JP3471549B2 - Weft detector - Google Patents

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 a 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 weft detecting devices, there is a transmissive weft detecting device disclosed in Japanese Patent Laid-Open No. 7-42047. As shown in FIG. 9, this conventional weft detection device is a plate-shaped transparent body 12 having a U-shaped cutout portion 10 through which the weft thread passes, and a portion opposed to the transparent body 12 through the cutout portion 10. The light beam from the light projector 14 passes through the inside of the notch 10 through the transparent body 12 and is received by the light receiver 16.

As shown in FIG. 9, the notch 10 prevents the presence of the weft detecting device from affecting the flight of the weft and prevents the wind surface from accumulating in the notch 10, for example. It has the same shape as the weft guide groove of the reed. Further, the lower surface 10a of the cutout portion 10 is an inclined surface that becomes higher toward the bottom bottom surface 10b side of the cutout portion 10, and the back bottom surface 10b is the floodlight 1.
4 is parallel to the optical axis of the light ray 18a. Although the weft varies depending on the properties of the weft, the performance of the weft inserting device, etc., the weft usually flies within a weft detection range within approximately 2.5 mm from the inner bottom surface of the notch 10, and in some cases, the notch in FIG. It may also pass through the upper left part of 10.

However, in the conventional weft detecting device, the lower surface 10a of the notch 10 is the inner bottom surface 1 even though the inner bottom surface 10b is parallel to the optical axis of the light beam 18a from the projector 14.
Since it is inclined by an angle θ with respect to the line orthogonal to 0b,
When the light ray 18a is emitted from the transparent body 12 to the cutout portion 10, it is refracted at an angle θ ′, and as a result, a portion where irradiation is insufficient is formed at the upper left corner portion in FIG. Therefore, it is not possible to detect the weft yarn flying in the corner portion.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to stabilize the detection of weft yarns by uniformly irradiating a predetermined detection range within the cutout with light rays.

[0006]

SOLUTION, ACTION, EFFECT The present invention relates to a weft detecting device in which a supporting means mounted on a loom and a part of the supporting means for forming at least a part of a U-shaped notch in which the weft fly. And a light-projecting means arranged on one side with respect to the cutout portion, and a light-receiving means arranged on the other side with respect to the cutout portion. The cover has a transparent cover portion forming a surface of the cutout portion on the side of the light projecting unit. The inclination angle of the light incident surface (the surface on the light projecting means side) of the cover portion with respect to a line perpendicular to the inner bottom surface of the cutout portion and the incident angle of the light beam from the light projecting means to the cover portion are the cover. The optical axis of the light beam emitted from the portion to the cutout portion is set to a value parallel to the inner bottom surface of the cutout portion.

When the optical axes of the light rays passing through the cutout portions are parallel, the light rays are evenly applied to the weft detection range within the cutout portions. Therefore, according to the present invention, there is no possibility that an insufficiently irradiating portion is formed in the weft detection range within the cutout portion, and the weft detection is stabilized.

The inclination angle and the incident angle are equal to the inclination angle of the light emitting surface of the cover portion (the surface opposite to the light projecting means) with respect to the line perpendicular to the bottom surface of the notch. You can With this configuration, the thickness dimension of the cover portion can be set to a constant value, and the light projecting means can be arranged to project the light beam parallel to the inner bottom surface of the cutout portion.

Instead of this, the inclination angle is θ ₂ , the incident angle is i ₁ , the inclination angle of the light emitting surface of the cover portion with respect to a line perpendicular to the inner bottom surface of the cutout portion is θ ₁ , and the cover portion is When the refraction angle of the light beam emitted from the to the cutout portion is γ ₂ and the refractive index of the cover portion with respect to air is n, the inclination angle θ ₂ and the incident angle i ₁ are either _one of the following. You may set to the value which satisfies a formula.

Sin i ₁ = nsin {sin ^-1 (si
nγ ₂ / n) -θ ₁ + θ ₂ }

Sin ₁ = nsin {θ ₁ + θ ₂ -s
in ^-1 (sin γ ₂ / n)}

[0012] In a preferred embodiment, the supporting means is a pair of holes in which the light projecting means and the light receiving means are arranged, and a pair of slits extending in a direction intersecting the weft flying direction. And a pair of slits communicating with the cutout portion at a portion facing each other through the cutout portion. Each slit may be provided with a semi-cylindrical lens that is long in the longitudinal direction of the slit.

The support means includes a first support having a plate-shaped portion at one end and a plate-shaped and opaque second support disposed in the plate-shaped portion. The means and the light receiving means are arranged on the second support.
The first support has a recess in which the second support is fitted in the plate-shaped portion.

The cover further includes a second cover portion forming a surface of the cutout portion on the light receiving means side, a third cover portion forming an inner bottom surface of the cutout portion, and a weft flying. It is possible to have a fourth cover portion that covers a front surface in the direction and a fifth cover portion that covers a rear surface in the weft flying direction. Further, the cover further has a through hole penetrating the third cover portion in a thickness direction thereof, and the supporting means has a protrusion fitted in the through hole on the inner bottom surface. be able to.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 5, a light transmission type weft detecting device 20 includes a first support 24 mounted on a lead holder 22 of a loom, and the first support. A plate-like and opaque second support 26 fitted to one end of the
A transparent cover 30 covering the second support 26 so as to form a notch 28 in which the wefts fly, a projector 32 arranged on one side with respect to the notch 28, and a other side with respect to the notch 28. And a light receiver 34 arranged. A reed holder 22 of the loom is provided with a reed (not shown) having a weft guide groove. Then, the weft detection device 20
The notch 28 is provided so as to coincide with the weft guide groove of the reed.

One end of the first support 24 has a plate-shaped portion 38.
And has a recess 40 facing the weave side.
On the other hand, the other end portion of the first support 24 is the mounting portion 42 mounted on the lead holder 22, and the convex portion 44.
Is fitted in the recess of the lead holder 22, the inclined convex portion 46 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. To be One end of the first support member 24 has a protrusion 50 projecting inside the upper portion of the recess 40, and the other end thereof has a hole 52 through which a mounting bolt is inserted.

The second support 26 has a rear surface and an upper and lower surface that are substantially the same as the inner bottom surface and the upper and lower surfaces of the recess 40. Second
The support 26 has a recess 54 formed by cutting out a front portion of the support 26, and a recess 56 fitted with the protrusion 50 of the first support 24. Is arranged in the recess 40 of the first support 24.

The second support 26 also has a pair of vertically extending holes 58 and 60 for accommodating the light projector 32 and the light receiver 34, respectively, and a pair of holes 58 and 60 respectively communicating with the recess 54. Slits 62 and 64
Has a portion facing each other through the recess 54, and has a projection 66 projecting into the recess 54 at the center of the bottom of the recess 54. The slits 62, 64 extend in a direction intersecting the weft flying direction (depth direction of the cutout portion 28).

The cover 30 has a first cover portion 30a forming a surface of the cutout portion 28 on the side of the projector 32, and a second cover portion 30b forming a surface of the cutout portion 28 on the side of the light receiver 34.
Third cover portion 30c forming the inner bottom surface of the cutout portion 28
A fourth cover portion 30d that covers the front surface of the weft in the flight direction, a fifth cover portion 30e that covers the rear surface of the weft in the flight direction, and an upper portion of the second support 26. A sixth cover portion 30f for covering the front surface and a second support 26
Cover portion 30g for covering the lower front surface of the lower cover and an engagement step portion 30h formed at the lower end portion of the front surface of the seventh cover portion 30g.
And a through hole 6 formed in the center of the third cover portion 30c
8 and. The angle formed by the second cover portion 30b and the third cover portion 30c is a right angle.

The cover 30 is adhered to the second support 26. In the assembly of the second support body 26 and the cover 30, the engagement step portion 30h of the cover 30 engages with the engagement portion of the first support body 24, and the through hole 68 of the cover has the second support body. Two
In the state of being fitted with the projection 66 of No. 6, it is fitted into the recess 40 of the first support 24, and is also bonded to the first support 24. The projection 66 allows the irradiation light to emit light to the third cover portion 30.
It is prevented to reach the side of the light receiver 34 through the inside of c.

The projector 32 and the receiver 34 are arranged in the holes 58 and 60, respectively, and the electric wire 72 is connected to the connector portion 70 provided at the lower end of the first support 24.
And 74. A long semi-cylindrical lens extending in the longitudinal direction of the slit 62 may be arranged between the slit 62 and the projector 32. In detail, this kamaboko lens is arranged such that the chord direction of the arc-shaped lens is orthogonal to the longitudinal direction of the slit and the convex surface of the lens is on the slit side. In addition, the kamaboko type lens is used for the projector 3
2 covers the entire light emitting surface. Therefore, by arranging the kamaboko type lens, the irradiation light from the light projector 32 can be focused on the slit 62.

As shown in FIG. 6, the inner bottom surface 28 of the recess 28 is
a is a flat surface and is the first cover portion 30a of the cover 30.
Are formed in a plate shape having the same thickness dimension. The first cover portion 30a is inclined at a predetermined angle with respect to the inner bottom surface 28a so that the first cover portion 30a is higher toward the inner bottom surface 28a. The projector 32 has holes 5 so that the optical axis of the light beam from the projector 32 toward the first cover portion 30a is parallel to the bottom surface 28a.
It is located at 8.

The first cover portion 30 for the inner bottom surface 28a
The angle θ of the light emitting surface 82 of a (the surface opposite to the projector 32)
₁ and angle of light incident surface 80 (surface on the side of the projector 32) θ ₂
Are the same. The incident angle i ₁ of the light ray from the projector 32 to the light incident surface 80 of the first cover portion 30a and the refraction angle γ ₂ of the light ray at the light emitting surface 82 of the first cover portion 30a are mutually and Equal to angles θ ₁ and θ ₂ . The refraction angle γ ₂ of the light ray from the projector 32 at the light incident surface 80 of the first cover portion 30a and the incident angle i ₂ of the light ray at the light emitting surface 82 of the first cover portion 30a are the same value. .

From the above, the light beam 9 from the projector 32 is
0 indicates the first cover portion 30a by reference numeral 92 as shown in FIG.
The light beam 94 passing through the inside of the cutout portion 28 travels in a state where its optical axis is parallel to the inner bottom surface 28a although it is displaced by passing as shown in FIG. As a result, the weft detection range within a predetermined distance from the inner bottom surface 28a is uniformly illuminated.

When the weft exists within the weft detection range within the cutout, the amount of light reaching the photodetector 34 becomes smaller than when the weft does not exist within the weft detection range within the cutout. Therefore, the presence or absence of the weft is detected by the amount of light received by the light receiver 34. At this time, in the weft detection device 20, the weft detection range in the cutout portion 28 is uniformly illuminated,
Since there is no possibility that an insufficiently illuminated portion will be formed in the weft detection range within the cutout portion 28, the weft can be reliably detected.

Even if the angles θ ₁ and θ ₂ of the light emitting surface and the light incident surface of the first cover portion 30a are different as shown in FIGS. 7 and 8, the weft detection area in the cutout portion is uniformly illuminated. be able to.

That is, as shown in FIG. 7 and FIG.
The angle of incidence of the light ray 90 from the projector onto the light incident surface 80, the angle of incidence of the light ray 90 onto the light emitting surface 82, the refraction angle at the light incident surface 80, the refraction angle at the light emitting surface 82, parallel to the inner bottom surface of the notch. , A straight line perpendicular to the light incident surface 80, and a straight line perpendicular to the light emitting surface are respectively i ₁ , i ₂ , γ ₁ ,
When γ ₂ , 96, 84 and 86 are set, the optical axis of the light ray 94 passing through the inside of the notch is parallel to the straight line 96,
The tilt angle θ ₂ and the incident angle i ₁ may be set.

Therefore, the inclination angle θ ₂ and the incident angle i ₁ are set to values satisfying the following expression (1) in the case of FIG. 7, and the following expression (2) in the case of FIG. ) Is satisfied.

Sini ₁ = n · sin {sin ⁻¹ (sin γ ₂ / n) −θ ₁ + θ ₂ } ... (1)

Sini ₁ = n · sin {θ ₁ + θ ₂ −sin ⁻¹ (sin γ ₂ / n)} ... (2)

The above details will be described in detail below.

In FIG. 7, one angle θ ₃ formed by the light emitting surface 82 and the line 84 is 90 ° −θ ₁ + θ ₂ , and one angle θ ₄ formed by the light emitting surface 82 and the line 84 is. 90 ° + θ ₁
−θ _2, which is the angle θ ₅ formed by the light emitting surface 82 and the straight line 92.
Is 90 ° -i ₂ . Thereby, the following equations (3) and (4) are obtained.

180 ° = γ ₁ + 90 ° -i ₂ + 90 ° + θ ₁ −θ ₂ (3)

0 = γ ₁ −i ₂ + θ ₁ −θ ₂ (4)

Further, equation (5) can be obtained from the refractive index of the first cover portion 30 with respect to air, equations (5) to (6) can be obtained, and equations (4) to (7) can be obtained. By substituting the equation (7) into the equation (5) to eliminate γ ₁ , the equation (8) can be obtained, and the equation (6) to the equation (9) can be obtained.

N = sini ₁ / sin γ ₁ > 1 ... (5)

[0037] _{sini 1 / sinγ 1 = 1 /} n ··· (6)

I ₂ −γ ₁ = θ ₁ −θ ₂ (7)

N = sini ₁ / sin (i ₂ −θ ₁ + θ ₂ ) ... (8)

I ₂ = sin ⁻¹ (sin γ ₂ / n) (9)

Then, by substituting the equation (9) into the equation (8) and transforming it, the above equation (1) can be obtained.

Similarly, in FIG. 8, the angle θ ₆ formed by the straight lines 84 and 86 is θ ₁ + θ ₂ , and the light emitting surface 82 and the straight line 8
The angle θ ₇ formed with 4 is 90−θ ₁ −θ ₂ . Thereby, the following formula (10) can be obtained, and the formula (11) can be obtained by substituting the formula (10) into the formula (5) and eliminating γ ₁ .

I ₂ + γ ₁ = θ ₁ + θ ₂ (10)

N = sini ₁ / sin (θ ₁ + θ ₂ −i ₂ ) ... (8)

Then, by substituting the equation (9) into the equation (11) and transforming it, the above equation (2) can be obtained.

In any of the above embodiments, θ ₁ is determined by the shape of the notch 28, that is, the shape of the reed wing, so that i ₁ and θ _{2 are set} so that γ ₂ becomes equal to θ _1.
Is set so that the optical axis of the light beam 94 is notched 28
It passes through the inside of the notch 28 while being parallel to the inner bottom surface 28a.

The present invention is not limited to the above embodiment. For example, a light projector that directs the light beam generated by the light emitting element as described above by a light guide may be used. Also, the first
Alternatively, only the second cover portions 30a and 30b may be transparent. Further, the cover 30 includes the first cover portion 30a.
May have only.

[Brief description of drawings]

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

2 is an end view taken along line 2-2 of FIG.

3 is an enlarged sectional view taken along line 3-3 of FIG.

FIG. 4 is an enlarged cross-sectional view taken along line 4-4 of FIG.

5 is a cross-sectional view taken along line 5-5 of FIG.

FIG. 6 is an enlarged view of a portion near a cutout portion for explaining a passing state of a light ray in the weft detection device of FIG.

FIG. 7 is an enlarged view of the vicinity of a first cover portion for explaining a light beam passing state in another embodiment of the weft yarn detecting device of the present invention.

FIG. 8 is an enlarged view of the vicinity of a first cover portion for explaining a light beam passing state in still another embodiment of the weft yarn detecting device of the present invention.

FIG. 9 is an enlarged view of the vicinity of a cutout portion for explaining a light beam passing state in a conventional weft detection device.

[Explanation of symbols]

20 Weft detection device 22 Loom lead holder 24 First support 26 Second support 28 Notch 30 covers 32 Floodlight 34 Receiver 58, 60 holes in the second support 62 Slit of second support 30a cover part

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-42047 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) D03D 51/34 101

Claims (4)

(57) [Claims] 1. A supporting means to be mounted on a loom, a cover for covering a part of the supporting means so as to form at least a part of a U-shaped notch in which wefts fly, and one of the notches. Side, and a light receiving means arranged on the other side with respect to the cutout portion, and the cover is a transparent cover portion forming a surface of the cutout portion on the side of the light projection means. The angle of inclination of the light incident surface of the cover portion with respect to a line perpendicular to the bottom surface of the cutout portion and the incident angle of the light beam from the light projecting means to the cover portion are determined from the cover portion to the cutout portion. The weft detecting device, wherein the optical axis of the light beam emitted to is parallel to the inner bottom surface of the cutout portion. 2. The weft detecting device according to claim 1, wherein the inclination angle and the incident angle are equal to an inclination angle of a light emitting surface of the cover portion with respect to a line perpendicular to a bottom bottom surface of the cutout portion. 3. The tilt angle is θ ₂ , the incident angle is i ₁ ,
The inclination angle of the light emitting surface of the cover portion with respect to a line perpendicular to the inner bottom surface of the cutout portion is θ ₁ , the refraction angle of the light beam emitted from the cover portion to the cutout portion is γ ₂ , and the cover portion with respect to air. when the refractive index of the set to n, the angle of inclination theta ₂
And the incident angle i _{1 is, sini 1 = n · sin {} sin -1 (sinγ 2 / n)
The weft yarn detecting device according to claim 1, wherein the weft yarn detecting device is set to a value of −θ ₁ + θ ₂ }. 4. The inclination angle is θ ₂ , the incident angle is i ₁ ,
The inclination angle of the light emitting surface of the cover portion with respect to a line perpendicular to the inner bottom surface of the cutout portion is θ ₁ , the refraction angle of the light beam emitted from the cover portion to the cutout portion is γ ₂ , and the cover portion with respect to air. when the refractive index of the set to n, the angle of inclination theta ₂
And the incident angle i _{1 is, sini 1 = n · sin {} θ 1 + θ 2 -sin -1 (si
The weft detection device according to claim 1, wherein the weft detection device is set to a value such that nγ ₂ / n)}.