JPS6011112Y2 - Weft insertion device in air jet trum - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention relates to an air jet loom weft insertion device for inserting weft yarns into warp openings by jetting compressed air.

In the conventional air jet room, a length measuring device (not shown) is used.
The weft W measured to a predetermined length is temporarily stored in the weft storage device 1 as shown in FIG. The yarn passes through a weft guide 3 provided close to the weft yarn guide 3 and is inserted into the injection nozzle 4 .

From the injection nozzle 4, compressed air is injected from the reed 6 at the top of the sleigh 5, which performs an oscillating motion, toward a guide path formed by a large number of guide pieces 7 arranged at a predetermined pitch on the fabric front side, and the weft thread is The W is carried by the injected air and inserted into the guide passage, where weft insertion is performed.

The weft W is cut by a cutter (not shown) installed near the fabric.
It is cut off every time after beating.

The injection nozzle 4 is attached to the machine frame (not shown) as shown in Figure 2.
A nozzle body 10 is fitted into a fitting hole 9 formed in a bracket 8 fixed to the bracket 8 .

An acceleration tube 11 is provided at the tip of the nozzle body 10, and is fixed to the nozzle body 10 with a locking nut 12.

Further, a housing recess 13 is formed at the rear.

The accommodation recess 13 communicates with the acceleration tube 11 via a flow path 14 formed in the axial center of the nozzle body 10.
The needle 1 has a weft introduction passage 15 formed in the center.
6 are screwed together.

A groove 17 is formed in an annular shape on the rear outer periphery of the nozzle body 10, and an air supply hole 18 is formed at the bottom of the groove 17 to communicate the space groove 17 with the accommodation recess 13.

As shown in FIG. 3, the air supply holes 18 are all formed to face the axis of the nozzle body 10 and extend in a direction perpendicular to the axis.

An outer tube 1 covering the groove 17 is provided on the rear outer periphery of the nozzle body 10.
9 is fitted and fixed onto the nozzle body 10 via the bracket 8 with locking nuts 20 and 21.

A fitting hole 22 communicating with the groove 17 is formed in the outer tube 19 .

A pipe 23 for supplying compressed air is fitted and fixed in the fitting hole 22 .

As shown in FIG. 4, the pipe 23 is connected to a tank 24 for supplying compressed air, and an electromagnetic valve or mechanical valve 25 is provided in the middle.

A pipe 26 as a bypass connected to a tank 24 is connected to the pipe 23, and a throttle valve 27 is provided in the middle of the pipe 26.

The valve 25 is opened to the injection nozzle 4 configured as described above in synchronization with the weft insertion time, compressed air for conveying the weft W is supplied from the pipe 23, and weft insertion is performed.

In addition, in addition to the weft insertion period, in order to prevent mistakes in cutting the weft yarn W, or to increase weft insertion performance, in order to apply some tension to the weft yarn end remaining outside the injection nozzle after cutting, the aperture Compressed air whose flow rate has been reduced by the valve 27 is constantly supplied through the pipe 26, so that a slight breeze is constantly blowing inside the accelerating tube 11.

By the way, as a result of analyzing various causes of weft insertion errors that occur in air jet rooms equipped with such weft insertion devices, we found that the major cause of weft insertion errors is the breakage of the weft yarn W that occurs within the injection nozzle 4 during weft insertion. It has become clear that it is one of the.

In addition, the weft ends exposed to the breeze were cut off in the injection nozzle 4 at times other than the weft insertion, and the predetermined weft insertion length could not be secured during the next weft insertion, and the weft W was scheduled to be inserted. Failure to reach the desired position was also a major cause of weft insertion errors.

The causes of the weft insertion errors mentioned above are all caused by the cutting of the weft yarn W within the jet nozzle 4.

Therefore, the inventors analyzed the behavior of the weft inside the injection nozzle 4.

As a result, even though the inside of the injection nozzle 4 is a completely covered flow path, the weft W existing in the flow path
It has become clear that the weft yarn W vibrates violently and turns in the direction of untwisting, which causes the weft W to be cut within the injection nozzle 4.

The phenomenon in which the weft yarn W turns in the untwisting direction in this case is because the air flow speed is faster than the advancing speed of the weft yarn W (the weft yarn W is in a stopped state except during the weft insertion period, so the weft yarn speed is zero). It is thought that this occurs as a result of the airflow acting to squeeze the weft W.

It is thought that since the air flow acts to squeeze the weft thread W, the weft thread W is turned and is cut by the propulsive force of the air flow.

It should be noted that such a weft yarn breakage phenomenon in the injection nozzle 4 occurs due to the same cause even during weft insertion, and even when the weft yarn end is exposed to a breeze inside the injection nozzle 4 at times other than the weft insertion period.

In addition, when filament yarns are used, filament cracks are likely to occur due to intense vibration and swirling of the weft threads W within the injection nozzle 4, and even if the weft threads do not break, the weft threads W with filament cracks will be woven into the weft yarn. For,
This led to a decline in the quality of the woven fabric.

In order to eliminate these drawbacks, the applicant first installed a weft thread introducing needle installed at the rear of the nozzle body of the injection nozzle, and provided at least one point in the flow path in front of the nozzle tip to connect the flow path with the outside air. We proposed a weft insertion device equipped with a communicating exhaust hole (Japanese Patent Application No. 82897/1982).

In this device, as shown in FIG. 5, one end is open to the flow path of the nozzle body 10 and the other end is connected to the outside through an opening 28 formed in the bracket 8, and one end is an acceleration pipe. 11, and the other end is connected to the locking nut 2.
An exhaust hole 29 is provided which communicates with the outside through an opening 30 formed at the bottom.

In this device, the weft W in the flow path is drawn toward the exhaust hole 29 side by the action of the air flow flowing out from the exhaust hole 29, and moves to the inner wall side of the flow path.

The vibrations and swirling of the weft yarn W were suppressed, and the weft yarn W became almost straight, thereby eliminating weft yarn breakage within the injection nozzle.

However, in this device, when the weft yarn W is drawn to the exhaust hole 29 and moves along the inner wall of the flow path, the weft yarn W comes into contact with the open end 29a of the exhaust hole 29 on the flow path side, resulting in increased resistance and wind. There was a fear that the occurrence of cotton would increase.

Purpose This invention was made in order to eliminate the above-mentioned conventional defects.The purpose is to prevent the vibration and swirl of the weft yarn in the injection nozzle as much as possible, thereby reducing the occurrence of weft insertion errors and deterioration of woven fabric quality. An object of the present invention is to provide a weft insertion device for an air jet room, which can perform stable weft insertion and is free from the risk of increasing the resistance of the weft yarn passing through the flow path of a nozzle or increasing the occurrence of fluff. .

EXAMPLE An example embodying this invention will be described below with reference to FIG.

The injection nozzle 4 of this embodiment has basically the same construction as that shown in FIGS. 2 and 5, and the same parts are designated by the same reference numerals.

In the weft inserting device of this embodiment, as shown in FIG. The acceleration tube 11 is fixed to the bracket 8 by a screwed locking nut, and the acceleration tube 11 is press-fitted into the nozzle body 10.

The needle 16 is screwed into the housing recess 13 and fixed to the nozzle body 10 by a ring nut 31 screwed onto the outer periphery of the needle 16 .

A fitting hole 22 is formed in the upper part of the bracket 8, and communicates with the groove 17 formed on the rear outer periphery of the nozzle body 10, and into which the compressed air supply pipe 23 is fitted and secured.

A curved recess 32 is provided in the flow path 14 of the nozzle body 10, and one end of the recess 32 opens into the flow path 14 and the other end communicates with the outside via an opening 2B formed in the bracket 8. Four exhaust holes 29 are arranged in parallel.

Next, the operation of the weft insertion device constructed as described above will be explained.

After passing through the groove 17, the compressed air supplied from the pipe 23 enters the accommodation recess 13 through each air supply hole 18, and flows through the flow path 1.
4 and most of it is ejected to the outside from the tip of the accelerating tube 11.
A portion is exhausted to the outside through the exhaust hole 29.

During weft insertion, when compressed air is injected from the injection nozzle 4, the amount of air discharged from the exhaust hole 29 is very small compared to the amount of air jetted from the tip of the accelerating tube 11, and the propulsive force against the weft W is conventional. Since the apparatus is completely the same, the weft W is conveyed in the traveling direction without being affected by the exhaust air flow from the exhaust hole 29.

However, in the lateral direction, the weft W is affected by the exhaust air flow flowing out from the exhaust hole 29, so the exhaust hole 29
The weft yarn W is drawn to the side, and the entire weft W is positioned on the inner wall side of the flow path deflected in that direction and moves forward.

Therefore, the vibration and swirl of the weft yarn W are suppressed, and the weft yarn W becomes almost straight, thereby preventing the weft yarn from breaking inside the injection nozzle 4.

In the weft inserting device of this invention, the open end 29a of the exhaust hole 29 is located within the recess 32, so that the weft W is moved toward the inner wall of the flow path by the action of the airflow discharged from the exhaust hole 29. When the weft yarn W advances without contacting the opening end 29a of the exhaust hole 29 on the flow path side, the friction caused by the contact does not increase the resistance or increase the occurrence of fluff.

Furthermore, when inserting the weft yarn W into the injection nozzle 4 at the time of matching, conventionally the opening degree of the throttle valve 27 was widened and the weft yarn W was inserted into the needle 16, and when the insertion was completed, the opening degree was returned to the operating degree. However, by providing the exhaust hole 29 in the injection nozzle 4, the weft yarn W can be moved to the needle 16 while the throttle valve 27 is kept at the operating opening.
This makes it easier to insert the weft W at the time of joining.

Note that this invention is not limited to the above-mentioned embodiment, and the gist of this invention may be modified, for example, by providing the recess 32 in the acceleration tube 11 as shown in FIG. The shape of each part within the range of
It is also possible to change the configuration etc. arbitrarily.

Effects As detailed above, this invention provides a concave portion with a curved surface in at least one place in the flow path in front of the tip of the weft introducing needle installed at the rear of the nozzle main body of the injection nozzle, and the concave portion is provided with a concave portion having a curved surface. By providing an exhaust hole that communicates with the weft, vibration and swirl of the weft within the injection nozzle are suppressed, eliminating weft breakage, reducing deterioration in fabric quality, and making it possible to perform stable weft insertion. Moreover, the resistance of the weft threads passing through the flow path of the nozzle does not increase, and the generation of fluff does not increase.

In addition, it has the excellent effect of making it easier to insert the weft threads when joining.

[Brief explanation of the drawing]

Figure 1 is a plan view of the main part of the air jet room, Figure 2 is a longitudinal sectional view of a conventional injection nozzle, Figure 3 is an enlarged sectional view taken along line X-X in Figure 2, and Figure 4 is a view of the injection nozzle. FIG. 5 is a vertical sectional view showing another injection nozzle, FIG. 6 is a vertical sectional view showing an embodiment of this invention, and FIG. 7 is a modified example. It is a partially cutaway front view showing the. Gripper 2, injection nozzle 4, bracket 8, nozzle body 10, acceleration tube 11, flow path 14, exhaust hole 29, recess 32,
Weft W0

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In an air jet room for inserting weft yarns into a weft opening by jetting compressed air, at least one of the flow passages in front of the tip of a weft yarn introduction needle installed at the rear of the nozzle body of the jet nozzle. A concave portion consisting of a curved surface is provided at one location,
A weft insertion device for an air jet room, characterized in that the concave portion is provided with an exhaust hole that communicates with the flow path and the outside. 2. The weft inserting device for an air jet room according to claim 1, wherein a plurality of the exhaust holes are arranged in parallel on one side of the flow path.