Spinning machine and method for operating a spinning machine with a multiple number of spinning stations

Abstract

A method is provided for operating a spinning machine with a multiple number of spinning stations. In the normal case, the individual spinning stations are supplied with a fiber material and produce a yarn. Upon the occurrence of predefined events, yarn production is interrupted at individual or all spinning stations, whereas such spinning stations are, when required, subjected to piecing with the assistance of a piecing process in order to start up yarn production again. The respective piecing is carried out with the assistance of handling tools associated with the spinning machine. The individual spinning stations are classified on the basis of one or more production-related parameters, and that, if more piecing processes are to be carried out at the same time than can be carried out by the handling tools, at least the selection of the spinning station to be subjected to piecing next is carried out under consideration of the specified classification.

Claims

1. A method for operating a spinning machine with a multiple number of individual spinning stations, comprising: during spinning operation of the spinning machine, the individual spinning stations are supplied with a fiber material and produce a yarn; upon occurrence of predefined events, yarn production is interrupted at individual or all of the individual spinning stations; with a piecing process, yarn production is restarted at one or more of the individual spinning stations at which yarn production was interrupted, the piecing carried out with the assistance of handling tools associated with the spinning machine; wherein, for the restarting of yarn production, the individual spinning stations are classified on a basis of one or more production-related parameters and, in the event that more piecing processes are to be carried out that exceeds capability of the handling tools for a given period of time, priority of the spinning stations for piecing is selected by consideration of the specified classification of the individual spinning stations, wherein the production-related parameters include more than an order in which yarn production was interrupted at the individual spinning stations; and one or more of the spinning stations are blocked from the piecing process when one or more of the production-related parameters associated with the blocked spinning stations exceeds a threshold value such that the blocked spinning stations are not included in the priority of the spinning stations for piecing until subsequently released for piecing.

2. The method according to claim 1, wherein, in the event the number of piecing processes to be carried out does not exceed the capability of the handling tools, the priority of the spinning stations for piecing is carried out without consideration of the specified classification of the individual spinning stations.

3. The method according to claim 1, wherein the production-related parameters are determined or calculated for each of the individual spinning stations and include one or more of the following: probability of success of a piecing process at the spinning station; number of past piecing processes begun at the spinning station per unit of time; number of past piecing processes ended at the spinning station per unit of time; time that has elapsed since the interruption of yarn production at the spinning station; time that has elapsed since start or end of a most recently started piecing process at the spinning station; yarn quantity or yarn length produced in the past at the spinning station per unit of time; operating time of selected components of the spinning station; number of piecing processes during production of one yarn package at the spinning station; and cause of the interruption of yarn production at the spinning station.

4. The method according to claim 1, wherein the blocked spinning stations are determined depending on an overall efficiency of the spinning machine.

5. The method according to claim 4, wherein the blocked spinning stations are released for subsequent piecing when the overall efficiency of the spinning machine reaches or exceeds a defined value.

6. The method according to claim 4, wherein the blocked spinning stations are released for subsequent piecing when a number of the piecing processes being carried out reaches or falls below a defined value.

7. The method according to claim 1, wherein the handling tools for carrying out the piecing processes are associated with the spinning stations.

8. The method according to claim 1, wherein one or more service units move back and forth between individual spinning stations for carrying out the piecing processes, wherein movement of the service unit(s) is carried out under consideration of the specified classification of the individual spinning stations.

9. The method according to claim 1, wherein the classification of the individual spinning stations is carried out continuously or on a planned periodic basis.

10. A spinning machine with a multiple number of spinning stations for production of yarn, comprising: each spinning station comprising a spinning unit with an inlet for a fiber material and an outlet for the yarn produced from the fiber material; each spinning station comprising a winding device for winding up the produced yarn and a yarn monitoring unit for monitoring at least one yarn parameter of the yarn leaving the spinning unit; and a control unit configured to operate the spinning machine in accordance with the method of claim 1.

Description

DESCRIPTION OF THE INVENTION

(1) Therefore, a task of this present invention is to improve the described spinning process in such a manner that the efficiency of the spinning machine is improved. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

(2) The tasks are solved by a method and a spinning machine with the characteristics described and claimed herein.

(3) Within the framework of the method in accordance with the invention, it is now provided that, during the spinning operation of each of the spinning stations, the yarn leaving the spinning units of the individual spinning stations is monitored with the assistance of the yarn monitoring units allocated to the individual spinning stations (for example, by means of sensors monitoring yarn in optical or capacitive terms). The monitored yarn parameters may be, for example, the thickness or the hairiness of the yarn and/or the chronological change of corresponding yarn parameters. If one or more yarn parameters deviate from a given target or if specified limits are exceeded, yarn production is interrupted at the respective spinning station. Likewise, it may be necessary to interrupt yarn production at one or more spinning stations for maintenance or repair purposes. After all of these pre-defined events, a piecing process is necessary at the previously stopped spinning station, in order to proceed with yarn production.

(4) In contrast to the state of art, the present invention is distinguished by the fact that the individual spinning stations are classified on the basis of one or more production-related parameters (that is, they are assessed qualitatively), and that, if more piecing processes are to be carried out simultaneously than can be carried out by the handling devices responsible for the piecing (service robots and/or piecing devices associated with the spinning stations, such as suction or blast nozzles), at least the selection of the spinning station of the next piecing process takes place under consideration of the specified classification.

(5) The sequence of the spinning stations for the successive piecing processes is not governed, or at least not exclusively governed, by the sequence in which yarn production was previously stopped at the respective spinning stations. Rather, for the chronological sequence for the piecing processes at the spinning stations, the parameters specified or established for the individual spinning stations are taken into account. The parameters are, as explained in more detail below, factors that are determined individually for each spinning station, and with the assistance of which the individual spinning stations can be characterized with respect to their yarn production behavior and/or piecing behavior. If the parameters are taken into account upon the selection of the spinning station for the next piecing process, the overall time that is required for the piecing of the spinning stations of the spinning machine per hour of operation is minimized, and/or the overall efficiency of the spinning machine can be increased.

(6) As a result, therefore, the sequence of the spinning stations that are successively spun in deviates at least partially from the sequence in which yarn production was previously stopped at the respective spinning stations.

(7) Advantageously, if fewer piecing processes are currently simultaneously carried out than can be carried out by the handling devices, the selection of the spinning station for the next piecing process takes place without consideration of the specified classification. In this case, the piecing processes of the individual spinning stations can be carried out, for example, in the chronological sequence in which yarn production was previously stopped at the respective spinning stations. Thus, the chronological sequence of the spinning stations for the successive piecing processes depends, among other things, on whether, at a specified point in time, more spinning stations require a piecing process than can be carried out by the handling devices provided for this purpose.

(8) In particular, the parameters specified below come into consideration as parameters, whereas one or more of the parameters can be taken into account in the determination of the spinning stations to be successively subjected to piecing. At this point, it must be noted that the sequence is preferably specified by a control unit of the spinning machine or a control unit in operative connection with it, whereas, in the specification, the corresponding parameter(s) is or are taken into account; that is, it/they flows/flow into the mathematical model that is saved for this purpose. Thus, the parameters may directly influence the sequence of the spinning stations for the piecing process. Alternatively, it would also be possible to calculate one or more parameter(s) or one or more additional parameter(s), and specify the sequence on the basis of the parameter(s) obtained in this manner. In any event, the corresponding parameters for each spinning station should be determined separately, in order to be able to undertake a corresponding individual classification of the spinning stations.

(9) The following are possible as parameters: the probability of success of a piecing process at the corresponding spinning station; that is, on average, after how many piecing attempts a successful piecing process succeeds; compared to spinning stations with a relatively lower probability of success, spinning stations with a higher probability of success should preferably be subjected to piecing. number of piecing processes commenced per time unit in the past; that is, how frequently an interruption of yarn production arises at the respective spinning station per time unit; compared to spinning stations with a relatively high number, spinning stations with a smaller number of piecing processes should preferably be subjected to piecing. number of piecing processes completed in the past per time unit, in particular in relation to the number of piecing processes commenced in the past; compared to spinning stations with a relatively low relation, spinning stations with a higher relation should preferably be subjected to piecing. time that has elapsed at the respective spinning station since the interruption of yarn production; this is an indication of the reliability of the spinning station or a measure of the amount of yarn produced per time unit; compared to spinning stations for which a relatively short time has elapsed, spinning stations for which a long period of time has elapsed since the last interruption should preferably be subjected to piecing. time that has elapsed since the commencement or conclusion of the most recently commenced piecing process, whereas compared to spinning stations for which the time period is relatively shorter, spinning stations, for which the corresponding time period is longer should preferably be subjected to piecing. yarn quantity or yarn length produced in the past per time unit; compared to spinning stations with a lower time-related yarn quantity/yarn length, spinning stations with a higher time-related yarn quantity or yarn length should preferably be subjected to piecing. operating time of selected components of the respective spinning station, since the piecing behavior or the production speed of the individual spinning stations often depend directly or indirectly on the operating time; compared to spinning stations, the selected components of which feature relatively longer operating times, spinning stations with shorter operating times of selected components (such as the drafting system rollers or their components or of the yarn formation element of an air jet spinning machine or of the rotor of a rotor spinning machine) should preferably be subjected to piecing. number of piecing processes during the production of a yarn package; this value indicates how often interruptions in yarn production arise, that is, how reliably the corresponding spinning station is working; accordingly, compared to those spinning stations for which, viewed relatively, interruptions frequently arise, spinning stations for which interruptions less frequently arise should preferably be subjected to piecing. cause for the interruption in yarn production; for example, a spinning station, for which yarn production was interrupted based on a short-term variation in thickness, should preferably be subjected to piecing, compared to a spinning station for which a variation in thickness of over several meters of yarn was observed prior to the interruption of yarn production, since, in this case, the unit that supplies fiber material to the spinning unit may not correctly function and may have to be readjusted. number of piecing processes depending on the yarn quantity already produced at the respective spinning station (whereas the yarn quantity produced over a predefined time period is used as the basis).

(10) It is also advantageous if individual spinning stations are temporarily not subjected to piecing, depending on their classification. For example, it would be conceivable to temporarily block spinning stations, for which one or more parameter(s) is(are) outside of defined threshold values, from the piecing process. The removal of the block may take place, for example, after a predetermined time period or manually. Likewise, the blocking of individual spinning stations may take place manually or automatically with the assistance of the control unit, whereas, upon an automatic blocking, a message may be outputted to an operator of the spinning machine (for example, in the form of a visual signal). For example, it would be conceivable not to subject individual spinning stations to piecing for a certain period of time if the number of spinning stations that require piecing simultaneously exceeds a defined amount, whereas, in such a case, forecasts regarding the piecing processes to be expected could be taken into account in a period of time in the future.

(11) It is also extremely advantageous if individual spinning stations are temporarily not subjected to piecing, depending on the overall efficiency of the spinning machine. One dimension for assessing the overall efficiency would be, for example, the yarn quantity or yarn length, produced per time unit, averaged through the spinning stations that are not blocked. If the overall efficiency of the spinning machine decreases over time, individual or additional spinning stations can be blocked from the piecing process. If the efficiency increases over time, individual or all previously blocked spinning stations could be released again for the piecing process.

(12) It is particularly advantageous if the spinning stations that were temporarily not subjected to piecing in accordance with the previous description are subjected to piecing once again, if the overall efficiency of the spinning machine reaches or exceeds a defined value. In other words, there may be a saving of threshold values, upon the exceeding or falling below of which individual spinning stations are automatically blocked from the piecing process or are once again released for it, whereas the selection of the spinning stations to be blocked or once again released is to take place on the basis of the parameters specified above.

(13) It is likewise conceivable toirrespective of a classification that took placeonce again subject individual or all spinning stations to piecing that were previously not subjected to piecing, by means of a corresponding control command, for example, if a batch change is pending (that is, a different type of yarn is to be produced on the spinning machine).

(14) It is advantageous if the spinning stations temporarily not subjected to piecing in accordance with the previous description are once again subjected to piecing, if the number of piecing processes that were actually carried out or were requested by the individual spinning stations reaches or falls below a defined value. For example, a value X (for example, 5), which states that up to X spinning stations could be simultaneously subjected to piecing, could be saved in the control unit. If, for example, the number of spinning stations to be subjected to piecing at a certain point in time is at X+2, 2 spinning stations would be temporarily blocked from the piecing process. If, because of successfully carried out piecing processes, the number falls once again to a value below the specified value X, additional spinning stations that were previously blocked may be subjected to piecing.

(15) It is likewise advantageous if the piecing process is carried out at least partially, preferably exclusively, with the assistance of handling devices associated with the spinning stations. These include, for example, suction or blowing nozzles or mechanically acting devices, such as gripping elements or pairs of rollers, with which the yarn can be guided or transported.

(16) It may also be advantageous if, in carrying out the piecing processes, a service unit (a so-called service robot) that is movable back and forth between individual spinning stations is involved, or if the piecing processes are carried out exclusively with the assistance of corresponding service units, whereas the movement of the service unit takes place under consideration of the specified classification (whereas, of course, multiple service units may also be used). In other words, the service unit(s) does/do not move, or does/do not always move, to the spinning stations to be subjected to piecing, which is closest to the service unit. Rather, one or more of the parameters specified above of the spinning stations to be subjected to piecing are also taken in account, such that the service unit(s) at least partially also subject spinning stations to piecing first that are further away than other spinning stations to be subjected to piecing.

(17) It is advantageous if the classification of the individual spinning stations takes place on a regular basis; that is, in predetermined time intervals. Preferably, the classification takes place continuously. It is thereby ensured that, for example, spinning stations that have a particularly high rate of production or a particularly reliable piecing behavior are preferably subjected to piecing. Since the amounts of the monitored parameters may always change, the piecing priority of the individual spinning stations (that is, what spinning station is preferably subjected to piecing compared to another) may also constantly change.

(18) Finally, the invention relates to a spinning machine with the physical characteristics described above, whereas the spinning machine comprises a control unit or is in operative connection with a control unit that is designed to operate the spinning machine according to the previously described aspects (whereas the aspects may be realized individually or in any combination). In particular, the spinning machine also features sensors, with the assistance of which the parameters considered upon piecing can be determined.

(19) The invention is not limited to the illustrated and described embodiments. Variations within the framework of the patent claims, such as any combination of the described characteristics, even if they are illustrated and described in different parts of the description or the claims.