JPH06200453A - Tension control of flat knitting machine - Google Patents

Abstract

PURPOSE:To enable control of the stitch density to a constant value and to enable reproduction of the optimum touch by detecting the amount of a fed yarn corresponding to the tension of the fed yarn and controlling the tension of the fed yarn in a flat knitting machine. CONSTITUTION:In a knitting machine in which the tension of a fed yarn is controlled corresponding to a calculated deviation value between the target yarn length and the actually consumed yarn length, the optimally set tension value and the corresponding standard yarn length shown in case the tension is set in a trial knitting so as to optimize the stitch density and the touch of an actual knitted fabric corresponding to a knitting pattern are memorized. In an actual knitting, the set tension and the target yarn length are changed respectively to the optimum tension value and the optimum standard yarn length corresponding to a knitting pattern in that knitting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a yarn feeding tension in a flat knitting machine.

[0002]

2. Description of the Related Art In Japanese Patent Publication No. 1-49816, in order to make the stitches constant, a deviation between a target yarn length calculated and the yarn length actually consumed is obtained, and the deviation is calculated according to this deviation. A method of controlling yarn tension is disclosed. Here, the target yarn length is determined corresponding to the knitting pattern.

According to the above technique, since the target yarn length is a theoretical value calculated, it may be possible to obtain the degree of the theoretical value as a result of the control at the actual knitting stage, but the texture at that time. Is not guaranteed.

Japanese Patent Laid-Open No. 59-106548 discloses that
In order to keep the stitches constant, the length of the knitting yarn actually knitted between the specific needles of the reference course is set as the target yarn length, and the deviation between this target yarn length and the actually consumed yarn length is obtained,
It is disclosed that a knitting cam that changes the degree according to the deviation is controlled. According to this control, there is no specific description of how the tension is set when determining the target yarn length.

On the other hand, in the case of a flat knitting machine, since the yarn feeding speed changes abruptly depending on the knitting pattern, it is difficult to detect the tension of the knitting yarn and control the tension of the knitting yarn to be constant. Therefore, tension control is performed by detecting another parameter in place of tension.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to, in a flat knitting machine, respond to the yarn feeding tension, detect the yarn feeding amount, control the yarn feeding tension, keep the stitches constant, and reproduce the optimum texture. To do so.

[0007]

According to the first aspect of the present invention, based on the above object, the yarn length when the tension is set so that the stitch size and the texture of the actual knitted fabric in the trial knitting is optimized is targeted. The yarn length is stored as a yarn length, the deviation between the target yarn length and the actually consumed yarn length is obtained in main knitting, and the yarn feeding tension is controlled according to the deviation. Also,
According to claim 2, the optimum set tension corresponding to the knitting pattern in the trial knitting and the reference yarn length at that time are stored, and in the main knitting, the set tension and the target yarn length are optimized corresponding to the knitting pattern at that time. The tension value and the standard thread length are changed.

According to the control corresponding to the above claim 1, the target yarn length is the yarn length at which the optimum stitch and the optimum texture are actually obtained in the trial knitting. And the optimum texture can be reproduced. Further, according to the control according to claim 2, the optimum set tension corresponding to the actual knitting pattern can be changed, so that the changed set tension has a close value in order to obtain the optimum stitch and texture. . Therefore,
Since the tension correction amount can be minimized, stable control can be realized.

[0009]

1 shows the construction of a tension control system according to the present invention. The knitting yarn 1 is unwound from the yarn supplying package 2, passes through a yarn guide 6, and between a pair of rollers 4 and 5 as a tension control means 3, and a predetermined tension is applied to a yarn feeder 7 by a rotational torque of these rollers. Supplied, where needle bed 8
Are guided to the positions of a plurality of knitting needles 9 provided along the.

The pair of rollers 4, 5 sandwich the knitting yarn 1 between them in order to apply a predetermined tension to the knitting yarn 1 by the rotating torque, and one of the rollers 4, 5 is
The driving side is driven by the motor 10 for controlling the rotational torque, and the other side is the driven side, which is driven by being brought into contact with the driving side roller 4.

The rotational torque as the output of the motor 10 is
.. 1n, the output of which is an input signal to the current amplifier 15 via the switch 13 and the comparison point 14. The current amplifier 15 applies a current according to the target tension given by the tension setters 11, 12, ..., 1n to the motor 10 to rotate the torque acting between the pair of rollers 4, 5, that is, for the knitting yarn 1. Control the tension. The output current of the current amplifier 15 is detected by the current detector 16 and sent to the comparison point 14 as a current feedback signal.

On the other hand, the rotation amount of the drive side roller 4 is detected by the rotation detector 17 by the pulse number, and is measured as the yarn length L of the knitting yarn 1 by the yarn length measuring device 18.
The yarn length measuring device 18 inputs a measurement start signal and a measurement end signal at the start point and the end point of a predetermined section in which the yarn feeder 7 runs, and measures the yarn length L of the knitting yarn 1 during this period. Then, the measured yarn length L is input to the storage device 20 in addition to the comparator 19. Knitting pattern memory 21
Is the measured yarn length L based on the reference yarn lengths L1, L2, ... Ln
In order to store together with the knitting patterns P1, P2, ... Pn, the knitting patterns are connected to the storage device 20 and also to the knitting control device 22. The knitting pattern is a signal for discriminating a difference in knitting structure such as a plain knitting and a rubber knitting, a difference in size of the stitches in the same knitting structure, or a difference for each course.

The comparator 19 is for obtaining the deviation ΔL of the yarn length during the actual knitting, that is, during the main knitting, and sends the deviation ΔL to the comparison point 14 via the manual changeover switch 23. The storage device 20 is connected to the switching device 13 and has knitting patterns P1 and P.
Based on Pn, tension setters 11, 12, ...
Switch 1n. The knitting control device 22 controls the operations of the yarn feeder 7 and the knitting needles 9 based on the knitting patterns P1, P2, ... Pn to control the necessary knitting operation of the knitting machine.

At the stage of trial knitting of a certain knit, the operator sets the manual changeover switch 23 to the contact 23 for main knitting.
1 is switched to the contact 232 for trial knitting, the switching device 13 is manually switched, and the tension setting devices 11, 1
2 ... 1n is selected, and the tension setter is operated to set the drive current of the motor 10 so that the optimum stitches, that is, the optimum stitches and textures are obtained. The rotational torque of 5, that is, the tension of the knitting yarn 1 corresponding thereto is set.

At the trial knitting stage, when the optimum stitch is obtained, the yarn length measuring device 18 is started in a predetermined section, for example, one course, and is finished after the one course is finished. Measure L and store it in memory 2
Send to 0. Here, the storage device 20 stores the measured yarn length L corresponding to the knitting pattern P1 at the time of measurement as the reference yarn length L1.
And the switching code 11 corresponding to the selected tension setting device 11 is stored. Hereinafter, by repeating the same operation for all knitting patterns P2, P3, ... Pn, as shown in FIG. 2, the reference yarn lengths L1, L2, ... For the knitting patterns P1, P2 ,. L
n and the tension setting devices 11, 12, ... 1n are stored while being associated with the switching codes 11, 12 ,.

In the subsequent actual knitting process, that is, the main knitting process, the manual changeover switch 23 is switched from the contact 232 for trial knitting to the contact 232 for main knitting. In the main knitting process, the knitting pattern storage device 21 outputs the knitting pattern Pi at that time to the storage device 20. Therefore, the storage device 20 outputs the switching code 1i of the tension setting device 1i corresponding to the knitting pattern Pi to the switching device 13 based on the stored contents, and the switching device 13 operates the tension setting device 1i corresponding to the switching code 1i. Select. Further, the reference yarn length Li corresponding to the knitting pattern Pi is given to the comparator 19 as the target yarn length.

As described above, the storage device 20 and the knitting pattern storage device 21 cause the switching device 13 to perform the switching operation, and the signal for tension setting of the tension setting device 1i corresponding to the knitting pattern Pi is input to the current amplifier 15. By doing so, the motor 10 is rotated with a required rotation torque. As a result, the required rotational torque is applied to the pair of rollers 4 and 5 to set the tension of the knitting yarn 1 to the target tension value.

In this continuous knitting process, a predetermined cycle, for example, 1
The actual yarn length L is measured by the yarn length measuring device 18 for each course and input to the comparator 19. Here, the comparator 1
9 compares the target yarn length corresponding to the current knitting pattern Pi, that is, the reference yarn length Li with the yarn length L measured in the main knitting process, and sends the deviation ΔL to the comparison point 14 as a signal for tension correction. In this way, the control system for the tension control means 3 changes the target tension based on the knitting patterns P1, P2, ... Pn and the reference yarn lengths L1, L2 ,. By setting an appropriate tension on the knitting yarn 1, the actually used yarn length L is actually measured, and the yarn length based on the deviation ΔL from the reference yarn length Li is controlled as a correction amount.

Thus, the actual knitting patterns P1 and P
Since the setting tension is changed to the optimum setting tension corresponding to 2, ... Pn, the changed setting tension is an approximate value in order to obtain the optimum degree and texture. Therefore, the tension correction amount can be minimized and stable control can be realized. As described above, the trial stitch knitting provides the optimum stitch and texture, and based on this, the optimum stitch and texture can be reproduced in the main knitting process.

FIG. 3 shows another example of tension setting.
An appropriate tension signal T is set by one tension setting device 11 at the trial knitting stage. This tension signal T is stored in the storage device 20 as the knitting pattern Pi from the knitting pattern storage device 21.
Will be remembered along with. Therefore, in this example,
As shown in FIG. 4, the reference yarn length Li and the set tension Ti are stored in the storage device 20 in correspondence with the knitting pattern Pi. At this trial knitting stage, the manual changeover switch 24 is changed over to the contact 242 on the side of the tension setter 11, so that the tension signal T of the tension setter 11 is input to the current amplifier 15 via the comparison point 14. Become.
Then, in the main knitting process, the manual changeover switch 24
It is switched to the contact 241 on the side of the memory device 20, and therefore the memory device 20 generates the tension signal Ti in accordance with the knitting pattern Pi, and the contact 2 of the manual changeover switch 24.
It is sent to the comparison point 14 via 41 to set the tension.

The tension adjusting means 3 is not limited to the one shown in the drawing, but may be replaced by any other known method such as a washer type or a thread bending type.

In all of the above examples, the target tension value in the main knitting process is set by changing it to the optimum tension value obtained in the trial knitting process in correspondence with the knitting pattern Pi. Alternatively, a constant target tension value common to all knitting patterns Pi may be set. Even in this case, since the reference yarn length Li corresponding to the knitting pattern Pi is the yarn length at which the optimum stitch and texture are obtained in the trial knitting process, the optimum stitch and texture are reproduced in the main knitting process. Is what you can do. Since the yarn length deviation ΔL appears to be somewhat large, the above-described embodiments are preferable in terms of control stability.

[0023]

In the present invention, in the main knitting, the data of the optimum stitches and the texture obtained by the trial knitting are used as they are, so that the optimum stitches and the good texture can be reproduced, and the actual knitting is possible. Since the change is controlled to the optimum set tension corresponding to the pattern, the changed set tension is an approximate value for obtaining the optimum stitch and texture, so it is possible to minimize the tension correction amount. Yes, stable control can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram for realizing a control method of the present invention.

FIG. 2 is a graph of stored contents.

FIG. 3 is a block diagram of another embodiment for realizing the control method of the present invention.

FIG. 4 is a graph of stored contents.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Knitting yarn 3 Tension adjusting means 10 Motors 11, 12, ... 1n Tension setting device 13 Switching device 14 Comparison point 15 Current amplifier 18 Thread length measuring device 19 Comparator 20 Memory device 21 Knitting pattern memory device

Claims (2)

[Claims] 1. A method of obtaining a deviation between a target yarn length determined in advance corresponding to a knitting pattern and a yarn length actually consumed in the knitting process, and controlling a yarn feeding tension of a knitting yarn according to the deviation. In the above, the target yarn length is a yarn length when the tension is set so as to optimize the stitch size and texture of the actual knitting in the trial knitting. 2. A method of obtaining a deviation between a target yarn length predetermined corresponding to a knitting pattern and a yarn length actually consumed in the knitting process, and controlling a yarn feeding tension of a knitting yarn according to the deviation. In the trial knitting process, the optimum set tension and the reference yarn length at that time when the tension is set so as to optimize the stitch size and texture of the actual knitting corresponding to the knitting pattern are stored, and in the main knitting, A tension control method for a flat knitting machine, characterized in that the target set tension and the target yarn length are respectively changed to the optimum set tension and the reference yarn length corresponding to the knitting pattern at that time.