EP2741988A2

EP2741988A2 - Method and weaving machine having an apparatus for monitoring thread overtension

Info

Publication number: EP2741988A2
Application number: EP12745803.2A
Authority: EP
Inventors: Adnan Wahhoud; Harald Arnold
Original assignee: Lindauer Dornier GmbH
Current assignee: Lindauer Dornier GmbH
Priority date: 2011-08-08
Filing date: 2012-07-19
Publication date: 2014-06-18
Anticipated expiration: 2032-07-19
Also published as: JP5829335B2; CN103717520A; EP2741988B1; DE102011080629A1; JP2014524993A; KR101557248B1; CN103717520B; KR20140030305A; WO2013020782A3; WO2013020782A2

Abstract

The invention relates to a method for monitoring thread overtension in a weaving machine having mechanical weft insertion elements (1) and also to a weaving machine having an apparatus for carrying out the method. In this case, threads (2) which extend in a warp direction (20) are supplied from a thread store to shedding elements (3) via a thread stop motion (4), wherein, when the tension in one of the threads (2) drops below a particular level, a signal is generated at the weaving machine by the thread stop motion (4). The invention is characterized in that at least one group of threads (2.1, 2.2) extending in the warp direction (20) is guided between the thread store and the shedding elements (3) over an elastically deflectable thread deflecting element (5) such that, when a particular tension in one of the threads (2.1) in this group (2.1, 2.2) is exceeded, the thread deflecting element (5) is deflected such that, as a result of this deflection, the tension in at least one other thread (2.2) in this group (2.1, 2.2) is reduced to such an extent that the thread stop motion (4) generates a signal.

Description

Method and loom with a device for monitoring a thread overvoltage

Technical area

The present invention relates to a method and a weaving machine with a device for monitoring a yarn overstress on the loom.

State of the art

In weaving machines, devices for monitoring the tension and the course of threads running in the warp direction are known in the prior art.

Such a device and a method executable therewith are shown, for example, in EP 262724 B1. Each warp thread is guided over its own warp control lamella, which closes an electrical contact with decreasing thread tension in the respective warp thread within the loom. By closing the

Contact is triggered further operations on the loom, for example, a machine stop.

Devices of this type are generally between a thread supply for the warp threads - e.g. a warp beam - and means for forming a shed - e.g. Shafts - arranged in the course of the thread. They are used to recognize torn or sticking, so-called clinging warp threads. A monitoring of voltage peaks in one of the threads extending in the warp direction is thus not possible in the prior art. such

Voltage overshoots can occur, for example, as a result of a disturbed thread course in the shed in the weft insertion area of the weaving machine.

The eligible weft insertion area of the loom is called

Designated front compartment. The front compartment is formed of at least two sets of warp threads extending from the shed forming elements through the reed to the binding point of the fabric. These two groups of warp threads are alternately moved in such a way in a top compartment and in a lower compartment, that in the resulting space weft threads can be entered.

To compensate for the voltage fluctuations that arise due to the movement of the compartment elements in the warp threads, it is common for all warp threads on the Weaving machine over an elastically deflectable Fadenumlenkelement - for example, a spring-loaded bowing tree or a spring plate - to lead.

The yarns of the front compartment running in the warp direction can, under certain circumstances, be introduced from the weft insertion elements in the weft insertion

unwanted manner and be diverted out of its normal course out. This can lead to the tearing off of the respective threads and possibly to disturbances of the movement of the weft insertion elements. This process can be triggered, for example, by the tension in one of the warp threads first dropping to such an extent that no signal from the warp guard is thereby released, so that the weaving machine continues to run. Due to the sinking tension, this thread sags

Upper compartment, which can thus enter the trajectory of the weft insertion elements. If this thread is caught by one of the weft insertion elements, it is deflected around this or deflected by this in the weft direction.

If this additional deflection or deflection is not detected in time, serious disturbances of the weft insertion can be caused. At least, however, causes a deflection of warp threads of the upper compartment by a weft insertion element into the lower compartment - or vice versa - a

Binding errors.

The present invention aims to automatically detect such operations on the loom.

Description of the invention

This object is achieved by a method and a weaving machine with a device according to the independent claims.

The method according to the invention serves to monitor a yarn overstress in a weaving machine with mechanical weft insertion elements. By the weft insertion elements - e.g. Gripper or projectile - is in a known manner a weft in the weft direction in a shed of the

Weaving machine registered. The threads running in the warp direction are withdrawn from a thread supply - eg a warp beam -, passed over a thread monitor and then fed to elements for shedding. Due to the movement of the compartmentalized elements, the warp threads form a shed with a top compartment and a bottom compartment. When falling below a certain

Tension in one of the warp threads is controlled by the thread monitor - e.g. one

Warp stopper according to the prior art - generates a signal. This signal can be used, for example, to stop the machine immediately.

The method according to the invention is characterized in that at least one group of yarns extending in the warp direction between the yarn supply and the shed forming elements is guided over an elastically deflectable Fadenumlenkelement that when exceeding a certain voltage in one of the threads of this group by an elastic deflection of the Fadenumlenkelements the voltage is reduced in at least one other thread of this group such that the thread monitor generates a signal.

When the thread tension in only one of the threads of the group increases, the deflecting element is deflected more elastically. As a result, however, the sinks

Stress in all other threads of the group of warp threads. When a certain tension in one thread of the group is exceeded, the deflection reaches a level that a signal is triggered by the decreasing tension in one or more other threads of the group on the thread monitor.

The increase in tension in the one warp thread of a group can occur, for example, as a result of this thread being caught by, deflected by, or deflected about by one of the weft insertion elements. By the signal that triggers the warp stop, the weaving machine can be stopped immediately before this process to further weft insertion disorders or

Tissue defects leads.

It is advantageous for the method if a basic thread tension is present in all threads of the relevant group of warp threads. Due to this basic warp tension, it is prevented that despite changing thread tensions due to the shed formation in the normal, undisturbed weaving operation already signals on

Thread monitor be generated. As a rule, this base thread tension already leads to an elastic deflection of the thread deflecting element in the direction in which the threads are deflected, so that an additional elastic deflection of the thread is induced by an additional increase in tension in one of these threads Thread deflecting element is caused in this direction. The basic thread tension of the entire group of warp threads is advantageously produced in a known manner by electromechanical means for warp tension control of the weaving machine. Depending on how large this warp tension is, the Fadenumlenkelement over which the group of warp threads is guided, more or less strongly elastically deflected already by the fluctuating ground tension or Grundkettspannung. As a result of this deflection, in addition to the function according to the invention, even in the entire group of warp threads a compensation of the voltage changes which are produced by the shed forming elements moving up and down can be achieved.

An advantageous embodiment of the invention is characterized in that the number of guided over the Fadenumlenkelement group of warp threads are tuned in a certain way to the elasticity of the deflected threads and the elasticity and the formation of the Fadenumlenkelements. The vote takes place in such a way that starting from an undisturbed position of the threads of this Kettfad engruppe in a top compartment or in a sub-compartment disturbing the thread path by an additional deflection of one of these threads to the weft insertion element to such a voltage increase in this additional deflected thread leads that through the following

Voltage reduction in at least one other thread of the group in question by the thread monitor a signal is generated.

With additional deflection is meant a threadline, in which a warp thread, which should extend straight above or below the weft insertion element from the associated shedding element to a binding point of the fabric, instead extends from the shedding element to a lower or upper edge of the weft insertion element and from there to the binding point. A warp thread in the upper shed is deflected so far from the weft insertion element that he gets here in places in the lower shed, while a warp thread in the lower shed at the additional deflection by the weft insertion points in places reaches the upper shed.

The increase in tension in the additionally deflected by the disturbance thread leads to an additional elastic deflection of the Fadenumlenkelements over which this thread is guided. This extra deflection reduces the deflection or the size of the deflection angle of the threads on this Fadenumlenkelement. This reduces the tension in the threads of the thread group.

The coordination of the number of threads on the elasticity of the warp threads used and on the Fadenumlenkelement done in a manner that the Kettfadenwächter generates a signal at the latest when the increase in voltage in one of the warp threads of the group has reached an order of magnitude, as in an additional Deflection occurs around the weft insertion element in the manner described.

For very elastic warp threads is obtained by an additional deflection of the type described only a small increase in voltage in additionally deflected thread. Therefore, there is only a small additional deflection of the

Fadenumlenkelements, that yes already by the tension of all other warp threads of the respective group and by existing in these threads

Base voltage is deflected. Thus, in the remaining warps of the respective group by the additional deflection of the Fadenumlenkelements the voltage drops far enough to trigger a signal on Kettfadenwächter, the number of warp threads of the group of elastic warp threads may not be too large.

An advantageous embodiment of the method according to the invention is therefore characterized in that a group running in the warp direction threads, which are guided over the elastically deflectable Fadenumlenkelement, consists of 2 - 20 threads.

For very stiff, less elastic warp threads results in a small increase in tension in one of the threads, a large additional deflection of Fadenumlenkelements and therefore a strong lowering of the tension in the other threads of this group. The number of threads in this group can therefore be greater than with very elastic threads.

The method according to the invention can be used particularly advantageously in the case of very stiff, robust warp threads which, upon collision with a weft insertion element, cause considerable disturbances. This applies above all to warp threads of ribbon or wire-like material, but also very robust threads of aramid or carbon fibers. Because of the above-described relationships between the elasticity of the warp threads and the number of threads in a group, which are guided over a common Fadenumlenkelement, results in very stiff, low-stretch warp threads and a smaller number of individual Fadenumlenkelementen for a given total number of warp threads on a loom ,

The method described for the monitoring of thread overstress in warp threads can of course also be used for the monitoring of leno or ground threads in the manufacture of fabrics with leno weave. In addition, it is applicable to the monitoring of warp yarns used for edge formation - e.g. Threads of a trap or a leno selvedge.

Thread overvoltages in one of the yarns running in the warp direction can, of course, also be due to causes other than the additional deflection by a weft insertion element. This can be for example

Thread overstresses due to strand breaks in one of the

Shedding elements or due to lamella fractures in the reed of the

Weaving machine. Even such surges can with the

Inventive methods are detected and monitored. In a weaving machine with mechanical weft insertion elements with a device according to the present invention, a thread overstress in threads can be monitored, which extend substantially in the warp direction. The device comprises means for storing the threads - e.g. Warp threads, as well as elements for shedding and at least one thread monitor, which is arranged in the course of the threads between the device for storing the threads and the shed forming elements and with which falls below a certain voltage in at least one of the thread monitor monitorable threads a signal can be generated.

In addition, a Fadenumlenkelement is present, which is elastically deflectable and which is arranged between the means for storing the threads and the shed forming elements in the thread pattern of a group of threads, in

Warp direction.

The device is further characterized in that the elastic

Deflection, as well as the formation of Fadenumlenkelements in a certain way and tuned to the number and the elasticity of a group to be deflected in the warp direction extending threads. This vote is done, for example, by the fact that the spring constant of a designed as Fadenumlenkelement elastically deformable spiral spring is chosen constructively suitable. However, also conceivable brush-like arrangements in which a rigid

Deflection mounted rotatably and biased by a tension or compression spring with a defined spring constant. The elastic deflectability and the

Forming the Fadenumlenkelements in the examples described is carried out according to the invention, taking into account the number and elasticity of an im

Web process the loom existing group to be deflected threads such that starting from an undisturbed position of this group of warp threads in the upper compartment or in the lower part of the loom by an additional

Deflection of one of the threads of this group to the weft insertion such a voltage increase is generated in this additional deflected thread that is generated by the thread monitor a signal via the additional deflection caused by the Fadenumlenkelements and the subsequent reduction in voltage in at least one other thread.

Due to the additional deflection of the Fadenumlenkelements the deflection or the size of the deflection angle of the threads is reduced at this Fadenumlenkelement. This results in a subsequent voltage reduction in the threads of this thread group.

As already mentioned in the method, it is advantageous if a Grundkettspannung is present on the loom. Therefore, it is advantageous to provide electromechanical means for warp tension control on the weaving machine according to the invention, which are already known from the prior art.

So that the threads, which are guided in the warp direction over the Fadenumlenkelement, can not escape in the weft direction, it is advantageous if the

Thread deflecting at least one thread guide element, with the running in the warp direction threads in the weft direction can be guided. As already explained in the method, it is advantageous if only a relatively small number of warp threads to be monitored together via a

Thread deflection is performed. Thus, a large number of warp threads can be monitored, it is therefore advantageous if several Fadenumlenkelemente are arranged distributed over the width of the loom for several groups of yarns running in the warp direction.

A particularly economical embodiment of the Fadenumlenkelemente is achievable that they are formed as a bending springs of contiguous sub-segments of a single spring plate.

Brief description of the drawings

Figure 1 Schematic representation of an embodiment of

Device according to the invention.

Detailed description of an advantageous embodiment of the invention

Figure 1 shows an example of a weaving machine according to the invention with a device for monitoring a yarn overstress. The weaving machine has a gripper 1 for the entry of weft threads in a shed. Frequently, however, such weaving machines are also equipped with two grippers 1, one of which brings a weft thread to the center of the fabric 9, while the other pulls the weft thread from the center to the outside. From a warp beam, not shown, for example, above the

Weaving machine is arranged, warp threads 2 are removable, which extend in the weaving machine substantially in the warp direction 20. As shedding elements 3 healds 3.1 are present in the present example, not shown above

Shelf drives - eg a dobby with shafts - are alternately moved up and down. FIG. 1 shows the weaving machine with warp threads 2, which are guided by the healds 3.1 in such a way that the warp threads 2 are brought alternately into a top shed 21 and into a bottom shed 22 by the movement of the shed forming elements 3. As a shingles drive can of course also a jacquard machine with a harness that moves the healds 3.1 shingles.

The loom further comprises a warp stop 4, which is arranged in the course of the warp threads 2 between the warp beam and shed forming elements 3. The warp monitor 4 is preferred with Kettwächterlamellen 4.1. equipped, each of which is associated with one of the warp threads 2. But there are others too

Thread monitor principles - e.g. optical systems can be used with which a sinking thread tension or caused thereby changed thread pattern of the threads 2 can be detected.

When pulling off the warp threads 2 from the warp beam, a base-chain tension in the warp threads 2 is set by means for controlling the warp tension. Such warp tension controls are known in the art and are therefore not shown here. As a result of the base-chain voltage, a Kettwächterlamelle 4.1. above a contact rail 4.2. held. At the

Fall below a certain thread tension or breakage of a warp 2 falls Kettwächterlamelle 4.1 on the contact rail 4.2 and closes an electrical contact. This generates a signal on the weaving machine.

The loom according to Figure 1 further comprises a spring plate 7, which consists of several sub-segments 7.1. Each subsegment 7.1 forms

Fadenumlenkelement 5. The spring plate-like sub-segments 7.1 are elastically deformable, so that the Fadenumlenkelement 5 a deflection in the

Direction results in which the warp threads 2 are deflected by the Fadenumlenkelement 5. Each Fadenumlenkelement 5 is arranged in the thread pattern of a group of warp threads 2.1, 2.2 between the warp beam and the shedding elements 3.

In normal weaving operation voltage fluctuations in the warp threads 2 due to the changing up and down movement of the shedding elements 3. These are compensated by the elastic deflectability of Fadenumlenkelemente 5 so far that no signal is triggered by the warp monitor 4 in the normal weaving operation. The highest thread tension occurs when all warp threads 2 are in the upper shed 21 or lower shed 22. The lowest

Thread tension occurs when the healds 3.1 are all at the same height, that is in the closed compartment of the loom. The position of the Fadenumlenkelemente 5 and 4 of the warp monitor in the yarn path of the warp threads 2 is advantageous chosen so that the function described is guaranteed. This corresponds to the function and the procedure of the person skilled in a known in the art string tree device.

The weaving machine according to FIG. 1 furthermore has a reed 8, with which weft threads, which are entered by the gripper 1 into the shed, are struck against the binding point 24 of the fabric 9.

The spring stiffness of the spring plate 7 with the sub-segments 7.1 is matched to the number and the elasticity or elasticity of the threads 2, over the

Thread deflecting 5 are performed. In the present example, these are only two warp threads 2.1, 2.2, since a high extensibility of these warp threads 2 is assumed. The bending stiffness of the spring plate 7 is rather low in this case, so that a small increase in voltage in one of the two warp threads 2.1 already to a significant additional deflection of the Fadenumlenkelementes 5 and thus to a sufficiently high voltage reduction in the other

Warp thread 2.2 of the group leads.

The elastic deflectability of the Fadenumlenkelements 5 is selected on the structural design of the flexural rigidity of the spring plate 7, starting from an undisturbed position of the warp thread 2.1 in the upper compartment 21 by an additional deflection of this warp thread 2.1 to the gripper 1 such a voltage increase in the warp 2.1 is generated, characterized in that the Fadenumlenkelement 5 is additionally sufficiently elastically deflected in order to cause a reduction in tension in the warp 2.2 through which the Kettwächterlamelle 4.1 falls on the contact rail 4.2 at Kettfadenwächter. This then triggers a signal on the weaving machine, with which the weaving machine is preferably stopped immediately.

For warp threads 2.2 which are additionally deflected by the gripper 1 from its undisturbed position in the lower shed 22, of course, the same considerations apply to the design of the elastic deflectability of Fadenumlenkelements 4. The interpretation is preferably such that for both cases of disturbances secure monitoring of the thread overvoltage is guaranteed.

The Fadenumlenkelemente 5 of the loom of Figure 1 further have edge boundaries or thread guide elements 6, with which warp threads are prevented from slipping in the weft direction 23 from Fadenumlenkelement 5. In order to achieve reliable monitoring of thread overvoltages in the warp threads 2 during operation of the weaving machine according to FIG. 1, these are to be guided over the thread deflection elements 5 in accordance with the method described above.

REFERENCE CHARACTERS

1 weft insertion element

2 threads running in the warp direction

3 compartment picture elements

3.1 Heald of a shed element

4 warp stopper

4.1 Chain guard blade

4.2. contact bar

5 thread deflection

6 thread guide element

7 spring plate

7.1 subsegment

8 reed

9 tissue

20 warp direction

21 upper part

22 lower compartment

23 firing direction

24 binding point

Claims

1 claims

1 . Method for monitoring a thread overstress in a weaving machine with mechanical weft insertion elements (1), wherein threads (2) extending in a warp direction (20) from a thread supply via a thread monitor (4)

Elements for shedding (3) are fed, wherein falls below a certain voltage in one of the threads (2) by the thread monitor (4) generates a signal to the loom, characterized in that at least one group of in the warp direction (20) extending Threads (2.1, 2.2) between the thread supply and the shed forming elements (3) in such a way over an elastically deflectable Fadenumlenkelement (5) is performed that at

Exceeding a certain tension in one of the threads (2.1) of this group (2.1, 2.2) the Fadenumlenkelement (5) is deflected such that by this deflection, the tension in at least one other thread (2.2) of this group (2.1, 2.2) reduced so far is that the thread monitor (4) generates a signal.

2. The method according to claim 1, characterized in that the number of threads of the at least one group (2.1, 2.2) in the warp direction (20) extending threads (2) on the elasticity of these threads (2.1, 2.2) and on the elastic

Deflection of the Fadenumlenkelements (5) are tuned, that starting from an undisturbed position of the threads of this group (2.1, 2.2) in a top compartment (21) or in a lower compartment (22) of the weaving a disturbance of

Thread course by an additional deflection of one of these threads (2.1) to a weft insertion element (1) to such a voltage increase in this additionally deflected thread (2.1) leads that by the following

Voltage reduction in at least one other thread (2.2) of the group in question by the thread monitor (4) generates a signal.

3. The method according to claim 1 or 2, characterized in that in the warp direction (20) extending threads (2) band or wire-like material is used.

4. The method according to any one of claims 1 to 3, characterized in that a group in the warp direction (20) extending threads (2.1, 2.2), via the elastic 2 deflectable Fadenumlenkelement (5) are guided, consists of 2 - 20 threads (2).

5. Weaving machine with a device for monitoring a yarn overstretching with means for storing threads which extend in the warp direction (20), with mechanical weft insertion elements (1) and elements for shedding (3) and with a thread monitor (4), in the course the threads (2) between the device for storing the threads and the shedding elements (3) is arranged and with the falls below a certain thread tension in at least one of the thread monitor (4) monitorable threads (2) a signal on the weaving machine can be generated and with at least one Fadenumlenkelement (5), which in the yarn path of a group of threads (2.1, 2.2) extending in the warp direction (20), between the means for storing these threads (2) and the shed forming elements (3) is thereby characterized in that the elastic deflectability of the Fadenumlenkelements (5) in such a way to the number and the elasticity of a group of the Fadenuml is guided by an undisturbed position of these threads (2.1, 2.2) in a top compartment (21) or in a bottom compartment (22) of the loom by an additional deflection of one of the threads (2). 2.1) of this group to a weft insertion element (1) such a voltage increase in this additional deflected thread (2.1) can be generated, characterized in that the Fadenumlenkelement (5) is elastically deflected in a manner by which in at least one other thread (2.2) via this Fadenumlenkelement (5) guided thread group (2.1, 2.2) such a voltage reduction occurs that thereby over the

Thread monitor (4) a signal is generated on the loom.

6. weaving machine according to claim 5, characterized in that the

Thread deflecting element (5) has at least one thread guide element (6) with which in the warp direction (20) extending threads (2) in the weft direction (23) are feasible.

7. Weaving machine according to one of claims 5 or 6, characterized in that the Fadenumlenkelement (5) is designed as elastically deformable spiral spring. 3

8. loom according to one of claims 5 to 7, characterized in that a plurality of Fadenumlenkelemente (5) for a plurality of groups in the warp direction (20) extending threads (2) are arranged distributed over the width of the loom.

9. Weaving machine according to claim 8, characterized in that the Fadenumlenkelemente (5) are formed as bending springs of contiguous sub-segments (7.1) of a single spring plate (7).

10. Weaving machine according to one of claims 5 to 9, characterized in that the thread monitor (4) has a plurality Kettwächterlamellen (4.1) and at least one contact rail (4.2).