EP3401423A1 - Method for pressing a pressure roller on a draw-off roller and draw-off device - Google Patents

Abstract

In a method for pressing a pressure roller (10) on a take-off roll (9) of a workstation (2) of a textile machine, the pressure roller (10) by means of an actuating device (11) of the workstation (2) from a working position, in which it to the take-off roll (9) is pressed into a piecing position (II), in which it is lifted from the take-off roll (9), and back to be transferred. The pressure roller (10) is pressed in its working position by a prestressed spring element (12) to the take-off roll (9). A take-off device (3) for a workstation (2) of a textile machine (1) has a take-off roll (9) and a pressure roll (10) which can be pressed against the take-off roll (9) and an actuating device (11). By means of the actuating device (11), the pressure roller (10) from a working position in which it is pressed against the take-off roll (9), in a piecing position (II), in which it is lifted from the take-off roll (9), and transferred back , The withdrawal device (3) has a prestressable spring element (12) for pressing the pressure roller (10) against the take-off roll (9).

Description

The present invention relates to a method for pressing a pressure roller to a take-off roll of a workstation of a textile machine. The pressure roller is by means of an actuator of the work from a working position in which it is pressed against the take-off roll, in a piecing position in which it is lifted from the take-off roll, and back to be transferred. Furthermore, the invention relates to a corresponding extraction device for a job of a textile machine.

Withdrawal devices with a drivable take-off roll and a pressure roll which can be pressed against the take-off roll have become known in various designs in the prior art. For example, it is known in open-end spinning machines, which are operated by means of a movable along the spinning machine maintenance device, to press the pressure roller by means of spring force to the take-off roll. To lift the pressure roller from the take-off roller during piecing a lever is present, which can be manually operated by the maintenance device or an operator against the spring force. The resetting of the pressure roller takes place by the spring force after the maintenance device or the operator releases the corresponding lever again. Such a spinning machine is for example in the DE 199 23 047 A1 shown.

Furthermore, from the DE 44 31 537 C2 a spinning machine has become known in which the pressure roller is pressed in operation by means of an electromagnet with a push rod to the take-off roll and is lifted from this. This makes it possible to change and adjust the contact pressure. Such a workstation-specific actuator for lifting and returning the pressure roller is particularly advantageous for textile machines with single-user automation.

The DE 10 2007 024 588 A1 also describes a workstation-specific actuator in which according to one embodiment, the pressure roller can also be lifted and reset by means of a double-acting actuator such as a pneumatic cylinder. The pressing of the pressure roller to the take-off roll during the normal spinning operation is also carried out by the pneumatic cylinder. The contact pressure can be changed by the height of the air pressure.

Object of the present invention is to propose a trigger device and a method for pressing a pressure roller, which allow a reliable contact pressure of the pressure roller to the take-off roll.

The object is solved with the features of the independent claims.

In a method for pressing a pressure roller to a take-off roll of a workstation of a textile machine, the pressure roller by means of an actuator of the work from a working position in which it is pressed against the take-off roll, in a piecing position in which it is lifted from the take-off roll, and back transferred. A corresponding extraction device has a take-off roll and a pressure roll which can be pressed against the take-off roll. Furthermore, the trigger device has an actuating device, by means of which the pressure roller from the working position in the Anspinnposition and back is transferable.

It is now provided that the pressure roller is pressed in its working position by a biased spring element to the take-off roller. The trigger device has for this purpose a prestressable spring element. The fact that now during operation, the pressing of the pressure roller to the take-off roll is not by means of the actuator, but by means of a biased spring element, it is not necessary, the actuator during operation constantly with compressed air or electricity apply. It is thus possible even with a machine with single-station automation, in which an operating device must be provided at each workstation, the exhaust devices energy-saving. The lifting of the pressure roller from its working position into its Anspinnposition takes place as well as the return to the working position by means of the actuator. The return of the pressure roller in the working position can therefore be done very gently and without harmful effects on the thread. By the combination of the actuating device and the additional spring element, a particularly reliable contact pressure of the pressure roller to the take-off roller can be achieved.

It is particularly advantageous if the pressure roller is pressed in its working position only by the prestressed spring element, as a result of a particularly energy-saving operation is possible. In addition, it is thereby possible to adjust the spring element so that an always constant contact pressure is achieved even over a longer period of operation.

According to a particularly advantageous embodiment, the spring element is acted upon by the actuating device with a bias voltage. In the case of the extraction device, the spring element is in operative connection with the actuating device for this purpose. This makes it possible to selectively bias the spring element by means of the actuating device with a bias of a certain size and thereby selectively generate a defined high contact pressure of the pressure roller on the take-off roll. Since the contact pressure corresponds exactly to the biasing force of the spring and is proportional to this, a uniform contact pressure can be generated even when the pressure roller or the take-off roll wear, so that the thread take-off always takes place under the same conditions. Likewise, this can also be created at several jobs of a textile machine largely the same deduction conditions.

It is particularly advantageous if the pretension or a setting parameter of the actuating device representing the preload is predetermined, so that the magnitude of the preload can also be adapted to different spinning conditions or different yarn counts and the like. In this case, a setting parameter of the actuating device representing the preload can, for example, be the path of an element of the actuating device, the air pressure in the case of a pneumatic actuation and the like.

In the method, it is also advantageous if the transfer of the pressure roller from the piecing position into the working position takes place in two phases. In a first phase while the pressure roller is brought by the actuator in abutment with the take-off roll. In the second phase, the spring element is then brought into operative connection with the actuating device and subjected to the bias. This makes it possible to set the predetermined bias exactly, since the spring is set only upon reaching a contact between the take-off roller and the pressure roller under bias. In the case of the draw-off device, in this case the operative connection between the actuating device and the spring element can be released.

In addition, it is advantageous if the actuating device comprises an electric motor, in particular a stepping motor, in particular a linear stepping motor, which is moved away in the second phase. Due to the path-controlled method of the electric motor, it is possible to achieve the desired bias of the spring particularly precisely, since this is directly proportional to the travel or the travel of the electric motor. The electric motor is used in this case equally for lifting and returning the pressure roller and for biasing the spring element.

If the actuating device includes an electric motor, it is furthermore advantageous if the adjustment parameter representing the preload a travel of the electric motor, in particular a number of steps of the stepping motor, is. The desired size of the bias voltage can be set and achieved with a stepper motor in a particularly accurate manner.

It is also advantageous if it is detected by the trigger device, whether the pressure roller rests against the take-off roll and / or whether the spring element is in operative connection with the actuating device. The beginning of the second phase of the path-controlled method or the biasing of the spring element can thereby be determined exactly. For this purpose, the withdrawal device has a corresponding detection device. It is particularly advantageous that even with wear of the pressure roller and / or the take-off roller without further adjustments to the device always the same desired biasing force is achieved because the biasing of the spring element begins only when the pressure roller is applied to the take-off roll. Because of this, the contact pressure of the pressure roller is independent of the diameter, so that even after a grinding of the pressure roller without adjustments nor the desired contact pressure is achieved.

In order to produce the releasable operative connection between the spring element and the actuating device, in particular the electric motor, it is advantageous if the spring element is arranged tensionably in a sleeve which is provided between a lifting element of the electric motor and an actuating lever of the pressure roller. The spring element is preferably designed as a spiral spring, but other embodiments would also be possible. Under the lifting element of the electric motor is understood in the context of the present invention, the element which performs an axial movement for biasing the spring element. It may, for example, be a transmission element connected to the electric motor, such as a connecting rod, a toothed rack, a threaded spindle or the like or, in the case of a linear motor, the rotor.

It is particularly advantageous if the sleeve relative to its axial direction is slidably connected to the lifting element and fixed to the operating lever. In this case, the displaceability between the sleeve and the lifting element in the first phase allows the transfer of the pressure roller from its Anspinnposition to the working position and then by compressing the spring element in the sleeve in the second phase, the application of the bias on the spring element. Of course, it would also be possible to firmly connect the sleeve with the lifting element and slidably with the actuating lever.

Figur 1

eine schematische Schnittdarstellung einer Arbeitsstelle einer Textilmaschine in einer Übersichtsdarstellung,

Figur 2

eine schematische, teilgeschnittene Darstellung einer Abzugsvorrichtung, bei welcher die Druckwalze sich in der Anspinnposition befindet,

Figur 3

eine schematische, teilgeschnittene Darstellung der Abzugsvorrichtung der Figur 1, bei welcher sich die Druckwalze in der Arbeitsposition befindet, sowie

Figur 4

eine schematische, teilgeschnittene Darstellung der Abzugsvorrichtung der Figur 1, bei welcher die Druckwalze an die Abzugswalze angepresst wird.

Further advantages of the invention will be described with reference to the following embodiments. Show it:

FIG. 1

a schematic sectional view of a workstation of a textile machine in an overview,

FIG. 2

a schematic, partially sectioned view of a take-off device, wherein the pressure roller is in the piecing position,

FIG. 3

a schematic, partially sectioned view of the trigger device of FIG. 1 in which the pressure roller is in the working position, as well

FIG. 4

a schematic, partially sectioned view of the trigger device of FIG. 1 , in which the pressure roller is pressed against the take-off roll.

FIG. 1 shows an overview of a workstation 2 a textile machine 1 in a schematic sectional view. The textile machine 1 is presently designed as a spinning machine and has in the usual way a spinning element 8, here a spinning rotor, on which a fiber material 7 is supplied becomes. In the spinning element 8, the fiber material 7 is spun into a thread 4 and withdrawn by means of a take-off device 3. After the take-off device 3, the thread 4 optionally passes through further elements, such as a quality sensor or a paraffining device, and is finally wound onto a bobbin 6 by means of a winding device 5.

The take-off device 3 includes in a conventional manner a fixedly mounted, driven with a withdrawal roller speed take-off roller 9, and a can be pressed against the take-off roller 9 and lifted off the take-off roller 9 pressure roller 10. To lift the pressure roller 10 from the take-off roller 9 is an actuator 11th provided, which is shown here only schematically. In this case, the pressure roller 10 is shown in its working position I in solid lines, while the Anspinnposition II is indicated in dashed lines, in which the pressure roller 10 is lifted from the take-off roller 9. In such exhaust devices 3, it is often desirable to adjust the contact pressure of the pressure roller 10 to the take-off roll 9 adjustable to allow adaptation to conditions of the job 2 such as the production of different yarn numbers.

FIG. 2 shows a partially cut, schematic representation of such a take-off device 3 with a take-off roller 9 and a pressure roller 10. The pressure roller 10 can be lifted by means of an actuator 11 of the take-off roller 9. In FIG. 2 In this case, the pressure roller 10 is shown in its raised by the take-off roller 9 Anspinnposition II. The actuating device 11 is presently embodied as an electric motor 13 and mounted on the workstation 2, which is shown here only schematically and broken off, the textile machine 1 (not shown here). The electric motor has a lifting element 15, which performs a lifting movement in the direction of the double arrow when the electric motor 13 is actuated. The lifting element 15 is connected to an actuating lever 16 which is rotatably mounted about a pivot point 17, and actuated via this the pressure roller 10, that is transferred you from working position I (see Fig. 3 ) in the Anspinnposition II and back.

In the present case, the actuating lever 16 is designed as a two-armed lever, wherein the pressure roller 10 is mounted on a first lever arm and the second lever arm is connected to the electric motor 13 of the actuating device 11. Of course, it would also be conceivable to carry out the actuating lever 16 as a one-armed lever.

The lifting element 15 is connected to a spring plate 18, which is arranged displaceably in a sleeve 14. The sleeve 14 is in turn fixed, according to the present example but rotatably connected to the actuating lever 16. Likewise, according to the present illustration, the electric motor 13 is fixed, but pivotally connected to the textile machine 1 or the workstation 2, to allow the resultant by the lifting movement of the lifting element 15 changes in position of the individual components. Of course, other types of bearings or connections between the motor 13, the sleeve 14 and the operating lever 16, which allow such changes in position, possible.

As can be seen now by the partially sectional view of the sleeve 14, is supported on the sleeve 14, a spring element 12, here in the form of a coil spring, which is acted upon by the spring plate 18 and the lifting element 15 of the electric motor 13 with a bias. The sleeve 14 is relative to its axial direction, which in the present case corresponds to the direction of the double arrow and is determined by the central longitudinal axis of the cylindrical body of the sleeve 14, slidably connected via the spring plate 18 with the lifting element 15.

In the Anspinnposition II shown in the present case of the pressure roller 10, the lifting element 15 is in an extended position, in which the The spring element 18 connected to the lifting element 15 has a first distance to the electric motor 13.

The transfer of the pressure roller 10 from its Anspinnposition II back to its working position I will now be based on the FIG. 3 described, in which the pressure roller is shown in the working position I. For the transfer of the pressure roller 10 in its working position I, the electric motor 13 is moved, so that the lifting element 15 and the associated spring plate 18 to move in the direction of the electric motor 13. This movement is transmitted via the spring element 12 and the sleeve 14 on the actuating lever 16, wherein the pressure roller 10 is brought into abutment with the take-off roller 9. The lifting element 15 is now in a retracted position, in which the spring plate 18 connected to the lifting element 15 has a second distance to the electric motor 13, which is smaller than the first distance. It is detected by the trigger device 3 when the pressure roller 10 has reached the surface of the take-off roller 9. For this purpose, the withdrawal device has a corresponding detection device. The detection device can be formed for example by a proximity switch, a contact switch or by elements of the actuator.

After the pressure roller 10 has been brought into abutment with the take-off roller 9, the first phase of the transfer of the pressure roller is in the working position I finished. As soon as the concerns of the pressure roller 10 is detected on the take-off roller 9, the spring element 12 is biased in the second phase.

The application of the spring element 12 with the bias is in FIG. 4 shown. Again FIG. 4 removed, now forms the take-off roller 9 a stop for the pressure roller 10, so that at this point no further feed movement is possible. Another method of the electric motor 13 and the lifting element 15 is now only against the Restoring force of the spring element 12 possible. Thus, by the abutment of the pressure roller 10 on the take-off roll 9, the operative connection between the spring element 12 and the actuating device 11, in particular the electric motor 13 of the actuator 11, produced. As a result, a bias voltage can now be applied to the spring element 12 in a further method of the electric motor 13 or the lifting element 15. Since the electric motor 13 is moved away in this second phase, the travel of the lifting element 15 and thus the bias of the spring element 12, which is proportional to the travel of the lifting element 15, can be set very accurately.

Due to the combination of the actuating device 11 for lifting and returning the pressure roller 10 with a spring element which can be acted upon with a specific bias, it is possible to precisely set the desired contact force of the pressure roller 10 at a workstation 2. It is particularly advantageous in this case that the withdrawal device 3 shown makes it possible to adjust the contact pressure force separately at each workstation 2 of the textile machine 1, so that even a multiple-part occupancy of the textile machine 1 is possible without problems. It is also possible to take account of conditions at the individual jobs 2. For example, it is not necessary to make readjustments when the take-off roll 9 or the pressure roller 10 is worn, since the start of the second phase with the path-controlled process of the electric motor 13 is independent of a wear state of the rolls 9, 10. Since the contact force of the pressure roller 10 depends on the take-off roll 9 only by the bias of the spring element 12 or the predetermined path of the electric motor 13 by the described extraction device 3, it is also possible in a particularly favorable manner to set reproducible conditions at each job 2 that is, the same contact pressure on the pressure roller 10 acts both at the same workstation 2 and at different workstations 2 of a textile machine 1. The yarn production can be done with a very high quality.

The present invention is not limited to the illustrated and described embodiments. Variations within the scope of the claims are also possible as a combination of features, even if they are shown and described in different embodiments.

LIST OF REFERENCE NUMBERS

1

textile machine

2

place of work

3

off device

4

thread

5

spooling device

6

Kitchen sink

7

fiber material

8th

spinning element

9

off roll

10

platen

11

actuator

12

spring element

13

electric motor

14

shell

15

lifting

16

actuating lever

17

Fulcrum of the operating lever

18

spring plate

I

working position

II

piecing

Claims (13)

Method for pressing a pressure roller (10) against a take-off roller (9) of a workstation (2) of a textile machine (1), wherein the pressure roller (10) is moved by means of an actuating device (11) of the workstation (2) from a working position (I) to which it is pressed against the take-off roll (9), into a piecing position (II) in which it is lifted off the take-off roll (9) and can be returned, characterized in that the pressure roll (10) in its working position (I) is pressed by a prestressed spring element (12) to the take-off roll (9). Method according to the preceding claim, characterized in that the spring element (12) by the actuator (11) supplied with a bias voltage, whereby preferably the size of the bias voltage or a bias voltage representing setting parameters of the actuator (11) is predetermined. Method according to one of the preceding claims, characterized in that the transfer of the pressure roller (10) from the piecing position (II) in the working position (I) takes place in two phases, wherein in a first phase, the pressure roller (10) by the actuating device (11 ) is brought into abutment with the take-off roll (9) and brought in a second phase, the spring element (12) into operative connection with the actuating device (11) and is acted upon by the bias. Method according to the preceding claim, characterized in that the actuating device (11) comprises an electric motor (13), in particular a stepping motor, in particular a linear stepping motor, which is moved away in the second phase. Method according to the preceding claim, characterized in that the adjustment parameter representing the bias voltage is a travel path of the electric motor (13), in particular a step number of the stepping motor. A method according to any one of claims 3-5, characterized in that it is detected whether the printing roller (10) against the pick roller (9) is present and / or whether the spring element (12) to the actuating device (11) is in operative connection. Deduction device (3) for a workstation (2) of a textile machine (1), in particular for carrying out the method according to one of the preceding claims, with a take-off roll (9) and a pressure roll (10) which can be pressed against the take-off roll (9) and with an actuating device (11), by means of which the pressure roller (10) from a working position (I), in which it is pressed against the take-off roll (9), in a piecing position (II), in which it is lifted from the take-off roll (9), and has back transferable, characterized in that the withdrawal device (3) has a prestressable spring element (12) for pressing the pressure roller (10) to the take-off roll (9). Withdrawal device (3) according to the preceding claim, characterized in that the spring element (12) is in operative connection with the actuating device (11) and can be acted on by the actuating device (11) with a preferably presettable bias. Deduction device (3) according to the previous device claim, characterized in that the operative connection is releasable. Deduction device (3) according to one of the preceding device claims, characterized in that the actuating device (11) comprises an electric motor (13), in particular a stepping motor, in particular a linear stepping motor. Withdrawal device (3) according to one of the preceding device claims, characterized in that the withdrawal device (3) has a detection device by means of which it is possible to detect whether the pressure roller (10) bears against the take-off roll (9) and / or whether the spring element (12) is in operative connection with the actuating device (11). Deduction device (3) according to one of the preceding device claims, characterized in that the spring element (12) is arranged clampable in a sleeve (14) which between a lifting element (15) of the electric motor (13) and an actuating lever (16) of the pressure roller ( 10) is provided. Deduction device according to one of the preceding device claims, characterized in that the sleeve (14) relative to its axial direction slidably connected to the lifting element (15) and fixed to the actuating lever (16).

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