BE1023209A1 - Device for detecting a weft yarn in a jet-type loom - Google Patents

Abstract

A weft yarn detecting device in a jet type loom which injects a fluid jet to insert a weft yarn through a shedding formed by an upper warp yarn and a lower warp yarn and which then uses a comb provided on a rot to push the weft yarn for smoothing the fabric, which includes a weft yarn sensor projecting and receiving light over the width of the fabric so as to face the flight passage of the weft yarn. The weft detector has a detection zone having a light producing area and a light receiving area.

When the loom is in an angular position in which the leading end of the weft thread reaches the detection zone, the upper warp yarn and the lower warp yarn are disposed outside the detection zone and at least one area selected from the light projection area and the light receiving area is disposed in the shed.

Description

DEVICE FOR DETECTING A FRAME WIRE IN A TRADE MACHINE

JET TYPE WEAVING

BASIS OF THE INVENTION

The present invention relates to a device for detecting a weft yarn in a jet-type loom, wherein a weft yarn is inserted by a fluid jet and the inserted weft yarn is beaten by a comb provided on a rot of the jet-type loom.

The quality of a woven fabric largely depends on the flight conditions of the weft yarn. Japanese Unexamined Patent Application Publication No. 2010-209478 discloses a weft yarn detecting device having a light-transmitting optical fiber and a light-receiving optical fiber both of which are provided. on a member acting as a support that moves inside and outside a crowd formed between warp threads. Referring to FIG. 6, in which the weft yarn detection device of the publication cited above is shown, the support member 51 of the weft yarn detection device is disposed in such an orientation as its pointed end faces the flight passage 53 for the weft thread (the weft yarn not being shown in the figure), which is formed by the guiding recesses 2A of several comb blades 52. As it is 7A and 7B, the support member 51 is formed by a pair of body halves 51A and 51B which are connected to each other, and the optical fiber projecting light 54 and the fiber Light-receiving optics 55 are exposed through an aperture 51C formed at the tip end of the support member 51. Each of the optical fibers 54 and 55 is comprised of a multimode optical fiber including a plurality of d-shaped elements. e fibers in the form of a beam. The end portion 56 of the support member 51 and the end surfaces of the optical fibers 54 and 55 are made with a smooth surface forming a convex curve, so that we obtain a detection of a weft yarn in the process of to fly without causing any damage to the warp threads.

The support member 51 is made to be thin enough to pass through a series of warp threads and therefore the dimension (or diameter) of the optical fiber projecting light 54 and optical fiber receiving light. which are mounted in the thin support member 51 is restricted by the size (or thickness) of the support member 51.

Referring to FIGS. 8A and 8B, in which we see a weft yarn detecting device which is revealed in the application indicated above, a light projection zone Al (or a detection zone) and a light receiving zone A2 (or a detection zone) are present in the flight passage 53 which is provided at the rear of an imaginary tangential line L1 which is parallel to the rear surface of the reign blade 52 and also tangential to the lower jaw portion 52B of the comb blade 52.

The weft detection device transmits a detection signal when it detects any wire present in the superimposed area between the projection area of the light A1 and the light receiving area A2, without taking into account the fact of whether it is a weft yarn or a warp yarn. Therefore, defection of the weft yarn must be carried out in a state in which no warp yarn is present in the superimposed area between the light projection area A1 and the light receiving area A2.

In the weft defection device in accordance with Japanese Unexamined Patent Application Publication No. 2010-209478, wherein there is a risk of detecting a warp yarn in the state in which a yarn chain is present in the superimposed zone in the guide recess 52A between the projection area of the light A1 and the light receiving area A2. Accordingly, a flying weft yarn must be detected when the loom is in an angular position such that no warp is present in the superimposed area in the guide recess 52A between the zone. for projecting the light A1 and the light-receiving area A2 (for example at an angle of 96 ° or more). In other words, the weft yarn can not be detected for a period of time that has elapsed since the start of inserting the weft yarn, i.e. the beginning of the injection by the main nozzle until a moment at which the 96 ° angular position is reached by the loom. It should be pointed out that the letter T in FIGS. 8A and 88 denotes the upper weft yarn when the loom forms an angle of 96 ° with respect to its angular position.

The present invention, whose starting point is none other than the above-mentioned problem, relates to a weft detection device including a light-transmitting and light-receiving weft detector which is movable so as to being able to enter and exit the warp-formed shed and enlarge the detectable range of the weft yarn towards the main loom nozzle relative to the prior art weft detection device.

SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a weft yarn detection device is provided in a jet type loom which injects a jet of fluid to insert a weft yarn through a warp-shaped shed. upper and lower warp yarn which then uses a comb provided on a bur to push the weft yarn for weaving of the fabric The weft yarn detecting device includes a weft yarn detector projecting and receiving yarn The weft detector has a detection zone having a light producing area and a light receiving area. When the loom is in an angular position in which the leading end of the weft thread reaches the detection zone, the upper warp yarn and the lower warp yarn are arranged s outside the detection zone and at least one zone selected from the light projection area and the light receiving area is disposed in the shed. In this case, the detection zone refers to an area in the flight passage of the weft yarn occupied by the light projected by the optical fiber of the weft detector, projecting light, in the case of the fiber optical projecting light and an area in the flight passage of the weft thread occupied by the light that can be received in the case of optical fiber receiving light. Other aspects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings which illustrate by way of example the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view schematically showing an air jet type loom having a weft insertion device and a weft detection device in accordance with a form of embodiment of the present invention.

FIG. 2 is a partially cutaway side view in which the positional relationship between a comb blade and a weft sensor of the weft detection device of FIG. 1 is schematically represented.

FIG. 3A is a schematic view in which a light projection area of the weft detector of FIG. 2 is shown.

FIG. 3B is a schematic view in which a light receiving area of the weft detector of FIG. 2 is shown.

FIG. 4A is a partially cutaway cross-sectional side view showing the weft detector of FIG. 2.

Fig. 4B is a partially enlarged view of the weft detector of Fig. 4A.

Fig. 5 is a diagram showing the relationship between detected waveforms of the weft detector and the angular position of the loom.

Fig. 6 is a side view showing the relationship between the weft detector and the comb blade in accordance with the prior art.

Fig. 7A is a front view of the weft detector of Fig. 6.

Fig. 7B is a cross-sectional view taken along the line 1-l of Fig. 7A.

Fig. 8A is a schematic view in which the operation of the weft detector of Fig. 6 is explained; and FIG. 8B is a schematic view in which the operation of the weft detector of FIG. 6 is also explained.

DETAILED DESCRIPTION OF THE EMBODIMENTS

A first embodiment of the present invention which is designed for use in an air jet loom will now be described with reference to Figs. 1-6.

Referring to Figure 1, there is shown the air jet type loom which includes a main nozzle 11 for the insertion of a weft yarn, a plurality of secondary nozzles 12 to support the insertion of the yarn. weft and a comb 13 which is fixed on a rot 14. The comb 13 includes a plurality of comb blades 15 which are arranged in the insertion direction of the weft thread and which each have a guide recess 15A. The guide recess 15A of said plurality of comb blades 15 forms a passage 16 for the weft thread or a passage for the flight of the weft thread. Each secondary nozzle 12 is removably mounted on the rot 14 via a support block 17 so that the position of the secondary nozzle 12 can be adjusted. The secondary nozzles 12 are movable to be able to enter and exit a crowd formed by the warp threads T correspondingly to the oscillation movement of the rot 14.

A plurality of weft detectors 20 that detect a weft yarn Y that is flying in the passage 16 for the weft yarn are mounted on the rot 14 via their corresponding support blocks 21 in such a way that the position of the weft detectors respective 20 can be set. The weft detectors 20 are disposed closer to its main nozzle 11 relative to the center of the width of the fabric. The weft detectors 20 are movable into and out of a crowd of the warp yarns correspondingly to the swinging motion of the pad 14. A weft yarn detector (not shown) which detects the arrival of the leading end of a weft yarn inserted at the end of the weft insertion range is mounted on the rot 14 in such a manner that the position of the thread detector frame can be set.

The weft detector 20 is arranged such that the upper warp yarns and the lower warp yarns are disposed outside the detection area of the weft detector 20.

The upper warp yarns are in this case the warp yarns which are located above the guide recess ISA, and the lower warp yarns are in this case the warp yarns which are located below the warp thread. guide recess 1 SA.

Hereinafter, the weft detector 20 will be described.

As shown in Figure 2, the weft sensor 20 includes a rod-shaped support member 22 which is attached to the support block 21 which in turn is attached to the rot 14. An end of the member serving as a carrier 22 is movable to enter and exit a shed formed between the T-warp yarns. As was the case in the weft detection device of the unexamined Japanese Patent Application Publication No. 2010 -209478, the support member 22 includes a pair of body halves 22A and 22B which are connected to each other. As shown in Figs. 4A and 4B, a gap 23 is formed between the body halves 22A and 22B (only half body 22A being shown in Fig. 4). It should be pointed out that the support member 22 may be embodied as a single cylindrical body. A light-emitting optical fiber 24 and a light-receiving optical fiber 25 are inserted into the gap 23 of the support member 22. The optical fiber projecting light 24 and the optical fiber receiving light 25 are disposed in the support member 22 in an arrangement such that the end surface 24A of the light-emitting optical fiber 24 and the end surface 25A of the light-receiving optical fiber are arranged one above the other. other and also in an arrangement such that the end surfaces 24A and 25A are oriented towards the guide recesses 15A formed in the comb blades 15. Specifically, the optical fiber projecting light 24 and the receiving optical fiber 25 are arranged in such a way that their end surfaces 24A and 25A face the flight passage (that is to say the passage taken by the weft thread 16). In the first embodiment, the optical fiber for projecting the light 24 is generally disposed above the optical fiber 25 for receiving light.

A light projection member and a light receiving member are mounted in a stationary portion (not shown) which remains static with respect to the oscillation movement of the rot 14. The optical fiber for projecting the light 24 is connected to the light projection element via an optical fiber made in the form of a plastic fiber. A light emitting diode (LED) is used to act as the light projection element. The light-receiving optical fiber 25 is connected to the light-receiving element via an optical fiber made in the form of a plastic fiber. A photodiode (PD) is used to act as the light receiving element.

The light received by the terminal surface 25A of the light receiving optical fiber 25 is transmitted via the light receiving optical fiber 25 to the photodiode (not shown), and the photodiode then transmits to a controller (not shown). an electrical signal as a function of the intensity of the light received. In the controller, a determination is made as to whether a Y-frame wire is present or not based on the input of the electrical signal in the controller. The weft detectors 20, the plastic fibers, the light projecting element, the light receiving element and the controller together form the weft detection device.

As shown in FIG. 4B, each of the fibers, namely the optical fiber projecting light 24 and the optical fiber receiving light 25, represents a multimode optical fiber that is obtained by forming a beam with several elements 26 under the form of fibers. For ease of explanation, the optical fiber projecting light 24 and the light receiving optical fiber 25 are illustrated as a single optical fiber in Fig. 2 and Fig. 4A. In the following description, the optical fiber projecting light 24 and the optical fiber receiving light 25 will be represented as a single optical fiber as appropriate. In the first embodiment, the fiber-like elements 26 represent a multimode fiber SI constituted by glass fibers.

As shown in FIG. 4B, the end surfaces 24A and 25A of the optical fiber projecting light 24 and the light receiving optical fiber 25 are made to provide a single flat surface, respectively.

Each weft detector 20 is arranged in such a way that at ία times the light projection area and the light receiving area of the weft detector 20 are arranged in a host of warp yarns. when the loom is in an angular position at which the leading end of the inserted weft yarn Y reaches the detection zone of the weft detector 20,

Specifically, as shown in FIGS. 3A and 3B, the angle formed by the end surface 25A of the light-receiving optical fiber 25 and the end surface 24A of the light-projecting optical fiber 24 is adjusted in such a way that that the upper limit of the projection area of the light A1 of the optical fiber projecting light 24 and the upper limit of the light receiving area A2 of the light-receiving optical fiber 25 coincide with each other. 'other. In the present embodiment, the end surface 24A of the optical fiber projecting light and the end surface 25A of the optical fiber receiving light are made to form an angle with respect to an imaginary plane H which is perpendicular to the axes of the optical fibers 24, 25 as shown in FIG. 4B. The angle formed between the plane H and each of the end surfaces 24A, 25A is adjusted for example to a value of approximately 10 °. The angle β formed by the axes of the optical fiber projecting light 24 and optical fiber receiving light 25 extending from their ends and a tangential line L1 which is parallel to the rear surface of the blade comb 15 and also tangential to the lower jaw portion 15B of the comb blade 15 is set to a value of approximately 55 °.

The operation of the weft detection device configured as described above will now be described.

Light is projected from the optical fiber projecting light 24 from the weft detector 20 towards the passage of weft thread 16 (the flight passage) through the end surface 24A of the optical fiber projecting. the lumen 24 and a part of the light which is reflected by the guide recess 15A or by a weft yarn Y is received by the end surface 25A of the optical fiber receiving light 25. The light received by the terminal surface 25A of the optical fiber receiving light 25 is transmitted via the optical fiber receiving light 25 to a photoelectric converter (not shown). The photoelectric converter generates an electrical signal that is based on the intensity of the received light and sends the electrical signal to a controller (not shown). The controller then makes a determination as to whether the weft detector 20 has detected the weft yarn Y or not based on the electrical signal. When no weft yarn Y is detected within a predetermined period of time following the start of the injection by the main nozzle Π, the controller determines a failure in the insertion of weft yarn and consequently stops the operation of the loom. When a Y-frame yarn is detected in the predetermined time period in question, the controller adjusts the timing of the injection and the duration of the injection based on the moment of detection at which the leading end of the yarn weft Y is detected and on the angular position of the loom at the moment of detection of the yarn Y.

FIG. 5 shows the waveforms detected by the prior art weft detector and the weft detector 20 of the present embodiment. In FIG. 5, the solid line represents the signal detected by the weft detector 20 and the line formed by a two-dot chain represents the signal detected by the prior art weft detector. As shown in FIG. 5, the interval for the transmission of the reference signal SI of the weave wizard corresponds to a rotation of the loom, that is to say 360 °. In the case of the prior art weft sensor, during the transmission interval or rotation of the loom, the detection signal is emitted when the angular position of the loom 96 ° or less and 250 ° or more. On the other hand, in the case of the weft detector 20 of the present embodiment, the detection signal is emitted when the angular position of the loom is 80 ° or less and 250 ° or more,

Based on the comparison between the prior art weft detector and the sensor of the prior art. in the present embodiment, in the case of the prior art weft detector, as can be seen in the cross-sectional view of FIG. 8B, the light receiving area is adjacent to the portion 52C corresponding to the upper jaw of the comb blade 52 and on the opposite side to the rear surface of the comb blade 52 through the intersection between the portion 52C corresponding to the upper jaw of the comb blade 52 and the tangential line L1 which is parallel to the rear surface of the comb blade 52 and which is also tangential to the portion 52B corresponding to the lower jaw of the comb blade 52. Moreover, in the case of the weft detector 20, as can be seen in the cross-sectional view of FIG. 3B, the light-receiving zone is not adjacent to the portion 15C corresponding to the upper jaw of the comb blade 15 and on the opposite side to the rear surface of the comb blade 15 through the intersection between the portion 15C corresponding to the upper jaw of the comb blade 15 and the tangential line L1 which is parallel to the rear surface of the zone comb 15 and which is also tangential to the portion 15B corresponding to the lower jaw of the comb blade 15.

In addition, as can be seen in FIGS. 3A and 3B, the intersection between the portion 15C corresponding to the upper jaw and the tangential line L1 which is parallel to the rear surface of the comb blade 15 and which is also tangential. at the portion 15B corresponding to the lower jaw which is parallel to the rear surface of the comb blade 15 is adjacent to the portion 15C corresponding to the upper jaw and is also located between the position of the upper warp threads T (Tl) which form a host of warp yarns when the loom is in an angular position of 80 ° and the position of the upper warp yarns T (T2) which form a host of warp yarns when the loom is in a angular position of 96 °. Therefore, the angular position of the 80 ° loom corresponds to a limit at which the shedding upper chain wires T are not detected. In contrast, in the case of the prior art weft detector, the angular position of the 96 ° loom corresponds to a limit at which the shedding upper warp T yarns are not detected.

To put it another way, with the prior art weft sensor, the position of the weft yarn can not be detected during the rotation of the loom since the start of the thread insertion. weft to the 96 ° angular position of the loom, since warp yarns are detected in this range of the angular position of the loom, i.e., the moment corresponding to the loom. arrival of the weft yarn Y can not be detected in said range. On the other hand, in the case of the weft detector 20, even if the moment corresponding to the arrival of the weft yarn can not be detected, as is the case for the prior art weft detector during the rotation of the loom from the start of inserting the weft yarn to the 80 ° angular position of the loom, the weft yarn can be detected during rotation of the loom at an angular position which is greater than 80 °. Therefore, in the case of the weft detector 20, the range in which the flying weft yarn can be detected can be widened towards the main nozzle 11, when compared to the yarn detector 11. weft of the prior art. The flight distance of the weft yarn during rotation of the loom from the angular position of 80 ° to the angular position of 96 ° is for example 16 cm in the case of the loom having a width of 2 m and 32 cm in the case of the loom with a width of 4 m. It should be noted that the distance may vary according to the conditions of commissioning of the loom.

According to the present embodiment, the effects indicated below are obtained. (1) The weft yarn detection device is designed for use in a jet-type weaving machine in which a weft yarn Y is inserted by a fluid jet and beaten or pushed by a comb 13 provided on a The weft detecfion device includes at least one weft projecting and receiving weft detector, which is disposed across the width of a fabric so as to face the flight passage (the passageway). weft yarn 16) of the weft Y yarn, the upper warp yarns and the lower warp yarns being arranged outside the detection zone of the weft yarn detector 20. At the same time the light production zone Al and the light receiving zone A2 of the weft detector 20 are arranged in a host of warp yarns which are obtained when the loom is in an angular position at which the front end of the yarn Y frame arrives in the zon detection of the weft detector 20.

In accordance with the configuration in which the upper warp yarns and the lower warp yarns are arranged outside the detection zone and in which both the Al light projection area and the A2 light receiving area of the weft detector 20 are arranged in a host of warp yarns when the loom is in an angular position at which the leading end of the weft yarn inserted by the jet of fluid reaches the detection zone of the yarn. in the weft detector 20, no warp thread T is detected by the weft detector 20 when the weft detector 20 detects the weft yarn Y. Therefore, the range in which the weft yarn stealing can be detected by the weft detector 20 which moves to enter and exit the crowd of warp yarns is widened towards the main nozzle 11 of the loom to weave. Further, even if no warp thread T is detected by the weft detector 20 as long as at least the light projection area A1 and the light receiving area A2 are located in the crowd of warp yarn, the weft yarn detector which both at the light projection area Al and the light receiving area A2 are located in the shed son of chains is easier to manufacture and reduces the number false detections. (2) At least one weft detector 20 is disposed at a location which is closer to the main nozzle 11 relative to the center of the width of the fabric. A fluid injected by the secondary nozzles 12, in addition to the fluid injected by the main nozzle 11, is also used for the theft of weft yarn Y. The provision of the weft detector 20 at a location which is closer of the main nozzle 11 relative to the center of the width of the fabric detects a frame wire insertion failure at an earlier time than the case in which the weft detector 20 is disposed closer the opposite side to the main nozzle 11 relative to the center of the width of the fabric, which saves the fluid injected by the secondary nozzles 12. (3) The use of optical fiber light projection 24 and the light-receiving optical fiber 25 consisting of multi-mode optical fibers obtained from the formation of a bundle containing a plurality of fiber-shaped elements 26 facilitates the increase of the precision. detection direction of the weft detector 20 with respect to the case in which each of the optical fibers, namely the light-projection optical fiber 24 and the light-receiving optical fiber 25, is made in the form of a unique optical fiber.

The present invention is not limited to the above-mentioned embodiment and can be modified as follows.

In accordance with the present invention, the weft detector 20 may be configured such that, not both the light projection area A1 and the light receiving area A2, but at least one of said areas that is, the light projection area A1 and the light receiving area A2 is located in the shed of warp yarns at an angular position of the loom to which the leading end of the weft yarn Y reaches in the detection zone of the weft sensor 20. For example, only Ια light projection zone A1 can be arranged in the shed of warp yarns at an angular position of the loom to which the front end of the yarn weft Y arrives in the detection zone of the weft detector 20, or only the light detection zone A2 can be arranged in the shed of warp yarns at an angular position of the loom to which the leading end of the weft yarn Y reaches the detection zone of the weft detector 20.

The projection area of the light A1 of the light-emitting optical fiber 24 and the light-receiving area A2 of the light-receiving optical fiber 25 need not necessarily cover the entire area at the back of the light-receiving optical fiber 25. intersection between the portion 15C corresponding to the upper jaw and the tangential line L1 which is parallel to the rear surface of the comb blade 15 and which is also tangential to the portion 15B corresponding to the lower jaw. For example, in the case where the area in which the light can not be received is disposed near the portion 15C corresponding to the upper jaw and rear of the intersection between the tangential line L1 and the corresponding portion 15C in the upper jaw, the configuration may be such that the controller makes a determination as to whether or not a yarn Y is present based on detection signals from the weft detector 20 in a state in which said area in which no light is received is disposed outside the crowd of warp yarns. Both the end surface 24A of the optical fiber projecting light 24 and the end surface 25A of the optical fiber receiving light 25 need not necessarily be made to form an angle with respect to the imaginary plane H which is perpendicular to the axes of the optical fibers 24, 25. For example, its configuration may be such that one or other of the end surfaces 24A, 25A is disposed parallel to the imaginary plane H which is perpendicular to the axes of the optical fibers 24, 25 the other end surface of the end surfaces 24A, 25A being made to form an angle with respect to the plane H.

The end surface 24A of the light-emitting optical fiber 24 and the end surface 25A of the light-receiving optical fiber 25 need not be in the form of a single flat surface, respectively, several continuous planes capable of forming the end surfaces 24A, 25A.

The end surface 24A of the light-emitting optical fiber 24 and the end surface 25A of the light-receiving optical fiber 25 need not be in the form of one or more flat surfaces, continuous curved surfaces, or combination of continuous curved surfaces and flat surfaces capable of forming the end surfaces 24A, 25A.

The end surface 25A of the light-receiving optical fiber 25 may be disposed above the end surface 24A of the optical fiber projecting light 24.

The end surface 24A of the optical fiber projecting light 24 and Ια end surface 25A of the optical fiber receiving light 25 can be made to form different angles with respect to the imaginary plane H which is perpendicular to the axes of the optical fibers 24 , 25.

The light-emitting optical fiber 24 and the light-receiving optical fiber 25 may be directly connected to the light-emitting diode or photodiode without using plastic fibers therebetween. It should be noted however that the use of plastic fibers and effective to prevent degradation of optical fibers caused by the heat due to the comb.

The weft detector 20 may be configured in such a way that the light-projection element of the light-receiving element is provided at the pointed end of the support member 22 without using the optical fiber projecting from it. the light 24 and the optical fiber receiving the light 25.

Claims (3)

A weft yarn detecting device in a jet type loom which injects a fluid jet to insert a weft yarn (Y) through a shedding formed by an upper warp yarn (T) and a yarn of lower chain (T) ef which then uses a comb (13) provided on a rot (14) to push the frame wire (Y) for weaving a fabric, the weft detection device comprising a detector light-transmitting and receiving weft yarn (20) disposed across the width of the fabric so as to face the weft passage (16) of the weft yarn (Y), characterized in that the yarn frame (20) has a detection area (A1, A2) having a light generating area (A1) and a light receiving area (A2); and when the loom is in an angular position in which the leading end of the weft yarn (Y) reaches the detection zone (A1, A2), the upper warp (T) and the warp yarn (T) are arranged outside the detection zone (A1, A2) and at least one of the light projection zone (A1) and the light receiving zone (A2) are arranged in the crowd. A weft yarn detecting device according to claim 1, characterized in that the weft yarn sensor (20) is disposed closer to the main loom nozzle (11) relative to the center of the width of the yarn. the stuff. A weft defecfion device according to claim 1 or 2, characterized in that both the light projection area (A1) and the light receiving area (A2) of the weft (20) are arranged in the crowd of warp threads (T).