EP0648875B1 - Method for preventing weaving bar in a loom - Google Patents

Description

The invention relates to a method for avoiding Tissue marks in a weaving machine with a Reeds that are set to a target stroke distance is.

To avoid starting points in the tissue known various solutions that relate to the Regulate the edge of the goods in the weaving machine. A such a method is known from DE-A-41 37 681.

EP-A-350 446 describes a method for operating a Terrycloth loom known, in which the sley is driven by the main drive of the weaving machine and is operated by a separate drive that through a sequence of freely programmable pulses is controlled individually. That’s why well-known terry rhythms with different pile heights executable.

The invention has for its object a method to avoid tempering spots in the tissue in such To create loom.

This object is achieved with the characterizing features of claim 1 solved.

The advantage that can be achieved with the invention is therein see that terry and smooth fabrics with program Shot density can be made.

Advantageous embodiments of the invention result from the dependent claims.

In the following the invention with reference to the enclosed Drawings explained.

Fig. 1

eine Frottierwebmaschine, bei der das erfindungsgemässe Verfahren zur Anwendung kommt;

Fig. 2

ein Flussdiagramm des Verfahrensablaufes zur Stillsetzung der Maschine beim Auftreten eines Schussfehlers;

Fig. 3

ein Flussdiagramm des Verfahrensablaufes zur Stillsetzung der Maschine beim Auftreten eines Stopp-Ereignisses;

Fig. 4

ein Flussdiagramm des Verfahrensablaufes zum Wiederstart der Maschine.

Show it:

Fig. 1

a terry weaving machine in which the method according to the invention is used;

Fig. 2

a flowchart of the process flow for stopping the machine when a shooting error occurs;

Fig. 3

a flowchart of the procedure for stopping the machine when a stop event occurs;

Fig. 4

a flowchart of the procedure for restarting the machine.

The procedure in question is used here to avoid weaving errors, taking the course of the procedure depends on whether a weft fault, e.g. a Weft break, partial weft, etc. or another Stop event, e.g. a warp thread break, a shutdown the weaving machine, etc.

The following is an embodiment of the method described when weaving 3-weft terry fabrics applied.

Fig. 1 shows a terry loom. Of a Basic warp beam 1, the basic chain 7 runs over a Spanning tree 4 to the shed 9. The fabric 10 is over a Breast boom 6 and a take-off roller on a goods boom 3 deducted. The pile chain 8 is pulled over by the pile warp beam 2 a pendulum roller 5 passed to the shed 9. A reed 12 the sley 11 is from a Loom main drive shaft 13 via a Shutter control device 14 driven. Furthermore, a Servo motor 15 provided with the The shop control device is drive-connected to the Set stop distances. The servo motor 15 is included a control device 16 electrically connected to the Servo motor 15 in accordance with a control program head for.

If a weft break occurs during the weaving process, the corresponding monitoring devices apply an error signal to the control device 16 which, in a control step by the servo motor 15, sets the shutter control device 14 to a suggested distance VD _max , VD _max compared to VD _target or AD _target at least by it is so much greater that the reed and any existing partial weft no longer changes the position of the previously correctly inserted weft, ie there is a minimal distance to the previously correctly inserted weft. At this time, the main shaft of the weaving machine rotates until a stop position is reached, in which a control step "stop initiation" takes place. In the event that an automatic stop of the weaving machine is initiated, the main shaft is rotated in the running direction in order to achieve a predetermined position, for example the end of the trade. In the following, a control step "shot search" is initiated which, depending on the specialist position, consists of two independent search processes. After the corresponding search process has been completed, the weaving machine is stopped (FIG. 2).

If another stop event occurs during the weaving process, for example a warp thread break, a manual shutdown, etc., according to the invention the servo motor allows the shutter control device to reach the suggested distance VD _max either directly after the stop event or before the reed makes the full stop again - Position reached, adjusted.

As with the weft break, the follows after reaching Stop position the second control step "stop initiation". If an automatic stop is initiated, a follows Control step "machine stop". Is a Technical equality is required in one tax step changed the position. After changing the Specialist position or an unequal specialist position a control step "shot hunting" initiated. After The weaving machine is completed at the end of the weft search process shut down and with elimination of the fault for the Prepared for restart (Fig. 3).

In the control device 16 (FIG. 1) the characteristic values are: Target proposal distance, target full stop distance, Shot density, number of proposal shots by Full stop and fabric type saved. Furthermore, in Depending on these parameters, a correction process which of the correction steps are saved specifies. It is noted that further Characteristic values can be taken into account.

It is also provided that the correction process manually regardless of the stored characteristic values can be entered, with article specifics can be taken into account.

Here, with the restart of the weaving machine Proposed distance and full stroke values corrected. This correction is done step by step manually adjustable correction steps, which each Assigned stop, and repeated until the target stroke distance for the proposal shot and the Full stop shot is reached. The correction can within one or more shot groups. Here, the change in length of the stop distance for every group or for every attack the same or be different.

The machine is usually restarted with a manually triggered start command. In one Control step is the weaving machine in a start position brought. This process is independent of whether Terry or smooth fabric is made.

When the machine is restarted, the shed control device is drive-connected to the main shaft of the machine. In order to put the weaving machine from standstill into the operating state, one or more empty shots can be carried out when the weaving machine starts up, VD _{max being set} while the weaving machine starts up and the number of empty shots being freely selectable.

The procedure for starting the weaving machine after a previous weft break is described below. Taking into account the entered parameters and on the basis of the information that the first proposal shot has been broken, the proposal distance VD _{1 is} set, which is the sum of the target proposal distance VD _target plus / minus a correction value Vk ₁ . Thus, the first suggestion shot, for example in the case of a thin spot in the fabric, is shifted beyond the target suggestion distance, or in the case of a thick spot in the fabric over a distance which is shorter than the target suggestion distance, in the warp direction. Subsequently, the second proposal shot is entered and the proposal distance VD _{2 is} set, which is the sum of the target stop distance VD _target plus / minus a correction value Vk ₂ . The second proposal shot is thus also shifted in the warp direction with respect to the target proposal distance VD _target . When the full shot is entered, the stroke distance AD _{1 is} set, which is the sum of the desired full stroke distance AD _desired plus / minus a correction value Ak ₁ . This shifts the weft group in the warp direction with respect to the target full stop distance AD _target . If the correct position of the weft group with respect to the fabric edge is achieved through these correction processes, the further weaving process either takes place without further corrections of the values VD and AD, that is to say the fabric produced subsequently has a weft density and loop height with the specified values, or with further corrections for at least one additional shot group with changed values for VD and AD compared to the previously fired shot group. The correction values can have the same or different values (FIG. 4).

If the correct position is not reached, which can be determined on the basis of visual or automatic monitoring, the values VD ₁ , VD ₂ and AD _{1 are changed} for the next same error event. If a thin or thick spot in the tissue is found, the full stroke distance AD is changed, and in the case of a thin spot the value of AD is increased and in the case of a thick spot the value of AD is decreased. If a discrepancy in the loop height is found, the values VD ₁ and VD _{2 are} changed; if the loop is too high, the values of VD ₁ and VD _{2 are} reduced, and if the loop is too low, the values of VD ₁ and VD ₂ enlarged.

If the warp thread breaks, the Weaving machine usually with a full weft started. Therefore, starting from As a rule, the procedure is described.

With a control step "full stop" the correction process is initiated and a stop distance AD _{1 is} set, which is the sum of the desired full stop distance AD _target plus / minus a correction value Ak ₁ . The weft group is thus shifted accordingly in the warp direction with respect to the target full stop distance AD _target . If the correct position of the weft group with respect to the fabric edge is achieved by this correction process, the further weaving process either takes place without further corrections of the values VD and AD, that is to say the fabric produced subsequently has a weft density and loop height with the specified values, or with further corrections for at least one additional shot group with changed values for VD and AD compared to the previously fired shot group. The correction values can have the same or different values (FIG. 4).

If the correct position is not reached, which is due to visual or automatic monitoring the value is changed. Will be a thin or Thick spot in the tissue is determined Full stroke distance AD changed at one Thin point, the value of AD is increased and at one Thickness decreases the value of AD.

In the control process, the target stop distance in Meaning of an extension or shortening to Events, e.g. Thick and / or thin places, too avoid so that tissue, e.g. Terrycloth or Smooth weave, produced with a weft density according to the program becomes.

Claims (10)

1. Method for the avoidance of stop marks in the fabric in a loom having a reed, which is set to a target beat-up distance, characterized in that the reed stop is so controlled that the target beat-up distance is altered in the sense of a shortening or lengthening, in order to avoid stop marks, for example thick and/or thin places.
2. Method in accordance with claim 1, characterized in that, in the case of a stop event of the loom, a first beat-up distance VD_max is set, as a function of a signal, in order to prevent contact of the reed or of a partial weft with the previously correctly inserted weft thread, in that, during restarting of the loom, a second beat-up distance VD₁, AD₁ is set, and in that at least one correction process is carried out in order to return the second beat-up distance to the target beat-up distance.
3. Method in accordance with claim 2, characterized in that the setting of the first beat-up distance is initiated directly by a mispick signal.
4. Method in accordance with claim 2,characterized in that the setting of the first beat-up distance is initiated by an error signal or a signal which occurs before the reed reaches the full beat-up position a further time.
5. Method in accordance with claim 2, wherein the weft threads are beaten up in groups, characterized in that the second beat-up distance is set for each weft thread.
6. Method in accordance with claim 5, wherein the group is beaten up by at least two partial beats and one full beat, characterized in that a correction process is associated to each of the two beat types, the correction processes being independent of one another.
7. Method in accordance with one of the claims 5 or 6, characterized in that the correction process includes at least one correction step.
8. Method in accordance with claim 7, characterized in that the correction process includes several equal or unequal correction steps.
9. Method in accordance with claim 2, wherein at least one empty pick is inserted, characterized in that the first beat-up distance is retained.
10. Method in accordance with claim 2, wherein at least one empty pick and, following this, individual wefts are inserted in the sense of the continuation of the weaving process, characterized in that the first beat-up distance is retained during the insertion of the empty pick, and the second beat-up distance is set during the insertion of the individual wefts.

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