Method for high-precision thread delivery during winding of a bobbin

Abstract

A method for highly precise thread placement of a thread (1) during the winding of a bobbin (2) comprising the following steps: a) Continuously acquiring a winding angle ϕspool or a precursor value from which the winding angle ϕspool can be calculated, wherein the winding angle ϕspool describes a coordinate (3) of the thread (1) in a circumferential direction (4) on the bobbin (2); b) Calculating a changeover thread guide control angle ϕchanger,control as a function of the winding angle ϕspool and / or the precursor value, wherein the changeover thread guide control angle ϕchanger,control is calculated from the winding angle ϕspool and / or the precursor value taking into account at least one K-value; c) Using the changeover thread guide control angle ϕchanger,control to calculate an axial thread placement target position Ztarget on the bobbin (2);d) Controlling a changing thread guide (5) according to the axial thread placement target position Ztarget for high-precision thread placement at the coordinate described by the winding angle ϕcoil on the axial thread placement target position Ztarget.;

Description

[0001] The invention relates to the thread placement during bobbin winding, in particular during the winding of synthetic threads into so-called cross-wound bobbins, in which the thread wound on the bobbin crosses regularly. To wind such bobbins, a traversing thread guide (also called a traversing device) is typically used, which moves back and forth in a Z direction (the axial direction of the bobbin) according to a specific pattern to control the deposition of the thread on the bobbin.

[0002] When winding bobbins, it is essential to ensure that a stable, uniform bobbin is built. With the cross-wound bobbins mentioned, the problem of so-called "mirror formation" is particularly evident in this context. As the bobbin diameter increases, a mirror formation occurs whenever one or more complete bobbin revolutions occur per double stroke of the traversing device, i.e., when the ratio of the bobbin speed to the double stroke frequency of the traversing device is equal to 1, a multiple, or a fraction. A double stroke is defined as a complete back-and-forth movement of the traversing yarn guide. The frequency at which double strokes are performed is called the double stroke frequency or traversing frequency. The speed of the bobbin can also be referred to as the bobbin frequency or the bobbin rotational frequency.The ratio of the bobbin speed to the double stroke frequency of the traversing device is generally referred to as the "crossing ratio" or "crossing value" K. The spools, often referred to as pattern windings, cause certain disturbances during unwinding. Furthermore, spools vibrate during winding, resulting in unsteady contact between the pressure roller and the bobbin, and ultimately in damage to the bobbin. Spools must therefore be avoided, especially with smooth threads such as synthetic fibers.

[0003] With a so-called precision winding, the bobbin is built at a traversing speed that is directly proportional to the speed of the bobbin. This means that with a precision winding, the crossing ratio is fixed and remains constant throughout the winding cycle, while the double stroke frequency or the traversing frequency decreases proportionally to the winding speed with the bobbin diameter as the proportionality factor. With this type of precision winding, by specifying the winding ratio with the K value, mirror formation is avoided or at least largely reduced. A further development of the precision winding is the so-called stepped precision winding or step precision winding (SPW). It differs from the precision winding only in that the crossing ratio remains constant only during predetermined phases of the bobbin production (also called the winding cycle).From phase to phase, the crossing ratio is reduced in steps by abruptly increasing the traversing speed. This means that with step-precision winding, a precision winding takes place within each phase or step, in which the double stroke frequency or the traversing frequency decreases proportionally with the spindle speed. After each phase, the double stroke frequency is abruptly increased again, resulting in a decreasing crossing ratio. The crossing ratios that must be maintained during the individual phases are calculated and programmed in advance. Typically, there is a predetermined table of crossing values, also called a K-value table, which can be viewed as a type of specification for the construction of the coil or as a type of blueprint for the construction of the coil.

[0004] Such precision windings and step-precision windings are known, for example, from documents DE 198 17 111 A1 and DE 198 35 888 A1. US 2018 / 0162681 A1 also concerns step-precision windings aimed at achieving particularly dense yarn packing. DE 11 2004 000 484 B4 concerns step-precision windings with a focus on yarn guidance at the side parts of the winding body. DE 100 21 963 A1 also concerns step-precision windings with a focus on yarn deposition at the yarn reversal points on the outer edge of the bobbin.

[0005] Mathematically speaking, the basic idea behind precision winding and step precision winding is that the speed of the coil n coil, or the frequency of the coil rotation ( f coil) is in a fixed ratio to the required transverse movement of the yarn guide. The inverse of the time until the yarn guide completes a complete movement from the left to the right edge of the bobbin and back again is called the traversing frequency or double stroke frequency. f Changier The fixed ratio of the frequency of the coil f coil to the double stroke frequency or traversing frequency f Changier is determined depending on the current coil circumference or the current value of the coil thickness D coil This results in the so-called K-factor, which defines the ratio of the coil frequency to the double stroke frequency or traversing frequency as follows: K D Spule = f Spule f Changier

[0006] Change in the frequency of the coil f coil or the speed of the coil n coil are usually characterized by a constant thread speed v threadThe thread speed is usually predetermined in devices for winding bobbins, for example by an upstream machine for producing, processing or finishing the thread for a constant thread speed v thread Against this background, it is clear that with increasing thickness of the coil D coil the speed n coil, or the frequency f coil must be reduced in order to achieve the desired constant circumferential speed and thus the desired thread speed on the spool surface even with spools with a larger diameter v thread Since the K-factor only depends on the thickness of the coil D coil can be determined at a constant thread speed or circumferential speed v Faden = π ⋅ D Spule ⋅ f Spule = konst . the thickness of the coil D coil directly from the speed of the coil n coil, f coil so that in this case the K-factor can only be determined by f coil is set and the double stroke frequency or traversing frequency f Changier to f Changier = f Spule K f Spule The K values ​​that prevent the formation of mirrors are usually determined from a K-value table described above in the stepped precision winding. The K-value table is preferably designed as a type of look-up table and is designed to be calculated stepwise depending on the thickness of the coil. D coil or the speed of the coil n coil, f coil to return the respective valid K-value, so that the set ratios of f coil to f Changier the critical mirror formation is prevented.

[0007] A major technical challenge in the production of precision windings and step precision windings is that the stepwise adjusted ratio of the two frequencies K f Spule = f Spule f Changier must be adhered to exactly in order to permanently avoid the formation of mirrors.

[0008] The speed of the coil n coil, f coil oscillation frequency to be set in the system f Changier should regularly be error-free. Tolerances for this ratio are usually in the order of 10 -5< Hz = 0.00001 Hz and smaller. In order to maintain such tolerances, a high level of speed accuracy is required, which is accompanied by immense effort in the recording of f coil and the setting of f Changier is connected.

[0009] It is the object of the invention described here to provide a new solution to this problem, which in particular has a considerably increased tolerance to inaccuracies in the metrological detection of variables and in the adherence to target parameters in the control (in particular in the control of the traversing thread guide) and at the same time produces high or even higher quality of the bobbins.

[0010] These objects are achieved with a method according to the features of patent claim 1 and a control device according to the features of patent claim 8. The dependent claims and the description explain particularly preferred embodiments.

[0011] This describes a method for high-precision thread placement of a thread when winding a bobbin, comprising the following steps: a) Permanent recording of a winding angle φ spool or a precursor value from which the winding angle φ spool can be determined, wherein the winding angle φ spool describes a coordinate of the thread in a circumferential direction on the spool; b) Calculating a traversing thread guide control angle φ traversing, control as a function of the winding angle φ spool and / or the precursor value, wherein the traversing thread guide control angle φ traversing, control is calculated from the winding angle φ spool taking into account at least one K value; c) Using the traversing thread guide control angle φ traversing, control to calculate an axial thread deposit target position Z target on the spool; d) Controlling a traversing thread guide according to the axial thread deposit target position Z target for high-precision thread deposit at the coordinate described by the winding angle φ spool on the axial thread deposit target position Z target.

[0012] The core of the innovative method described here is the newly introduced parameter of the winding angle φ coil in step a). This parameter is ultimately an angular value in the circumferential direction of the coil, which follows the course of the thread wound on the coil over the entire structure of the coil and with which any coordinate of the thread on the coil can ultimately be precisely described. This parameter φ coil can be specified in different units, for example in angular degrees, where one revolution of the coil corresponds to 360° (angular degrees) and, for example, 3 revolutions 1080° (angular degrees), or in radians, where one revolution of the coil corresponds to the value 2*π and, for example, 3 revolutions 6*π. However, the parameter φ coil can also be defined such that one revolution of the coil corresponds exactly to an increase of the parameter by the value 1, in which case half a revolution would correspond to the value 0.5, for example.

[0013] The coordinate does not correspond to the length of the thread at the deposition position, because the length of the thread per wrap varies depending on the thickness of the spool (D spool) and the K value. Rather, the coordinate describes a position of the thread that can be uniquely described by the winding angle (φ spool). The thickness of the spool and the K value can be specified for each thread coordinate that can be described by the winding angle (φ spool).

[0014] In connection with the parameter of the winding angle φ coil, it is crucial that this parameter is not reset during the winding process of the coil, but continuously increases during the entire winding process.

[0015] The coil winding angle φ can be measured in a variety of ways, for example, using a counter to count the coil's revolutions or partial revolutions, or similar devices. The following examples describe these in more detail.

[0016] Within the scope of the method, it is not necessary for the winding angle φ bobbin to actually be determined explicitly; rather, it is also possible to simply determine a precursor value, which can be used to calculate the winding angle φ bobbin. This can then be used in the process step b) explained below to calculate the traversing yarn guide control angle φ traversing, control. It is important that at least the precursor value corresponds to the basic idea that an absolute coordinate of the yarn can be described here, and not just a speed of the bobbin and / or the yarn during winding.

[0017] In step b), a so-called traversing yarn guide control angle φ traversing, control is calculated based on the winding angle φ spool. This new parameter is used to control a traversing yarn guide, and this parameter also increases with the winding angle φ spool throughout the entire winding process. When calculating the traversing yarn guide control angle φ traversing, control, the known K values ​​already explained in the introduction, as well as other input variables if necessary, can also be taken into account. The ways in which this can be done are explained in more detail below.In particular, due to the changed K values ​​when producing a step precision winding, φ traversing control does not run continuously proportional to the winding angle φ bobbin, but changes in the rule for calculating the traversing thread guide control angle φ traversing control from the winding angle φ bobbin can occur, taking into account the K value and, if applicable, other input variables.

[0018] Because the method with the winding angle φ bobbin and the traversing thread guide control angle φ traversing, control does not take into account the speeds of the winding process and the traversing process, but rather considers infinite parameters, any coordinate of the wound thread on the bobbin can be described. Using the winding angle φ bobbin, any coordinate of the wound thread can be described precisely, and it is thus even possible to build a type of model of the entire bobbin with which every intersection point at which threads from different windings of the bobbin cross can be precisely predicted and described.

[0019] In step c), the traversing yarn guide control angle φ traversing,control is used to calculate an axial yarn deposit target position Z target on the spool. The axial yarn deposit target position Z target as well as an actual axial yarn deposit position Z actual defined below do not necessarily have to correspond 1:1 to the position of the yarn on the spool. The mechanics at work when the yarn is wound can lead to differences here, which can be caused, for example, by the yarn running behind the traversing yarn guide or by the yarn overswinging slightly when the direction of movement of the traversing yarn guide changes. Such effects are preferably neglected here. It is assumed that the axial yarn deposit actual position Z actual is set by the traversing yarn guide.Step c) also includes the variant that the axial thread deposit position Z target is calculated in the form of a traversing thread guide target angle φ traversing,target, which defines a desired axial thread deposit target position Z target. A traversing thread guide target angle φ traversing,target is therefore a special case of Z target. Traversing thread guide target angle φ traversing,target as Z target come into consideration, for example, when traversing thread guides are designed as traversing thread guide arms that can be pivoted at an angle around a pivot point or when traversing thread guides are designed as so-called bi-rotors, in which the traversing movement is carried out by a rotary drive that is converted by a gear into a linear traversing movement in the Z direction.

[0020] When calculating the axial yarn deposit target position Z target, there are basically two different variants. In fact, the length of the spool is limited in the axial Z direction, and a traversing yarn guide for depositing the yarn moves back and forth within this limited range. For this reason, the axial yarn deposit target position Z target can be understood as an absolute position of the yarn at the coordinate of the yarn in the Z direction described by the winding angle φ spool. With each back and forth movement of the traversing yarn guide, the axial yarn deposit target position Z target is then reset and this does not increase with the winding angle φ spool and the traversing yarn guide control angle φ traversing,control. However, it is also possible to view the movement of the traversing yarn guide as a movement that continues (infinitely) during the winding process.With this approach, for example, the regular reversals of the movement of the traversing yarn guide for depositing the yarn are mentally ignored and the linear movements of the yarn guide are viewed as continuing indefinitely. In other words: With this approach, the total distance traveled by the yarn guide is considered, summed up, or integrated. Such a view of the axial yarn deposit target position Z target is equivalent, for example, if the traversing yarn guide is driven by an eccentric that executes a rotational movement and this is converted into an axial traversing movement by an eccentric element of the eccentric to control the traversing yarn guide. The axial yarn deposit target position Z target can then be used to describe the (indefinitely) continued rotational movement of the eccentric drive.Such design variants can be realized in particular with the bi-rotor described above, in which (as mentioned above), for example, Z soll can be defined as φ traversing, soll.

[0021] A conversion of the (infinitely) continued or increasing parameter φ traversing,control to Z desired as a parameter that describes the traversing movement (e.g., φ traversing,setpoint) can be performed, for example, using a modulo operation, in which the input value φ traversing,control is divided by a parameter value, leaving a remainder that designates the output value Z desired or φ traversing,setpoint, or an intermediate variable for calculating these values. According to step d), a traversing thread guide is now controlled to perform the thread deposit according to the axial thread deposit target position Z desired.

[0022] The method is particularly advantageous if the winding angle φ coil describes the coordinate of the thread in the circumferential direction on the coil, starting from a winding start of the thread on the coil and continuing over all windings of the coil.

[0023] The winding angle φ coil therefore preferably starts with a starting value (for example with "0" at the beginning of the winding process) and increases from this value. For example: If the winding angle φ coil is specified in radians, the winding angle φ coil after 100,000 revolutions of the coil during winding would have a value of 2*π* 100,000.

[0024] It is also advantageous if a deposit of the thread at the target position Z target is defined via a traversing thread guide target angle φ traversing, target, which describes an angle of a traversing thread guide which causes a thread deposit at the axial thread deposit target position Z target.

[0025] As already described above, various designs of traversing yarn guides are possible. Commonly used traversing yarn guides are arms suspended in an angular range that guide the yarn, as already mentioned above. Another variant can be a slider that can be moved purely linearly along the Z-direction, which can also be driven by a linear drive if necessary. Also possible are traversing yarn guides with so-called bi-rotors, which were also mentioned above.

[0026] It is also advantageous if input variables that can also be used to determine the angular velocity of the coil during winding Ω coil are used to determine the winding angle φ coil or the precursor value in step a). Such input variables are, in particular, measured values ​​that can also be used to determine the angular velocity Ω coil, such as measured times for defined numbers of revolutions / windings of the coil or measured changes in the winding angle φ coil (e.g. dφ coil or Δφ coil as possible precursor values), etc. In mathematical terms, the determination of the winding angle φ coil can be understood as the integration of the angular velocity of the coil during winding Ω coil.

[0027] As already explained above, it is common practice in winding devices for the described method to monitor the speed of the winding process, in particular the angular speed of the bobbin during winding Ω bobbin, whereby this parameter was traditionally used to set the double stroke frequency or traversing frequency or the speed of the traversing thread guide in accordance with the specifications described above. Here, it is now proposed to use the angular speed of the bobbin during winding Ω bobbin or the input variables usually used to determine the angular speed in order to determine the winding angle φ bobbin or the traversing thread guide control angle φ changier,steuer by integration. This makes it possible to use the usual sensors to carry out the described method (in particular step a) of the described method).

[0028] Integration is preferably performed over the time elapsed during winding the coil. In some embodiments, integration is also possible over another parameter, for example, the incremental number of windings, which can be determined using a winding counter or a pulse counter, which can count the number of revolutions of the coil and / or the number of windings produced on the coil.

[0029] It was already explained above that instead of the winding angle φ coil in step a), a precursor variable of this winding angle can also be determined, which can then also be used in step b) to determine the traversing thread guide control angle φ traversing,control. In process variants, it is possible for this precursor variable to be a variable that still has to be integrated over time or another continuous parameter (such as the winding counter n coil) in order to arrive at the winding angle φ coil. Such a precursor variable can be determined, for example, using a pulse counter or an incremental encoder. Such an incremental encoder is set up to measure an increment of the winding angle (a change in the winding angle) and to provide it as a variable. It is then preferred that an integration takes place as part of the determination of the traversing thread guide control angle φ traversing,control in step b).

[0030] Furthermore, it is advantageous if a winding counter is used to determine the winding angle φ coil in step a), which indicates the number of windings on the coil.

[0031] Such a winding counter can, for example, be implemented by a switch that is activated once with each revolution of the coil. Such a switch can be electronically connected to a counter that continuously counts up the number of windings. It is particularly preferred if such a winding counter n coil combined with a recorded and integrated angular velocity Ω coil of the coil during winding is used to determine the winding angle φ coil.

[0032] It is also advantageous if the angular velocity Ω coil of the coil during winding of the coil depends on the increasing thickness of the coil D coilis adjusted in such a way that a constant thread speed is achieved in upstream processing steps of the thread.

[0033] It was already indicated above that a constant yarn speed is desirable, particularly due to other boundary conditions during the winding process. Adjusting the angular velocity Ω coil to achieve a constant yarn speed despite an increasing coil thickness D coil causes difficulties in the conventional method for controlling the traversing yarn guide. These difficulties are better solved in the method described here because, by switching from speeds to absolute angular values, inaccuracies or tolerances in the speed detection are less significant for the accuracy of the yarn placement.

[0034] As already explained, when calculating the traversing yarn guide control angle φ traversing, control from the winding angle φ bobbin, at least one K value is taken into account. The K value is constant for at least a time interval during bobbin winding; this determines the structure of the crossing points of the yarn windings.

[0035] As already mentioned above, parameters are taken into account when calculating the traversing yarn guide control angle φ traversing,control in step b). To achieve a so-called precision winding, it is important that such a parameter (K ​​value) remains constant for at least a certain time interval during the winding of the bobbin. Preferably, such a time interval lasts for the entire winding period.

[0036] It is particularly advantageous if a plurality of K values ​​are used when winding the coil, which are determined according to a predetermined scheme depending on at least one of the following parameters: Winding angle φ coil ; angular velocity Ω coil ; speed of the coil n coil or frequency of the coil f coil ; or thickness of the coil D coil .

[0037] Each K value leads to a specific coil step, in which a specific coil winding shape is achieved. By using multiple K values ​​and gradually alternating between these K values, a coil structure is created that is referred to as a stepped precision winding. The so-called stepped precision winding has already been explained in more detail above.

[0038] Preferably, K values ​​for determining the traversing yarn guide control angle φ traversing, control in step b) are set externally to the process (i.e. outside the process described here). The process described here is supplied with a K value table with K values, preferably as a specification for building a bobbin. The process described here then ensures that this specification for building a bobbin is adhered to during winding. The correct K value for each winding stage can be selected using a suitable parameter. It is usually advantageous if the K value is selected using the (existing) diameter of the bobbin D bobbin or the speed of the bobbin n bobbin.

[0039] It is also advantageous if, in step c), the traversing thread guide is controlled by a controller, whereby an existing thread deposit position Z is monitored and the control difference ΔZ = Z target - Z is calculated as the input variable for the controller.

[0040] An existing thread deposit position Z is can also be referred to as the "actual" thread deposit position. The existing thread deposit position Z is preferably detected using a sensor. As already indicated above, deviations can still occur between the existing thread deposit position Z is used for the method described here and the actual thread deposit situation on the bobbin. These deviations are caused by the mechanics of the thread deposit with the traversing thread guide. Such deviations can occur, for example, because the thread lags behind the traversing movement and / or overshoots when the direction of the traversing movement changes. The control deviation ΔZ describes an error in the thread deposit position. Using the method described, the error in the thread deposit position can actually be limited to ΔZ. Inaccuracies in the thread deposit are thus fully detected and can be corrected with the controller.This is possible because Z target is a fully calculated value that initially exhibits no systematic error. This is a fundamental difference from state-of-the-art methods for controlling traversing, in which inaccuracies can occur due to the recording of the speeds of the winding movement and the traversing movement that are unavoidable or only with great effort and / or can be reduced. Such inaccuracies can lead to unknown deviations between Z target and Z actual, which can only be avoided by very precise adherence to speeds.

[0041] The use of a controller to control the traversing yarn guide position based on the calculated value Z is therefore a new approach that can lead to a significantly improved quality of the yarn deposit during winding and / or can be used to reduce the measurement effort in the accuracy of speed monitoring.

[0042] Also to be described here is a control device for controlling a traversing thread guide of a device for winding bobbins, set up to carry out the described method, comprising at least a first control module for calculating the traversing thread guide control angle φ traversing, control based on a detected winding angle φ bobbin and a second control module for calculating an axial thread deposit target position Z target using the traversing thread guide control angle φ traversing, control.

[0043] The control unit is preferably a module that can be used in a winding device to control the traversing yarn guide. The control unit is preferably configured to receive K values ​​(in particular a K value table) and to take them into account when controlling the traversing yarn guide. For this purpose, the control unit preferably has an input to which the K value table can be transmitted. In other embodiments, it is also possible for the control unit to have an input via which the "current" K value to be used is specified to the control unit. Optionally, the control unit can have an output at which a selection parameter is provided, with which the "current" K value can be selected externally by the control unit, by another control unit, or by a higher-level control unit.

[0044] It is particularly advantageous if the control unit additionally has a controller which is designed to receive an existing thread deposit position Z and to generate an output signal for the regulated control of the thread deposit based on the existing thread deposit position Z and the desired thread deposit position Z.

[0045] It is also advantageous if the control unit has a common timer which is used for detecting the winding angle φ of the bobbin, with no further timer being required to control the traversing thread guide.

[0046] In addition, a coil manufactured according to the method and whose structure corresponds to a step precision winding is described here.

[0047] Bobbins wound using the described method are characterized in particular by particularly precise adherence to the desired thread placement position Z desired with Z actual. The accuracy of the thread placement position Z actual results in particularly smooth end surfaces of the wound bobbin and a uniform surface of the bobbin.

[0048] The coil is particularly advantageous if tolerance deviations between an axial thread deposit actual position Z is and an axial thread deposit target position Z target are evenly distributed along the thread and the winding angle φ coil and in particular no proportionality occurs between the winding angle Ω coil and such tolerance deviations.

[0049] The method described makes it possible in particular to ensure that the error in the actual axial yarn deposit position Z can be fully taken into account in the form of ΔZ, and that this error can be used to ensure controlled deposit of the yarn. With previously conventional methods for controlling the traversing speed, small deviations in the time and speed recording could lead to systematic errors that could build up during the winding process (particularly while maintaining a K value). Such errors can no longer occur. A fundamental divergence between the traversing position and the angular position during winding can no longer occur if the control described here is carried out with ΔZ as the input variable of the controller.Therefore, a relatively narrow tolerance band for errors in the axial thread placement can be specified, which is used quite evenly over the entire winding angle φ coil for all coordinates of the thread.

[0050] The invention and the technical environment are explained in more detail below with reference to the figures. The figures show preferred embodiments, to which the invention is not limited. It should be noted in particular that the proportions shown in the figures are only schematic. They show: Fig. 1: a schematic diagram of thread deposit with a thread guide on a spool; Fig. 2: a schematic diagram of mirror formation when winding spools; Fig. 3: a qualitative representation of the stepwise variable K value as a function of the spool speed; Fig. 4: the angle φ spool and Z as a function of time t according to the prior art; Fig. 5: a system comprising a controller for the method described here and the path to be controlled; Fig. 6: the angle φ spool and Z target ≈Z actual as a function of time t according to a variant of the described method;

[0051] Fig. 1 and Fig. 2each show schematic diagrams of the thread deposit with a traversing thread guide 5 when winding a bobbin 2. Various things must be taken into account when winding the bobbins 2. A special feature is the so-called mirror formation, in which two thread sections of the thread are deposited one on top of the other at the same location at different times. The thread deposit can be described with a thread coordinate 3, which describes the deposit point of the thread in the circumferential direction 4 of the bobbin with the winding angle φ bobbin starting from a winding start 6. The winding start 6 can be understood as the start of the wound thread 1 on the bobbin 2. The winding angle φ bobbin or an incremental of the winding angle dφ bobbin can be determined with a rotation sensor 8, which can comprise a winding counter and / or an incremental encoder and / or a combination thereof.In the axial direction of the bobbin 2, the thread coordinate 3 can be described by Z, where Z (depending on the point of view) can be determined directly on the bobbin 2 or on the traversing thread guide 5. In . Fig. 1 and Fig. 2 In each case, the diagonal path of thread 1 from the traversing thread guide 5 to the bobbin 2 indicates that the thread 1 follows the traversing movement of the traversing thread guide 5. This can lead to deviations depending on whether Z is determined on the bobbin 2 or on the traversing thread guide. The closer the traversing thread guide 5 is arranged to the bobbin 2, the smaller this effect is.

[0052] The Fig. 1 shows a coil in which a first winding layer 15 of windings 7 is being created using the thread 1. Fig. 2shows a situation in which a second winding layer 16 of windings 7 of the thread 1 is created on the first winding layer 15. With the traversing thread guide 5, Z actual of the thread deposit is set according to Z target.

[0053] The Fig. 2 shows the mirror formation in a very simplified way using an example. In the second winding layer 16 marked with dots, the thread 1 is deposited exactly on the windings 7 of the first winding layer 15. In the Fig. 2 This indicates a situation of mirror formation. Fig. 2 The mirror formation indicated above results in technical problems, as threads lying directly on top of or next to each other tend to stick together, which in turn leads to problems when unwinding, the so-called pulling off the spool, and must therefore be avoided at all costs. Fig. 2is a highly simplified schematic representation of the problem of mirror formation. In actual designs, the thread runs obliquely in all windings 7. Intersections of threads from different windings occur regularly.

[0054] As already indicated above, the Fig. 2 The described mirror formation can be avoided by precisely adhering to K-values. A K-value table, such as can be used to design a step-precision winding, is given in Fig. 3 shown schematically. K values ​​are plotted on the vertical axis, which change gradually depending on certain parameters (here, speed n coil or frequency f coil of the coil).

[0055] Fig. 4shows the winding angle φ coil (t), which increases continuously as a function of time during winding of the coil. The winding angle φ coil (t) is shown here as a continuously increasing value, which also represents a constant speed or angular velocity Ω coil The actual situation is somewhat more complex, especially when the thickness of the coil D coil changes as a result of the formation of additional windings during winding. In this respect, this representation is in Fig. 4 only schematically, In fact, the winding angle φ coil (t) will increase more and more slowly with increasing time due to the increase in the thickness of the coil D coil.

[0056] Fig. 4also shows the thread deposit position Z(t) during bobbin winding—also schematically depicted as an infinitely continuous parameter that increases continuously and proportionally with the winding angle. Such a description of the thread deposit position is conceivable, for example, if the actual back-and-forth movement of the traversing thread guide is expanded, so to speak, and viewed as an infinitely continuous movement in only one direction. Technically, this corresponds, for example, to variants in which the traversing movement of the traversing thread guide is generated by an eccentric, which executes a continuously rotating movement, which is then converted into a traversing movement.In particular, the conditions arising during the production of precision step windings are more complex, especially when the change in the speed of the bobbin results in a different proportionality factor between the two angle changes (bobbin to thread deposition) (change in the K value). This has been simplified in . Fig. 4 φ coil (t) is drawn as a straight line. Since Ω coil decreases with increasing coil diameter, this representation is simplified and thus only applies to short time intervals of the winding process in which the thickness of the coil D coil does not increase significantly.

[0057] According to the Fig. 4 It should be indicated that Z(t) can only be achieved by precisely maintaining the speed when winding speed Ω Sinkor the speed V is maintained. There is no direct calculated relationship between φ coil (t) and Z(t), but only an indirect relationship through which the respective maintenance of the angular speed of the coil Ω coil and the traversing speed V resulting from the K value, which is kept constant here.

[0058] Fig. 5shows a control unit 10 for carrying out the method described here. The control unit 10 is shown with the control system 21 (formed by the traversing yarn guide 5 and an actuator 18 for moving the traversing yarn guide 5 and, if necessary, a sensor 19 for monitoring the position of the traversing yarn guide 5). The control unit 10 and the control system 21 together schematically form a device 11 for carrying out the method described here. As already indicated above, additional mechanical effects can occur during the deposition of the yarn, such as the trailing of the yarn and the overshoot of the yarn. These effects are shown in the illustration in Fig. 5 have been neglected and are of secondary importance for the functioning of the method and control unit described here.

[0059] The control unit 10 comprises various modules, which may also be implemented with separate hardware, but which are preferably only simulated in software and may also be fully or partially integrated into one another. There is a first control module 12 for determining φ Changier control and a second control module 13 for determining Z is to be based on φ Changier control .

[0060] In preferred embodiments, the control unit 10 can additionally comprise a control value generator 17 for generating the control difference ΔZ = Z target - Z actual, as well as a controller 9. Based on ΔZ or based on Z target and Z actual, the controller 9 generates an output signal 14, which serves as an input signal for the actuator 18 for driving the traversing yarn guide 5. All components of the control unit 10 are indicated here by a dashed line. The components of the control value generator 17 and the controller 9, which are optionally integrated into the control unit 10, are shown separated here by a dash-dot line.

[0061] Here, process step a) is shown as an example, with which the winding angle φ coil or a change in the winding angle dφ coil is detected. This can be done with the schematically indicated rotation sensor 8. Subsequently, dφ coil or the winding angle φ coil is used to determine the traversing yarn guide control angle in step b). φ Changier control to be calculated. K values ​​are also taken into account, which originate from a K value table 23 and which are preferably defined outside of the control unit 10 and made available to the control unit via a signal input 22. Optionally, the first control module 12 can record or receive additional input variables 20, particularly for carrying out method step b). For example, the following additional input variables can be recorded: Winding angle φ coil ; angular velocity Ω coil ; rotational speed of the coil n coil or frequency of the coil f coil ; or thickness of the coil D coil .

[0062] The one in the right part of the Fig. 5 The control loop shown, consisting of the controller 9, the controlled system 21 and the control value generation 17, will always contribute to the fact that the control difference ΔZ = Z setpoint - Z actual is eliminated and that no erroneous angle errors accumulate.

[0063] In contrast to the previous solution, in which a very precise adherence to the specified speed setpoints is achieved only by the angle error (which corresponds to the control difference φ Changier should - φ Changier isIf the angle (Z or Z setpoint - Z is equivalent) is moving away very slowly, the method described here can achieve (theoretically) precise control with respect to possible angle errors. In any technical implementation of a control loop, the instantaneous actual value always fluctuates around the setpoint. Should a noticeable control deviation occur, the controller and actuator would always influence the oscillation in such a way that this control deviation is reduced or even eliminated.

[0064] While maintaining the proven K-value, the new solution aims to increase the precision of the thread placement and at the same time reduce the immense effort involved in recording and adjusting the speeds or frequencies f coil and f Changier At the same time, the winding process is described in detail, which in turn enables easy quality control. The new core idea here is not to rely on temporary speed values ​​(Ω = Δ φ S pule / Δ t ) but rather the absolutely continuous angle values φ coil and thus to regulate the axial thread deposition target position Z target.

[0065] The angular paths of the coil φ coil and the oscillating system Z can be measured, for example, with an initiator or an incremental encoder according to the current technical implementation. With these measuring methods, each new pulse signals that the angle has changed by dφ coil or Δ φ coil increment has continued to rotate. The incremental encoder can, for example, be a winding counter that counts each individual revolution of the coil or partial revolutions of the coil.

[0066] The individual pulses received from the initiator or incremental encoder are then summed up in the processor of, for example, a QEP unit, which ensures that no angle information is lost and that the correct angular path is always φ coilis present.

[0067] The drive of the traversing unit, which is operated via a controller / inverter, can be influenced in terms of torque or speed, so that Z is can be influenced and the desired thread placement position Z should be tracked and maintained.

[0068] In the Fig. 5In addition to the first control module 12 for carrying out method steps a) and b) and for determining the traversing thread guide control angle φ traversing,control, the second control module 13 is shown in which the conversion of the traversing thread guide control angle φ traversing,control into the target value for controlling the thread deposit position Z target represents. This module can, for example, be a proportional conversion from φ traversing,control to Z target (in design variants, Z target is the angle φ traversing,control). In design variants, this module can also convert the (infinitely) permanently increasing traversing thread guide control angle φ traversing,control into a limited value which, for example, describes the coordinate Z in the deposit area of ​​the thread on the spool. This conversion can, for example, be carried out using a modulo operation.

[0069] Fig. 6shows the continuously increasing angle φ spool and the thread deposition position Z soll ≈Z ist as a function of time t as it can be controlled with the method described here.

[0070] This shows Fig. 6 the situation that occurs at a constant K value. Fig. 6 shows the situation with a coil that is designed as a precision winding. Z target depends directly and mathematically exactly on φ coil. Therefore, no error can occur between φ coil and Z target. Z actual is determined according to the Fig. 5 The system structure shown is monitored with a sensor and can thus be adjusted with a controller according to Z target. A divergence of φ coil or Z target and Z actual is therefore technically impossible, so that the desired precision is achieved here. The new method controls the difference between the setpoint and actual values, thereby permanently preventing the angle value from "running away." This results in greater precision in thread placement, which also effectively prevents mirroring. (The previous method required considerable effort to achieve high precision in speed control, so that the angle value between the setpoint and actual values ​​only drifts away slowly. There is currently no measurement of the angle difference or even control based on the angle difference; rather, the previous solution with regard to the angle value is open-loop control rather than closed-loop control!) The technical effort and thus the costs are significantly reduced, since the previously high demands on speed control (converter, data acquisition, controller) are significantly reduced by controlling the angle value.Recording the absolute continuous angle values ​​of the bobbin and the traversing yarn guide control angle while simultaneously taking into account an absolute time (each beginning with the winding process) allows for a very detailed description of the realized bobbin structure and thus facilitates simple quality control. For example, each wound bobbin could be provided with an associated data file from the winding process. List of reference symbols

[0071] 1Thread 2Spool 3Coordinate 4Circumferential direction 5Traversing thread guide 6Start of winding 7Winding 8Rotation sensor 9Controller 10Control unit 11Device 12First control module 13Second control module 14Output signal 15First winding layer 16Second winding layer 17Control value generation 18Actuator 19Sensor 20Input variables 21Control system 22Signal input 23K value table φ spool winding angle φ traversing,control traversing thread guide control angle Z setpoint axial thread depositing setpoint position φ traversing,setpoint traversing thread guide setpoint angle Ω spool angular speed of the spool n spool speed of the spool D spool thickness of the spool KK value f spool frequency of the spool Z actual present axial thread depositing actual position V traversing speed

Claims

1. Method for the high-precision thread deposit of a thread (1) when winding a spool (2), comprising the following steps: a) Permanently detecting a winding angle φspool or a precursor value from which the winding angle φspool can be calculated, wherein the winding angle φspool describes a coordinate (3) of the thread (1) in a circumferential direction (4) on the spool (2); b) Calculating an alternating thread guide control angle φalternating,control in dependence on the winding angle φspool and / or the preceding value, wherein the alternating thread guide control angle φalternating,control is calculated from the winding angle φspool and / or the preceding value, taking into account at least one K value; c) Using the oscillating thread guide control angle φalternating,control to calculate an axial thread deposit target position Ztarget on the spool (2); d) Controlling a alternating thread guide (5) according to the axial thread deposit target position Ztarget for high-precision thread deposit at the coordinate described by the winding angle φspool on the axial thread deposit target position Ztarget.

2. Method according to claim 1, wherein the winding angle φspool describes the coordinate (3) of the thread (2) in the circumferential direction (4) on the spool (2) starting from a winding start (6) of the thread (1) on the spool (2) and continuing over all windings (7) of the spool (2).

3. Method according to claim 1 or 2, wherein a deposition of the thread (1) at the target position Ztarget is defined by an alternating thread guide target angle φalternating,target, which describes an adjustment angle of the alternating thread guide (5), which causes a thread deposition at the axial thread deposition target position Ztarget.

4. Method according to one of the preceding claims, wherein a rotary sensor (8) is used to determine the winding angle φspool in step a), which indicates the number of complete revolutions and / or partial revolutions of the coil (2).

5. Method according to one of the preceding claims, wherein the angular velocity Ωspool of the spool (2) during winding is adjusted during the winding of the spool (2) as a function of the increasing thickness of the spool Dspool; in such a way that a constant thread speed is achieved in upstream processing steps of the thread (1).

6. Method according to one of the preceding claims, wherein, during winding of the coil (2), a plurality of K values are used which are determined according to a predetermined scheme as a function of at least one of the following parameters: - winding angle φspool; - angular velocity Ωspool; - rotational speed of the coil nspool or frequency of the coil fspool; or - thickness of the coil Dspool.

7. Method according to one of the preceding claims, wherein in step d) the alternating thread guide (5) is controlled by a regulator (9) and wherein a present thread deposit position Zis and / or a present alternating thread guide angle φalternating,is is monitored and the regulator difference ΔZ = Ztar-get - Zis and / or Δφalternating = φalternaltng,target - φalternating,is is calculated as the input variable for the regulator (9).

8. Control device (10) for controlling a shuttle thread guide (5) of a device (11) for winding spools, designed to carry out a method according to one of claims 1 to 7, comprising at least a first control module (12) for calculating the alternating thread guide control angle φalternating,guide based on a detected winding angle φspool, and a second control module (13) for calculating an axial thread deposit target position Ztarget using the alternating thread guide control angle φalternating,control.

9. Control device (10) according to claim 8, additionally comprising a regulator (9) which is designed to receive a current thread deposit target position Ztarget and a thread deposit is position Zis and, based on the current thread deposit target position Ztarget and the thread deposit is position Zis, to generate an output signal (14) for the regulated control of the thread deposit.

10. Control device (10) according to claim 8 or 9, comprising a common timer which is used to detect the winding angle φspool and Zis, wherein no further timer exists to control the alternating thread guide (5).

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