WORKPLACE OF A TEXTILE MACHINE

Description

[0001] The invention relates to a work station, in particular a spinning and / or winding station, of a textile machine according to the preamble features of claim 1.

[0002] In connection with workstations, particularly spinning and / or winding stations, of a textile machine, e.g., spinning machines and winding machines, it is known to position a controlled yarn storage unit upstream of the changing devices along a yarn path for winding bobbins, e.g., conical cross bobbins. These yarn storage units serve to adapt the yarn sag occurring during winding the bobbins to the constant yarn delivery speed, e.g., of a spinning device or spinneret take-up device. In known textile machines, the take-up bobbin is usually held in a pivotally mounted bobbin frame of a winding device downstream of the changing device during the winding process or bobbin travel and is usually driven by a friction roller via a friction connection or individually.Specifically, the winding speed of the take-up bobbin, depending on its wound diameter, corresponds to the constant yarn delivery speed, for example, by the spinning device. During winding, the yarn is laid across the bobbin width, particularly in a crisscross pattern, by means of the changing device. Due to the constant yarn delivery speed, the yarn loosens periodically. Therefore, to maintain the desired yarn tension, it is necessary to compensate for this sag as the yarn's working path shortens.

[0003] Besides compensating for thread sag, it is essential to maintain a largely constant thread tension during the winding process. Prior art, such as EP 2 955 142 A1, already describes the design of thread storage units with a thread guide arm that pivots into the thread path, thus temporarily extending the length of the thread's regular working path by forming loops. The thread guide arm is typically mounted and positioned about a pivot axis transverse to the thread path via a controllable electric drive. The electric drive is controlled by a control system that receives its output information from a thread tension sensor.

[0004] Depending on the thread tension present during winding, the control system reacts by means of a defined control of the electric drive and consequently of the thread guide arm, which can reduce or increase the thread tension.

[0005] However, the known systems have the disadvantage that, especially at higher winding speeds, they are not suitable for keeping the thread tension permanently constant, particularly when frequent changes in thread tension occur due to various influences.

[0006] Based on this, the invention aims to provide a thread storage unit that reliably maintains a largely constant thread tension during the winding process.

[0007] The invention solves the problem by a work station comprising a thread storage unit according to the features of claim 1 and by a method for adjusting a thread tension at such a work station according to the features of claim 11.

[0008] Advantageous embodiments of the invention are specified in the dependent claims.

[0009] According to the invention, the workstation is equipped with a thread delivery device for supplying a thread, a changing device for changing the supplied thread, and a thread winding device for winding the changed thread onto a take-up spool. The thread delivery device, the changing device, and the thread winding device are arranged along a thread path for the corresponding processing of the thread. The thread path is a path from the delivery point to the winding point, along which the thread travels during its journey on the spool without being influenced by the thread storage unit. The thread storage unit is also arranged along the thread path between the thread delivery device and the changing device in order to push the running thread out of the thread path during its journey on the spool by means of the pivoting movement of the thread guide arm.Particularly preferably, the thread guide arm is arranged along the thread path between two thread guide rollers or eyelets, over or through which the thread is guided during its travel around the spool. The thread guide rollers or eyelets can be supported by a paraffin waxing unit located upstream of the changing device along the thread path and arranged upstream of a paraffin body of the paraffin waxing unit. This allows the thread storage unit to be positioned close to the changing device, utilizing the lateral back-and-forth movement of the thread generated by the changing device, perpendicular to the thread path, for uniform wear of the paraffin body across its width extending perpendicular to the thread path and for uniform paraffin waxing of the thread.

[0010] A characteristic feature of the workstation according to the invention is that the thread storage unit has a guide arm pivotably mounted about a pivot axis and a controllable drive unit for reversing the pivoting of the thread guide arm, wherein the thread guide arm is freely rotatable and has a magnetically acting first coupling element arranged at a distance from the pivot axis. Furthermore, the drive unit has a second magnetic coupling element, adjustable relative to the first coupling element and acting magnetically repulsively towards the first coupling element.The second magnetic coupling element is arranged on the drive unit so that it can be brought into operative contact with the first coupling element via the drive unit, whereby an adjustment of the second coupling element in the direction of the first coupling element causes a corresponding displacement of the first coupling element, and thus a pivoting of the thread guide arm.

[0011] In contrast to previously known thread storage units, in which the thread guide arm is directly forced to rotate on the drive shaft of the drive unit, for example via a stationary bearing, and the force transmission consequently occurs strictly through components in contact with each other along the force flow, the thread guide arm according to the present invention is now freely rotatable, in particular mounted on the drive shaft of the drive unit. This allows the rotational force generated by the drive shaft to be transmitted to the thread guide arm without contact, utilizing magnetically acting means. According to the invention, the first and second coupling elements are aligned with each other such that they exert a repulsive magnetic effect on one another.Consequently, when the drive unit moves the second coupling element towards the first coupling element, the repulsive effect between the first and second coupling elements causes the first coupling element to move in the same direction as the second. This movement, in turn, causes the thread guide arm to pivot around its axis. Therefore, the thread guide arm is moved around its pivot axis without physical contact via the drive unit, depending on the set position of the second coupling element attached to the drive unit.

[0012] By pivoting the thread guide arm around its pivot axis into the thread path, the thread guide arm creates a loop-shaped thread path in the area of ​​the thread storage unit. Preferably, the thread guide arm engages with the thread in the area between two thread guide rollers or eyelets arranged along the thread path to create a defined loop. The drive unit enables contactless adjustment of the thread guide arm via the two coupling elements. If excess thread is generated during the winding process, leading to a decrease in thread tension, this excess is collected in a loop between the preferably provided pair of thread guide rollers or eyelets and the thread guide arm. Conversely, if less thread is generated during the winding process than is expected from the take-up spool, for example, the excess thread is collected in a loop between the preferably provided pair of thread guide rollers or eyelets and the thread guide arm.When the cross-wound bobbin is required, increasing the thread tension, the necessary thread length is released from the loop by retracting the thread guide arm. For this to occur, the second coupling element is adjusted via the drive unit in such a way that the thread guide arm pivots in the opposite direction to the thread, with the thread tension acting upon it resulting from this retraction. The thread guide arm thus follows the return movement of the second coupling element and releases the required thread length in a defined manner.The thread storage unit thus makes it possible to keep the thread tension constant at a precise and high frequency via the freely rotatable thread guide arm, so that a winding process can be carried out even at particularly high winding speeds, whereby the production of both cylindrical and conical winding bobbins can be carried out with particular reliability.

[0013] Ideally, the thread guide arm moves in the direction of the thread, or in the opposite direction, without changing the distance between the first and second coupling elements, and thus without changing the magnetic spring force resulting from the distance between the two coupling elements. Preferably, this movement of the thread guide arm can be controlled by a control system that drives the drive unit and a sensor unit that can be connected to the control system to transmit acquired sensor information. The control system is preferably designed to evaluate and assess the transmitted sensor information and to control the drive unit in a defined manner based on the evaluation result. The control system preferably comprises a control unit and an evaluation and assessment unit.These units can be one and the same unit or separate units. Two units can also be implemented as a single unit. Furthermore, the control system can be an integral part of the yarn storage device or a separate component. The arrangement of the control system is also freely selectable. For example, the control system can be located at a workstation encompassing the yarn storage unit, in a central machine control system, and / or separately from the textile machine. Redundant control through the provision of two such mutually checking or verifiable control systems is also possible.

[0014] The sensor unit, which can be connected to the control system, can preferably be used to detect the rotational movement and / or the position of the thread guide arm. The sensor information acquired by the sensor unit can then also be used to determine changes in the distance between the two coupling elements resulting from changes in thread tension. If the thread guide arm is in a position shifted towards the second coupling element compared to the position set by the control system—i.e., if the distance between the first and second coupling elements decreases—then the magnetically generated spring force acting between the first and second coupling elements increases.Taking into account a known characteristic curve of the magnetic spring force, previously stored in the control system or in a readable storage unit coupled to the control system, the control system can determine the thread tension acting on the thread. Subsequently, the thread tension can be checked, adjusted, and / or kept constant via the control system by changing the position of the second coupling element relative to the first coupling element by appropriately controlling the drive unit.

[0015] The thread storage unit thus makes it possible to keep the thread tension constant at a particularly precise and high frequency.

[0016] The design of the displacement of the second coupling element relative to the first coupling element by means of the drive unit can, in principle, be implemented in any way. For example, linear drives are conceivable that adjust the second coupling element linearly in the direction of the first coupling element perpendicular to the pivot axis, thus causing a displacement of the thread guide arm.

[0017] According to a particularly advantageous embodiment of the invention, the second coupling element is arranged on a support that is adjustable about the pivot axis of the thread guide arm by means of the drive unit, in particular coaxially. According to this embodiment of the invention, the second coupling element is adjustable about the pivot axis of the thread guide arm, wherein for this purpose the second coupling element is arranged on a support connected to the drive unit. The rotation of the support about the pivot axis of the thread guide arm allows for the use of particularly space-saving rotary drives for adjusting the second coupling element.Furthermore, a rotation of the second coupling element, which is preferably arranged at the same distance from the pivot axis as the first coupling element, provides a particularly uniform and reliable adjustment, so that a particularly precise displacement of the thread guide arm can be achieved by the control system via a displacement of the carrier.

[0018] The arrangement of the first coupling element on the thread guide arm is generally freely selectable. According to a particularly preferred embodiment of the invention, the first coupling element is detachably attached to the thread guide arm and / or the second coupling element is detachably attached to the drive unit. This embodiment of the invention makes it possible to easily replace the first and / or second coupling element as needed, so that adjustments to different production conditions, which may require different magnetic effects, can be made easily. Furthermore, maintenance and repair work can be carried out particularly easily and quickly.

[0019] The design of the drive unit for relocating the second coupling element, in particular the carrier, is generally freely selectable, and various motor drives can be used. However, according to a particularly advantageous embodiment of the invention, the drive unit comprises an electric motor, in particular a stepper motor, with a drive shaft that is rotationally fixed to the carrier and on which the thread guide arm is freely rotatable. Preferably, the guide arm has a bearing unit, in particular a bushing element, at a free end, by means of which the thread guide arm can be placed onto the free end of the drive shaft. The bearing unit is designed to mount the thread guide arm freely rotatable on the free end of the drive shaft, independent of any rotational movement of the drive shaft, i.e., without torque.Preferably, the thread guide arm has a thread guide section, in particular a thread guide eyelet or roller, at its further free end for contacting and guiding the thread. This allows the leverage of the thread guide arm to be utilized to its maximum extent. Other locations for both the bearing unit and the thread guide section along the longitudinal axis of the thread guide arm, selected as required, are also conceivable according to a further preferred embodiment.

[0020] According to this embodiment of the invention, the reversing electric motor enables particularly precise adjustment of the support about the pivot axis of the thread guide arm. Furthermore, the drive shaft serves to mount the thread guide arm so that it can rotate freely. A freely rotatable mounting or free rotation generally refers to a torque-free connection between the drive shaft and the thread guide arm, so that the drive shaft serves solely to pivot, and in particular to pivot, the thread guide arm, but does not transmit any torque to it.Furthermore, a corresponding design of the thread storage unit enables its particularly compact design, whereby it is ensured in a particularly reliable manner that a second coupling element arranged on the carrier can be adjusted around the drive shaft over the same circumference as the first coupling element, which is arranged on the thread guide arm at a corresponding distance from the axis of the drive shaft.

[0021] The design such that the first and second coupling elements produce a magnetic repulsion effect towards each other is fundamentally freely selectable. For example, the first and / or second coupling element can be designed as electromagnets whose magnetic fields are aligned to generate a repulsive effect. The electromagnets can be controlled via the control system, allowing different magnetic fields to be generated as needed, thus enabling the repulsion effect to be adjusted and, in particular, regulated via the corresponding control system.

[0022] According to a particularly advantageous embodiment of the invention, the first and second coupling elements are designed as permanent magnets. The use of permanent magnets as coupling elements, which are arranged appropriately on the thread guide arm and the carrier, represents a particularly simple, low-maintenance, and cost-effective way to provide a magnetic repulsion effect. The desired repulsion effect can be determined by selecting the appropriate permanent magnets.

[0023] The connection of the carrier to the drive unit, in particular to a preferably provided drive shaft of an electric motor, can be achieved by simple flange connections. However, according to a further development of the invention, the carrier is arranged on a coupling disk that is coaxially connected to the drive shaft and non-rotatably connected to the drive shaft. The use of a coupling disk ensures particularly reliable displacement of the carrier and the second coupling element connected to the carrier about the pivot axis of the thread guide arm. The coupling disk can bear against a corresponding counter surface of an advantageously provided electric motor for planar guidance.

[0024] A sensor unit, which can be positioned at any location, is used to detect the rotational movement and / or position of the thread guide arm, and in particular to detect deviations from the position of the thread guide arm compared to the position set by the control system via the drive unit. According to a preferred embodiment of the invention, the sensor unit is designed and arranged to detect the angle of rotation and / or position of a connecting element that is fixedly connected to the thread guide arm and arranged coaxially to the drive shaft. The sensor unit is further preferably arranged coaxially to the connecting element. According to this embodiment of the invention, a connecting element that is fixedly connected to the thread guide arm extends section by section into the sensor unit, which is arranged at a distance from the end of the drive shaft.A corresponding arrangement of the sensor unit, in particular the arrangement preferably provided coaxially to the connection element, enables a particularly precise detection of the rotational movement and / or position of the thread guide arm and also allows a particularly compact design of the thread storage unit.

[0025] According to a preferred embodiment, the work station is assigned a control system as described above and a sensor unit, also described above, which can be connected to the control system for exchanging information. The sensor unit is designed and arranged to detect the rotational movement and / or position of the thread guide arm and to transmit sensor information to the control system. The control system is preferably designed to evaluate and assess the transmitted sensor information and to control the drive unit in a defined manner based on the evaluation result. More preferably, the control system is designed to control the drive unit for regulating the thread tension and / or the amount of thread stored in the guided thread, and also, more preferably, to control the sensor unit for retrieving sensor information.

[0026] In a preferred embodiment, a rest position of the thread guide arm is provided in a position that crosses the thread path, in which the thread guided by the thread guide arm is pushed out of the thread path during its travel on the bobbin. In other words, the thread storage unit is arranged with the thread guide arm along the thread path such that a rest position of the thread guide arm, which corresponds to a zero position of the drive unit, lies outside the thread path and in the direction in which the thread guide arm pushes the thread out of the thread path. This ensures that the thread guide arm can be reset solely by the force exerted by the thread in the direction of the thread path when it is deflected out of the thread path.Alternatively or additionally, the thread storage unit can have further magnetically or mechanically spring-loaded coupling elements, which are oriented opposite to the magnetic force direction of the first and second coupling elements and are designed to return the thread guide arm as needed, in the opposite direction to the deflection caused by the first and second coupling elements. These further coupling elements can preferably be coupled, in the same way as the first and second coupling elements, to a drive unit and a control system coupled thereto, such as the control system described above, as well as to the sensor unit or another sensor unit, in order to pivot the thread guide arm as needed.

[0027] According to a further aspect of the present invention, a method for adjusting the thread tension of a running thread at a work location according to one of the embodiments described above is proposed. The sensor unit transmits sensor information about the rotational movement and / or position of the thread guide arm to a control system assigned to the work location. Based on the transmitted sensor information, the control system evaluates a magnetic force acting between the first and second coupling elements to identify the thread tension exerted on the thread and, in the event of a deviation deemed impermissible from a limit value or limit value range for the thread tension, controls the drive unit to change the position of the thread guide arm as described above. As described at the outset, the thread tension can be kept constant during the bobbin travel and regulated as required.

[0028] An embodiment of the invention is explained below with reference to the drawings. The drawings show: Fig. 1 a perspective schematic view of a thread storage unit according to an embodiment; Fig. 2 in a perspective schematic view an enlarged representation of a partial area of ​​the thread storage unit of Fig. 1 ; Fig. 3 in a perspective schematic view an enlarged representation of the thread storage unit of Fig. 1 without a thread guide arm, Fig. 4 in a perspective schematic representation of the thread guide arm of the thread storage unit of Fig. 1 , and Fig. 5 in a perspective schematic view shown in Fig. 1 The thread storage unit shown is arranged upstream of a paraffin treatment unit.

[0029] Figure 1Figure 1 shows a perspective schematic view of a thread storage unit 1 according to an embodiment, which is connected to a connecting plate 17 for arrangement at a work station, in particular a spinning or winding station, of a textile machine not shown here. Figures 2 to 4 show, in a perspective schematic view, an enlarged representation of a sub-area of ​​the in Figure 1 The thread storage unit 1 shown, as well as a perspective schematic representation of a thread guide arm 2 of this thread storage unit 1.

[0030] The thread storage unit 1 has a thread guide arm 2, which is arranged at the work location in the thread path F of a thread being wound onto a take-up spool, with a thread guide eyelet 13 located at its free end, the thread being guided through the thread guide eyelet 13. To form a thread storage unit, the thread guide arm 2 is pivotably mounted on a drive shaft 16 of an electric motor 5 of a drive unit 4 of the thread storage unit 1, wherein the thread guide arm 2 has a bushing 18 for arrangement at the free end of the drive shaft 16, so that the thread guide arm 2 is mounted on the drive shaft 16 without torque. The bushing 18 is further connected to a holder 9 connected to the thread guide arm 2, which has an opening for receiving a first coupling element 6 designed as a permanent magnet.

[0031] For the loop-forming pivoting of the thread guide arm 2 during operation, the drive shaft 16 of the electric motor 5 is connected to a coupling disk 14, which is arranged coaxially to the drive shaft 16, in a rotationally fixed manner. A carrier 8 is arranged on the coupling disk 14, which has a further bushing 12 for receiving another permanent magnet as a second coupling element 7. The permanent magnets on the thread guide arm 2 and the carrier 8 are aligned with each other such that they exert a mutually repulsive magnetic effect. A rotation of the coupling disk 14 by the reversing electric motor 5 thus causes a corresponding pivoting of the thread guide arm 2 about the drive shaft 16 without contact, which defines a pivot axis S, whereby the electric motor 5 is controlled via connection 19 by a control system (not shown here).

[0032] For position detection of the thread guide arm 2, a sensor unit 3 is arranged above - with reference to the graphic representation - the drive shaft 16 on a housing cover 11 of the housing 10, which with its sensor detecting the swivel angle is arranged coaxially to a connecting element 15 connected to the thread guide arm 2, which in turn extends in the longitudinal axis direction of the drive shaft 16.

[0033] The sensor unit 3 can reliably determine at least the rotational movement or the position of the thread guide arm 2. By transmitting corresponding sensor information to the control system, deviations of the thread guide arm 2 from the position set by the drive unit 4 can be detected. For example, if the thread tension increases, this causes the thread guide arm 2 to shift towards the second coupling element 7 against the spring force generated by the magnetic repulsion. Based on this, the control system can then shift the coupling disc 14 back. If, for example, the thread tension decreases due to thread sag, this causes the second coupling element 7 to shift towards the thread guide arm 2 by rotating the drive shaft 16 and the coupled carrier 8, including the coupling disc 14 and the permanent magnet.Due to the magnetic repulsion, the thread guide arm 2 moves in the same direction, thus pushing the guided thread away from its path or moving it further away from it, forming or enlarging a thread loop. In this way, a substantially constant thread tension can be achieved and maintained throughout the entire winding process or bobbin travel.

[0034] Figure 5Figure 1 shows a perspective schematic view of an embodiment of the arrangement of the yarn storage unit 1 at the work station (not shown), which can be a spinning or winding station. The yarn storage unit 1 is arranged upstream of a paraffin waxing unit 20, shown only schematically and in part, along a yarn path F, which runs from a yarn delivery device (not shown) towards a changing device (not shown). The paraffin waxing unit 20 has a support 22 below it, on which two yarn guide rollers 21 are rotatably mounted, over which the yarn can be guided along the yarn path in a partially wrapped manner.The thread storage unit 1 is positioned on the thread path F such that the thread guide arm 2, with its guide eye 13, can pivot into the thread path F to push the running thread out of its path F transversely to the direction of arrangement of the thread guide rollers 21. As a result of being pushed out of its path F by the thread storage unit 1, the thread comes into contact with the thread guide rollers 21, forming a thread loop of defined size between them. The size of the thread loop is varied as needed by the thread storage unit 1, depending on the detected rotational movement or position of the thread guide arm 2, via the control system that drives the electric motor 5 and consequently the thread guide arm 2. This allows the thread storage unit 1 to adjust and regulate the thread tension, which is advantageously kept constant during the bobbin winding process. Reference symbol list

[0035] 1 Thread storage unit 2 Thread guide arm 3 Sensor unit 4 Drive unit 5 Electric motor 6 First coupling element 7 Second coupling element 8 Carrier 9 Holder 10 Housing 11 Housing cover 12 Additional socket 13 Thread guide eyelet 14 Coupling disc 15 Connection element 16 Drive shaft 17 Connection plate 18 Socket 19 Connection 20 Paraffin device 21 Thread guide roller 22 Holder Thread path S-axis

Claims

1. A workstation of a textile machine, comprising a yarn delivery device for delivering a yarn, a traversing device for traversing the delivered yarn, and a yarn winding device for winding the traversed yarn onto a take-up package, which are arranged along a yarn path, and a yarn accumulator unit (1), which is arranged along the yarn path between the yarn delivery device and the traversing device to force the yarn running along the yarn path out of the yarn path in a defined manner by means of the pivoting movement of the yarn guide arm (2), wherein the yarn accumulator unit (1) comprises: - a yarn guide arm (2) pivotally mounted about a pivot axis (S), and - a controllable drive unit (4) for reciprocating pivoting of the yarn guide arm (2), characterised in that the yarn guide arm (2) is freely rotatably mounted and has a magnetically acting first coupling element (6) arranged at a distance from the pivot axis (S), and the drive unit has a second magnetic coupling element (7) which is arranged so as to be adjustable relative to the first coupling element (6), has a magnetically repulsive effect on the first coupling element (6), and is arranged so that it can be brought into active connection with the first coupling element (6) on the drive unit (4), whereby an adjustment of the second coupling element (7) in the direction of the first coupling element (6) causes a displacement of the first coupling element (6) in the same direction.

2. The workstation according to claim 1, characterised in that a rest position of the yarn guide arm (2) is provided in a position crossing the yarn path, in which the yarn guided by the yarn guide arm (2) is forced out of the yarn path during the package build.

3. The workstation according to claim 1 or 2, characterised in that the workstation is assigned a control system and a sensor unit (3) which can be connected to the control system for the exchange of information, wherein the sensor unit (3) is configured and arranged for detecting the rotary movement and / or position of the yarn guide arm (2) and for transmitting sensor information to the control system, and wherein the control system is configured to evaluate and assess the transmitted sensor information, and to control the drive unit (4) in a defined manner on the basis of the assessment result.

4. The workstation according to claim 3, characterised in that the control system is configured to control the drive unit (4) for regulating the yarn tension and / or the stored quantity of the guided yarn.

5. The workstation according to one or more of the preceding claims, characterised in that the first coupling element (6) is detachably attached to the yarn guide arm (2).

6. The workstation according to one or more of the preceding claims, characterised in that the second coupling element (7) is arranged on a carrier (8) which can be adjusted by means of the drive unit (4) coaxially about the pivot axis (S) of the yarn guide arm (2).

7. The workstation according to claim 6, characterised in that the drive unit (4) has an electric motor (5) with a drive shaft (16) which is connected to the carrier (8) in a torsionally rigid manner and on which the yarn guide arm (2) is freely rotatably mounted.

8. The workstation according to claim 7, characterised in that the carrier (8) is arranged on a coupling disc (14) which is arranged coaxially with the drive shaft (16) and is connected to the drive shaft (16) in a torsionally rigid manner.

9. The workstation according to one or more of the preceding claims, characterised in that the first coupling element (6) and the second coupling element (7) are configured as permanent magnets.

10. The workstation according to one or more of the preceding claims, characterised in that the yarn accumulator unit (1) is assigned a sensor unit (3) which is configured and arranged to detect the rotary movement and / or position of a connection element (15) which is connected in a torsionally rigid manner to the yarn guide arm (2) and is arranged in particular coaxially with respect to the drive shaft (16).

11. A method for adjusting a yarn tension of a running yarn at a workstation according to any one of claims 3 or 4, wherein the sensor unit (3) transmits sensor information about the rotary movement and / or position of the yarn guide arm (2) to a control system assigned to the workstation, based on the transmitted sensor information, the control system evaluates a magnetic force acting between the first (6) and second coupling element (7) to identify a prevailing yarn tension and, in the event of a deviation from a limit value or limit value range for the yarn tension that is determined to be impermissible, controls the drive unit (4) in a defined manner to change the position of the yarn guide arm (2).