JP2002128390A - Filament winder and filament winding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of yarn breakage or the like caused by the bite of filament by preventing the overlap of yarn in the same direction in the innermost layer region of a yarn package. SOLUTION: This filament winder is provided with a bobbin holder for holding a bobbin, a traverse device and a control device for controlling the driving thereof. During the time from the start of winding filament until the diameter increase quantity of a package reaches a specified quantity set in a range of 0-5 mm, the traverse speed of the traverse device is controlled to continuously and/or abruptly increase or decrease the twill angle of filament by a specified angle set in a range of 0-10 deg.. Since wind angle control is performed on the basis of the package diameter, it is easy to control the package diameter to an appropriate value when shifting from a wind angle abrupt changing process to a normal winding process. The package diameter is computed using the rotating speed of the bobbin holder obtained from a theoretical expression. The wind angle control is thereby performed appropriately even during winding, using a stepped contact roller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a yarn winding machine such as a yarn winding machine for forming a package by winding a yarn such as a multifilament yarn of synthetic fiber on a bobbin, and a yarn winding machine. An object of the present invention is to improve the unwinding property of a yarn in a package by preventing the yarn from being entangled or entangled in the innermost layer of the package.

[0002]

2. Description of the Related Art In general, a process of forming a yarn package by a yarn winding machine is performed by winding a yarn around a bobbin while giving an appropriate twill angle using a traverse device. Usually, the rotation speed of the bobbin holder holding the bobbin is feedback-controlled so that the winding speed of the yarn is constant. That is, the rotational speed of the bobbin holder is reduced as the package diameter increases as the winding process proceeds, so that the surface speed of the package is kept constant. At this time, in order to prevent the occurrence of ribbon winding, the traverse speed is also reduced in accordance with the deceleration of the bobbin holder, and a constant winding ratio winding that maintains a constant ratio (wind ratio) between the traverse speed and the rotation speed of the bobbin holder is employed. In some cases, winding of the yarn is performed.

[0003]

A package formed by winding a thread on a bobbin is subjected to internal stress, and the size of the package tends to increase as the inner layer. For this reason,
Immediately after the start of winding of the yarn, if winding is performed with almost no change in the twill angle, the number of overlapping yarns in the same direction increases in the innermost layer region of the package. In this case, the yarns on the outer layer side in the innermost layer region are bitten or entangled between the yarns on the inner layer side. As a result, when the yarn is unwound in a subsequent step, the unwound property is deteriorated because the inner yarn is adhered, and the yarn may be broken in some cases. Further, if the winding angle at the start of winding is increased, there is also a problem that yarn slippage is likely to occur, or the yarn tension becomes too high, leading to breakage of a single yarn.

Therefore, conventionally, for example, Japanese Patent Laid-Open No. 10-1720
No. 8, etc., winding is started with a small twill angle, and the winding angle is gradually increased over a certain period of time (about 30 to 60 seconds) so that the twill angle becomes a predetermined size required for a normal winding process. Once reached, it has been proposed to switch to a constant winding ratio winding. However, the above-mentioned conventional method does not exhibit a sufficient effect for improving the unwinding property of the package.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a yarn winding machine and a yarn winding method capable of improving the unwinding property of a yarn package. The features of the yarn winding machine according to the present invention include a bobbin holder that holds and rotates a bobbin that winds a yarn, a traverse device that traverses the yarn left and right, a rotation drive of the bobbin holder, and the traverse. And a control device for controlling the driving of the device, comprising: starting winding of the yarn, and until the amount of increase in the diameter of the package formed on the bobbin reaches a predetermined amount. During the initial winding, a traverse speed of the traverse device is controlled by the control device, and a traverse angle sudden change step of continuously and / or rapidly changing the traverse angle by a predetermined angle can be executed. The present invention is configured to be able to change a set value of a control factor related to a helix angle and a set value of a control factor related to a package diameter which are set at the time of executing the sudden angle changing step. In the above description, the control factors relating to the traverse angle are the initial traverse angle, the final traverse angle, the increase amount of the traverse angle, and the like, and the control factors relating to the package diameter are the final diameter dimension, the diameter increase amount, and the like. The yarn winding machine according to the present invention configured as described above includes a twill angle sudden change step of changing the twill angle continuously and / or rapidly in a relatively short time until the package diameter reaches a predetermined size. Since it can be executed, the directionality of the yarn can be different between the inner layer and the outer layer in the innermost layer region, thereby preventing the yarn from biting and entanglement in the innermost layer region of the package and contributing to the improvement of the unwinding property I do. Also, since the set values of the control factor of the twill angle and the control factor of the package diameter set in the twill angle sudden change process can be changed, it is easy to change the yarn winding conditions such as the type of yarn and the package shape. It is possible to respond. The change of the twill angle in the twill angle sudden change step may be in a direction of increasing or decreasing.

In the yarn winding machine, the controller calculates the package diameter formed on the bobbin from the rotation speed of the bobbin holder during the steep angle changing step, and adjusts the traverse speed according to the change in the package diameter. It may be set to control the traverse device to change. Alternatively, the control device may be set so as to control the traverse speed of the traverse device based on the rotation speed of the bobbin holder calculated from the theoretical formula during the step of suddenly changing the twill angle. The control device calculates the theoretical formula based on an error between the bobbin holder rotational speed specified by the feedback control after the transition from the steep angle changing process to the normal winding process and the bobbin holder rotational speed obtained from the theoretical formula. It is desirable to have a means for correcting.

On the other hand, a feature of the yarn winding method according to the present invention is a method for winding a yarn around a bobbin held on a bobbin holder while traversing the yarn left and right by a traverse device. From the start, the increase in the diameter of the package formed on the bobbin is 0 to 5 mm
During the initial winding up to the predetermined amount set in the range, the traverse speed of the traverse device is controlled so that the traverse angle is continuously and only by the predetermined angle set in the range of 0 to 10 °. And / or performing a steep angle changing step for abruptly changing the angle. By adopting such a yarn winding method, a steep angle change step is performed at the initial stage of winding the yarn, and the directionality of the yarn can be made different between the inner layer and the outer layer in the innermost layer region of the package. Biting and entanglement of the yarn are prevented, and the unwinding property is improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of a yarn winding machine M to which the present invention is applied, a yarn S (for example, a synthetic fiber multifilament) continuously spun from a spinning device (not shown). 1 schematically illustrates a configuration of a spinning winder that winds a filament yarn or the like. The yarn winding machine M includes two bobbin holders BH, BH on which a plurality of bobbins B are mounted, and a contact roller that contacts a yarn package P formed on the bobbin B of the bobbin holder BH at the winding position. CR. The two bobbin holders BH, BH are individually provided with drive motors mb, mb, respectively, and are attached to the frame f so that the positions can be freely switched alternately between the winding position and the standby position. Contact roller C
R is attached to a slide box sb that can be moved up and down on the frame f so that the slide box sb can be moved up and down to adjust the distance between the bobbin holder BH and the contact roller CR. The lifting and lowering of the slide box sb is guided by a slide shaft g erected on the frame f, and the contact pressure of the contact roller CR with the thread package P is controlled by a support force control means a constituted by, for example, an air cylinder mechanism. A traverse device t for traversing the yarn S in the axial direction of the bobbin B is provided beside the slide box sb. The traverse device t is provided with a drive motor mt. The drive motor mb of the bobbin holder BH and the drive motor mt of the traverse device t are controlled by the control device U.

The control unit U controls the drive of the bobbin holder BH and the traverse device t to cause the yarn winding machine M to execute a steep angle changing process and a normal winding process (multi-jump process) described later. There are provided means for calculating the package diameter formed on the bobbin from the number of rotations of the bobbin holder during the step of suddenly changing the twill angle, and means for correcting the theoretical formula for calculating the number of rotations of the bobbin holder. Further, setting means for setting values of various parameters such as a twill angle and a package diameter at the time of executing the yarn winding step is provided in the control device U.

Although not shown, the bobbin holder BH
A rotation speed sensor for detecting the rotation speed of the contact roller CR is provided at an appropriate position. If necessary, a drive motor for rotating the contact roller CR may be provided.

The yarn winding machine M converts the yarn S into a bobbin B.
In the present invention, in performing the winding step of winding the package P to form a package P, in the initial stage of winding from the start of winding until the diameter of the package increases by a predetermined amount (for example, 0 to 5 mm). Set the angle from the initial set value to 0, for example.
A steep angle changing step of continuously and / or abruptly changing by 10 ° to 10 ° is performed. The control of the helix angle is performed by changing the traverse speed of the traverse device t. The change of the twill angle may be increased or decreased from the initially set twill angle. The amount of change in the twill angle is
It is considered preferable to make the ratio proportional to the amount of increase in the package diameter, but it is not impeded that control is performed according to other functional relationships according to conditions. In any case, by changing the twill angle continuously and / or rapidly in a relatively short time at the beginning of winding,
It is possible to prevent the yarns from overlapping in the same direction in the innermost layer region of the package, to prevent the yarns from biting or tangling, and as a result, to improve the unwinding property of the package.

[Embodiment 1] The control of the twill angle in the above-described step of suddenly changing the twill angle is performed by a control device provided in the yarn winding machine M
For example, it is performed as follows. At the start of the winding step, the control factors related to the twill angle and the control factors related to the package diameter are set in advance based on the yarn winding conditions. The control factors relating to the twill angle include an initial twill angle A ₀ (for example, 4 to 6 °) at the start of winding, a final twill angle An (for example, 6 to 14 °) at the end of the sudden change in the twill angle, and, if necessary, The hoop angle increase amount Ap (for example, 0 to 10 °) is set as the target. It is desirable that the value of the final twill angle An be set to a value equal to or as close as possible to the twill angle in performing a normal winding step. On the other hand, the control factor related to the package diameter is the package diameter increase amount D during the twill angle sudden change process.
p (for example, 0 to 5 mm) or the target package diameter Dn at the end of the step of suddenly changing the twill angle. When the package diameter at the start of winding, that is, the bobbin diameter is D ₀ ,
A value obtained by adding the increase amount Dp in the bobbin diameter D ₀ becomes the target package diameter Dn at the end of the winding angle abrupt change process.

Assuming that the package diameter at an arbitrary point in the traverse angle sudden change step is Dk, the traverse angle Ak at that time is the value of Dk having the previously set values of A ₀ , An, D ₀ and Dn as constants. Given as a function. That is, the formula: A
k = F (Dk). In the above example, as the control factors to be set in the step of suddenly changing the traverse angle, the initial traverse angle A ₀ ,
The target package diameter Dn is selected. Instead of this, the initial hoop angle A ₀ , the hoop angle increment Ap, and the target package diameter Dn are set, or the initial hoop angle A ₀ , the hoop angle increment Ap,
An example in which the package diameter increase amount Dp is set can also be adopted.

By the way, the yarn speed Ys is kept constant even during the step of suddenly changing the twill angle. The traverse speed Tk when the helix angle is Ak is the tangent tan (Ak) of the helix angle Ak.
And the rotational speed of the bobbin holder Bk
Is inversely proportional to the package diameter Dk. Further, in general, the value of the tangent tan θ can be approximated to a proportional relationship with the angle θ when the angle θ is as small as about 10 degrees or less. From the above, the hoop angle Ak and the package diameter Dk
Can be replaced with a relational expression between the traverse speed Tk and the reciprocal of the rotational speed Bk of the bobbin holder. Formula: Tk = F (1 / Bk) Accordingly, in the yarn winding machine M of the present embodiment, the control device U measures the rotation speed Bk of the bobbin holder with a rotation speed sensor or the like, and based on the value, traverses the required traverse. By calculating the speed Tk, the traversing angle Ak in the traversing angle suddenly changing step can be controlled.

When winding the yarn on the surface of the bobbin B mounted on the bobbin holder BH to form the package P, the contact roller CR is usually brought into contact with the surface of the package P with a predetermined contact pressure as shown in FIG. Then, the rotation speed of the bobbin holder BH is feedback-controlled so that the rotation speed of the contact roller CR becomes a constant speed corresponding to the yarn production speed. Since the diameter of the package P increases as the winding of the yarn proceeds, the contact roller CR
In order to keep the peripheral speed of the package P in contact with, that is, the winding speed of the yarn constant, a deceleration process for gradually reducing the rotation speed (angular speed) of the bobbin holder BH is performed. Such a deceleration process is executed by a feedback speed control such as a PI control based on a deviation from a target rotation speed by measuring the rotation speed of the contact roller CR by a rotation speed sensor. As described above, when the yarn winding is performed by the feedback control, the command rotation speed to the bobbin holder BH calculated by the feedback control or the bobbin holder B measured by the sensor is used to calculate the traverse speed Tk.
The actual rotation speed Bk of H can be used.

[Embodiment 2] The helix angle is determined by the traverse speed. The value of the rotation speed Bk of the bobbin holder, which is the basis for calculating the traverse speed Tk, is determined by a command rotation speed by feedback control or a value measured by a sensor. Not only can be used, but it can also be calculated from a theoretical formula. This is used, for example, when a large-diameter step is formed at both ends of the contact roller CR to protect the yarn of the package inner layer. If the contact roller CR is stepped, the package will roll up to a certain extent,
The rotation speed of the bobbin holder BH, which is feedback-controlled for a certain period of time until the surface of the bobbin holder BH contacts the surface of the small diameter portion of the stepped roller, is controlled to a constant speed because the step of the contact roller CR is always in contact. . For this reason, the command rotation speed by the feedback control or the rotation speed of the bobbin holder BH actually measured by the sensor becomes a constant value. If the traverse speed is set based on these rotation speeds, the winding angle Ak does not change at the beginning of winding. Will be. As a result, the yarns are overlapped and wound in the same direction,
Causing biting or entanglement between the yarns of the inner and outer layers,
In some cases, the ribbon may be wound.

In such a case, the theoretical value of the rotational speed Bk of the bobbin holder is calculated based on a theoretical formula that is a function of the elapsed time t from the start of winding, regardless of the actual rotational speed of the bobbin holder BH. Based on the theoretical value, the traverse speed in the steep angle changing step is controlled. The theoretical formula used in this example is, for example, the following formula (X).

[0018]

(Equation 1)

The meaning of each symbol in the above formula (X) is as follows. Bk: rotation speed from the winding start after t time the bobbin holder (rpm) B _0: winding rotation initial velocity of the bobbin holder at the time of the beginning (rp
m) Q: Yarn discharge amount (g / min) t: Elapsed time from the start of winding (min) W: Traverse width (mm) ρ: Winding density (g / cm ³ ) R ₀ : Bobbin radius (mm) π: Pi The initial value of the winding density ρ is appropriately set according to the type of yarn such as polyester or nylon, or according to the set value of the twill angle.

The stepped contact roller CR
Is used, when the rotation speed of the bobbin holder BH is controlled based on the theoretical formula (X) regardless of the rotation speed of the contact roller CR, the rotation speed of the bobbin holder BH actually measured by a sensor is obtained. When,
The rotation speed derived from the theoretical equation is in principle equal. Therefore, in this case, either the measured value or the theoretical value may be used as the value of the rotation speed of the bobbin holder BH, which is the basis of the calculation of the traverse speed in the traverse angle suddenly changing step.

[Embodiment 3] In the step of suddenly changing the twill angle in the initial stage of winding of the yarn winding step, as described above, until the package diameter reaches the set increase amount, the twill angle is set abruptly and / or continuously by the set angle. A process for changing the target is performed. Thereafter, when the package diameter reaches a predetermined value, the process shifts to a normal winding process. The control of the twill angle in the normal winding step may be performed by employing a control method called multi-jump processing. The multi-jump process is a control method for repeatedly performing a process of instantaneously changing (jumping) the twill angle in order to suppress the occurrence of ribbon winding, and as shown in FIG. 2, every time the package diameter increases by a certain amount. By changing the wind ratio, the twill angle is changed discontinuously by a small value. In the normal winding step, control is performed so that the wind ratio is constant in a section where the package diameter increases to a certain amount. The wind ratio has a proportional relationship with the value of (rotation speed of bobbin holder / traverse speed), and the rotation speed of the bobbin holder is subjected to a predetermined deceleration process to keep the yarn speed constant as the package diameter increases. Is done. Accordingly, in the section where the wind ratio is controlled to be constant, the traverse speed is also decelerated, and as a result,
In the section where the wind ratio is constant, the twill angle continuously decreases. When the amount of increase in the package diameter reaches a certain value, the traverse speed is increased to instantaneously change to a different wind ratio, and the twill angle jumps to the next section. As described above, by controlling the traverse speed, it is possible to perform a multi-jump process of keeping the wind ratio constant or jumping to a different wind ratio.

When the rotation speed of the bobbin holder BH is controlled based on the theoretical formula (X) as in the second embodiment, the transition timing from the steep angle changing step to the normal winding step is, for example, as follows. Is set to A wind ratio is calculated based on the rotational speed (actually measured value or theoretical value) of the bobbin holder BH during the steep angle change process, and the calculated wind ratio is set to the wind ratio corresponding to the final tangle angle An at the end of the steep angle change process. Wind ratio that is closest and avoids ribbon winding
When the target wind ratio is reached, the process moves to the normal winding process. By the way, when the rotation speed of the bobbin holder BH is controlled in accordance with the theoretical formula (X), the target package diameter Dn to be reached at the end of the step of suddenly changing the traverse angle.
Is set using the bobbin holder rotation speed calculated from the theoretical formula (X). When the theoretical value and the actually measured value of the bobbin holder rotation speed coincide with each other, the straight line of the change in the helix angle is indicated by a solid line Z in FIG. 3, and the wind ratio reaches the target wind ratio and suddenly changes. When the process is completed, the traverse angle becomes the final traverse angle An and the package diameter becomes the target package diameter Dn, so that the transition to the normal winding process for performing the multi-jump process can be smoothly performed.

However, when an error occurs between the theoretical value and the actually measured value of the bobbin holder rotation speed (for example, when the parameter Q in the formula X: the yarn discharge amount or ρ: the winding density has an error), When the wind ratio reaches the target wind ratio, the actual package diameter differs from the target package diameter Dn derived from the theoretical formula. As shown by the two-dot chain line α in FIG. 3, when it reaches the target wind ratio smaller package diameter D ₁ than the Dn, by continuing the winding process to maintain the target wind ratio, the winding angle Since the package diameter can reach Dn without abrupt change in, the transition to the normal winding step for performing the multi-jump processing can be smoothly performed. However in FIG. As shown by the two-dot chain line beta, package diameter D ₂ upon reaching the target wind ratio is also greater than the Dn. Then, in this case, wind ratio corresponding to the D ₂ in the normal winding process of performing multi-jump process is sometimes different from the target wind ratio. In such a case, a change in the wind ratio is required when shifting from the sudden change in the twill angle to the normal winding step, causing a rapid change in the twill angle, and as a result, problems such as twill drop occur. There is a risk.

Therefore, in the present embodiment, when the rotation of the bobbin holder BH is feedback-controlled based on the detected rotation speed of the contact roller CR, immediately after the transition from the steep angle changing step to the normal winding step or after a lapse of a predetermined time, the theoretical The command rotational speed of the bobbin holder BH calculated from the formula (X) is compared with the command rotational speed of the bobbin holder BH by feedback control, and the theoretical formula (X) is corrected based on an error between the two. . Specifically, it can be dealt with by correcting ρ: winding density in equation (X). Due to such correction processing, in the subsequent yarn winding process, when shifting from the steep angle changing process to the normal winding process, an error occurs between the package diameter derived from the theoretical formula and the actual package diameter. Can be suppressed.

When the rotation of the bobbin holder BH is controlled by feedforward control based on the theoretical formula (X), the rotation of the bobbin holder BH is performed immediately after the transition from the steep angle change step to the normal winding step or after a certain time has elapsed. Switch the drive to feedback control. Then, even after switching to the feedback control, the calculation of the command rotation speed of the bobbin holder BH based on the theoretical expression (X) is continued, and after a predetermined time has elapsed, the bobbin holder command rotation speed calculated for the feedback control and the theoretical expression Is compared with the command rotational speed calculated based on the above, and the theoretical formula (X) is corrected using the error between the two. This makes it possible to correct the rotation speed of the bobbin holder to an appropriate value when performing the feedforward control based on the theoretical formula in the subsequent winding process in the subsequent yarn winding process. As a result, in the next yarn winding process, when the wind ratio reaches the target wind ratio and completes the twill angle suddenly changing process, the actual package diameter and the package diameter derived from the theoretical formula can be matched. Since it is possible, it is possible to avoid a sudden change in the twill angle when shifting to the normal winding step.

[0026]

According to the present invention, it is possible to prevent the yarns from overlapping in the same direction in the innermost layer region of the yarn package by executing the step of suddenly changing the winding angle at the beginning of winding. Accordingly, the unwinding property of the package is improved, and there is no possibility that the yarn breaks during unwinding.

In the present invention, the control of the traverse angle (traverse speed) is performed on the basis of the package diameter, so that the transition from the traverse angle sudden change step to the normal winding step can be performed smoothly. In particular, when the multi-jump process is employed in the normal winding process, the package diameter at the end of the sudden angle change process, that is, when the package wind ratio reaches the target wind ratio at which to start the multi-jump process, is initially determined. It is easy to match with the set target package diameter. Therefore, when shifting from the sudden change in the twill angle to the normal winding process, there is no possibility that the twill angle changes instantaneously,
It is possible to surely prevent a twill drop or the like. In addition, since the end time of the sudden angle change process is set based on the package diameter, even if the winding process of yarns having different thicknesses (denier values) is performed, the normal winding from the sudden angle change process with the same package diameter is performed. It can be transferred to the process.

If the control of the traverse speed in the step of suddenly changing the traverse angle is set to be performed based on the rotation speed of the bobbin holder calculated from the theoretical formula, for example, a stepped contact roller having both ends having large diameters It is possible to perform appropriate twill angle control even when the winding step is performed using.

Further, after the transition from the steep angle changing process to the normal winding process, the bobbin holder rotation speed (theoretical value) obtained from the theoretical formula and the bobbin holder rotation speed specified by the feedback control (the command rotation speed by the feedback control) Or, by correcting the above-mentioned theoretical formula based on the error obtained by comparing with the actually measured rotation speed, the error between the actual package diameter at the end of the abrupt angle change process and the package diameter obtained from the theoretical formula is obtained. Can be eliminated. Therefore, the transition to the normal winding process can be smoothly performed regardless of whether the feedback control of the bobbin holder is performed or the feedforward control is performed during the abrupt angle changing process.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of a yarn winding machine to which the present invention is applied, and showing a schematic configuration thereof.

FIG. 2 is a view for explaining a yarn winding step by the yarn winding machine according to the present invention, and is a view of a package diameter (vertical axis).
6 is a graph showing the relationship between the angle and the twill angle (horizontal axis).

FIG. 3 is a graph for explaining a yarn winding step by the yarn winding machine according to the present invention, and is an enlarged graph showing a transition state from a steep angle changing step to a normal winding step. .

[Explanation of symbols]

M: yarn winding machine B: bobbin BH: bobbin holder C
R: contact roller P: thread package S: thread U: control device a: supporting force control means f: frame g: slide shaft sb: slide box t: traverse device mb: motor for driving a bobbin holder mt: driving of a traverse device Motor

Continued on the front page (72) Inventor Hidenori Torii 136 Takeda-Mukoshiro-cho, Fushimi-ku, Kyoto Murata Machinery Co., Ltd. F-term (reference) 3F056 FA02

Claims (5)

[Claims] 1. A bobbin holder for holding and rotating a bobbin on which a yarn is wound, a traverse device for traversing the yarn left and right, and a control device for controlling the rotational drive of the bobbin holder and the drive of the traverse device. A yarn winding machine, wherein the control device is provided between the start of winding of the yarn and an initial winding period until the amount of increase in the diameter of the package formed on the bobbin reaches a predetermined amount. By controlling the traverse speed of the traversing device, a step of rapidly changing the twill angle by continuously and / or suddenly changing the twill angle by a predetermined angle can be executed. A yarn winding machine characterized in that a set value of a control factor relating to an angle and a set value of a control factor relating to a package diameter can be changed. 2. The traverse device according to claim 1, wherein the controller calculates a package diameter formed on the bobbin from the rotation speed of the bobbin holder during the step of changing the traverse angle, and changes the traverse speed according to the change in the package diameter. 2. The yarn winding machine according to claim 1, wherein the yarn winding machine is set to control the following. 3. The yarn according to claim 2, wherein the control device is set to control the traverse speed of the traverse device based on the number of revolutions of the bobbin holder calculated from a theoretical formula during the sudden change of the twill angle. Strip winder. 4. The control device according to claim 1, wherein the bobbin holder rotation speed specified by the feedback control after the transition from the steep angle change process to the normal winding process is different from the bobbin holder rotation speed obtained from a theoretical formula. 4. The yarn winding machine according to claim 1, further comprising means for correcting the theoretical formula. 5. A method for winding a yarn around a bobbin held on a bobbin holder while traversing the yarn left and right by a traverse device, wherein the diameter of a package formed on the bobbin is changed after the winding of the yarn is started. Dimension increase is 0-5m
During the initial winding process until a predetermined amount set in the range of m is reached, the traverse speed of the traverse device is controlled so that the traverse angle is continuously set by the predetermined angle set in the range of 0 to 10 °. And / or performing a step of suddenly changing the twill angle.