JPH09227023A - Control method for hip wound length in spinning machine and device thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the dispersion of hip wound yarn length and easily change the length. SOLUTION: The spinning quantity LS during the deceleration time set in advance until a ring fine spinning machine is stopped after it becomes full is determined from the spinning speed at that time, the deceleration start timing Md is calculated as the rotation position of a heart cam based on it, and the machine is inverter-decelerated at this timing to be stopped. When the total length of the barrel wound length obtained in advance and the set hip wound length is spun out, the timing when the valley section of the heart cam appears is calculated back, a ring reel is automatically lowered at this timing during the inverter deceleration process, and the hip winding of the set length is applied.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a ring spinning machine,
In a spinning machine such as a ring twisting machine, the present invention relates to a technique for automatically lowering a ring rail to wind a tail around a lower portion of a spindle or a tubular yarn when a full pipe is stopped, and particularly to a technique for controlling a tail winding length.

[0002]

2. Description of the Related Art In a ring spinning machine, a chase and a shaper feed are given to a ring rail and gradually raised to wind a thread around an empty bobbin to form a predetermined thread, and when the thread is full, the thread is wound. The ring rail located at the upper part is separated from the shaper feeding mechanism and automatically lowered to wind the bobbin around the bobbin or the bottom part of the bobbin or the spindle. This tail winding is necessary in order to hold the yarn at the beginning of winding on the empty bobbin at the time of restarting after the doffing of the full pipe yarn, but if the length is short, the yarn holding will not work well, Further, when the length is too long, excess waste yarn is generated, and therefore it is preferable that the tail winding yarn having a predetermined length is formed. Therefore, conventionally, the main motor of the spinning machine is turned off by inertial rotation. Then, the ring rail is automatically lowered during its inertial rotation, and the timer is activated from the time when the ring rail is lowered to the tail winding position of the lower part of the spindle. The main motor of the spinning machine is braked due to time-up to reduce the variation in the number of tail windings regardless of the machine condition (Japanese Patent Publication No. 7-56091).
No.) is known.

[0003]

In the above technique, the number of times the tail winding is wound (tail winding length) is determined by the time after the ring rail reaches the tail winding position. When trying to adjust the optimum value for frying motion, it is necessary to convert "length" and "time", and the operator cannot directly set "length". Is difficult to understand and there is a problem that it is not easy to use. Further, in the above technique, the brake is forcibly braked after a predetermined time has passed at the tail winding position, and the traveler guiding the yarn on the ring rail at the time of the forcible braking is as indicated by the chain double-dashed line X in FIG. Due to its own inertia, it cannot be stopped synchronously with the spindle (tubular thread) and rotates excessively, and as a result, the thread clings to the outer circumference of the full thread, and when the full thread is pulled out at the time of doffing, the thread clung There was also the problem of being pulled and causing thread breakage. A first object of the present application is to provide a technique for making the length of the tail winding thread constant, and to provide a tail winding length control technology capable of directly giving the "length" itself when changing the length. It is in. In addition to the first problem, the second problem is to provide a technique for controlling the tail length that does not involve forced braking by a brake and, as a result, allows the traveler to stop synchronizing.

[0004]

[Means for Solving the Problems] To solve the first problem,
In the present application, the tail winding length is given in advance, and the sum of the tail winding length and the body winding length when the ring rail is descending is back-calculated for the timing at which the spinning yarn length is reached until the machine is completely stopped after the pipe is fully loaded. Make the ring rail automatically descend at the timing. When changing the tail length, the timing is calculated back by changing the “tail length” itself, so there is no need for conversion as in the conventional case. To solve the second problem, the ring rail is automatically lowered at the above timing in the process of performing speed control for stopping the machine base by deceleration control by the inverter after the pipe is full.
Since the deceleration control by the inverter leads to the stop, the traveler can stop synchronously with the spindle without requiring the forced braking by the brake.

[0005]

According to a first aspect of the present invention, there is provided a method for controlling a tail winding length in a ring spinning machine, a ring twisting machine, etc., which comprises a body winding length and a preset tail winding length, and spinning per unit rotation of a heart cam. Based on the length of the roll, the ring rail descent start time, which is the valley of the heart cam when the total length of the body length and the tail length is spun, is calculated, and the rotation of the heart cam after full pipe is detected. , The ring rail starts to descend when it reaches the rotation position of the heart cam that corresponds to the start time of the ring rail descent starting from the valley of the heart cam, and stops the machine when the next valley of the heart cam arrives. I chose The body roll length corresponds to the spinning length of the front roller while the ring rail is descending when the ring rail is automatically descended by the entire ascent movement of the ring rail fed by the shaper. From the sum of the rotation speed ratio of the drive system from the front roller to the lifting drum and the total feed amount of the shaper until the automatic descent is started (the length is the lift amount minus the chase amount when full). It is something that can be uniquely determined for a stand.

The lowering of the ring rail is performed in the process of deceleration control in which the machine base is stopped by the inverter after the pipe is full. The deceleration control is carried out from the spinning rotation level after the pipe is fully loaded, and the spinning amount per unit rotation of the heart cam and the spinning amount in the deceleration section when the main motor is inverter-controlled at a preset deceleration gradient toward the machine stop. The deceleration start time is calculated based on the output amount, the rotation of the heart cam after full filling is detected, and when the heart cam rotation position corresponding to the deceleration start time starts from the valley of the heart cam The motor is started to decelerate by the inverter, and the main motor is guided to the stop at the deceleration gradient, so that the machine base is stopped when the next valley of the heart cam arrives.

In the above-mentioned method, the heart cam rotational position detecting means is connected to the heart cam, the heart cam rotational position detecting means and the control means are connected, and the control means is preset with the body winding length obtained as described above. Based on the tail roll length and the spinning amount per unit rotation of the heart cam, the descent start time calculation means for calculating the rotation position of the heart cam corresponding to the ring rail descent start time starting from the valley of the heart cam, and a full pipe Output means for outputting a ring rail automatic lowering signal to the ring rail automatic lowering device when the heart cam rotational position later detected by the heart cam rotational position detecting means becomes a rotational position corresponding to the ring rail lowering start time,
And a stopping means for stopping the machine base when the heart cam reaches the next trough.

Further, the stopping means is means for obtaining a spinning amount in a deceleration section when the main motor is inverter-controlled by a preset deceleration gradient from the spinning speed level after full pipe to the machine stand stop, A means for calculating the deceleration start time based on the spinning amount and the spinning amount per unit rotation of the heart cam, and the heart cam rotation position detected by the heart cam rotation position detection means after full filling is starting from the valley of the heart cam. And output means for starting deceleration of the main motor by an inverter when the rotational position corresponding to the deceleration start time is reached, and by guiding the main motor to stop at the deceleration gradient, the next valley of the heart cam arrives. It is configured to stop the machine when it does.

More specifically, the heart cam rotational position detecting means is a pulse generator, and the control means includes a calculating means for calculating a spinning amount corresponding to one pulse of the pulse generator, and a pulse generating means. A pulse counter that counts the pulses from the device starting from the valley and resets the count value with one rotation of the heart cam, and a pulse that indicates the heart cam rotation position that corresponds to the count value, deceleration start position, and ring rail descent start position. And a comparison means for comparing with the number.

[0010]

1 is a spindle of a spinning machine, which is rotated from a main motor 2 via a chin pulley shaft 3 and the like. The main motor 2 drives the front roller 5, the middle roller 6, and the back roller 7 of the draft part 4 so as to have a predetermined draft ratio. As shown in FIG. 6, the traveler 8 is rotatably supported on the ring rail 10, and the yarn Y spun from the front roller 5 is wound around the bobbin B via the snare wire 9 and the traveler 8 through the traveler 8. Has become.

The ring rail 10 is a lifting pillar 1.
1, the lower end of the lifting pillar 11 is connected to one end of the lifting tape 12. The other end of the lifting tape 12 is connected to a lifting roller 14 integrally attached to the ring rail lifting shaft 13. Another roller 15 is attached to the ring rail lifting shaft 13.
Is integrally attached, and the other end of the lifting tape 16 having one end fixed to the roller 15 is fixed to the lifting drum 19 via a guide roller 18 which is rotatable in the middle of the lifting lever 17.

The lifting lever 17 is swingably supported around a pivot 20 which is integral with the lifting drum 19. The tip of the lifting lever 17 is pressed against the heart cam 21. The heart cam 21 includes a pulley 22, a chain 23, a pair of gears 25, a heart cam 21 from the front roller 5.
It is adapted to be rotated via a drive system composed of a heart cam shaft 21A integrated with the above. By swinging the lifting lever 17 while the heart cam 21 makes one rotation, the pawl feed wheel (ratchet wheel) 2 of the shaper feed mechanism 24 is moved.
6 is sent one by one, and this rotation is transmitted through the clutch 27, the gear pair 28 and the pivot 20 to the lifting drum 19
Is rotated in the tape winding direction, which gives shaper feed in which the ring rail 10 gradually rises.
The valley 21a of the heart cam 21 is the lifting lever 17
By making one rotation from the position where it is pressed against the tip, the ring rail 10 is given one cycle of vertical movement (chase) via the guide roller 18. The clutch 27 is engaged only while the thread is being formed, and is disengaged when the machine stand is stopped when the thread is full. Another clutch 62 is interposed in the drive system between the gear pair 28 and the pulley 22, and the clutch 62 is engaged only when the clutch 27 is disengaged, that is, when the machine is stopped when the pipe is full, and thus the clutch 62 is engaged. In the state where 62 is connected, the shaper is not fed, and the ring rail 10 is rotated at the tail winding position S (FIG. 6) at a predetermined descending pitch depending on the rotation speed ratio determined by the drive system from the front roller 5 to the lifting drum 19. A ring rail automatic lowering device 40 that automatically lowers to is configured.

The main motor 2 is an induction electric motor whose drive is controlled via a general-purpose inverter INV which is a variable frequency power supply device. The frequency setting terminal a1 of the inverter INV is connected to each of the switches S1 to S3 and the speed setting resistor r1.
Speed setting circuits 30 to 32 in which .about.r3 are connected in series are connected in parallel. Also, the acceleration gradient setting terminal a2 and the common terminal a
An acceleration gradient setting circuit 33 in which a contact point R1a of an acceleration relay R1 and an acceleration gradient setting resistor VR1 are connected in series is connected between the four. Between the deceleration gradient setting terminal a3 and the common terminal a4, there is connected a deceleration gradient setting circuit 34 in which a resistor VR2 for setting the deceleration gradient at the time of full pipe stop and a contact R2a of the deceleration relay R2 are connected in series.

The resistor VR2 of the deceleration gradient setting circuit 34 is
As shown in FIG. 4, the resistance value is set so as to realize the deceleration gradient DEC that leads to the stop of the machine base without braking from the high speed spinning rotation state (spindle rotation speed V3),
This deceleration gradient DEC is determined in advance by trial spinning so that an appropriate amount of snare 29 is formed as shown in FIG. 6 when the inverter deceleration is started and stopped by the deceleration start signal described later after the full pipe signal. There is. The snare 29 is set to an amount that is stretched when the empty tube is inserted in the tube replacement operation.

A control means 50 is connected to the inverter INV. An acceleration relay R1 and a deceleration relay R2 are connected to the control means 50, and a spinning length from a spinning length measuring pulse generator 54 that detects the rotation of the front roller 5 and generates a pulse for each unit rotation. Data, heart cam 2
1, which is integrally connected to the heart cam shaft 21A that is integral with 1, and generates a pulse for each unit rotation of the heart cam 21 (here, 160 pulses are generated for one rotation of the heart cam 21). Each pulse generator 54, 55 is also connected so that heart cam rotational position data from another pulse generator 55 is input. An input device 53 is connected to the control means 50,
From this input device 53, the data necessary for the calculation of the start time of the ring rail descent (data for the calculation of the body roll length LD (chase H, lift L (this lift length is the total lift length when the pipe is full), the front roller 5) To clutch 62, gear pair 2
The body winding coefficient K determined by the rotation ratio of the drive system reaching the lifting drum 19 via 8 and the required tail winding length L
B), and the time Tdec required for deceleration when performing deceleration control from the steady high speed rotation (rotational speed FV3) to the machine stand stop at the speed gradient DEC, the full pipe length, etc. are input. Also,
The control means 50 integrates the pulses from the pulse generator 54 to obtain a spinning amount from the beginning of winding, and a pulse counter 61 that integrates the pulses from the pulse generator 55. The pulse counter 61 is reset by one rotation (160 pulses) from the trough 21a of the heart cam 21 to the next trough 21a, and the count value is the trough 21a (rotation of the heart cam 21). The rotation position from the origin is shown.

The control means 50 stores an operation control program according to the flow chart shown in FIG. 3 in advance.
Each control step in this flowchart constitutes a function realizing means. That is, step S1 is a data setting means, step S2 is a machine rotation control means up to full pipe, and controls the switches S1 to S3 and the acceleration relay R1 as shown in FIG. Control the rotation of the machine base (until the start time). Step S3 is the heart cam shaft 21.
A spinning amount calculation unit per pulse (unit rotation) of A, step S4 determines the rotation position of the heart cam 21 at the start time of the ring rail descent based on the body roll length LD when the ring rail is descending and the tail roll length LB which is set in advance. The ring rail descent start timing calculating means, which is obtained by the number of pulses Ld shown, is a step S5 which determines whether or not the pulse count value of the pulse counter 60 has reached the number of pulses corresponding to a preset full pipe length from the start of winding. Pipe discriminating means, step S6 is a means for calculating the spinning amount when the vehicle is decelerated and stopped by inverter control in the deceleration section (FIG. 4), and step S7 is the spinning amount in the deceleration section per pulse of the heart cam shaft 21A. A calculation means for dividing the spinning amount by the pulse number Md indicating the rotational position of the heart cam 21 to determine the deceleration start time, the step S8 is counting by the pulse counter 61. Is a means for comparing whether the number of pulses Md corresponding to the deceleration start time coincides, a step S9 is a deceleration start command means for outputting an excitation signal of the deceleration relay R2 when the same is coincident in step S8, and a step S10 is a pulse counter. Means for comparing whether the count value of 61 matches the pulse number Ld corresponding to the start time of the ring rail descent,
Step S11 is a means for outputting a ring rail automatic lowering command that outputs a disconnection signal to the clutch 27 and a connection signal to the clutch 62 to cause the ring rail 21 to automatically lower when the coincidence is obtained in step S10.

Next, the operation will be described. Prior to the machine operation, the lift L, the chase H, the body winding coefficient K, the deceleration time Tdec, and the full pipe length are input from the input device 53 and stored in the control means 50 in step S1. Then, when the machine base is started, the inverter 20 is started in step S2, the acceleration relay R1 of the control means 50 is excited, the contact R1a of the acceleration gradient setting circuit 33 is closed, and the switch S1 is closed. As shown in 4, the spindle rotation is increased to the rotation speed V1. Next, the switches S2 and S3 are sequentially closed according to the winding amount, and the spindle rotation speed reaches the maximum spinning rotation of the rotation speed V3 via the rotation speed V2. When the spindle 1 rotates, the yarn Y is wound around the bobbin B via the traveler. The ring rail 10 moves from the winding start position corresponding to the lower end of the bobbin B to the lifting lever 17 by rotating the heart cam 21.
While the chase is repeated by the rocking of, the shaper feed is given and gradually rises toward the full pipe to form the yarn.

Thus, the spinning operation is continued at the rotation speed V3, and step S3 is executed until the winding amount becomes full. In step S3, the spinning amount L spun by a predetermined rotation of the front roller 5 (for example, 30 pulses of the pulse detector 54).
Since L is known in advance, the heart cam shaft 21A is calculated by the following formula.
The spinning amount LYP per pulse of is calculated. LYP = LL / PF (PF is the number of pulses of the heart cam 21 when spinning by the predetermined spinning amount LL, and is a value obtained by counting the pulses from the pulse generator 55) Next, in step S4, the ring is calculated by the following equation. Rail 10
The descent start time is calculated as the pulse number Ld indicating the rotational position starting from the valley 21a of the heart cam 21. Ld = number of pulses generated in one rotation of the heart cam in the pulse generator (160 pulses)-(body roll length LD + tail roll length LB) / L
YP However, the body length LD is the spinning amount obtained from the rotation of the front roller 5 when the front roller 5 is automatically lowered by the height of the ring rail raised by the shaper feed when the body is wound up to the full pipe. LD = body roll coefficient K × (L (lift) −H (chase)), which is calculated by how much the front roller 5 rotates while the ring rail 10 automatically descends by (L−H). Or a constant determined from the rotation speed ratio of the drive system from the front roller 5 to the lifting drum 19 via the clutch 62. Needless to say, when the winding amount before the full pipe is considered to be a full pipe, for example, the lift L is the lift amount at the time of winding the seven-minute pipe.

Next, in step S5, it is judged whether the integrated value of the number of pulses from the pulse generator 54 has reached a value indicating a full pipe length, and if the pipe is full, in step S6 the machine is stopped from the speed at that time. The spinning amount LS when the vehicle is decelerated with the deceleration gradient DEC toward the position is calculated by the following formula. LS = SD × Tdec / 2, where SD is the spinning speed at that time calculated from the time when the pulse generator 54 generates a predetermined number of pulses, Tdec
Is the deceleration time (described above). In the present embodiment, the inverter deceleration starts immediately from the high speed (rotation speed V3). However, for example, the speed is reduced from the high speed (rotation speed V3: a preset constant) to the low speed (rotation speed F) before deceleration. When entering the inverter deceleration, the above equation is as follows. LS = SD × F × Tdec / (2 × V3) Next, in step S7, the number of pulses M indicating the rotational position from the valley of the heart cam 21 as the starting point for the deceleration start time according to the following equation.
Calculate as d. Md = number of pulses generated by the pulse generator for one rotation of the heart cam (160 pulses) -LS / LYP

Next, in step S8, the valley portion of the heart cam 21 that first arrives after the full pipe (starting point of pulse count)
21a, the pulse from the pulse generator 55 is counted by the pulse counter 61, and when the count value matches the pulse number Md indicating the deceleration start time, the deceleration relay R2 is turned on (deceleration start signal) in step S9 to set the deceleration gradient. The setting circuit 34 is turned on, and the spindle rotation is gradually decreased toward the stop at the deceleration gradient DEC. In the deceleration process,
In step S10, when the count value of the pulse counter 61 coincides with the pulse number Ld indicating the ring rail descent start time, a ring rail automatic descent signal is output, the clutch 27 is disengaged to stop the shaper feed, and the clutch 62 is replaced. By connecting and rotating the lifting drum 19 in reverse at a predetermined rotation ratio with respect to the rotation of the front roller 5, the ring rail 10 is lowered, and the body winding coefficient K determined by the drive system of the machine base is set. A body winding Fa having a body winding length LD determined by the lift L and chase H is performed around the outer circumference of the full tube F, and the ring rail 10 descends to a tail winding position S facing the lower end of the bobbin, and at that position, the tail winding thread Fb. Is wound on the lower end of the bobbin by the tail winding length LB set by. At the timing when the tail winding length LB is completed, one rotation of the heart cam 21 is completed and the valley portion 21a of the heart cam 21 is brought into a position to engage with the swing lever 17, and at that time, the spindle 1 is just stopped.

Since the spindle rotation is guided to the stop by the deceleration control of the inverter INV in this manner, it is not necessary to forcibly brake the inertia rotation as in the conventional case when the spindle is stopped. Therefore, the traveler 8 rotates by inertia. It never passes. Therefore, the yarn does not cling to the outer circumference of the full yarn, and the yarn does not break during doffing. In addition, based on the body roll length and the tail roll length of the ring rail descent time, when the total length of these is spun, the time just to be the valley of the heart cam 21 is calculated backward, and the ring rail descent is performed at that timing. Since it has started, the bobbin length and the tail winding length are surely guaranteed, and the tail winding length does not vary from the planned length.

[0022]

As described above, according to the present invention, the time required to spin out the total length of the trunk length and the tail length is reversely calculated in advance, and the ring rail is lowered when the time is reached. Since it is stopped at the valley of the heart cam, a preset tail roll length is guaranteed, and when changing the tail roll length, the tail roll length can be changed directly. There is no time conversion, and the change operation is easy. Further, the timing for starting deceleration by the inverter is calculated back based on the spinning amount in the deceleration section from the predetermined deceleration gradient to the stop, and the deceleration starts at that timing. Becomes zero,
Since there is no need for forcible braking, the traveler can also stop synchronously with the yarn, and can prevent over-turning due to the inertia of the traveler compared to the one that was conventionally accompanied by braking, and the yarn can be clung to the yarn. It can prevent thread breakage when fried.

[Brief description of drawings]

FIG. 1 is a diagram showing an entire drive system of a ring spinning machine for carrying out the present invention.

FIG. 2 is a diagram showing a control means.

FIG. 3 is a diagram showing a control flowchart.

FIG. 4 is a diagram showing an operation pattern (spindle rotation shift pattern) of the machine base.

FIG. 5 is a diagram showing a spindle shift state at the time of stop and a ring rail up / down state according to the present invention.

FIG. 6 is a diagram showing a tubing in a fully-filled state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spindle 2 Main motor 5 Front roller 10 Ring rail 21 Heart cam 21a Heart cam valley 24 Shaper feeding mechanism 26 Claw feeding wheel 27 Clutch 50 Control means 53 Input device 55 Pulse generator 61 Pulse counter 62 Clutch INV General-purpose inverter

Claims (6)

[Claims] 1. A method for controlling a tail winding length in a ring spinning machine, a ring twisting machine, or the like, which is based on a body winding length, a preset tail winding length, and a spinning length per unit rotation of a heart cam. When the total length of the body roll length and the tail roll length is spun, the ring rail descent start time, which will be the valley of the heart cam, will be obtained, the rotation of the heart cam after full filling is detected, and the valley of the heart cam is started. As the bottom of the spinning machine characterized by starting the descent of the ring rail when it reaches the rotation position of the heart cam corresponding to the ring rail descent start time and stopping the machine base when the next valley of the heart cam comes Winding length control method. 2. A method for controlling a tail winding length in a ring spinning machine, a ring twisting machine, etc., which is based on a body winding length, a preset tail winding length, and a spinning length per unit rotation of a heart cam. , When the total length of the body roll length and the tail roll length is spun, the ring rail descent start time, which is the valley of the heart cam, is obtained, and after the full pipe, the inverter stops rotation of the spinning frame. When the rotation is detected and the valley of the heart cam is the starting point, the ring rail starts descending when it reaches the rotation position of the heart cam that corresponds to the ring rail descent start time, and when the valley of the next heart cam arrives. A method for controlling the tail length in a spinning machine, which comprises stopping the machine base. 3. The spinning amount per unit rotation of the heart cam and the spinning amount in the deceleration section when the main motor is controlled by the inverter with a preset deceleration gradient from the spinning rotation level after the full pipe to the machine stop. The deceleration start time is calculated based on the output amount, the rotation of the heart cam after full filling is detected, and when the heart cam rotation position corresponding to the deceleration start time starts from the valley of the heart cam 3. The motor is started to decelerate by an inverter, and the main motor is guided to stop at the deceleration gradient so that the machine base is stopped when the next valley of the heart cam arrives. Control method of tail roll length in spinning machine. 4. In a spinning machine, such as a ring spinning machine and a ring twisting machine, in which a ring rail is automatically lowered by a ring rail automatic lowering device to form a tail winding after full filling, a heart cam rotational position detecting means is provided on a heart cam. Connect the heart cam rotation position detection means and the control means, and the control means determines the body roll length determined based on the height position of the ring rail at the start of descent, the tail roll length set in advance, and the unit rotation of the heart cam. Based on the spinning amount per hit, it corresponds to the ring rail descent start time starting from the valley of the heart cam, which is just the valley of the heart cam when the total length of the body length and the tail length is spun. The ring rail descends when the descent start timing calculation means that calculates the rotation position of the heart cam and the heart cam rotation position detected by the heart cam rotation position detection means after full filling Output means that outputs the ring rail automatic descent signal to the ring rail automatic descent device when the rotation position corresponding to the starting machine is reached, and stop means that stops the machine base when the heart cam reaches the next trough. A tail winding length control device for a spinning machine, comprising: 5. The stop means is a means for obtaining a spinning amount in a deceleration section when the main motor is inverter-controlled with a preset deceleration gradient from the spinning rotation level after full pipe to the machine stop. , The means for calculating the deceleration start time based on the spinning amount and the spinning amount per unit rotation of the heart cam, and the heart cam rotation position detected by the heart cam rotation position detection means after full filling is the valley portion of the heart cam. An output means for starting deceleration of the main motor by an inverter when the rotational position corresponding to the deceleration start time is set as a starting point, and by guiding the main motor to a stop at the deceleration gradient, the valley portion of the next heart cam is 5. The tail winding length control device for a spinning machine according to claim 4, wherein the machine base is stopped when the machine arrives. 6. The heart cam rotational position detecting means is a pulse generator, and the control means includes a calculating means for calculating a spinning amount corresponding to one pulse of the pulse generator, and the pulse from the pulse generator is reduced. Comparison that compares the pulse counter that resets the count value with one rotation of the heart cam by counting from the section as the starting point and the count value and the pulse number indicating the heart cam rotation position corresponding to the deceleration start position and ring rail descent start position 6. A tail winding length control device for a spinning machine according to claim 5, further comprising: