JPH05791U - Photoelectric weft detection device for a weaving loom - Google Patents

Abstract

(57) [Summary] [Purpose] When weft insertion is detected by a light emitter and a light receiver that are placed opposite to each other across the detection space, the weft thread is smoothly guided to the detection space without trouble such as sliding contact with the detection member. Raise the level of the obtained weft detection signal sufficiently to enhance the reliability of the weft insertion detection operation. In an air jet loom including a modified reed 4 defining a weft guide groove 41, the projector 1 and the light receiver 2 are separated by a distance larger than a vertical width of a movement locus region G of the weft guide groove 41 during beating. , U-shaped arm 3 fixed to the loom frame 5
The upper and lower split limbs 31 and 32 are spaced apart from each other.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a photoelectric type weft detecting device for an air jet loom, and more specifically, in an air jet loom equipped with a modified reed defining a weft guide groove, a pair of throwing heads spaced apart from each other across a weft flight path is provided. The present invention relates to improvement of a technique for detecting success or failure of weft insertion by blocking an optical path formed between light receivers with a weft.

[0002]

[Prior Art]

 As a technique for detecting the success or failure of the weft insertion by blocking the optical path formed between the light emitter and the light receiver, which are arranged opposite to each other across the weft flight path, by means of the weft, Japanese Patent Publication No. 57-13653. There is known a weft yarn detecting device disclosed in Japanese Patent No. This prior-art technique was applied to a water jet loom, but the distance between the emitter and the receiver was extremely small. That is, the weft yarn is guided to the slit-shaped detection space by the guide surface of the detection member fixed to the front of the reed and widened toward the reed, and the weft yarns are spaced apart from each other at a distance of 2 mm or less with the detection space interposed therebetween. The light receiver detects the success or failure of weft insertion.

Similarly, it is a technique for detecting the success or failure of weft insertion by blocking the optical path formed between a light emitter and a light receiver, which are spaced apart from each other across the weft flight path, by a weft thread. On the contrary, in a loom, the weft detecting device of Japanese Patent Publication No. 51-46189 is cited as a device in which the distance between the throwing device and the light receiving device is considerably large.

[0004]

[Problems to be solved by the device]

 However, in the former prior application technology, a guide surface is required to guide the weft thread into the narrow detection space of the detection member, so the free end of the weft thread slides into contact with the guide surface and escapes. There is a problem that the detection device is not properly guided to the detection space and causes a malfunction of the detection device. The latter prior art is desirable in that the weft does not slide on the detection member, but the signal level itself of the weft detection signal becomes low because the distance between the light emitter and the light receiver is too large. However, there is a problem in that the amount of deviation of the optical axis due to the vibration of the loom becomes large, which causes the weft detection device to malfunction. In either case, the operational reliability of the weft detection device is impaired.

The object of the present invention is to smoothly guide the weft thread to the detection space without any troubles such as sliding contact with the detection member when detecting the weft insertion by the throwing and light receiving devices which are arranged opposite to each other across the detection space. The purpose of this is to raise the level of the obtained weft detection signal to a sufficiently high level, thereby improving the reliability of the weft insertion detection operation.

[0006]

[Means for Solving the Problems]

 Therefore, in this invention, in an air jet loom equipped with a deformed reed that defines the weft guide groove, the projector and the receiver are projected at a distance larger than the vertical width of the movement trajectory region of the weft guide groove during beating. The main point is that they are separated from each other.

[0007]

[Action]

 At the end of weft insertion, the tip of the weft thread that has reached the anti-feeding side moves in the weaving direction due to the beating motion. At this time, the weft that moves while being regulated in the weft guide groove of the reed is reliably guided between the throwing and receiving units without sliding contact with any of the throwing unit, the receiving unit, and the feeler. Moreover, since the throwing and receiving devices are spaced apart from each other so as to sandwich the movement locus of the weft guide groove, the weft detecting signal obtained by crossing the optical path formed between the sending and receiving devices. Is also a sufficiently high level.

[0008]

【Example】

 1 and 2 show an embodiment of the weft detecting device of the present invention, in which a U-shaped arm 3 whose one end is fixed to a frame 5 of a loom extends toward the delivery side. .. A light projector 1 is arranged on the upper limb 31 of the arm 3 and a light receiver 2 is arranged on the lower limb 32 so as to face each other. Further, notches 33 are formed in various places on the arm 3 in order to avoid collision with the jet air flow for weft transport as much as possible. It should be noted that in order to form a wind surface on the front surface of the translucent device or the light receiving device or a jet stream for removing dust, the inner wall of each hole formed in the arm 3 for accommodating the light transmitting device or the light receiving device is formed. In addition, the injection port is formed in the arm 3 so as to open in the front surface of the light transmitter or the light receiver, and piping for supplying air to the injection hole is provided in the arm 3 so as not to interfere with the warp and the weft. It is preferable to form

During beating, the reed 4 having the weft guide groove 41 moves from the last retracted position indicated by A in the figure to the most advanced position indicated by C through the position indicated by B (where the beating is performed). In the figure, G indicates the movement locus region of the weft guide groove 41 during this period, but the above-mentioned throwing and receiving devices 1 and 2 are vertically separated by a distance larger than the vertical width of this movement locus region G. .. In the present embodiment, in consideration of vibration and mounting error, the light emitter and receiver are separated by a distance that is 3 to 4 times the vertical width of the movement locus area G, but the vertical width of the movement locus area G is It is even more desirable to be spaced a slightly larger distance apart.

[0010]

[Effect of the device]

 According to this invention, the weft thread is restrained in the weft thread guide groove without being brought into sliding contact with the detection device, and is reliably guided between the thrower and the light receiver. Moreover, by arranging the light emitting device and the light receiving device based on the locus of movement of the weft guiding groove of the deformed reed, the distance between the light emitting device and the light receiving device is not so large, and the level of the obtained weft detection signal is also appropriate. It is very expensive. Therefore, stable weft detection without malfunction is possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view showing an embodiment of the weft detecting device of the present invention.

FIG. 2 is a perspective view thereof.

[Explanation of symbols]

 1 Emitter 2 Light receiver 3 Arm 4 Reed 41 Weft guide groove 5 Loom frame G Weft guide groove movement locus area

Claims (1)

[Claims for utility model registration] [Claim 1] In an air jet loom equipped with a modified reed defining a weft guide groove, throwing at a distance larger than the vertical width of the movement trajectory region of the weft guide groove during beating, Photoelectric weft detection device for an air jet loom, characterized in that the light receivers are arranged opposite to each other.