JP7776255B2 - Weft tension applying device - Google Patents

Description

The present invention relates to a weft tensioning device for an air jet loom.

In order to weave high-quality fabrics using an air jet loom, it is necessary to apply appropriate tension to the inserted weft yarn and prevent it from slackening. A weft tensioning device for applying tension to the weft yarn is known, as described in Patent Document 1. The weft tensioning device described in Patent Document 1 applies tension to the weft yarn by injecting air from an air injection nozzle located at the rear of the air jet loom toward the front of the air jet loom, bending the weft yarn forward and introducing it into a stretch pipe located at the front of the air jet loom.

Japanese Patent Application Laid-Open No. 2010-285713

However, the weft tensioning device described in Patent Document 1 applies tension to the weft by bending the weft in only one direction, from the rear to the front of the air jet loom, which poses the problem of not being able to apply sufficient tension to the weft.

The present invention was made to solve the above problems, and aims to provide a weft tension applying device that is simple in configuration and can apply sufficient tension to the weft yarn.

A weft tension applying device according to the present invention is provided in an air jet loom that inserts a weft along a weft guide passage provided in the reed, the weft guide passage being provided in front of the reed at the downstream end in the weft flight direction and extending along the weft guide passage, a first air injection unit that injects air in a direction along the weft flight passage, and a second air injection unit that injects air in a direction different from the direction along the weft flight passage. The first air injection unit injects air to introduce the weft into the weft flight passage, and the second air injection unit injects air at the weft introduced into the weft flight passage between the yarn inlet and yarn outlet inside the weft flight passage.

The weft passage may have a bent portion that protrudes from the rear side to the front side of the air jet loom between the yarn inlet and the yarn outlet .
The second air injection section may inject air at the bent portion.
The first air injection unit may stop injecting air after the second air injection unit has injected air.
Furthermore, the first air injection unit may continue to inject air after the second air injection unit has injected air.

With the weft tension applying device of the present invention, the first air injection unit injects air in a direction along the weft flight path to introduce the weft into the weft flight path, and the second air injection unit injects air in a direction different from the weft flight path at the weft introduced into the weft flight path, making it possible to apply sufficient tension to the weft with a simple configuration.

1 is a perspective view showing an outline of a loom according to an embodiment of the present invention; FIG. 2 is a right side view showing the weft guide passage shown in FIG. 1 . FIG. 2 is a plan view showing an outline of the loom shown in FIG. 1 . FIG. 2 is a perspective view of the stretching mechanism shown in FIG. 1. FIG. 4 is a bottom view of the stretching mechanism shown in FIG. 3 . FIG. 4 is a plan end view of the upper portion of the stretching mechanism shown in FIG. 3. 1 is a front end view of the upper part of the stretching mechanism showing the operation of the mechanism according to an embodiment of the present invention. FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Fig. 1 is a perspective view showing an outline of a loom according to an embodiment of the present invention, illustrating the configuration of the right end of the air jet loom. Fig. 2 is a right side view showing the weft guide passage shown in Fig. 1. A modified reed 10 is provided above a slay 13 extending in the direction of travel of the weft in the air jet loom. The modified reed 10 is formed to extend in the direction of travel of the weft, and a weft guide passage 11 through which the weft travels is formed on its front surface. The weft travels through the weft guide passage 11 from upstream to downstream along the air flow due to the air injection action of main and sub-nozzles for weft insertion (not shown). The modified reed 10 constitutes a reed.

A stretching mechanism 40 is provided in front of the modified reed 10, i.e., the front of the air jet loom, to apply appropriate tension to the weft yarn and prevent it from slackening. A rectangular tubular weft passage 50 is formed in the upper mechanism 41 of the stretching mechanism 40. The weft passage 50 is disposed in the weft guide passage 11 and extends along it. The weft passage 50 has a yarn inlet 51 on the upstream side through which the weft yarn is introduced, and a yarn outlet 52 on the downstream side through which the weft yarn is discharged. Therefore, the weft yarn traveling through the weft guide passage 11 of the modified reed 10 can travel through the weft passage 50. The stretching mechanism 40 is made of an appropriate material, such as resin or metal. The stretching mechanism 40 constitutes a weft tension applying device.

The upper part 41 of the stretching mechanism 40 has a protrusion 42 that protrudes from the main body of the stretching mechanism 40 toward the front of the air jet loom. To the left of the protrusion 42 when viewed from the front of the air jet loom, i.e., upstream in the weft yarn flying direction, is an air blow hole 60 for blowing air onto the weft yarn in the weft yarn flying passage 50. An air blow hose 62 is connected to the air blow hole 60 via an air blow coupling 61. The air blow hose 62 is connected to an air supply source (not shown) in the factory via a well-known air valve (not shown).

The lower mechanism portion 43 of the stretch mechanism 40 is formed with a stretch air hole 70 for spraying stretch air onto the weft yarn in the weft yarn flight passage 50. A stretch air hose 72 is connected to the stretch air hole 70 via a stretch air coupling 71. The stretch air hose 72 is connected to an air supply source (not shown) in the factory via a well-known air valve (not shown). The air jet loom is also equipped with a control device (not shown) that controls the supply of air to the air blow hole 60 and the stretch air hole 70.

Figure 3 is a plan view showing the outline of the loom shown in Figure 1, showing the modified reed 10 and stretching mechanism 40 in a horizontal cross-sectional view along the weft guide passage 11. The modified reed 10 has multiple reed dents 12 arranged at equal intervals perpendicular to the weft travel direction. Between each reed dent 12, warp threads 21, which together with the weft thread 23 form the woven fabric 31, and selvedge threads 22, which together with the weft thread 23 form the waste selvedge 32, pass. The weft thread 23 travels through the weft guide passage 11 of the modified reed 10 and the weft travel passage 50 located within the weft guide passage 11. A well-known optical weft detector 14 is provided on the right side of the stretching mechanism 40 when viewed from the front of the air jet loom, i.e., downstream in the weft travel direction, to detect long picks and break-outs of the weft thread 23.

Figure 4 is a perspective view of the stretch mechanism shown in Figure 1. As shown in Figure 4, the air blow hole 60 of the stretch mechanism 40 opens on the left side of the protrusion 42 of the stretch mechanism 40. Meanwhile, an air vent hole 53 opens on the top surface of the weft yarn passage 50. The air vent hole 53 is connected to the weft yarn passage 50. The stretch mechanism 40 has a stretch air passage 73 extending vertically inside. The weft yarn passage 50 is connected to the stretch air passage 73. The stretch air passage 73 is connected to the stretch air hole 70 of the mechanism lower part 43. Therefore, the stretch air hole 70 is configured to communicate with the air vent hole 53 via the stretch air passage 73 and the weft yarn passage 50. Figure 5 is a bottom view of the stretch mechanism shown in Figure 3. As shown in Figure 5, the stretch air hole 70 opens in the center of the bottom surface of the mechanism lower part 43.

Figure 6 is a plan end view of the upper part of the stretching mechanism shown in Figure 3. As shown in Figure 6, the weft passage 50 of the stretching mechanism 40 has a bent portion 54 located inside the passage near the protruding portion 42 between the yarn inlet 51 and the yarn outlet 52. The bent portion 54 is trapezoidally shaped so as to protrude from the rear to the front of the air jet loom. Here, if the width of the weft passage 50 is the horizontal width along the front-to-rear direction of the air jet loom, the width of the weft passage 50 at the bent portion 54 is narrower than the width of the weft passage 50 at the yarn inlet 51 and the yarn outlet 52. As a result, the weft passage 50 is formed so that its centerline bends toward the front of the air jet loom at the bent portion 54.

At the bend 54, a stretch air outlet 74 connected to the stretch air passage 73 (see Figure 4) opens substantially vertically upward at the narrowest part of the weft yarn passage 50. That is, the stretch air hole 70 communicates with the stretch air outlet 74 via the stretch air passage 73. The stretch air outlet 74 and the air vent hole 53 open so that they substantially overlap when viewed vertically. The stretch air outlet 74 constitutes a second air injection section.

An air blow nozzle 63 having an air blow hole 60 as an air inlet is formed in the protruding portion 42. The air blow nozzle 63 extends along the inner wall of the weft yarn passage 50 between the bent portion 54 and the yarn outlet 52, to the area between the bent portion 54 and the yarn outlet 52. The air blow nozzle 63 has an air blow outlet 64 at its tip. The air blow outlet 64 opens to the right of the bent portion 54, i.e., on the yarn outlet 52 side, between the bent portion 54 and the yarn outlet 52, of the weft yarn passage 50. The air blow outlet 64 also has a gap between it and the inner wall between the bent portion 54 and the yarn outlet 52, allowing the weft yarn 23 to pass through this gap. The air blow nozzle 63 constitutes a first air injection unit.

Next, the operation of the stretching mechanism 40 in this embodiment will be described.
3, during insertion of the weft yarn 23, the action of the air jetted from the main jet nozzle and the sub-jet nozzle causes the weft yarn 23 to travel through the weft guide passage 11 of the modified reed 10 from the left side to the right side of the loom, i.e., from upstream to downstream of the air flow from the main nozzle. After the weft yarn 23 has traveled to the position of the selvage yarn 22, the weft yarn 23 is introduced into the weft traveling passage 50 of the stretching mechanism 40 through the yarn inlet 51.

As shown in Figure 4, when the weft yarn 23 is introduced from the yarn inlet 51 in the direction of arrow A, the air valve is opened by the control device, and air is supplied from the air supply source to the air blow hole 60 in the direction of arrow F via the air blow hose 62 (see Figure 3).

Air supplied to the air blow hole 60 in the direction of arrow F is sprayed in the direction of arrow G from the air blow nozzle 64 at the tip of the air blow nozzle 63, as shown in Figure 6. That is, the air blow nozzle 63 sprays air in a direction along the weft yarn flight path 50, or more specifically, in a direction along the inner wall between the bent portion 54 and the yarn outlet 52. This air blow causes the weft yarn 23 to be sucked in the direction of arrow B, toward the yarn outlet 52, when it is introduced into the yarn inlet 51. This allows the weft yarn 23 to be introduced smoothly into the yarn inlet 51.

Next, the weft yarn 23 travels in the direction of arrow B while bending toward the front of the air jet loom at the bending portion 54. Therefore, the weft yarn 23 travels while making contact with the bending portion 54. A first tension is applied to the weft yarn 23 due to the bending at the bending portion 54 and the friction with the bending portion 54 caused by the contact. After the tip of the weft yarn 23 passes through the bending portion 54 and is led out of the yarn outlet 52, the air valve is opened by the control device, and stretch air is supplied from the air supply source via the stretch air hose 72 (see FIG. 3) to the stretch air hole 70 shown in FIG. 4 in the direction of arrow C. The stretch air supplied to the stretch air hole 70 flows upward through the stretch air passage 73 in the direction of arrow D. The stretch air is then sprayed approximately vertically upward from the stretch air nozzle 74 shown in FIG. 6. In other words, the stretch air nozzle 74 sprays stretch air in a direction different from the direction along the weft yarn travel passage 50.

The timing for injecting this stretch air is preferably when the weft yarn 23 has flown and is fully stretched. The stretch air then flows out mainly from the air vent holes 53 (see Figure 4) above the weft yarn passage 50.

At the bend 54, the weft yarn 23 receives stretch air from the stretch air nozzle 74 in a generally vertically upward direction, different from the direction along the weft yarn flight path 50. As a result, as shown in Figure 7, the weft yarn 23 bends in the generally vertically upward direction indicated by arrow H and is pressed against the upper surface of the inner wall of the bend 54 and the corner 53a of the air vent hole 53. Therefore, a second tension is applied to the weft yarn 23 due to friction between the weft yarn 23 and the upper surface of the inner wall of the bend 54 and between the weft yarn 23 and the corner 53a of the air vent hole 53.

A strong tension can be applied to the weft thread 23 by applying a first tension to the weft thread 23 as it bends and flies due to the bending portion 54, and by applying a second tension to the weft thread 23 as the stretch air presses the weft thread 23 in the direction of arrow H. This reduces slack in the weft thread 23 and improves weaving quality compared to when only one of the first tension and second tension is applied to the weft thread 23.

After the stretch air is sprayed from the stretch air nozzle 74, the control device stops the supply of air to the air blow hole 60. This stops the air blow from the air blow nozzle 64. This reduces air consumption and reduces the cost of the weaving process.

Another method of applying tension to the weft yarn 23 is to blow more powerful air from the air blow nozzle 63 shown in Figure 6 in a direction along the weft yarn flight path 50. However, if a covering yarn is used for the weft yarn 23, the cover yarn of the weft yarn 23 may separate and fly ahead, leading to its exit from the yarn outlet 52. As a result, as shown in Figure 3, the weft detector 14 for the weft yarn 23, located to the right of the stretch mechanism 40, may detect the separated cover yarn, potentially resulting in excessive detection of long picks and blowouts. This method therefore results in unnecessary stoppages in the weaving process, potentially increasing weaving costs.

On the other hand, in this embodiment, the air blow nozzle 63 does not blow strong air in the direction along the weft yarn flight path 50, so even if a covering yarn is used for the weft yarn 23, separation of the covering yarn is suppressed. This reduces the probability of unnecessary stoppages in the weaving process.

In addition, some weft tensioning devices for air jet looms apply tension to the weft by bending the weft toward the rear of the air jet loom, i.e., toward the back of the reed. However, with such weft tensioning devices, bending the weft toward the back of the reed causes the warp to be pulled by the weft and bend toward the back of the reed, forcing the reed dents to move aside, which can damage reeds, especially those with high-density dents.

On the other hand, in this embodiment, the air blow nozzle 63 injects air in a direction along the weft yarn passage 50, and the stretch air injection port 74 injects air in the direction of arrow H, which is approximately vertically upward, onto the weft yarn introduced into the weft yarn passage 50. As a result, the yarn does not push aside the dents of the modified reed 10, preventing damage to the modified reed 10.

As such, the stretching mechanism 40 of this embodiment is provided in front of the modified reed 10 of an air jet loom that inserts the weft 23 along the weft guide passage 11 provided in the modified reed 10, and includes a weft passage 50 extending along the weft guide passage 11, an air blow nozzle 63 that sprays air in a direction along the weft passage 50, and a stretch air nozzle 74 that sprays air in a direction different from the direction along the weft passage 50. The air blow nozzle 63 sprays air to introduce the weft 23 into the weft passage 50, and the stretch air nozzle 74 sprays air at the weft 23 introduced into the weft passage 50, so that a sufficient amount of tension can be applied to the weft 23 with a simple configuration.

In addition, with the stretching mechanism 40 according to this embodiment, the weft thread passage 50 has a bent portion 54, which allows strong tension to be applied to the weft thread 23 due to friction between the weft thread 23 and the bent portion 54.

Furthermore, with the stretching mechanism 40 according to this embodiment, the stretch air nozzle 74 injects air at the bent portion 54. As a result, the weft yarn 23, which is bent toward the front of the air jet loom at the bent portion 54, bends in the direction of arrow H, which is approximately vertically upward, and is pressed against the upper surface of the inner wall of the bent portion 54 and the corner 53a of the air vent hole 53, generating a large frictional force. This allows even greater tension to be applied to the weft yarn 23.

Furthermore, with the stretching mechanism 40 according to this embodiment, the air blow nozzle 63 stops spraying air after the stretching air outlet 74 has sprayed air, thereby reducing air consumption and reducing the cost of the weaving process.

In this embodiment, the air blow nozzle 63 stops blowing air after the stretch air outlet 74 injects air. However, if the weft yarn 23 is a yarn that is difficult to separate, such as a filament yarn, air blowing from the air blow nozzle 63 may continue after the stretch air outlet 74 injects air.

In this way, with the stretching mechanism 40 according to this embodiment, the air blow nozzle 63 continues to inject air after the stretching air injection port 74 has injected air. Therefore, in addition to the first and second tensions described above, a third tension is applied to the weft yarn 23 by blowing air in the direction of the weft yarn flight path 50, thereby applying a stronger tension to the weft yarn 23.

In addition, in order to increase the amount of stretch of the flying weft yarn 23 and to extend the time the weft yarn 23 is fully stretched, air blowing from the air blow nozzle 63 may be continued after air is sprayed from the stretch air nozzle 74. Furthermore, an additional air blow nozzle may be provided at a position different from the air blow nozzle 63 to perform additional air blowing.

In addition, while the stretch air outlet 74 is shown opening substantially vertically upward, it may also open in any other direction as long as it is different from the air blow direction of the air blow nozzle 63. For example, the stretch air outlet 74 may open toward the front of the air jet loom, i.e., away from the modified reed 10. As a result, similar to this embodiment, the stretch mechanism 40 can inject stretch air in a direction different from the direction along the flight path of the weft yarn 23, thereby applying tension to the weft yarn 23.

10: Deformed reed (reed), 11: Weft guide passage, 23: Weft, 40: Stretching mechanism (weft tensioning device), 50: Weft flight passage, 54: Bending section, 63: Air blow nozzle (first air injection section), 74: Stretch air injection port (second air injection section).

Claims (5)

1. A weft tensioning device for an air jet loom that inserts a weft along a weft guide passage provided in a reed, the weft tensioning device being provided in front of the reed at a downstream end of the reed in a direction in which the weft travels ,
a weft running passage extending along the weft guide passage;
a first air injection unit that injects air in a direction along the weft flying path;
a second air injection unit that injects air in a direction different from the direction along the weft flying path,
the first air injection unit injects air to introduce the weft into the weft flying passage,
The second air injection unit is a weft tension imparting device that injects air onto the weft introduced into the weft flying passage between a yarn inlet and a yarn outlet inside the weft flying passage. 2. The weft tension applying device according to claim 1, wherein the weft passage has a bent portion that protrudes from the rear side to the front side of the air jet loom between the yarn inlet and the yarn outlet . A weft tension applying device according to claim 2, wherein the second air injection unit injects air at the bent portion. A weft tension applying device according to any one of claims 1 to 3, wherein the first air injection unit stops injecting air after the second air injection unit has injected air. A weft tension applying device according to any one of claims 1 to 3, wherein the first air injection unit continues to inject air after the second air injection unit has finished injecting air.