JPH10168707A - Weft braking apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the yarn breakage and slackening at the end of weft- insertion by placing a braking member to apply an air jet against a weft through a floating member between a weft measuring and storing apparatus and a main nozzle for weft-insertion, thereby finely adjusting the braking power according to the kind and fineness of the weft. SOLUTION: A weft-braking apparatus composed of a floating member 12 and a fixed guide 14 is placed between a weft-measuring and storing apparatus and a weft-insertion main nozzle. An air jet is blown against the floating member 12 through a blowing nozzle 13, a solenoid valve 15 connected to the blowing nozzle 13 is connected to a compressed air source through a pressure-regulation valve 16 and the bending of the weft Y is adjusted by controlling the pressure of the air jet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weft braking device for a shuttleless loom. The present invention relates to a weft braking device that alleviates a sudden increase in tension caused by a weaving pin serving as a weft restraining member.

[0002]

2. Description of the Related Art In a weft insertion of a fluid jet loom, a weft is wound around a drum of a weft length measuring and storing device a predetermined number of times and is temporarily stored. The weft yarn is unwound from the drum and pulled out by the retraction of the yarn pin reciprocally driven by the electromagnetic solenoid. When the yarn is pulled out by one pick, the yarn pin returns and is prevented from being pulled out. Ends. The graph in FIG. 6 shows the change in the weft tension during weaving. As shown in this graph, the very high tension is applied to the weft at the moment of stopping pulling out (about 260 °), and the yarn breaks, or The recoil of the blockage caused the yarn to loosen, and this phenomenon appeared more frequently at higher speeds. For this reason, weft braking devices aiming to suppress a sudden rise in tension are disclosed in Japanese Patent Application Laid-Open Nos.
Various proposals have been made in -150442 and the like.

[0003] Japanese Unexamined Patent Publication No. 7-48760 discloses a method in which a plurality of fixed thread guide parts and at least two movable thread guide parts mounted on a rotating body are provided, and the rotating body is fixed by rotating the rotating body. An electric drive means such as a solenoid is used as a drive means for rotating the rotating body, and a device for further limiting the rotation and a rotated rotating body are used for bending and bending the path of the yarn guided by the yarn guiding component. A return spring for returning to the original position is provided.

Japanese Patent Laid-Open Publication No. 7-150442 discloses an elastic blade made of a ferromagnetic material and a flat support plate made of a non-magnetic material. It is a device that brakes the yarn running between them, using an electromagnet whose excitation can be adjusted as a means to press the elastic blade against the support plate, and pushing the blade against a stop pin fixed on the opposite side of the yarn path. Preloaded.

[0005]

Both of the above-mentioned prior arts are capable of securing a quick and strong braking force by directly applying an electromagnetically driven rotating body or elastic blade to the weft. It was possible to adjust the braking force by changing the bending angle or the holding force of the weft. However, since the jetting power of the weft insertion main nozzle and auxiliary nozzle is appropriately adjusted depending on the yarn type and fineness of the weft,
Because the flying weft has different tension and inertial force, it is desirable that it be continuously variable and finely adjustable even during operation. Was very complicated and time-consuming.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention provides an indirect braking force by blowing or jetting an air jet, which can be easily adjusted in pressure, onto a driven member to bend or pinch the weft through the driven member. Is to be granted. Here, the part that does not spray directly onto the yarn is that the part that receives the air jet of the flying weft is linear and the track does not always pass through the center of the air jet because the track is meandering, and it is sufficient and stable This is because a braking force cannot be applied to the motor.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a schematic view of a weft insertion device in an air jet loom, in which a weft Y is drawn out of a cheese 2 and temporarily stored in a weft length measuring and storing device 3, and thereafter, the weft is injected by a weft insertion main nozzle 7. The length is measured by one pick from the length measuring and storing device, pulled out, and inserted into the warp shed.

The weft length measuring and storing device 3 includes a yarn winding drum 4 and a yarn winding pin 5 reciprocally driven by an electromagnetic solenoid. The yarn winding pin 5 is engaged with the outer periphery of the drum 4 at the time of weft insertion. By retreating from the state, the weft Y is unwound from the drum 4, pulled out and unwound a predetermined number of times, and then controlled by the control circuit 6 so that the yarn pin returns to its original position and prevents pulling out. Is done. The retraction of the yarn pin is controlled based on the weft insertion start timing preset in the control circuit 9 of the loom main body. The length of the weft inserted into one pick is measured by adjusting the diameter of the drum and the number of windings.

One weft braking device 1 is provided between the weft storage device 3 and the main nozzle 7 for one weft color.
In the first example shown in FIGS. 1 and 2, the weft is bent to brake. A driven member 12 having a weft insertion hole and a fixed guide 14 having an insertion hole in a straight line sandwiching the driven member are provided on the weft traveling path, and the driven member 12 is slidable between the fixed guides 14. And are guided so as not to deviate. Further, a blowing nozzle 13 is attached to the lower end of the fixed guide 14 so as to be directed at right angles to the running direction of the weft Y and toward the surface 12a to be driven of the driven member. Also, a fixed guide 14 is provided so as to release the air jet flow from the blast nozzle 13.
Is formed so that one surface or a part thereof is open.

The blast nozzle 13 is connected to a solenoid valve 15,
The solenoid valve is connected via a pressure regulating valve 16 to a source of compressed air (not shown). The injection timing and injection time of the solenoid valve 15 are controlled by the control device 9 of the loom main body based on the weft insertion start timing. The solenoid valve 15
May be controlled by the control circuit 6 of the weft storage device 3 based on the drive timing of the yarn engaging pin 5.

The operation of the weft braking device will now be described. In the weft insertion state shown in FIG.
A signal of opening is input to the electromagnetic valve 15 from the
When the compressed air is injected from 3, the driven member 12 is pushed upward by the pressure of the air jet flow, and the weft Y is bent and becomes a running resistance to apply braking. Here, the braking force can be easily adjusted even during operation because the sliding amount of the driven member 12 changes by adjusting the pressure adjusting valve 16.

When the solenoid valve 15 is closed by a signal from the control device 9 and the injection is completed, the driven member 12 is closed.
Returns to its original position by gravity and the tension of the weft.
At this time, the air returns slowly due to the effect of the airflow remaining in the pipe.

FIG. 3 shows a second example of a weft braking device in which a contact resistance is added to a bending resistance for braking, and a driven member 22 is provided with a weft contact portion 22b. At the time of braking, as shown in FIG.
Is bent inside the insertion hole of the fixed guide 24 and travels along the weft contact portion, and the bending rate and the frictional force of the contact portion fluctuate by adjusting the injection pressure.

FIG. 4 shows a third example.
The fixed guide 34 is provided with a weft pressing surface 34a across the weft running path, and slides the driven member 32 having a weft pressing surface 32b opposed to the weft pressing surface. They are guided so that they can move freely and do not deviate. At the time of braking, as shown in FIG. 4B, the weft pressing surface of the driven member is pressed against the weft pressing surface of the fixed guide by adjusting the injection pressure, and the holding force fluctuates.

As described above, the mode of applying the braking force to the weft braking device of the present invention is not limited, and any device may be used as long as it applies the air jet flow to the weft indirectly.

[0016]

EXAMPLE The tension of a weft at the time of weft insertion was actually measured using the first example of the present invention. In the 190cm width of the air jet loom AEROMAX (trade name) manufactured by Ishikawa Seisakusho Co., Ltd., the number of cotton yarns is 10 and the weaving width is 180cm.
The rotation speed is 600 rpm and the weft insertion start timing is 7
It was set to 0 °. And in the weft braking device 215 °
It was set to inject for a moment. The resulting change in weft tension during one revolution of the loom is shown in the graph of FIG. The measurement point of the tension is between the weft braking device 1 and the main nozzle 7 for weft insertion.

At the end of weft insertion, the injection from the blast nozzle 13 has a slight delay such as a response time from the setting of 215 ° to the solenoid valve 15, and is injected during a period T of about 220 to 250 °. By this injection, the weft Y is about to be conveyed by the auxiliary nozzle 8 at the leading end of the flight, but is braked by the weft braking device 1 on the yarn supply side. For this reason, the weft is temporarily tensioned in the meandering traveling state, and immediately after that, the weft is loosened by the recoil, and the traveling speed is reduced. When the weaving pin 5 of the weft storage device 3 returns (approximately 265 °) to complete the weft insertion, the weft Y is suddenly stopped, and the tension shows the maximum value.

In comparison with the graph of FIG. 6 showing the result of measurement without using the weft braking device under the same conditions, it is found that the maximum value of the tension when the yarn pin is activated is lower when the braking is applied. Recognize. Therefore, it can be said that the risk of thread breakage is small. In the case of an elastic yarn, it is thought that it appears remarkably, but the slack immediately after the maximum value is small, and it can be said that the possibility of the yarn becoming slack is small.

[0019]

As described in detail above, according to the present invention, the air jet is made to act on the weft indirectly via the driven body.
By adjusting the pressure of the air jet, the braking force can be finely and easily adjusted in accordance with the type and fineness of the weft, preventing breakage and loosening of the yarn at the end of weft insertion and good quality. This has the effect that stable weaving can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a weft insertion device.

FIG. 2 is a view showing a state when the weft braking device is operated.

FIG. 3 is a diagram of a second example of the weft braking device during standby and during operation.

FIG. 4 is a diagram of a third example of the weft braking device during standby and during operation.

FIG. 5 is a graph showing a change in weft tension when the weft braking device of the present invention is used.

FIG. 6 is a graph showing a change in weft tension when a weft braking device is not used.

[Explanation of symbols]

 Y Weft 1 Weft braking device 3 Weft length measuring and storing device 5 Engagement pin 12, 22, 32 Driven member 13, 23, 33 Spray nozzle 14, 24, 34 Fixed guide 15 Solenoid valve 16 Pressure regulating valve

Claims (4)

[Claims] 1. A fixed guide through which a weft passes is provided between a weft length measuring and storing device and a main weft insertion nozzle, a driven member that applies resistance to a running weft is provided between the fixed guides, and a fixed guide is provided between the fixed guides. 2. A weft braking device according to claim 1, further comprising a fume nozzle directed in a direction perpendicular to the running weft, and pressure adjusting means connected to said fume nozzle. 2. The weft braking device according to claim 1, wherein a weft insertion hole is provided in the driven member so as to give resistance to the running of the weft by bending. 3. The weft braking device according to claim 1, wherein a weft contact portion is provided on the driven member so as to impart resistance to the running of the weft by contact. 4. The weft braking device according to claim 1, wherein the driven member and the fixed guide are each provided with a weft pressing surface opposed to each other across the running path of the weft so as to provide resistance to the running of the weft by pinching.