CH707392A2 - Method for operating yarn cleaner used in spinning point of air spinning machine for spinning yarns on spool, involves removing yarn from measuring field of measuring head immediately after detection of invalid yarn defect - Google Patents

Abstract

The method involves detecting (203) an invalid yarn defect in a yarn, which is moved through a measuring field of a yarn cleaner measuring head along a longitudinal direction. Decision is made (204) whether the yarn defect is available or not due to a preset criterion. The yarn is left (211) in the measuring field immediately after detection of the invalid yarn defect. The yarn is removed (221) from the measuring field immediately after detection of another invalid yarn defect. The measuring head is adjusted (222) to zero when the yarn is removed from the measuring field. An independent claim is also included for a yarn cleaner.

Description

AREA OF EXPERTISE

The present invention is in the field of quality control of yarn. It relates to a method for operating a yarn cleaner and a workstation of a textile machine, according to the preambles of the independent claims. Furthermore, it relates to a corresponding yarn cleaner, according to the preamble of another claim.

STATE OF THE ART

To ensure the yarn quality so-called yarn cleaners are used on spinning and dishwashers. A yarn cleaning system includes a measuring head with at least one sensor which scans the moving yarn in a measuring field. WO-2010/063 128 A1 gives an example of a yarn cleaner measuring head. Commonly used sensor principles are the capacitive one (see for example EP-0 924 513 A1) or the optical one (see for example WO-93/13 407 A1). The aim of yarn cleaning is to detect yarn defects such as thick spots, thin spots or foreign substances in the yarn, to evaluate them according to certain quality criteria and to clean them from the yarn.

Immediately after the detection of a yarn defect, the yarn run is usually interrupted, e.g. by an interruption of the fiber supply (on a spinning machine) or by a cleaner cut (on a winding machine). An interruption of the yarn run causes the yarn to leave the measuring field of the measuring head. Then, a yarn end wound on a bobbin is searched, the defective yarn section is rewound and cut out, the cleaned yarn is reinserted into the measuring field and production is resumed. Timeouts in which no yarn is in the measuring field are used for a zero point adjustment (see WO-2010/043 063 A1) and / or for an adjustment (compare WO-2012/031 367 A1) of the measuring head, ie are from the Garnreinigerseite desired. However, the time-outs also lead to lower productivity, because during the off-hours, the job in question stands still for a long time. In this respect, the interruption of the yarn run from the production side is undesirable.

From CH-705 147҈A2 and WO-2013/010 278 A1 devices and methods for removing a yarn from the measuring field of a Garnreinigermesskopfes and reintroducing the yarn in the measuring field are known. The removal of the yarn from the measuring field can e.g. allow zero adjustment and / or adjustment of Garnreinigermesskopfes.

EP-1 238 937 A1 proposes to suppress an immediate cutting out in the event of an accumulation of defects in the yarn, in order then to cut out several defects at the same time. As a result, on the one hand, the number of splices is reduced, on the other hand, the processing speed is increased, since several defects are cut out simultaneously in a single cleaning step.

EP-A-2 573 228 A2 discloses a spinning station with a yarn discharge which is at least partially disposed between an exit of a spinning device and a winding device and with the aid of which an end section of the yarn produced is separable from the remaining yarn and dischargeable. After the detection of a yarn defect by means of a yarn cleaner arranged between the spinning device and the winding device, the yarn production is slowly throttled and finally interrupted. When the yarn end passes a monitoring unit, all units of the spinning station are completely stopped. The yarn end is now located at a defined position and can be detected by the Garnendenabführung without further handling means are necessary.

PRESENTATION OF THE INVENTION

It is an object of the present invention to provide a method for operating a yarn cleaner or a textile machine, which shows a way out of the conflict of objectives described above. The method should thus allow zero adjustments and / or adjustments of the measuring head, without unduly affecting the productivity. Another object is to provide a corresponding yarn cleaner.

These and other objects are achieved by the inventive method and the yarn cleaner as defined in the independent claims. Advantageous embodiments are given in the dependent claims.

According to the invention, the yarn is not removed from the measuring field for all inadmissible yarn defects, but only for some, while it is left in the measuring field for other yarn defects. If, on the one hand, the yarn is removed from the measuring field after the detection of an inadmissible yarn error, a zero point adjustment and / or an adjustment of the measuring head can be carried out. On the other hand, if the yarn is left in the measurement field after the detection of an improper yarn defect, the time-out in question takes less time than when the yarn is removed from the measurement field because the yarn end is not searched for on the spool. Thus, the time-outs are shortened over the prior art and increases productivity.

The invention relates to a method for operating a yarn cleaner, which includes a Garnreinigermesskopf with a measuring field for receiving a yarn. In the yarn moved through the measuring field along its longitudinal direction, impermissible yarn defects are detected. Immediately after the detection of at least one first improper yarn defect, the yarn is left in the measurement field, and immediately after the detection of at least one second improper yarn defect, the yarn is removed from the measurement field.

The invention also relates to a method for operating a workstation of a textile machine, for example a spinning or winding machine, which is equipped with a Garnreinigermesskopf with a measuring field for receiving a yarn. In the yarn moved through the measuring field along its longitudinal direction, impermissible yarn defects are detected. Immediately after the detection of at least one first improper yarn defect, the yarn is left in the measurement field, and immediately after the detection of at least one second improper yarn defect, the yarn is removed from the measurement field.

In a preferred embodiment, the measuring head is adjusted to zero and / or adjusted when the yarn is removed from the measuring field after the detection of the at least one first improper yarn error.

In one embodiment, it is decided on the basis of a predetermined first criterion whether an impermissible yarn fault is present or not. A parameter value measured on the yarn, on the one hand, and the extent of the measured parameter value in the longitudinal direction of the yarn, on the other hand, can be included in the predetermined first criterion.

In one embodiment, each improper yarn fault is cleaned immediately after its detection from the yarn.

In a further embodiment, it is decided on the detection of an improper yarn error due to a predetermined second criterion, whether the yarn is removed from the measuring field or not. Detected impermissible yarn defects can be characterized with at least one error parameter in each case, and the at least one error parameter enters into the predetermined second criterion. An error parameter is preferably an error length measured in the longitudinal direction of the yarn. According to the predetermined second criterion, the yarn is e.g. then removed from the measuring field when the error length exceeds a predetermined limit.

The invention further relates to a yarn cleaner. The yarn cleaner according to the invention comprises a measuring head, which comprises a sensor with a measuring field for receiving a yarn, and an evaluation unit for evaluating an output signal of the sensor, wherein the evaluation comprises a detection of impermissible yarn defects. The evaluation unit is set up to cause the yarn to remain in the measuring field immediately after the detection of at least one first unacceptable yarn defect and to initiate a removal of the yarn from the measuring field immediately after the detection of at least one second unacceptable yarn defect.

The evaluation unit is preferably set up to match the measuring head to zero and / or adjust when the yarn is removed from the measuring field after the detection of the at least one second improper yarn error.

In one embodiment, the evaluation unit is set up to decide on the basis of a predetermined first criterion whether an impermissible yarn fault is present or not.

The evaluation unit may be adapted to cause a cleaning of the yarn error from the yarn immediately after the detection of each improper yarn error.

In a further embodiment, the evaluation unit is adapted to decide upon the detection of an improper yarn error due to a predetermined second criterion, whether the yarn is removed from the measuring field or not. The evaluation unit may also be configured to characterize detected impermissible yarn defects, each with at least one error parameter, wherein the at least one error parameter is included in the predetermined second criterion.

TITLE OF DRAWINGS

The invention will be explained in detail with reference to the schematic drawing. <Tb> FIG. 1 <SEP> shows a schematic side view of a spinning machine according to the invention. <Tb> FIG. 2 <SEP> shows a flow chart of an embodiment of the method according to the invention. <Tb> FIG. 3 <SEP> shows a schematic side view of a yarn defect. <Tb> FIG. 4 <SEP> shows an event field for yarn events with a package and a cleaning boundary.

EMBODIMENT OF THE INVENTION

Fig. 1 shows a schematic side view of a spinning station 1 of an air-spinning machine, as it is known from EP-2 573 228 A2. As a rule, the air-spinning machine comprises a large number of such spinning stations 1, which are arranged one behind the other and perpendicular to the plane of the drawing.

The air-spinning machine has Uber designed as a drafting delivery device 11, which is supplied with a fiber material 91, for example in the form of a relined conveyor belt. Furthermore, the spinning station 1 shown has a spreader 12 spaced apart from the delivery device 11 with an inlet for the fiber material 91 and an internal air vortex chamber (not shown). Within the air swirl chamber, the fiber material 91 is provided for producing desired yarn 92 in a known manner with a rotation. The rotation is produced by a targeted air flow in the region of a spindle tip, wherein the air flow is generated by air nozzles which open tangentially into the air swirl chamber.

Furthermore, the spinning station 1 shown comprises a trigger device 15 formed by a pair of withdrawal rollers. The take-off roller pair is followed by a winding device 16 for winding up the yarn 92 withdrawn from the spinning station 1. The winding device 16 has a replaceable coil 19. The spool 19 can be rotated via a winding roller 18 in rotation. The yarn 92 is reciprocated during winding on the spool 19 by means of a yarn traversing device 17 in a direction perpendicular to the drawing plane to prevent unilateral spooling of the yarn 92.

The spinning station 1 is equipped with a Garnreinigermesskopf 13, which detects impermissible yarn defects. The yarn cleaner measuring head 13 is arranged between the spinning device 12 and the take-off device 15. Such a yarn cleaner measuring head 13 is known from the prior art and need not be described in detail here. In Fig. 1, a measuring field 14 of a sensor is shown, which serves to receive the yarn 92. The sensor can operate on the capacitive, the optical and / or another measuring principle. The yarn cleaner measuring head 13 also includes an evaluation unit (not shown) for evaluating an output signal of the sensor. The yarn cleaner measuring head 13 is preferably part of a yarn cleaning system with a plurality of measuring heads, one of which is arranged in each spinning station 1, and a (not shown) central control unit.

In addition, the spinning station 1 comprises a suction unit for sucking faulty end portions of the yarn 92, a cutting unit for separating these end portions and a loading unit for inserting unwound yarn in the spinning device 12. These elements are also known per se from the prior art , They are not shown in Fig. 1, nor are they described here in detail.

The spinning station 1 shown in Fig. 1 and described above is only one possible example of the application of the invention and is not intended to limit the generality of the invention. Upstream of the yarn cleaner measuring head 13, instead of the delivery device 11 and the spinning device 12, e.g. a texturing unit, a twisting unit, a cop or a spool may be mounted. The winding device 16 can be designed differently. It is not necessary that a winder 16 is located at all downstream of the yarn cleaner measuring head 13. In general, it is sufficient if there is a yarn source "upstream of the yarn cleaner measuring head 13 and a" yarn sink "downstream of the yarn cleaner measuring head 13.

FIG. 2 shows a flow chart of an embodiment of the method according to the invention.

After a production recording 201 errors in the yarn 92 are detected 203 using the Garnreinigermesskopfes 13 (see Fig. 1). On the basis of a predetermined first criterion, the detected yarn defects are checked for their admissibility 204. An example of the first criterion is on the occasion of Fig. 4 indicated. If there is an improper yarn error, the yarn error is characterized 205 with an error parameter. an error length L, as explained below with reference to FIGS. 3 and 4. The yarn run is interrupted 206 after the detection of an improper yarn fault 206. The term "yarn run interruption" 206 is understood to mean yarn stopping and yarn 92 separating upstream of the yarn cleaner measuring head 13. In the spinning station 1 according to FIG. 1, the yarn run is interrupted 206 by the supply of fiber material 91 to the spinning device 12 is interrupted and thus the spinning process is stopped. On the basis of a predetermined second criterion, it is then decided 206 whether yarn 92 is removed from measuring field 14 of yarn cleaner measuring head 13 221 or not 211. The error parameter can enter into the second criterion. The second criterion may be, for example: If the error length L exceeds a predetermined limit value, the yarn 92 is removed from the measuring field 14, otherwise not.

If the yarn 92 is not removed from the measuring field 14, the yarn 92 is left in the measuring field 14 of the yarn cleaner measuring head 13 211. Relative to the spinning station 1 according to FIG. 1, this means that the yarn 92 must come to a standstill, before a yarn end passes the measuring field 14. The yarn 92 is rewound 213 and the defect cleaned 214 by the faulty end portion is separated by the cutting unit. Subsequently, the production can be resumed 201 by the yarn end inserted into the spinning device 12 and a piecing process is performed. This can be done with the help of a service robot, a spinning mill's own yarn handling device or manually. All of these steps can be done relatively quickly, so productivity does not suffer greatly.

In the other case, the yarn 92 is removed from the measuring field 14 221. This is done by the yarn 92 is withdrawn so far after the spinning process by the discharge device 15 and wound on the spool 19 until a yarn end passes the measuring field 14 Has. When the measuring field 14 is empty. the yarn cleaner gauge 13 is adjusted to zero and / or adjusted 222 as described in the prior art. The yarn 92 is rewound 223 and the defect cleaned 224. The rewinding 223 and cleaning 224 is preferably parallel to the zeroing and / or the adjustment 222; alternatively, however, these steps may be performed sequentially. The yarn 92 is inserted again into the measuring field 14 225, whereupon the production can be resumed 201.

In an alternative embodiment to that of FIG. 2, the yarn run is not interrupted after the detection 203 of an impermissible error 93, but the yarn 92 continues to run. As in FIG. 2, immediately after the detection 203 of the impermissible error 93, it is decided 207 whether yarn 92 is left in the measuring field 14 211 or not 221, in the latter case. In the latter case, the yarn 92 can be replaced by a yarn lifting device such as a yarn lifting device it is known from the CH-705 147 A2, removed from the measuring field 14 221 and again inserted into the measuring field 14 2 225.

Figs. 3 and 4 serve to better understand the above-mentioned first and second criteria. In Fig. 3, a portion of the yarn 92 is shown schematically with a yarn defect 93. Yarn defect 93 is a thick spot in this example. The thick patch 93 has an average diameter D that is greater than the nominal diameter of the yarn 92. It extends over a length L, measured in the longitudinal direction of the yarn 92.

Fig. 4 shows a two-dimensional event field 4 for yarn events defined by their yarn parameter value AD and their extent L along the yarn longitudinal direction. Accordingly, the event field 4 is spanned by the yarn parameter AD (ordinate 42 or 42) on the one hand and its extension L along the yarn longitudinal direction (abscissa 41) on the other. The yarn parameter AD in this example is a deviation from the nominal diameter of the yarn 92, which is positive for thick spots, negative for thin spots. Alternatively, the diameter D itself could be plotted on the ordinate 42, 42. The yarn parameter may also be different. e.g. a yarn mass per unit length, a Garnretlektivität etc. In the event field 4 of Fig. 4, a so-called package 43 is shown as a contiguous surface, which is formed by the actual yarn 92 associated events. Furthermore, a cleaning limit 44 for thick places and a cleaning limit 44 for thin places can be seen in FIG. All elements shown in FIG. 4 are known per se, for example from WO-2010/078 665 A1.

The above-mentioned first criterion relates to the permissibility of yarn defects 93. In the example of FIG. 4, the cleaning limit 44, 44 is given: Yarn events which are below the thickening cleaning limit 44 are permissible, while yarn defects 93. which are above the cleaning limit 44 for thick places, are inadmissible (and vice versa for thin sites).

On the basis of the above-mentioned second criterion, it is decided whether or not the yarn 92 is removed from the measuring field 14. Error parameters, such as the error diameter D discussed in connection with FIG. 3, the error length L, etc., can be included in the second criterion. In particular, there may be types of errors according to which a zero point adjustment and / or an adjustment are advantageous. Such error types include the so-called yarn number errors, d. H. Garnfehler 93 with a extraordinarily large error length L. Alternatively or in addition to an error parameter but the second criterion may depend on other parameters and circumstances. In one embodiment, a time elapsed since the last zero offset and / or the last adjustment 222 may be included in the second criterion. If this period exceeds a predetermined limit, the yarn 92 is removed from the measuring field 14, otherwise not. In another embodiment, the number of impermissible errors 93 detected since the last zero point adjustment and / or the last adjustment 222 can enter into the second criterion. If this number exceeds a predetermined limit, the yarn 92 is removed from the measuring field 14, otherwise not. Associations of these and other parameters and their entry into the second criterion are possible.

Of course, the present invention is not limited to the embodiments discussed above. In particular, the invention is not limited to the spinning station shown in Fig. 1, but is also suitable for other jobs of textile machines, for example. Of other spinning machines or dishwashers. With knowledge of the invention, the skilled person will be able to derive further variants, which also belong to the subject of the present invention.

LIST OF REFERENCE NUMBERS

[0038] <Tb> 1 <September> spinning unit <Tb> 11 <September> delivery device <Tb> 12 <September> spinner <Tb> 13 <September> Garnreinigermesskopf <Tb> 14 <September> measuring field <Tb> 15 <September> trigger mechanism <Tb> 16 <September> spooler <Tb> 17 <September> Garnchangiereinrichtung <Tb> 18 <September> winding roller <Tb> 19 <September> coil <Tb> 201 <September> of production <tb> 202 <SEP> Decision: Exit? <tb> 203 <SEP> Detection of Yarn Errors <tb> 204 <SEP> Check the detected error for its acceptability <tb> 205 <SEP> Characterization of the impermissible error with an error parameter <tb> 206 <SEP> Yarn interruption <tb> 207 <SEP> Decision: remove yarn from the measuring field? <tb> 211 <SEP> Leaving the yarn in the measurement area <tb> 213 <SEP> Rewind the yarn <tb> 214 <SEP> Cleaning the first yarn defect <tb> 221 <SEP> Remove the yarn from the patch panel <tb> 222 <SEP> Aligning and / or adjusting the measuring head <tb> 223 <SEP> rewinding the yarn <tb> 224 <SEP> Cleaning the second yarn fault <tb> 225 <SEP> Loading the yarn into the measurement field <Tb> 4 <September> Event Field <tb> 41 <SEP> abscissa: extension along the yarn longitudinal direction <tb> 42, 42 <SEP> Ordinate: Yarn parameter value <Tb> 43 <September> yarn package <tb> 44, 44 <SEP> Cleaning limit for thick places or thin places <Tb> 91 <September> fiber material <Tb> 92 <September> Yarn <Tb> 93 <September> yarn faults

Claims (16)

A method of operating a yarn cleaner including a yarn cleaner measuring head (13) having a measuring field (14) for receiving a yarn (92), wherein in which undue yarn defects (93) are detected (203) in the yarn (92) moved along the longitudinal direction thereof by the measuring field (14), characterized in that the yarn (92) is left in the measuring field (14) immediately after the detection (203) of at least one first impermissible yarn defect, and immediately after the detection (203) of at least one second illegal yarn defect the yarn (92) is removed from the measuring field (211). 14) is removed (221). 2. A method for operating a workstation (1) of a textile machine, for example. A spinning or winding machine, which is equipped with a Garnreinigermesskopf (13) with a measuring field (14) for receiving a yarn (92) in the yarn along its longitudinal direction through the measuring field (14) moved yarn (92) undetected yarn defects (93) are detected, characterized in that the yarn (92) is left in the measuring field (14) immediately after the detection (203) of at least one first impermissible yarn defect, and immediately after the detection (203) of at least one second illegal yarn defect the yarn (92) is removed from the measuring field (211). 14) is removed (221). A method according to any one of the preceding claims, wherein the measuring head (13) is adjusted to zero and / or adjusted (222) when the yarn (92) is cleared from the measuring field (14) after detection (203) of the at least one second improper yarn fault ) is removed (221). 4. The method according to any one of the preceding claims, wherein it is decided (204) on the basis of a predetermined first criterion, whether an impermissible Garnfehler or not. 5. Method according to claim 4, wherein a parameter value (AD) measured on the yarn (92) on the one hand and the extension (L) of the measured parameter value (AD) in the longitudinal direction of the yarn (92), on the other hand, enter the predetermined first criterion. A method according to any one of the preceding claims, wherein each improper yarn defect (93) is cleaned (214, 224) immediately after its detection (203) from the yarn (92). A method according to any one of the preceding claims, wherein upon detection (203) of an improper yarn defect (93), a decision is made (207) based on a predetermined second criterion as to whether the yarn (92) is removed from the measurement field (14) (221) or not (211). 8. The method of claim 7, wherein detected illegal yarn defects (93) each having at least one error parameter (L) are characterized (205) and the at least one error parameter (L) enters the predetermined second criterion. A method according to claim 8, wherein an error parameter (L) is an error length measured in the longitudinal direction of the yarn (92). 10. The method of claim 9, wherein according to the predetermined second criterion, the yarn (92) is removed from the measuring field (14) (221) when the error length (L) exceeds a predetermined limit. 11. yarn cleaner, containing a measuring head (13) comprising a sensor with a measuring field (14) for receiving a yarn (92), and an evaluation unit for evaluating an output signal of the sensor, wherein the evaluation comprises a detection (203) of impermissible yarn defects (93), characterized in that the evaluation unit is set up to cause the yarn (92) to remain in the measuring field (14) immediately after the detection (203) of at least one first illegal yarn defect (211) and immediately after the detection (203) of at least one second illegal yarn defect To cause removal of the yarn (92) from the measuring field (14) (221). 12. yarn cleaner according to claim 11, wherein the evaluation unit is adapted to the measuring head (13) to zero and / or adjust (222), when the yarn (92) after the detection (203) of the at least one second illegal yarn error the measuring field (14) is removed (221). 13. yarn cleaner according to claim 11 or 12, wherein the evaluation unit is adapted to decide based on a predetermined first criterion (204), whether an impermissible yarn fault is present or not. 14. yarn cleaner according to any one of claims 11-13, wherein the evaluation unit is adapted to immediately after the detection (203) of each improper yarn error (93) a cleaning (214, 224) of the yarn defect (93) from the yarn (92) to induce. 15. yarn cleaner according to one of claims 11-14, wherein the evaluation unit is adapted to (207) decide upon the detection (203) of an inadmissible Garnfehlers (93) on the basis of a predetermined second criterion, if the yarn (92) from the measuring field (14) is removed (221) or not (211). 16. The method according to claim 15, wherein the evaluation unit is configured to characterize detected impermissible yarn defects (93) with in each case at least one error parameter (L) (205), wherein the at least one error parameter (L) enters the predetermined second criterion.