CN1690267B - Fiver rod separating method and yarn preparing machine - Google Patents

Abstract

The invention provides a method for guiding a fiber sliver (FB') to start the separation process at the output of a spinning preparation machine, in particular at the output of a draw frame or carding machine, wherein the draw frame or The card is equipped with a drafting device (4) with a number of roller pairs (5a, 5b, 6a, 6b, 7a, 7b, 9), in which the fiber sliver (FB') is drawn and then The pair of press rollers (13, 14) is fed to a coiler device with a fiber sliver track (16) and a turntable (17), and is deposited with the coiler device in a drum (18) for storage. The inventive method is characterized in that the fiber sliver (FB') is clamped and conveyed by a pair of downstream roller pairs (7a, 7b; 7a, 9; 13, 14), and is clamped and conveyed by at least one pair of upstream roller pairs (6a, 6b; 7a , 7b; 7a, 9) stop the clamping state of the fiber sliver (FB'), in the fiber sliver (FB'), in the above-mentioned downstream roller pair (7a, 7b; 7a, 9; 13, 14) and the A sliver detail (DS1; DS2) or a end break (BB) occurs between at least one upstream roller pair (6a, 6b; 7a, 7b; 7a, 9). The present invention proposes corresponding spinning preparation machine simultaneously.

Description

Fiber sliver separation method and spinning preparation machine

technical field

The invention relates to a method for guiding a fiber sliver to start the separation process at the output of a spinning preparation machine, in particular at the output of a draw frame or card, wherein the draw frame or card Equipped with a drafting device with a number of roller pairs, the fiber sliver is drawn in the drafting device, and then transported to the coiler device by the pressure roller pair, and is deposited in a drum by this device. the

In addition, the invention also relates to a spinning preparation machine, in particular a drawing frame or carding machine, wherein the drawing frame or carding machine is equipped with a drafting device with a plurality of roller pairs, on which the fiber sliver can be drawn. The stretched fiber sliver is stretched in the drafting device, and then compressed and transported in the rolling direction by the pressure roller pair, and input and thrown into a cylinder by the sliver device. the

Background technique

Various methods are known to guide the separation of the fiber sliver at the output of a spinning preparation machine, in particular at the output of a drawing frame or carding machine, for can changing. Filling with fiber sliver, especially the can filled with fiber sliver, must leave the coiler device and be fed into an empty can subsequently. In this process, the fiber sliver output from the spinning preparation machine must be separated from the spinning preparation machine, so that the end of the fiber sliver away from the machine is thrown away in the filled can or on the can, and the fiber sliver close to the machine is thrown away. One end is fed into an empty can. the

For example, according to a known method of the German patent EP 681 983 B1, there is a clamping device at the output of the draw frame to catch the fiber sliver, wherein, when the filled can is removed, the fiber is placed on the clamping device. The strip broke. Then, the end of the fiber sliver close to the machine is introduced into the empty can. The disadvantage of this device is that the moving parts used on the fiber sliver separator are relatively susceptible to interference and wear, and when the material is changed, the fiber sliver separator needs to be readjusted, which is time-consuming and labor-intensive. the

According to German patent DE 195 48 232 A1 known a kind of equipment, this equipment produces a sliver detail on drafting device by improving the degree of drafting of main drafting zone. The fiber sliver with the sliver details is then transported through the coiler unit with calender rolls until the sliver details reach the coiler unit opening. At this moment, the machine is stopped or the conveying speed is drastically reduced in order to discharge the filled can so that the yarn detail is broken at the edge of the fiber sliver exit. A disadvantage of this arrangement is that, for example, on a non-speed-regulated draw frame, this function can only be reliably implemented if the machine is equipped with a single drive for the center roller pair and the output roller pair respectively. In addition, the resulting sliver details are very long, which is not conducive to further processing. the

Another method according to European patent EP 593 587 B1 is to utilize the difference in delivery speed between the output roller pair and the calender roller pair to carry out the separation of the fiber sliver. This design requires an additional electric motor as the calender drive, which of course requires additional costs. the

Contents of the invention

The object of the present invention is to provide a simple method for guiding the separation process of the fiber sliver and to provide a corresponding spinning preparation machine. the

The above-mentioned task of guiding the separation process of the fiber sliver in a simple way is solved in that the fiber sliver is gripped and conveyed by a pair of downstream roller pairs, and at the same time, at least one pair of upstream roller pairs stops gripping the fiber sliver, resulting in The fiber sliver between said downstream roller pair and said at least one upstream roller pair produces sliver details or end breaks. Namely: A method of guiding a fiber sliver to start the separation process at the output of a spinning preparation machine, in particular at the output of a draw frame or card, wherein the draw frame or card is equipped with A drafting device with several roller pairs is provided, in which the fiber sliver is stretched, then conveyed by means of pressure roller pairs to a coiler device with a fiber sliver path and a turntable, and is thrown away by means of the coiler device Stored in a cylinder, it is characterized in that the fiber sliver is clamped and conveyed by a pair of downstream rollers, and the clamping state of the fiber sliver is stopped by at least one pair of upstream rollers, at this time, the fiber sliver is on the above-mentioned downstream roller pair and A sliver detail or a broken end occurs between the at least one upstream roller pair. the

In addition, the above-mentioned task with respect to a corresponding spinning preparation machine is solved by corresponding spinning preparation machine, the clamping state of fiber sliver on at least one pair of upstream roller pairs can be shortened by the reduction of the pressure of this roller pair. Time is suspended, and the fiber sliver under the clamping of the downstream roller pair is then continued to be conveyed, thus the fiber sliver between the said at least one upstream roller pair and the said downstream roller pair just produces sliver details or broken ends. Namely: spinning preparation machines, in particular drawframes or carding machines, equipped with a drafting unit with a number of roller pairs in which the fiber sliver is Connected pair of press rollers to compress and transport the stretched fiber sliver, and equipped with a fiber sliver channel to transport and deliver the fiber sliver to the can for storage, characterized in that the fiber sliver is clamped on at least one pair of upstream roller pairs On the other hand, by reducing the pressure on the pair of rollers, the above-mentioned clamping state can be suspended for a short time, but the fiber slivers can be clamped by a pair of downstream rollers and continue to be transported, and between the above-mentioned at least one pair of upstream rollers and the downstream Sliver details or end breaks are produced in the fiber sliver between the roller pairs. the

It can be seen that the advantages of the invention are especially that, while a sliver detail or end break occurs, at least one of the two pairs of rollers is decompressing, so that the clamping of the fiber sliver is discontinued on this roller pair. During the decompression time, the fiber sliver is conveyed further for a short time (sometimes after an earlier stop) by means of the downstream roller pair. Based on the inertia of the fiber sliver, the sliver details are generated under impact, or alternatively the desired end breaks are generated. When the fiber sliver has relatively long fibers, it is advantageous that several consecutive impacts take place. As an alternative or in addition, the friction of the fiber sliver at a certain point of the drafting device can also be used to achieve sliver detailing or end breaks or to support the process. According to the design of the invention, it is also possible to make full use of different speed ratios between the different pairs of rollers involved in the operation. Another advantage of the invention is that it is not necessary to change the drafting state in the drafting device relative to the normal operating state of the machine; rather, the drafting state can be kept constant. the

According to a preferred embodiment of the present invention, sliver detail or broken end is produced like this, promptly: press roller pair conveys fiber sliver for a short time, at the same time, the pressure of front delivery roller pair reduces or stops completely, causes The clamping state of the fiber sliver on the output roller pair is also completely suspended. Thus, sliver details or end breaks occur between the delivery roller pair working as an upstream roller pair and the press roller pair working as a downstream roller pair. According to this embodiment, the fiber sliver is elongated after the drafting device. the

If a reversing upper roller is placed behind the upper output roller, then the roller pair formed by such a reversing upper roller and the lower roller can also serve as an upstream roller pair that meets the needs of the present invention. The advantage is that the top delivery rollers can be decompressed together with the reversing top rollers, since both have the same peripheral speed. the

As a kind of optional alternative, the pair of rollers formed by changing the upper roller and the lower output roller can also serve as the pair of downstream rollers meeting the needs of the present invention, while the pair of upstream rollers meeting the needs of the present invention is the pair of output rollers, On this pair of rollers, the clamping state is briefly suspended, or more precisely, the clamping state can be temporarily suspended. Sliver details or end breaks (as in the first test results) occurred within the range of the previous clamping position on the output roller pair. the

Depending on the design of the drafting unit, it may be best practice that not only the last roller pair placed before the press roller pair must be decompressed in order to produce sliver details or end breaks, but also the remaining roller pairs of the drafting unit. Must decompress. It should be noted that the upper drafting device roller pairs neither use spring force nor pneumatic systems to pressurize the fixedly positioned lower rollers, thereby causing a clamping action on the fiber sliver on each roller pair. The top roller, together with its various pressurizing devices, can be supported on a swingable load arm, usually pressurized with pneumatic tie iron. All top rollers of the drafting unit can be raised by centralized pressurization of the load arm by means of a pneumatic system. the

For the above-described embodiment in which a sliver detail or a broken end occurs between a pair of delivery rollers (or more precisely, reversing upper and lower delivery rollers) and a pair of press rollers, preferably according to a certain embodiment, At least the pressure roller pair (preferably from a standstill) is accelerated with a short trigger pulse, while the clamping state is terminated at the preceding roller pair. According to a preferred variant of the invention, the pulse width of the trigger pulse is selected according to the sample length of the fiber material to be processed. For example, the so-called hand-pulled length or cut length (for synthetic fibers), or the average fiber length or other fiber length properties, can be chosen as a standard value for the pulse width. The advantage of this is that the pulse duration is calculated internally by the machine's calculation component after the operator enters the corresponding value, eg for a polyester fiber (PES) length of 38 mm. the

As an alternative, the trigger pulse may be selected on a purely time-based basis, for example with a duration of about 1 to 1000 milliseconds, for example 20 milliseconds. the

According to the structural design, the best situation may be that the machine, especially the drafting device roller, stops first, and then stops the clamping state of the fiber sliver on one or several corresponding front or upstream roller pairs, and then immediately A trigger pulse is sent to the press roller pair (as a downstream roller pair). When the driving device of the pressure roller pair cooperates with the rollers of the drafting device, the rollers of the drafting device are simultaneously driven by this trigger pulse. What is important in the meantime is that the clamping state of the fiber sliver has been suspended on the roller pair before the pressure roller pair, so that the driven roller pair slides over this roller pair under the fiber sliver. Only in this case will sliver details or end breaks occur between the delivery roller pair and the pressure roller pair. the

After releasing the trigger pulse, it is preferable to wait a short time interval until the roller concerned is repressurized. In this case it is preferable to stop the drafting rollers before and after a sliver detail or fiber sliver break occurs. the

According to another alternative, the associated rollers are decompressed and pressurized during the slow running of the machine. The same goes for the release of the trigger pulse. the

According to a preferred embodiment of the invention, the sliver detail or end break occurs in the range of a defined position between the pair of delivery rollers and the pair of pressure rollers. For example, this position may be on a sliver forming device inserted in the middle, especially a sliver forming device comprising a web nozzle or a web bell or possibly a downstream guide sliver bell, the sliver forming The device turns the fiber web leaving the drafting device into a fiber sliver. At the web nozzle, the fiber sliver or fiber sliver undergoes a cross-sectional compression and is subjected to a friction at its exit. Due to this friction, the fiber sliver or fiber sliver may be elongated. The sliver details are only possible (as the result of the experiment) to be formed in the free travel between the output roller and the calender roller. the

In an alternative design of the invention, the sliver detail is produced in the drafting device while keeping the draft equal, during which the pressure of the pair of intermediate rollers is reduced, so that the clamping state of the fiber sliver is discontinued there, And the output roller pair that pressure does not change continues to clamp and transport fiber sliver. Contrary to current technological developments, the total draft in the drafting unit has not changed. Among them, only the upper roller in the middle of the drafting device can be decompressed and pressurized separately. the

In the drafting unit itself, that is to say, in the front drafting zone or the main drafting zone, fiber sliver breaks are generally not realized, because the trailing end of the fiber sliver in the running direction is thrown into the spinning machine at the output of the drafting unit. Sliver cans are problematic - loose fiber sliver ends can lead to yarn as opposed to fiber sliver breaks occurring a short distance before the calender rollers. In the case of a particular yarn guide design, it may not be possible to rule out the occurrence of fiber sliver breaks in the drafting unit. the

To make full use of the advantages of the present invention, a pressing bar is usually arranged between the middle roller pair and the output roller pair in the main drafting zone, and friction on this pressing bar may cause yarn detail (or yarn breakage). This eliminates the need for specialized equipment to produce sliver details (or sliver breaks). the

What has been said for the first configuration of the invention with regard to pulse width, decompression and pressurization of the drafting unit rollers at rest applies equally to the generation of sliver details in the drafting unit. Particularly preferred is the design of a control system for controlling according to the invention the pressurization and decompression of the top rollers of the relevant drafting device and the drive of the pressure roller pairs. For this purpose, the control system preferably includes a signal from a can fill state detector or a fiber sliver counter at the output of the drafting device. According to this type of signal, the control system can guide the can change if necessary, for which purpose, according to the invention, at first the sliver details or sliver breaks must be generated. Instead of this control system, an adjustment mechanism can also be provided instead to adjust the fineness of the sliver or the occurrence of sliver breaks. the

For fast and accurate switching with high repeatability in the microsecond range, the main motor drive preferentially uses semiconductor contactors with no mechanically moving parts. In addition, the temperature dependence of the switching process present on the mechanical contactor is eliminated. Thyristors or IGBTs are used, for example, as semiconductor contactors. the

It is advisable to provide an electronic memory in which are stored parameters for the formation of sliver details or for sliver breaks from different materials, as well as (distinctive) different characteristic parameters of the same material. When changing the stretched material, the operator can use the keyboard (such as a touch screen) to input the corresponding parameters, and then the control system will obtain the values belonging to the parameters and processed by the control system from the database, and use them to Control of one or more roller drives and roller loads. The control system works with an expert system. In addition, it can be specified that one or more detectors are preset on the machine for automatic material identification, so that the control system can automatically obtain the values from the database without operator intervention. the

Preferably a central electronic control and/or adjustment device is preset, for example in the form of a microcomputer, and the roller pairs, the coiler device and/or the drive for the can change are connected to the microcomputer . The above-mentioned control task of controlling the sliver detail and sliver breakage can also be put into this electronic control and/or adjustment device to complete. As an alternative, a separate calculation device can also be preset to calculate the control value or adjustment value required by the central electronic control and/or adjustment device according to the database and expert system, and transmit it to the central electronic control and/or adjustment device . the

The sliver details (regardless of where they are produced in the drafting device or where they are stored) are preferably conveyed through the coiler device when the drafting device is fully loaded again until the sliver details reach their outlet end. The can change then takes place while the machine is at a standstill or running slowly, while the sliver details continue to be stretched and broken at the opening of the coiler unit. Then, the end of the fiber sliver away from the machine is suspended on the can edge of the filled can, while the end of the fiber sliver close to the machine can be fed into the empty can that is subsequently conveyed. the

In the event of a fiber sliver break between the pair of delivery rollers and the pair of press rollers, the end of the fiber sliver close to the machine must be conveyed by the calender rollers into the coiler unit. For this purpose, calendering rollers must first be prepared for the end of the fiber sliver. An air blowing or suction device is preferably designed for this purpose and can be particularly suitable for being arranged on the fiber sliver forming device. The end of the fiber sliver is given a pulse by the flowing air flow, which transports the end of the fiber sliver through the fiber sliver forming device to the calendering roller, which supports the fiber sliver conveying through the preceding pair of output rollers. When fiber sliver breaks occur in the pulling device. It is best to preset a thread guide that simulates work. the

Description of drawings

Below, the present invention will be further described according to accompanying drawing, wherein:

Figure 1 is a side view of a draw frame representing the current level of technological development represented by a schematic diagram;

Fig. 2 is a drafting device with additional load arm among Fig. 1;

Figure 3 is the outlet of the draw frame in Figure 1 (partial cross-sectional view), but including a first embodiment of the detail of producing a sliver according to the invention; and

Figure 4 is the drafting device of Figure 1 but including a second embodiment for producing sliver details according to the invention. the

Detailed ways

Next, the basic operating principle of a draw frame (as an example of a spinning preparation machine) will be described with reference to FIG. 1 , which schematically shows a side view of the draw frame. According to this example, which represents the state of the art, a plurality of substantially untwisted fiber slivers FB (only shown at the top in the figure) are supplied side by side to the draw frame. It is likewise possible to feed only one fiber sliver FB to the draw frame, the fiber sliver being supplied directly by an upstream card or comber. A bell mouth 12 is arranged at the input of the draw frame for compressing the fiber sliver FB. Alternatively, other compression devices can also be used. After passing through a scanning device 2, 3 as a part of the fiber sliver cross-section measuring device described below, the compressed fiber sliver FB' (consisting of a plurality of individual fiber sliver FB) is transported to the forming and In the drafting device 4 of the core part of the strip machine. The drafting device 4 generally has three drafting units, or more precisely three roller pairs, between which the stretching takes place. These are respectively: a pair of input rollers 5a, 5b, a pair of intermediate rollers 6a, 6b, and a pair of output or delivery rollers 7a, 7b, which in this order respectively rotate at gradually increasing peripheral speeds. The fiber sliver FB' that is formed into a fibrous network and rolled wide in the drafting device is stretched by the rollers to different peripheral speeds, and the degree of stretching is proportional to the peripheral speed. A fiber sliver FB' in the form of a fiber network is a fiber sliver (FB') in the sense of the present invention. the

The pair of input rollers 5a, 5b and the pair of intermediate rollers 6a, 6b form the so-called pre-stretching zone; the pair of intermediate rollers 6a, 6b and the pair of output rollers 7a, 7b form the so-called main stretching zone. On non-speed-regulated draw frames, both pre-stretch and main-stretch are constant during the stretching process. Instead, on speed-controlled draw frames, the adjustment is made by changing the draw height. Therefore on a speed-controlled draw frame not only the pre-stretch but also the main draw can be varied, but the main draw is almost always chosen. The reason for this is that the main stretch is larger than the pre-stretch, allowing more precise adjustments. the

Usually, a pressing rod 8 is also arranged in the main drawing zone, which can change the direction of the fiber sliver FB', so that the fibers, especially the fibers that are no longer clamped between the two roller pairs (so-called floating fibers) play a better guiding role. The drawn fiber sliver FB' is combined by means of a reversing upper roller 9 and a fiber sliver forming device 10, and enters the can at a speed v _L through a pair of press rollers 13, 14 and an arc-shaped fiber sliver path 16 18 storage, wherein the fiber slivers 16 are arranged on a turntable 17 rotating at an angular velocity ω.

On speed-controlled draw frames, the fed fiber sliver FB usually passes through a scanning device placed before the drafting device 4 in order to equalize fluctuations in the quality of the fiber sliver. According to the illustrated embodiment, the scanning device consists of two scanning disks 2 , 3 and is a component part of a fiber sliver cross-section measuring device. The scanning disk 2 is designed to be stationary, while the scanning disk 3 acts on the scanning disk 2 with a certain pressure and can therefore be deflected perpendicularly to its axis of rotation. The offset of the scanning disks 3 represents a dimension of the cross-section of the fiber sliver FB' emerging from the two scanning disks. In the illustrated embodiment, the scanning disk 3 is connected to an inductive detector 20, the output signal of which is in the form of a voltage signal, which is first transmitted to a memory 21, which takes into account the The time difference between 4 and the stroke (FIFO memory=First-In-First-Out memory=first-in-first-out memory), after the time difference, is sent to the analysis and adjustment unit 22. The measurement signals are temporarily stored in the memory 21 so that the evaluation and adjustment unit 22 starts adjustment after a predetermined time has elapsed and after the return stroke determined by the fiber sliver FB' has passed, by changing the pair of intermediate rollers 6a, 6b and, if necessary, the pair of input rollers The peripheral speed of 5a, 5b equalizes the fluctuation of the mass. In the present case, the equalization of the mass fluctuations in the main stretching zone is achieved by varying the rotational speed of a servo drive 23 which generates the controlled rotational speed of the planetary gear reducer 24 . Utilize this starting rotational speed of planetary gear reducer 24 when main motor 25 starts, drive input roller pair 5a, 5b and bottom roller 5a, 6a of intermediate roller pair 6a, 6b. The speed of the bottom roller 7a driven by the main motor 25 remains constant in this example and ensures the production of a precisely calculable fiber sliver. At the same time, the main motor 25 drives the calendering roller 13, and relies on friction to drive the calendering roller 14 to rotate together. the

The upper rollers 5b, 6b, 7b, 9 utilize the pneumatic cylinders 35, 36, 37, 38 shown schematically in the figure to apply pressure to the lower rollers 5a, 6a, 7a to ensure that the fiber sliver FB' is clamped. In the case of the present example, the pneumatic cylinders 35, 36, 37, 38 are controlled by the analyzing and adjusting unit 22 comprising a control system, in order to realize the control of all or individual or pairs of top rollers 5b, 6b, 7b or 9 or Decompression or pressurization of roller combinations. the

In an alternative embodiment shown in FIG. 2, a pneumatically loaded load arm 34 is additionally added, which is arranged on the drafting device 4 and supports the top rollers 5b, 6b, 7b, 9 above it. (Schematic representation). In this example, the load arm 34 can be pulled downwards by means of a hook device 33 connected to a pneumatic cylinder 32, so that the top rollers 5b, 6b, 7b, 9 pressurize the bottom rollers 5a, 6a, 7a. In an embodiment not shown in the figures, the pneumatic cylinders 35 , 36 , 37 , 38 can be dispensed with, instead the pneumatic cylinders 35 , 36 , 37 , 38 are spring loaded. The load arm 34 can also be designed to be spring-loaded. Furthermore, as indicated by the double arrow 34a, the load arm 34 can be swiveled upwards towards the drafting device 4 when the pneumatic cylinder 32 is unloaded. the

In Fig. 3 and Fig. 4, two ways of guiding the separation process of the fiber sliver FB' according to the present invention are shown, on the one hand, the separation is carried out by creating sliver details between the lower output roller 7a and the pair of press rollers 13, 14, on the other hand One aspect is that the separation takes place in the main stretching zone. the

An exemplary embodiment of a fiber sliver forming device 10 inserted downstream of the drafting device is shown in a sectional view in FIG. 3 . In this example, the fiber sliver forming device 10 comprises a web bell 40 with a handle 41 . Therein, a web nozzle 42 is inserted into the central opening of the web bell 40 . The fiber net bell mouth 40 is arranged on the supporting plate 43 and can rotate, wherein a fiber sliver bell mouth support 44 and a fiber sliver bell mouth 45 inserted in the support are provided. One end of the fiber sliver bell mouth 45 is pointed, so that the fiber sliver FB' is sent into the gap between the calendering rollers 13,14. the

To produce the sliver details, the fiber sliver FB' is gripped and conveyed by the calender rollers 13 , 14 , while at least the reversing upper roller 9 is decompressed by means of the pneumatic cylinder 38 controlled by the analyzing and regulating unit 22 . Preferably, at least the top roller 7b and the top rollers 5b, 6b (see FIG. 1 ) are also simultaneously decompressed, so as to prohibit further conveyance of the fiber sliver FB' along the direction of the calender rollers 13, 14 when the sliver details are produced. the

Now explain one by one as follows: the detector 19 measures the rotational speed of the calendering roller 13 and transmits the corresponding information to the analysis and adjustment unit 22 . Reaching the predetermined rotational speed means that the can 18 has been filled and the can change guide fiber sliver separation process can be started. First, the evaluation and control unit 22 triggers a machine stop. Then, the analysis and adjustment unit 22 sends a decompression pulse at least to the pneumatic cylinder 38 of the top roller 9, and if necessary, to the pneumatic cylinder 37 of the top roller 7b, and to the pneumatic cylinders of the top roller 5b, 6b according to the situation. Cylinders 35,36. Correspondingly, at least the pneumatic cylinder 38 and, if necessary, the pneumatic cylinder 37 are also decompressed, as indicated by the upwardly pointing arrow in FIG. 3 . For the sake of simplicity, the other pneumatic cylinders 35 , 36 are not shown in FIG. 3 . the

In the case of loading of the central drafting device with load arm 34 (see FIG. 2 ), as an alternative or in addition, it is also possible to depressurize the pneumatic cylinder 32 controlled by the analysis and adjustment unit 22 , so that all supports are supported on the load arm 34 Upper top rollers 5b, 6b, 7b, 9 are all decompressed simultaneously. the

After such decompression, one or more brief trigger pulses are sent to the main motor 25 which also drives the bottom roller 7a on the draw frame shown in FIG. 1 . It is worth noting that, in the case of the embodiment shown in Figure 1, the input and intermediate roller pairs are also driven simultaneously. Conversely, if a single drive is used, the roller pairs can be disengaged. During the duration of one or more trigger pulses mentioned above, the bottom roller 7a slides under the fiber sliver FB'. But it continues to be conveyed by calender rollers 13,14. This produces a sliver detail DS1 between the delivery roller pair 7a, 7b and the calender rollers 13,14. The place where the sliver detail is produced may also be the input end of the web bell 40, since the fiber sliver FB' is rubbed there and its cohesion is weakened. However, it is also possible for the sliver detail to be produced before the web flare 40, since the fiber sliver FB' gathers on the web flare and the fibers form a stronger bond. However, tests done in each case have shown that the sliver detail is produced in the area behind the output roller pair 7a, 7b. the

Due to the short duration of one or more trigger pulses (preferably in the range of a few milliseconds), the machine is shut down again within a fraction of a second and the drafting device 4 can then be reloaded. The pulse width of the one or more trigger pulses preferably corresponds to the length of the stretched material. For example, the operator enters the average sample length or hand pull length of the material into the control panel 27, and the machine (considering the speed of the material FB' over the time period of producing the sliver detail) calculates the pulse width of one or more trigger pulses. The pulse width should in particular be metered in such a way that, due to such a long pulse, no fiber sliver breaks are produced instead of a desired sliver detail. The control of the pulse duration is preferably carried out via a detector 19 (see FIG. 1). the

According to the embodiment of FIG. 1 , pulse widths for different material values and material parameters are stored in the database 26 . This database 26 accessible by the analysis and adjustment unit 22 can be preloaded on the machine and/or can be entered and supplemented by the operator via the control panel 27 . Furthermore, the evaluation and adjustment unit 22 can calculate a correction of the pulse width as a function of machine-specific and/or environment-specific parameters (eg ambient temperature). the

If the load sensor (not shown in the figure) fails to recognize that the load has no effect within a short time frame, the resulting sliver detail on the web bell 40 will be generated on the correspondingly loaded drafting device 4 . That is, it is conveyed to the back of the calendering rollers 13, 14 all the time, reaching the output end of the fiber sliver road 16. It is then guided to a can change and the sliver detail is broken at the edge of the output end of the coiler unit. the

As an alternative to producing the sliver detail DS1, a fiber sliver break BB can occur between the output rollers 7a, 7b or the reversing upper roller 9 and the calender rollers 13, 14. For this purpose, the pulse width and/or trigger amplitude can be selected correspondingly higher. The end of the fiber sliver remote from the machine is fed by calender rollers 13, 14 or fed into the filled can 18, while the end of the fiber sliver close to the machine is fed into the fiber sliver forming device 10 by an air flow such as a blowing or suction device. , Then enter the gap between the calendering rollers 13,14. the

The situation in which the sliver detail is produced in the drafting device 4 is shown in FIG. 4 . For this purpose, the evaluation and adjustment unit 22 sends a decompression pulse to the pneumatic cylinder 36, and subsequently, the clamping state on the intermediate roller 6b is interrupted (as shown by the released roller 6b and the upwardly pointing arrow in the pneumatic cylinder 36). Like this, the middle roller pair 6a, 6b no longer transports the fiber sliver FB ', as a result, due to the friction between the fibers on the pressure bar 8, the inertia and adhesion of the fiber and due to the input roller pair 5a, 5b and the output roller pair 7a, The difference in speed of 7b produces a sliver detail DS2 in the area of the pressure bar 8 between the two pairs of rollers. The peripheral speed at which the pair of input rollers 5a, 5b and the pair of output rollers 7a, 7b runs does not change compared to the normal stretching process, so that in the drafting unit 4 the total stretching does not change. the

After the sliver detail DS2 has been produced, the top roller 6b is repressed and the sliver detail DS2 in the fiber sliver FB' (as in the previous embodiment) is conveyed to the output of the fiber sliver track 16, where the machine stops , or to slow speed in order to immediately pull out the filled can from the filling position. Correspondingly, the sliver detail DS2 of the fiber sliver FB' breaks at the edge of the fiber sliver exit. If no sliver details are produced, fiber sliver breaks can also occur in the cut-to-end device, depending on the corresponding yarn guidance at the end of the fiber sliver close to the machine in the following roller pair. the

The present invention has been described above on the basis of a speed-adjustable draw frame. However, the invention can also be used without restriction on non-speed-regulated draw frames. Likewise, a single drive design for the main drive 25 and the servo drive 23 can also be realized if the drive arrangement described above is not used. In addition, the calculation function accepted by the analysis and adjustment unit 22 in this paper can also be realized by using a separate calculation unit, and the analysis and adjustment unit 22 obtains the calculation results and sends control pulses to one or several pneumatic cylinders. These control functions can also be performed by a separate control unit, wherein. The analysis and adjustment unit 22 can act as a central control unit. Likewise, there is no need to provide reversing rollers (for example: vertical drafting device), and it is possible to realize the sliver detail or sliver directly between the output roller pair and the pressure roller pair. Break the end, no need to lift and change the top roller. the

Claims (37)

1. A method of guiding a fiber sliver (FB') at the output of a spinning preparation machine, wherein said spinning preparation machine is equipped with several roller pairs (5a, 5b, 6a, 6b, 7a, 7b, 9) drafting device (4), fiber sliver (FB ') is stretched in this drafting device, utilizes pressure roller pair (13,14) to be delivered to having fiber sliver road (16) and The coiler device of the turntable (17), and use the coiler device to throw and store in a tube (18), it is characterized in that the fiber sliver (FB') is clamped and conveyed by a pair of downstream rollers, and At least one pair of upstream roller pairs (6a, 6b; 7a, 7b; 7a, 9) place to stop the clamping state to fiber sliver (FB '), at this moment, fiber sliver (FB ') is in above-mentioned downstream roller pair (7a , 7b; 7a, 9; 13, 14) and said at least one pair of upstream rollers (6a, 6b; 7a, 7b; 7a, 9) between a sliver detail (DS1; DS2) or a broken head (BB). 2. The method according to claim 1, characterized in that, by electronic control, the associated upper roller (6b; 7b; 9) of the upstream roller pair (6a, 6b; 7a, 7b; 7a, 9) ) on the corresponding bottom roller (6a; 7a; 7a) to stop the clamping state on the upstream roller pair (6a, 6b; 7a, 7b; 7a, 9). 3. The method according to claim 1 or 2, characterized in that the sliver detail (DS1) is produced by clamping and further conveying the fiber sliver (FB') on the press roller pair (13, 14) as a downstream roller pair or break (BB), and at least reduce or stop the pressure between the output roller pair (7a, 7b) and/or between the lower output roller (7a) and the reversing upper roller (9), so that the output roller pair Sliver details (DS1) or broken ends (BB) are produced directly in the range between (7a, 7b) and the pressure roller pair (13, 14). 4. The method according to claim 3, characterized in that the pressure of other roller pairs of the drafting device (4) is also reduced or discontinued. 5. The method according to claim 3, characterized in that at least the pressure roller pair (13, 14) is driven briefly out of standstill in order to produce sliver details or end breaks. 6. The method according to claim 3, characterized in that the sliver detail (DS1) or the broken end (BB) is somewhere between the output roller pair (7a, 7b) and the pressure roller pair (13, 14). Friction occurs at the point where the fiber sliver (FB') is stretched apart. 7. The method according to claim 6, characterized in that the sliver detail (DS1) or the broken end (BB) is in a formation between the output roller pair (7a, 7b) and the pressure roller pair (13, 14). The fiber slivers (FB') are stretched apart at the position on the sliver device (10). 8. The method according to claim 1 or 2, characterized in that, by reducing the middle roller pair (6a, 6b) as the pressure on the upstream roller pair, simultaneously use the output roller pair (7a, 7b) with no change in load As the downstream roller pair continues to grip and convey the fiber sliver (FB'), a sliver detail (DS2) or end break (BB) occurs in the drafting device (4) while the stretch remains equal. 9. The method according to the preceding claim 8, characterized in that the sliver detail or end break occurs at a friction point in the drafting device (4) where the fiber sliver (FB') is stretched . 10. The method according to claim 9, characterized in that the sliver details or end breaks are produced on the press bar (8) in the main stretching zone, where the fiber strand (FB') is stretched. 11. The method according to claim 1, characterized in that the drafting device rollers (5a, 5b, 6a, 6b, 7a, 7b, 9) are producing sliver details (DS1; DS2) or broken ends (BB) before and after entering the stop state. 12. Method according to claim 11, characterized in that the drafting device rollers (5a, 5b, 6a, 6b, 7a, 7b, 9) are depressurized and pressurized during standstill. 13. The method according to claim 3, characterized in that one or more triggering pulses of the pressure roller pair (13, 14) are calculated by the analysis and adjustment unit (22) of the spinning preparation machine, for which the operation The person enters a characteristic length of the stretched material as the basis for the calculation. 14. A method according to claim 13, characterized in that the pulsed activation of the press roller pair (13, 14) consists of one or more trigger pulses, each single trigger pulse having a duration of 1 to 100 milliseconds. 15. The method of claim 14, wherein each single trigger pulse has a duration of 15 to 25 milliseconds. 16. The method according to claim 1, characterized in that, in the case of producing a sliver detail, the coiler device causes the sliver detail (DS1; DS2) at the fiber sliver outlet of the fiber sliver track (16) beheaded. 17. The method according to claim 16, characterized in that, in the case of producing a sliver detail, the fiber sliver track (16) of the coiler device is connected to the uppermost sliver reserve position in the can (18) The distance between is enlarged when changing the can, so that the sliver detail (DS1; DS2) breaks at the fiber sliver outlet of the fiber sliver track (16). 18. The method according to the preceding claim 16, characterized in that the pressure of at least one roller pair in the upstream roller pair is recovered after producing a sliver detail (DS1; DS2), the sliver detail (DS1; DS2) being determined by The pair of pressure rollers (13, 14) are conveyed to the exit of the fiber sliver to separate the fiber sliver (FB') on the sliver detail (DS1; DS2) by the subsequent movement of the can. 19. The method according to claim 1, characterized in that the following process: - the spinning preparation machine is stopped for can change, - unloading of the drafting unit (4), - sliver detail (DS1; DS2) generation, - reloading of the drafting unit (4), - the sliver details (DS1; DS2) are fed behind the pair of press rollers (13, 14), - Guidance for can change, separation of fiber sliver (FB'). 20. The method according to claim 19, characterized in that the sliver detail (DS1; DS2) is fed to the output of the fiber sliver track (16). 21. The method according to claim 19, characterized in that the roller pairs (5a, 5b, 6a, 6b, 7a, 7b, 9 ) of pressurization and decompression, and the driving device of pressure roller pair (13,14). 22. The method according to claim 21, characterized in that the analysis and adjustment unit (22) is connected to an electronic memory (26), which can be input and stored with different materials to form sliver details or produce broken ends. parameter. 23. Spinning preparation machine equipped with a drafting device (4) with many roller pairs (5a, 5b, 6a, 6b, 7a, 7b, 9) in which the fiber sliver (FB ') is stretchable, and is also equipped with a pair of press rollers (13, 14) connected in the running direction to compress and transport the stretched fiber sliver (FB'), and is equipped with a fiber sliver path (16) To transport and throw fiber sliver (FB') into the can (18) for storage, it is characterized in that the fiber sliver (FB') is clamped on at least one pair of upstream roller pairs, by reducing the pressure of the roller pair, Can suspend above-mentioned clamping state for a short time, but, fiber sliver (FB ') is clamped and conveyed by a pair of downstream roller pair, and between above-mentioned at least one pair of upstream roller pair and described downstream roller pair in fiber sliver (FB ') Sliver details (DS1; DS2) or end breaks (BB) are produced in FB'). 24. Spinning preparation machine according to claim 23, characterized in that the spinning preparation machine is a drawing frame or a carding machine. 25. Spinning preparation machine according to claim 23 above, characterized in that, after the generation of the sliver detail (DS1; DS2), the pressure of at least one upstream roller pair is re-established, and the sliver detail is produced by the pressure roller pair ( 13, 14) continue to the outlet of the fiber sliver track (16), the fiber sliver (FB') at the sliver detail (DS1; DS2) is separated by the subsequent movement of the can (18). 26. Spinning preparation machine according to claim 23 or 25 above, characterized in that it is provided with an analysis and adjustment unit (22), a pneumatic device (32, 35, 36, 37) for pressurizing or depressurizing the rollers , 38) and the drive (25, 23) for the roller pair, the coiler device and the can change (25, 23) are connected to the analysis and adjustment unit. 27. Spinning preparation machine according to claim 23, characterized in that at least one pair of upstream rollers is a pair of delivery rollers (7a, 7b) of the drafting device (4); the pair of downstream rollers is a pair of pressure rollers (13 , 14). 28. Spinning preparation machine according to claim 23, characterized in that at least one pair of upstream rollers consists of a lower output roller (7a) and a reversing upper roller (9), while the downstream pair of rollers is a pair of pressure rollers (13 , 14). 29. Spinning preparation machine according to claim 27 or 28, characterized in that only the pair of driven pressure rollers (13, 14) can be briefly brought out of standstill in order to produce sliver details or end breaks. 30. Spinning preparation machine according to claim 23, characterized in that sliver details (DS1; DS2) or end breaks (BB) occur in upstream roller pairs (6a, 6b; 7a, 7b; 7a, 9) and downstream roller pairs (7a, 7b; 7a, 9; 13, 14) at the frictional position where the fiber sliver (FB') is stretched apart. 31. Spinning preparation machine according to claim 30, characterized in that the friction point is on the fiber sliver forming device (10). 32. Spinning preparation machine according to claim 31 above, characterized in that the fiber sliver forming device (10) comprises a roller pair (7a, 7b) and a press roller pair (13, 14) between Bell mouth (40). 33. Spinning preparation machine according to any one of the preceding claims 23 to 25, 27, 28 and 30 to 32, characterized in that the fiber sliver (FB') is processed in machine one after a fracture has been produced in the fiber sliver (FB'). One end of the side is conveyed to the coiler device by a pair of pressure rollers (13, 14). 34. Spinning preparation machine according to claim 33, characterized in that one end of the fiber sliver on one side of the machine is transported to the coiler device by the pair of pressure rollers (13, 14) and needs to be blown or sucked. support. 35. Spinning preparation machine according to claim 23, characterized in that the tension is kept equal by reducing the pressure of the middle roller pair (6a, 6b) as the upstream roller pair without changing the applied load The output roller pair (7a, 7b) of the downstream roller pair continues to clamp and transport the fiber sliver (FB'), so that sliver details (DS2) or fiber sliver breaks can be produced in the drafting device (4). 36. Spinning preparation machine according to claim 30 or claim 35, characterized in that the frictional position in the area of the pressing bar (8) is in the main stretching zone. 37. The spinning preparation machine according to claim 23, characterized in that a semiconductor contactor is used to ensure the accuracy of the trigger pulse switch of the downstream roller pair. the

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