CH714658A1 - Method for operating a spinning station of a ring spinning machine after a Doffvorgang. - Google Patents

Abstract

Disclosed is a method for operating a spinning station (2) of a ring spinning machine (1) after a doffing operation, the spinning station (2) comprising a spindle (8), a ring traveler, a thread guide and a drafting device (5) assigned to the spindle (8). having. The method comprises the method steps that a thread break after the Doffvorgang at the spinning station (2) is detected and a maintenance carriage (9) moves to the spinning station (2) and fixes the yarn breakage. In this case, the amount of yarn on the cop (7) is checked before the removal of the yarn breakage by the service trolley (9) and if there is too little yarn on the cop (7) to guide the yarn to the drafting system (5) and to set is the cop (7) cleaned and a thread is attached to the empty cop (7), and the yarn is guided by means of the maintenance carriage (9) by ring traveler and thread guide to the drafting system (5) and attached there; and if there is enough yarn on the cop (7) to guide the yarn to the drafting system (5) and set, the yarn is guided by means of the maintenance trolley (9) by ring traveler and yarn guide to the drafting system (5) and attached there.

Description

description

TECHNICAL FIELD The present invention relates to a method for operating a work station of a ring spinning machine after a doffing process, a maintenance trolley and a ring spinning machine according to the independent claims.

State of the art Operator robots or maintenance trolleys which attach threads to ring spinning machines after a thread break are well known. In particular, the operating robot from EP 0 394 671 A2 may be mentioned here. The latter moves along a number of spinning positions, determines thread breaks and then tries to correct the determined thread breaks. First, the belt that drives the spindle is lifted off the spindle by means of a special spindle brake device and then the spindle is stopped. An auxiliary thread is also used. One end of the auxiliary thread is attached to a winder which can be moved around the spinning cop, in order then to be wound around the spinning cop. The auxiliary thread is then threaded through the ring traveler and the thread guide and brought into the area of the exit of the drafting system. The spindle and thus also the spinning cop are then driven again and the auxiliary thread is brought into the path of the stretched roving so that it is twisted with it.

If there is a thread break after doffing, it is disadvantageous that the maintenance car tries to fix this, there is too little yarn on the sleeve to successfully carry out a piecing process. This can result in the yarn being unwantedly pulled off the sleeve using the thread-searching device. The remaining layers of yarn on the core are too small after the thread search, so there is a risk that the yarn layers will be shifted or pulled off when the thread is pulled on.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method and a maintenance trolley which remedy a thread break after a doffing operation in such a way that the yarn is not moved or pulled off on the spinning cop.

The object is achieved by a method with the features of the independent claims.

The object is achieved in particular by a method according to the preamble of the method claim, which is characterized in that the amount of yarn on the bobbin is checked by the maintenance trolley before the thread break is remedied, and

- If there is too little yarn on the bobbin to guide and attach the yarn to the drafting system, the bobbin is cleaned of yarn and a thread is attached to the empty bobbin, and the yarn is guided to the drafting system by ring carriages and thread guides and is applied there; and

- If there is sufficient yarn on the bobbin to guide and attach the yarn to the drafting system, the yarn is guided to the drafting system by the ring carriage and thread guide and attached there.

This method can advantageously prevent the automatic piecing process from not succeeding, since there is too little yarn on the sleeve. The effectiveness and precision of the process is increased accordingly. The thread break can be determined, for example, by an individual spindle monitor or a single spindle drive of the spindle.

Although the method could in principle be carried out as standard throughout the entire spinning cycle, it is advantageously possible to carry it out only during piecing, i.e. while the first three layers are placed on the cop. A time limit, e.g. the first two to five minutes would also be conceivable.

The amount of yarn in the bobbin is advantageously checked by calculating the amount that has been wound on the bobbin, in particular by the amount of yarn over a time that the spindle has been running and a yarn number in correlation with the time the thread break is calculated. The amount of yarn can be calculated, for example, from the delivery of the yarn (in m / min) or determined by a sensor.

[0010] The head can be cleaned advantageously by suction with a thread search mechanism. This allows the cop to be cleaned completely and quickly.

In addition, it can advantageously be decided on the basis of a control of a maintenance cart whether there is sufficient yarn on the bobbin. The maintenance car can work autonomously. In another exemplary embodiment, it is possible for the machine control to make the decision and to notify the maintenance vehicle.

It is also advantageously possible that after the spinning process has been continued after the doffing process with an empty bobbin, no ring traveler movement has been detected, a thread is directly attached to the empty bobbin, and the yarn is used by the ring carriage and thread guide to the drafting device managed and set there. It is basically checked whether a thread was jammed in the clamping crown, i.e. that a thread break had already occurred before doffing.

CH 714 658 A1 The invention also relates to a maintenance trolley for performing a method according to one of the preceding claims, characterized in that the maintenance trolley comprises a controller which is designed to determine whether there is sufficient yarn on the bobbin and if there is too little yarn on the bobbin to guide and attach the yarn to the drafting system, clean the bobbin and attach a thread to the empty bobbin, and guide the yarn to the drafting system by means of the ring carriage and thread guide and start there; and if there is sufficient yarn on the cop to guide and attach the yarn to the drafting system, to guide the yarn to the drafting system by means of the ring carriage and thread guide and to apply it there.

The control of the maintenance cart is advantageously designed to calculate the amount of yarn on the bobbin that was wound onto the bobbin, and in particular the amount of yarn over a time that the spindle has been running, and a yarn number in correlation with that To calculate the time of the thread break.

The maintenance trolley advantageously comprises a device for finding the thread end and for suctioning the yarn and a device for attaching a thread to the empty bobbin.

The invention also relates to a ring spinning machine with a corresponding maintenance carriage.

BRIEF DESCRIPTION OF THE FIGURES Further advantages of the invention are described in the following exemplary embodiments, wherein

Figure 1 shows schematically a ring spinning machine with a maintenance car. and FIG. 2 shows a flow diagram of the method according to the invention;

demonstrate. The same features have the same reference symbols in different figures.

WAYS OF IMPLEMENTING THE INVENTION FIG. 1 schematically shows a ring spinning machine 1 according to the invention, which has a large number of spinning stations 2 arranged next to one another. The spinning stations 2 are arranged in a longitudinal direction x of the ring spinning _machine 1 between a head 3 _Ί and a foot 3 ₂ . Head 3 _Ί and foot 3 _{2 of} the ring spinning machine 1 can contain bearings, drives, controls, etc., which are necessary for the operation of the machine. As can further be seen, for example, at two spinning stations 2 shown schematically in FIG. 1, each spinning station 2 consists of a roving spool 4 which is arranged above a drafting unit 5 and on which a roving 6 is wound. The roving 6 runs from the roving spool 4 over the drafting unit 5, where it is stretched, in order then to be guided to a yarn formation element via a thread guide. A circumferential ring winds the finished yarn on a cop 7. The cop 7 is placed on a spindle 8. A maintenance carriage 9 moves along the ring spinning machine 1, which, in the event of a yarn break, moves to a corresponding spinning station 1 and automatically corrects the yarn break. The individual spinning stations 2 can be equipped with spindle monitors or other sensors for monitoring the ring traveler in order to detect a thread break. Alternatively or additionally, the spinning stations 2 can be equipped with individual spindle drives.

2 shows a flow diagram of the method according to the invention. The method relates to the starting process of a spinning station 2 of the ring spinning machine 1 after a doffing process. During the doffing by a doffer (not shown), a full cop 7 is removed from the spindle 8 and an empty cop 7 is placed on the spindle 8.

In a first method step 10, the spindle 8 is started again after doffing with the empty cop 7.

In a second method step 20 it is determined after doffing by means of the individual spindle monitor or another individual spindle monitoring that a thread break is fixed at a spinning station 2. In the case of the single spindle drive of the spindle 8, this could be determined, for example, via the torque or other existing data, a thread break. In principle, the process could be carried out as standard throughout the entire spinning cycle. However, it is also advantageously possible to carry it out only when piecing, i.e. while the first maximum of three layers are placed on the cop 7. A time limit, e.g. the first two to five minutes would also be conceivable. The maintenance carriage 9 then moves to the spinning station 2 and with the aim of eliminating the yarn break.

In a third method step 30, it is checked whether a thread is present at this spinning station 2. In principle, it is conceivable that no thread was pinched in the clamping crown, i.e. that a thread break occurred before or during doffing. On the basis of data as to whether a rotor signal of the ring traveler was detected at all or not, a decision is made as to whether one proceeds directly to the sixth method step 60 (selection on the left) or whether the thread breakage could be remedied by spinning on with maintenance trolley 9 and attachment. In this case, the method proceeds to fourth step 40 (right side selection). This basic check could take place from a higher-level machine control or in the control of the maintenance carriage 9.

In a fourth method step 40 it is checked whether the yarn length on the cop is sufficient to guide the yarn through the maintenance carriage 9 from the cop 7 through the ring traveler and the thread guide to the drafting device 5 and

CH 714 658 A1. The amount of yarn in the cop 7 can advantageously be checked by calculating the amount that was wound onto the cop 7 by the spindle 8. The amount of yarn can, for example, be calculated from the delivery of the yarn (in m / min) or determined by a sensor and then determined. The amount of yarn can thus be calculated, for example, by calculating a time that the spindle has run and a yarn number in correlation to the time of the yarn break. If there is not enough yarn on the tube, the method continues with the fifth method step 50 (left branch). If there is sufficient yarn on the tube, the method continues at seventh step 70 (lower branch).

In a fifth method step 50, the cop is cleaned of existing (rest) yarn. The cop is cleaned by a suction device located on the maintenance trolley, which is guided along the surface of the cop. Such a cleaning device is known, for example, from the unpublished PCT application PCT / IB 2017/057 254.

In a sixth step 60 of the method, a thread is attached to the empty bobbin by the maintenance carriage and in a seventh step 70 of the method, the maintenance carriage attaches the thread by guiding the thread through the ring traveler and the thread guide to the drafting system , There the yarn is attached to the existing fiber material in the conveying direction of the fiber material before or after a pair of output rollers of the drafting system. Such piecing processes by the maintenance car are known for example from EP 0 388 938 A1.

In an eighth and final step 80 of the method, the spindle is rotated again and the spinning process is started again.

Reference symbol list [0027]

Ring spinning machine

spinning units

Head of the ring spinning machine 1

3 ₂ feet of ring spinning machine 1

roving

drafting system

roving

Kops

spindle

service carriage

Process step: start after doffing

Process step: Thread breakage detected

Process step: Check whether the rotor signal is detected 40 Process step: Check whether the yarn length is sufficient 50 Process step: Clean the cops of yarn

Process step: attach thread to empty bobbin 70 process step: preparation cycle with maintenance trolley 80 process step: start of the spinning process X longitudinal direction of the ring spinning machine 1

Claims (15)

claims 1. A method for operating a spinning station (2) of a ring spinning machine (1) after a doffing operation, the spinning station (2) having a spindle (8), a ring traveler, a thread guide and a drafting device (5) assigned to the spindle (8) and Ring spinning machine (1) has a maintenance carriage (9) and a doffer, comprising the method steps - The spinning process is continued at the spinning station (2) after the doffing process with an empty cop (7); - A thread break is detected at the spinning station (2); - The maintenance carriage (9) moves to the spinning station (2) and corrects the yarn break; - The spinning process is continued, characterized in that the amount of yarn on the bobbin (7) is checked before the thread break is repaired by the maintenance carriage (9), and - If there is too little yarn on the bobbin (7) to guide and attach the yarn to the drafting device (5), the bobbin (7) is cleaned of yarn and a thread is attached to the empty bobbin (7), and that Yarn by means of the maintenance trolley (9) through ring traveler and thread guide to the drafting system (5) and attached there; and when there is sufficient yarn on the bobbin (7) to guide and attach the yarn to the drafting device (5), the yarn is guided to the drafting device (5) by means of the maintenance carriage (9) through ring travelers and thread guides and attached there. 2. The method according to claim 1, characterized in that the amount of yarn of the cop (7) is checked by calculating the amount that was wound on the cop (7). 3. The method according to claim 2, characterized in that the amount of yarn is calculated from the delivery of the yarn. 4. The method according to claim 2 or 3, characterized in that the amount of yarn over a time that the spindle (8) has run, and a yarn number is calculated in correlation with the time of the yarn break. 5. The method according to any one of the preceding claims, characterized in that the cleaning of the cop (7) is done by finding the yarn end on the cop and suction. 6. The method according to any one of the preceding claims, characterized in that the method is carried out after doffing, provided that there are no more than three layers on the cop (7). 7. The method according to any one of the preceding claims, characterized in that a thread break took place immediately before, during or after doffing at the job. 8. The method according to any one of the preceding claims, characterized in that it is decided on the basis of a control of a maintenance carriage (9) whether there is sufficient yarn on the cop (7). 9. The method according to any one of the preceding claims, characterized in that the thread break is determined by an individual spindle monitor or a single spindle drive of the spindle. 10. The method according to any one of the preceding claims, characterized in that after the spinning process after the doffing process with an empty cop (7) is continued, but no ring movement has been detected, a thread is attached to the empty cop (7), and the yarn is guided to the drafting system by the ring carriage and thread guide by means of the maintenance carriage (9) and attached there. 11. Maintenance trolley (9) for carrying out a method according to one of the preceding claims, characterized in that the maintenance trolley (9) comprises a controller which is designed to determine whether there is sufficient yarn on the cop (7) and if there is there is too little yarn on the bobbin (7) to guide and attach the yarn to the drafting device (5), clean the bobbin (7) and attach a thread to the empty bobbin (7), and thread the yarn using the maintenance cart ( 9) lead to the drafting system (5) by ring travelers and thread guides and start there; and if there is sufficient yarn on the cop (7) to guide and attach the yarn to the drafting device (5), to guide the yarn by means of the maintenance carriage (9) through ring travelers and thread guides to the drafting device (5) and to apply there. 12. Maintenance trolley (9) according to the preceding claim, characterized in that the control is designed to calculate the amount of yarn on the bobbin (7) that was wound on the, and in particular the amount of yarn over a time that the spindle has run, and to calculate a yarn number in correlation with the time of the yarn break. 13. Maintenance trolley (9) according to one of claims 11 or 12, characterized in that a device for finding the thread end and for suctioning the yarn is present. 14. Maintenance trolley (9) according to one of claims 11 to 13, characterized in that a device is provided to attach a thread to the empty bobbin (7). 15. ring spinning machine (1) with a maintenance carriage (9) according to one of the preceding claims 11 to 14.