EP0950740A1 - Process to avoid weaving faults and loom for carrying out this process - Google Patents

Abstract

A computer is used to control the actions of a loom in operating the warp let-off and the fabric takeoff, the movements of the shed, and the advance movement of the leading fabric edge. During the operation of the loom, the computer applies a continuous control on the auxiliary motors so that the selvage shifts are compensated through distortions at the sley at different loom speeds. The computer gives the selvage movement through the equation DELTA S=k x n<2>, where DELTA S is the selvage shift against n=0, n is the rotary speed of the loom and k is a factor of influence. At the same time, all the auxiliary drives for the fabric beam and one or more warp beams for the ground and pile warps are controlled electronically. The factor of influence is derived empirically by setting a min. start value, observation of the weaving and registering weaving faults. The min. start value is increased in one or more steps with suitably small quantizing's and especially 0.5 or 1.0 values, to give a final value. The selvage shift DELTA S is in a range of 0-2 mm plus or minus 10% or a smaller tolerance. An Independent claim is included for a loom (20) with a number of auxiliary drives (2,3) for the fabric winding beam and the warp or pile warp beam, and a position control (4). They are controlled continuously during weaving, by a computer.

Description

The present invention relates to an avoidance method weaving defects in the weaving of a weaving machine according to the preamble of claim 1, and a weaving machine to carry out this method according to the preamble of claim 4.

Such a method or weaving machine is can be found in DE-C2-41 37 681 and also in EP-A1-0 629 726.

The cause of fabric defects, also called standpoints or contact points (open and tight spots), can be explained by the fact that the weaving rivet's stop position (due to the inertial forces) is closer to the finished fabric than the creep speed of approx .20 min ^-1 . Therefore, an error occurs when changing between the two operating modes. In the case of a transition from high speed to crawl speed, an open tissue site occurs, and consequently, in the case of a transition from crawl speed to high speed, a dense tissue site occurs. This problem can of course also occur when changing the weaving speed within a woven fabric, for example from 500 min ^-1 to 250 min ^-1 .

DE-C2-41 37 681 describes a method for prevention a weft in a weaving machine in which the Woven goods and thus the goods edge at a standstill or crawl or positioning of the loom is shifted to then avoid weft strips when restarting the weaving machine.

It is similar with EP-A1-0 629 726. According to this teaching if the weaving machine is stopped after an interference signal the goods edge is shifted to an alternative position. Due to the type of fabric, the warp thread and of the weft, coordinated starting procedure, will be contact points prevented in the tissue.

A similar principle is also used in the others Publications worked, see e.g. EP-A1-0 629 725, EP-B1 0 151 940, EP-B1-0 594 250, EP-A1-0 567 428, CH-A5-668 997 and DE-U-91 08 796.

In the prior art, these locations are tried compensate for by the displacement of the fabric edge in front of the Creeper function. As a result, they are necessary Shifts in the fabric edge only requested and carried out and the enforcement of which must be monitored. This approach only works when the loom stops moving into the creeper function. In practice, e.g. after stopping the loom so long on the switch Crawl gear pressed until the auxiliary drives in the goods edge have brought appropriate position. Happened in that time nothing at all regarding the weaving process. Only after the goods are moved by the auxiliary drives The weaving machine then starts the weaving process in creeper mode and the finger can be taken off the creeper switch become. An automatic correction of the goods edge by the auxiliary drives, e.g. when changing weft yarn of weaving speeds within a fabric not possible with the state of the art.

The present invention is therefore based on the object the method described at the beginning and the weaving machine to improve this method so that they safely avoid the disadvantages described and with easier and safer handling any web errors in the Tissue formation can be excluded.

Another object of the invention is to operate the Make the loom as quickly as possible, so that on the positioning the goods edge at a restart or the like can be dispensed with.

This task and the goal are solved or achieved by that the computer is running continuously the loom controls several auxiliary drive motors in such a way that depending on the weaving machine speed otherwise Edge shifting of deformations at the sley is balanced.

Because the implementation of this calculation is continuous and reproducible within the computer of the invention Control device takes place, this procedure is required also with speed variations within the weaving process, e.g. due to different weft yarns (e.g. yarn fine and material) no manual corrections or Re-adjustment of the goods edge.

In the procedure according to the invention - in other words - the cause of the stand or contact points in the tissue is compensated from the outset by the fact that the tissue edge is supported by the auxiliary drives according to a mathematical relationship (ΔS = kxn 2nd ) is positioned around the dimension of the modified stop edge. This is done continuously and reproducibly while the weaving machine is running. When executing the creeper function from the state of the weaving machine, for example, no advance movements of the goods edge are required to avoid contact points.

When starting the weaving machine at full weaving machine speed, the edge of the goods is not shifted in the prior art. Since the weaving machine has often not yet reached its final speed at the first weft stop, there may be an open spot in the fabric. In the procedure according to the invention, the fabric edge control continuously adapts the fabric edge to the current weaving speed. Even if, for example, after the start of the weaving machine, the first weft takes place at approx. 250 min ^-1 , the second then at 470 min ^-1 and the final speed of 500 min ^{-1 is} reached only after the third weft take, there are no starting points (open Put).

The displacement of all auxiliary drives for the goods tree and the warp beam or beams takes place simultaneously. All auxiliary drives work on the principle of the "electric wave", i.e. the absolute synchronicity of all auxiliary drives The main shaft of the weaving machine is done by electronic Control.

When the weaving machine starts, the motors of the turn the Warp beams only with the gear factor calculated last Main shaft encoder. After the settling time of the dancer systems of the warp beams, becomes the position controller of the dancer systems switched on. If the position controller detects an increasing or decreasing Thread tension, so the corresponding warp beam accelerated positively or negatively via the control system, continues the gear factor becomes proportional at the same time re-adjusted to the warp beam diameter.

This new procedure for drive and Control can be used especially in weaving machines for flat fabrics, Weaving machines based on the push-nub-pile principle work (e.g. for terry fabrics) and with double pile weaving machines (e.g. for velvet and plush fabrics) become.

Various exemplary embodiments are described below the drawing explains the better understanding serve the invention, but the invention in no way should restrict.

Fig. 1:

eine schematische Seitenansicht einer erfindungsgemäß ausgerüsteten Flachgewebemaschine,

Fig. 2:

eine schematische Seitenansicht einer erfindungsgemäß ausgerüsteten Webmaschine, die nach dem Schub-Noppen-Pol-Gewebe-Prinzip arbeitet und

Fig. 3:

eine schematische Seitenansicht einer erfindungsgemäßen Doppelflorwebmaschine mit Schaftmaschine, die ebenfalls nach dem erfindungsgemäßen Verfahren arbeitet.

It shows:

Fig. 1:

2 shows a schematic side view of a flat weaving machine equipped according to the invention,

Fig. 2:

is a schematic side view of a weaving machine equipped according to the invention, which works on the push-nub-pile principle and

Fig. 3:

is a schematic side view of a double pile loom according to the invention with a dobby, which also works according to the inventive method.

Fig. 1 shows a flat weaving machine 20 with a main motor 1, an adjustable auxiliary drive 2 for the goods tree, an adjustable auxiliary drive 3 for the warp beam and one Position controller 4 for determining the warp thread tension. The auxiliary drives 2 and 3 work on the principle of electric shaft, driven by the main motor 1 Main shaft of the weaving machine 20, these auxiliary drives 2 and 3 continuously by the computer (not shown) in the weaving machine control are influenced or regulated.

FIG. 2 shows a weaving machine 30 which works according to the push-nub-pile principle works (e.g. a terry loom). Regarding the drives described in the flat weaving machine 20 1, 2 and 3 and position controller 4 for the basic chain, come with these types of weaving machines 30 the auxiliary drive 5 of the warp beam for the pile chain 5 and the associated one Position controller 6 added. This auxiliary drive 5 is like the other auxiliary drives 2 and 3 constantly by the Computer in the weaving machine control influenced or regulated.

The drawing Fig. 3 shows a double pile loom 40 with Dobby and a main motor 1, an auxiliary drive 2 for the goods tree, one or more auxiliary drives for one or more pole pulling booms 7, 8 and 9, each pole pulling boom controlled by its own adjustable auxiliary drive becomes. However, it is also common to have several pole trees switched on and off by a clutch, with two auxiliary drives for the basic warp beam regulators 10 and 11 and the associated position controllers 12 and 13 and one or several auxiliary drives for the pile chains, for example 14, 15 and 16 with the associated position controllers 17, 18 and 19th

With a jacquard system, the auxiliary drives for the Position controller and the pole warp beams, with the corresponding Position controllers, one or more may come for this Auxiliary drives for mirror chains with the corresponding position controllers added.

All of these auxiliary drives are in constant use according to this invention influenced by the computer in the weaving machine control or regulated.

The factors k for weaving machines according to the invention were determined by experiments. For a wide variety of weaving machine types a series of tests is required, through which an error rate of approx. ± 10 ° at a certain speed the value k is determined and recorded in tabular form becomes. The error rate can be customized through manual Intervention in the weaving machine control balanced become. The weaving machine, type 260 AIR-F TERRYFLEX, was the starting point for the tests is assumed to be k with 5, with the final values being 6-7-8-8.5-7.5-8 Value k = 8 was determined.

Depending on the speed of the weaving machine, the computer now calculates the value ΔS according to the formula mentioned above ΔS = kxn 2nd , for type 260 AIR-F TERRYFLEX, e.g. at a speed of 500 min ^-1 the value 8 x 500 ² = 2,000,000. This value represents the number of angular steps by which the motors of the auxiliary drives have to be adjusted in order to achieve the optimal position of the stop position (in this case 262144 = 2 ¹⁸ angular steps (increments) mean one revolution of the motor). If the weaving machine is now operated at a different speed, for example at 20 min ^-1 (creeper speed), the computer calculates in this case
ΔS = 8 x 20 2nd = 3200 . The motors of the auxiliary drives therefore only need to be adjusted by 3,200 angular increments.

Claims (4)

Process for avoiding weaving errors in fabric formation in a weaving machine which has a warp let-off device, a goods take-off device, a shed forming device, a sley and main and auxiliary drive motors has to move the front The edge of the fabric is controlled by a computer are characterized in that the calculator continuously during the operation of the weaving machine controls several auxiliary drive motors in such a way that each after weaving machine speed otherwise due to deformations Goods margin shift occurring at the sley is balanced. A method according to claim 1, characterized in that the computer moves the edge of the goods according to the following equation ΔS = kxn 2nd , calculates what

ΔS

= Goods edge shift compared to n = 0

n

= Speed of the weaving machine

k

= Influencing factor,

At the same time, all auxiliary drives for the goods tree and one or more warp beams for the basic and possibly the pile chain or for one or more pole pulling beams are electronically controlled and k is determined empirically by the following steps: Setting a minimum output value, Observing the weaving process, Detection of web defects, Increase the minimum, defined k-value in one or more steps with arbitrarily small quantulations, in particular 0.5 or 1.0 values, setting a final value. A method according to claim 1 and 2, characterized in that the edge shift ΔS in the range of 0 up to 2 mm ± 10% or less tolerance becomes. Weaving machine for carrying out the method according to a or more of the preceding claims, characterized in that that several auxiliary drives for the goods tree, one or more warp beams or pile pull beams and associated position controllers are provided, the continuously in operation by a computer like this be controlled so that they compensate for the calculated Carry out goods edge shift.

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