JPH07157929A - Method for cutting winding tail of roving and cutter in doffing in roving frame - Google Patents

Abstract

PURPOSE:To provide a part for starting the winding onto the next bobbin with the number of twists comparable to that in usual spinning even when the hard twisting of a roving is carried out so as to cut the roving at a suitable position in doffing. CONSTITUTION:This method for cutting the roving winding tail in doffing is to rotate a flyer 4 and a bobbin (B) at the same speed in a state of front rollers 1 stopped from rotating in doffing, apply stronger twist than that in usual spinning to a roving (R) between the front rollers 1 and the flyer top (4a), then rotate the front rollers 1, deliver the roving (R), simultaneously wind the delivered roving (R) onto the bobbin (B), move the hard twisted part of the roving (R) into flyer legs (4b), further deliver the roving (R) in a state of carrying out no winding from the front rollers 1, loosen the roving (R) between the front rollers 1 and the flyer top (4a), subsequently lower a bobbin rail 8, automatically cut the roving (R) at a prescribed position emerging from a presser strap (30a) and then rotate the flyer 4 in the direction opposite to the twisting of the roving (R) in usual spinning by a prescribed number of turns to return the twists in the hard twisted part of the roving (R) to the original state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for cutting a roving winding tail at the time of doffing in a roving machine.

[0002]

2. Description of the Related Art In a roving machine, it is always necessary to cut the bobbin winding tail of a bobbin somewhere during doffing work associated with a full pipe. Then, when considering the next winding work, the cutting position is an appropriate length (50 to 6) from the tip of the battledore of the presser.
It is desirable to cut while leaving 0 mm). This roving cutting is performed by lowering the full-filled yarn from the ascending / descending range during spinning to a predetermined position for doffing, when doffing is accompanied by a full pipe. At this time, since the tension generated in the roving yarn is maximum at the portion of the presser that exits the battledore, the roving yarn is naturally cut at a position of 50 to 60 mm from the tip of the battledore. However, a relatively large fiber such as a synthetic fiber having a long fiber length and a high roving strength is not cut at this desired portion, and is often cut between the front roller and the flyer top or in the pipe of the flyer leg.

To solve this problem, Japanese Unexamined Patent Publication No. 1-97
No. 225 and JP-A-3-193938, before lowering the bobbin rail, the roving thread connected to the arm part of the presser from the front roller is twisted more strongly than usual, except for the predetermined part immediately after exiting the presser battledore. There is disclosed a method of preventing the cutting of roving yarn in the above. For example, Japanese Patent Laid-Open No. 3-1
In Japanese Patent No. 93938, first, immediately before doffing, the bobbin is rotated at the same rotation speed as the flyer for a short time while the roving feed from the front roller is stopped, and the bobbin is stretched between the front roller and the flyer top. It gives a stronger twist to the existing roving than that given to the roving during normal spinning. After that, the roving yarn is sent out from the front roller, and the roving yarn is wound until the portion where the hard twist between the front roller and the flyer top moves into the pipe of the flyer leg, and then the winding is stopped. The roving is sent out from the front roller with and looseness of the roving is provided between the front roller and the flyer top. Then, by lowering the bobbin rail, the roving yarn is cut at a portion immediately after exiting the presser battledore.

According to this method, the roving thread reaching the front roller and the presser arm is twisted to a greater extent than the twist applied to the roving thread during normal spinning, and the roving thread strength at this portion is relatively high. In addition, the roving is loose between the front roller and the flyer top. Therefore, when the bobbin rail descends to a predetermined position for doffing, even if the tension applied to the roving yarn as the bobbin rail descends reaches the roving yarn from the flyer top to the front roller 5, the tension of the roving yarn is Since it is absorbed by the looseness, the roving is naturally cut at a position of 50 to 60 mm from the tip of the battledore. In this way, the next automatic winding of the roving becomes possible.

[0005]

By the way, after the roving is cut, the roving from the front roller to the presser battledore is in a state in which a greater twist is added than in the normal spinning. Then, with the doffing, the strongly twisted portion is first wound around the bobbin newly mounted on the spindle. Conventionally, the roving wound on the bobbin has not been used up to the end, and the strong twist portion of the roving has not been used as a residual roving.

However, it is a waste of roving that the roving wound on the bobbin is not used up in the spinning process and is used as a residual roving, and it is desired to use up all the roving wound on the bobbin. There is. However, when trying to use up the roving to the end, the strong twist part of the roving that is first wound on the bobbin is also drafted in the spinning process, but the strong twist part is twisted more strongly than usual, so it is sufficient. There was a risk that the spun yarn would not be drafted, and a defect due to defective draft might occur. Further, when the roving wound on the bobbin is used up to the end, there is a risk of draft failure, so the number of twists for applying the strong twist is limited to some extent.

The present invention has been made in view of the above problems, and an object thereof is to start winding on the next bobbin even if a strong twist is made to cut the roving yarn at an appropriate position during doffing. The number of twists of the part can be made to be about the same as during normal spinning, and the roving wound on the bobbin can be used up to the end. To provide.

[0008]

In order to achieve the above object, in the invention according to claim 1, the bobbin is made in a state in which the roving thread extending from the front roller to the flyer is twisted more strongly than in normal spinning at the time of doffing. In the method of cutting the roving winding tail at the time of doffing in a roving machine that lowers the rail and cuts the roving yarn near the exit of the presser board of the presser, after cutting the roving yarn, after the roving yarn cutting, a strong twist applied to the roving yarn by the flyer is applied. It was designed to rotate a predetermined amount in the returning direction. Here, it is desirable that the twist of the roving is returned to the same level as in the ordinary spinning.

According to the second aspect of the present invention, after stopping the machine for doffing or immediately before stopping the machine, the bobbin is rotated at the same rotational speed as the flyer while the roving feed from the front roller is stopped. An operation in which the roving thread stretched between the front roller and the flyer top is rotated for a period of time to give a stronger twist than the twist given to the roving thread during normal spinning, and a strong twist between the front roller and the flyer top. After carrying out the operation of winding the roving yarn to send out the sewn portion and the operation of providing a predetermined slack in the roving yarn stretched between the front roller and the flyer top, the bobbin rail is fried. Then, the roving yarn is cut near a position where the presser board of the presser has exited, and the fried yarn is rotated by a given amount in the direction in which the strong twist given to the roving yarn is returned after the roving yarn is cut.

According to another aspect of the invention, there is provided main driving means for driving the front roller and the flyer at a predetermined rotation ratio and at least driving the flyer so that the flyer can rotate forward and backward.
Switching means capable of switching between a connection state in which the front roller and the main drive means are operatively connected and a disconnection state in which the operation connection between the front roller and the main drive means is cut off, and a spindle in the same direction as the flyer. A spindle drive means capable of driving a non-winding state in which the spindle can be rotated at the same speed, and a winding state in which the spindle can be rotated in the same direction as the flyer at a higher winding speed than the flyer,
A bobbin rail drive means for lowering the bobbin rail from the full pipe stop position to the doffing position, and a control device for driving and controlling the main drive means, the switching means, the spindle drive means and the bobbin rail drive means are provided.

[0011]

According to the invention of claim 1, at the time of doffing,
The roving thread that extends from the front roller to the flyer is twisted more strongly than during normal spinning, and the bobbin rail is lowered from that state. As a result, the roving is cut near the exit of the press board of the presser. After the roving is cut, the flyer is rotated by a predetermined amount in the direction of returning the strong twist previously applied to the roving, and is returned to the same twist strength as that in the normal spinning, for example. Then, the roving yarn is wound onto the next new bobbin in a state where the winding start end portion is not strongly twisted. Therefore, even if the roving wound on the bobbin in the next spinning process is used up to the end, the spun yarn does not have a defect such as a draft defect.

According to the second aspect of the invention, the bobbin is rotated at the same rotational speed as the flyer in a state in which the roving feed from the front roller is stopped after the machine stand for doffing is stopped or just before the machine stand is stopped. Then, the roving thread stretched between the front roller and the flyer top is rotated for a short time to give a stronger twist than the twist given to the roving thread during the normal spinning. Next, a roving winding operation is performed to send out the strongly twisted portion between the front roller and the flyer top, and an operation for providing a predetermined slack in the roving stretched between the front roller and the flyer top. Done. At the end of these three operations, the roving thread from the front roller to the presser arm of the flyer is twisted stronger than in the normal spinning process and is stretched between the front roller and the flyer top. A predetermined slack is provided in the roving. When the bobbin rail is lowered to the predetermined position during doffing in this state, the tension is applied to the roving yarn between the flyer top and the front roller at the beginning of the descent, and the roving yarn is in a loose state. The tension applied to is absorbed by the reduced slack. Therefore, the roving yarn is automatically cut in the vicinity of exiting the battlement plate of the presser while descending.
Then, after the roving is cut, the flyer is rotated by a predetermined amount in the direction in which the strong twist given to the roving is returned, and the twist of the portion that has been previously strongly twisted is returned. As a result, the roving yarn is wound on the next bobbin without the strong twisting portion at the winding start end, so even if the roving yarn wound on the bobbin in the spinning process is used up, the spun yarn is spun. No problems such as draft defects will occur.

According to the third aspect of the invention, the main drive means, the switching means, the spindle drive means, and the bobbin rail drive means are drive-controlled by the drive control means, for example, as follows. That is, after stopping the machine for doffing or just before stopping the machine, the main drive means is driven so that the flyer rotates in the forward direction while the switching means is in the cutoff state, and at the same time, the spindle drive means. Is driven in a non-winding state.
As a result, the rotation of the front roller is stopped and the flyer and the spindle rotate forward at the same speed while the roving is not wound onto the bobbin, and the roving normally stretched between the front roller and the flyer top is normally spun. An operation is performed to apply a stronger twist than at the time of delivery. Further, with the switching means in the connected state, the spindle drive means together with the main drive means are driven for a predetermined time in the winding state. As a result, the operation of sending out the roving is performed until the portion where the strong twist between the front roller and the flyer top reaches the inside of the pipe of the flyer leg. Further, the bobbin rail driving means is driven to lower the bobbin rail from the machine base stop position. During this descent, the roving is automatically cut near the exit of the presser's battlement plate.
After the roving is cut, the main drive means is driven so that the flyer rotates in the reverse direction with the switching means in the cutoff state. As a result, the operation of returning the strong twist previously applied to the roving is performed while the rotation of the front roller is stopped. Therefore, the invention described in claim 1 can be implemented.

Further, if the drive control device performs the following drive control, the invention described in claim 2 can be implemented. That is, in addition to the above-mentioned operation, before the bobbin rail is lowered, the main drive means is driven for a predetermined time while the switching means is connected and the spindle drive means is driven in the non-winding state. It As a result, the roving yarn is fed from the front roller in a state where the roving yarn is not wound up, and it is possible to provide the slack yarn stretched between the front roller and the flyer top with a slack larger than that during normal spinning. Done.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. The drive system of the roving spinning machine in the present embodiment has basically the same configuration as that previously proposed by the applicant of the present application (Japanese Patent Laid-Open No. 5-71022).
It consists of a winding drive system and a lifting drive system. Each drive system has a different variable speed motor. In this embodiment, the drive system of the front roller can be separated from the drive system of the flyer and the spindle.

First, the drive system of the roving frame will be described with reference to FIG. The front roller 1 is a belt arranged between a driven gear 2 fitted to one end of a rotary shaft 1a thereof and a driving shaft 3 which is rotationally driven by a main motor M constituting a spindle driving means and a main driving means. It is adapted to be rotationally driven via a transmission mechanism and a gear train (neither is shown). A driven gear 5 is fitted and fixed on the upper portion of the flyer 4 so as to be integrally rotatable. The rotation of the driving shaft 3 is transmitted through a belt transmission mechanism (not shown) to the rotation of the rotary shaft 6, and the driven gear 5 is rotated together with the flyer 4 via the drive gear 7 fitted to the rotary shaft 6. Driven. On the other hand, a driven gear 9a is fixed to a spindle 9 mounted on the bobbin rail 8. A rotary shaft 11 to which a drive gear 10 meshing with the driven gear 9a is fitted and fixed, and a rotational motor of the driving shaft 3 and a winding motor 13 which is driven at a variable speed via an inverter 12b.
The rotational force due to is combined and transmitted by the differential gear mechanism 14 which constitutes the spindle drive means. The winding motor 13 is speed-changed so as to reduce the rotation speed of the bobbin B mounted on the spindle in response to the increase in the roving winding layer. When the bobbin B is driven in a state where the winding motor 13 is stopped, that is, when there is no input from the winding motor 13 to the differential gear mechanism 14, the rotation speed of the bobbin B is the rotation speed of the flyer 4. Is set to be the same as.

A lifter rack 15 is fixed to the bobbin rail 8. Gear 1 that meshes with lifter rack 15
The rotation of the drive shaft 18 is transmitted to the rotary shaft 17 to which 6 is fitted via a switching mechanism 19 and a gear train that constitute a bobbin rail drive means. The drive shaft 18 is driven by an elevating motor 20 which constitutes a bobbin rail drive means which is variable-speed driven via an inverter 12c. The switching mechanism 19 includes an intermediate shaft 21, a pair of gear trains 22 and 23 provided between the intermediate shaft 21 and the drive shaft 18, and the gear trains 22 and 23.
Clutches 24, 25 for transmitting the rotation of the intermediate shaft 21 to the intermediate shaft 21
It consists of and. Then, the electromagnetic clutches 24, 2
The direction of rotation of the rotary shaft 17, that is, the direction of vertical movement of the bobbin rail 8 is changed by the excitation / demagnetization of 5. A rotary encoder 26 is connected to the end of the rotary shaft 17 to detect the vertical movement direction and movement amount of the bobbin rail 8.

An electromagnetic clutch 27 is provided in the middle of the drive system of the front roller 1 as switching means for connecting and disconnecting the operating connection between the gears. The front roller 1 is operatively connected to the driving shaft 3 when the electromagnetic clutch 27 is excited, and the drive system of the front roller 1 is disconnected from the drive system of the flyer 4 when the electromagnetic clutch 27 is demagnetized. That is, in the demagnetized state of the electromagnetic clutch 27 when the main motor M is driven, the driving of the front roller 1 is stopped and only the flyer 4 and the spindle 9 are driven.

A rotation speed sensor 28 for detecting the rotation speed of the front roller 1 is provided in the vicinity of the driven gear 2 which rotates integrally with the front roller 1. A rotation speed sensor 29 for detecting the rotation speed of the flyer 4 is provided near the driven gear 5.
Is provided. The roving R delivered from the front roller 1 is guided from the flyer top 4a through the yarn guide tube to the flyer leg 4b as shown in FIG. 1, and further from below the flyer leg 4b to the bobbin B via the presser 30. Have been guided. The main motor M and the winding motor 13
And the lifting motor 20 are inverters 12a, 1 respectively.
Control device 3 as drive control means via 2b and 12c
The drive is controlled by 1. Further, the main motor M can rotate forward and backward.

Next, a control circuit for driving and controlling the drive system will be described with reference to FIG. The microcomputer 32 constituting the control device 31 is a central processing unit (hereinafter referred to as CP
33), a program memory 34 including a read-only memory (ROM) storing a control program,
Input data input by the input device 35 and the CPU 3
3 is a working memory 36 which is a readable and rewritable memory (RAM) for temporarily storing the arithmetic processing result and the like. The CPU 33 operates based on the program data stored in the program memory 34.

An input device 35 for inputting spinning conditions such as spun roving weight (gel) g, fiber type, and twist number is integrally incorporated in the control device 31 as a keyboard. Output signals from the rotary encoder 26 and the rotation speed sensors 28 and 29 are sent to a CPU 33 via an input interface 37.
It is designed to be input to.

The electromagnetic clutches 24 and 25 are the CPU 33.
The excitation / demagnetization of the bobbin rail 8 is controlled through the electromagnetic clutch excitation / demagnetization circuit 38 on the basis of the signal from the above, and the up / down switching of the bobbin rail 8 is performed. The CPU 33 also includes an output interface 39, motor drive circuits 40a, 40b,
The main motor M, the winding motor 13 and the lifting motor 20 are driven via the inverter 40c and the inverters 12a, 12b and 12c. The electromagnetic clutch 27 is C
Based on a signal from the PU 33, the excitation / demagnetization is controlled via the electromagnetic clutch excitation / demagnetization circuit 41, and the front roller 1
Is connected to and disconnected from the drive system of the flyer 4 and the spindle 9. The CPU 33 controls each control signal KS, MS, D +, D- WS, LS as shown in the time chart of FIG.
The motor drive circuits 40a to 40c and the excitation / demagnetization circuits 3
It outputs to 8 and 41.

The electromagnetic clutch 27 is excited when the excitation / demagnetization signal KS input to the electromagnetic clutch excitation / demagnetization circuit 41 is at H level, and demagnetized when it is at L level. The main motor M is driven when the main motor drive signal MS input to the main motor drive circuit 40a is at H level, and stopped when it is at L level. Further, the main motor drive circuit 40a
A normal rotation signal D + and a reverse rotation signal D- are input to the main motor M, and the main motor M rotates normally when the main motor drive signal MS is at the H level and the normal rotation signal D + is at the H level. Is set to reverse when is at H level. Further, the winding motor 13 is driven when the winding motor drive signal WS input to the winding motor drive circuit 40b is at the H level, and stopped when the winding motor drive signal WS is at the L level. And
The elevating motor 20 is driven when the elevating motor drive signal LS input to the elevating motor drive circuit 40c is at the H level, and is stopped when the elevating motor drive signal LS is at the L level. Incidentally, when a series of operations associated with the cutting of the roving winding tail is performed after the pipe is full, the main motor M is operated at a sufficiently low speed V as compared with the spinning operation.

Next, the operation of the device configured as described above will be described. The electromagnetic clutch 27 is energized during the spinning operation of the machine base. The main motor M, the winding motor 13, and the lifting motor 20 are each predetermined based on the spinning conditions such as the spun roving weight (gel) g, the fiber type, and the twist number that are input prior to the start of the machine operation. It is driven at the rotation speed of. By the rotation of the driving shaft 3 based on the driving of the main motor M, the front roller 1 and the flyer 4 rotate at a constant speed at a predetermined rotation ratio. The rotation of the driving shaft 3 based on the drive of the main motor M and the rotation based on the drive of the winding motor 13 are combined in the spindle 9 by the differential gear mechanism 14 at a speed corresponding to the winding diameter of the bobbin B at each time point. It is driven at variable speed. On the other hand, the bobbin rail 8 is the electromagnetic clutch 2
It is moved up and down based on the excitation and demagnetization of 4, 25. The roving R spun from the front roller 1 in this manner is wound around the bobbin B. During the spinning operation, as shown in FIG. 6, the excitation / demagnetization signal KS, the main motor drive signal MS, the forward rotation signal D +, the winding motor drive signal WS and the lift motor drive signal LS are at H level, and the reverse rotation signal D -Is at L level. or,
During the spinning operation, the CPU 33 counts the number of counts based on the detection signal of the rotation speed sensor 28.

When the count number based on the detection signal of the rotation speed sensor 28 reaches a value corresponding to the roving length obtained from the spun roving weight (gel) g, it is determined that the roving winding is full. The motor drive circuits 40a, 40b, 4 are determined.
The deceleration signal DS is output to 0c. The main motor M, the winding motor 13, and the lifting motor 20 synchronously decelerate based on the deceleration signal DS until the main motor M decelerates to a predetermined speed V. During that time, the rotation speed of the main motor M is measured based on the output signal from the rotation speed sensor 29, and when the main motor M decelerates to a predetermined speed V, as shown in FIG. 6, an excitation / demagnetization signal KS and a winding motor drive signal WS. And the L level is output as the lifting motor drive signal LS (time T1 in FIG. 6). As a result, the up-and-down movement of the bobbin rail 8 is stopped, the electromagnetic clutch 27 is demagnetized, the power transmission to the front roller 1 is interrupted, and the rotation of the front roller 1 is stopped. Further, the drive of the winding motor 13 is stopped and the bobbin B rotates at the same speed as the flyer 4.

That is, as shown in FIG. 1A, the bobbin B rotates in the same forward rotation direction as the flyer 4 at the same rotation speed N1 in a state where the front roller 1 is not rotated and the feeding of the roving R is stopped. Is rotated. In this state, the speed of the roving layer surface on the bobbin B and the surface speed of the presser battledore 30a are the same, and the roving R is not wound and is stretched between the front roller 1 and the flyer top 4a. Twist that is stronger than the twist that is added during normal spinning is applied to the roving R.
Since the roving R is twisted once for one rotation of the flyer 4, the twist number is recognized by measuring the flyer rotation number based on the output signal of the rotation number sensor 29.

When the predetermined number of twists is reached, both H level is output as the excitation / demagnetization signal KS and the winding motor drive signal WS as shown in FIG. 6 (time T in FIG. 6).
2). As a result, the electromagnetic clutch 27 is excited again, the rotational force of the main motor M is transmitted to the front roller 1, and the winding motor 13 is rotationally driven at a predetermined speed corresponding to the rotational speed V of the main motor M. . That is, as shown in FIG. 1B, the front roller 1 is rotated to send out the roving R, and the rotation based on the drive of the winding motor 13 is input to the differential gear mechanism 14, whereby the bobbin B is rotated. Is rotated at a rotation speed N2 (> N1) capable of winding the roving R fed from the front roller 1. Then, the roving R fed from the front roller 1 is wound around the bobbin B. The winding of the roving R is performed before the portion where the strong twist is first reached the arm 30b of the presser 30, and the winding amount is the roving R fed from the front roller 1.
Equal to the length L of the rotation speed sensor 28 and is measured by the output signal from the rotation speed sensor 28.

When the count number based on the output signal of the rotation speed sensor 28 reaches a value corresponding to the predetermined feeding length L of the roving R, as shown in FIG. 6, the take-up motor drive signal WS is at the L level. Is output (time T3 in FIG. 6),
The drive of the winding motor 13 is stopped. As a result,
As shown in (a), the bobbin B rotates again at the same rotation speed N1 as the flyer 4, and the winding of the roving R fed from the front roller 1 is stopped. Winding motor 13
Is stopped at a low speed because it is rotating at a low speed, and the strongly twisted portion of the roving R is held at an appropriate position in the presser leg 4b. The front roller 1 and the flyer top 4
The number of twists per unit length decreases while the portion that has been strongly twisted with a moves into the presser leg 4b, but since this decrease is expected in advance, the required number of twists is secured. .

When the drive of the winding motor 13 is stopped, the roving R
Even after the winding of the front roller 1 is stopped, the front roller 1 is still in the rotating state, and as shown in FIG.
The roving R is continuously fed from the. As a result, slack is generated in the roving R stretched between the front roller 1 and the flyer top 4a. When a predetermined amount of slack has occurred, an L level is output as the main motor drive signal MS and an H level is output as the lift motor drive signal LS (time T4 in FIG. 6). As a result, the drive of the main motor M is stopped, the flyer 4 and the bobbin B quickly stop their rotation, and at the same time, the drive of the lifting motor 20 is started. In the switching mechanism 19, the electromagnetic clutch 25 for descending is in an excited state, and the bobbin rail 8 descends as the lifting motor 20 is driven. And bobbin rail 8
Fig. 2 (b) during the process of descending to the predetermined position during the doffing.
As shown in, the roving R is automatically cut at the optimum position in the vicinity (50 to 60 mm) of the presser battledore 30a.

Immediately after the bobbin rail 8 descends, a certain amount of slippage occurs between the presser battledore 30a and the arm portion 30b and the roving R wound around the presser battledore 30a, and the front roller 1 passes through the inside of the flyer 4. The continuous roving R is pulled. However, the roving thread R between the front roller 1 and the flyer top 4a has an appropriate slack, and the roving thread R between the front roller 1 and the arm portion 30b has a stronger twist than in the normal spinning. Because
The roving R is not cut during this time, and only the slack is absorbed. Then, when the bobbin rail 8 descends to some extent, tension is directly applied to the roving R in a free state (a state in which it floats from the roving layer) immediately after leaving the presser battledore 30a, so that the presser battledore 30a is removed. The roving R is cut at the optimum position in the vicinity (50 to 60 mm) from which the roving R comes out.

When the bobbin rail 8 reaches a predetermined position for doffing, as shown in FIG. 6, the lifting motor drive signal LS falls from H level to L level and the reverse rotation signal D- becomes H level, so that the main motor is driven. H as drive signal MS
The level is output (time T5 in FIG. 6). As a result, the bobbin rail 8 is stopped at a predetermined position during doffing. or,
The main motor M is reversely driven at a low speed V, and as shown in FIG. 3, the flyer 4 and the bobbin B have the same rotation speed N1 in the direction opposite to the twisting direction during the spinning operation with the rotation of the front roller 1 stopped. To rotate. When the flyer 4 is rotated in the reverse direction, the flyer rotation speed is counted based on the output signal from the rotation speed sensor 29, and the flyer 4 is rotated in reverse until the count value reaches a value corresponding to the number of twists added to the roving R during the strong twist. Driven. Due to the reverse operation of the flyer 4, the strong twist that has been added to the roving R from the front roller 1 to the presser battlement plate 30a through the flyer 4 is returned, and the roving R from the front roller 1 to the presser battlement plate 30a is returned.
The number of twists is about the same as the number of twists during normal spinning. Further, the roving R after cutting is in a free state, and the twist in the releasing direction of the twist given to the roving R is also transmitted to the roving R in the flyer 4, and the strong twist added to the roving R is It is returned almost evenly. When the flyer 4 reverses, the bobbin B also reverses at the same speed.

When the count value based on the output signal from the rotation speed sensor 29 reaches a value corresponding to the number of twists added to the roving R during the strong twist, both the main motor drive signal MS and the reverse rotation signal D- are output. The L level is output (time T6 in FIG. 6). As a result, the rotation of the flyer 4 in the reverse rotation direction is stopped. Further, the rotation of the bobbin B, which has been reversed at the same speed when the flyer 4 is reversed, is also stopped.

At the beginning of winding of the roving R wound on the next bobbin B, no strong twist portion remains, and the number of twists is about the same as in the normal spinning. Even if it is used up to the end in the spinning process, there is no strong twist part, so it can be reliably drafted to the end. Therefore, as described in the prior art, the strong twisted portion of the roving R is not drafted in the spinning process and a problem does not occur in the spun yarn.
It is possible to use up the roving roll to the end. Therefore, it is possible to effectively use the roving R produced in the roving process without waste by using up all the roving R wound on the bobbin B and eliminating the residual roving.

Further, since the strong twist added to the roving R at the time of cutting the winding end of the roving is returned later, the number of twists for the strong twist is as many as necessary without considering draft defects in the spinning process. You can do a lot. Therefore, the number of twists for strong twisting can be set to the optimum number without considering draft defects as in the conventional case, so that the roving R is surely cut at a desired position out of the presser battledore 30a, and the roving is surely cut. The success rate of automatic cutting can be further improved.

The present invention is not limited to the above embodiment, and may be modified as follows, for example, without departing from the spirit of the present invention. (1) In the above embodiment, the spinning drive system, the winding drive system, and the lifting drive system were driven by separate motors M, 13, 20.
Each drive system may be driven by one motor or two motors. Further, the present invention may be applied to a roving machine equipped with a speed change mechanism using a cone drum instead of the winding motor 13 (for example, Japanese Patent Laid-Open No. 3-193938).

(2) The order of performing the operations of strong twisting, roving yarn feeding, and slack yarn slack formation can be appropriately changed. For example, after the strong twist is applied, the roving yarn is sent from the front roller 1 to loosen the roving yarn excessively, and then the strong twisting part is moved into the flyer leg 4b so that the slackness of the roving yarn remains appropriate. Alternatively, the roving yarn may be loosened and then the strong twist may be applied, and then the strong twist portion may be fed into the flyer leg 4b.
Also, two of the above operations may be performed in parallel at the same time. For example, the roving yarn feeding operation and the roving yarn slack forming operation may be performed in parallel, or the strong twisting operation and the roving yarn slack forming operation may be performed in parallel.

(3) The number of rotations of the flyer 4 at the time of strong twist may be appropriately changed depending on the type of yarn such as cotton or synthetic fiber. (4) Although the flyer 4 can be rotated in the reverse direction by using the variable speed motor capable of rotating in the forward and reverse directions as the main motor M in the above embodiment, the method of rotating the flyer 4 in the reverse direction can be appropriately changed. For example, a pair of gear trains for forward and reverse rotation and a clutch for switching the connection of the gear trains may be provided in the flyer drive system, and the flyer 4 may be capable of forward and reverse rotation by switching the clutches.

(5) The present invention may be applied to a case where the roving thread stretched between the front roller 1 and the flyer top 4a is not provided with slack and the bobbin rail 8 is lowered to automatically cut the roving thread. . In addition, depending on the type of yarn, slack is not provided for roving that has a relatively short fiber length such as cotton and weak roving strength.
The operation content may be changed according to the yarn type, such as providing slack in roving such as synthetic fiber having a relatively long fiber length and high roving strength.

(6) The number of reverse rotations of the flyer 4 at the time of returning the strong twist does not necessarily have to match the number of revolutions of the flyer at the time of strong twist. For example, the number of reverse rotations of the flyer 4 may be set to be smaller than the number of rotations of the flyer during strong twisting, in consideration of the fact that the twist naturally returns from the cut end that is the free end when the roving is cut. Further, the rotation speed of the flyer 4 can also be changed as appropriate, and for example, the rotation speed of the flyer 4 may be different during strong twisting and untwisting.

(7) The feed length of the roving R after the strong twist is not limited to the length until the strong twist reaches before the presser arm 30b, and the portion where the roving R is easily cut is strong. The twisted state can be set appropriately. Further, it is not always necessary to feed the roving R after the strong twist.

(8) The reverse operation of the flyer 4 for returning the twist of the strongly twisted portion can be changed at an appropriate time after the roving is cut and before the next winding of the roving on the bobbin B is started. For example, the flyer 4 may be started to rotate in the reverse direction while the bobbin rail is descending after the roving is cut.

(9) A clutch may be arranged between the flyer drive system and the spindle drive system to stop the bobbin B when the flyer rotates in the reverse direction. (10) Control signals KS, MS, WS, LS, etc. are sent to the CPU 3
Instead of being output from 3, the control signals KS, MS, WS, LS and the like may be output to each drive circuit by on / off control by a switching circuit.

(11) The flyer 4 may be provided with an operation button and the like for reverse operation, and the flyer 4 may be operated in reverse when the operation button is pressed.

[0044]

As described in detail above, according to the present invention, the roving yarn is strongly twisted at the time of doffing and cut at an appropriate position, and then the flyer is reversed in the direction of returning the twist of the strongly twisted roving yarn. Because of the configuration, even if the roving yarn is twisted strongly before cutting the roving yarn at the time of doffing, the number of twists at the beginning of winding on the next bobbin can be made to be about the same as at the time of normal spinning. It has an excellent effect that the roving wound on the reel can be used up to the end.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a procedure for cutting a roving yarn in an embodiment embodying the present invention.

FIG. 2 is a schematic side view of the same.

FIG. 3 is a schematic side view of the same.

FIG. 4 is a schematic diagram of a drive system of a roving frame.

FIG. 5 is a block diagram showing an electrical configuration of a control device.

FIG. 6 is a time chart of each control signal output from the CPU.

[Description of Reference Signs] 1 ... Front roller, 4 ... Flyer, 4a ... Flyer top, 8 ... Bobbin rail, 9 ... Spindle, 13 ... Winding motor that constitutes spindle drive means, 14 ... Difference that constitutes spindle drive means Dynamic gear mechanism, 19 ... Switching mechanism that constitutes bobbin rail driving means, 20 ... Lifting motor that constitutes bobbin rail driving means, 27 ... Electromagnetic clutch as switching means, 30 ... Presser, 30a ... Presser battledore, 31 ... Drive A control device as control means, M ... a main motor that constitutes a spindle drive means and a main drive means,
B ... bobbin, R ... roving.

Claims (3)

[Claims] 1. A coarse thread for descending a bobbin rail in a state where a roving thread extending from a front roller to a flyer is twisted more strongly than a normal spinning operation at the time of doffing and cutting the roving thread in the vicinity of exiting a battlement plate of a presser. In the method for cutting the roving unwinding tail at the time of doffing in a spinning machine, after cutting the roving, the flyer is rotated by a predetermined amount in the direction to return the strong twist hung on the roving Method. 2. The bobbin is rotated at the same rotational speed as the flyer for a short time after stopping the machine for doffing or immediately before stopping the machine, with the roving from the front roller stopped. The operation of giving the roving thread stretched between the flyer top and the roving thread a stronger twist than the twist given to the roving thread during normal spinning, and the roving portion for sending out the strongly twisted portion between the front roller and the flyer top. After performing the operation of winding the thread and the operation of providing a predetermined slack in the roving thread stretched between the front roller and the flyer top, lower the bobbin rail to the predetermined position for doffing. Cutting the roving yarn near the exit of the presser's battledore, and after cutting the roving yarn, rotate the flyer by a predetermined amount in the direction to return the strong twist given to the roving yarn. Method. 3. A main driving means for driving the front roller and the flyer at a predetermined rotation ratio and at least driving the flyer so that the flyer can rotate forward and backward, and a connection state for operatively connecting the front roller and the main driving means. Switching means capable of switching to a disconnecting state for disconnecting the operational connection between the front roller and the main drive means, a non-winding state in which the spindle can be rotated in the same direction as the flyer at the same speed, and a spindle in the flyer A spindle driving means that can be driven into a winding state in which the bobbin rail can be rotated in the same direction at a higher winding speed than the flyer; a bobbin rail driving means that lowers the bobbin rail from a full pipe stop position to a doffing position; A coarse unit including a drive unit, the switching unit, the spindle drive unit, and a control device that drives and controls the bobbin rail drive unit. Crude yarn butt cutting device during doffing in the machine.