EP0986511A1

EP0986511A1 - Method for winding up a thread

Info

Publication number: EP0986511A1
Application number: EP99916861A
Authority: EP
Inventors: Klaus Bartkowiak
Original assignee: Barmag AG; Barmag Barmer Maschinenfabrik AG
Current assignee: Oerlikon Barmag AG
Priority date: 1998-03-20
Filing date: 1999-03-22
Publication date: 2000-03-22
Also published as: CN1258259A; WO1999048786A1; CN1197752C; US6308907B1; TW496849B

Abstract

The invention relates to a method for winding up a continuously fed thread on a spool (5) which is formed on a tube (6). To this end, the thread is guided back and forth within a traversing travel (H) by means of a thread guide (11), and is placed with a winding angle on the spool (5). The traversing thread guide (11) is slowed each time within a reverse distance section (B) by a finite deceleration of a guiding speed so that it can reverse at the ends of the traversing stroke, and is accelerated up to the guiding speed again by a finite acceleration. The acceleration and deceleration of the traversing thread guide are controlled in such a way that the length of the reversing distance section expands as the diameter of the spool increases.

Description

- 1 -

Ner driving to wind a thread

The invention relates to a method for winding a continuously running thread into a bobbin according to the preamble of claim 1 and a device for carrying out the method according to the preamble of claim 13

When winding the thread into a bobbin, a stable bobbin build-up, a packing density that is as constant as possible as well as good running properties during subsequent processing are always sought. The end faces of such bobbins can lie in an normal plane, so that cylindrical bobbins result, or relative to this normal plane be inclined so that a biconical bobbin is formed When winding the bobbins, the problem arises that due to the thread reversal, a mass accumulation occurs at the bobbin edges, which leads to hard bobbin edges or to a bead-like bobbin edge

From EP 0 453 622 a method and a device are known in which the traversing thread guide executes a relatively high deceleration and acceleration in the reversing area.This results in an undefined thread placement in the reversing area. If the retardation and accelerations are too high, slipping thread layers occur at the bobbin edge area, leading to a Driving undefined bobbin edge construction If, on the other hand, the deceleration and acceleration of the traversing thread guide are carried out too slowly, a relatively large mass accumulation occurs at the bobbin edges

Accordingly, it is an object of the invention to provide a method and an apparatus for winding a thread into a bobbin, in which a thread is deposited in the edge area with minimal mass accumulation - 2 -

According to the invention, this object is achieved by a method having the features of claim 1 and by a device having the features of claim 13. Further advantageous developments of the invention are defined in the subclaims

When traversing, the thread is deposited according to a speed function of the traversing thread guide.This speed function is characterized by three sections.First, the thread guide must be accelerated from the reversal point to a guiding speed.The distance that the thread guide travels until he has reached the desired guiding speed is defined as the reversing distance The thread guide is then moved at the guide speed to the opposite end of the traversing stroke. The distance covered is referred to here as the linear path. At the opposite end, the thread guide is decelerated out of the guide speed in such a way that it has zero speed at the opposite reversal point. The speed passed during the delay phase Distance is also defined as a reversal distance. The two reversal points thus result in the defined length of the traversing stroke by adding these Three sections The reversal distance of the thread guide is essentially determined by the set acceleration or deceleration of the thread guide.The method according to the invention now uses exactly the acceleration or deceleration of the thread guide to influence the thread deposit.This is done by controlling the acceleration and deceleration in such a way that the lengths of the Continuously lengthening reversal distances with increasing spool diameter of the bobbin This ensures that the mass accumulation becomes smaller with increasing spool diameter in the edge area and thus no bulge-like bobbin edges occur The shorter the reversal distance, the lower the mass accumulation. However, the thread placement within the reversal distance remains stable, since on the circumference a - 3 -

nes cylinder with a larger diameter, a thread reversal with a larger radius is necessary

In a particularly advantageous development of the invention, a minimum length of the reversal path is set for each spool diameter, in which a fixed thread position on the spool surface is ensured. This allows the mass accumulation in the reversal paths to be minimized during the entire winding travel. This method variant is based on the knowledge that the thread can be deposited on the bobbin surface within the reversing distance with a minimum radius without the thread slipping on the bobbin surface

Since the minimum length of the reversal path essentially depends on the minimum radius of curvature of the thread layer and the respective crossing angle, the method variant from claim 3 is particularly advantageous in order to continuously determine the minimum length of the reversal path.Here, the minimum radius of curvature is the quotient between the bobbin diameter and the Double the coefficient of friction of the bobbin surface can be calculated The coefficient of friction of the bobbin surface for textile threads is in the range of 0.2 to 0.6.For example, with a bobbin diameter of 200 mm, a minimum radius of curvature of the thread deposit within the reversing distance of 167 to 500 mm was obtained

In order to achieve a high degree of flexibility when winding the thread, the minimum length of the reversing path is continuously calculated by means of a control device and converted into control signals for controlling the acceleration and deceleration of the traversing thread guide

It is particularly advantageous here if the coil diameter is continuously recorded and the control unit is specified for calculating the minimum length of the reversal distance. Since the coefficient of friction of the coil surface is essentially from - 4 -

Depending on the type of thread and the traversing program, this can be stored as a value in the control unit. The wound crossing angle of the thread is also known by the traversing program and is stored in the control unit. The control unit, which is formed, for example, by a microprocessor, continuously calculates the minimum length of the Reversal distance off The calculated value is then immediately converted into control signals in order to control a drive of the traversing thread guide accordingly

The method according to the invention can be used both for winding the thread in a wild winding with a constant crossing angle or in a precision winding with changed crossing angles

In a further advantageous modification, the guiding speed of the traversing thread guide can be changed.This means that a different thread deposit can be generated in each single stroke within a double stroke.An advantageous linkage can also be achieved with a mirror interfering method.As a mirror, the appearance of the bobbin is referred to, in which the winding turns in successive layers Laying pieces of thread in the same direction more or less exactly on top of each other The symptoms of such mirrors are usually avoided by constantly moving the guiding speed or the traversing speed, which is specified as the number of back and forth movements (double stroke) of the traversing thread guide per unit of time, between an upper and lower limit is reduced and enlarged. By combining the changes in the reversal distances and a mirror disturbance, an even better binding of the thread layers in the edge region d he reached the coil

In a further preferred embodiment variant according to claim 10

The length of the traversing stroke can be changed. This allows the build-up of high to be achieved even with settings with slow accelerations and decelerations

Avoid edges Here, every form of breathing in combination with the change of the reverse distance possible. Another advantage is that the change in thread tension caused by breathing can be substantially compensated for. When winding a bobbin, it is particularly important that a uniform tensile force is applied over the length of the thread and over the length of the bobbin. This also improves the running properties of the spool.

The method variant according to claim 11 is particularly suitable for influencing the coil structure within the linear path of the traversing stroke. However, increasing the guide speed in the linear range without changing the deceleration would automatically lead to an extension of the reversal distance. This also gives you the option of changing the length of the reversing section solely by controlling the guiding speed.

The method and the further advantageous method variants and a device for carrying out the method are described with the aid of the attached drawings below.

They represent:

1 shows a thread deposit on a bobbin during a traversing stroke;

2 shows a thread deposit on the bobbin surface in the reversal area;

3 shows an exemplary embodiment of a device for carrying out the method according to the invention.

1 shows a thread deposit on a bobbin during a traverse stroke. A coil 5 is shown in the upper half of the picture. The coil 5 is wound on a sleeve 6. For this purpose, the sleeve 6 is placed on a winding spindle 7. It is a cylindrical coil 5 wound with a constant crossing angle α with the end faces 1. However, the coil 5 could also be a - 6 -

have biconical shape or any shape. The bobbin 5 could be wound on any type of winding, such as wild winding, precision winding or step-precision winding as well as their combinations. In order to deposit a thread on the bobbin, the bobbin 5 is by means of one not shown here Friction roller or driven directly by the winding spindle 7 The incoming thread is then guided shortly before being placed on the bobbin by a traversing thread guide 11 in the direction of movement 8 from the left end of the bobbin to the right end of the bobbin and in the direction of movement 9 from the right end of the bobbin to the left end of the bobbin of the traversing thread guide 11

The traversing thread guide could be driven, for example, by a linear drive or a belt drive. Here, the linear drive or the belt drive is connected, for example, to a stepper motor. The movement of the thread guide could then be precisely controlled via a programmable control unit. In the lower half of FIG. 1 there is a thread layer 2 Shown on the bobbin surface 10, which is deposited during a traversing stroke. The traversing stroke H, which is equal to the wound length of the bobbin, is limited by the reversal point 3 located at each end. The reversal point 3 is the position in which the thread guide does not If the speed now begins with the traverse stroke on the left side of the bobbin shown in FIG. 1, the thread is first laid within a reversing distance B _L with a steadily increasing crossing angle as soon as the thread guide is accelerated to a guiding speed which is necessary for laying the thread The thread is deposited on the bobbin surface with a constant crossing angle α. This distance is referred to herein as linear path L. At the right end of the bobbin, the traversing thread guide 11 is decelerated in such a way that it again has the speed 0 at the reversal point 3 B _R the thread is laid with a steadily decreasing crossing angle α. It is thus clear that the bobbin edges formed on the traversing stroke ends essentially depend on the thread deposit within the reverse path B depend The reversal distances B are determined exclusively by the acceleration and deceleration of the traversing thread guide. Thus, the thread position within the reversing path is directly related to the deceleration and acceleration of the traversing thread guide. The thread positions in the reversing paths are defined by a radius of curvature p

For this purpose, a thread layer 2 is shown in FIG. 2 on the bobbin surface 10 at the right reversal area of a bobbin. The abscissa of a diagram is placed by the reversal point 3. The abscissa represents the length of the traversing stroke H shows the circumferential direction of the spool The circumferential path u * t is entered on this. Here u is the circumferential speed and t is the time. The reversal point 3 denotes the end of the respective traversing stroke and is denoted by Ho in FIG. 2. Ho The thread position 2 within the reversal path B is defined by the radius of curvature p Between the ordinate and the thread position 2 the crossing angle α is entered. The traversing thread guide is thus guided with the guiding speed until the beginning of the reversing path. In point 4 1 the traversing thread guide begins to decelerate to to reversal point 3 From reversal point 3 to P point 4 2 the traversing thread guide is accelerated

A relationship between the radius of curvature p of the thread layer, the crossing angle α and the reverse path B can be derived from the arrangement shown in FIG. The reversal distance B can be derived from the equation

Calculate B = * p (1-cosα)

The smallest depositable radius of curvature of the thread layer, which does not cause the thread layer to slip, can be deduced from the relationship - 8th -

p _min = D / (2 * μ)

to calculate.

D is the coil diameter and μ is the coefficient of friction of the coil surface. Thus, with a uniform bobbin surface with increasing bobbin diameter, a thread layer with an ever increasing radius of curvature can be deposited without the thread layer sliding on the surface of the bobbin. In the case of textile yarns and the usual traversing programs, the coefficients of friction are in the range from 0.2 to 0.6. The minimum length of the reversal distance can thus be derived from the equation

B _min = D * (l-cosα) / 2μ

to calculate. This calculation can be carried out continuously, for example, by the control unit of a stepping motor which drives the traversing thread guide. The control unit generates control signals from the determined minimum length of the reversing path in order to control the stepper motor. The traversing thread guide is thus impressed with a deceleration and an acceleration which lead to a minimum radius of curvature and thus to a minimum length of the reverse path. The thread length stored per unit of time is thus reduced to a minimum.

The method according to the invention thus enables a thread to be wound into a bobbin with a more uniform mass distribution on the bobbin surface, regardless of breathing. In order to obtain a further equalization of the packing density of the coil structure, breathing, ie a change in the traversing stroke, can also be carried out. It is also possible to change the guide speed according to an arbitrary time program in order to generate a mirror disturbance, ie to avoid image windings. 3 shows an exemplary embodiment of a device for using the method according to the invention. Here, the traversing thread guide 11 is moved back and forth within a traversing stroke H by means of a belt drive 30. The belt drive 30 is formed by the pulleys 26, 27 and 24. The traversing thread guide 11 is attached to a belt 12 which wraps around the pulleys 26, 27 and 24 and is thereby moved back and forth between the pulleys 26 and 26. The pulley 26 is rotatably mounted on an axle 29, the pulley 27 is rotatably mounted on the axle 28 The pulley 24 is connected to a drive shaft 25 which is driven in both directions by means of an electric motor 23, for example a stepping motor. The electric motor 23 is controlled by a control device 19. The control device 19 is connected to a control unit 13

Parallel to the belt tensioned between the pulley 26 and 27, a winding spindle 7 is arranged below the belt drive, on which the sleeve 6 is fastened. On the sleeve 6, the coil 5 is wound. The speed of the winding spindle 7 is detected by means of a speed sensor 22 and the control unit 13 is given up. The ratio between the traversing speed and the peripheral speed of the coil can be set. Since the winding spindle 7 belongs to a winding device which drives the coil 5 at a constant peripheral speed, the respective wound diameter of the coil can be calculated from the rotational speed. This calculation is carried out within the control unit 13. The control unit 13 has a data input and a data memory in order to record the friction values of the coil surface and the crossing angle of the coil winding. On the basis of the stored data and the continuously measured speed, the control unit 13 can continuously calculate the minimum length of the reversal paths at the traversing stroke ends The control unit converts values into control signals and supplies them to the control device 19. The control device 19 controls the electric motor 23 accordingly, so that the traversing thread guide 11 with an acceleration or - 10 -

Delay is applied, which ensures compliance with the minimum length of the return path.

11 -

Reference list

1 face

2 thread layer

3 reversal point

4 transition point

5 coil

6 sleeve

7 winding spindle

8 Direction of movement

9 Direction of movement

10 coil surface

11 traversing thread guide

12 straps

13 control unit

18 threads

19 control unit

22 speed sensor

23 electric motor

24 pulley

25 drive shaft

26 pulley

27 pulley

28 axis

29 axis 30 belt drive

Claims

- 12 patent claims

1. A method for winding a continuously tapering thread to form a bobbin, in which the thread is moved back and forth within a traversing stroke by means of a traversing thread guide and is deposited on the spool with a crossing angle, the traversing thread guide being reversed at the ends of the The traversing stroke is braked from a guide speed by a finite deceleration and is accelerated back to the guiding speed by a finite acceleration, characterized in that the acceleration and deceleration of the thread guide is controlled such that the length of the reverse path (B ) extended with increasing coil diameter (D) of the coil.

2. The method according to claim 1, characterized in that a minimum length of the reverse path (Bmi _n ) is set for each bobbin diameter, in which a fixed thread position on the bobbin surface is guaranteed.

3. The method according to claim 2, characterized in that the minimum length of the reverse path (B _m i _n ) by a radius of curvature of the thread layer

(P _m i _n) is determined in the reversal region and the respective crossing angle (α), wherein the radius of curvature at the respective coil diameter (D) must be maintained at least to prevent slippage of the yarn layer occurs on the package surface.

A method according to claim 3, characterized in that the minimum radius of curvature (pmin) can be calculated by the quotient between the coil diameter (D) and twice a coefficient of friction (μ) of the coil surface. - 13 -

Method according to Claim 3 or 4, characterized in that the minimum length of the _{reversal distance} (B _mm ) can be calculated using the equation B _mιn = p _mm (1-cosα), where p _{mιn denotes} the minimum radius of curvature and α the crossing angle

Method according to one of the preceding claims, characterized in that a control unit continuously determines a minimum length of the reversing path for each bobbin diameter during the winding travel and generates control signals from this for controlling the acceleration and deceleration of the traversing thread guide

A method according to claim 6, characterized in that the coil diameter is continuously recorded and the control unit is given, that the coefficient of friction of the coil surface is stored in the control unit and that the crossing angle is determined by a traversing program executed by the control unit

Method according to one of the preceding claims, characterized in that the winding takes place with changing crossing angles of the thread layer and that the minimum length of the reversing path is determined each time the crossing angle changes, regardless of the bobbin diameter

Method according to one of the preceding claims, characterized in that the guiding speed of the traversing thread guide to

The purpose of a mirror disturbance is changeable

Method according to one of the preceding claims, characterized in that the length of the traversing stroke can be changed for the purpose of breathing - 14 -

Method according to one of the preceding claims, characterized in that the guide speed before the reversal of movement of the thread guide is smaller or greater than the guide speed after the reversal of movement of the thread guide

Method according to one of the preceding claims, characterized in that the guiding speed of the traversing thread guide can be controlled within the traversing stroke

Device for winding a continuously running thread (18) into a bobbin (5) formed on a sleeve (6), in particular for carrying out the method according to one of Claims 11, with a winding device for driving the bobbin (5) with an essentially constant catch speed and with a traversing device for guiding the thread (18) back and forth within a traversing stroke, the thread (18) being moved transversely to its running direction by a traversing thread guide (11), the traversing thread guide (11) being driven by a drive (23, 30) is driven and the speed and acceleration of the drive (23, 30) can be controlled by a control device (19), characterized in that the control device (19) is connected to a control unit (13), which control unit (13 ) during the winding travel continuously determines a minimum length of the reversal distance for each bobbin diameter and from this control signals for controlling the loading leunung and the delay of the traversing thread guide (11) generated

Apparatus according to claim 12, characterized in that the control unit (13) is connected to a speed sensor (22) which detects the speed of the coil (5), and that the control unit (13) has a data input and a data memory for recording the coefficients of friction of the Has coil surface and crossing angles of the coil winding