JP5999136B2 - Weft detection device in air jet loom - Google Patents

Description

  The present invention relates to a weft detection device in an air jet loom, and more particularly to a weft detection device in an air jet loom in which wefts are inserted by air injection, and the wefts inserted are beaten by wings on a sleigh.

  In order to find out the flying state of the weft that has a great influence on the quality of the fabric, weft detection device provided with a light-emitting optical fiber and a light-receiving optical fiber in a support member that separates the warp rows and enters and exits the warp opening Is disclosed (for example, see Patent Document 1). In this weft detection device, as shown in FIG. 10, the support member 51 is disposed so as to face the flying path 53 of a weft (not shown) whose tip is formed by a guide recess 52 a of the wing 52. Yes. As shown in FIGS. 11A and 11B, the support member 51 is configured by coupling a pair of split pieces 51a and 51b, and the distal end surfaces of the light projecting optical fiber 54 and the light receiving optical fiber 55 are supported. It is exposed from an exposure port 51 c formed at the tip of the member 51. Each of the optical fibers 54 and 55 is composed of a multi-optical fiber in which a plurality of fiber elements are bundled. The support member 51 is formed with a smooth convex curved surface on the outer surface of the front end portion 56 of the support member 51 and the front end surfaces of the optical fibers 54 and 55 so that the flying weft can be detected without fear of damaging the warp. ing.

JP 2010-209478 A

  Since the light projecting optical fiber 54 and the light receiving optical fiber 55 are arranged in a thin support member 51 that enters the warp string, the thickness of the light projecting optical fiber 54 and the light receiving optical fiber 55 is the size of the support member 51 (thick). )) And cannot be made thicker than necessary.

  When the end surfaces of the light projecting optical fiber 54 and the light receiving optical fiber 55 are convex curved surfaces as in Patent Document 1, as shown in FIGS. 12A and 12B, they correspond to the guide concave portions 52 a of the wings 52. In the lower jaw portion, there are unprojectable ranges A3 on both the upper and lower sides of the projection range A1 (detection area) in the flying path 53 on the back side from the tangent L1 parallel to the back surface of the wing 52. Further, in the light receiving optical fiber 55, there is an unreceivable range A <b> 4 below the light receiving range A <b> 2 (detection area) occupying the flight path 53. Therefore, the overlapping range of the light projection range A1 and the light receiving range A2 is narrowed, and the weft detection performance is lowered.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a weft detection device capable of improving the detection performance of a flying weft.

A weft detection device in an air jet loom that solves the above-mentioned problems is a weft detection device in an air jet loom that inserts a weft by injection of compressed air and beats the inserted weft with a wing on a sleigh. A supporting member disposed to face the flying path of the weft yarn; a light-emitting optical fiber and a light-receiving optical fiber provided in the supporting member and having an end surface opposed to the flying path; The light projecting optical fiber and the light receiving optical fiber have an adjacent edge that is an edge adjacent to the other optical fiber of the end faces, and an anti-adjacent edge that is an edge opposite to the other edge. An angle formed between the adjacent edge of one of the light projecting optical fiber and the light receiving optical fiber and the other non-adjacent edge of the light projecting optical fiber and the light receiving optical fiber. It was set so that at least one of the boundaries between the two detection areas would fit the flight path . Here, the “detection area” means a range occupied by the light irradiated from the optical fiber in the flying path of the weft in the optical fiber for projection, and the light that can be received in the optical path for receiving light is the path of the weft flying Means the range occupied by. In addition, “the optical fiber side boundary of the light detection area of both detection areas” means the upper boundary line of the light projecting range and the light receiving range, and the tangent line parallel to the back surface of the wing in the lower jaw part corresponding to the guide recess of the wing Means the point where Further, “to match” includes not only perfect match but also a slight difference within a range that does not cause a problem in the weft detection performance.

  According to this configuration, of the end faces of the light projecting optical fiber and the light receiving optical fiber, the adjacent edge which is the edge adjacent to the other optical fiber and the opposite edge which is the opposite edge are flat. The angle formed by the adjacent edge of one of the light projecting optical fiber and the light receiving optical fiber and the other non-adjacent edge of the light projecting optical fiber and the light receiving optical fiber is both It was set so that at least one of the boundaries of the detection area would fit. Therefore, compared with the prior art, the overlapping area of the detection areas of the light projecting optical fiber and the light receiving optical fiber is increased, and the detection areas can be made coincident with each other in the upper part of the flight path where the weft presence frequency is relatively high. As a result, the flying weft detection performance can be improved.

  The support member is provided so as to be able to enter / exit into the warp opening from between the warp rows, and the light projecting optical fiber and the light receiving optical fiber are directed to the guide recesses formed in the wings in the state where the end surface is oriented Are preferably provided so as to be arranged vertically. In this configuration, the light receiving optical fiber receives the reflected light projected from the light projecting optical fiber and reflected by the guide recess, so that the detection accuracy is higher than the configuration in which the weft is detected by the reflected light reflected by the weft. Get higher. Further, the thickness of the support member can be reduced compared to the configuration in which the end faces of the light projecting optical fiber and the light receiving optical fiber are arranged side by side, and the resistance when the support member enters and exits the warp opening is reduced.

  The support member is provided at a weft arrival position where the weft reaches outside the warp opening, and the light projecting optical fiber and the light receiving optical fiber are provided such that the end faces are aligned along the weft insertion direction. Is preferred. The weft detection device having this configuration is used to detect whether or not the front end of the weft has reached the outside of the warp opening, that is, the weft insertion end. Therefore, the light receiving optical fiber receives the reflected light projected from the light projecting optical fiber and reflected by the weft, and detects the weft. Further, unlike the conventional weft detection device for detecting the weft insertion end, since the lens is not used for the light projecting portion and the light receiving portion, the width of the device (size in the direction parallel to the weft insertion direction) is reduced. Therefore, the length of the weft necessary for weft insertion can be reduced.

  The light projecting optical fiber and the light receiving optical fiber are preferably formed such that the plane is inclined with respect to a plane perpendicular to the axial direction of each optical fiber. According to this configuration, the angle formed by the end surface with the plane perpendicular to the axial direction of the optical fiber is reduced as compared with the case where only the end surface of one optical fiber is inclined with respect to the plane perpendicular to the axial direction of the optical fiber. be able to.

  According to the present invention, the flying weft detection performance can be improved.

The schematic perspective view of a weft insertion apparatus. The partially broken schematic side view which shows the positional relationship of a wing and a weft sensor. (A) is a model partial side view of a weft sensor, (b) is the elements on larger scale of (a). (A) is a schematic diagram of SI type optical fiber, (b) is a schematic diagram which shows the incident angle and refraction angle in the optical fiber for light reception. (A), (b), (c) is a schematic diagram explaining the effect | action of an optical fiber. (A), (b) is a schematic diagram explaining the effect | action of a weft sensor. The typical fragmentary sectional view of the weft sensor of 2nd Embodiment. (A), (b), (c), (d) is a typical partial side view of a weft sensor according to another embodiment. (A), (b) is a typical fragmentary sectional view of the weft sensor of another embodiment, respectively. The sectional side view which shows the relationship between the weft sensor of a prior art, and a heel. (A) is a partial front view of a conventional weft sensor, (b) is a schematic cross-sectional view taken along line AA of (a). (A), (b) is a schematic diagram explaining the effect | action of the weft sensor of a prior art.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, in the air jet loom, a main nozzle 11 for weft insertion, a sub nozzle 12 for weft insertion, and a flange 13 are fixed on a sley 14. The eaves 13 are formed by arranging a plurality of eaves wings 15 having guide recesses 15a in the weft insertion direction. The guide recesses 15a of the plurality of kite wings 15 form an inner kite passage 16 that constitutes a weft flying path. The sub nozzle 12 is fixed to the sley 14 via a support block 17 so that the position of the sub nozzle 12 can be adjusted. The sub nozzle 12 can enter and exit the opening of the warp T from between the rows of the warp T as the sley 14 swings.

  A plurality of weft sensors 20 (only one is shown) for detecting the weft Y flying in the inner passage 16 are fixed to the sley 14 via a support block 21 so that the position can be adjusted. The weft sensor 20 can enter and exit the opening of the warp T from between the rows of the warp T as the sley 14 swings. In addition, a weft sensor 30 that detects that the tip of the weft Y that has been inserted has reached the end of the weft insertion range is fixed to the sley 14 via a support block 31 so that the position can be adjusted.

Hereinafter, the weft sensor 20 will be described.
As shown in FIG. 2, the weft sensor 20 has a rod-shaped support member 22 fixed to a support block 21, and the distal end portion of the support member 22 is aligned with a row of warps T as the slay 14 swings. It is possible to enter and exit the opening of the warp T from between. The support member 22 is configured by combining a pair of split pieces 22a and 22b as in the weft detection device of Patent Document 1, and as shown in FIGS. 3 (a) and 3 (b), the pair of split pieces 22a and 22b. The accommodation space 23 comprised by these is provided. The support member may be integrally formed with a cylindrical piece. The accommodating space 23 accommodates a light projecting optical fiber 24 and a light receiving optical fiber 25. The light projecting optical fiber 24 and the light receiving optical fiber 25 are provided so that the front end surfaces 24a and 25a are vertically aligned in a state of being directed to the guide recess 15a formed in the wing 15. That is, the end surfaces of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged so as to face the flight path. In this embodiment, the light projecting optical fiber 24 is provided on the upper side, and the light receiving optical fiber 25 is provided on the lower side.

  A light-emitting element and a light-receiving element are provided in a fixed portion (not shown) that is fixedly arranged regardless of the swing of the sley 14. The light projecting optical fiber 24 is connected to the light emitting element via an optical fiber made of plastic fiber. An LED (light emitting diode) is used as the light emitting element. The light receiving optical fiber 25 is connected to the light receiving element through an optical fiber made of plastic fiber. A PD (photodiode) is used as the light receiving element.

  The light received by the front end surface 25a of the light receiving optical fiber 25 reaches a PD (not shown) via the light receiving optical fiber 25, and the PD outputs an electric signal corresponding to the amount of received light to a control unit (not shown). . The control unit determines the presence or absence of the weft Y based on the input of the electrical signal. The weft sensor 20, the plastic fiber, the light emitting element, the light receiving element, and the control unit constitute a weft detecting device.

  As shown in FIG. 3B, the light projecting optical fiber 24 and the light receiving optical fiber 25 are multi-optical fibers in which a plurality of fiber elements 26 are bundled. For convenience, in FIG. 2 and FIG. The optical fiber 24 for light reception and the optical fiber 25 for light reception are illustrated as one optical fiber. Hereinafter, as appropriate, the light projecting optical fiber 24 and the light receiving optical fiber 25 are illustrated as one optical fiber. In this embodiment, the fiber element 26 is an SI type multi-mode fiber made of glass fiber. As shown in FIG. 4A, the SI type multimode fiber has a structure in which the refractive index of the core portion 41 that transmits the light irradiated from the light source 40 is uniform.

  Further, as shown in FIG. 3B, the light projecting optical fiber 24 and the light receiving optical fiber 25 are adjacent edge portions 24b which are edge portions on the side adjacent to the other optical fiber of the end surfaces (tip surfaces 24a, 25a). , 25b and anti-adjacent edges 24c, 25c, which are edges on the opposite side, are formed in a plane. The angle formed by one adjacent edge of the light projecting optical fiber 24 and the light receiving optical fiber 25 and the other non-adjacent edge of the light projecting optical fiber 24 and the light receiving optical fiber 25 is the boundary between the two detection areas. Was set so that at least one of them would fit. More specifically, in this embodiment, both of the light projecting optical fiber 24 and the light receiving optical fiber 25 are end surfaces (tip surfaces 24a) such that the adjacent edge portions 24b and 25b and the non-adjacent edge portions 24c and 25c are respectively in one plane. 25a). Then, the angle formed by the front end surface 25a of the light receiving optical fiber 25 and the front end surface 24a of the light projecting optical fiber 24 was set so that the boundary between the light projecting optical fibers in the detection areas of both of them matched. In this embodiment, the light projecting optical fiber 24 and the light receiving optical fiber 25 are formed such that the tip surfaces 24a and 25a are inclined with respect to a plane H perpendicular to the axial direction of each optical fiber.

  The front end surface 24a of the light projecting optical fiber 24 and the front end surface 25a of the light receiving optical fiber 25 are exposed from the exposure port 23a of the housing space 23, and the light that has passed through the light projecting optical fiber 24 passes through the front end surface 24a. Reflected light, which is projected toward the inner passage 16 (flight passage) and is reflected by the guide recess 15a, is incident on the distal end surface 25a of the light receiving optical fiber 25.

  In order to transmit light at the core-cladding boundary with total reflection in the light receiving optical fiber 25, the refraction angle r1 in the light receiving optical fiber 25 must be 20 ° or less, as shown in FIG.

  The critical angle from the glass to the air is about 41 to 43 °, and total reflection occurs when the incident angle is greater than this angle. The angle formed by the tip surface 25a with respect to the incident light for receiving the light incident on the light receiving optical fiber 25 without totally reflecting it varies depending on the type of optical fiber, the refractive index of the glass, and the wavelength of the light used. In the case of the optical fiber used in the test, the incident angle i1 must be about 30 ° or less in order to keep the refraction angle r1 at 20 ° or less in order to transmit the core-cladding boundary by total reflection in the light receiving optical fiber 25. This determines the light receiving range of about 60 ° (30 ° on one side).

  As shown in FIG. 5A, when both the front end surfaces 24a, 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are planes orthogonal to the axial direction of the optical fiber, the light projecting optical fiber 24 and the light receiving optical fiber 25 Due to the difference in the position in the vertical direction, the light projecting range of the light projecting optical fiber 24 and the light receiving range of the light receiving optical fiber 25 do not coincide with each other. When the front end surface of the light receiving optical fiber 25 is a plane inclined with respect to the axial direction of the optical fiber as shown in FIG. 5B, the light receiving range of the light receiving optical fiber 25 can be shifted. Further, as shown in FIG. 5C, when the front end surface 24a of the light projecting optical fiber 24 is a plane inclined with respect to the axial direction of the optical fiber, the light projecting range of the light projecting optical fiber 24 can be shifted. .

  For example, in FIG. 5B, one boundary of the light receiving range when the front end surface 25a of the light receiving optical fiber 25 is perpendicular to the axial direction of the optical fiber is a boundary line Lha indicated by a two-dot chain line, and the front end surface 25a is the optical fiber. An angle formed by a plane perpendicular to the axial direction is defined as θ. When the angle formed by the boundary line Lhb and the boundary line Lha when the distal end surface 25a is inclined is α, the light projecting / receiving range can be matched by matching the angle α and the angle θ.

  In the weft detection device disclosed in Patent Document 1, a light projecting optical fiber 54 and a light receiving optical fiber 55 are used, and a light projecting optical fiber is used to suppress warp damage when the support member 51 enters and exits the warp opening. 54 and the optical fiber 55 for light reception are formed in the convex curved surface. In the weft detection device disclosed in Patent Document 1, no consideration has been given to increasing the overlap of the light projecting and receiving ranges of the light projecting optical fiber 54 and the light receiving optical fiber 55. Since the end surfaces of the light projecting optical fiber 54 and the light receiving optical fiber 55 are convex curved surfaces, the overlapping range between the light projecting range A1 and the light receiving range A2 is narrowed, and the weft detection performance is degraded.

  In this embodiment, in order to increase the degree of overlap between the light projecting range of the light projecting optical fiber 24 and the light receiving range of the light receiving optical fiber 25, the front end surface 24 a of the light projecting optical fiber 24 and the front end of the light receiving optical fiber 25. Both surfaces 25a are composed of adjacent edges 24b and 25b and anti-adjacent edges 24c and 25c. The angle formed by the adjacent edge portion 25b of the light receiving optical fiber 25 and the non-adjacent edge portion 24c of the light projecting optical fiber 24, that is, the light projecting optical fiber side of the detection area of the light projecting optical fiber 24 and the light receiving optical fiber 25 is shown. The boundary was set to match. In FIG. 6A and FIG. 6B, the boundary between the two detection areas on the side of the optical fiber for light projection is the upper line Lu indicating the light projection range and the eyelid in the lower jaw corresponding to the guide recess 15a of the wing 15 It means a location C where the back surface of the wing 15 and a parallel tangent L1 intersect.

  Since both the light projecting optical fiber 24 and the light receiving optical fiber 25 are formed so that the adjacent edge portions 24b and 25b and the non-adjacent edge portions 24c and 25c are in one plane, the angle of the front end surface 24a is The angle of the front edge surface 25a is the same as the angle of the adjacent edge 25b and the anti-adjacent edge 25c, the same as the angle of the adjacent edge 24b and the anti-adjacent edge 24c. For this reason, in the light projecting optical fiber 24 and the light receiving optical fiber 25, the angle θ formed by the distal end surface 24a and the distal end surface 25a is set so that the boundary between the light projecting optical fibers in the detection areas of both faces.

  With respect to the weft detection device (conventional technology) having the configuration disclosed in Patent Document 1 and the weft detection device having the configuration of the embodiment, the overlapping degree of the light projecting and receiving ranges was obtained by simulation. As shown in FIGS. 6 (a) and 6 (b), the overlapping state of the light emitting / receiving range is such that the guide on the back side from the tangent L1 parallel to the back surface of the wing 15 in the lower jaw portion corresponding to the guide recess 15a of the wing 15 It calculated | required from the overlap of the light projection range A1 and the light reception range A2 which occupy for the recessed part 15a. As the light projecting optical fiber 24 and the light receiving optical fiber 25 according to this embodiment, a simulation is performed with a configuration in which the end faces 24a and 25a are inclined at an angle θ (= 10 °) with respect to a plane perpendicular to the axial direction of each optical fiber. went. Further, the angle β formed between the axial direction of the optical fibers of the light projecting optical fiber 24 and the light receiving optical fiber 25 and the vertical direction (direction in which the tangent L1 extends) is set to 55 °.

  The light projecting range A1 of the light projecting optical fiber 24 in the embodiment is a range with dots shown in FIG. 6A, and the light receiving range A2 of the light receiving optical fiber 25 is a range with dots shown in FIG. 6B. Became. The light projection range A1 of the conventional light projecting optical fiber 54 is a range with dots shown in FIG. 12A, and the light receiving range A2 of the light receiving optical fiber 55 is a range with dots shown in FIG. 12B. Became.

According to this embodiment, the following effects can be obtained.
(1) The weft sensor 20 is a weft detection device in an air jet loom that inserts the weft Y by injection of compressed air and beats the inserted weft Y by the wings 15 on the sley 14. And the supporting member 22 arranged facing the flying path of the weft yarn (inner ridge path 16), provided in the supporting member 22, and the end faces (tip surfaces 24a, 25a) are opposed to the flying path. The light projecting optical fiber 24 and the light receiving optical fiber 25 are provided. The light projecting optical fiber 24 and the light receiving optical fiber 25 are adjacent edge portions 24b and 25b which are edge portions on the side adjacent to the other optical fiber of the end faces, and anti-adjacent edge portions 24c which are opposite edge portions thereof. 25c is formed in a plane, and is an angle formed by one adjacent edge of the light projecting optical fiber 24 and the light receiving optical fiber 25 and the other non-adjacent edge of the light projecting optical fiber 24 and the light receiving optical fiber 25. Was set so that at least one of the boundaries of the two detection areas would match. Therefore, as compared with the conventional case, the overlapping range of the detection areas of the light projecting optical fiber 24 and the light receiving optical fiber 25 is increased, and the detection areas can be made coincident with each other in the upper part of the flight path where the weft presence frequency is relatively high. As a result, the flying weft detection performance can be improved.

  (2) The support member 22 is provided so as to be able to enter and exit the opening of the warp T from between the warp T rows, and the light projecting optical fiber 24 and the light receiving optical fiber 25 have guide recesses 15 a formed in the wings 15. The end surfaces (tip surfaces 24a, 25a) are arranged in a vertically aligned state. In this configuration, the light receiving optical fiber 25 receives the reflected light projected from the light projecting optical fiber 24 and reflected by the guide recess 15a, so that the weft is detected by the reflected light reflected by the weft. Detection accuracy is increased. Further, the thickness of the support member 22 can be reduced compared to the configuration in which the end faces of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged side by side, and the resistance when the support member 22 enters and exits the warp T opening is small. Become.

  (3) The light projecting optical fiber 24 and the light receiving optical fiber 25 are formed such that the end surfaces (tip surfaces 24a, 25a) are inclined with respect to a plane orthogonal to the axial direction of each optical fiber. According to this configuration, the angle formed by the end surface with the plane perpendicular to the axial direction of the optical fiber is reduced as compared with the case where only the end surface of one optical fiber is inclined with respect to the plane perpendicular to the axial direction of the optical fiber. be able to.

  (4) In the light projecting optical fiber 24 and the light receiving optical fiber 25, the adjacent edge portions 24b and 25b and the anti-adjacent edge portions 24c and 25c constituting the front end surfaces 24a and 25a make a certain angle with the axial direction of the optical fiber. It is formed so as to constitute one plane. Therefore, the processing of the front end surfaces 24a and 25a is facilitated as compared to the case where the adjacent edge portions 24b and 25b and the anti-adjacent edge portions 24c and 25c are configured by a plurality of planes that form angles different from the axial direction of the optical fiber.

  (5) The light projecting optical fiber 24 and the light receiving optical fiber 25 are each composed of a multi-optical fiber in which a plurality of fiber elements 26 are bundled. Therefore, the detection sensitivity is higher than that of a single optical fiber.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. The weft detection device of this embodiment does not detect the wefts that fly in the inner cage passage 16 that constitutes the flight path, but the position where the front ends of the wefts correspond to the discarded ears of the woven fabric, that is, the weft insertion end This is different from the first embodiment in that it is used to detect whether or not it has reached. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 1, the weft sensor 30 constituting the weft detection device is fixed to a weft arrival position where the weft reaches outside the opening of the warp T via a support block 31 so that the position can be adjusted.

  As shown in FIG. 7, the weft sensor 30 includes a support member 32 such that the light projecting optical fiber 24 and the light receiving optical fiber 25 are aligned along the weft insertion direction (left-right direction in FIG. 7). It is provided in a supported state. The weft sensor 30 is provided at a position facing the flying wing 15 and the flight path of the weft Y. The light projecting optical fiber 24 and the light receiving optical fiber 25 are constituted by multi-optical fibers in which a plurality of fiber elements 26 (not shown) are bundled.

  The light projecting optical fiber 24 is provided on the upstream side in the flying direction of the weft Y, and the light receiving optical fiber 25 is provided on the downstream side in the flying direction of the weft Y. The light projecting optical fiber 24 and the light receiving optical fiber 25 are formed such that tip surfaces 24a and 25a are inclined with respect to a plane orthogonal to the axial direction of each optical fiber. The angle of inclination of each of the front end surfaces 24 a and 25 a is set to an angle that increases the degree of overlap between the light projecting range of the light projecting optical fiber 24 and the light receiving range of the light receiving optical fiber 25. When the light projected from the light projecting optical fiber 24 is reflected by the weft Y, the reflected light is incident on the front end surface 25 a of the light receiving optical fiber 25.

  The optical axes of the light projecting optical fiber 24 and the light receiving optical fiber 25 are substantially orthogonal to the weft insertion direction. The portion C where the anti-light receiving optical fiber side line indicating the light projecting range of the light projecting optical fiber 24 and the line L2 extending parallel to the back surface of the wing 15 and extending in the weft insertion direction intersects is received by the light receiving optical fiber 25. This coincides with the point where the line on the light projecting optical fiber side indicating the range and the line L2 intersect. The light receiving range of the light receiving optical fiber 25 is a portion D where a line on the light receiving optical fiber side indicating the light projecting range of the light projecting optical fiber 24 and a line L2 extending parallel to the back surface of the wing 15 and extending in the weft insertion direction. This coincides with the point where the line on the side of the optical fiber for anti-projection and L2 intersects. In FIG. 7, on the wing 15 side from the line L <b> 2, an extension portion of a line on the side of the light receiving optical fiber that indicates the light projecting range of the light projecting optical fiber 24 and a light projecting that indicates the light receiving range of the light receiving optical fiber 25 A portion with a dot surrounded by an extension of the line on the optical fiber side is a detection area A. That is, even if the shape of the end faces of the light projecting optical fiber 24 and the light receiving optical fiber 25 of the weft sensor 30 is the same as that of the first embodiment, the locations C and D that are the boundary between them coincide.

According to this embodiment, in addition to the same effects as (3), (4), and (5) of the first embodiment, the following effects can be obtained.
(6) The support member 32 is provided at the weft arrival position where the weft reaches outside the opening of the warp T, and the light projecting optical fiber 24 and the light receiving optical fiber 25 have their front end surfaces 24a and 25a aligned in the weft insertion direction. It is provided as follows. Therefore, unlike the conventional weft detection device for detecting the weft insertion end, no lens is used for the light projecting unit and the light receiving unit, so the width of the device (weft sensor 30) (size in the direction parallel to the weft insertion direction) Becomes smaller. As a result, in the conventional weft detection device for detecting the weft insertion end using lenses in the light projecting unit and the light receiving unit, the width of the device is more than a dozen mm, whereas the light projecting optical fiber 24 and the light receiving optical fiber If the diameter of 25 is 2 mm or less, the weft sensor 30 having a significantly narrow width (for example, 5 mm or less) can be configured. Therefore, the length of the weft necessary for weft insertion can be reduced.

The embodiment is not limited to the above, and may be embodied as follows, for example.
The tip surfaces 24a and 25a of both the light projecting optical fiber 24 and the light receiving optical fiber 25 do not need to be inclined with respect to a plane perpendicular to the axial direction of the optical fiber. For example, as shown in FIG. 8A, in the configuration in which the tip surfaces 24a and 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged vertically, the tip surface 24a is orthogonal to the axial direction of the optical fiber. The tip surface 25a may be formed to be inclined with respect to a plane orthogonal to the axial direction of the optical fiber.

  As shown in FIG. 8B, in the configuration in which the tip surfaces 24a and 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged vertically, the tip surface 24a is orthogonal to the axial direction of the optical fiber. The tip surface 25a may be formed in parallel to a plane orthogonal to the axial direction of the optical fiber.

  As shown in FIG. 8C, in the configuration in which the tip surfaces 24a and 25a are arranged vertically, the tip surface 24a is formed in parallel to a plane perpendicular to the axial direction of the optical fiber, and the tip surface 25a is The adjacent edge portion 25b may be formed parallel to a plane orthogonal to the axial direction of the optical fiber, and the anti-adjacent edge portion 25c may be formed inclined with respect to a plane orthogonal to the axial direction of the optical fiber.

  As shown in FIG. 8D, in the configuration in which the tip surfaces 24a and 25a are arranged vertically, the tip surface 25a is formed in parallel with a plane perpendicular to the axial direction of the optical fiber, and the tip surface 24a is The adjacent edge portion 24b may be formed in parallel with a plane orthogonal to the axial direction of the optical fiber, and the anti-adjacent edge portion 24c may be formed inclined with respect to a plane orthogonal to the axial direction of the optical fiber.

  As shown in FIG. 9A, in the configuration in which the tip surfaces 24a and 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged side by side, the tip surface 24a is orthogonal to the axial direction of the optical fiber. The tip surface 25a may be formed in parallel to a plane perpendicular to the axial direction of the optical fiber.

  As shown in FIG. 9B, in the configuration in which the tip surfaces 24a and 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged side by side, the tip surface 24a is orthogonal to the axial direction of the optical fiber. The tip surface 25a may be formed to be inclined with respect to a plane orthogonal to the axial direction of the optical fiber.

  In the configuration in which the end surfaces 24a and 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged side by side, one end surface 24a formed to be inclined with respect to a plane perpendicular to the axial direction of the optical fiber. (Or the front end surface 25a) may be formed by inclining only the anti-adjacent edge 24c (or the anti-adjacent edge 25c) of the front end surface.

  In the configuration in which the end surfaces 24a, 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged vertically, the light projecting optical fiber 24 24a is disposed on the lower side and the light receiving optical fiber 25 has the front end surface 25a on the upper side. You may arrange in.

  In the configuration in which the end surfaces 24a and 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged side by side, the light projecting optical fiber 24a is disposed on the opposite side of the weft insertion side, and the light receiving optical fiber 25 has a front end surface 25a. May be arranged on the weft insertion side.

  The light projecting optical fiber 24 and the light receiving optical fiber 25 are arranged between the adjacent edge portions 24b and 25b and the anti-adjacent edge portions 24c and 25c in a configuration in which the adjacent edge portions 24b and 25b and the anti-adjacent edge portions 24c and 25c are bent. Further, a plane inclined with respect to the adjacent edge portions 24b and 25b and the anti-adjacent edge portions 24c and 25c may be provided.

  When the front end surfaces 24a and 25a of the light projecting optical fiber 24 and the light receiving optical fiber 25 are formed to be inclined with respect to a plane perpendicular to the axial direction of the optical fiber, the inclinations of the front end surfaces 24a and 25a may be different.

  The angle θ formed by the adjacent edge portion 25b of the light receiving optical fiber 25 and the non-adjacent edge portion 24c of the light projecting optical fiber 24 is added to the light projecting optical fiber side boundary of both detection areas, and the light receiving optical fiber side boundary May also be set to match. The light receiving optical fiber side boundary between the two detection areas refers to the lower line Ls indicating the light projection range and the lower jaw portion corresponding to the guide recess 15a of the wing 15 in FIGS. 6 (a) and 6 (b). It means a location D where the back surface of the wing 15 and a parallel tangent L1 intersect.

  The light projecting optical fiber 24 and the light receiving optical fiber 25 may be connected to the LED or the PD without using a plastic fiber. However, the configuration connected via the plastic fiber is more effective in avoiding the damage of the optical fiber due to the beating motion of the loom.

  θ: angle, A: detection area, T: warp, Y: weft, 14: sley, 15 ... wing, 15a ... guide recess, 22, 32 ... support member, 24 ... light emitting optical fiber, adjacent edge 24b, 25b, anti-adjacent edges 24c, 25c, 25...

Claims (4)

In the weft detection device in the air jet loom where wefts are inserted by jetting compressed air and the wefts inserted are beaten by the wings on the sley,
A support member disposed to face the flying path of the weft,
A light-emitting optical fiber and a light-receiving optical fiber provided in the support member and having an end face opposed to the flight path;
The light projecting optical fiber and the light receiving optical fiber are formed in a plane in which the adjacent edge, which is the edge adjacent to the other optical fiber, of the end face and the opposite edge, which is the opposite edge, are formed in a plane. And detecting an angle formed by the adjacent edge of one of the light projecting optical fiber and the light receiving optical fiber and the other non-adjacent edge of the light projecting optical fiber and the light receiving optical fiber. An apparatus for detecting a weft in an air jet loom, wherein at least one of the boundaries of an area is set so as to fit the flight path .   The support member is provided so as to be able to enter / exit into the warp opening from between the warp rows, and the light projecting optical fiber and the light receiving optical fiber are directed to the guide recesses formed in the wings in the state where the end surface is oriented The weft detection device in an air jet loom according to claim 1, wherein the wefts are arranged vertically.   The support member is provided at a weft arrival position where the weft reaches outside the opening of the warp, and the light projecting optical fiber and the light receiving optical fiber are provided such that the end faces are aligned along the weft insertion direction. Item 2. A weft detection device in an air jet loom according to item 1.   The air according to any one of claims 1 to 3, wherein each of the light projecting optical fiber and the light receiving optical fiber is formed such that the plane is inclined with respect to a plane orthogonal to the axial direction of each optical fiber. Weft detection device in jet loom.