JPH08259111A - String switching method for turret type automatic switching and winding machine - Google Patents

Abstract

PURPOSE: To secure the switching succeeding ratio of string, and while to prevent the deterioration of quality at the time of switching the string from the string package during the winding to an accelerated vacant bobbin by decelerating the bobbin winding speed after the feedback control of the winding speed is temporarily stopped. CONSTITUTION: Winding speed of a string winding package P is detected by a contact roller 7, and a motor 4 is controlled by a winding speed control device 9 through a driving power source on the basis of the winding speed signal at the time of concluding the winding so as to accelerate the winding speed of a bobbin holder 2. At the time of switching the string from the string package P to a vacant bobbin 3', after the feedback control of the winding speed is temporarily stopped, winding speed of the bobbin 3, which newly starts to wind the string, is decelerated till the traverse of the string is started again. Thereafter, feedback control of the winding speed of the bobbin 3, which started to wind up the string, is started again.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention According to the present invention, two sets of bobbin holders are arranged on a turret, and a bobbin inserted into one bobbin holder is wound with a yarn.
The present invention relates to a yarn switching method for a turret type automatic switching winder in which a set of bobbin holders is turreted and the yarns are sequentially switched to an empty bobbin inserted in the other bobbin holder.

[0002]

2. Description of the Related Art In recent years, with the rapid winding of synthetic fibers, from the viewpoint of energy saving and resource saving, the yarns are automatically switched alternately on the bobbins mounted on the two bobbin holders for winding. A so-called "turret-type automatic switching winder" for performing continuous winding work without interruption has been proposed and put into practical use.

Further, in general, a contact roller (also referred to as "touch roller") is contact-rotated with the outer peripheral surface of the yarn package being wound, and the winding speed is always detected by the rotation speed of the contact roller, while the yarn is being wound. Spindle drive type automatic winders, in which the rotation of the bobbin holder for inserting the strip package is feedback controlled so as to maintain a preset winding speed, are also widely used.

When winding a medium denier or fine denier yarn having a small yarn tension by using such a turret type automatic switching winder of the spindle drive system, a large denier yarn having a large yarn tension is used. It is more difficult to switch the yarns compared to the case. For this reason, a method for stably and reliably switching the yarns is required. This problem is mainly caused by a sudden and sudden decrease in the winding tension when the yarns are switched. For this reason,
Before changing the yarn, it is possible to compensate for the decreasing tension by setting the decreasing winding tension high in advance so that the yarn breakage does not occur (that is, increasing the winding speed). (Japanese Patent Laid-Open No. 61-229778),
JP-A-5-15530 and JP-A-5-15531).

Certainly, according to this method, the winding tension can be set to a high level by increasing the winding speed of the yarn package being wound at the time of switching the yarn. In addition, the peripheral speed of the empty bobbin that tries to wind by switching the yarn on it can be increased in advance in advance.
It is possible to compensate for the decrease in the winding tension that occurs when the yarns are switched, and as a result, the yarn switching success rate increases.

However, in the method, attention is paid only to increasing the success rate of yarn switching, and at the beginning of winding after the completion of switching, the winding tension of the bobbin is high, which is caused by the high winding tension. No consideration was given to quality. That is, according to the conventional method, since the winding speed is gradually reduced to the steady winding speed even after the yarn switching is completed, the winding speed is reduced even though the yarn traverse is started. , There exists a state in which the coil is wound at a speed higher than the steady speed.

By the way, increasing the winding tension of the yarn results in slightly stretching the yarn being wound, which causes the innermost layer portion of the yarn package (at the beginning of winding, It causes deterioration of the quality of the yarn formed on the bobbin (fine denier, dyeing spots, etc.).

As an attempt to solve the deterioration of the quality of the innermost layer yarn that occurs at the beginning of winding into the yarn package, Japanese Patent Laid-Open No. 105331/1993 proposes the following method.

That is, the bobbin take-up speed, which has been increased more than the steady take-up speed at which the take-up is newly started and the take-up is newly started, is shortly taken until the start of the yarn traverse. In the meantime, it is intended to decelerate and return to the steady winding speed as quickly as possible.

However, the above-mentioned Japanese Patent Laid-Open No. 5-15
As described in Japanese Patent Application Laid-Open No. 530-53053 and Japanese Patent Application Laid-Open No. 5-15531, a contact roller driven by being pressed against the outer peripheral surface of a yarn package being wound (Japanese Patent Application Laid-Open No. 5-15531)
In Japanese Patent No. 15530 and Japanese Patent Laid-Open No. 5-15531, the term "touch roller" indicates a transient characteristic (hunting) associated with feedback control during a yarn switching period. For this reason, the bobbin take-up speed, which has been increased more than the steady take-up speed at which the take-up has been newly started and the new take-up has been completed, takes a short time before the start of the yarn traverse. , Even if an attempt is made to decelerate and return to the steady winding speed as quickly as possible, the transient speed (hunting) associated with the feedback control makes it possible to decelerate and return the winding speed to the steady winding speed as quickly as possible. Disappear. Therefore, the innermost layer yarn wound with a winding tension higher than the winding tension of the yarn capable of guaranteeing good quality inevitably exists in the yarn package.

[0011]

DISCLOSURE OF THE INVENTION As a result of intensive studies on such problems, the present inventors have found that in order to maintain a good success rate at the time of yarn switching, winding at the time of yarn switching is performed. A spindle drive type turret that can automatically and reliably switch the yarn tension while maintaining the tension in an appropriate range and without affecting the quality of the innermost layer of the yarn. An object of the present invention is to provide a yarn switching method in a type automatic switching winder.

[0012]

According to the present invention, two sets of bobbin holders each having a bobbin inserted therein are arranged in a turret, and a yarn package having a predetermined winding amount is formed on one bobbin. Then, in the yarn switching method of the turret type automatic switching winder that rotates the turret to automatically switch the yarn to the other empty bobbin, the yarn is pressed against the outer peripheral surface of the yarn package being wound. A drive device for a bobbin holder which is provided with a contact roller for detecting the winding speed of the yarn package by being frictionally driven, and the winding speed signal detected by the contact roller at the completion of winding is being wound. By feeding back to the bobbin holder to increase the winding speed from the steady winding speed to a preset winding speed, and advance the running speed from the yarn package being wound to the steady winding speed or more in advance. When the turret is rotated to the empty bobbin and the yarn is switched, the winding speed to the bobbin holder in which the yarn package being wound is inserted according to the winding speed signal detected by the contact roller. Feedback control of the bobbin is temporarily stopped, and after the yarn is switched, the winding speed of the bobbin is taken up until the traverse of the yarn is restarted for the bobbin in which the winding of the yarn is newly started. Is gradually decelerated stepwise or continuously to return to a substantially constant winding speed, and then the winding detected by the contact roller is wound on the bobbin where the winding of the yarn is started. Depending on the speed signal
There is provided a yarn switching method for a turret type automatic switching winder, characterized in that feedback control of a winding speed to a bobbin holder into which a yarn package being wound is inserted is restarted.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic explanatory view illustrating a turret type automatic switching winder according to the spindle drive method of the present invention.

In FIG. 1, (1) is a turret, and the turret (1) is a turret table (1
a), a rotary shaft (1b) fixed to the central position of the turret table (1a), and a drive motor (1c) for rotationally driving these members. The drive motor (1c) is fixed to a winder frame (not shown), and the rotary shaft (1b) is rotatably supported by the winder frame (not shown). There is.

On the turret table (1a),
The bobbin holders (2) and (2 ') into which the bobbins (3) and (3') are inserted are rotatably supported, and the bobbin holders (2) and (2 ') are respectively driven by the drive motor (4). ) And (4 ').

Further, in FIG. 1, reference numerals (5) and (5 ') are frequency variable power sources called inverters, which are provided exclusively for the drive motors (4) and (4'), respectively. ing. Therefore, frequency power supply (5)
By (5 ') and (5'), the rotational speeds of the drive motors (4) and (4 ') are independently controlled.

However, when the yarns are switched, the drive motors (4) and (4 ') rotate about the rotary shaft (1b) of the turret table (1a) as a central shaft, so that power is supplied. The contacts also rotate with this. In order to cope with this situation, the rotating shaft (1b) is provided so that the frequency power supplies (5) and (5 ') can be continuously supplied to the drive motors (4) and (4') without interruption. Slip rings (6) and (6 ') are provided at the ends of the. As a result, the drive signals (power supply frequency) from the power supplies (5) and (5 ') via the slip rings (6) and (6') are not interrupted to the drive motors (4) and (4 '), respectively. It supplies continuously.

Next, reference numeral (7) represents a freely rotating contact roller, and the contact roller (7).
Is pressed against the yarn package (P) formed on the bobbin (3) inserted into the bobbin holder (2) and friction driven. Due to this frictional drive, the contact roller (7) is driven to rotate. Therefore, by detecting the number of rotations through the electromagnetic pickup (8), the winding speed of the yarn package (P) (external damage to the yarn package). The surface velocity of the surface) can be detected. Further, since the contact roller (7) is brought into pressure contact with the yarn package (P), it also has a role of giving an appropriate contact pressure to the yarn package (P) to improve its winding form. Is playing.

The contact roller (7) is attached to an elevating device (not shown) together with a traverse mechanism (not shown) for imparting a traverse motion at the time of winding, and is rotated by the elevating device. Since the package (P) is freely supported, the structure is such that the package (P) rises together with the lifting device while being in contact with the package (P) at a set contact pressure as the package (P) becomes thicker.

Further, a gear (7a) for detecting rotation is provided at the shaft end of the contact roller (7). An electromagnetic pickup (8) is provided on the frame (not shown) of the winder facing the gear (7a). By adopting such a configuration, when the gear (7a) rotates, the crests (the part where the teeth exist) and the troughs (the part where the teeth do not exist) of the gear (7a) become the electromagnetic pickup (8). Since the sensor portion is alternately approached, the number of times of approach is electromagnetically detected, and the rotation speed of the gear (4a) can be detected by counting the number of pulses of the detected electromagnetic signal. In this way, the rotation speed of the contact roller (7) (that is, the winding speed of the package (P) if the slip of the contact roller (7) is ignored) is detected by the electromagnetic pickup (8). It is possible. The winding speed signal of the package (P) detected through the electromagnetic pickup (8) is fed back to the winding speed control device (9) as an electric pulse. Then, according to the winding speed signal, the winding speed control device (9) sets the winding speed of the package (P) to a preset value (may be a predetermined pattern), The drive signal of the power supply (5) is controlled.

The drive motor (4 ') for driving the bobbin holder (2') in the standby state has the same power source (5 ') and winding speed as the bobbin holder (2). A control device (9 ') is provided. A rotation speed detecting gear (4'a) is provided at the shaft end of the bobbin holder (2 ') as in the case of the contact roller (7). Therefore, when either the bobbin holder (2) or (2 ') is rotated to the standby position,
The electromagnetic pickup (8 ') fixedly mounted on the winder frame (not shown) faces the gear (4a) or (4'a) provided at each shaft end thereof, and each bobbin holder (8a). The rotational speed of 2) or (2 ') can be detected.

In the embodiment shown in FIG. 1, the bobbin holder (2 ') is located at the standby position and the bobbin holder (2) is located at the winding position.
By rotating a), the standby position and the winding position of the bobbin holder (2 ') and the bobbin holder (2) can be switched alternately. In addition, to be on the safe side, FIG. 1 shows a state in which the electromagnetic pickup (8 ') and the rotation speed detecting gear (4a') are located opposite to each other. By rotating (1a), the rotating speed detecting gear (4
a) is replaced with the rotation speed detection gear (4a '), and the rotation speed detection gear (4a) and the electromagnetic pickup (8') are in a newly opposed state. In this way, the rotation speed signal of the bobbin holder (2) newly moved to the standby position by the rotation is detected by the electromagnetic pickup (8 ') and fed back to the winding speed control device (9'). .

Here, the changeover switches (10) and (1
0 '), when the drive motor (4') of the bobbin holder (2 ') and the drive motor (4) of the bobbin holder (2) exchange their positions by rotation, drive power sources (5) and ( In order to avoid the automatic replacement of 5 '), the dedicated power supplies (5') and (5) for supplying the drive motors (4 ') and (4) are provided for the purpose of switching each other. Has been.

Finally, (11) is a yarn switching control device, and a yarn switching command signal is transmitted from this yarn switching control device (11), whereby the above-mentioned changeover switches (10) and ( 10 ') is inverted.

The device configuration of the turret type automatic switching winder and the operation thereof have been described above, and the yarn switching method of the present invention will be described below with reference to FIG. 2 (method of the present invention) and FIG. 3 (conventional method). Will be described in detail with reference to.

In these FIGS. 2 and 3, A is the winding speed of the yarn package (P) being wound, B is the winding speed of the empty bobbin (3 ') on standby, and C is the contact roller ( 7) Rotational peripheral speed, and D shows the winding tension of the yarn at that time, and the horizontal axis shows time (timing).
Are taken (indicated by the solid lines, respectively). Also, FIG.
In the time chart showing the winding speed of the bobbin (3 ') in the standby state, the time chart shown by the solid line is generated by the conventional feedback control, while the broken line (B') shows The time charts shown are for each of the goals to be controlled.

2 and 3, point (a) is the start point of speed increase of the empty bobbin (3 '), point (b) is speed increase completion point of the empty bobbin (3'), and point (c) is. Start point of acceleration of yarn package during winding, (d) Start point of turret,
Point (e) is the completion point for speedup of the yarn package during winding,
Point (f) represents the stop point of the yarn traverse, and point (g) represents the contact point between the contact roller (7) and the empty bobbin (3 ').

Point (h) is a yarn switching point (maximum drop in yarn winding tension), point (i) is a yarn transfer completion point to the empty bobbin (3 '), and point (j). The point () is the restart point of the yarn traverse, the point (k) is the point at which the bobbin that has newly started winding returns to the steady winding speed, and the point (l) is the yarn package (P) after the winding is completed. The deceleration start point, the point (m) represent the start point of the feedback control, and the point (n) represents the rotation stop point of the yarn package (P) whose winding is completed.

Further, V is a steady winding speed during winding of the yarn package in a steady state, and V1 is an increased winding velocity after speedup when the yarn of the yarn package (P) being wound is switched. , V2 respectively represent the pre-winding speed of the empty bobbin (3 ') after acceleration. Further, F1, F2, and F3 respectively represent typical winding tensions of the yarns that characterize before and after the yarn switching.

The explanation of the reference numerals is completed as described above, and the change in the winding speed (A) of the yarn package being wound and the winding speed (B) of the empty bobbin in the waiting state will be described below in chronological order. A detailed description will be given.

First, at the point (a), when the winding amount of the yarn package (P) reaches a predetermined amount, the yarn switching control device (11) generates a yarn switching signal and stands by. The bobbin holder (2 ') is started at this point. Therefore, the empty bobbin (3 ') inserted into the bobbin holder (2') starts to accelerate the running speed together with the bobbin holder (2 ').

Then, at point (b) about 60 seconds later,
Empty bobbin (3 ') inserted in bobbin holder (2')
Has been increased to a predetermined winding speed set in advance, that is, the preliminary winding speed (V2). And this (b)
From the point, the winding speed of the bobbin holder (2 ') is compared with the signal fed back from the above-mentioned electromagnetic pickup (8') so that the winding speed control device (9 ') keeps a constant preliminary winding speed ( V2) is maintained.

On the other hand, the bobbin holder (2) to which the yarn package (P) being wound is mounted is
According to a command from the winding speed control device (9), the feedback signal output from the electromagnetic pickup (8) for detecting the rotation speed of the gear (7a) provides a preset constant winding speed (V). It is driven by a controlled drive motor (4).

Then, from point (b), a fixed time (about 5 seconds)
At point (c) after the lapse of time, the winding speed of the yarn package (P) inserted into the bobbin holder (2) starts to accelerate. At this time, the winding speed of the yarn package (P) is accelerated according to the speed increasing rate set according to the winding amount of the yarn package (P) by the control signal from the yarn switching control device (11), This acceleration is completed at the point (e) when the winding speed reaches the predetermined speed (V1).

Then, the winding speed reaches V1 (e)
At this point, the feedback control to the drive motor (4) that drives the bobbin holder (2) in which the yarn package (P) is inserted is temporarily stopped, and the frequency output from the drive power supply (5) is maintained at a constant value. By doing so, the winding speed of the yarn package (P) is maintained at a substantially constant speed (V1). Strictly speaking, during this period, the yarn package (P) has a slightly increased winding speed because the yarn package (P) continues to be wound thicker, but since the time during which the yarn package (P) is maintained at a constant speed (V1) is short, Therefore, the winding speed can be regarded as being maintained at V1.

In this way, the yarns are switched while the winding speed of the yarn package (P) is maintained substantially at V1. Then, after the switching of the yarns is completed, deceleration is started at the point (l), and finally the bobbin holder (2) completely stops rotating at the point (n).
When the bobbin holder (2) stops rotating, the wound yarn package (P) is replaced with an empty bobbin by hand or by an automatic doffer. Then, a new fully wound yarn package is formed on the other bobbin holder (2 '), and the yarn package is kept waiting until the yarn is switched again.

On the other hand, the winding speed of the empty bobbin (3 ') is changed from the point (g) at which the yarn is switched to the empty bobbin (3') where the yarn is switched and the winding is newly started. , Forcibly decelerated suddenly. It should be noted that this deceleration is performed in two stages in the embodiment of FIG. That is, the first stage is
The deceleration period from point (g) to point (i), and the second stage is the deceleration period from point (i) to point (k). The reason why the speed is reduced in two stages is that if the speed is rapidly reduced only in the first stage, the rotation inertial force of the bobbin holder causes poor control and the rotation of the bobbin holder cannot be accurately controlled. Therefore, the winding speed can be smoothly approached by slowing down the deceleration speed rapidly in the first step and slowing down the deceleration speed in the second step at point (i) when the speed has approached the control speed to some extent.

Above, the explanation of the speed change until the yarn package (P) completes the winding is completed. Below, focusing on the rotational peripheral speed of the contact roller (7), the speed change is time-series. Explained.

Since the contact roller (7) is initially in pressure contact with the yarn package (P) being wound and is frictionally driven, when the winding speed of the yarn package (P) starts to increase ( The constant winding speed (V) is maintained until c). Then, as the winding speed of the yarn package (P) increases from the point (c), the contact roller (7) that comes into pressure contact with the yarn package (P) and rotates together starts to accelerate.

However, at the point (d), the bobbin holder (2) in which the yarn package (P) is inserted and the bobbin holder (2 ') in which the empty bobbin (3') is inserted start turrets. Therefore, the contact between the contact roller (7) and the yarn package (P) is released.
For this reason, the frictionally driven contact roller (7)
Loses its drive source and begins decelerating. In this deceleration of the contact roller (7), the turret is started to switch the yarn, and the empty bobbin (3 ') and the contact roller (7) are pressed against each other and friction driven again (g) point. Continues until.

Then, the contact roller (7), which has started accelerating again by being frictionally driven by the rotating bobbin (3 ') from the point (g), starts accelerating again, but newly. Since the empty bobbin (3 ') on which the winding is started is decelerated, the speed of acceleration is gradually slowed down and gradually approaches the winding speed. The contact roller (7) gradually approaching the winding speed in this way has already reached a speed close to the steady winding speed that does not adversely affect the quality of the innermost layer yarn substantially in the vicinity of the point (j). . For this reason,
At points (k) and (m), even if the feedback control is started, there is almost no transient characteristic (hunting) associated with the feedback control, and the feedback control can be smoothly performed.

On the other hand, in the conventional method shown in FIG. 3, the feedback control by the contact roller (7) from the yarn switching point (g) is performed by the empty bobbin (3 ') which newly starts winding. Done against. However, even if the speed of the empty bobbin (3 ′) that has newly started winding starts deceleration at the point (g), the rotation speed of the contact roller (7) is still in the low speed state where the speedup has started. It is in. Therefore, in the winding speed control device (9 '), the rotation speed of the empty bobbin (3') is lower than the steady winding speed (V) based on the feedback signal from the contact roller (7). As a matter of fact, it plays the role of accelerating the empty bobbin (3 ') while it needs to decelerate. For this reason, the transient characteristics associated with the feedback control as shown at points (g) to (m) in FIG. 3 become remarkable, and the points (j) to (l) where the quality of the innermost layer yarn should be guaranteed. In the meantime, it becomes impossible to bring the winding speed close to the steady winding speed at which the quality can be guaranteed.

Finally, by tracking the winding tension of the yarn, which influences the quality of the wound yarn, in time series, the quality of the innermost layer yarn of the yarn package (P) and the yarn switching success. It is described below how the improvement of the rate and the guarantee of both are compatible.

2 and 3, the winding tension (D) of the yarn is determined by the traverse fulcrum guide (not shown) of the yarn when the yarn traverse is performed. It should be added that the measurement is performed by a known measuring device on the upstream side. Therefore, even if the yarn is switched from the fully wound bobbin (3) to the empty bobbin (3 '), the winding tension of the yarn continuously traveling from the upstream side to the downstream side is irrespective of these operations. You can always measure online.

In FIG. 2, the winding tension of the yarn is the tension (F0) while the yarn package (P) being wound is at the constant winding speed (V). The reason why the tension has a small vibration waveform is that the yarn being wound is traversed and wound up. When the winding speed (A curve) of the yarn package during winding starts to rise at point (d),
Along with this, the winding tension also rises. Then, at the point (e) where the speedup is completed, the increase of the winding tension is also completed.

Next, at the point (f), the yarn traversed so far is removed from the traverse guide by the operation of the yarn removing device (not shown), and the traverse of the yarn is stopped. Therefore, after the point (f), the small vibration waveform due to the yarn traverse disappears. The tension of the yarn at this time is F1.

Further, the turret table (1a) is rotated from the point (d) by the electric motor (1c) to replace the waiting bobbin holder (2 ') with the winding position.
However, during the rotation of the turret, the yarn is caught in the catching groove of the empty bobbin inserted in the waiting bobbin holder (2 ') at or immediately before the point (g), and the yarn switching is performed. Be seen. At this time, the winding tension of the yarn is
At point (h), the value instantaneously drops to the minimum (F2). Since the yarn is newly wound on the empty bobbin (3 ') by the switching of the yarn, the winding tension of the yarn is set to the empty bobbin (3) at which the new winding is started. It depends on the winding speed (B curve) of ′) and has no relation to the winding speed (A curve) of the yarn package (P) that has been wound.

Here, from the point (g) to the point (k), the winding of the yarn is switched, and a new winding starts and the speed of the empty bobbin (3 ') is gradually reduced to drive. The frequency output from the power source (5 ') and held therein is forcibly reduced in a predetermined pattern. Then, the frequency of the drive power source (5 ') is controlled so as to match the frequency of the steady winding speed (V) when the turret is completed. At point (h) during the gradual decrease of the frequency, the bobbin holder (2 ′) has not reached the set rotational speed,
The winding tension of the yarn goes through the peak at point (i). It should be noted that point (i) is usually a fixed time (about 3 seconds) from point (g).
It is set to come later.

However, the peak tension at this time can be suppressed to a low value because the winding speed of the bobbin (3 ') where the winding of the yarn is newly started has already been gradually reduced. Is a big feature of. On the other hand, it is needless to say that the conventional method cannot suppress the winding tension at this time to a low level because of the transient characteristic associated with the feedback control as described above.

In this way, at a point (j) after a fixed time (about 5 seconds) after the yarn switching is completed, the yarn removing device is operated to restore the traverse of the yarn, and thereby the yarn is re-driven. Start the article traverse. At this time, the winding tension (F3) of the yarn is almost equal to the steady winding tension (F0) because the winding speed has already reached the steady winding speed (V). In this way, the yarn formed in the innermost layer of the yarn package by the yarn traverse is wound with a winding tension substantially equal to the steady winding tension (F0), so that the quality of the innermost layer yarn is improved. It is guaranteed.

Next, the relationship between the behavior of the winding tension of the yarn and the yarn switching success rate will be described in more detail.

That is, at the point (f), the yarn being wound off from the traverse guide is caught at the point (g) by engaging with the catch groove of the yarn provided on the empty bobbin. The yarn is switched by. When switching between these yarns,
As described above, the winding tension of the yarn greatly decreases for a moment.

If the tension (F1) immediately before the point (g) is not set within an appropriate range, the automatic switching success rate will decrease. Therefore, in order to increase the yarn switching success rate, Regarding the winding speed of the yarn package (P) being taken, it is important to control the tension (F1) immediately before this point (g). Further, in order to minimize the decrease in the winding tension at the point (h) at the time of delivering the yarn to the empty bobbin (3 ′), increase the preliminary winding speed of the empty bobbin (3 ′). ,
It is necessary to compensate for the tension (F2) that decreases at point (h). In this manner, the winding tension (F1) can be compensated and controlled within an appropriate range, and the reduction of the winding tension at the point (h) can be minimized, and the empty bobbin (3 ')
Once the yarn has been caught in the catching groove, there is no need to maintain a high winding speed of the empty bobbin (3 ') which has newly started winding, and it is rather harmful.

For this reason, if the yarn is caught in the yarn catching groove of the empty bobbin (3 '), new winding is started in order to guarantee the quality of the innermost layer yarn of the yarn package. Preliminary winding speed (V2) of the bobbin that has been taken is the steady winding speed (V)
The maximum tension (F3) at the point (h) may be kept low by gradually decreasing the amount to (1). To this end, the method of the present invention has a very remarkable effect,
As I have repeated.

[0055]

As described above, according to the present invention, in the conventional method, even if an attempt is made to improve the success rate of yarn switching which has been lowered due to the denier of the yarn or the change in the winding amount of the package, Winding tension (F1), which was difficult in terms of quality, because the yarn quality of the innermost yarn of the yarn package deteriorated.
As in the conventional method, the yarns can be switched while maintaining a high value. Therefore, according to the method of the present invention, it is possible to significantly improve the success rate of yarn switching, and further, it is possible to minimize the deterioration of the yarn quality of the innermost layer yarn of the yarn package. It has an extremely large effect.

[Brief description of drawings]

1 is a schematic perspective view of an apparatus for carrying out the present invention.

FIG. 2 illustrates a winding speed (A) of a yarn package, a winding speed (B) of a bobbin in a standby state, a rotational peripheral speed (C) of a contact roller, and a yarn at this time for explaining the present invention. It is a time chart of the winding tension (D) of the strip.

FIG. 3 illustrates a winding speed (A) of a yarn package, a winding speed (B) of a bobbin in a standby state, a rotation peripheral speed (C) of a contact roller, and a winding speed (A) of the yarn for explaining a conventional method. It is a time chart of the winding tension (D) of the yarn.

[Explanation of symbols]

 1a Turret table 2 Bobbin holder 2'Bobbin holder 3 Bobbin 3'Bobbin 4 Electric motor 4'Electric motor 5 Drive power supply 5'Drive power supply 7 Contact roller 8 Rotation speed detector 9 Winding speed control device 9'Winding speed control device 11 Thread switching controller V Steady winding speed V1 Winding speed of yarn package after acceleration V2 Pre-winding speed (empty bobbin)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Seiji Yoshioka 77 Kitayoshida-cho, Matsuyama-shi, Ehime Prefecture Matsuyama Factory, Teijin Seiki Co., Ltd. (72) Yuichi Masaoka 77 Kitayoshida-cho, Matsuyama-shi, Ehime Made by Teijin Machinery Company Matsuyama Factory

Claims (1)

[Claims] 1. When two bobbin holders, each having a bobbin inserted therein, are arranged on a turret, and when a yarn package having a predetermined winding amount is formed on one bobbin, the turret is rotated to rotate the other bobbin holder. In a yarn switching method of a turret type automatic switching winder for automatically switching a yarn to a bobbin, the yarn package is wound by being pressed against the outer peripheral surface of the yarn package being wound and frictionally driven. A contact roller for detecting the winding speed is provided, and when the winding is completed, the winding speed signal detected by the contact roller is fed back to the driving device of the bobbin holder during winding, so that the winding speed of the bobbin holder is constantly wound. The winding speed is increased from the winding speed to the preset winding speed, and the turret is rotated from the yarn package being wound to the empty bobbin that has been pre-accelerated to the normal winding speed or faster. When changing the yarn, the feedback control of the winding speed to the bobbin holder into which the yarn package being wound is inserted is temporarily stopped by the winding speed signal detected by the contact roller, and after changing the yarn. , For the bobbin where the winding of the yarn is newly started, the winding speed of the bobbin is forcibly reduced stepwise or continuously until the traverse of the yarn is restarted. , Substantially returning to the steady winding speed, and then for the bobbin where the winding of the yarn is started,
A turret type automatic switching winder, which restarts the feedback control of the winding speed to the bobbin holder in which the yarn package being wound is inserted, based on the winding speed signal detected by the contact roller. Yarn switching method.