WEAVING MACHINE WITH DEVICE AND METHOD FOR DETECTING VARIATIONS IN PILE-FORMING

Abstract

Disclosed is a weaving machine, including: a yarn tensioning system for keeping a pile-warp yarn under tension, including a local control unit, a drive motor Wand a drive roller; and a detection device for detecting abnormal variations in the pile-forming, including: a measuring system, for measuring, with the aid of the drive motor and the drive roller, pile-warp yarn consumption x.sub.m of the pile-warp yarn per cycle unit of one or more weft insertion cycles; a reference system, for determining for each cycle unit whether the pile-warp yarn is interlaced in a figure-forming manner and for determining the expected pile-warp yarn consumption x.sub.t; and a computing system, for comparing the measured with the expected pile-warp yarn consumption when the pile-warp yarn is interlaced in a figure-forming manner, and for detecting, on the basis of this comparison, abnormal variations.

In addition, disclosed is an associated method for detecting abnormal variations in pile-forming in a weaving machine.

Claims

1. Weaving machine, in which, in successive weft insertion cycles, at least one weft yarn is inserted between ground warp yarns so as to form together a ground fabric, and pile-warp yarns are interlaced according to a predefined weave pattern into the ground fabric in a figure-forming manner, or are incorporated in a non-figure-forming manner, comprising a yarn tensioning system for keeping at least one pile-warp yarn under tension and a detection device for detecting abnormal variations in pile-forming, wherein this detection device: comprises a measuring system, for measuring pile-warp yarn consumption x.sub.m of the at least one pile-warp yarn per cycle unit of one or more weft insertion cycles; comprises a reference system for determining on the basis of the predefined weave pattern, for each cycle unit, whether the at least one pile-warp yarn is interlaced in a figure-forming manner, and for determining the expected pile-warp yarn consumption x.sub.t for the at least one pile-warp yarn; and comprises a computing system, for comparing, for each cycle unit, the measured pile-warp yarn consumption x.sub.m with the expected pile-warp yarn consumption x.sub.t when the at least one pile-warp yarn, in this cycle unit, is interlaced in a figure-forming manner, and for, on the basis of this comparison, detecting abnormal variations; wherein the yarn tensioning system comprises a local control unit, comprises a drive motor Wand comprises a drive roller, wherein the drive motor is controllable with the local control unit for the driving of the drive roller in order to feed the at least one pile-warp yarn and keep it under tension, and wherein the measuring system is provided to measure the pile-warp yarn consumption x.sub.m with the aid of the drive motor and the local control unit, wherein the drive motor Wand the local control unit, for this purpose, form part of the measuring system.

2. Weaving machine according to claim 1, wherein this weaving machine comprises a central control unit for controlling the weaving machine in order to insert, in successive weft insertion cycles, at least one weft yarn between ground warp yarns so as together to form a ground fabric, and to interlace pile-warp yarns according to a predefined weave pattern into the ground fabric in a figure-forming manner, or to incorporate them in a non-figure-forming manner, and wherein this weaving machine comprises communication means for communicating between the central control unit and the local control unit whether the at least one pile-warp yarn is interlaced in a figure-forming manner, wherein the reference system makes use of these communication means to determine the expected pile-warp yarn consumption for the at least one pile-warp yarn.

3. Weaving machine according to claim 2, wherein the detection device comprises a storage system for storing abnormal variations and the time of occurrence of these abnormal variations.

4. Method for detecting abnormal variations in pile-forming in a weaving machine, in which, in successive weft insertion cycles, at least one weft yarn is inserted between ground warp yarns so as to form together a ground fabric, and pile-warp yarns are interlaced according to a predefined weave pattern into the ground fabric in a figure-forming manner, or are incorporated in a non-figure-forming manner, wherein this method, for each cycle unit of one or more weft insertion cycles, comprises the following steps: keeping at least one pile-warp yarn under tension; measuring pile-warp yarn consumption x.sub.m of the at least one pile-warp yarn; determining on the basis of the predefined weave pattern whether the at least one pile-warp yarn is interlaced in a figure-forming manner, and determining the expected pile-warp yarn consumption x.sub.t for the at least one pile-warp yarn; and comparing the measured pile-warp yarn consumption x.sub.m with the expected pile-warp yarn consumption x.sub.t, when the at least one pile-warp yarn is interlaced in a figure-forming manner, and detecting, on the basis of this comparison, abnormal variations; wherein the weaving machine is a weaving machine according to claim 1, in which the pile-warp yarn is kept under tension with the aid of the drive motor and the local control unit, and wherein the pile-warp yarn consumption is measured with the aid of the drive motor Wand the local control unit.

5. Method according to claim 4, wherein, in step d, the percentual variation Δx.sub.% of the measured pile-warp yarn consumption x.sub.m relative to the expected pile-warp yarn consumption x.sub.t is determined, and wherein, when this percentual variation Δx.sub.% exceeds an uppermost reference value r.sub.b, a signal is generated, and possibly the weaving machine is stopped in order to repair a fault.

6. Method according to claim 5, wherein, in step d, when the percentual variation Δx.sub.% remains below the uppermost reference value r.sub.b and exceeds a lowermost reference value r.sub.o, this percentual variation Δx.sub.% is written as a small variation into a buffer, and when, for a specific time, a plurality of small variations are written into the buffer, a signal is generated and the buffer is emptied.

7. Method according to claim 5, wherein the uppermost reference value r.sub.b, after a plurality of cycle units, is adapted as a function of the percentual variations Δx.sub.% determined during the cycle units.

8. Local control unit of a weaving machine according to claim 1, wherein this local control unit is configured to control the detection device of this weaving machine according to a method for detecting abnormal variations in pile-forming in a weaving machine, in which, in successive weft insertion cycles, at least one weft yarn is inserted between ground warp yarns so as to form together a ground fabric, and pile-warp yarns are interlaced according to a predefined weave pattern into the ground fabric in a figure-forming manner, or are incorporated in a non-figure-forming manner, wherein the method, for each cycle unit of one or more weft insertion cycles, comprises: keeping at least one pile-warp yarn under tension; measuring pile-warp yarn consumption x.sub.m of the at least one pile-warp yarn; determining on the basis of the predefined weave pattern whether the at least one pile-warp yarn is interlaced in a figure-forming manner, and determining the expected pile-warp yarn consumption x.sub.t for the at least one pile-warp yarn; and comparing the measured pile-warp yarn consumption x.sub.m with the expected pile-warp yarn consumption x.sub.t, when the at least one pile-warp yarn is interlaced in a figure-forming manner, and detecting, on the basis of this comparison, abnormal variations, wherein the pile-warp yarn is kept under tension with the aid of the drive motor and the local control unit, and wherein the pile-warp yarn consumption is measured with the aid of the drive motor and the local control unit.

9. Central control unit of a weaving machine according to claim 3, wherein this central control unit is configured to control the detection device of this weaving machine according to a method for detecting abnormal variations in pile-forming in a weaving machine, in which, in successive weft insertion cycles, at least one weft yarn is inserted between ground warp yarns so as to form together a ground fabric, and pile-warp yarns are interlaced according to a predefined weave pattern into the ground fabric in a figure-forming manner, or are incorporated in a non-figure-forming manner, wherein the method, for each cycle unit of one or more weft insertion cycles, comprises: keeping at least one pile-warp yarn under tension; measuring pile-warp yarn consumption x.sub.m of the at least one pile-warp yarn; determining on the basis of the predefined weave pattern whether the at least one pile-warp yarn is interlaced in a figure-forming manner, and determining the expected pile-warp yarn consumption x.sub.t for the at least one pile-warp yarn; and comparing the measured pile-warp yarn consumption x.sub.m with the expected pile-warp yarn consumption x.sub.t, when the at least one pile-warp yarn is interlaced in a figure-forming manner, and detecting, on the basis of this comparison, abnormal variations, wherein the pile-warp yarn is kept under tension with the aid of the drive motor and the local control unit, and wherein the pile-warp yarn consumption is measured with the aid of the drive motor and the local control unit.

10. Computer program product, comprising computer-readable code, which, when this code is executed on a local control unit according to claim 8, this produces the result that the local control unit controls the detection device of the weaving machine according to a method for detecting abnormal variations in pile-forming in a weaving machine, in which, in successive weft insertion cycles, at least one weft yarn is inserted between ground warp yarns so as to form together a ground fabric, and pile-warp yarns are interlaced according to a predefined weave pattern into the ground fabric in a figure-forming manner, or are incorporated in a non-figure-forming manner, wherein the method, for each cycle unit of one or more weft insertion cycles, comprises: keeping at least one pile-warp yarn under tension; measuring pile-warp yarn consumption x.sub.m of the at least one pile-warp yarn; determining on the basis of the predefined weave pattern whether the at least one pile-warp yarn is interlaced in a figure-forming manner, and determining the expected pile-warp yarn consumption x.sub.t for the at least one pile-warp yarn; and comparing the measured pile-warp yarn consumption x.sub.m with the expected pile-warp yarn consumption x.sub.t, when the at least one pile-warp yarn is interlaced in a figure-forming manner, and detecting, on the basis of this comparison, abnormal variations, wherein the pile-warp yarn is kept under tension with the aid of the drive motor and the local control unit, and wherein the pile-warp yarn consumption is measured with the aid of the drive motor and the local control unit.

11. Computer program product, comprising computer-readable code, which, when this code is executed on a central control unit according to claim 9, this produces the result that the central control unit controls the detection device of the weaving machine according to a method for detecting abnormal variations in pile-forming in a weaving machine, in which, in successive weft insertion cycles, at least one weft yarn is inserted between ground warp yarns so as to form together a ground fabric, and pile-warp yarns are interlaced according to a predefined weave pattern into the ground fabric in a figure-forming manner, or are incorporated in a non-figure-forming manner, wherein the method, for each cycle unit of one or more weft insertion cycles, comprises: keeping at least one pile-warp yarn under tension; measuring pile-warp yarn consumption x.sub.m of the at least one pile-warp yarn; determining on the basis of the predefined weave pattern whether the at least one pile-warp yarn is interlaced in a figure-forming manner, and determining the expected pile-warp yarn consumption x.sub.t for the at least one pile-warp yarn; and comparing the measured pile-warp yarn consumption x.sub.m with the expected pile-warp yarn consumption x.sub.t, when the at least one pile-warp yarn is interlaced in a figure-forming manner, and detecting, on the basis of this comparison, abnormal variations, wherein the pile-warp yarn is kept under tension with the aid of the drive motor and the local control unit, and wherein the pile-warp yarn consumption is measured with the aid of the drive motor and the local control unit.

12. Non-transient machine-readable storage medium, which stores a computer program product according to claim 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In this description, reference is made by means of reference numerals to the accompanying drawings, wherein in

[0067] FIG. 1 a weaving machine is represented schematically;

[0068] FIG. 2a a yarn-feeding module with an actuator is represented schematically;

[0069] FIG. 2b a part of a yarn-feeding module of the feed device from the weaving machine from FIG. 1 is depicted in perspective, wherein four actuators are portrayed for the feeding of four yarns;

[0070] FIG. 3 a graph of the pile-warp yarn tension and the pile-warp yarn consumption in pile-forming over time is represented;

[0071] FIG. 4 a graph of the pile-warp yarn tension and the pile-warp yarn consumption in non-figure-forming incorporating over time is represented;

[0072] FIG. 5 is represented a flow chart which illustrates a method according to the present disclosure.

DETAILED DESCRIPTION

[0073] In FIG. 1, a face-to-face weaving machine (1) is depicted. The disclosure is, however, also applicable to single-face weaving machines.

[0074] With weaving machines (1) of this type, it is possible to realize fabrics with cut pile and/or loop pile, wherein the piles can assume various pile heights and wherein the position and height of differing pile heights can be chosen. To this end, a defined weave pattern is formed in advance.

[0075] The depicted weaving machine (1) comprises a bobbin creel (17) as the yarn storage system, a feed device (16) for feeding pile-warp yarns (7) from the bobbin creel (17), via the beam stand (4), to a weaving device (5). Above the weaving device (5) is arranged a Jacquard (6) for controlling, on the basis of the predefined weave pattern, the heddles with which the pile-warp yarns (7) are positioned.

[0076] With the aid of the weaving machine (1), an upper and a lower pile fabric can thus be formed in the weaving device (5) in a known manner by inserting weft yarns, in successive weft insertion cycles, between ground warp yarns, so as to form together two ground fabrics, and to interlace pile-warp yarns (7) according to the predefined weave pattern into these ground fabrics in a figure-forming manner, or to incorporate them in a non-figure-forming manner.

[0077] The feed device (16) comprises a plurality of yarn-feeding modules (3) as depicted in FIG. 2b, which likewise serve as a yarn tensioning system, such as described in WO 2017/077454 A1. The depicted yarn-feeding module (3) comprises, for the driving of drive rollers (11), four motors (8), which are typically located in the housing (30). With the aid of these drive rollers (11), the pile-warp yarns (7) of bobbins (2) are unwound from the bobbin creel (17) and fed to the weaving device (5). The pile-warp yarns (7) are in this case, however, depicted for only two drive rollers. These pile-warp yarns (7) are pressed against the drive rollers (11) with the aid of tension rollers (12).

[0078] In FIG. 2a, a yarn-feeding module having a motor (8) is depicted schematically, wherein the housing (30) has been omitted and the motor (8) is visible.

[0079] The yarn-feeding modules (3) further comprise a local control unit (9), which on the one hand is connected to the motors (8), and on the other hand is connected to the central control unit (10) of the weaving machine (1).

[0080] In FIG. 5 is illustrated in a flow chart how, in such a weaving machine (1), abnormal variations in pile-forming can be detected.

[0081] For each cycle unit of one or more weft insertion cycles, it is examined by the central control unit (10), for each pile-warp yarn (7), whether this pile-warp yarn (7) is interlaced in a figure-forming manner or is incorporated in a non-figure-forming manner. When the pile-warp yarn (7) is interlaced in a figure-forming manner, this flow chart can be followed for this pile-warp yarn (7).

[0082] For this pile-warp yarn (7), there is here determined by the central control unit (10), on the basis of the pattern information of the predefined weave pattern, the expected pile-warp yarn consumption x.sub.t (19). This can be realized, for example, on the basis of measurement values in respect of test measurements or earlier measurements for comparable pile-forming during a cycle unit, or based on computations, comparable with existing computations for stock management. Preferably, a start is made with theoretically determined values, which then, over time, are modified on the basis of measurements.

[0083] The central control unit (10) forms with the herein stored pattern information a reference system for determining on the basis of the predefined weave pattern, for each cycle unit, whether the pile-warp yarn (7) is interlaced in a figure-forming manner, and for determining the expected pile-warp yarn consumption x.sub.t for this pile-warp yarn (7).

[0084] With the aid of the speed of the motor (8) and the diameter of the drive roller (11), the local control unit (9) is able to determine the pile-warp yarn consumption x.sub.m (18) of the pile-warp yarn (7) which is fed with this drive roller (11) to the weaving device (5). The central control unit (10) sends, for each cycle unit, a pulse to the local control unit (9) to start the measurement (18) of the pile-warp yarn consumption x.sub.m per cycle unit, this, for example, upon the beat-up of the reed (so that a weft insertion cycle is used as the cycle unit), or at the moment that the Jacquard (6) makes its selection (so that a Jacquard cycle is used as the cycle unit and thus the method is performed for every 2 weft insertion cycles).

[0085] The local control unit (9) and the motor (8) here form a measuring system for measuring the pile-warp yarn consumption x.sub.m of the pile-warp yarn (7) which is fed with the corresponding drive roller (11).

[0086] Even when the pile-warp yarn (7), during this cycle unit, is incorporated in a non-figure-forming manner, this pile-warp yarn consumption is able to be measured, in which case, however, no further detection according to the flow chart is carried out on this measurement. As further indicated, this measurement can then, together with the measurements of the pile-warp yarn consumption x.sub.m in pile-forming, be used, for example, for stock management.

[0087] The local control unit (9) can forward the pile-warp yarn consumption x.sub.m, measured per cycle unit, of a pile-forming pile-warp yarn (7) to the central control unit (10) of the weaving machine (1), this together with its ID, where the percentual variation Δx.sub.% of the measured pile-warp yarn consumption x.sub.m relative to the expected pile-warp yarn consumption x.sub.t is determined (20).

[0088] Another possibility is that the local control unit (9) gets sent the expected pile-warp yarn consumption x.sub.t from the central control unit (10) and itself determines this percentual variation Δx.sub.% (20).

[0089] The further detection can then be executed analogously, i.e. either by the local control unit (9) or by the central control unit (10). This local control unit (9) and/or this central control unit (10) then here form the computing system for comparing, for each cycle unit, the measured pile-warp yarn consumption x.sub.m with the expected pile-warp yarn consumption x.sub.t, and for, on the basis of this comparison, detecting abnormal variations.

[0090] It is firstly examined whether the percentual variation Δx.sub.% lies below a lowermost reference value r.sub.o (21).

[0091] Depending on the type of pile-forming, pile-warp yarn consumption can vary strongly. In FIGS. 3 and 4 can be seen measurements of pile-warp yarn tension (14) (in g) and pile-warp yarn consumption (15) (in mm), in the case of a maximum pile-forming (FIG. 3) and when this pile-warp yarn is incorporated in a non-figure-forming manner (FIG. 4). In the pile-forming, the average pile-warp yarn consumption is here 55 mm per weft insertion cycle, whilst this, is only 4.2 mm in the case of incorporation in a non-figure-forming manner. In the case of differing pile formations, the pile-warp yarn consumption (15) will lie somewhere between these two values.

[0092] In such measurements, variations of about 3% are observed between predicted consumption with a view to stock management, and effective consumption. As the lowermost reference value r.sub.o, 5% to 10%, for example, can initially be chosen, depending on the type of pile-forming. Over time, this reference value r.sub.o can be modified for example, as a function of the determined percentual variations Δx.sub.%, to about 4% to 8%, depending on the type of pile-forming.

[0093] If the percentual variation Δx.sub.% lies below the lowermost reference value r.sub.o, then there is no abnormal variation and the detection process can be repeated.

[0094] If the percentual variation Δx.sub.% lies above the lowermost reference value r.sub.o or coincides with this lowermost reference value r.sub.o, it is further examined whether this percentual variation Δx.sub.% lies above an uppermost reference value r.sub.b (22).

[0095] This uppermost reference value r.sub.b, just like the lowermost reference value r.sub.o, can be determined and/or modified on the basis of earlier measurements and in dependence on the type of pile-forming.

[0096] As the lowermost reference value r.sub.b, 10% to 25%, for example, can initially be chosen, depending on the type of pile-forming. Over time, this reference value r.sub.b, as a function of the determined percentual variations Δx.sub.%, can be modified, for example, to about 8% a 20%, depending on the type of pile-forming.

[0097] If the percentual variation Δx.sub.% lies above the uppermost reference value r.sub.o, then this indicates abnormal variation as a result of a major fault. A signal can then be generated (23), whereupon the fault can be further defined and repaired.

[0098] To this end, the yarn tensioning system (3) from FIG. 2b is provided, for example, with LEDs or lamps (13) as signalling means. Alternatively or additionally, it is also possible, for example, to signal abnormal variations via the Jacquard of the weaving machine, for example, or via a computer, or via smart wristbands, etc.

[0099] Further alternatively or additionally, the weaving machine can, for example, be stopped and hereupon, for example, be placed in a specific position in which a possible fault is easier to rectify. Thus all heddles, for example, can be let downwards and the heddle which has problems can be pulled upwards (or vice versa). Instead of simply pulling the heddle which has problems upwards (assuming that this heddle can no longer move), it can also be opted to pull upwards all heddles whereof the pile-warp yarns pass through the same dent as the pile-warp yarn which passes through the afflicted heddle.

[0100] Once the fault has been repaired and the weaving continued, the detection process can also be repeated.

[0101] If the percentual variation Δx.sub.% lies not above, but below the uppermost reference value r.sub.b, or coincides herewith, this indicates minor faults, which typically point to a sub-optimal weaving process. These minor faults will be regarded as normal or as abnormal, depending on the frequency of occurrence thereof. For the determination thereof, these can be saved in a buffer.

[0102] If the percentual variation Δx.sub.% lies not above, but below the uppermost reference value r.sub.b, or coincides herewith, then this buffer is firstly consulted (24).

[0103] It is examined whether this buffer is empty (25).

[0104] If this buffer is empty, then the fault, with a time indication thereof, is saved in the buffer (26).

[0105] If this buffer is not empty, then the time indication is determined by the last fault which was saved in the buffer (28).

[0106] If this time indication is less long ago than a defined reference time r.sub.t, then this is regarded as abnormal and a signal is generated (23), whereupon the fault can be further defined and repaired, as already described above. The weaving process, for example, can herein be optimized. The buffer is afterwards emptied.

[0107] If this time indication is longer ago than the defined reference time r.sub.t, then this is regarded as possibly normal and the fault, with a time indication thereof, is saved in the buffer (26).

[0108] Once a fault has been saved in the buffer (26), it is further examined whether the number of faults in this buffer lies above a defined reference value r.sub.a (27). If this is not the case, the detection process can straightaway be repeated.

[0109] If the number of faults in the buffer lies above this reference value r.sub.a, then this is regarded as abnormal and a signal is generated (23), whereupon the fault can be further defined and repaired, as already described above. The weaving process, for example, can herein be optimized. The buffer is afterwards emptied.

[0110] When the described detection process is executed in the central control unit (10), then this central control unit (10) can define the reference values on the basis of the pattern information and where necessary, after a certain time, modify these on the basis of the determined percentual variations Δx.sub.%.

[0111] When the described detection process is executed in the local control unit (9), then this local control unit (9) can receive reference values from the central control unit (10) and possibly, after a certain time, modify these on the basis of the determined percentual variations Δx.sub.%.

[0112] The determined percentual variations Δx.sub.% can also be used to, over time, modify the determination of the expected pile-warp yarn consumption x.sub.t.

[0113] The measurement values of the pile-warp yarn consumption x.sub.m measured per cycle unit can further also be stored and summated in order to determine the total pile-warp yarn consumption and thus do yarn stock management. These data can also be used to follow the consumption over the creel. With these data, a 3D overview can also, for example, be made of the consumption of the creel. There can also be signalled to an operator which bobbin has to be replaced, and the operator could signal that the bobbin has been replaced, whereby the consumption measurement can be restarted. For this, use can also be made, for example, of the aforementioned wristbands.