EP1685054A1

EP1685054A1 - Yarn cleaner

Info

Publication number: EP1685054A1
Application number: EP04765945A
Authority: EP
Inventors: Iris Biermann; Olav Birlem; Hans Grecksch; Christoph Haase; Gerhard Rienas
Original assignee: Saurer GmbH and Co KG
Current assignee: Oerlikon Textile GmbH and Co KG
Priority date: 2003-11-10
Filing date: 2004-10-13
Publication date: 2006-08-02
Anticipated expiration: 2024-10-13
Also published as: CN100415622C; US7424800B2; WO2005047155A1; DE10352429A1; EP1685054B1; US20070119144A1; CN1867508A; DE502004007304D1

Abstract

The yarn cleaner (5) is designed for cleaning out defects from an effect yarn (1), which is formed from an alternating stringing together of webs and of effects comprised of given thickenings. The yarn cleaner has a measuring head (6) in which at least one yarn parameter is measured, whereby cleaning limits are determined for the yarn parameter, and the presence of a defect in the yarn is signaled when these limits are surpassed. The measured values of the yarn parameter are compared with the cleaning limits and intolerable defects are cut out from the yarn. The cleaning limits are each dependent on whether the values are measured in the web or in the effect. The yarn cleaner (5) is suited for keeping the desired diameter quality of effect yarn on winding and spinning winding machines.

Description

Description:

yarn clearer

The invention relates to a yarn cleaner according to the preamble of claim 1.

In the production of yarn is usually the highest possible uniformity of the yarn in close tolerances and a yarn without visible defects, as are intolerable thick or thin spots in the yarn, sought. To achieve this, so-called yarn cleaners are used, which monitor, for example, the diameter of the yarn continuously with a non-contact measuring head. If an intolerable error is detected due to the exceeding of limit values designated as cleaning limits, the error is cut out of the yarn, the yarn ends are reconnected and the production process is continued as known, for example, from DE 10062479 A1.

In a conventional yarn monitoring a single reference diameter is determined and chosen for cleaning limits. For example, from the reference "Electronic yarn monitoring system Corolab for rotor spinning machines Autocoro", man-made fibers / textile industry, 40. / 92. Vintage, April 1990, it is known for determining a reference diameter to make a diameter average determination of the yarn at the beginning of the measurement at a spinning station on the first yarn meter. This so-called reference diameter is the reference diameter for all further evaluations. Measured actual diameters of the yarn are usually given as a percentage of the reference diameter. It is an object of the invention to provide a cleaner whose application is increased.

This object is achieved with a yarn cleaner with the features of claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

The yarn cleaner according to the invention makes it possible to detect diameter-related yarn defects even with effect yarn. The variability of the yarn parameter, which is caused solely by the change between webs and effects, does not result in unnecessary cutting operations which would reduce productivity and create undesirable joints.

If different cleaning limits are specified for the bridge and the effect, the error determination can be carried out almost as accurately as with an effect-free yarn (claim 2).

The known cleaning functions are largely applicable, whereby a satisfactory evaluation of the produced effect yarn is possible (claim 3).

If either defects in the land areas or defects in the effect areas can be tolerated in a fancy yarn, the yarn cleaner according to claim 4 can be set up. The selection of only the effects may be due to the fact that the satisfactory bridge training is assumed, but the effect training is not reliable enough. Alternatively, if it can be assumed that deviations in the effect training are not significant, it may be sufficient if only the longer bridge segments are analogous to a regular one Yarn to be cleaned. With the restriction to one alternative, the amount of computation required and the number of times of cutting can be reduced.

The diameter of the effect yarn is primarily used as a yarn parameter, the cleaning limits being different depending on the respective measuring point, ie web or effect.

The web diameter, also referred to as web thickness, can be determined with a yarn cleaner according to claim 8 largely uninfluenced by the effects and thus close to reality. This also has a positive effect on the accuracy of the effect detection.

With a yarn cleaner according to claim 9, a relatively simple, but sufficiently accurate effect boundary determination is possible.

With the development of the yarn cleaner according to claim 10 counteracts a set too low average for the effects. On the one hand, a low average could lead to unwanted cuts if the effect is partially intentionally strong. On the other hand, there would be insufficient differentiation of the cleaning boundaries between effect and ridge.

With a yarn cleaner according to claim 9 and 11, the boundary between web and effect can be determined with sufficient accuracy for the cleaning of the effect yarn.

If lower demands are placed on the cleaning of a fancy yarn with regard to the adherence to the diameter a Garnreiniger set up according to claim 12 be sufficient. With such a yarn cleaner, the effort required for the cleaning of the effect yarn can be reduced. On the other hand, it is nevertheless ensured that unnecessary cuts are not made, which are caused by effect-related diameter fluctuations. Such a cleaner is particularly sufficient if the effects are not particularly pronounced.

The invention is explained in more detail with reference to an embodiment. Show it:

1 is a simplified schematic representation of a workstation of a spinning winder,

2 shows an effect yarn, which is represented by the juxtaposition of measured values of the yarn diameter,

Fig. 3 is a schematic representation of an effect area with adjacent web parts.

In the spinning station shown in Fig. 1, the effect yarn 1 is withdrawn through the take-off tube 2 from the spinning device 3 and wound onto the cheese 4. The effect yarn 1 passes between the spinning device 3 and cheese 4 a yarn cleaner 5, which includes a measuring head 6 and a processor 8, and then a guide eye 9. The yarn cleaner 5 is associated with a thread monitor 7. The drive drum 10 drives the cheese 4 during the winding by means of frictional engagement. A motor 11 gives the drive drum 10 the rotational movement. The yarn cleaner 5 is used to monitor the quality of the current fancy yarn 1. Der Garnreiniger 5 is connected to other facilities for control, data storage or evaluation and the control of other elements of the spinning unit or the spinning machine by means of the line 12. The components of the yarn cleaner 5 may be integrated in a common housing.

Alternatively, the effect yarn can also be withdrawn from a delivery bobbin instead of a spinning device.

Fig. 2 shows the representation of the effect yarn 1 as a juxtaposition of measured values. Although the regions of the effects 13 and of the webs 14 are recognizable, the beginning and end of the effects 13 and the effect thickness or the effect diameter D _E and the web thickness or the web diameter D _S _{/ are} not clear and therefore not sufficiently recognizable.

The yarn cleaner 5 registers the yarn diameter D at a distance of 2 mm. One cycle represents a measuring length of 2 mm effect yarn 1. To determine the web diameter D _S τ used for the cleaning, the cleaner 5 first forms an arithmetic mean of the yarn diameter from a predetermined length of effect yarn 1 as a reference diameter at the start of the measurement, subtracts the reference diameter from the measured individual values of the yarn diameter and forms the mean value of the web diameter D _sτ as an arithmetic mean of all negative difference values that have been measured adjacent to other negative difference values.

The determination of the effect diameter D _E and the boundaries between effects 13 and webs 14 will be explained with reference to FIG. In the illustration of FIG. 3 is the Yarn diameter D in percent over the yarn length L _{G shown} as a curve 15. The curve 15 represents in the illustration of Fig. 3 from the left beginning to the point 16 the

Stegdurchmesser D _sτ - From the point 16, the curve 15 increases and passes at point 17, the value of the limit diameter D _GR . At point 18, the predetermined yarn length L _v has passed since reaching the point 17. After a diameter increase of 15% is registered at point 17 and the exceeding of the limit diameter D _GR over the predetermined length L _v, for example, lasts six cycles or 12 mm long, the point 17 is defined as the beginning of the effect 13. The curve 15 falls below the limit diameter D _GR at the point 19. The undershooting stops until the point 20 and thus over the predetermined yarn length L _v . Thus, the point 19 is defined as the end of the effect 13. The area between point 17 and point 19 is defined as effect 13. The section of the effect yarn 1 following point 19 or the end of the effect 13 is defined as a web 14 until a start of an effect 13 is determined again.

From the four largest diameters 21 within the effect 13 an arithmetic mean is formed. Thus, the indication of the effective diameter D _{E is} largely independent of natural Duchmesserschwankungen in the effect area. The effect diameter D _E is defined as this arithmetic mean.

The effect diameter D _E is assigned a predetermined tolerance range with a cleaning limit RG _E0 as the upper limit value and with a cleaning limit RG _EÜ as the lower limit value. Accordingly, the web diameter D _{sτ is} a predetermined tolerance range with a cleaning limit RG _S τo as upper Limit value and with a cleaning limit RG _ST u assigned as a lower limit.

The yarn cleaner 5 continuously determines whether the diameter values of the effect yarn 1 detected by the measuring head 6 originate from a region which is defined as a web 14 or as an effect 13. If the diameter values of the effect yarn 1 originate from a region which is defined as a web 14, these diameter values become with the limit values assigned to the web diameter D _sτ , the cleaning limit RG _S τo and the

Cleaning limit RG _ST u compared. If the diameter values of the effect yarn 1 originate from a region which is defined as effect 13, these diameter values are compared with the limit values associated with the effect diameter D _E , the cleaning limit RG _E0 and the cleaning limit RG _E u.

Alternatively, the yarn cleaner 5 may be arranged so that either only defects in land areas or only defects in effect areas are cleaned out.

Alternatively, the cleaning limits of the yarn cleaner 5 may be set so that they lie outside the fluctuation width B _s of the effect 13 and the web 14 identified in FIG. 3. The fluctuation width B _s denotes the distance between the diameter of the effect 13 and the diameter of the web 14 and. In this case, the continuously measured diameter values of the effect yarn 1 are compared with only the cleaning limit RG _E0 and the cleaning limit RG _S τu, for example, to detect overshoot. The cleaning limit RG _E0 denotes the upper tolerable limit of the effect diameter D _E and the

Cleaning limit RG _S τu the lower tolerable limit of the web diameter D _S τ In a first embodiment of the yarn cleaner 5 is set up so that the exceeding of these limits or cleaning limits registered as an untolerable error and this is cut out.

In a second embodiment, the yarn cleaner 5 is alternatively set up so that when these limit values or cleaning limits are exceeded, it is detected over which yarn length the exceeding continues. By means of a known two-dimensional classifying matrix, also called a cleaner matrix, it is decided whether there is an untolerable error, and in this way the error lengths are included in the determination of the cleaning limits. A classifying matrix is divided into length ranges in one dimension and into diameter ranges in the other dimension and forms a class by combining a length range with a diameter range. The cleaning of yarn according to classes is known, for example, from the reference "Complete system for quality assurance in winding", Melliand - reprint October 1992, for a long time.

Further embodiments of the yarn cleaner in the invention are possible and not limited to the illustrated embodiment.

Claims

Claims:

1. Yarn cleaner for cleaning out defects from a yarn, in the measuring head of which at least one yarn parameter is measured, cleaning limits being determined for the yarn parameter, the exceeding of which signals the presence of an error in the yarn, for which purpose the measured values of the yarn parameter are compared with the cleaning limits and whereby intolerable defects are cut out of the yarn, characterized in that the yarn cleaner is set up for cleaning out fancy yarn (1), which is formed from an alternating series of webs (14) and effects (13) consisting of predetermined thickenings, that at least a value of the yarn parameter for webs (14) and for effects (13) of the fancy yarn (1) is predetermined and that the cleaning limits of the yarn cleaner (5) are set such that they are outside the predetermined value of the web parameter and outside the predetermined value of the effect parameter lie.

2. Yarn cleaner according to claim 1, characterized in that the cleaning limits each depend on whether the values in the web (14) or in the effect (13) are measured.

3. Yarn cleaner according to claim 1 or 2, characterized in that the yarn cleaner (5) is set up to implement known yarn cleaning functions in such a way that at least one of the following errors is detected: short thick spot, long thick spot, short thin section, long thin section, periodically recurring errors.

4. Yarn cleaner according to one of claims 1 to 3, characterized in that the yarn cleaner (5) is set up in such a way that either only defects in web areas or only defects in effect areas are cleaned out.

5. Yarn cleaner according to one of claims 1 to 3, characterized in that the yarn parameter is the diameter of the fancy yarn (1), that the cleaning limits of the yarn cleaner (5) are matched to at least one diameter value for the effect thickness and to at least one diameter value for the web thickness and that the yarn cleaner (5) compares the determined diameter values with the respective cleaning limits, which depend on whether the measurement takes place in a web area or in an effect area of the fancy yarn (1).

6. Yarn cleaner according to claim 5, characterized in that the yarn cleaner (5) is set up in such a way that it determines the average diameter values of the webs (14) and the average diameter values of the effects (13) over a predetermined yarn length, and that the average diameter values are determined at least at the beginning of the measurement.

7. Yarn cleaner according to one of claims 5 or 6, characterized in that the error lengths are included in the determination of the cleaning limits.

8. Yarn cleaner according to one of claims 5 to 7, characterized in that it for determining the average of the Web diameter D _S τ first forms an arithmetic mean value of the yarn diameter from a predetermined length of fancy yarn (1) as the reference diameter, subtracts the reference diameter from the individual values of the yarn diameter and forms the mean value of the web diameter D _S τ as an arithmetic mean value from all negative difference values that are adjacent to other negative difference values have been measured.

9. Yarn cleaner according to one of claims 5 to 8, characterized in that the yarn cleaner (5) is set up in such a way that it determines the effect area in that the beginning of the effect (13) by fulfilling a first criterion and that the end of the effect is defined by fulfilling a second criterion, a definable number of the largest diameters is determined between the start and end of the effect (13), an arithmetic mean is formed from the ascertained diameters, which is determined as the diameter of the effect (13), and the range of the Fancy yarn (1) outside the effect (13) is defined as a web area.

10. Yarn cleaner according to claim 9, characterized in that the diameter D _{E of} the effect (13) is formed as the mean diameter from the four largest diameters between the beginning and end of the effect (13).

11. Yarn cleaner according to one of claims 9 or 10, characterized in that the first criterion is the exceeding of a limit diameter D _GR , which is larger by a defined amount than the mean value of the web diameter D _S τ and that the exceeding over a predetermined yarn length L _v ι lasts and that second The criterion of falling below the limit diameter D _GR applies and the drop below the predetermined yarn length L _v2 continues.

12. Yarn cleaner according to one of claims 1 to 11, characterized in that the yarn cleaner (5) is designed such that its cleaning limits are set so that they lie outside the fluctuation range B _s of effect (13) and web (14).