JPS584850A - Weaving method by air jet loom using auxiliary nozzle - 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 weaving method using an air jet loom. The purpose is to propose a weaving method that can stabilize weft insertion over a wide range of yarn types, improve weaving efficiency, and improve fabric quality.

Air jet looms have only a short history of practical use, and there is little room for improvement in terms of weaving efficiency and fabric quality.

Among these, the air jet flow that causes the weft yarn to fly is easily diffused, causing a rapid drop in flow velocity, weakening the traction force on the weft yarn, and becoming a major factor in reducing weaving efficiency and fabric quality. As a countermeasure to this problem, measures have been taken to install auxiliary nozzles or air guides in the weft flight direction, but these methods include increasing the loom rotation speed, widening the weaving width, or weft type (collection, fineness, etc.). , number of filaments, etc.), it became difficult to insert the weft efficiently and stably, and the quality of the fabric also deteriorated.

In conventional weaving, the ultimate goal was to make the weft reach a predetermined weaving width, and measures were taken to increase the traction force by increasing the injection pressure, amount, or duration of the air jet. If the traction force is simply increased, the tips of the weft threads in flight may get tangled, resulting in insufficient yarn length and not reaching the weaving width, or even if they do reach the weft, they may be bent or unraveled on the way, causing the machine to stop. The weaving efficiency may decrease due to
There was a drawback that the quality of the fabric deteriorated due to knot defects.

This invention was made in view of the above-mentioned problems, and unlike the conventional method of grasping the weft flight condition by relying on sense, it established a method to quantitatively grasp the weft flight condition, and the mechanism of the conventional weft flight defect has been established. This weaving method was developed based on this knowledge. The gist of the present invention is that when weaving a weft yarn using an air jet loom, when the weft yarn is pulled and flung by air jets from a main nozzle and a plurality of auxiliary nozzles, the traction force of the jet air is sequentially increased in the direction in which the weft yarns fly. This is a weaving method using an air jet loom combined with an auxiliary nozzle, which is characterized by the fact that the auxiliary nozzle injects air.

An air jet loom equipped with an auxiliary nozzle usually has a structure as shown in FIG. That is, on one side of the loom body 1, there are a weft cheese 2, a feed roll 3, a storage pipe 4, a gripper 5, a main nozzle 6, and n auxiliary nozzles 71 overflowing the weft flight path of the loom body 1. 72...7n is installed. The feed roll 3 pulls out the weft yarn 8 at a constant speed as it rotates, the storage pipe 4 stores the weft yarn 8 in a U-shape by suction air, and the gripper 5 pulls out the weft yarn 8 at a constant speed by the rotation of the loom crank. It opens and closes to grip and release the weft thread 8. The main nozzle 6 has a yarn guide hole inside, and injects the pressurized air sent through the pressure air pipe 10 to the weft yarn 8.
is made to fly towards the loom main body part 1.

The weft yarn passes through the auxiliary nozzles 7, . The weft is inserted with the help of the jet air flow of 72...7n.

Generally, in such an air jet loom, the motion of each part is controlled in conjunction with the rotation angle of the crank, and one weft insertion is performed during one rotation of the crank. Weft insertion is performed only when the gripper 5 is open, and weft thread withdrawal from the feed roll 3 is performed continuously, so the weft thread 8 pulled out when the gripper is closed is stored in the storage pipe 4, and the gripper is opened. and fly away all at once. When the stored weft yarns are exhausted, the weft yarns fly while being restricted by the feed speed of the feed rolls 3. Therefore, the -th weft insertion consists of a free flying part where the weft flies freely and a restrained flying part where it flies while being restrained.

Based on the results of quantitatively understanding and evaluating the flying state of weft insertion, the present inventors found that weft insertion stabilizes as the weft tip speed moves away from the main nozzle during free running as it flies without decelerating. They discovered that

In the conventional air jet loom of this type, the air injection pressure, injection amount, injection direction, etc. of the plurality of auxiliary nozzles are generally set to be constant. Here, the flow velocity of the air jetted from the main nozzle decreases rapidly as it goes away from the nozzle, so the relationship between the distance from the main nozzle, the air flow velocity, and the weft tip speed in the air jet loom of this method is as shown in Figure 2. He was behaving.

In other words, the air velocity curve ■ decreases as it moves away from the main nozzle, and becomes constant when it reaches a distance where the air velocity of the auxiliary nozzle dominates, and the weft traction force becomes constant. On the other hand, the flying speed of the cotton weft tip Curve ■ is accelerated from a stationary state inside the main nozzle to position A where the main nozzle injects and its traction force reduces the influence of the main nozzle, and from then on, the constant traction force of the air flow controlled by the auxiliary nozzle maintains a constant velocity. Fly without. Then, the free flight of the weft yarn stored in the storage pipe ends at B, and the weft yarn is inserted to the width edge of the fabric by performing a restricted flight controlled by the withdrawal speed of the feed roll. In this way, weft insertion can be stabilized if the weft yarn flies without deceleration in the free flying region, especially in the region controlled by the auxiliary nozzle.

However, in reality, any type of yarn has uneven fineness, uneven bunching, uneven oil adhesion, or fluff to a greater or lesser extent in the yarn length direction, so even if the air flow rate is constant, it acts on the yarn. The traction force is not constant. Therefore, the yarn speed of each part in the length direction of the weft yarn during flight is not constant, and the weft yarn may come loose, tangle, or bend in the middle.1. It can lead to loom stops and cause textile defects such as cotton tube defects. This invention was achieved based on the investigation of the cause of the above-described poor weft flight.

This weaving method will be explained using FIGS. 1 and 3.

The traction force (curve ■) of the injected air temporarily decreases between the main nozzle 6 and the first auxiliary nozzle 7, but the auxiliary nozzle 7 injects air to increase the traction force in the flight direction, so it is auxiliary. The pulling force of the air ejected from the main nozzle 6 and the auxiliary nozzle 7 increases as the area moves to a region dominated by the air ejected from the nozzles 71, 72, . Therefore, the weft tip speed (curve ■) is first accelerated by the traction force of the main nozzle 6,
The auxiliary nozzles 7, . Under the control of the traction force of 72...7n, it is accelerated and runs free, and when the stored weft yarn finishes flying and running, it shifts to restrained flight and weft insertion ends.

For this reason, even if the weft has yarn irregularities such as uneven fineness, uneven bunching, uneven oiling, or fluff, which causes a difference in the traction force acting in the middle of the weft and causes a slight change in speed, the weft tip will be the strongest. Since it is being towed, it absorbs speed changes during the process and accelerates, allowing stable weft insertion without causing phenomena such as tangling or bending.

There are various methods for the auxiliary nozzle to inject air in order to sequentially increase the traction force of the injected air. An example of this aspect will be described below.

■ Adjust the air jet direction of the auxiliary nozzle.

The closer the jetting direction is to the weft flying direction, the more the traction force can be increased. In particular, as shown in FIG. 5(a) or (b), the angle θ of the injection direction with respect to the flying direction is changed to the horizontal direction or the vertical direction. In the figure, 12 is the special liquid 11.
This is a thread guide groove provided in the

■ Adjust the position of the injection hole of the auxiliary nozzle.

As shown in FIG. 6, the smaller the distance H1 between the center of the thread guide groove 12 of the special liquid 11 and the injection hole of the auxiliary nozzle 7, the smaller the distance between the lower edge of the opening of the thread guide groove 12 and the injection hole, the greater the traction force. It can be made higher.

■ How to adjust the diameter of the thread guide groove of a reed If the diameter and cross-sectional area of the thread guide groove 12 are made small, the air flow velocity can be increased and the traction force can be increased. The diameter of the yarn guiding groove 12 in the running direction can be reduced to the diameter D2, and the traction force of the jetted air can be increased in the flying direction.

■ Method of adjusting the injection air of the auxiliary nozzles The traction force can be gradually increased by increasing the injection air pressure or air amount of the auxiliary nozzles located far from the main nozzle.

Alternatively, several auxiliary nozzles may be grouped together to form one block, and the number of auxiliary nozzles may be successively increased to increase the traction force.

Traction and force in this invention can be measured by the following method.

Operate the loom in advance and check the gripper opening angle θA and closing angle θB.
Any crank angle θAR during this period (θA〈θAk≦θB)
The arrival and distance of the weft tip from the main nozzle at , for example, is measured using a strobe.

Crank angle Weft tip reaching distance θAI LAI (However, LAI≧20
cIrL) θA 2 LA 2 θAk LAk θAn(""θB) LAn (-LB) Next, the loom is stopped, and the weft 14, whose base end is tied to the strain gauge 13 as shown in Fig. 4, is inserted through the main nozzle 6. , length LAk
(k = 1.2-...n) in the thread guide groove 1 of the special liquid 11
To 2-, take it out. Then, the main nozzle 6 and reinforcement nozzle 7 are injected with the air injection pressure and injection timing set to predetermined conditions, and the conveying force Fk acting on the weft yarn 14 is measured with a strain meter. Similarly, the conveying force F from LAl to LAn
,, F2...Measuring Fn In this invention, the loom is adjusted so that F<F2<...<Fn.

Note that in the case of LAIo<20cIIL, the influence of the conveyance force of the main nozzle is significant, and F, (F, 2 may not be achieved).

Example Using a special liquid auxiliary nozzle type air jet system Warp cupro rayon yarn 50 denier/30 filament weft, cupro rayon yarn 7゛5 denier/4
5 filament warp density 90/3.78cnL
X 2 pieces/feather weft density 125 pieces/3.78cML
When weaving a taffeta fabric with the fabric design, the weaving conditions were as follows.

(Crank angle) Gripper °-opening 950-240° Main nozzle injection 900-2400 Auxiliary nozzle injection No., 1950-175O No. 2 125o-2o5O No. 3 1500-23oO No. 4 1800-260° No. 5 2200 ~3000 injection air pressure Main nozzle 2.2 Ky/m Auxiliary nozzle 4.0 g/d In addition, the injection hole positions were adjusted so that the traction force at each auxiliary nozzle position was as follows.

Auxiliary nozzle position traction force No. 1 2.5X10-2X75. grNo,
2 2.6 g No, 3 2.7X10””X75, 9rNo
, 4 2.8''sNo, 5
2.9 tt Comparative Example Same design fabric as Example, same weaving conditions. However, weaving was performed by adjusting each auxiliary nozzle so that the traction force at each auxiliary nozzle position was 2.8:X 1.0-2X 75 ir.

The weaving efficiency and fabric quality of Examples and Comparative Examples are as shown in the table below.

[Brief explanation of the drawing]

Fig. 1 is an overall schematic diagram of the air jet loom, Figs. 2 and 3 are graphs showing the weft flying speed in conventional weaving and this weaving method, respectively, Fig. 4 is a diagram showing a method for measuring traction force, Figure 5 (a), Cb) Plan view and side view showing the direction of air injection from the auxiliary nozzle. Figure 6: Drawing showing the position of the auxiliary nozzle. Figure 7: A front view of a special reed with a tapered groove diameter. be. DESCRIPTION OF SYMBOLS 1... Loom body part, 2... Weft cheese, 3... Feed roll, 4... Storage pipe, pu, 5... Gripper 16... Main nozzle, 7,7. ．． 7□...7n
...Auxiliary nozzle, 8...Weft, 9...Cam, 10...Pressure pipe, 11...Special reed, 12...
- Yarn guide groove, 13... Strain meter, 14... Weft. Figure 1 Figure 2 Distance from main nozzle

Claims (1)

[Claims] (1) In weaving using an air jet loom, when the weft yarn is pulled and flung by the jet air of the main nozzle and a plurality of auxiliary nozzles, the auxiliary nozzles are directed in the direction of the weft yarn flight in order to sequentially increase the traction force of the jet air. A weaving method using an air jet loom combined with an auxiliary nozzle, which is characterized by jetting air.