EP4261332A1

EP4261332A1 - Air jet loom with weft yarn tensioning device

Info

Publication number: EP4261332A1
Application number: EP23164004.6A
Authority: EP
Inventors: Daisuke Yagi; Hikaru Maeda
Original assignee: Toyota Industries Corp
Current assignee: Toyota Industries Corp
Priority date: 2022-04-13
Filing date: 2023-03-24
Publication date: 2023-10-18
Also published as: JP2023156763A; CN116905163A

Abstract

A weft yarn tensioning device (40) for an air jet loom (10) includes: a passage forming member (41); an air discharge portion (42); and a shielding member (46) covering a dent gap (S) formed between dents (15) adjacent to each other in a weft insertion direction (X), from a rear surface side of dents (15). In a front view of the air jet loom (10), the shielding member (46) covers at least a part of the dent gap (S) in which a warp yarn (52) is not inserted among dent gaps (S) existing from a downstream side of a weft yarn detection device (20) in the weft insertion direction (X) and from an upstream side of a yarn inlet (44a) of a weft yarn travel passage (44) in the weft insertion direction (X) to the yarn inlet (44a), from the rear surface side of the dents (15).

Description

BACKGROUND ART

The present invention relates to a weft yarn tensioning device for an air jet loom.
In an air jet loom, a weft yarn is inserted along a weft yarn guide passage disposed in front of a reed. The weft yarn travels through the weft yarn guide passage from an upstream side to a downstream side thereof along a flow of air discharged from an air nozzle. In order to produce a high-quality woven fabric, an air jet loom needs to be configured to suppress loosening of a weft yarn by applying an adequate tension to the traveling weft yarn. As a weft yarn tensioning device for applying a tension to a weft yarn, a weft yarn tensioning device disclosed in Japanese Patent Application Publication No. 2022-014545 has been known.
The weft yarn tensioning device disclosed in Japanese Patent Application Publication No. 2022-014545 includes a weft yarn travel passage extending along a weft yarn guide passage, an air blow nozzle from which air is discharged in a direction along the weft yarn travel passage, and a stretch air discharge port from which air is discharged in a direction different from the direction along the weft yarn travel passage.
The air is discharged from air blow nozzle so that a weft yarn is introduced into the weft yarn travel passage. The air is discharged from the stretch air discharge port to the weft yarn introduced into the weft yarn travel passage. Due to the air discharged from the stretch air discharge port, a sufficient tension is applied to the weft yarn introduced into the weft yarn travel passage.
When the weft yarn having traveled through the weft yarn guide passage travels near a rear side of a reed in the weft yarn guide passage along a flow of the discharged air, the weft yarn comes in contact with a part of the weft yarn travel passage surrounding a yarn inlet. As a result, the weft yarn may fail to be introduced smoothly into the weft yarn travel passage.

SUMMARY

In accordance with an aspect of the present invention, there is provided a weft yarn tensioning device for an air jet loom in which a weft yarn is inserted along a weft yarn guide passage formed in a reed and a plurality of dents are arranged in a weft insertion direction of the weft yarn. The air jet loom includes a weft yarn detection device configured to detect the weft yarn traveling through the weft yarn guide passage. The weft yarn tensioning device is disposed at a position close to a leading end of the weft yarn inserted into the weft yarn guide passage and on a downstream side of the weft yarn detection device in the weft insertion direction, configured to catch the leading end of the weft yarn, and apply a tension to the weft yarn. The weft yarn tensioning device includes: a passage forming member defining a weft yarn travel passage extending along the weft yarn guide passage in the weft yarn guide passage; an air discharge portion from which air is discharged to the weft yarn travel passage so that the leading end of the weft yarn is caught inside the passage forming member; and a shielding member covering a dent gap formed between the dents adjacent to each other in the weft insertion direction, from a rear surface side of the dents. In a front view of the air jet loom, the shielding member covers at least a part of the dent gap in which a warp yarn is not inserted among dent gaps existing from a downstream side of the weft yarn detection device in the weft insertion direction and from an upstream side of a yarn inlet of the weft yarn travel passage in the weft insertion direction to the yarn inlet, from the rear surface side of the dents.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the embodiments together with the accompanying drawings in which:

FIG. 1 is a perspective view, schematically illustrating a weft yarn tensioning device for an air jet loom;
FIG. 2 is a partial front view of the weft yarn tensioning device;
FIG. 3 is a side view of a dent and a vibration suppressing member serving as a shielding member;
FIG. 4 is a perspective view of the vibration suppressing member;
FIG. 5 is a partial side view of a yarn inlet of a weft yarn travel passage;
FIG. 6 is a partial front view of a shielded area and the weft yarn tensioning device;
FIG. 7 is a cross-sectional plan view of the weft yarn tensioning device;
FIG. 8 is a side view of a shielding member according to a modified embodiment; and
FIG. 9 is a cross-sectional plan view for an air jet loom according to a modified embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The following will describe an embodiment of a weft yarn tensioning device for an air jet loom with reference to FIG. 1 to FIG. 7.

Air Jet Loom

As illustrated in FIG. 1 and FIG. 2, an air jet loom 10 includes a main nozzle 11 and a sub nozzle 12, a reed 13, a sley 14, a weft yarn detection device 20, a vibration suppressing member 30, a weft yarn tensioning device 40, and a shielding member 46. The weft yarn 51 travels in a longitudinal direction of the sley 14. A direction in which the weft yarn 51 travels is referred to as a weft insertion direction X. An upstream side in the weft insertion direction X corresponds to a side of a start of weft insertion of the weft yarn 51, and a downstream side in the weft insertion direction X corresponds to a travel direction of the weft yarn 51.

Main Nozzle and Sub Nozzle

The reed 13 includes a weft yarn guide passage 17 extending in the weft insertion direction X. The main nozzle 11 is fixed to the sley 14 on an upstream side in the weft insertion direction X. The main nozzle 11 is configured such that the weft yarn 51 is inserted along the weft yarn guide passage 17. The main nozzle 11 is fixed to the sley 14 such that a position of the main nozzle 11 is adjustable.
The sub nozzle 12 is fixed to the sley 14. Air is discharged from the sub nozzle 12 toward the weft yarn guide passage 17. The air is discharged from the sub nozzle 12 in a direction along the weft insertion direction X. The weft yarn 51 receives the air discharged from the main nozzle 11 and the sub nozzle 12, and thus travels through the weft yarn guide passage 17 in the weft insertion direction X.

Reed

The reed 13 includes a plurality of dents 15 and a holding member 16 holding the plurality of dents 15. In the air jet loom 10, the plurality of dents 15 are arranged side by side in the weft insertion direction X of the weft yarn 51. Dent gaps S are each formed between any two of the dents 15 adjacent to each other in the weft insertion direction X. The dent gaps S are gaps in which warp yarns 52 are inserted, respectively. However, the warp yarns 52 are not inserted in the dent gaps S at positions of the weft yarn detection device 20 and the weft yarn tensioning device 40 which will be described below.
As illustrated in FIG. 3, each of the dents 15 has a recess 15a. A front surface of each of the dents 15 is recessed toward a rear surface of each of the dents 15 to form the recess 15a. Each of the dents 15 has a first edge 15b, a second edge 15c, and a third edge 15d which define the recess 15a. The first edge 15b is closest to the rear surface of each of the dents 15, as viewed in the weft insertion direction X. The first edge 15b extends in an up-down direction of each of the dents 15. The second edge 15c extends from an upper end of the first edge 15b toward the front surface of each of the dents 15. The second edge 15c extends in a front-rear direction of each of the dents 15. The third edge 15d extends from a lower end of the first edge 15b toward the front surface of each of the dents 15. The third edge 15d extends in the front-rear direction of each of the dents 15. A "part of each of the dents 15 close to the rear surface thereof" corresponds to a part of each of the dents 15 close to the first edge 15b, among parts of each of the dents 15 along the first edge 15b, the second edge 15c, and the third edge 15d. The weft yarn guide passage 17 is formed by recesses 15a of all the dents 15 arranged in the weft insertion direction X.
As illustrated in FIG. 1, the warp yarns 52 are inserted in gaps, respectively, each formed between any two of the dents 15 adjacent to each other in the weft insertion direction X, i.e., are inserted in the dent gaps S, respectively. In the air jet loom 10, a woven fabric 50 is produced by the weft yarns 51 and the warp yarns 52. Selvage yarns 54 are inserted in the dent gaps S, respectively, on a downstream side of the weft yarn detection device 20 in the weft insertion direction X and on an upstream side of the weft yarn tensioning device 40 in the weft insertion direction X. The selvage yarns 54 and the weft yarns 51 form selvages 53.

Weft Yarn Detection Device

The weft yarn detection device 20 detects the weft yarn 51 traveling through the weft yarn guide passage 17. The weft yarn detection device 20 is disposed on an upstream side of the selvage yarns 54 of the selvages 53 in the weft insertion direction X of the weft yarn 51. Here, a view of the air jet loom 10 seen from the front is referred to as a front view of the air jet loom 10. The front view of the air jet loom 10 corresponds to a front view of the dents 15. In the front view of the air jet loom 10, the weft yarn detection device 20 is disposed on the upstream side of the selvage yarns 54 of the selvages 53 in the weft insertion direction X.
As illustrated in FIG. 2, the weft yarn detection device 20 includes a device body 23, a light-emitting portion 21, a light-receiving portion 22, and a control device (not illustrated) built in the device body 23. The light-emitting portion 21 and the light-receiving portion 22 are positioned at an upper end of the device body 23. The light-emitting portion 21 and the light-receiving portion 22 are connected to the control device (not illustrated) through signals.
The light-emitting portion 21 emits a light toward the weft yarn 51 having been inserted along the weft yarn guide passage 17. The light-receiving portion 22 receives the light reflected on the weft yarn 51 or the dents 15. For example, when the weft yarn 51 reaches a light-emitting area of the light-emitting portion 21, the light-receiving portion 22 receives the reflected light from the weft yarn 51. The control device converts the received light into an electrical signal. The control device outputs the electric signal into a main control unit (not illustrated). A range in which the weft yarn detection device 20 detects the weft yarn 51 is the same as a dimension of the device body 23 in the weft insertion direction X.

Vibration Suppressing Member

As illustrated in FIG. 3 and FIG. 4, the vibration suppressing member 30 comes in contact with the rear surfaces of the dents 15 to suppress vibration of the dents 15. The vibration suppressing member 30 includes a mounting portion 31 and an anti-vibration member 33. The mounting portion 31 has a long plate shape. The mounting portion 31 has a first surface 31a and a second surface 31b on opposite end surfaces of the mounting portion 31 in a plate thickness direction thereof. The anti-vibration member 33 is mounted to the reed 13 by the mounting portion 31.
The mounting portion 31 has a hook portion 32 at an upper end of the mounting portion 31. The hook portion 32 is curved to overlap with the first surface 31a of the mounting portion 31. The hook portion 32 is hooked onto the holding member 16 of the reed 13 from above. The hook portion 32 is fixed to the holding member 16 with bolts 34. Thus, the vibration suppressing member 30 is mounted to the reed 13.
The anti-vibration member 33 is mounted to the first surface 31a of the mounting portion 31. The anti-vibration member 33 is provided over an area from the vicinity of a central portion of the mounting portion 31 in a long-side direction thereof to a lower end of the mounting portion 31. The anti-vibration member 33 is made of an elastic member such as a rubber.
The anti-vibration member 33 has a first surface 33a and a second surface 33b on opposite end surfaces of the anti-vibration member 33 in a thickness direction thereof. A direction in which a short side of each of the first surface 33a and the second surface 33b extends is referred to as a short-side direction of the anti-vibration member 33. A direction in which a long side of each of the first surface 33a and the second surface 33b extends is referred to as a long-side direction of the anti-vibration member 33. The short-side direction of the anti-vibration member 33 corresponds to the weft insertion direction X. The long-side direction of the anti-vibration member 33 corresponds to the up-down direction of the dents 15. The anti-vibration member 33 has a first side surface 33c and a second side surface 33d on opposite end surfaces of the anti-vibration member 33 in the short-side direction thereof.
The first surface 33a of the anti-vibration member 33 is joined to the first surface 31a of the mounting portion 31. The second surface 33b of the anti-vibration member 33 is pressed against the rear surfaces of the dents 15. That is, a front surface of the anti-vibration member 33 is in contact with the rear surfaces of the dents 15. The vibration of the dents 15 is absorbed by the anti-vibration member 33 at a time of a beating operation. That is, the anti-vibration member 33 suppresses the vibration of the dents 15. The anti-vibration member 33 suppresses the vibration of the dents 15, which prevents deterioration in accuracy of detection of the weft yarn 51 by the weft yarn detection device 20 due to the vibration of the dents 15. The anti-vibration member 33 is attached to the dents 15 to face the light-emitting portion 21 and the light-receiving portion 22 of the weft yarn detection device 20 in the front-rear direction of the dents 15.

Weft Yarn Tensioning Device

As illustrated in FIG. 1, the weft yarn tensioning device 40 catches a leading end of the weft yarn 51 and applies a tension to the weft yarn 51. The weft yarn tensioning device 40 suppresses loosening of the weft yarn 51 by applying an adequate tension to the weft yarn 51.
The weft yarn tensioning device 40 is disposed in front of the reed 13, at a position close to the leading end of the weft yarn 51 inserted into the weft yarn guide passage 17, on a downstream side of the weft yarn detection device 20 in the weft insertion direction X of the weft yarn 51. Specifically, the weft yarn tensioning device 40 is disposed at a position close to the leading end of the weft yarn 51 inserted into the weft yarn guide passage 17, on the downstream side of the selvage yarns 54 of the selvages 53 in the weft insertion direction X of the weft yarn 51.
As illustrated in FIGS. 2, 5, 6, and 7, the weft yarn tensioning device 40 includes a passage forming member 41, an air discharge portion 42, and the shielding member 46. The passage forming member 41 has a long cylindrical shape. The passage forming member 41 is integrated with an upper end portion of the air discharge portion 42. The passage forming member 41 is disposed in the weft yarn guide passage 17. A central axis of the passage forming member 41 extends in the weft insertion direction X. The passage forming member 41 is formed over the plurality of dents 15.
A rear surface of the passage forming member 41 is provided along the first edge 15b of each of the dents 15. An upper surface of the passage forming member 41 is provided along the second edge 15c of each of the dents 15. A lower surface of the passage forming member 41 is provided along the third edge 15d of each of the dents 15.
A weft yarn travel passage 44 is formed in the passage forming member 41. Thus, the weft yarn travel passage 44 extending along the weft yarn guide passage 17 is defined by the passage forming member 41 in the weft yarn guide passage 17. A yarn inlet 44a of the weft yarn travel passage 44 is opened on the upstream side in the weft insertion direction X in the passage forming member 41. The weft yarn 51 is introduced from the yarn inlet 44a into the weft yarn travel passage 44. In the passage forming member 41, a yarn outlet 44b of the weft yarn travel passage 44 is opened on a downstream side in the weft insertion direction X. The weft yarn travel passage 44 extends along the weft insertion direction X. As a result, air is discharged from the main nozzle 11 and the sub nozzle 12 in a direction along the weft yarn travel passage 44.
As illustrated in FIG. 5, the yarn inlet 44a has first to fourth opening edges 45a to 45d. The first opening edge 45a extends along the first edge 15b of the recess 15a in the up-down direction of the dent 15. The second opening edge 45b extends from an upper end of the first opening edge 45a along the second edge 15c of the recess 15a in the front-rear direction of the dent 15. The third opening edge 45c extends from a lower end of the first opening edge 45a along the third edge 15d of the recess 15a in the front-rear direction of the dent 15. The fourth opening edge 45d extends in an arc shape to connect the second opening edge 45b and the third opening edge 45c. A part of the passage forming member 41 along the first to fourth opening edges 45a to 45d corresponds to a part of the weft yarn travel passage 44 surrounding the yarn inlet 44a. A part of the dent 15 along the first to third edges 15b to 15d also corresponds to the part of the weft yarn travel passage 44 surrounding the yarn inlet 44a.
As illustrated in FIG. 6 and FIG. 7, the weft yarn 51 travels through the weft yarn guide passage 17, and then travels through the weft yarn travel passage 44. Air is discharged from the air discharge portion 42 to the weft yarn travel passage 44 so that the leading end of the weft yarn 51 is caught inside the passage forming member 41. The air is discharged into the passage forming member 41, which applies a tension to the weft yarn 51.

Shielding Member

The shielding member 46 suppresses leakage of air through gaps each formed between any two of the dents 15 adjacent to each other in the weft insertion direction X. The shielding member 46 also functions as the vibration suppressing member 30. The vibration suppressing member 30 facing the weft yarn detection device 20 is referred to as a first vibration suppressing member 301. The vibration suppressing member 30 disposed near the yarn inlet 44a of the weft yarn travel passage 44 is referred to as a second vibration suppressing member 302. That is, the shielding member 46 also functions as the second vibration suppressing member 302. Thus, the shielding member 46 includes the mounting portion 31 and the anti-vibration member 33.
The shielding member 46 is disposed near the weft yarn tensioning device 40. A part of the shielding member 46 close to the second side surface 33d of the anti-vibration member 33 overlaps with the passage forming member 41 in the front-rear direction of the dents 15. Therefore, the second side surface 33d of the anti-vibration member 33 is disposed on the downstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X.
In the shielding member 46, the first side surface 33c of the anti-vibration member 33 is disposed on the downstream side of the selvage yarns 54 of the selvages 53 in the weft insertion direction X. One of the selvage yarns 54 of the selvages 53 on the most downstream side in the weft insertion direction X is referred to as an end selvage yarn 54a. The shielding member 46 is disposed in an area from a position on the downstream side of the end selvage yarn 54a in the weft insertion direction X to a position on the downstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X. That is, in the front view of the air jet loom 10, the shielding member 46 is disposed in an area from the downstream side of the selvage yarns 54 in the weft insertion direction X and from the upstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X, to the yarn inlet 44a.
The shielding member 46 covers the dents 15 arranged in the weft insertion direction X, from the rear surface side of the dents 15. Thus, the shielding member 46 covers the dent gaps S each formed between the dents 15 adjacent to each other in the weft insertion direction X, from the rear surface side of the dents 15. In the front view of the air jet loom 10, the shielding member 46 covers the plurality of dent gaps S existing from the downstream side of the weft yarn detection device 20 in the weft insertion direction X and from the upstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X, to the yarn inlet 44a. The shielding member 46 covers the dent gaps S in which the warp yarns 52 are not inserted, respectively, from the rear surface side of the dents 15.
In the front view of the air jet loom 10, a downstream end of the weft yarn detection device 20 in the weft insertion direction X corresponds to a downstream end within a detection area of the weft yarn 51 detected by the weft yarn detection device 20. In the front view of the airjet loom 10, the shielding member 46 covers the dent gaps S existing from the downstream side of the downstream end within the detection area of the weft yarn 51 detected by the weft yarn detection device 20 and from the upstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X, to the yarn inlet 44a. It can be said that the shielding member 46 covers the dent gaps S in which the warp yarns 52 are not inserted, respectively, from the rear surface side of the dents 15.
The dent gaps S covered by the shielding member 46 correspond to the dent gaps S in which the selvage yarns 54, i.e., the warp yarns 52 are not inserted, respectively. In the front view of the air jet loom 10, the shielding member 46 covers the dent gaps S existing from the downstream side of the selvage yarns 54 in the weft insertion direction X and from the upstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X, to the yarn inlet 44a. The shielding member 46 covers the dent gaps S from the rear surface side of the dents 15. A part of the reed 13 covered by the anti-vibration member 33 from the rear surface side of the dents 15 is referred to as a shielded area R.
The first side surface 33c of the anti-vibration member 33 corresponds to an upstream end of the shielding member 46 in the weft insertion direction X. The second side surface 33d of the anti-vibration member 33 corresponds to a downstream end of the shielding member 46 in the weft insertion direction X. Thus, the second side surface 33d positioned at the downstream end of the shielding member 46 is positioned on the downstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X.
In the shielding member 46, the second surface 33b of the anti-vibration member 33 is in contact with rear surfaces of all the dents 15 arranged in the shielded area R. That is, the front surface of the shielding member 46 is in contact with the rear surfaces of the dents 15. The anti-vibration member 33 is in contact with the rear surfaces of the dents 15 in an area from an upper side of the recess 15a to the recess 15a and a lower side of the recess 15a. Thus, the shielding member 46 covers a part of the dent gaps S extending along the entire weft yarn guide passage 17 in the up-down direction of the weft yarn guide passage 17 from the rear surface side of the dents 15 and covers a part of the dent gaps S extending downward lower than the third edge 15d corresponding to the lower end of the weft yarn guide passage 17 from the rear surface side of the dents 15. That is, the shielding member 46 covers a part of the dent gaps S from the rear surface side of the dents 15.

Operation of Embodiment

In the air jet loom 10, at a time of weft insertion of the weft yarn 51, the air is discharged from the main nozzle 11 and the sub nozzle 12, so that the weft yarn 51 travels through the weft yarn guide passage 17 in the weft insertion direction X. After the weft yarn 51 travels and reaches the weft yarn detection device 20, the weft yarn 51 travels toward the weft yarn travel passage 44 of the weft yarn tensioning device 40 on the downstream side of the weft yarn detection device 20 in the weft insertion direction X, specifically on the downstream side of the selvage yarns 54 in the weft insertion direction X.
The shielding member 46 covers the dent gaps S near the yarn inlet 44a of the weft yarn travel passage 44 from the rear surface side of the dents 15, which suppresses leakage of the air toward the rear surfaces of the dents 15. As a result, when the weft yarn 51 travels near the yarn inlet 44a of the weft yarn travel passage 44, the weft yarn 51 is prevented from traveling so as to approach the rear surfaces of the dents 15 due to the leakage of the air toward the rear surface side of the dents 15. This suppresses a contact of the weft yarn 51 with a part of the weft yarn travel passage 44 surrounding the yarn inlet 44a, particularly, suppresses a contact of the weft yarn 51 with a part of each of the dents 15 close to the rear surface thereof, among the first opening edge 45a, the second opening edge 45b, and the third opening edge 45c of the passage forming member 41. Furthermore, the weft yarn 51 is prevented from coming in contact with a part of each of the dents 15 close to the rear surface thereof, such as the first edge 15b of each of the dents 15. As a result, the weft yarn 51 is smoothly introduced into the yarn inlet 44a of the weft yarn travel passage 44. After that, the weft yarn tensioning device 40 applies the tension to the weft yarn 51.
In the above-mentioned embodiment, the following effects can be obtained.

(1) The shielding member 46 shields all the dent gaps S in the shielded area R, from the rear surface side of the dents 15. This suitably suppresses the leakage of the air toward the rear surface side of the dents 15 through the dent gaps S near the yarn inlet 44a of the weft yarn travel passage 44. As a result, at a position near the yarn inlet 44a of the weft yarn travel passage 44, the weft yarn 51 is prevented from traveling so as to approach the rear surfaces of the dents 15 due to the leakage of the air toward the rear surface side of the dents 15. This suppresses a contact of the weft yarn 51 with a part of the weft yarn travel passage 44 surrounding the yarn inlet 44a, near the yarn inlet 44a of the weft yarn travel passage 44. As a result, the weft yarn 51 is smoothly introduced into the yarn inlet 44a of the weft yarn travel passage 44, which applies the tension to the weft yarn 51.
(2) The second side surface 33d that is the downstream end of the shielding member 46 is positioned on the downstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X, in the front-rear direction of the dents 15. That is, a part of the shielding member 46 is positioned beyond the yarn inlet 44a of the weft yarn travel passage 44, on the downstream side of the yarn inlet 44a in the weft insertion direction X. This suitably suppresses the leakage of the air toward the rear surface side of the dents 15 near the yarn inlet 44a, as compared with a case where the second side surface 33d is disposed at the same position as the yarn inlet 44a in the weft insertion direction X or a case where the second side surface 33d is disposed on the upstream side of the yarn inlet 44a in the weft insertion direction X. This can more suitably suppress a travel of the weft yarn 51 near the rear surfaces of the dents 15 immediately before the yarn inlet 44a of the weft yarn travel passage 44.
(3) The shielding member 46 covers a part of the dent gaps S extending along the entire weft yarn guide passage 17 in the up-down direction of the weft yarn guide passage 17 and a part of the dent gaps S extending downward lower than the lower end of the weft yarn guide passage 17. Specifically, the shielding member 46 covers a part of the dent gaps S along opposite sides of the weft yarn guide passage 17 in the up-down direction thereof, including the weft yarn guide passage 17, from the rear surface side of the dents 15.
Inventors of the present invention have found that the air is easily leaked toward the rear surface side of the dents 15 in an area in the up-down direction of the weft yarn guide passage 17, the area including a part of the dent gaps S extending along the weft yarn guide passage 17 in the up-down direction thereof and a part of the dent gaps S extending downward lower than the lower end of the weft yarn guide passage 17. Then, the shielding member 46 shields an area in which the air is easily leaked toward the rear surface side of the dents 15, that is, the shielding member 46 covers the part of the dent gaps S extending along the weft yarn guide passage 17 in the up-down direction thereof and the part of the dent gaps S extending downward lower than the lower end of the weft yarn guide passage 17. Thus, the shielding member 46 suitably suppresses the travel of the weft yarn 51 near the rear surfaces of the dents 15.
(4) The shielding member 46 also functions as the second vibration suppressing member 302 suppressing the vibration of the dents 15. Thus, the vibration suppressing member 30 may be used as the shielding member 46, which has been already present. For example, since a shielding member 46 is not required to be newly manufactured, the weft yarn 51 is prevented from traveling near the rear surfaces of the dents 15, without an increase in a manufacturing cost of the weft yarn tensioning device 40.
(5) The airjet loom 10 also includes the first vibration suppressing member 301. Thus, the first vibration suppressing member 301 and the second vibration suppressing member 302 serving as the shielding member 46 are arranged on the upstream side of the weft yarn travel passage 44 in the weft insertion direction X. Then, the first vibration suppressing member 301 and the second vibration suppressing member 302 suppress the leakage of the air toward the rear surface side of the dents 15. As a result, the first vibration suppressing member 301 and the shielding member 46 suitably suppresses the travel of the weft yarn 51 near the rear surfaces of the dents 15, at the position near the yarn inlet 44a of the weft yarn travel passage 44.
(6) The front surface of the anti-vibration member 33 of the shielding member 46 is in contact with the rear surfaces of the dents 15. Thus, the anti-vibration member 33 suppresses the leakage of the air through the gaps between the front surface of the anti-vibration member 33 and the rear surfaces of the dents 15. As a result, the weft yarn 51 easily travels away from the rear surfaces of the dents 15 due to a reflected flow of the air by the anti-vibration member 33. As compared with a case where the anti-vibration member 33 is not in contact with the rear surfaces of the dents 15, the weft yarn 51 is suitably prevented from traveling near the rear surfaces of the dents 15.
(7) Since the shielding member 46 shields the dent gaps S, the selvage yarns 54 are not inserted in the dent gaps S, respectively, at a position of the shielding member 46. As a size of the shielding member 46 increases toward the upstream side in the weft insertion direction X, unusable parts of the woven fabric 50 increases, which is not preferable. The first side surface 33c that is an upstream end of the shielding member 46 is positioned on the downstream side of the end selvage yarn 54a of the selvages 53 in the weft insertion direction X. That is, the shielding member 46 does not interfere with a position of the selvages 53. Thus, the position of the shielding member 46 is adjusted, which suitably suppresses the travel of the weft yarn 51 near the rear surfaces of the dents 15 while reducing a cost required for producing the woven fabric 50.
(8) The shielding member 46 covers the plurality of the dent gaps S from the downstream side of the weft yarn detection device 20 in the weft insertion direction X, specifically from the downstream side of the end selvage yarn 54a of the selvage yarns 54 in the weft insertion direction X. That is, the shielding member 46 does not cover only the dent gap S immediately before the yarn inlet 44a of the weft yarn travel passage 44. This suppresses a travel of the weft yarn 51 approaching the rear surfaces of the dents 15 in an area in which the weft yarn 51 passes substantially beyond the selvage yarns 54 and is then introduced into the yarn inlet 44a.

The above-described embodiment may be modified as follows. The embodiment may be combined with the following modified embodiments and implemented within technically consistent range.
In the shielding member 46, the second surface 33b of the anti-vibration member 33 may be spaced away from the rear surfaces of the dents 15.
The shielding member 46 may have a configuration different from that of the vibration suppressing member 30. As illustrated in FIG. 8, the shielding member 46 includes a supporting member 47 and a shielding plate 48 supported by the supporting member 47. The supporting member 47 is fixed to the sley 14. The shielding plate 48 is fixed to an upper end of the supporting member 47. The shielding plate 48 covers the dent gaps S in the shielded area R, from the rear surface side of the dents 15. The shielding plate 48 may be made of an elastic member such as a rubber, or may be a metal plate without elasticity.
The shielding member 46 may cover, from the rear surface side of the dents 15, only a part of the dent gaps S along the weft yarn guide passage 17, or a part of the dent gaps S extending downward lower than the lower end of the weft yarn guide passage 17, in addition to the part of the dent gaps S along the weft yarn guide passage 17.
The shielding member 46 may cover the dent gaps S extending in the up-down direction of the dent gaps S, from the rear surface side of the dents 15.
The second side surface 33d that is the downstream end of the shielding member 46 may be disposed at the same position as the yarn inlet 44a of the weft yarn travel passage 44 in the front-rear direction of the dents 15. In this case, the second side surface 33d of the shielding member 46 is positioned on the same plane as an open surface of the yarn inlet 44a without extending beyond the yarn inlet 44a of the weft yarn travel passage 44.
The number of the dent gaps S covered by the shielding member 46 may be appropriately changed. For example, the shielding member 46 may cover only a dent gap S closest to the upstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X.
As illustrated in FIG. 9, the air jet loom 10 may be configured such that only the weft yarn tensioning device 40 holds a leading end of the weft yarn 51 without using the selvages 53. In this case, the selvage yarns 54 are not inserted in the dent gaps S of the above-described embodiment, respectively, although the selvage yarns 54 are inserted in the dent gaps S of the above-described embodiment. Thus, in the front view of the air jet loom 10, the shielding member 46 covers the dent gaps S existing from the downstream side of the weft yarn detection device 20 and from the upstream side of the yarn inlet 44a of the weft yarn travel passage 44 in the weft insertion direction X, to the yarn inlet 44a. The shielding member 46 covers at least a part of the dent gaps S in which the warp yarns 52 are not inserted, respectively.
In this case, the shielding member 46 may cover all the dent gaps S existing from the downstream end of the weft yarn detection device 20 to the yarn inlet 44a, or may cover only a part of the dent gaps S. In the above-described modified embodiment, the first side surface 33c of the anti-vibration member 33 approaches the weft yarn detection device 20, as compared with the above-described embodiment. As a result, a dimension of the shielding member 46 in the weft insertion direction X increases as compared with the above-described embodiment.
A weft yarn tensioning device (40) for an air jet loom (10) includes: a passage forming member (41); an air discharge portion (42); and a shielding member (46) covering a dent gap (S) formed between dents (15) adjacent to each other in a weft insertion direction (X), from a rear surface side of dents (15). In a front view of the air jet loom (10), the shielding member (46) covers at least a part of the dent gap (S) in which a warp yarn (52) is not inserted among dent gaps (S) existing from a downstream side of a weft yarn detection device (20) in the weft insertion direction (X) and from an upstream side of a yarn inlet (44a) of a weft yarn travel passage (44) in the weft insertion direction (X) to the yarn inlet (44a), from the rear surface side of the dents (15).

Claims

A weft yarn tensioning device (40) for an air jet loom (10) in which a weft yarn (51) is inserted along a weft yarn guide passage (17) formed in a reed (13) and a plurality of dents (15) are arranged in a weft insertion direction (X) of the weft yarn (51), the air jet loom (10) including a weft yarn detection device (20) configured to detect the weft yarn (51) traveling through the weft yarn guide passage (17),
the weft yarn tensioning device (40) being disposed at a position close to a leading end of the weft yarn (51) inserted into the weft yarn guide passage (17) and on a downstream side of the weft yarn detection device (20) in the weft insertion direction (X), and configured to catch the leading end of the weft yarn (51) and apply a tension to the weft yarn (51),

the weft yarn tensioning device (40) comprising:
a passage forming member (41) defining a weft yarn travel passage (44) extending along the weft yarn guide passage (17) in the weft yarn guide passage (17); and

an air discharge portion (42) from which air is discharged to the weft yarn travel passage (44) so that the leading end of the weft yarn (51) is caught inside the passage forming member (41); characterized in that

the weft yarn tensioning device (40) includes a shielding member (46) covering a dent gap (S) formed between the dents (15) adjacent to each other in the weft insertion direction (X), from a rear surface side of the dents (15),and

in a front view of the air jet loom (10), the shielding member (46) covers, from the rear surface side of the dents (15), at least a part of the dent gap (S) existing from a downstream side of the weft yarn detection device (20) in the weft insertion direction (X) and from an upstream side of a yarn inlet (44a) of the weft yarn travel passage (44) in the weft insertion direction (X) to the yarn inlet (44a), at least the part of the dent gap (S) in which a warp yarn (52) is not inserted.
The weft yarn tensioning device (40) for the air jet loom (10) according to claim 1, characterized in that
the shielding member (46) includes an upstream end and a downstream end in the weft insertion direction (X), and

the downstream end of the shielding member (46) is positioned on a downstream side of the yarn inlet (44a) of the weft yarn travel passage (44) in the weft insertion direction (X).
The weft yarn tensioning device (40) for the air jet loom (10) according to claim 1, characterized in that
the shielding member (46) covers a part of the dent gap (S) extending along the entire weft yarn guide passage (17) in an up-down direction of the weft yarn guide passage (17) and a part of the dent gap (S) extending downward lower than a lower end of the weft yarn guide passage (17), from the rear surface side of the dents (15).
The weft yarn tensioning device (40) for the air jet loom (10) according to claim 1, characterized in that
a front surface of the shielding member (46) is in contact with rear surfaces of the dents (15).
The weft yarn tensioning device (40) for the air jet loom (10) according to claim 1, characterized in that
the air jet loom (10) includes a vibration suppressing member (30) including an anti-vibration member (33) made of an elastic member being in contact with the rear surfaces of the dents (15), and a mounting portion (31) for mounting the anti-vibration member (33) to the reed (13), and

the shielding member (46) functions as the vibration suppressing member (30).