed satisfactorily only in a very low speed region of 10 m / min.

  In this prior art, light for detecting a change in the amount of light is projected onto the running yarn after the yarn running at high speed leaves the roller to detect fluff. For this reason, the yarn path of the running yarn is not regulated by the roller, and there is a problem that vibration occurs in the yarn because it runs freely.

  In this prior art, if vibration occurs in the running yarn, there is a problem that fluff cannot be accurately detected despite the presence of fluff due to the influence of vibration. In particular, when such running vibration occurs in a yarn that runs at a high speed of 100 m / min, it is very difficult to say that it is impossible to detect fluff.

JP 2002-180348 A (Claims) JP 2003-301369 A (Claims) JP 2004-316055 A (paragraphs [0012], [0020] and [0022])

  An object of the present invention is to solve various problems of the above-described prior art. That is, it is not necessary to provide a contact-type fluff detection device that detects the presence of fluff generated on the traveling yarn by contact with the fluff, and the yarn travels at a high speed of 100 m / min or more. It is intended to suppress false detection due to the influence of vibration or the like on the yarn even if the fluff is generated in the yarn. Another object of the present invention is to provide a fluff detection device and a fluff detection method capable of stably detecting fluff even when the yarn runs at high speed.

  Here, as means for solving the above-described problems, the fuzz detection device and the fuzz detection method described in the following (1) to (10) are provided.

(1) A laser that is aligned in one direction parallel to the yarn path direction of the yarn traveling on a roller in order to detect fluff generated by cutting the filaments constituting the multifilament yarn. A projector that projects a luminous flux;
A light receiver for receiving a light amount of the laser beam in a predetermined area at a preset sampling time interval (ΔT ₁ ) ;
At least a data processing device that performs a fluff detection process by calculating a light amount change amount generated by being blocked by the presence of the fluff from the light amount of the laser beam received by the light receiver ,
The data processing device is configured to obtain an average value of N light quantity data acquired at a time interval (ΔT ₂ ) that equally divides a sampling time interval (ΔT ₁ ) of a light quantity detected by the light receiver into N (N: positive integer). Alternatively, a fluff detection device provided with data smoothing means for representing light quantity data taken in at each sampling time interval (ΔT ₁ ) by a sum value .
(2) The data processing device
A light amount change calculating means for calculating a light amount change amount generated by being blocked by the presence of the fluff from the light amount of the laser beam received by the light receiver;
A light quantity change rate that calculates the light quantity change rate in real time as the difference between the latest calculated light quantity change quantity and the previously calculated light quantity change quantity for each light quantity change quantity sampled and calculated at regular time intervals. And a computing means of
Storage means for storing a threshold for determining the occurrence of fluff when the calculated light amount change rate exceeds a reference value;
A comparison means for comparing the light amount change speed with the threshold;
The fluff detection device according to (1), further comprising fluff determination means that determines that the occurrence of fluff is detected when the light amount change speed to be compared exceeds the threshold value.
( 3 ) The fluff detection device according to (1) or (2) , wherein the laser light is visible light.
( 4 ) The fluff detection device according to any one of (1) to ( 3 ), wherein the laser beam is a rectangular beam.
( 5 ) The fluff detection device according to any one of (1) to ( 4 ), further comprising counter means for counting the number of times the presence of fluff is detected by the data processing device.
( 6 ) The apparatus according to any one of (1) to ( 5 ), further comprising a stop unit that issues a stop signal to a device that supplies the yarn that runs on the roller when the presence of fluff is determined by the data processing device. The fuzz detection apparatus as described.
( 7 ) The fluff detection device according to any one of (1) to ( 6 ), further comprising an alarm unit that issues an alarm when the presence of fluff is determined by the data processing device.
( 8 ) In order to detect fluff generated by cutting the filaments constituting the multifilament yarn, the laser is aligned in one direction parallel to the yarn path direction of the yarn running on the roller. Project a luminous flux,
Receiving the light quantity of the laser beam having a constant area at every preset sampling time interval (ΔT ₁ ) ;
The amount of change in the amount of light caused by shading due to the presence of the fluff is represented as N light amount data at a time interval (ΔT ₂ ) that equally divides the sampling time interval (ΔT ₁ ) for capturing the light amount into N (N: positive integer) The acquired light amount data is smoothed and calculated according to the average value or the sum total value of the N pieces of data acquired ,
A predetermined threshold value is compared with the calculated light amount change amount to determine the presence of fluff, and it is determined that the occurrence of fluff is detected when the light amount change amount exceeds the threshold value. A method for detecting fuzz.
( 9 ) The fluff detection method according to ( 8 ), wherein the multifilament yarn travels on the roller at a speed of 200 to 1500 m / min.
( 10 ) The method for detecting fluff according to ( 8 ) or ( 9 ), wherein the supply of the yarn traveling on the roller is stopped when the occurrence of fluff is detected.
( 11 ) The fluff detection method according to any one of ( 8 ) to ( 10 ), wherein an alarm is issued when the occurrence of fluff is detected.
( 12 ) Count the number of times of detection each time the presence of fluff is confirmed, and count the number of fluff present in a certain length of yarn and / or in the wound yarn package after winding ( 8 ) to ( The fluff detection method according to any one of 11 ).
( 13 ) Stores the time when the presence of fluff was confirmed and the yarn package wound with the yarn where the fluff was detected, and specified the position of the fluff present in the yarn package based on the stored information. The fluff detection method according to any one of ( 8 ) to ( 12 ).
( 14 ) The threshold value is set in several stages, and the size of the fluff detected according to the amount of light shielded when the fluff passes is classified into a plurality of layers and output in layers ( 8 ) to ( 13 ) The fluff detection method according to any one of the above.

  First, according to the fluff detection device and the fluff detection method according to the present invention, the running yarn to be detected is supported on the roller. Therefore, the yarn runs on a certain yarn path regulated by the roller. For this reason, unlike the yarn that runs freely without being constrained by the roller, the yarn does not vibrate.

  Therefore, since the traveling yarn travels on a constant yarn path substantially without vibration, the position of the laser beam projected onto the traveling yarn is always kept constant. For this reason, the amount of light blocked by the yarn is always stable without being affected by disturbances such as yarn vibration, and erroneous detection of the amount of light is unlikely to occur.

  Moreover, the fluff detection device and the fluff detection method according to the present invention employs a non-contact type fluff detection method using a laser beam. For this reason, the fluff detection means can be provided at a position distant from the traveling yarn, and it is not necessary to install the fluff detection means close to the conventional technology.

  Then, when an operation such as re-threading the traveling yarn onto the roller occurs, the operation is not hindered even if the fluff detection device is temporarily retracted to a position where the operation is not hindered. Further, normally, the fluff detection device is not contaminated or the broken yarn end is not entangled with the fluff detection portion due to the scattering of the treatment agent or the like applied to the running yarn.

  Furthermore, since the fluff detection is performed by the laser beam, the malfunction is small, and the fluff detection accuracy is improved. If it does so, the generated fluff can be detected quickly and reliably, and quality control of the manufactured yarn can be carried out satisfactorily.

  In the present invention, the yarn to be subjected to fluff detection is a multifilament yarn composed of a plurality of filaments (long single fibers). At that time, the kind of such multifilament yarn is not particularly limited, such as a commonly used natural fiber, semi-synthetic fiber, and synthetic fiber. However, since the occurrence of fluff frequently occurs in the synthetic fiber drawing process, it is preferable to target synthetic fibers. Specifically, an acrylic fiber, a polyester fiber, a nylon fiber, an aramid fiber, an arylate fiber, or a carbon fiber can be preferably exemplified.

Hereinafter, embodiments of a fluff detection device and a fluff detection method according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic explanatory view (perspective view) showing an embodiment of a fluff detection device according to the present invention. In FIG. 1, the symbol Y is a multifilament yarn (hereinafter also simply referred to as “yarn”) composed of a plurality of filaments (long single fibers), and this yarn Y is composed of two rollers 1 (11 And 12). Reference numeral 2 denotes a transmissive laser light amount detector. The transmissive laser light amount detector 2 includes a projector 21 and a light receiver 22.

  As described above, in the present invention, as shown in the example of FIG. 1, while the yarn Y travels on the two rollers 1 (11 and 12), the yarn traveled by the roller 1. Y yarn path is in a state of being regulated to a certain level. Therefore, in the present invention, such a state is effectively utilized. That is, while the yarn Y travels on the roller 1 in the direction of the arrow shown in the figure, the yarn Y does not vibrate and utilizes the fact that the yarn travels stably on a predetermined yarn path (on the roller). To do.

  Next, the laser beam L having a certain area from the projector 21 of the transmission type laser light quantity detector 2 (with the presence in the drawing) with the yarn path of the yarn Y traveling stably on the roller 1 in between as described above. The light is projected toward the light receiver 22. In the example of FIG. 1, the laser beam L is projected onto the yarn path from the opposite direction to the running direction of the yarn Y. However, the laser beam L is projected in the forward direction with respect to the running direction of the yarn Y. Needless to say.

  Here, in the present invention, the laser light beam L needs to be a light beam having a constant area and aligned in one direction, and is a light beam state in which light is focused to a constant area without being diffused. It is necessary to propagate as it is. For this reason, in the present invention, it is preferable to use laser light having a single wavelength aligned in one direction as light for irradiating the yarn path.

  In general, laser light emitted from a semiconductor laser light transmitter provided in the projector 21 is transmitted toward the light receiver 22 as a parallel light beam state by a projector lens unit (not shown). And the laser beam which passed the slit by the side of the light receiver 22 is condensed on a light receiving element.

  At this time, the shape of the laser beam L projected from the projector 21 is, as described above, when the beam L is cut at a right angle with respect to the traveling direction of the beam L, the beam L is cut at any position. It is preferable that the cross-sectional area of is constant. This is because the influence of the installation distance between the projector 21 and the light receiver 22 can be reduced by doing so.

  That is, if there is an object (“fluff” in the present invention) that blocks the laser beam L in the parallel area of the projected laser beam L, regardless of the installation distance between the projector 21 and the light receiver 22, This is because as long as fluff is present between the light projector 21 and the light receiver 22, it is possible to detect a change in the amount of light satisfactorily. On the other hand, when the laser beam L is narrowed or diffused with a certain focal length, the installation positions of the projector 21 and the light receiver 22 need to be finely adjusted, and are reduced by being blocked by the object. It is not possible to detect the change in the quantity of light that is good and accurate.

  As described above, the light amount change detected by the light amount detector 2 is usually extracted in the form of an analog voltage output, for example. Then, the extracted analog signal (light quantity signal) is passed through an amplifier (amplifier) 3, an A / D converter (analog signal / digital signal converter) 4, interface means 5, etc., as illustrated in FIG. The data processing device 6 composed of a personal computer or the like is loaded as digital information. Then, the digital information taken into the data processing device 6 is subjected to data processing, so that the presence or absence of fluff generated on the traveling yarn Y is determined, and fluff detection is performed with good accuracy.

  As described above, the data processing device 6 performs data processing for determining the presence of the fluff F. The specific embodiment of the data processing device 6 need not be limited to the personal computer already described, but can be generally constituted by a commercially available computer such as a personal computer.

  Here, the data processing device 6 according to the present invention is provided with at least a storage means 61, a central processing unit (CPU: central processing unit) 62, and the like. Light amount comparison and light amount change calculation, fluff determination by comparison between an evaluation reference value (threshold value) and light amount change value, smoothing processing of light amount data, and the like are performed. Therefore, the CPU 62 also serves as a light amount change calculation unit, a comparison unit, a fluff determination unit, and a data smoothing unit in cooperation with the storage unit 61 and the like.

  Note that the storage means 61 provided in the data processing device 6 includes a semiconductor storage element such as a RAM (Random Access Memory) and a ROM (Read Only Memory), or a hard disk formed of a magnetic storage medium, for example. Has been. The storage unit 61 stores necessary information such as the detected light quantity determination method, a program necessary for performing the fluff detection process, and the like.

  Then, by executing the program stored in the storage unit 61, it is possible to process digitized data relating to the amount of light captured by the light receiver 22 through the interface unit 5 or the like. Thus, in the present invention, the presence of the fluff F generated on the traveling yarn Y by the data processing is determined.

Hereinafter, the “process for detecting fluff generated on the running yarn Y by detecting a change in the amount of light”, which is one of the main features of the present invention, will be described in detail with reference to FIGS.
FIG. 2 projects the laser beam L, which is aligned in parallel in one direction by the lens system provided in the projector 21, onto the yarn path of the yarn Y that runs on the roller 11 shown in FIG. FIG. 6 is a schematic explanatory view showing an embodiment in a case where a projected laser beam L is taken into a light receiving element from a slit (for example, a width of 10 mm and a height of 1 mm) provided in the light receiver 22. FIG. 2 is also a schematic cross-sectional view of an effective area (indicated by a one-dot chain line in FIG. 2) for detecting a light amount change of the laser beam L projected onto the roller 11 on which the yarn Y travels.

  In addition, as shown in FIG. 2, the running yarn Y is comprised from the some filament group. For this reason, the filament group that runs on the roller 11 is pressed by the roller 11 and spreads in a flat state as if it was crushed on the roller 11. In addition, in addition, in the example of FIG. 2, the running yarn Y shows a state where fluff has not yet occurred. When the yarn Y on which the fluff is not generated travels on the roller 11 as in this example, the amount of light detected by the light receiver 22 changes slightly due to the influence of disturbance or the like, but hardly changes. It moves at a certain level.

  By the way, the effective area (cross-sectional area of the light beam L) of the laser light beam L for detecting the light quantity change can be set as a rectangular area having a width of about 10 mm and a height of about 1 mm, for example. This dimension can be arbitrarily set by the slit shape provided in the above-described light receiver 22. However, it is needless to say that the effective area should be set to the selected optimum value by selecting an optimum value in advance through experiments or the like in accordance with the yarn making conditions.

  In the present invention, the reason why the length in the width direction of the effective area is made larger than the length in the height direction is as follows. That is, as already described, the yarn Y travels in a flat shape on a predetermined yarn path on the roller 11. Therefore, the traveling yarn Y does not vibrate in the vertical direction of the yarn path, but is not subject to any restriction from the roller 11 in the width direction of the yarn path. For this reason, since there is a possibility that the yarn path on which the yarn Y travels is shifted to some extent in the width direction, this result is taken into consideration.

  Next, a method for detecting fluff will be described in detail with reference to FIGS. 3 and 4 in the case where fluff is generated in the yarn Y that travels in a state where the fluff does not exist as illustrated in FIG. To do. In FIG. 3, symbol F indicates a fluff, and in this example, the fluff F is intertwined into a lump.

  Here, in FIG. 3, FIG. 3A is a normal state in which fluff F has not yet occurred, as in FIG. 2, and in FIG. 3B, fluff F is generated on the right side of the running yarn Y. 3 (c) shows a state where the fluff F is generated on the right side and the left side of the running yarn Y, and FIG. 3 (d) shows that the fluff F is generated on the upper side of the running yarn Y. FIG. 3 (e) shows a state where the fluff F is generated between the yarn Y and the roller 1 below the traveling yarn Y, respectively.

  In FIG. 3, the details will be described later, but the cases of FIGS. 3B and 3C are cases where the presence of the fluff F can be detected satisfactorily. Further, the case of FIG. 3D is a case where the fluff F cannot be normally detected in the illustrated state, but can be detected by changing the setting of the fluff detection device. The case shown in FIG. 3 (e) is a case where it is difficult to detect the fluff F because the fluff F is caught in the yarn Y.

  Note that the case of FIG. 3D is a case where the fluff F cannot be detected because the position of the fluff F is out of the effective range for detecting the fluff F. However, the fluff F can be detected satisfactorily by expanding the detection range of the fluff F to the upper part. That is, in this case, the fluff F can be detected by expanding the detection range of the fluff F in the height direction.

  As described above, the present invention is characterized by detecting fluff present on the yarn Y traveling on the roller 1. At this time, since the traveling yarn Y is supported by the roller 1, the movement is restricted on the yarn path and does not vibrate up and down. If it does so, it will be released from the vibration of the yarn Y, and the detection of the fluff F can be performed stably and accurately in a state where there is less disturbance.

  The roller 1 on which the yarn Y travels does not need to be particularly limited in its material, surface condition, etc., as long as it has a diameter, width and strength sufficient for the yarn Y to travel stably. Further, the roller 1 on which the yarn Y travels may be a free roller that is driven by frictional force with the yarn Y, or a forced drive roller that is forcibly driven by an electric motor or the like.

  However, in the case of a fixed roller that does not rotate, the friction between the running yarn and the roller is increased, and fluff is generated. Only if. However, as long as the condition that the running yarn Y is not damaged is satisfied, there is no reason to limit even the fixed roller or the fixed guide.

  Next, FIG. 4 will be described. FIG. 4 is a bar graph showing the ratio of the amount of light that is blocked and does not reach the light receiver 22 with respect to the total amount of light projected into an effective area of a certain area received by the light receiver 22. The left bar graph shows the case where the fluff F does not exist, and the right bar graph shows the case where the fluff F exists.

  As is apparent from the left bar graph shown in FIG. 4, the amount of light that has not reached the light receiver 22 is the amount of light blocked by the roller 11 and the yarn when the fluff F is not present on the traveling yarn Y. Y is the total amount of blocked light, and the light amount obtained by subtracting the blocked light amount is detected by the light receiver 22.

  On the other hand, when the fluff F is generated in the running yarn Y as shown in the bar graph on the right side of FIG. 4, the amount of light blocked by the fluff F does not reach the light receiver 22 further. Therefore, in this case, the amount of light received by the light receiver 22 is reduced by the amount of light blocked by the fluff F, as compared with the case of the right bar graph.

  Therefore, in the fluff detection device and the fluff detection method according to the present invention, as described below, the data processing device 6 calculates the light amount change amount blocked by the presence of the fluff F from the light amount detected by the light receiver 22. . Then, when the calculated amount of change in the light amount exceeds the threshold, it is determined that the fluff F exists, and when it does not exceed the threshold, it is determined that the fluff F does not exist.

This fluff determination is performed based on the steps described below.
First, the light receiver 22 receives a laser beam L projected at a preset sampling time interval (ΔT ₁ ). Then, the received light quantity (for example, analog voltage value) is amplified by an amplifier (amplifier) 3 as necessary, and then converted into a digital signal through an A / D converter 4. Next, the data is taken into the data processing device 6 through the interface means 5.

Needless to say, the sampling time interval (ΔT ₁ ) is preferably as short as possible in order to increase the speed of fluff detection under the condition that the fluff detection process is set to a time interval that allows the fluff detection process to be sufficiently performed. This sampling time interval (ΔT ₁ ) is within the range of the experiment conducted by the present inventor, but 0.6 to 2.0 in consideration of the traveling speed of the yarn Y (100 to 3000 m / min). It has been found preferable to set in the msec range.

In the present invention, a time interval (ΔT ₂ ) for dividing the sampling time interval (ΔT ₁ ) into N (N: positive integer) is set between the constant sampling time intervals (ΔT ₁ ). Then, it is preferable that N light quantity data groups are sampled every set time interval (ΔT ₂ ) and sequentially stored in the storage unit 61. Therefore, ΔT ₁ and ΔT ₂ satisfy the relational expression ΔT ₂ = ΔT ₁ / N.

Next, during the time interval (ΔT ₂ ) for dividing the sampling time interval (ΔT ₁ ) by N, an average value of N light amount data captured by the CPU 62 (data smoothing means) is obtained, and this light amount average value is obtained. This is represented as light amount data at the sampling time interval (ΔT ₁ ). In this case, instead of calculating the average value, the total amount of light obtained at every time interval ΔT ₂ may be calculated and this total may be represented.

By doing so, when light amount data is collected at a short time interval (ΔT ₂ ), a large amount of noise is mixed, and the fluff F is present even though the fluff F is not generated. False detection is reduced. In addition, the possibility that the fluff detection device malfunctions due to factors other than the presence of fluff that should be detected, such as the influence of the fine vibration of the yarn Y, can be drastically reduced.

  As a result, the malfunction detection of the fluff F can be avoided, and an accurate light quantity change can be calculated accurately and stably. Therefore, it is preferable not only in quality control of the yarn Y but also in that unnecessary work required for the operation and fine adjustment of the fluff detection device itself can be saved.

Note that ΔT ₁ / ΔT ₂ is preferably 2 to 10. This is because if ΔT ₁ / ΔT ₂ is 1, there is no significance in setting the short sampling time interval (ΔT ₂ ). On the other hand, when ΔT ₁ / ΔT ₂ exceeds 10, even if fluff F is actually detected, if the size of fluff F is small, a lot of light quantity data is detected even though fluff F is detected. The amount of light of the fluff F detected inside is buried, and its contribution is diminished. In this case, there is a possibility that a malfunction may occur that the fluff F is detected but not detected.

  In this case, finer detection of the fluff F can be expected as the speed at which the yarn Y travels is set slower and the time interval is shortened. However, in consideration of the detection limit (resolution) of the fluff F while ensuring the productivity of the yarn Y, the traveling speed of the yarn Y is 100 m / min or more, preferably 100 to 3000 m / min. A particularly preferable range is 200 to 1500 m / min.

Next, the light quantity data taken into the data processing device 6 at the constant short sampling time interval (ΔT ₂ ) described above is sequentially stored in the storage means 61, and at the same time, at every sampling time interval (ΔT ₁ ). Representative light quantity data is calculated. In this way, when the representative light quantity data is calculated for each sampling time interval (ΔT ₁ ), the CPU 62 (light quantity change calculating means) determines whether or not the latest representative light quantity value has changed due to the presence of the fluff F. to decide. For this purpose, the latest representative light quantity value and the representative light quantity value calculated one step before the latest (at the time of data sampling immediately before the latest) are read from the storage means 61, and these light quantity values are subtracted. To calculate the amount of light change in real time.

  That is, normally, when the fluff F does not block the laser beam L (when there is no fluff), the amount of light blocked by the yarn (Y) and the roller (11) as illustrated in the bar graph on the left side of FIG. The total of the above changes substantially without any change except for minute fluctuations made up of disturbance factors. Therefore, the light amount change amount calculated by the CPU 62 (light amount change calculating means) is almost zero.

  However, as shown in the bar graph on the right side of FIG. 4, if the fluff F exists, the amount of light captured by the light receiver 22 is reduced by the amount of light blocked by the fluff F. Then, as already described, only the amount of light blocked by the fluff F is used as the amount of light amount change, and the difference is calculated by the CPU 62 (light amount change calculating means).

  Therefore, it can be determined that the fluff F is present when the change in the amount of light is detected at a level exceeding the determination reference value (threshold value). As described above, when the calculated amount of change in the light amount is smaller than the determination reference value, the advantage of determining that the fluff F is present is that even if the light amount is small even for a reason other than the presence of the fluff F. When it changes, it is possible to avoid the occurrence of false detection that the fuzzy F is erroneously detected.

  Therefore, as indicated by a dotted line on the left bar graph in FIG. 4, a “threshold value for fluff determination” serving as a reference value for determining the presence of fluff F is provided and stored in the storage means 61. deep. Then, the CPU 62 (comparing means) compares the light quantity change amount calculated from the light quantity data sampled by the CPU 62 (light quantity change calculating means) with the threshold value stored in the storage means 61. As a result of the comparison, when the calculated amount of change in the light amount exceeds the threshold value, it is determined that the fluff F is detected by the CPU 62 (fluff determination means).

  At that time, if the threshold is not exceeded, it is determined that the fluff F has not been detected. Therefore, the threshold value needs to be set carefully. Normally, it is desirable to set an optimum threshold value by searching for a value that reduces false detection of the fluff F by sufficient experiments.

  At this time, it is preferable that the fluff detection device includes counter means for counting the number of times each time the presence of the fluff F is confirmed by the fluff determination means. In this way, the number of fluff F present in the fixed length yarn Y or in the wound yarn package after winding is accurately counted. Then, it is a preferred embodiment that the number of times counted is stored in the storage means so that this information can be taken out.

  Furthermore, it is also a preferred embodiment that the threshold value is set in several stages, and the fluff sizes detected according to the amount of light shielded when the fluff F passes are classified into a plurality of layers and output. . Specifically, for example, a fluff F having a size that greatly affects quality, a fluff F having a moderate effect size, and a fluff F having a small effect size is described in three stages. It is preferable to classify and perform appropriate treatment for each yarn Y in which the fluff F is detected, depending on the size of the fluff F.

  It is also preferable that the fluff detection device stores the travel start time of the traveling yarn Y, the travel speed, and the time when the fluff F is detected in the storage unit 61 in conjunction with the fluff detection. It is. In this case, it is possible to easily identify at which position of the yarn package after being wound by a winder or the like the fluff F detected by the fluff detection device based on the stored numerical value. Then, for example, when the yarn is unwound from the yarn package later, the generation position of the fluff F can be easily identified by visual observation or the like.

  Furthermore, in the present invention, when the presence of fluff is determined by the data processing device 6, there is provided stop means for issuing a stop signal for stopping a driving device (not shown) for supplying the traveling yarn to the roller 1. It is also preferable. This is because by stopping the running of the yarn, it is possible to easily and quickly classify the yarn having the fluff and the yarn not having the fluff, which is preferable in quality control of the yarn.

  It is also preferable that an alarm device (not shown) that issues an alarm when the presence of fluff is determined by the data processing device 6 is provided. This is because, by issuing an alarm, it is possible to easily and quickly stratify the yarn package having the fluff and the yarn package not having the fluff in the wound yarn package unit. This is because it is preferable in management. The alarm includes an alarm sound, an alarm lamp that lights or blinks light, or an alarm communicator that transmits an alarm signal using a wired or wireless communication device.

  In addition, according to the present invention, it is possible to save the trouble of periodically cleaning the fluff detection device, and it is possible to perform continuous operation for a long time. In addition, the fluff detection device can be provided at a position away from the rotating body such as the running yarn and the roller, and it is necessary to retreat to a position that hinders the work as it hinders the work again such as re-threading. Lost.

  In the embodiment described above, the case where the number of the yarns Y traveling on the roller 1 is described has been described. However, a plurality of yarns may travel on the roller 1. For example, in such a case, there is no problem even if a fluff detection device according to the present invention is provided for each yarn path along which each yarn travels to detect fluff.

Hereinafter, the fluff detection method of the present invention will be described with reference to examples.
Multifilament yarn made of para-type wholly aromatic polyamide fiber (trade name: Technora, manufactured by Teijin Techno Products Co., Ltd.) whose total fineness after winding is 1670 dtex (1000 filaments) Articles were used. Then, after being entangled by passing through a compressed air nozzle, as illustrated in FIG. 1, a multifilament yarn made of the above fibers on a free roller having a diameter of φ20 mm that is driven and driven by the frictional force of the yarn. Run the strip. At this time, the running speed of the yarn is set to each level of 200 m / min, 500 m / min, 650 m / min, 1000 m / min, and 1500 m / min, and the fluff generated on the yarn at each set level is set. Detection was performed.

  At this time, a laser type of a smart sensor (trade name) manufactured by OMRON Corporation, in which a projector and a light receiver are set, was used as a transmissive laser light amount detector for projecting and receiving a laser beam. Specifically, the sensor head part type: ZX-LT0110 and the amplifier unit part type: ZX-LDA11-N were used. Note that a visible light laser having a wavelength of 650 nm is transmitted from the projector of the transmission type laser light amount detector.

At that time, the distance between the projector and the light receiver is set to 200 mm, and the laser beam from the projector is opposite to the yarn traveling direction with respect to the yarn path of the yarn traveling on the roller near the middle. It was arranged so that it could be flooded. In addition, the thing with the rectangular area 10mm < ² > of width 10mm and height 1mm was used for the laser beam aligned in parallel to one direction which projects on a thread. However, the shape of the light beam must be larger than the area that can completely cover the cross section of the yarn running on the roller, and the type and shape of the yarn, or the yarn production conditions (running of the yarn) Usually, a rectangle having a width of 1 to 50 mm and a height of 1 to 50 mm is preferable.

  Next, the transmission type laser light amount detector is installed through an interface unit (ZX-SFW11V3) manufactured by OMRON Corporation, and a Microsoft OS (Windows (registered trademark) XP) in which spreadsheet software is installed is installed. It was connected to a commercially available personal computer (CPU operating clock of 2 GHz or more). This personal computer has a program for recognizing the presence of fluff in real time from the light amount data collected at a constant sampling time interval (0.54 msec interval) by the transmission laser light amount detector. It was created and stored in a hard disk (storage means) attached to the personal computer.

At this time, the threshold value (light quantity area value blocked by the generated fluff) for determining the presence of fluff generated on the yarn traveling on the roller was set to 1.5 mm ² . The range This threshold was set to 1.5 mm ² in this embodiment, according to the experiments conducted by the present inventors, the range of 0.4 to 2.0 mm ^2, particularly preferably of 0.5 to 1.0 mm ² It was confirmed that the fluff having a certain size can be detected satisfactorily at the running speed of the yarn at each level described above.

  Under the conditions described above, the fluff was detected with the distance between the traveling yarn, the laser beam projector and the light receiver being separated, and as a result, the fluff could be detected with high sensitivity. For this reason, even if a large amount of fluid material such as oil that adheres to the running yarn is scattered around, the laser projector and receiver are not contaminated by these scattered objects. Fluff was detected with good time sensitivity.

  When the presence of fluff is detected as described above, the time when the presence of the fluff is confirmed, the yarn package around which the fluff is detected and the number of occurrences are stored and stored in advance. Bad patch cages and good packages were categorized according to the number of fuzz produced per fixed length. Further, the distance from the fluff detection position to the winder was calculated from the yarn traveling speed and the yarn package winding start time stored at the same time. Then, taking this distance into consideration, the information was used to confirm at which position of the yarn package around which the yarn with the fluff was wound was present.

It is a schematic explanatory view (perspective view) showing an embodiment of a fluff detection device according to the present invention. It is also a schematic cross-sectional view of an effective area for detecting a light amount change of a laser beam projected on a roller on which a yarn travels. It is explanatory drawing which illustrated typically the state of the fluff which generate | occur | produces in the running yarn. It is drawing for demonstrating the change of the light quantity by which a laser beam is interrupted | blocked by the presence or absence of fluff.

Explanation of symbols

1 (11, 12): Roller 2: Transmission type laser light quantity detector 21: Projector 22: Light receiver 3: Amplifier (amplifier)
4: A / D converter 5: Interface means 6: Data processing device 61: Storage means 62: Central processing unit (CPU)
L: Laser beam Y: Traveling yarn

Claims (14)

In order to detect fluff generated by cutting the filaments constituting the multifilament yarn, a laser beam aligned in one direction is projected with respect to the yarn path direction of the yarn traveling on the roller. A light projector,
A light receiver for receiving a light amount of the laser beam in a predetermined area at a preset sampling time interval (ΔT ₁ ) ;
At least a data processing device that performs a fluff detection process by calculating a light amount change amount generated by being blocked by the presence of the fluff from the light amount of the laser beam received by the light receiver ,
An average value of N light quantity data acquired by the data processing apparatus at a time interval (ΔT ₂ ) that equally divides the sampling time interval (ΔT ₁ ) of the light quantity detected by the light receiver into N (N: positive integer). Alternatively, a fluff detection device provided with data smoothing means for representing light quantity data taken in at each sampling time interval (ΔT ₁ ) by a sum value . The data processing device is
A light amount change calculating means for calculating a light amount change amount generated by being blocked by the presence of the fluff from the light amount of the laser beam received by the light receiver;
A light quantity change rate that calculates the light quantity change rate in real time as the difference between the latest calculated light quantity change quantity and the previously calculated light quantity change quantity for each light quantity change quantity sampled and calculated at regular time intervals. And a computing means of
Storage means for storing a threshold for determining the occurrence of fluff when the calculated light amount change rate exceeds a reference value;
A comparison means for comparing the light amount change speed with the threshold;
The fluff detection device according to claim 1, further comprising fluff determination means that determines that generation of fluff is detected when a light amount change speed to be compared exceeds the threshold. The laser light is visible light, fluff detection device according to claim 1 or 2. The fluff detection device according to any one of claims 1 to 3 , wherein the laser beam is a rectangular beam having a certain area. The presence of fluff by the data processing apparatus comprising a counter means for counting the number of times each time it is detected, fluff detecting device according to any one of claims 1-4. The fluff detection device according to any one of claims 1 to 5 , further comprising a stop unit that issues a stop signal to a device that supplies a yarn that travels on a roller when the presence of fluff is determined by the data processing device. . The fluff detection device according to any one of claims 1 to 6 , further comprising alarm means for issuing an alarm when the presence of fluff is determined by the data processing device. In order to detect fluff generated by cutting the filaments constituting the multifilament yarn, a laser beam aligned in one direction is projected with respect to the yarn path direction of the yarn traveling on the roller. Light
Receiving the light quantity of the laser beam having a constant area at every preset sampling time interval (ΔT ₁ ) ;
The amount of change in the amount of light caused by shading due to the presence of the fluff is represented as N light amount data at a time interval (ΔT ₂ ) that equally divides the sampling time interval (ΔT ₁ ) for capturing the light amount into N (N: positive integer). The acquired light amount data is smoothed and calculated according to the average value or the sum total value of the N pieces of data acquired ,
A predetermined threshold value is compared with the calculated light amount change amount to determine the presence of fluff, and it is determined that the occurrence of fluff is detected when the light amount change amount exceeds the threshold value. A method for detecting fuzz. The fluff detection method according to claim 8 , wherein a speed at which the multifilament yarn travels on the roller is 200 to 1500 m / min. The method for detecting fuzz according to claim 8 or 9 , characterized in that when the occurrence of fluff is detected, the supply of the yarn running on the roller is stopped. The method for detecting fluff according to any one of claims 8 to 10 , wherein an alarm is issued when the occurrence of fluff is detected. Counting the number of detection times each time the fluff present is confirmed, to count the fluff number present in the yarn package after the yarn during and / or take-up of fixed length, one of claims 8-11 The method for detecting fuzz described in 1. The time when the presence of fluff is confirmed and the yarn package wound with the yarn where the fluff is detected are stored, and the position of the fluff existing in the yarn package is specified based on the stored information. Item 13. A method for detecting fluff according to any one of Items 8 to 12 . Setting the threshold in several stages, fluff plurality output classification and stratification to the fluff size detected in accordance with the magnitude of the shielded light amount when passing, to any one of claims 8 to 13 The fuzz detection method described.

Images