JPH0791737B2 - Weft detection device for jet turm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a weft detection device in a jet loom.

(Prior Art) Generally, in a jet loom, a weft yarn supplied by a length measuring device into a warp yarn opening by a main nozzle is guided by a large number of thin weft guide members arranged in rows on a sley. The weft is inserted in the hole, and is assisted by the injection of the auxiliary nozzle to be pulled in the guide hole. Then, after the weft insertion is completed, the weft yarn is separated from the weft guide passage along with the beating operation and is beaten to the woven fabric. In such a weft insertion method using a jetting fluid, the flying state of the weft has a great influence on the quality of the woven fabric, and the jetting timing and jetting pressure of the auxiliary nozzle must be set reliably. Therefore, it is necessary to search the flight state of the weft,
As a device therefor, there is a weft detecting device disclosed in Japanese Utility Model Publication No. 60-156191. In this device, photoelectric sensors are provided at one point of the guide hole of the weft guide detection member and at the escape opening, respectively, to detect the arrival of the weft tip and the escape of the weft. However, the weft arrival detection area by this sensor is extremely narrow because it is limited to a part of the guide hole.
There is a problem in detection accuracy in detecting the tip of the weft thread that freely travels in the guide hole.

Further, the weft detecting device disclosed in Japanese Patent Laid-Open No. 185477/58 is a photoelectric sensor for detecting the arrival of the front end of the weft by providing a plurality of light projecting portions and light receiving portions over substantially the entire inner end surfaces of both sides of the guide hole of the weft detecting member. I am trying. Although this photoelectric sensor has a wide detection area over almost the entire guide hole, it controls the light projecting section and the light receiving section by providing a number of wires according to the number of the light projecting section and the light receiving section in the thin plate-shaped weft detecting member. There is a limit in terms of wiring space because it needs to be connected to the element.

Further, in the devices disclosed in JP-A-55-142750 and JP-A-52-155261, a pair of light beams facing each other with a slit opening for weft escape formed at the upper part of the guide hole of the weft detection member are sandwiched. The light emitting portion and the light receiving portion are formed of fibers, and the weft yarn passing through the opening is detected. However, in the above-mentioned configuration in which the weft is detected when the weft passes through the opening, the detection timing is slow, and it is difficult to adjust the injection pressure and the injection timing of the auxiliary nozzle according to the passage time of the weft. Further, the detection areas of the light emitting portion and the light receiving portion are limited to a part of the opening and are extremely narrow, and even if these light emitting and receiving portions are attached to the peripheral edge of the guide hole to accelerate the detection timing, the detection accuracy will be improved. There's a problem.

(Problems to be Solved by the Invention) As described above, the present invention solves all of the problems that the detection area is narrow and the detection accuracy is low, and furthermore, the embedment is impossible in the thin weft detection member within the width position of the cloth. It is what

Structure of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, one end of a pair of optical fibers is arranged in the vicinity of a yarn guide hole for guiding a weft, and the same end is further provided. The core portion is exposed and formed in a slant shape, and the projecting side reflecting surface and the light receiving side reflecting surface are formed in the slanted portion.

(Operation) By adopting the above-mentioned means, the present invention allows the light projecting portion formed by a small number of optical fibers to project light over almost the entire area in the vertical direction of the thread guide hole and freely fly in the thread guide hole. The running weft thread passes through the light projection area of the light projecting section. Also, like the light emitting unit, the light receiving unit formed with a small number of lights receives almost all of the light projected from the light emitting unit, and when the weft passes through the yarn guide hole, the amount of received light changes. Detect this.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 3, weft Y drawn from cheese 1.
Is measured and stored by the weft measuring and storing mechanism 2, and every time the weft is inserted, a necessary amount of weft is injected by the jet of the main nozzle 3 toward the weft guide member 5 arranged on the sley 4. It has become. As shown in FIG. 2, between the weft guide members 5 on the sley 4, a proper number of weft detection members 6 and auxiliary nozzles 7 for assisting the weft Y are arranged, and the weft guide members 5 are provided. A weft passage P is formed by the yarn guide holes 8 and 9 of the weft detection member 6.
The weft guide member 5, the weft detection member 6, the auxiliary nozzle 7
Are attached to a plurality of blocks Ba to Bf provided on the upper part of the sley 4, and the auxiliary nozzles 7 of the blocks Ba to Bf are mechanical valves 11a to 11f via fluid passages 10a to 10f provided therein. Is connected to the sub tank 12 and the pressure regulator 13 from the valves 11a to 11f, and joins with the fluid passage 17 extending from the main nozzle 3 through the valve 14, the sub tank 15 and the pressure regulator 16 and then the fluid supply (not shown). Connected to the source.

As shown in FIG. 1, the weft detecting member 6 has a base end portion 18
And a curved portion 19 and a straight portion 20 projecting upward from the curved portion 19 and the straight portion 20. The yarn guide hole 9 surrounded by these three members 18, 19, 20 is provided between the curved portion 19 and the straight portion 20. It communicates with the outside through the slit-shaped thread escape opening 21 formed. An approximately Y-shaped groove 24 is formed in the weft detecting member 6, and communicates with the outside at the base end portion 18 and with the yarn guide hole 9 at the curved portion 19 and the straight portion 20.

In the base end portion 18 of the weft detecting member 6, a pair of optical fiber bundles Fa and Fb guided by a covered wire C from the outside are introduced into the groove 24 in a bound state, one of which is to the curved portion 19 and the other is Straight section 20
The optical fibers 22, 23 gradually extend away from each other in the groove 24 while being separated from each other, and their tips reach the vicinity of the yarn guide hole 9. In particular, as shown in FIG. 4, in the optical fibers 22 and 23, the clad portions 25 and 26 are peeled off at the tip end portions to expose the core portions 27 and 28, and the core portions on the curved portion 19 side and the straight portion 20 side are further exposed. 2
After the entire exposed end portions of 7,28 are obliquely cut so as to face each other, the cut end surfaces are coated with a coating material having a high reflection efficiency to form reflecting surfaces 31,32.
Outside the weft detection member 6, each of the optical fibers 22 and 23 is a light-emitting element formed of a high-intensity LED, a laser, or the like at the other end of the optical fiber 22 on the curved portion 19 side, and the other optical fiber 23 on the straight portion 20 side. The end is connected to a light receiving element such as a photodiode or a phototransistor. A light projecting portion 33 is formed by the core portion 27 exposed on the curved portion 19 side and a light receiving portion 34 is formed by the core portion 28 exposed on the straight portion 20 side in the peripheral edge of the thread guide hole 9.
The light reflected by the reflection surface 31 is provided so as to be projected onto the light receiving portion 34 in a substantially parallel state in the entire vertical direction of the thread guide hole 9. As the coating material, a material having the best reflection efficiency in the wavelength band of the light projecting element serving as the light source of the optical fiber 22 on the light projecting section 33 side is selected, and the cutting angle of the core sections 27, 28 is also reflected. It is set to an optimum value that improves the reflection efficiency of the surfaces 31 and 32.

Further, the optical fiber 23 on the light receiving section 34 side is electrically connected to the control section 36 via the light receiving element, and the control section 36 is electrically connected to the machine base rotation angle detection device 37 and the display device 38. When the light receiving section 34 detects the passage of the weft yarn Y,
A weft detection signal is issued to the control unit 36, and the control unit 36 performs a comparison calculation process between the weft detection signal and the rotation angle detection signal sent from the machine base rotation angle detection device 37, and the weft detection is started from the time the rotation angle detection signal is transmitted. The difference until the signal is transmitted is digitally displayed on the display device 38 in units of rotation angles. The display device 38 may be replaced with an alarm device or a stop device that stops the operation of the device.

In addition, 39 is a reed.

Now, in order to adjust the injection timing and the injection pressure in the auxiliary nozzle 7, the loom is operated on a trial basis. The weft Y, which is pressure-fed by the main nozzle 3 from the weft storage length measuring mechanism 2, flies in the weft passage P of the weft guide member 5. When the tip of the weft Y reaches the inside of the yarn guide hole 9 of the weft detection member 6 of the block Ba and crosses the light projection area of the light projecting unit 33 over almost the entire yarn guide hole 9, the amount of light received by the light receiving unit 34 increases. Decrease. Then, the light receiving unit 34 outputs a detection signal based on the reduction of the received light amount to the control unit 36, and the control unit 36 digitally displays the difference from the rotation angle detection signal transmission time to the weft yarn detection signal transmission time on the display device 38. . After that, the machine base is stopped to release the operational connection between the valve 11a and the machine rotation drive source, and the opening timing is adjusted based on the digital display to adjust the injection timing and the injection pressure of the auxiliary nozzle 7 in the block Ba. . After the adjustment of the injection timing and injection pressure of the auxiliary nozzle 7 in the block Ba is completed, the valve 11a
And the machine base rotary drive source are operatively connected to each other, and the machine frame is operated again to fly the weft Y. Then, in the blocks Bb to Bf, the injection timing of the auxiliary nozzle 7 and the setting of the injection pressure are adjusted by the same procedure.

In the present invention, since the reflecting surfaces 31 and 32 of the core portions 27 and 28 are formed in a slanted shape, their areas are wide. Therefore,
The light projecting area of the light projecting portion 33 and the light receiving area of the light receiving portion 34 become extremely wide, and if the optical fibers 22 and 23 having appropriate diameters are selected according to the size of the guide light 9 of the weft detecting member 6. The light emitting surface 33 and the light receiving portion 34 can be formed by the minimum number of optical fibers 22 and 23, and can be easily embedded in the thin weft detecting member 6 provided in the woven fabric range. You can By adopting the optical fibers 22 and 23 having a large diameter, the light projecting section 33 and the light receiving section 34 are each provided with one optical fiber.
It is also possible to configure with 22,23.

Further, in the optical fibers 22 and 23, light is conducted to the core portion 27 formed in the exposed portion while reflecting inside the core portion 27 covered by the cladding portion 25 on the light projecting portion 33 side. Since the light is reflected by the reflecting surface 31 of the exposed core portion 27 substantially parallel to the light receiving portion 37 side, most of the light emitted by the light projecting portion 33 reaches the light receiving portion 34. Therefore, efficient weft detection is performed.

Further, the optical fiber is weak in bending, and there is a possibility that the optical fiber may be broken in the conventional product in which the tip portions of the pair of optical fibers are bent so that both core portions face each other. However, in the present invention, since the core portions 27 and 28 are formed obliquely at the tips of the optical fibers 22 and 23, it is not necessary to bend the tips of the optical fibers 22 and 23. Therefore, the optical fibers 22 and 23 are extremely unlikely to break.

Further, the weft detecting member 6 of the present invention can be used also as a weft insertion error detection device, and makes the weft insertion error quicker than the conventional weft insertion detector in which the light projecting and receiving parts are opposed to each other with the opening 21 interposed therebetween. , And can be effectively detected.

The present invention is not limited to the above embodiment,
For example, the light emitting unit 33 and the light receiving unit 34 are arranged adjacent to each other, and the thread guide hole 9
When the weft Y reaches the inside, the light projected by the light projecting section 33 is reflected by the weft Y and reaches the light receiving section 34.

A so-called modified reed is provided with a light projecting portion and a light receiving portion having the same configuration as that of the above-mentioned embodiment.

The valves 11a to 11f communicating with the auxiliary nozzle 7 are electromagnetic type instead of mechanical type, and electrically connected to the control unit 36,
The fluid ejection from the auxiliary nozzle 7 is relay-controlled for each block Ba to Bf based on the weft detection operation of the weft detection member 6. According to this structure, the injection timing and the injection pressure of the auxiliary nozzle 7 can be adjusted at any time during the operation of the loom.

As shown in FIGS. 5 (a) and 5 (b), the exposed core portion
The cutting shape of the tips of 27 and 28 is curved, and anti-slopes 31 and 32 are formed on the curved surfaces to change the light reflection angle.

As shown in FIG. 6, the portions of the core portions 27, 28 opposite to the reflecting surfaces 31, 32 are cut off together with the cladding portions 25, 26 at a position lower than the reflecting surfaces 31, 32, and light is cut off from the cut portions. Adjust the amount of reflected light so that it leaks.

As a matter of course, any changes can be made without departing from the spirit of the invention.

As described above in detail, in the present invention, one end of the core portion exposed at the ends of the pair of optical fibers is formed in a slanted shape, and the weft thread passing through the thread guide hole is formed on this slanted surface. By forming the reflecting surfaces of the light projecting portion and the light receiving portion for detection, respectively, the detection area is provided over almost the entire area of the yarn guide hole, and further, it is easily arranged in the thin plate-like weft guide member in the weft width position. It has the excellent effect that it can be installed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a weft detecting member, FIG. 2 is a partially broken perspective view showing an essential part of the weft detecting device, and FIG. 3 is a schematic front view showing the weft detecting device of the present invention together with a weft measuring device. ,
FIG. 4 is a sectional view showing the reflecting surface of the core portion, FIG. 5 (a) is a sectional view showing another example of the core portion, and FIG. 5 (b) is a sectional view taken along the line BB of FIG. 5 (a). FIG. 6 is a sectional view showing another example of the cut state of the core portion. Thread guide hole 9, optical fibers 22,23, reflecting surfaces 31,32, light projecting section 3
3, light receiving section 34.

Claims (1)

[Claims] 1. A pair of optical fibers having one end arranged near a yarn guide hole for guiding a weft, and a core portion at the end is exposed and formed obliquely, and light is projected onto the oblique portion. A weft detection device in a jet loom having a side anti-slope and a light receiving side reflection surface.