MEASURING DEVICE FOR SPINNING CYLINDERS

Description

[0001] The invention relates to a measuring device for measuring the diameter of spinning cylinders of an upper roller of fiber processing machines.

[0002] Spinning cylinders are typically mounted in pairs, rotatably on an axle pin, to an upper roller. Drafting units are used in various fiber processing machines, such as drawing, flyer, ring spinning, and air-jet spinning machines, to stretch fiber slivers. These drafting units consist of several pairs of rollers arranged in series and operating at different speeds. The fiber sliver passing between the roller pairs is subjected to distortion. The roller pairs comprise a lower roller and an upper roller, the lower roller usually being a steel roller, while the upper roller is equipped with spinning cylinders that have an elastic covering. During operation, the covering wears down due to the passing fiber slivers, causing it to lose its cylindrical shape and compromising its proper interaction with the corresponding lower roller.Therefore, the spinning cylinders, or rather their covers, must be ground periodically. During this grinding process, the top layer of the cover is removed, restoring the original shape of the cover, for example, its cylindrical form.

[0003] JP 2000 018923 A shows a test device for the deformation and outer diameter of a roller or the like with a laser beam measuring device.

[0004] WO 99 / 13292 A1 describes a measuring device with a holder that allows a measuring object to be held in a position within a central plane defined by a guide. A carriage allows the measuring object to be moved into the area of ​​a focused energy beam.

[0005] Further approaches to measuring and grinding spinning cylinders are known from the specialist publication «Grinding of spinning cylinder covers» (Melliand Textilberichte, Deutscher Fachverlag, Frankfurt am Main, DE, Vol. 7 4, No. 6, June 1, 1993, pages 493-495).

[0006] To enable an automated grinding process tailored to the current geometric dimensions of the spinning cylinders to be ground, the diameter of the spinning cylinders must be determined before grinding. According to current technology, it is assumed that the spinning cylinders used in a machine are subject to approximately the same level of wear. Therefore, the diameter of a spinning cylinder from this machine is measured manually, and subsequently, a necessary grinding depth, or a diameter to be achieved by the grinding process, is determined. Taking into account the uncertainties arising from the measurement and the machine's operation, the target diameter is set, ensuring a flawless result for all spinning cylinders in the machine.The disadvantage of this is that an excessive grinding depth is set, resulting in the spinning cylinders being ground to a diameter that would be unnecessary if considered individually. Since such regrinding is performed several times during the life cycle of the spinning cylinders, an excessive grinding depth leads to a reduction in their service life.

[0007] The object of the invention is therefore to propose a device for measuring the diameter of spinning cylinders, which enables automatic measurement with high accuracy.

[0008] The problem is solved by a measuring device with the features of the independent claim. To solve the problem, a measuring device for measuring the diameter of spinning cylinders arranged in pairs on an axle pin of an upper roll of fiber processing machines is proposed. The measuring device comprises a laser barrier, a holder for supporting the upper rolls, a displacement measuring device, and a linear drive for moving the upper rolls with the holder. The holder has a recess for receiving the axle pin of the upper roll. A simple recess, for example in the form of a triangle, holds the axle pin of the upper roll, and thus also the spinning cylinders, in a defined position relative to the laser barrier. As an alternative to a recess in the holder for receiving and positioning the upper roll, it may be advantageous to provide a clamping device for fixing the upper roll to the holder.Precise positioning of the upper roller at a specific height is not necessary, as the spinning cylinders interrupt the laser barrier with their outer circumference, thus making the exact position of the axle bolt or axis irrelevant.

[0009] The linear drive moves the holder, or rather the upper roller and spinning cylinders it contains, past the laser barrier. The laser barrier is positioned so that it is interrupted by the movement of the spinning cylinder. The diameter of the spinning cylinders is thus determined by the movement of the holder and linear drive through the laser barrier. As soon as the spinning cylinder has passed the laser barrier, it closes again. The distance traveled by the holder during the time the laser barrier is interrupted corresponds to the diameter of the spinning cylinder. This distance is then measured by the integrated displacement measurement system. The laser barrier, linear drive, and displacement measurement system are all fixed in a fixture frame. Advantageously, the holder is equipped with sliding bearings, which also support it within the fixture frame.The holder is moved on the slide bearings by the linear drive. The use of slide bearings results in high repeatability and smooth movement of the holder.

[0010] As an alternative to moving the upper rollers with the holder, a displacement of the laser barrier along the holder is proposed. Instead of the holder, the laser barrier is moved by the linear drive, and its displacement is determined by measuring the position. The laser barrier can be guided on sliding bearings within the fixture frame.

[0011] In an alternative embodiment to the design with plain bearings, the holder or laser barrier is mounted on a sliding carriage, which is connected to the linear drive. The sliding carriage stabilizes the components mounted on it, such as the laser barrier or holder with its upper roller. Using a sliding carriage allows for mounting on guided rollers, for example, which reduces friction compared to plain bearings.

[0012] Preferably, the linear drive comprises a rotary drive and a spindle, wherein the sliding carriage is connected to the spindle via a ball screw nut in a backlash-free manner and is held on sliding bearings. The sliding bearings can be guided on rails or, preferably, on bearing rods. Bearing rods have the advantage that they can be enclosed by the sliding bearings, thus resulting in virtually backlash-free guidance of the sliding carriage. Designing the linear drive as a rotary drive with a spindle has the advantage that a backlash-free transmission of the drive's rotation to the spindle is possible. The conversion of the spindle's rotary motion into a linear motion of the sliding carriage is achieved via the ball screw nut, which is attached to the sliding carriage. Ball screw nuts are known from the prior art and are widely used in precision drives due to their backlash-free operation.

[0013] It is advantageous to integrate the position measurement into the rotary drive. High accuracy is achieved, for example, by using incremental encoders. This ensures high resolution of the position measurement and prevents contamination of the measurement unit. Since position measurement only needs to be active during the interruption of the laser barrier, measuring the distance traveled by the sliding carriage is sufficient.

[0014] Advantageously, a measuring speed and a working speed are provided for the movement of the holder or the displacement of the laser barrier, with the working speed being a multiple of the measuring speed. If only one of the possible end positions of the sliding carriage or holder is provided for loading and unloading the measuring device with the spinning cylinders, it is advantageous to return to a starting position as quickly as possible after a measurement. However, if the spinning cylinders are inserted into the measuring device in both end positions of the sliding carriage or holder, a measurement in both directions of movement is possible, and thus a working speed is not necessary.

[0015] It has been shown that a high degree of precision in the movement of the upper rollers or spinning cylinders can be achieved with a measuring speed of 5 mm to 20 mm per second. This largely prevents wobbling or vibration of the measuring device and thus of the device frame, resulting in high accuracy in the diameter measurement. Preferably, the diameter of the spinning cylinders can be determined with an accuracy of at least 0.02 mm. This measurement allows for a specification of the spinning cylinder diameter with a maximum tolerance of plus or minus 0.02 mm. Knowing the exact diameter of the spinning cylinders enables grinding of the individual spinning cylinders with the shallowest possible grinding depth, without the need to include safety margins when specifying the grinding depth.This allows the spinning cylinders to be machined with a shallower grinding depth and, consequently, to be ground more frequently before reaching their minimum diameter required for operation. This results in a longer service life for the spinning cylinders and thus a corresponding reduction in the operating costs of the fiber processing machine.

[0016] Furthermore, a method for measuring the diameter of spinning cylinders arranged in pairs on an axle bolt of an upper roll of fiber processing machines is proposed using a measuring device as described above. The laser barrier is interrupted when the upper roll moves or when the laser barrier is displaced by the spinning cylinder, and this interruption triggers the activation and deactivation of the displacement measurement. Thus, the distance traveled by the holder or the laser barrier during the interruption of the laser barrier corresponds to the current diameter of the spinning cylinder. In a further development of the method, two independent laser barriers are used for an upper roll to measure the two spinning cylinders of an upper roll separately. The displacement measurement is activated independently of each other by the two laser barriers.Determining the diameters of the spinning cylinders in this way makes it possible to sort out and discard upper rollers whose spinning cylinders differ significantly in diameter.

[0017] Also proposed is a grinding machine for grinding spinning cylinders arranged in pairs on an axle bolt of an upper roller of fiber processing machines. This machine comprises a feed magazine, a discharge magazine, a processing module, and a control unit. The processing module includes a grinding device with a grinding wheel and a measuring device, as described above, for determining the diameter of the spinning cylinders before the grinding process. The measuring device measures the current diameters of the spinning cylinders before grinding. By measuring the diameters, the upper rollers, or rather their spinning cylinders, can be ground individually. Without the measuring device, all spinning cylinders would be ground to a fixed standard diameter, even if this were not necessary for all upper rollers or would result in insufficient material removal from a worn surface.In one operating mode, knowing the current diameter of a spinning cylinder to be ground allows the grinding wheel to be positioned precisely against the cylinder, ensuring the largest possible diameter is maintained after grinding. This significantly extends the service life of individual top rollers. Furthermore, it is unnecessary to grind top rollers with the same service life simultaneously, as the grinding depth required for renewing the surface of each spinning cylinder is individually set for each roller as it enters the grinding position. In another operating mode, the spinning cylinders are ground to a predetermined target diameter. Knowing the current diameter of each cylinder allows for verification that the grinding process achieves a specified grinding depth.

[0018] Preferably, the linear drive and the displacement measurement are evaluated and controlled by the grinding machine's control system. This eliminates the need for a separate control system for the measuring device and allows the measured diameter of a spinning cylinder to be assigned to the upper roller undergoing the grinding process without referencing via an interface. Furthermore, if the measuring device is integrated into the grinding machine, a separate fixture frame can be omitted, and the measuring device can be incorporated into the machine frame.

[0019] The invention will now be explained using an exemplary embodiment and further illustrated by the drawing. Figure 1 shows a schematic representation of a top roller according to the prior art; Figure 2 shows a schematic representation of a first embodiment of a measuring device; Figure 3 shows a schematic representation of a view in direction X according to the Figure 2 Figure 4 shows a schematic representation of a second embodiment of a measuring device; Figure 5 shows a schematic representation of a cross-section at location YY of the Figure 4 Figure 6 shows a schematic representation of a third embodiment of a measuring device and Figure 7 shows a schematic representation of an embodiment of a grinding machine.

[0020] Figure 1Figure 1 shows a schematic representation of a prior art upper roller 3 with two spinning cylinders 4. The upper roller 3 has an axle pin 5 with an axis 6, at each end of which a spinning cylinder 4 is held. The spinning cylinders 4 are rotatably mounted on the axle pin 5 and fixed in position along the axis 6. Each spinning cylinder has a sleeve 7 and a covering 8 applied to the sleeve 7.

[0021] Figure 2 shows in schematic representation a first embodiment of a measuring device 14 and Figure 3 schematic representation of a view in direction X after the Figure 2A laser barrier 25 and a linear drive 31 are fixedly mounted in a fixture frame 24 of the measuring device 14. A displacement measurement device 27 is provided in the linear drive 31. The linear drive 31 is connected to a holder 28. The holder 28 is movably supported on the fixture frame 24 by means of sliding bearings 32. The holder 24 also has a recess 29 in which an upper roller 3, or rather its axle pin 5, is inserted. The spinning cylinder 4, held on the axle pin 6, is moved by the linear drive 31 through the laser barrier 25 with a movement 30. The laser barrier 25 is arranged such that the spinning cylinder 4 interrupts the laser barrier 25 during the movement 30. A distance traveled during the interruption of the laser barrier 25 is recorded by the path measurement 27 and thus a diameter 9 of the spinning cylinder 4 is determined.

[0022] Figure 4shows in schematic representation a second embodiment of a measuring device 14 and Figure 5 schematic representation of a cross-section at point YY of the Figure 4A laser barrier 25 and a linear drive are fixedly mounted in a fixture frame 24 of the measuring device 14. The linear drive is designed as a rotary drive 34 and includes a displacement measurement unit 27 and a spindle 35. The laser barrier 25 is fixedly mounted on two bearing rods 40, which are fixedly attached to the fixture frame 24 via two bearings 39. A sliding carriage 33 is mounted on the bearing rods 40 on sliding bearings 38. The spindle 35 passes through a ball screw nut 37 attached to the sliding carriage 33. By rotating 36 the spindle 35, the ball screw nut 37, and thus the sliding carriage 33 with the sliding bearings 38 on the bearing rods 40, performs the linear movement 30 relative to the laser barrier 25. A holder 28 is attached to the sliding plate 33. The holder 24 has a recess 29 in which an upper roller 3, or its axle bolt 5, is inserted.The spinning cylinder 4, held on the axle bolt 6, is moved by the rotary drive 34 through the laser barrier 25 with the holder 28 and the sliding plate 33 by the movement 30. The laser barrier 25 is arranged such that it is interrupted by the spinning cylinder 4 during the movement 30. The distance traveled during the interruption of the laser barrier 25 is recorded by the displacement sensor 27, and thus a diameter 9 of the spinning cylinder 4 is determined.

[0023] Figure 6Figure 1 schematically shows a third embodiment of a measuring device 14. A laser barrier 25 and a linear drive are fixedly mounted in a fixture frame 24 of the measuring device 14. The linear drive is designed as a rotary drive 34 and includes a displacement sensor 27 and a spindle 35. The holder 28 is also fixedly mounted on the fixture frame 24. Bearing rods 40 are fixedly mounted on the fixture frame 24 via bearings 39. A ball screw nut 37 is slidably mounted on the bearing rods 40. A laser barrier 25 is attached to the ball screw nut 37. The spindle 35 is rotatably mounted in the bearings 39 and passes through the ball screw nut 37. By rotating 36 the spindle 35, the ball screw nut 37, and thus the laser barrier 25, performs a linear displacement 26 on the bearing rods 40 relative to the holder 28.The holder 24 has a recess 29 in which an upper roller 3, or rather its axle pin 5, is inserted. The laser barrier 25 is moved past the spinning cylinder 4 by the rotary drive 34 and the spindle 35 with a displacement 26. The laser barrier 25 is arranged such that it is interrupted by the spinning cylinder 4 during the displacement 26. The distance traveled during the interruption of the laser barrier 25 is recorded by the displacement sensor 27, and thus the diameter of the spinning cylinder 4 is determined.

[0024] Figure 7Figure 1 shows a schematic representation of an embodiment of a grinding machine 1 with a measuring device 14. The grinding machine 1 includes, by way of example, a feed magazine 10, a machining module 12, and a discharge magazine 13. The grinding machine 1 is mounted on a foundation 2 with the machining module 12, and the feed magazine 10 and the discharge magazine 13 are attached to the machining module 12. The feed magazine 10 holds upper rollers 3 to be ground in several tiers. The machining module 12 is shown in an exemplary embodiment with a turret 17 mounted on a rotary axis 18. The turret 17 serves to receive and transport the upper rollers 3 through the machining module 12. Furthermore, the machining module 12 includes a control unit 42 and a grinding device 15 with a grinding wheel 16.From the individual levels of the feed magazine 10, the upper rollers 3 are moved by a lifting device 11 to the measuring device 14 and then to a transfer guide 22. The upper rollers 3 pass through the measuring device 14, where the diameter of the spinning cylinders of the upper rollers 3 is measured. Via the transfer guide 22, the upper rollers 3 reach a transfer position 19. In the transfer position 19, the upper roller 3 is taken over by the turret 17. The turret 17 is rotated by 120 degrees, and the transferred upper roller 3 reaches the grinding position 20. According to the measured diameter of the spinning cylinder, the control 42 adjusts the feed of the grinding wheel 16, and the spinning cylinder is ground. After a further rotation of the turret 17 by 120 degrees, the upper roller 3 reaches a discharge position 21.In discharge position 21, the upper roller 3 is released from the turret 17 and reaches the discharge magazine 13 via a discharge guide 23. The discharge magazine 13 is shown as an example of a rectangular magazine in the illustrated design.

[0025] The present invention is not limited to the embodiments shown and described. Modifications within the scope of the claims are possible, as is a combination of the features, even if these are shown and described in different embodiments. legend

[0026] 1 Grinding machine 2 Foundation 3 Top roller 4 Spinning cylinder 5 Axle bolt 6 Axle 7 Sleeve 8 Cover 9 Diameter of spinning cylinder 10 Feed magazine 11 Lifting device 12 Machining module 13 Output magazine 14 Measuring device 15 Grinding device 16 Grinding wheel 17 Turret 18 Rotary axis 19 Pick-up position 20 Grinding position 21 Output position 22 Transfer guide 23 Output guide 24 Fixture frame 25 Laser barrier 26 Laser barrier movement 27 Position measurement 28 Holder 29 Recess 30 Holder movement 31 Linear drive 32 Plain bearing 33 Slide 34 Rotary drive 35 Spindle 36 Spindle rotation 37 Ball screw nut 38 Sliding bearing 39 Bearing 40 Bearing rods 41 End piece 42 Control

Claims

1. Measuring device (14) for measuring a diameter (9) of spinning cylinders (4) of a top roller (3) of fiber-processing machines, which spinning cylinders are arranged in pairs on an axle pin (5), wherein the measuring device (14) has a laser barrier (25) and a holder (28) for supporting the top rollers (3), characterized in that the measuring device has a distance measuring means (27) and a linear drive (31) for moving (30) the top rollers (3) together with the holder (28) past the laser barrier or for displacing (26) the laser barrier (25) along the holder (28), wherein the holder (28) has a depression (29) for receiving the axle pin (5) of the top roller (3), or a clamping device for fixing the top roller (3) to the holder (28), and in that the measuring device is designed to determine the diameter (9) of the spinning cylinders (4) on the basis of the movement (30) of the holder (28) or the displacement (26) of the laser barrier (25) by the linear drive (31), by means of the laser barrier (25), based on a distance covered by the holder or by the laser barrier, which distance is measured by the distance measuring means.

2. Measuring device (14) according to claim 1, characterized in that the holder (28) is formed having plain bearings (32).

3. Measuring device (14) according to claim 1, characterized in that the holder (28) or the laser barrier (25) is mounted on a sliding carriage (33), wherein the sliding carriage (33) is connected to the linear drive (31).

4. Measuring device (14) according to claim 3, characterized in that the linear drive (31) has a rotary drive (34) and a spindle (35), wherein the sliding carriage (33) is connected to the spindle (35) without play via a ball nut (37) and is held on sliding bearings (38).

5. Measuring device (14) according to claim 4, characterized in that the distance measuring means (27) is integrated into the rotary drive (34).

6. Measuring device (14) according to at least one of the preceding claims, characterized in that a measuring speed and a working speed are provided for the movement (30) of the holder (28) or the displacement (26) of the laser barrier (25), wherein the working speed is a multiple of the measuring speed.

7. Measuring device (14) according to claim 6, characterized in that the measuring speed is 5 mm to 20 mm per second.

8. Measuring device (14) according to at least one of the preceding claims, characterized in that a determination of the diameter (9) of the spinning cylinders (4) with an accuracy of 0.02 mm is provided.

9. Method for measuring a diameter (9) of spinning cylinders (4) of a top roller (3) of fiber-processing machines, which spinning cylinders are arranged in pairs on an axle pin (5), with a measuring device (14) according to at least one of the preceding claims, characterized in that the laser barrier (25) is interrupted by the spinning cylinder (4) during the movement (30) of the top roller (3) or a displacement (26) of the laser barrier (25), and the interruption of the laser barrier (25) triggers an activation and deactivation of the distance measuring means (27).

10. Grinding machine (1) for grinding spinning cylinders (4) of a top roller (3) of fiber-processing machines, which spinning cylinders are arranged in pairs on an axle pin (5), comprising a supply magazine (10) and a discharge magazine (13) and a processing module (12) and comprising a controller (42), characterized in that the processing module (12) has a grinding device (15) having a grinding wheel (16), and a measuring device (14) according to at least one of claims 1 to 8 for determining a diameter (9) of the spinning cylinders (4) prior to a grinding operation.

11. Grinding machine (1) according to claim 10, characterized in that the linear drive (31) and the distance measuring means (27) are evaluated and controlled by the controller (42) of the grinding machine (1).