JPS6017152A - Weaving step preventing method of loom - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing weaving steps in connection with the motorized unwinding movement of a loom.

When a loom stops due to a weft insertion error, a common method for repair is to reverse the loom, remove the defective yarn caused by the weft insertion error, and restart the loom. At this time, weaving steps called stop marks usually occur on the woven fabric. This is due to the fact that the weave stitches are not in the correct position and there is a temporary lack of beating force when the loom is started.

In other words, if the loom stops due to a weft insertion error and is then reversed, the take-up roll will reverse by the amount it has taken up, and the delivery beam will also reverse by the same amount. However, the weave does not move by an amount corresponding to that amount. The reason is that there is a frictional contact resistance between the warp threads and the presto beam. That is, the tension between the sending beam and the opening of the warp is Fl, the tension between the opening and the presto beam is F2, and the tension between the presto beam and the take-up roll is F3.
This is because the loom is operated with the relationship Fl<F2<F3 between them, and when the loom is reversed, the cloth opening does not move.

Therefore, an object of the present invention is to reverse the magnitude relationship of tension during reverse operation.

Based on the above object, the present invention reverses the sending beam, sets the tension so that the relationship Fl>F2>F3, and the value of the tension difference (F2-F3) is a presto beam. The frictional contact resistance of the cloth is made to be greater than the frictional contact resistance of the cloth, and the cloth opening is moved to a predetermined position during reverse operation.

However, if the machine continues to operate as it is, the tension at which the warp threads are sent out is high, and weaving flaws, generally called thick film, occur. On the other hand, if the tension is returned to normal, the beating force at the time of startup will be insufficient, and weave flaws, called so-called thin films, will occur.

Therefore, another object of the present invention is to eliminate the lack of beating force at the initial stage of start-up by controlling the position of the cloth opening.

Therefore, in the present invention, at the initial stage of start-up, the warp yarns are fed forward in a normal direction, and the weaving head is moved slightly backward from the normal position, so that the warp yarns are placed in a position commensurate with the lack of beating force.

Hereinafter, the method of the present invention will be specifically explained based on examples shown in the drawings.

First, FIG. 1 shows the sending-off movement, shedding movement and winding movement of the loom in relation to the warp yarns 1. The warp yarns 1 are wound around a delivery beam 2, pass through a tension roll 3, become almost horizontal, form an opening 5 with a belt 4, intersect with the weft yarns 7 at the opening 6, and form a reel 8. A woven fabric 9 is formed by the beating motion. This woven fabric 9 is, for example, a roll-shaped fixed presto beam 10.
The cloth is changed direction by the guide rolls 11, 12, and is wound around the outer periphery of the winding roll 13, and then wound onto the cloth winding beam 14 one after another. The delivery beam 2 and the take-up roll 3 are driven by a delivery motor 15 and a loom driving motor 16, respectively.

Of course, this loom driving motor 16 serves as a power source for the main movement of the loom.

Next, FIG. 2 shows a control system for the above-mentioned feeding motor 15. A motor speed command control device 17, which is the main part of the control system, is connected to the motor 15 via a summing point 18 and a drive amplifier 19.

A tacho generator 2o and an encoder 21 are mechanically connected to the motor 15, and the tacho generator 2o is connected to the summing point 18, and the winding diameter detector provided on the encoder 21 and the sending beam 2 22 are both connected to the motor speed command control device 17. This motor speed tH command control device 17 inputs the weft insertion error signal A, preparation signal B, operation signal C, and feed-out tension detection signal E, winding diameter signal F, and motor rotation amount signal E to generate a motor speed command signal. In addition to issuing G, it also performs necessary sequential control operations. Note that the feed tension detection signal is connected to the motor speed command control device 17 via the startup completion switch 23.

Next, the method of the present invention will be explained with reference to FIGS. 3 and 4.

The motor speed command control device 17 receives signals such as the delivery tension detection signal D, the motor rotation amount signal E, and the winding diameter signal F, generates an appropriate motor speed command signal G, and sends it to the drive amplifier 19. Here, the drive amplifier 19
controls the rotation of the motor 15 based on the command. Note that the rotation of this motor 15 is controlled by the tacho generator 2o.
The motor 15 always rotates at a rotation speed close to the target value after the feed bank control because the rotation speed is detected by the rotation speed and fed back negatively to the addition point 18.

By the way, when a weft insertion error occurs, the weft insertion error signal A is input, so the motor speed command control device 17 immediately stops the rotation of the motor 15 as shown in FIG. 3(a), and The input state to the horizontal insertion error signal is stored. During this time, the worker
Then, the winding roll 13 is reversed by one bit.

At this time, the defective weft thread 7' should theoretically return by one pick from the position of the weft opening 6 in Figure 4 (A), but for the reasons already mentioned, it should return as shown in Figure 4 (B). , only returns less than 1 bit. In this state, necessary work is performed to remove defective yarns and repair the warp yarns.

Thereafter, the "H" level preparation signal B is input to the motor speed command control device 17 for a certain period of time T1. Therefore, the motor speed command control device 17 confirms the presence of the preparation signal B and rotates the feeding motor 15 in the reverse direction for a predetermined time T2, so that the tension difference (F2-F3) is determined by the friction in the presto beam 10. until the contact resistance is greater than the actual contact resistance. In this way, the tension of the warp threads l is set to be greater than the frictional contact resistance at the presto beam 10. At this time, the cloth opening 6, as shown in FIG. 4(c),
Move back by ΔL from the normal position.

Thereafter, the motor speed command control device 17 rotates the motor 15 in the normal rotation direction for an appropriate time T3 at the same time as the completion of the reverse rotation, and the difference between the amount of reverse rotation and the amount of normal rotation is caused by the insufficient driving speed at the time of starting the loom. Set the warp thread tension as necessary to prevent this. At this time, the position of the cloth opening 6 is slightly retreated from the normal position by ΔI, as shown in FIG. 4(d).

After that, or immediately after that, the operation signal C at the H'' level is input, so the loom driving motor 16 is immediately activated and shifts to a steady rotational speed at a predetermined rising slope.

On the other hand, at the time when the operation signal C is input, the motor speed command control device 17 stores the rotational speed of the motor 15 before stopping, and immediately starts the motor I5 at this speed. When the loom reaches a steady rotational speed, the start-up completion switch 23 is turned on, so that the sending tension detection signal is input to the motor speed command control device 17 for the first time. In this way, the delivery motor 15 reaches its normal rotational speed.

Here, the rise of the motor 15 is set to be steeper than the rise of the motor 16. The reason for this is that the weaving sheath 6 is returned to its normal position before the loom driving motor I6 reaches a steady rotational speed. Therefore, on the drawing, the area SO=area area S1 is set.

Note that if there is no lateral insertion error, there is no need to rotate the motor I5 in the forward rotation direction in advance. Therefore,
The reversal time of the motor 15 is as shown in FIG. 3(b).
It is set shorter than when there is the above-mentioned width insertion error. Here, the relationship of area SO=O=S2 is set. By operating in this way, even if the driving speed is reduced at the beginning of the loom startup, the generation of weaving rows will be prevented.
It can definitely be prevented.

In the present invention, when pulling back the warp threads, a tension sufficient to overcome the contact resistance at the presto beam is set, so that when the weft threads are repaired, the weave is reliably retreated by reversing the feed-out motor, and the weave is reliably pulled back at the initial stage of starting up the loom. Since the feed motor is rotated in the forward direction in advance in response to insufficient reeding force, appropriate reeding force can be obtained even in the early stages of starting up the loom, thus preventing the occurrence of weaving steps. . Further, in an embodiment in which the control system stores a signal indicating a width insertion error, it is possible to appropriately control the rotational movement depending on whether or not there is a width insertion error.

[Brief explanation of the drawing]

Fig. 1 is a skeleton diagram showing the movement path of the warp threads, and Fig. 2 is a block diagram of the control system of the feeding motor. 1.Warp thread, 2.Feeding beam, 6.Weave opening, 7
...Weft, 8...Reed, 1o...Brace beam,
13...Roll to wind up, 15...Motor for sending out, I6...Motor for driving the loom, 17...Motor speed command control device.

Claims (2)

[Claims] (1) When the loom stops due to a weft insertion error, the loom is reversed to process the yarn, and the feed beam is reversed with tension that overcomes the contact resistance of the presto beam, thereby returning the weave to its normal position. , after that, the feed beam is rotated in the normal rotation direction to a tension corresponding to the shortage of the reel beating force, and the weave is set at a slightly backward position from the normal position, and then the loom is started. How to prevent weaving steps on a loom. (2) A method for preventing weaving steps in a loom, which comprises memorizing a weft insertion error as a cause of a loom stoppage, and controlling the rotation of a delivery beam using a loom operating signal or a preparation signal.