JPH03220345A - Weft detector - Google Patents

Abstract

PURPOSE:To obtain the subject apparatus free from kick back of a weft due to a return spring and capable of accurate detection of the weft by returning a detection needle utilizing a restoring force of the end part of the inserted weft. CONSTITUTION:An inserted detection needle 15 is returned to the original position by utilizing a restoring force of the end part of an inserted weft due to tension generated between a selvage part 23 on the opposite side of the cloth fell 22 to the weft insertion side and a catch cord 28. The repulsive force of a return spring of the detection needle can be reduced to zero or a remarkably low value and mal-operations of a newly inserted weft due to kick back by the detection needle can be prevented thereby.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a weft detection device for a shuttleless loom, and particularly to a mechanical device using a detection needle.

(Prior art) In a conventional device that detects weft yarns using a detection needle, the detection needle is placed facing the reed and closer to the front of the weaving than the weft flying position, and the detection needle is moved toward the front of the weaving by the weft that has been beaten. The driving operation is electrically detected to determine whether weft insertion has been performed normally.

The detection needles are placed with their tips inserted between the warp threads in a direction diagonally intersecting the reed feathers when viewed from the front of the loom, and even if there are no weft threads, they are pushed by the reed feathers and driven into the loom. However, when there is no weft thread, the reel returns to its original position due to the repulsive force of the return spring as the reed moves backward, so the presence or absence of the weft thread has been detected based on the presence or absence of this return action.

The weft yarn detection device with the above structure returns the inserted detection needle while slidingly contacting the warp yarns, and since the returning operation must be performed reliably, it is necessary to use a return spring with a large repulsive force. there were.

(Problem to be solved by the invention) However, in the conventional structure described above, since a return spring with a large repulsive force is used, the detection needle kicks out the properly driven weft yarn from the front of the weave, causing the loom to stop. There is a problem that sometimes happens. In addition, since the detection needle is inserted between the warp threads, when using a warp with a high warp density or a warp with poor slippage such as a spun thread, the detection needle may not return even if there is no weft thread (even if the detection needle does not return to its original position, it may cause the loom to stop incorrectly). Furthermore, there is a problem in that warp fuzz and vertical streaks are generated in the woven fabric.Also, since the detection needle and the reed collide each time the reeding operation is performed, there is a disadvantage that the reed and the detection needle are likely to have free time. If the angle between the detection needle and the reed is not appropriate, there is a problem that a severe reed ring will be formed and the needle will break.Furthermore, the presence or absence of the weft cannot be detected until the reed has retreated to a certain extent, resulting in weft insertion errors. Since the loom is stopped after that, there is a problem that the reed is not placed in the correct position.

On the other hand, there is a method that avoids contact between the detection needle and the reed by providing a slit in the reed that allows the detection needle to pass through, but since the reed has a slit, the reed must be changed when changing the fabric width. However, there is a problem in that it is complicated and reduces the operating rate of the loom. In addition, since the inserted weft ends are simply held on both sides of the slit, they are easily pushed into the slit by the detection needle, which is biased by a return spring with a large repulsive force, resulting in no weft insertion. There is a problem in that the loom operates in a similar manner, causing the loom to stop incorrectly.

Although there is a technique disclosed in Japanese Patent Publication No. 52-14793 as a means to solve the above-mentioned problems, it is difficult to adjust the position of the detection needle and the timing difference between the weft detection timing and the yarn edge cutting timing. Not put to practical use.

The present invention aims to solve the above problems,
There is no risk of the weft kicking due to the return spring,
An object of the present invention is to provide a weft yarn detection device that can accurately detect weft yarns even during high-speed operation, eliminates the risk of wasting the reeds or detection needles, and can easily respond to changes in weaving width. It is said that

(Means for Solving the Problems) The weft detecting device of the present invention detects the weft thread which is caused by tensioning the driven detection needle between the opposite weft inserting side selvedge 23 of the weaving fabric and the catch cord 28. End 2 of weft 27
The restoring force of the sensing needle 7a is utilized to return the sensing needle to its original position, and the repulsive force of the return spring of the sensing needle can be reduced to zero or extremely small. That is, in the device of the present invention, between the ear portion 23 on the side opposite to weft insertion of the driven weft 27 and the catch cord 28 that grips the yarn end 27a of the weft, the tip end 15a is located on the back side of the driven weft. A sensor 7 for detecting the swinging movement of the detection needle and a lifting mechanism 12 for lifting and lowering the detection needle 15 in synchronization with the shading operation are provided. A yarn guide 3 having a slit 4 facing the detection needle 15 at a distance from the reed feathers is provided on the front side of the reed 2, and the yarn guide detects the weft while holding the end 27a of the inserted weft. The detection needle 15 is pressed against the needle 15 and swung toward the woven fabric, and the sensor 7 detects the oscillation motion, and the detection needle 15 is detected by the restoring force of the driven weft 27 tensioned by the catch cord 28. It is characterized by restoring.

(Function) The weft detecting device of the present invention uses the restoring force of the driven weft 27 to return the swung detection needle 15, so there is no need for a return spring, and even if it is necessary, it is extremely small. It is possible to prevent malfunctions caused by newly driven weft threads being kicked out by the detection needles as much as possible. The weft pushing member 3 is separate from the reed 2, so even if the fabric width changes, there is no need to replace the reed, and it is only necessary to move the weft pushing member 3. Since the detection needle 15 is located between the ear portion 23 on the side opposite to the weft insertion side and the catch cord 28, there is no need to insert the detection needle between the warp threads, and there is no risk of fuzzing or vertical streaks occurring in the warp threads. Since the weft pushing member 3 is provided on the front side of the reed at a distance from the reed feathers, the detection needle 15 and the reed 2 will not come into contact with each other (no reed ring or needle breakage will occur). Since the weft ends are held on both sides of the slit, the tension of the weft can be maintained at a high level when the weft is detected.

(Embodiment) The figures show an embodiment of the present invention, in which FIG. 1 is a perspective view of a weft detection device, and FIG. 2 is a plan view of the main part of FIG. 1.

In the figure, 1 is the sled, 2 is the reel mounted on the sled l, and 3
2 is placed upright on the front side of the weave with a gap from the reed feathers of reed 2.
A wooden thread guide, 4 is a slit formed by the thread guide 3.3, 5 is a presto beam, 6 is a bracket fixed to the presto beam 5, 7 is a proximity sensor provided at the upper tip of the bracket 6, 8 is a An arm is pivotally supported by a pin 9 on a bracket 6, a cam roller 1o is attached to the base end of the arm 8, a camshaft 11 rotates in synchronization with the crankshaft of the loom, and a camshaft 12 is fixed to the camshaft. Cam, 1
3 is a tension spring that presses the cam roller 1o against the cam 12; 15 is a detection needle pivotally supported by a pin 16 at the tip of the arm; the tip 15a of the detection needle is connected to the slit 4; It is located opposite to. 17 is the detection needle 15
A return spring 18 biases the detection needle 15 counterclockwise in the figure, and a stopper 18 restricts the counterclockwise swing of the detection needle 15. The base end is regulated at a position close to the sensor 7.

20 is a cutter, 21 is a woven fabric, 22 is a front of the woven fabric 21,
23 is the selvedge of the woven fabric 21 on the side opposite to weft insertion, 24 is the warp inserted through the reed 2, 25 is the opening of the warp, 26 is the weft inserted into the opening 25, 27 is the weft that has been inserted, 28 is a catch cord, and 30 is a twining thread device. catch code 28
is composed of 4 to 6 pieces, and a lever-type tension adjustment device is provided for each piece to maintain a constant tension while absorbing loosening when the opening is closed.

The weft detection method will be explained based on FIGS. 3 to 8. As shown in Fig. 1.2, when the weft yarn 26 is inserted, the beating operation is started. The yarn guide 3.3 moves the inserted weft yarn toward the detection needle 15 while holding the end portion 26a of the inserted weft yarn. The yarn guide 3.3 brings the weft end 26a into contact with the detection needle 15 (the third
solid line in the figure and Figure 4), the reed 2 is on the weaving front 22 and the weft 26
At the same time as the
Swing to the right in the diagram (imaginary line in Figure 3 and Figure 5)
. This swinging action causes the base end of the detection needle 15 to move away from the sensor 7, so that the presence of the weft thread 26 can be detected. When there is no weft end, the detection needle 15 passes through the slit 4 and does not swing.

At the same time that the reeling ends and the reel 2 starts its backward movement, the positions of the upper and lower threads of the warp 24 and the catch cord 28 are switched, and the entangling thread device 30 operates to remove the end of the newly driven weft. 26a. Finished weft end 2
7a is tensioned between the selvedge 23 of the woven fabric and the catch cord 28, so as the yarn guide 3 moves backward, the tip 15a of the detection needle returns to its original position due to the restoring force of the weft end 27a. (solid line in FIG. 6 and FIG. 7).

Immediately after returning, the cam 12 swings the arm 8 to the upper left in Fig. 6, moves the detection needle 15 upward, pulls out its tip from the end of the weft (imaginary line in Fig. 6), and moves it downward again. The tip 15a of the detection needle is moved to detect the newly re-stretched weft 2.
The weft end portion 27a of No. 7 is placed adjacent to the reed side and waits for the next weft insertion operation (FIG. 8).

(Effects of the Invention) As described above, the present invention uses the restoring force of the end of the inserted weft yarn to return the detection needle, so that an active return motion is applied to the detection needle, so that the return spring is This eliminates the need for repulsive force, and even if it is necessary to stabilize the detection needle, the repulsive force may be extremely small. In addition, since the yarn guide is separately provided on the front side of the reed, there is no need to replace the reed even if the fabric width changes, and the operating rate of the loom will not be reduced.The detection needle and reed are in contact with each other. A detection needle is installed between the end of the selvage on the cotton insertion side and the catch cord, so there is no warp fuzz or vertical streaks, and the warp density and Not affected by thread type. In addition, since the weft end is pushed into the detection needle by a plurality of thread guides and detected, the tension of the weft is large when the weft is pushed in, and malfunctions due to kicking of the weft are prevented as much as possible.

Furthermore, since a weft insertion error is detected during the reshaping, the position at which the reel stops is good. As a result of the above, it is possible to provide a weft yarn detection device that can accurately detect weft yarns even during high-speed operation.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the weft detection device according to the present invention, FIG. 2 is a plan view of the main part of FIG. 1, and FIGS. 3 to 8 are explanatory views of the operation of the weft detection device according to the present invention, Figures 3 and 6 are side views, Figures 4 and 5 are plan views of main parts corresponding to the state in Figure 3, and Figures 7 and 8 are main parts corresponding to the state in Figure 6. FIG. In the figure, 3: Yarn guide 7: Proximity sensor 15: Detection needle 4 Nislit 12: Cam 22: Before m 23 Ni - Ledge 27: Weft thread that has been driven

Claims (1)

[Claims] Between the ear (23) on the opposite side of the weft insertion side of the driven weft (27) and the catch cord (28) that grips the end (27a) of the weft, the tip (15a) A detection needle (15) adjacent to the reed side is pivotally supported to be swingable in the reed driving direction, and a sensor (7) that detects the swinging movement of the detection needle
) and an elevating mechanism (12) for raising and lowering the detection needle (15) in synchronization with the retard beating operation, and facing the detection needle (15) at a distance from the retard feathers on the front side of the retard (2). A thread guide (3) having a slit (4) is provided, and the end (26a) of the weft thread (26) immediately after weft insertion is held by the thread guide and pressed against the detection needle (15). 15
) is swung toward the woven fabric, and the sensor (7) detects the swiveling motion, and the detection needle (15) is activated by the restoring force of the inserted weft (27) tensioned by the catch cord (28). A weft detection device characterized by returning the weft.