CN113795617B

CN113795617B - Separation cylinder unit with a device for a pressure cylinder of a separation cylinder pair of a combing machine

Info

Publication number: CN113795617B
Application number: CN202080034183.2A
Authority: CN
Inventors: D·博梅尔
Original assignee: Maschinenfabrik Rieter AG
Current assignee: Maschinenfabrik Rieter AG
Priority date: 2019-05-09
Filing date: 2020-04-30
Publication date: 2023-06-13
Anticipated expiration: 2040-04-30
Also published as: EP3966373A1; WO2020225664A1; CH716167A1; EP3966373B1; CN113795617A

Abstract

The invention relates to a separating drum unit having a device for a pressure drum of a separating drum pair of a combing machine, comprising: a pair of cylinders (20 a, 20 b) consisting of a separating cylinder (22 a) and a pressure cylinder (24 a) rotatable in the combing machine; compression means (26 a, 26 b) for pressing a pressure roller (24 a) and a separation roller (22 a) of a roller pair (20 a) against each other, wherein the pressure roller (24 a) is pressurized via the compression means (26 a) and the compression means (26 a) is connected to a compressed air connection (52). According to the invention, the compressed air connection (52) is connected to a pressure regulator (54) which is designed such that a corresponding pressure for the pressure cylinder (24 a) for pressing against the separating cylinder (22 a) can be set as a function of a predefined rotational speed of the combing machine.

Description

Separation cylinder unit with a device for a pressure cylinder of a separation cylinder pair of a combing machine

Technical Field

The invention relates to a separating drum unit having a device for a pressure drum of a separating drum pair of a combing machine, comprising: a pair of cylinders consisting of a separating cylinder and a pressure cylinder which can be rotated by a reciprocating step motion in a combing machine; at least one pressing device for pressing the pressure roller and the separating roller of the at least one roller pair against each other, wherein the pressure roller is pressurized via the pressing device and the pressing device is connected to a pressure setting device.

Background

In conventional combing machines, as is known from DE 40 39 050 A1, a separating cylinder unit is used, which has a first and a second cylinder pair. These cylinder pairs consist of a separating cylinder and a pressure cylinder, respectively, which can be rotated in a combing machine by means of a reciprocating step motion. The separating drum unit further comprises a pressing device for pressing the pressing drum and the separating drum of each of said drum pairs against each other. In the known separating drum units, the separating drum and the pressure drum of each drum pair are pressed against each other by the pressing device with equal forces, wherein a pressure setting device is provided for this purpose. The known pressure cylinders are configured to set a pressure of approximately 6.5bar in a standardized manner using a pressure setting device.

Against this background, the separating drum is usually grooved and made of steel and the pressure drum is likewise made of metal and provided with a coating made of a rubber-elastic material, resulting in a relatively heavy drum with a large moment of inertia. This results in a high load on the gear mechanism of the combing machine, which causes the separating cylinders of each cylinder pair to have to be rotated back and forth during each combing cycle of the combing machine with a reciprocating step movement during operation. This disadvantageously results in particular at high rotational speeds (greater than 600 KS/min) of the combing machine in non-uniformities in the combed web during the splicing process, which are caused by the different moments of inertia of the pressure cylinder and the separating cylinder.

In particular, the different moments of inertia of each cylinder pair cause slippage between the pressure cylinder and the separating cylinder, which has a significant negative effect on the formation of the web, in particular during the splicing of the combed web. This slippage causes an allowable error between the rotational speed of the pressure cylinder and the rotational speed of the detaching cylinder, which can be in the range of up to 25% for example with a combing cycle number of 650KS/min and a 5bar hold-down pressure applied with the hold-down device. This tolerance in the rotational speed between the pressure cylinder and the separating cylinder is no longer acceptable to the spinning mill owner, since it is directly related to the quality of the carded combed web.

Disclosure of Invention

The object of the present invention is therefore to provide a separating cylinder unit having a device for the pressure cylinders of a separating cylinder pair of a combing machine, which allows a splicing process with a separating cylinder pair of a combing machine to be set in such a way that the quality of the combed web that is carded is acceptable even at higher combing cycles.

This object is achieved by a separating cylinder unit according to the invention with a device for the pressure cylinders of a separating cylinder pair of a combing machine.

A detaching cylinder unit with a device for a pressure cylinder of a detaching cylinder pair of a combing machine is proposed, the detaching cylinder unit having: at least a first cylinder pair consisting of a first separating cylinder and a first pressure cylinder which can be rotated in a combing machine by means of a reciprocating step movement; and a pressing device for pressing the first pressure roller and the first separation roller of the first roller pair against each other, wherein the first pressure roller is pressurized via the pressing device and the pressing device is connected with a pressure interface. According to the invention, the pressure connection is connected to a pressure regulator which is designed such that, depending on the predefined rotational speed of the combing machine, a corresponding pressure for the first pressure cylinder can be set for pressing against the first separating cylinder. The use of a pressure regulator to set the pressure acting on the first pressure cylinder of the first cylinder pair in relation to the first detaching cylinder has the advantageous effect that different moments of inertia between the first pressure cylinder and the first detaching cylinder can be handled in dependence on the rotational speed of the combing machine. The settable pressure thus prevents an excessive deviation between the rotational speed of the first pressure cylinder and the rotational speed of the first separating cylinder, since the pressure is set via the pressure regulator such that the drag applied by the first separating cylinder to the first pressure cylinder does not lead to large rotational speed deviations, so that the splicing process for producing a combed web is greatly improved in comparison with separating cylinder units in which the pressure via the hold-down device remains constantly at the same pressure level irrespective of the set rotational speed of the combing machine. In this connection, it is generally known to carry out the splicing process in a combing machine in such a way that: the separating cylinders perform a reciprocating movement via the drive of the combing machine, wherein the individual fibre groups carded via the circular comb are stacked on top of one another in roof tile-like fashion and spliced during the splicing process via a cylinder pair consisting of a pressure cylinder and a separating cylinder.

Preferably the pressure regulator comprises at least one electrically controllable pressure valve. The electrically controllable pressure valve is designed to throttle the system pressure of the pressure line and thus to transmit the reduced pressure to the pressure device. The pressure regulator has the task of controlling the pressure valve in this case, so that a stepless pressure setting for the first pressure cylinder of the first cylinder pair is possible.

It should be mentioned at this point that the pressure regulator according to the invention can of course also be adjusted manually in order to set the desired pressure acting on the pressure cylinder, wherein such manual use is particularly inaccurate and entails the risk of mechanical overload of the components.

Furthermore, the pressure regulator preferably sets a corresponding pressure of between about 210N and about 642N as a function of the rotational speed of the combing machine. This preferred pressure for the pressure cylinder allows an actually usable adaptation of the pressure ratio of the cylinder pair to the rotational speed of the combing machine by means of a pressure regulator.

In particular, the predefined rotational speed of the combing machine is at least approximately linearly dependent on the settable pressure for the first pressure cylinder. The linear dependence of the set rotational speed of the combing machine on the pressure required for the first pressure cylinder has the advantageous effect that the pressure regulator can set the pressure particularly simply and reproducibly in relation to the actual rotational speed of the combing machine. In this way, it is achieved that the rotational speed deviations of the pressure cylinder and the separating cylinder, which are caused by the different moments of inertia, are kept as small as possible.

Furthermore, the rotational speed of the combing machine is preferably between 400KS/min and 700 KS/min. It has proven to be particularly advantageous for the pressure regulator to set a pressure of between about 210N and about 214N, particularly preferably about 212N, at a combing machine speed of 400KS/min, a pressure of between about 420N and about 428N, particularly preferably about 424N, at a combing machine speed of 550KS/min, and a pressure of between about 630N and about 640N, particularly preferably about 636N, at a combing machine speed of 700 KS/min.

Furthermore, it is preferred that a slip between the first pressure cylinder and the first detaching cylinder with a maximum tolerance of 3.0% is set as a function of the predefined rotational speed of the combing machine in combination with the corresponding pressure energy. The slip in this context means the rotational speed difference between the first separating cylinder and the first pressure cylinder of the first cylinder pair, which is caused by the different moments of inertia of the two components of the first cylinder pair in combination with the rotational speed of the combing machine. Thus, a slip as referred to herein is a mechanical interaction of two rotating members, wherein the slip becomes greater once the frictional or interaction force between the two members becomes too small. In a physical explanation, with reference to a constant 3bar hold-down force of a pressure cylinder with a conventional piston diameter of 26mm, the hold-down force exerted by the pressure cylinder on the detaching cylinder is so small at a higher number of combing cycles, such as 600KS/min, that the detaching cylinder rotates significantly faster than the pressure cylinder, whereby a considerable speed difference between the two components occurs, which speed difference causes slippage. Experiments have shown that the tolerance between cylinder pairs is about 55% at a pressure of 3bar and a combing cycle number of 600 KS/min. Thus, the higher the pressure onto the pressure roller, the smaller the tolerance for slippage of the roller pair.

In particular, the control unit is preferably connected to the pressure regulator and has a data memory in which a data record is stored for a 3.0% tolerance for slippage between a predefined rotational speed of the combing machine and the corresponding pressure, so that the control unit sets the correct pressure for the first pressure cylinder via the pressure regulator as a function of the set rotational speed of the combing machine. It has proven advantageous if the slip between the pressure cylinder and the separating cylinder is in the tolerance range between 0.1% and maximally 3.0%, since the quality in forming the web is still acceptable in this tolerance range. The tolerance increases approximately exponentially as a function of the rotational speed with a constantly set pressure, so that the approximately exponentially tolerance can be balanced with the negative effects of slippage merely by a variable adaptation of the pressure regulator according to the invention.

Furthermore, a rotation angle sensor is preferably provided, which monitors the rotational speed of the combing machine and transmits it to the control unit for setting the correct pressure for the first pressure cylinder via the pressure regulator as a function of the predefined rotational speed of the combing machine. The electrical connection of the angle sensor, the pressure regulator and the control unit enables an optimal regulation of the pressure cylinder as a function of the rotational speed of the combing machine.

In particular, the pressing device preferably has a first piston for the first pressure cylinder, which piston can be acted upon by a pressure medium, preferably air, wherein the first piston is connected to the compressed air connection via a pressure regulator. The shape of the pressure regulator has the advantageous effect that the control of the pressure can be defined via the cross section of the piston, wherein the control unit controls via the pressure regulator an electrically controllable pressure valve for the pressure medium for loading the piston. The pressure medium is preferably compressed air, which is supplied by a compressed air line and is controllably transferred to the piston via an electrically controllable pressure valve for generating the desired pressure.

Furthermore, it is preferred that the first piston has a diameter which is configured such that a pressure between about 210N and about 640N for the first pressure cylinder can be set via the pressure regulator. This has the advantageous effect that the pressure cylinder has an optimum pressing force for achieving a good splice connection of the carded fibre groups as a function of the rotational speed of the combing machine. With reference to the claimed values for minimum pressure and maximum pressure according to the rotational speed of the combing machine, a pressure value deviation of +/-1.0% is considered to be in the claimed value range.

Preferably the first piston has a diameter of about 30mm to about 38mm, preferably about 32 mm. In this way, the desired pressure acting on the first pressure cylinder is advantageously set, without even approaching a system pressure range of approximately 6.9 bar. In this way, the use of only a small fraction of the system pressure for the desired pressure is achieved without problems with the embodiment of the claimed piston. Furthermore, this differs from conventional pistons in which the piston diameter is in the range of 26mm and therefore the first pressure cylinder already requires a system pressure of approximately 7bar for a desired pressure of approximately 500N with an average combing working cycle of 550 KS/min. In this connection, it is to be mentioned that manual adjustment of the pressure cylinder with the piston geometry claimed above carries the risk that a mechanical overload of the piston will occur particularly quickly, since the user is accustomed to setting to 6.5bar in a conventional procedure, which results in a comparatively high pressure on the piston. The use of the piston geometry claimed above for the pressure cylinder is thus achieved in a reliable manner, in particular with the pressure regulator according to the invention, since a particularly accurate setting of the pressure regulator is achieved in a preferred manner in conjunction with the pressure valve via the control unit.

A second cylinder pair consisting of a second separating cylinder and a second pressure cylinder which can be rotated in a reciprocating step motion in the combing machine is preferably provided, wherein the second cylinder pair is connected downstream of the first cylinder pair in the transport direction of the web. The second cylinder pair is connected downstream of the first cylinder pair seen in the transport direction of the web and accordingly guides the fibre groups which have been carded out and spliced together again to the transport rollers connected downstream in a known manner.

In particular, the respective hold-down device is configured to apply a first pressure to a first pressure cylinder of the first cylinder pair and a second pressure to a second pressure cylinder of the second cylinder pair via the pressure regulator, wherein the second pressure is greater than the first pressure as a function of the rotational speed of the combing machine. The control unit enables the setting of the pressure regulator for a second, greater pressure relative to the first, smaller pressure to obtain a regular combed web with smooth edges in an advantageous manner. Since the respective pressure is set as a function of the rotational speed of the combing machine, a correspondingly high-quality combed web can be set without problems for the number of combing cycles of the combing machine from 400KS/min to 700 KS/min.

Preferably the second pressure is at least 10% greater than the first pressure. In this way, the acceleration difference between two adjacent pairs of cylinders due to the different torque between the respective pressure cylinder and the respective separation cylinder of each respective pair of cylinders can be optimally balanced to maintain the quality of the combed web. In this connection, it is to be mentioned that, in particular, a possible cause for a different acceleration between two adjacent roller pairs arises as a result of the reciprocating step movement of the first roller pair facing the pliers having a further or altered acceleration in the interaction with the pressure roller compared to the second roller pair connected downstream.

Alternatively, the different pressures for the first pressure cylinder and the second pressure cylinder are also set by the dimensioning of the first piston relative to the second piston or rather the diameter being changed, wherein in this embodiment only one pressure regulator is sufficient which transmits the same system pressure in the form of air to the respective differently dimensioned pistons and thus generates different first pressures relative to the larger second pressure, which pressures act on the respective pressure cylinders.

The invention further relates to a combing machine having a separating cylinder unit according to the invention.

Drawings

Wherein:

fig. 1 shows a side view of parts of a comber head with a separating drum unit comprising two drum pairs;

FIG. 2 illustrates a conventional adjustment of a circular comb and separation cylinder unit;

FIG. 3 shows a schematic view of the cylinder pair according to FIG. 1 with a separating cylinder movement and a pressure cylinder movement at constant hold-down force and different combing working cycles;

FIG. 4 shows a schematic diagram of the tolerance of the cylinder pair according to FIG. 3 depending on the number of different combing cycles;

fig. 5 shows a control unit for monitoring the rotational speed of a circular comb and the adjustment of the pressing force of the pressure cylinder according to fig. 1 via a pressure regulator according to the invention;

FIG. 6 shows a graph of the tolerance of the cylinder pair according to FIG. 1 at different hold-down forces and different combing cycles;

FIG. 7 shows a schematic of the tolerance of the cylinder pair with respect to the pressure cylinder as a function of the number of combing operating cycles;

FIG. 8 shows a schematic representation of the pressure onto the pressure cylinder according to the number of combing working cycles for a tolerance of 3% for the cylinder pair according to FIG. 7; and

fig. 9 shows a side view of parts of a combing head with another detaching cylinder unit.

Detailed Description

Fig. 1 shows a purely schematic representation of an enlarged section of parts of a combing head 10 of a combing machine, with an oscillating nipper 12 comprising an upper nipper 14 and a lower nipper 16. The pliers 12 are shown in the forward position with the roller unit 18 separated. The separating drum unit 18 comprises in this example two

drum pairs

20a, 20b arranged parallel to each other. The first cylinder pair 20a adjacent to the nipper 12 consists of a first separating cylinder 22a and a first pressure cylinder 24a, and the second cylinder pair 20b further away from the nipper 12 in the transport direction of the combed web consists of a second separating cylinder 22b and a second pressure cylinder 24 b.

In operation, the pliers 12 are in the rear position in a known manner, in which the fiber bundle is clamped firmly at the clamping point between the lower and

upper pliers plates

16, 14 and is carded out by a rotating circular comb (not shown).

The nipper 12 is then moved into the forward position as shown in fig. 1 and opened, wherein the separating

cylinders

22a, 22b are rotated by a drive (not shown) included in the combing machine by a predetermined angle in the clockwise direction, so that the rear end of the previously formed combed web comes out of the clamped position of the first cylinder pair 20a and the front end of the fiber bundle lying on the lower nipper 16 and combed with a circular comb engages in roof-tile or scale-like fashion on said rear end. The separating

drums

22a, 22b are then rotated in a counter-clockwise direction through a predetermined second, larger angle for grasping, splicing and separating the fiber bundles via the drum pairs 20a, 20b.

The separating drum unit 18 comprises in this example for each

drum pair

20a, 20b a separate pressing device, namely a first pressing device 26a or a second pressing device 26b, for pressing the separating

drum

22a or 22b and the

pressure drum

24a or 24b against each other. Each

pressing device

26a or 26b comprises a

bearing support

28a or 28b for a

respective bearing

30a or 30b of the two

pressure cylinders

24a or 24 b. The block 32 comprises, for each of the bearing supports 28a or 28b, a

separate piston

34a or 34b, the associated

bearing support

28a or 28b being fastened to the

piston rod

36a or 36b of the piston, wherein the

respective piston

34a or 34b is guided displaceably in the block 32, which is fixed in operation relative to the machine frame. The block 32 comprises, above the upper end of the

respective piston

34a or 34b, a

respective chamber

38a or 38b which, in operation, is supplied with compressed air via a duct, not shown, in order to push the

respective piston

34a or 34b and thus the

respective bearing bracket

28a or 28b downwards and thus press the

respective pressure cylinder

24a or 24b towards the

respective separation cylinder

22a or 22b with a pressure defined via the diameter 40 of the piston 34. In this embodiment the first piston 34a and the second piston 34b have the same diameter of about 32 mm.

Fig. 2 shows a conventional control device 42 purely schematically, which is used for a known reciprocating step movement of the separating drum unit 18 according to fig. 1 for producing the separating drum via the first drive motor 44 and for the circular comb 46 for producing the rotary movement via the second drive motor 48, wherein the two

drive motors

44, 48 are coordinated with one another via the control unit 50.

As can also be seen from fig. 2, the compressed air connection 52 of the pressure cylinder for the separating cylinder unit 18 as described in fig. 1 is directly connected to the respective piston (indicated by two arrows), so that a system pressure of approximately 7bar acts unfiltered in the form of compressed air on the piston of the pressure cylinder via the compressed air connection. In the case of the known pressure cylinder, the diameter of the piston in the known separating cylinder unit 18 is approximately 26mm in size, so that a constant pressing force in the sense of a pressure of approximately 495N presses the pressure cylinder against the separating cylinder in the case of a system pressure of approximately 7 bar.

Simultaneously with the constant pressing force of 495N on the separating drum by the pressure drum, a reciprocating step motion is performed for the separating drum via the first drive motor 44, so that a roof tile-like splicing of the fibre groups carded out by the circular comb 46 with the drum pairs can be achieved. In this case, a so-called dragging of the pressure cylinder takes place, which is caused by the rotational movement of the separating cylinder, wherein the separating cylinder rotates actively via the drive motor 44 and the pressure cylinder rotates passively together. Furthermore, the carded fibre group is clamped in a roof-tile manner between the cylinder pairs and the two cylinders are pressed against one another via a constant pressing force of 495N, wherein in this way the quality of the spliced fibre web is defined in the case of conventional combing machines.

In this connection, it is to be defined that the drag exerted by the separating drum on the pressure drum is generated in that the rotational movement of the separating drum generates a counter force which acts against the constant pressing force of the pressure drum.

Fig. 3 shows the cylinder strokes of the separating cylinder ARZ (bold solid black) and the pressure cylinder DRZ (solid black) respectively associated with the machine index of each combing working cycle. Fig. 3 also shows the cylinder travel of the pressure cylinder DRZ depending on the number of combing working cycles set differently between 350KS/min and 700 KS/min.

Looking carefully at fig. 3, the first part of the cylinder travel of the separating cylinder ARZ is a predetermined angle in the clockwise direction (see Y-axis from 0mm to-57 mm), then a reversal of the cylinder travel of the separating cylinder ARZ in the counterclockwise direction at a larger predetermined second angle occurs at-57 mm, a linear rise to 10mm, and then a plateau occurs at 26 mm. The cylinder travel curve is typically implemented in a so-called reciprocating step motion for the separating cylinders on a combing machine, so that the individual fibre groups combed with the circular and top combs are roof-tile-like on top of one another and can be spliced to one another with sufficient pressing force (f=495N) with at least the first cylinder pair according to fig. 1. Corresponding to the cylinder travel curve of the detaching cylinder ARZ, the cylinder travel of the pressure cylinder DRZ runs in the exactly reversed circumferential travel direction per combing working cycle simultaneously with the cylinder travel of the detaching cylinder ARZ.

The splicing process with the roller pairs, as shown in fig. 3, takes place in the range of 10mm to 26mm and in the machine index of 24 to 40, that is to say in the range in which the separating rollers are driven in the counterclockwise direction and the pressing force for the stability of the spliced web is obtained via the pressure rollers.

According to the bold solid black line with the mark ARZ, the cylinder stroke of the detaching cylinder ARZ at a combing working cycle number of about 320KS/min and a constant hold-down force of 495N is just the reversed cylinder stroke of the pressure cylinder DRZ shown as a solid black line. Accordingly, the drum strokes of the separation drum and the pressure drum are equal in value at about 320KS/min and 495N.

As is evident from fig. 3 at a constant hold-down force of 495N, the cylinder travel traversed by the pressure cylinder decreases discernably with increasing combing operating cycles. This causes an undesired mechanical slip between the pressure cylinder and the detaching cylinder, since the cylinder travel of the detaching cylinder ARZ does not change at higher combing cycles, but the cylinder travel of the pressure cylinder DRZ is reduced due to the faster feed of the carded fibre group (see different dashed lines and arrow directions in fig. 3). In other words, the cylinder travel of the pressure cylinder is shortened at the increased number of combing cycles and at the constant cylinder travel of the separating cylinder, whereby the different cylinder travel depending on the number of combing cycles greatly influences the splicing process, since the constant contact force exerted by the pressure cylinder on the separating cylinder is no longer sufficient to rotate at the same or at least approximately the same rotational speed as the separating cylinder. The reason for the reduced rotational speed of the pressure cylinder, which is dependent on the higher number of combing cycles or the higher circular combing speed, can be explained by the fact that the faster supply of the carded fibre mass together with the rotational movement of the separating cylinder no longer applies a sufficient counter force in the form of a drag to the pressure cylinder, so that at a constant hold-down force of 495N the rotational speed of the pressure cylinder can no longer be adapted to the rotational speed of the separating cylinder, whereby a different cylinder stroke is caused for the pressure cylinder according to fig. 3.

Fig. 4 shows the percentage tolerance of the cylinder pair as a function of the number of combing working cycles according to the cylinder stroke shown in fig. 3 at a constant hold-down force F with a machine index of 40 and 495N. The effect of the number of combing cycles on the tolerance error between the two cylinders of the cylinder pair (ARZ vs DRZ) is particularly clearly shown in this figure. From combing duty cycles greater than 580KS/min, the tolerance increases approximately exponentially, which results in a significant quality loss during the splicing process by the cylinder pair. In principle, a maximum tolerance of 3% for a roller pair for a qualitative splicing process is also acceptable, but this is no longer given at a constant hold-down force of 495N and a combing cycle number of greater than 580KS/min (as is shown by the dashed boundary line in fig. 4).

Fig. 5 shows schematically how the control unit 50 is in connection with the pressure regulator 54 according to the invention in connection with the separation cylinder unit 18 according to fig. 1 and the circular comb 46 of the combing machine.

The compressed air connections 52 are each connected via an electrically controllable pressure valve 56 to a piston of the separating drum unit 18 described in fig. 1, and the pressure regulator 54 controls the electrically controllable pressure valve 56 via the control unit 50. A system pressure of approximately 6.9bar is applied to the compressed air connection 52 and a pressure of between 0.1bar and 6.9bar can be set steplessly via an electrically controllable pressure valve 56 in combination with a pressure regulator 54.

In addition to the pressure regulator 54, a rotation angle sensor 58 is connected to the control unit 50, wherein the rotation angle sensor 58 detects the rotational speed of the circular comb 46. The control unit 50 is configured to monitor the rotational speed of the circular comb 46 via a rotational angle sensor 58 and to set a desired pressure acting on the pressure cylinder of the separation cylinder unit 18 via a pressure regulator 54. The control unit 50 also comprises a data memory 60 with data concerning the combing machine speed in combination with the pressure of the pressure cylinder for the detaching cylinder unit 18 to ensure, via the pressure regulator 54, that a maximum tolerance of not more than 3% is provided between the speed of the pressure cylinder and the speed of the detaching cylinder.

As mentioned above, the electrically controllable pressure valve 56 can be controlled via the pressure regulator 54 according to the invention in combination with the control unit 50 in such a way that the system pressure applied at the compressed air connection 52 can be steplessly set from 0.1bar to a maximum of 6.9bar, wherein the piston of the pressure cylinder according to fig. 1 is dimensioned in such a way that the pressure between 210N and 610N is already sufficient for achieving a maximum tolerance of 3% depending on the rotational speed of the combing machine.

According to the invention, it is thus possible to set a pressure according to the number of combing working cycles using a pressure regulator, which pressure allows the rotational speed of the pressure cylinder to be unchanged excessively relative to the rotational speed of the detaching cylinder, thereby significantly preventing the mechanical slippage set forth in fig. 2. In an active manner, a high quality of the splicing process with roller pairs can thus be maintained as a function of the number of combing cycles.

Fig. 6 shows the tolerance of the cylinder pair according to fig. 1 as a function of the rotational speed of the combing machine and with different pressing forces applied with the pressure regulator according to the invention as described in connection with fig. 5. The tolerance of the roller pair shown illustrates particularly well the dependence on the number of combing cycles and on the pressure. The smaller the pressure, the higher the tolerance at the elevated combing duty cycle and vice versa.

To illustrate the dependence of the tolerance of the cylinder pair with respect to the applied pressure of the pressure cylinder and with respect to the number of combing cycles, see figure 7. The Y-axis is expressed logarithmically here, thereby clearly showing that the tolerance of the roller pair drops at least approximately linearly with respect to the pressure rise. As can be seen from fig. 7, the tolerance of the cylinder pair is many times higher at elevated pressures and high combing cycles in the range of 600KS/min to 700KS/min than at low combing cycles between 400KS/min and 550 KS/min. Also shown in fig. 7 by the horizontal dashed line, at which pressure the tolerance of the cylinder pair has a maximum tolerance of 3% for different combing cycles. This is correspondingly shown in fig. 8, in which the X-axis defines the number of combing cycles of 400KS/min to 650KS/min and the Y-axis has the pressure of the pressure cylinder with a maximum tolerance of 3% as can be seen in fig. 7. Clearly and clearly shownThe result is an at least approximately linear relationship between the increase in the number of combing cycles and the increase in the pressure of the pressure cylinder (deviation R ² =0.9999) to obtain a maximum allowable error of 3%.

Fig. 9 shows a further alternative embodiment of a separating drum unit 18B, wherein the two pistons 34a 'and 34B' each have a different first smaller diameter 40a and a different second larger diameter 40B, respectively, in a unique manner from the embodiment according to fig. 1. Due to the different diameters 40a or 40b of the first piston 34a 'and the second piston 34b', different pressures can be transmitted to the first pressure cylinder 24a via the first piston 34a 'and to the second pressure cylinder 24b via the second piston 34b' with the same compressed air. The pressure via the second piston 34b 'is here greater than the further pressure via the first piston 34 a'. The pressure regulator according to fig. 5 can also be used in this embodiment of the detaching cylinder unit 18B to set the respective pressure according to the number of combing cycles such that the mechanical slip between the respective pressure cylinder 24a, 24B and the respective detaching cylinder 22a, 22B has a maximum tolerance of 3%.

In this connection, it is to be mentioned that the pressure regulator for setting the pressing force of the pressure cylinder can also be used when the quality of the carded web after the splicing process with the separating cylinder unit is not in the predefined quality range. The quality of the carded web is defined on the basis of the belt uniformity by the so-called CV value, wherein the accuracy of the output belt is continuously monitored by means of a movable calendar disk in combination with a contactless induction/vortex sensor. Such quality monitoring systems are known, for example, under the name RQM. Readiness monitoring (RQM) in-line monitoring, in particular, of the coarse points of the web, wherein the coarse points are an indicator of whether the settings for the pairs of separating cylinders used in the splicing process are satisfactory. Accordingly, the sensor for monitoring the coarse spots in the case of insufficient web quality can transmit a data signal via the signal line to the control unit, wherein the control unit correspondingly controls the pressure regulator in such a way that the pressure roller of the roller pair attains a sufficient pressing force for again achieving the optimum web quality. Accordingly, RQM in combination with pressure regulators is a particularly good quality monitoring system for carded webs.

In this connection, it is to be mentioned that the pressure regulator can be set as a function of the number of combing cycles and/or as a function of the quality of the carded web, wherein the importance is given to the quality of the carded web in terms of strength through the splicing process and to the minimization of the coarse spots in order to ensure an optimal quality of the yarn in the final spinning process.

List of reference numerals

10	Combing head
		12	Pliers with pliers body
14	Upper nipper
		16	Lower nipper
18、18B	Separating roller unit
		20a、20b	Roller pair
22a、22b	Separating drum
		24a、24b	Pressure roller
26a、26b	Compacting device
		28a、28b	Bearing support
30a、30b	Bearing
		32	Block and method for manufacturing the same
34a、34b	Piston
		36a、36b	Piston rod
38a、38b	Cavity(s)
		40a、40a‘、40b‘	Diameter of
42	Control device
		44	First driving motor
46	Round comb
		48	Second driving motor
50	Control unit
		52	Compressed air interface
54	Pressure regulator
		56	Pressure valve
58	Rotation angle sensor
		60	Data storage

Claims

1. A detaching cylinder unit having means for a pressure cylinder of a detaching cylinder pair of a combing machine, the detaching cylinder unit having: at least one first cylinder pair (20 a) consisting of a first separating cylinder (22 a) and a first pressure cylinder (24 a) rotatable in the combing machine with reciprocating step motion; at least one first pressing device (26 a) for pressing the first pressure cylinder (24 a) and the first separating cylinder (22 a) of the first cylinder pair (20 a) against each other, wherein the first pressure cylinder (24 a) is pressurized via the first pressing device (26 a) and the first pressing device (26 a) is connected to a compressed air connection (52), characterized in that the compressed air connection (52) is connected to a pressure regulator (54), which is configured such that a corresponding pressure for the first pressure cylinder (24 a) for pressing against the first separating cylinder (22 a) can be set as a function of a predefined rotational speed of the combing machine.

2. A separation drum unit according to claim 1, characterized in that the pressure regulator (54) comprises at least one electrically controllable pressure valve (56).

3. A detaching cylinder unit according to claim 1 or 2, characterized in that the pressure regulator (54) sets the respective pressure between 210N and 640N in accordance with the rotational speed of the combing machine.

4. A detaching cylinder unit according to claim 1 or 2, characterized in that the predefined rotational speed of the combing machine is at least approximately linearly dependent on the settable pressure for the first pressure cylinder (24 a).

5. A detaching cylinder unit according to claim 1 or 2, characterized in that the predefined rotational speed of the combing machine is between 400KS/min and 700 KS/min.

6. The separating cylinder unit according to claim 1 or 2, characterized in that a slip between the first pressure cylinder (24 a) and the first separating cylinder (22 a) with a maximum tolerance of 3.0% is set in accordance with the predefined rotational speed of the combing machine in combination with the corresponding pressure energy.

7. The detaching cylinder unit as claimed in claim 6, characterized in that a control unit (50) is connected to the pressure regulator (54) and has a data memory (60) in which a data set of 3% tolerance to the slip between a predefined rotational speed of the combing machine and the respective pressure is stored, so that the control unit (50) sets the correct pressure for the first pressure cylinder (24 a) via the pressure regulator (54) in accordance with the set rotational speed of the combing machine.

8. A detaching cylinder unit according to claim 7, characterized in that a rotation angle sensor (58) is provided, which monitors the rotational speed of the combing machine and transmits it to the control unit (50) for setting the correct pressure for the first pressure cylinder (24 a) via the pressure regulator (54) in accordance with a predefined rotational speed of the combing machine.

9. The separation drum unit according to claim 1 or 2, characterized in that the first pressing device (26 a) has a first piston (34 a) which can be acted upon by a pressure medium for the first pressure drum (24 a), wherein the first piston (34 a) is connected to the compressed air connection (52) via the pressure regulator (54).

10. The separation drum unit according to claim 9, wherein the pressure medium is air.

11. The separation drum unit according to claim 9, characterized in that the first piston (34 a) has a diameter (40) configured such that a pressure between 210N and 640N can be set for the first pressure drum (24 a) via the pressure regulator (54).

12. The separation drum unit according to claim 11, characterized in that the first piston (34 a) has a diameter (40) between 30mm and 38 mm.

13. The separation drum unit according to claim 12, characterized in that the first piston (34 a) has a diameter (40) of 32 mm.

14. A separating cylinder unit according to claim 1 or 2, characterized in that a second cylinder pair (20 b) is provided, which consists of a second separating cylinder (22 b) and a second pressure cylinder (24 b) which can be rotated in a reciprocating step movement in the combing machine, wherein the second cylinder pair (20 b) is connected downstream of the first cylinder pair (20 a) in the transport direction of the web.

15. The detaching cylinder unit according to claim 14, characterized in that the respective pressing device is configured to apply a first pressure to a first pressure cylinder (24 a) of the first cylinder pair (20 a) and a second pressure to a second pressure cylinder (24 b) of the second cylinder pair (20 b) via the pressure regulator (54), wherein the second pressure is greater than the first pressure as a function of the rotational speed of the combing machine.

16. Combing machine having a separating cylinder unit (18) according to any one of claims 1 to 15.