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EP-4739826-A1 - METHOD FOR OPERATING AN AIR-JET WEAVING MACHINE, AND AIR-JET WEAVING MACHINE

EP4739826A1EP 4739826 A1EP4739826 A1EP 4739826A1EP-4739826-A1

Abstract

In the case of a method for operating an air-jet weaving machine, a weaving shed (4) is formed by alternately raising and lowering warp threads (3) in accordance with a weaving pattern by shedding means. By means of air jets distributed over a weaving width, a weft thread (6) is inserted and cast on by means of a weaving reed. The air-jet weaving machine has a first drive, which is intended for driving the weaving reed and defines a weaving-machine angle (WMW), and at least one second drive, which is intended for driving the shedding means. The casting on of the weft thread (6) takes place at a weaving-machine angle (WMW) of 0°. A shed-closing angle (FSW), at which the weaving shed (4) is closed, is set with respect to the weaving-machine angle (WMW) by a control unit. For regular weaving operation, the shed-closing angle (FSW) is set to a weaving-machine angle (WMW) which lies after the casting on of the weft thread (6).

Inventors

  • CZURA, PETER
  • LEHMANN, MICHAEL

Assignees

  • Lindauer Dornier Gesellschaft Mit Beschränkter Haftung

Dates

Publication Date
20260513
Application Date
20240619

Claims (17)

  1. 1. Method, in particular a computer-implemented method, for operating an air-jet weaving machine (1), in which a shed (4) is formed by means of shedding means (2) depending on a weave pattern by alternately raising and lowering warp threads (3), a weft thread (6) is inserted by means of air nozzles (5) distributed over a weaving width (WB) and is beaten up by means of a reed (7), wherein the air-jet weaving machine (1) has a first drive (12) for driving the reed (7), which defines a weaving machine angle (WMW), and at least one second drive (13) for driving the shedding means (2), wherein the beating up of the weft thread (6) takes place at a weaving machine angle (WMW) of 0° and wherein a shed closing angle (FSW), at which the shed (4) is closed, is set by a control unit (14) in relation to the weaving machine angle (WMW), characterized in that the shed closing angle (FSW) for regular weaving operation is set to a weaving machine angle (WMW) which lies after the weft thread (6) has been beaten.
  2. 2. Method according to the preceding claim, characterized in that the shed closing angle (FSW) is set to a weaving machine angle (WMW) of up to 20° after the weft thread (6) has been struck, in particular is set to a weaving machine angle (WMW) between 10° and 20°.
  3. 3. Method according to one of the preceding claims, characterized in that the adjustment of the shed closing angle (FSW) to a weaving machine angle (WMW) after the beating of the weft thread (6) is limited to the regular weaving operation.
  4. 4. Method according to the preceding claim, characterized in that the setting of the shed closing angle (FSW) to a weaving machine angle (WMW) is applied after the weft thread (6) has been struck for the entire regular weaving operation.
  5. 5. Method according to one of the preceding claims, characterized in that the shed closing angle (FSW) for automatic and/or manual auxiliary movements of the first (12) and/or the at least one second drive (13) is set to a weaving machine angle (WMW) which lies before the beating of the weft thread (6).
  6. 6. Method according to one of the preceding claims, characterized in that during a start-up phase (15) of the air-jet weaving machine (1), the shed closing angle (FSW) is set to a weaving machine angle (WMW) which lies after the beating of the weft thread (6).
  7. 7. Method according to one of the preceding claims, characterized in that during a stop phase (16) of the air jet weaving machine (1) the shed closing angle (FSW) is set to a weaving machine angle (WMW) which lies before the beating of the weft thread (6).
  8. 8. Method according to one of the preceding claims, characterized in that the adjustment of the shed closing angle (FSW) is carried out while the air jet weaving machine (1) is running.
  9. 9. Method according to one of claims 6 - 8, characterized in that the shed closing angle (FSW) is shifted to the value to be set via intermediate values during a start phase (15) and/or a stop phase (16).
  10. 10. Method according to one of the preceding claims, characterized in that for warp threads (3) in an edge region (KB) of a fabric to be produced fabric (17) an earlier shedding angle (FSW) is set than for Warp threads (3) in a central region (MB) of the fabric to be produced (17).
  11. 11. Method according to one of the preceding claims, characterized in that an individual shed closing angle (FSW) is set for each weft insertion depending on a weave pattern.
  12. 12. Air jet loom (1) with shedding means (2) for opening and closing a shed depending on a weave pattern, with air jets (5) distributed over a weaving width (WB) for inserting a weft thread (6) and with a reed (7) for beating up an inserted weft thread (6), wherein the air jet loom (1) has a first drive (12) defining a weaving machine angle (WMW) for driving the reed (7) and at least one second drive (13) for driving the shedding means (2), and with a control unit (14) for controlling the drives (12, 13) and for setting a shed closing angle (FSW) in relation to the weaving machine angle (WMW), characterized in that the control unit (14) is designed to carry out the method according to one of the preceding claims.
  13. 13. Air jet weaving machine (1) according to the preceding claim, characterized in that the shedding means (2) comprise several heald shafts.
  14. 14. Air jet loom (1) according to the preceding claim, characterized in that the air jet loom (1) comprises an individual drive for each heald shaft.
  15. 15. Air jet loom (1) according to claim 12, characterized in that the shedding means (2) comprise a plurality of harness cords.
  16. 16. Air jet loom (1) according to the preceding claim, characterized in that the air jet loom (1) comprises an individual drive for each harness cord.
  17. 17. Computer program which, when executed by a control unit (14) of an air jet weaving machine (1), causes the control unit (14) to carry out the method according to one or more of claims 1 - 11.

Description

Method for operating an air-jet loom and air-jet loom The present invention relates to a method for operating an air jet weaving machine, in which a shed is formed by means of shedding means depending on a weave pattern by alternately raising and lowering warp threads, a weft thread is inserted by means of air jets distributed over a weaving width and is beaten up by means of a reed. The air jet weaving machine has a first drive for driving the reed, which defines a weaving machine angle, and at least one second drive for driving the shedding means. The weft thread is beaten up at a weaving machine angle of 0° and a shed closing angle at which the shed is closed is set by a control unit in relation to the weaving machine angle. A corresponding air jet weaving machine also has a control unit for controlling the drives and for setting a shed closing angle in relation to the weaving machine angle. Weaving machines are generally known in the state of the art. Weaving machines have a shedding device with shedding means for alternately raising and lowering warp threads, whereby a shed is alternately opened and closed. Weaving machines also have weft insertion means for inserting a weft thread into the opened shed. After weft insertion, the inserted weft thread is beaten up using a reed and the shed is then opened again for the next weft insertion. Specific weave patterns can also be produced by specifically raising and lowering the warp threads using the shedding means. From DE 10 2011 006 368 B3 a weaving machine with a first motor for Driving the weaving machine and with a second motor to drive a shedding device. The synchronicity of the two motors is achieved by Signals from a control unit. The first motor defines a weaving machine angle. The weft thread is always struck at a weaving machine angle of 0°. In such weaving machines with a separate drive to drive the shedding device, it is possible to set a shed closing angle, at which the shed is closed, to different times in relation to the weaving machine angle. When closing and then opening the shed, it can happen that individual warp threads of adjacent warp thread groups get caught on one another. No shed is formed between these warp threads. During the subsequent weft insertion, these clinging warp threads therefore cause problems such as weft breakage and warp breakage. To avoid this, the document suggests changing the shed closing angles during weaving so that several shed closing angles form an ascending or descending sequence. However, as is usual in the state of the art, all shed closing angles are well before the reed beat-up. The tendency of the warp threads to cling can be reduced in this way. In air jet weaving machines, a series of air jets are provided as weft insertion means distributed across the weaving width, which transport the weft thread through the weaving shed. The ejection position of the jets can influence the transport of the weft thread through the shed. It is therefore possible to set a working position for the air jets. EP 2 535 446 B1 discloses an air jet weaving machine in which the ejection positions of the air jets for different weaving conditions are defined in a database and then adjusted according to the weaving conditions. This is done by means of an actuator so that it is also possible to react to weaving conditions that change during the process. However, in air-jet looms, the warp threads can also be affected by the air jets. Especially with comparatively large warp density, capillary damage to the warp threads can occur through the air jets. The object of the present invention is to propose a method for operating an air-jet weaving machine and an air-jet weaving machine which at least reduce damage to the warp threads. The object is achieved by a method for operating an air-jet weaving machine and an air-jet weaving machine having the features of the independent patent claims. In a method for operating an air jet weaving machine, a shed is formed by means of shedding means depending on a weave pattern by alternately raising and lowering warp threads. A weft thread is inserted by means of air jets distributed over a weaving width and is beaten up by means of a reed. The air jet weaving machine has a first drive for driving the reed, which defines a weaving machine angle, and at least one second drive for driving the shedding means. The weft thread is beaten up at a weaving machine angle of 0° and a shed closing angle, at which the shed is closed, is set by a control unit in relation to the weaving machine angle. It is proposed that the shed closing angle for regular weaving operation be set to a weaving machine angle that is after the weft thread has been struck. In other words, the shed closing angle is set at least for regular operation so that the shed is still open when the reed is struck and only closes after the reed has been struck. The applicant has found that with a shed closing angle after the reed has been s