JPH10325052A - Weft-detection apparatus for air jet loom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the detection of a weft by uniformizing the received light quantity on a light-receiving face. SOLUTION: This detection apparatus is composed of a supporting means to oppositely position a light projector and a light receptor at both sides of a weft-flying path formed by a deforming reed and a pair of transparent covers 30a, 30b oppositely positioned in front of each of the projector and the receptor interposing the weft-flying path between the covers. The transmission region of the light projected from the projector 32 to the light-receiving face of the receptor 34 is completely enclosed by the covers 30a, 30b and, accordingly, the light is directly transmitted to the light-receiving face without causing the diffusion, and the quantity of received light is uniformized to stabilize the detection of weft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weft detecting device in an air jet loom, and more particularly to an optical weft detecting device suitable for detecting a weft inserted.

[0002]

2. Description of the Related Art As one of optical type weft detecting devices, there is a transmission type weft detecting device described in Japanese Patent Application Laid-Open No. 7-42047. This conventional weft detection device is a U-shaped notch through which a weft passes, and a plate-shaped transparent body in which the corner of the notch is formed in an arc shape, and faces the transparent body via the notch of the transparent body. A light emitter and a light receiver are embedded in a portion to be formed, and a light beam from the light emitter passes through the notch through the transparent body and is received by the light receiver.

[0003]

According to the prior art, a part of the light beam from the projector is diffused when passing through the arc-shaped portion of the U-shaped notch formed by the transparent body. Only a part of the light beam passing through the arc-shaped portion reaches the light receiving surface of the light receiver.

Therefore, the amount of light that has passed through the arc-shaped portion and reached the light-receiving surface is smaller than the amount of light that has reached the light-receiving surface without passing through the arc-shaped portion from the light emitter. As a whole, the amount of received light becomes non-uniform. Therefore, the yarn detection signal when the weft passing through the weft flight path blocks the light of the latter is smaller than the yarn detection signal obtained when the light of the former is blocked, and it becomes difficult to detect the weft. There was a problem.

In other words, there is a problem that the detection of the weft becomes unstable due to the difference in the passing position of the weft on the weft flight path for each weft insertion.

SUMMARY OF THE INVENTION It is an object of the present invention to always perform stable weft detection regardless of the passing position of a weft in a weft flight path.

[0007]

The weft detecting device according to the present invention comprises: a support means for arranging a light emitting and receiving device opposite to each other across a weft flight path defined and formed by a deformed reed; A pair of transparent covers disposed opposite to each other with the weft running path interposed therebetween, and the pair of cover portions is formed of a flat plate including an entire light-passing area of a light beam irradiated from the light emitter to the light receiving surface of the light receiver. It is composed.

According to the structure of the present invention, the light beam from the projector first passes through the cover in front of the projector and then passes through the cover in front of the receiver to reach the receiver. Includes the entire passage area of the light beam irradiated to the light receiving surface of the container, and the light beam irradiated to the light receiving surface is diffused because there is no portion such as an arc-shaped portion in the light transmission region that causes diffusion. All reach the light receiving surface without any change. Therefore, the amount of light received on the light receiving surface can be made uniform.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

The transmission type weft detecting device 20 includes a first support 24 mounted on a lead holder 22 of an air jet loom, and a plate-shaped and opaque fit to one end of the first support. A second support 26, a transparent cover 30 that covers the second support 26 so as to form a cutout 28 in which the wefts fly, and a projector 32 arranged on one side with respect to the cutout 28. And a light receiver 34 arranged on the other side with respect to the cutout 28.

A reed (not shown) composed of a modified reed wing 80 having a weft guide groove for defining and defining a weft flight path is attached to the lead holder 22. The notch 28 of the weft detecting device 20 has a U-shape as shown in FIG. 6 and has substantially the same size as the weft guide groove of the deformed reed 80. The weft detecting device 20 is configured such that the notch 28
It is attached so as to have a positional relationship as shown in FIG.

One end of the first support 24 is formed as a plate-shaped portion 38, has a width (for example, 10 mm) sufficiently larger than the interval between the reeds, and has a recess 40 facing the front side of the weaving. On the other hand, the other end of the first support 24 is a mounting part 42 mounted on the lead holder 22, and the convex part 44 is fitted into the concave part of the lead holder 22, and the inclined convex part 46 is formed. Is brought into contact with the side surface of the lead holder 22, and the inclined surface 48 is brought into contact with the inclined surface of the lead holder 22, and is assembled to the lead holder 22. One end of the first support 24 has a recess 40
Has a projection 50 protruding inwardly at the top, and a hole 52 at the other end through which a mounting bolt passes.

The second support 26 has rear and upper and lower surfaces substantially the same as the inner bottom and upper and lower surfaces of the recess 40. Second
As shown in FIG. 5, the support 26 has a recess 54 with a front portion cut out, and a recess 56 fitted with the projection 50 of the first support 24. Then, the first support 24 is opened so that the recess 54 opens to the weave front side.
Is mounted in the recess 40.

Further, the second support 26 has a pair of vertically extending holes 58 and 60 for receiving the light projector 32 and the light receiver 34 and a pair of holes 58 and 60 respectively.
A pair of slits 62 and 64 that communicate with the pair 4 have a portion facing each other via the recess 54. In addition, the second support 26 has a projection 66 projecting into the recess 54 at the center of the deep bottom of the recess 54 as shown in FIGS. 3 to 5.

The slits 62 and 64 extend in a direction perpendicular to the direction of flight of the weft, and are arranged to face each other. The slits 62 and 64 are formed from rectangular openings as shown in FIGS.

The light emitter 32 and the light receiver 34 are arranged in holes 58 and 60, respectively, and are connected to a connector part 70 provided at the lower end of the first support 24 by electric wires 72 and 74. The light emitter 32 has a light receiving surface 3
It has an optical axis 85 perpendicular to the light-receiving surface 4a, and as shown in FIG. 9, is set so as to irradiate a substantially parallel light ray 83 to the light-receiving surface 34a through the slits 62 and 64. The substantially parallel light beam 83 can be obtained by using a concave lens between the slit 62 and the light emitting source, or by setting the distance between the slit 62 and the projector 32 large.

The cover 30 includes a first cover portion 30a that forms the surface of the notch 28 on the light emitting device 32 side, a second cover portion 30b that forms a surface of the notch portion 28 on the light receiver 34 side,
Third cover portion 30c forming the inner bottom surface of cutout portion 28
A fourth cover 30d covering the rear surface of the second support 26 in the weft flight direction, and a fifth cover portion 30e covering the front surface of the weft in the flight direction.
A sixth cover 30f covering the upper front surface of the second support 26, a seventh cover 30g covering the lower front of the second support 26, and a lower front end of the seventh cover 30g. And a through hole 68 formed at the center of the third cover 30c.

The first cover part 30a and the second cover part 30b are formed of plates having the same thickness. The presence of these covers can prevent fly waste and the like from entering the slits 62 and 64. First
The cover portion 30a is configured to include the entire light passing area of the light beam irradiated on the light receiving surface 34a. That is, in the present embodiment, the light beam from the projector is
Therefore, the first cover portion 30a is configured to include a region substantially equal to the opening of the slit 62. The second cover 30b is also a light receiving surface 3.
It is configured to include the entire area where the light beam irradiated to 4a passes, that is, to include an area substantially equal to the opening of the slit 64. The first cover 30a and the second cover 30a
The cover portion 30b forms a right angle with the third cover portion 30c.

It should be noted that the light beam from the projector 32 is
In the case where the light is irradiated to the light receiving surface 34a without passing through the second and the second cover 64b, the first cover 30a and the second cover 30b
Is configured to include at least a region substantially equal to the light receiving surface 34a.

The cover 30 is adhered to the second support 26. In the assembly of the second support 26 and the cover 30, the engaging step 30h of the cover 30 is engaged with the engaging portion of the first support 24, and the through hole 68 of the cover 30 is provided in the second support. 2
6 are fitted in the recesses of the first support 24 and fitted to the first support 24 in a state of fitting with the protrusions 66 of the sixth support. The protrusion 66 prevents the light beam from reaching the light receiver 34 through the inside of the third cover portion 30c.

Of the light beams from the projector 32, the slit 6
All the light rays radiated to the light receiving surface 34a through the light receiving surfaces 3a and 2b pass through the planar portions of the first cover portion 30a and the second cover portion 30b.
Reaches 4a. Accordingly, the amount of light received on the light receiving surface 34a is uniform, and the amount of light blocked by the weft is the same even if the passing position of the weft differs for each pick, so that stable detection of the weft can always be performed.

First cover part 30a, second cover part 3
0b and the third cover 30c form an arc-shaped (radius 2 mm) edge 31 as shown in FIGS. 7 is a front view of the cover 30 as viewed from the left side in FIG. 1, and FIG. 8 is a cross-sectional view of the cover 30 as viewed from the direction indicated by reference numeral 3 in FIG. The second cover part 30b protrudes about 1 mm from the upper surface 80b of the weft guide groove, and the third cover part 30c protrudes about 1 mm from the inner bottom part 80c of the weft guide groove.

In FIGS. 7 and 8, the air flow from left to right in the weft guide groove moves along the curved surface of the arc-shaped edge projecting into the weft guide groove due to the Coanda effect. Cover part 30b and third cover part 30c
, A stable air flow is obtained. Such a phenomenon effectively works for stable detection of the weft.

As shown in FIG. 10, the upper surface 80 of the weft guide groove
b and the second cover portion 30b have an intersection angle,
The positional relationship between the notch 28 and the weft guide groove of the modified reed 80 may be set. At this time, the light projector 32 emits light so as to include the weft flight area 81. Note that FIG.
In the embodiment shown in FIG. 2, the first cover 30a and the second cover 30b are parallel to each other, and the notch 2
8 and the slits 62 and 64 for the first cover 30a and the second cover 30b, and the light emitter / receiver 3 except that the positional relationship between the reed 8 and the weft guide groove of the modified reed 80 is different.
The positional relationship with respect to 2 and 34 is the same as in the embodiment described above.

In the above embodiment, the first cover 30a and the second cover 30b are not necessarily formed in parallel, but are formed along each side (not shown) of the weft guide groove. (FIG. 11). At this time, the light beam irradiated into the notch 28 is
The incident angle from the light projector to the first cover part 30a is set so as to be parallel to a.

[0026]

According to the present invention, the light emitted from the projector to the light receiving surface of the light receiver directly reaches the light receiving surface without being diffused, so that the amount of light received on the light receiving surface can be made uniform. Therefore, stable weft detection can be performed regardless of the passing position of the weft.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a weft detecting device according to the present invention.

FIG. 2 is a sectional view taken along line 2-2 in FIG.

FIG. 3 is an enlarged sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is an enlarged sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is a sectional view taken along the line 5-5 in FIG. 3;

FIG. 6 is a diagram showing a positional relationship between the weft detecting device of the present invention and a reed wing.

FIG. 7 is a diagram showing a positional relationship between the weft detecting device of the present invention and a reed dent.

FIG. 8 is a diagram showing a positional relationship between the weft detecting device of the present invention and a reed wing.

FIG. 9 is a diagram showing an irradiation state.

FIG. 10 is a diagram showing another positional relationship between the weft detecting device of the present invention and a reed dent.

FIG. 11 is a view showing another shape of the notch.

[Explanation of symbols]

 Reference Signs List 20 weft detecting device 24 first support 26 second support 28 notch 30a first cover 30b second cover 32 light emitter 34 light receiver 62, 64 slit

Claims (1)

[Claims] 1. A support means for arranging a light emitting and receiving device to face each other with a weft running path defined and formed by a deformed reed, and a pair of transparent means disposed in front of each of the light emitting and receiving means to face each other with a weft running path therebetween. A weft detection device for an air jet loom, wherein the pair of cover portions is formed of a flat plate including the entire area through which light beams emitted from the light emitter to the light receiving surface of the light receiver pass.