JPS61239059A - Detection of weft yarn in jet loom - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a method for detecting a weft thread being flown by a jet of fluid in a weft guide passage formed on the front surface of a reed.

(Prior Art) In a jet loom in which weft threads are inserted into a warp opening using a jet of fluid, the insertion state of the weft threads has a great effect on the quality of the fabric. Therefore, in the past, in order to detect whether the tip of the weft yarn ejected from the main nozzle for weft insertion has reached a predetermined area, a weft yarn detector was installed between the woven fabric and the selvage or outside the selvage. It is common practice to install

Such a conventional device is disclosed in Japanese Unexamined Patent Publication No. 57-5947. In this conventional device, as shown in FIG. 5, a light emitting element 1 and a light receiving element 2 are installed in parallel in the direction of the weft guide path S, and a weft detector 4 has a rod-shaped lens 3 installed in front of the pixel element 1.2. The light projected from the light projecting element 1 is focused by the rod-shaped lens 3 and then reflected by hitting the weft Y, and after the reflected light is focused by the rod-shaped lens 3, the light receiving element The weft yarn Y is detected by receiving light at 2. That is, the purpose of this conventional device is to increase the change in the amount of light to increase the accuracy of weft detection.

However, when the weft detector 4 designed to improve the weft detection accuracy is installed outside the woven fabric W or the waste selvedge W1, an extra weft must be inserted in order to ensure reliable weft detection. This leads to wastage of weft threads. Moreover, even in the case of a so-called end error, which does not need to be considered as an abnormality, in which the tip of the weft yarn Y does not reach the installation position of the weft yarn detector 4 but the woven fabric is normally formed, it can be considered as a weft insertion error. Put it away. Such unnecessary operation stoppages not only cause a decrease in the operating efficiency of the loom, but also increase the proportion of weaving steps in the woven fabric when the loom is stopped and started, which adversely affects the quality of the woven fabric.

(Problem to be Solved by the Invention) Therefore, it is conceivable to attach a light emitting element or a light receiving element to the tip of a support piece that can separate the warp threads and enter the warp opening, and detect the weft threads within the warp opening. . In such a weft detection mode, it is necessary to make the thickness of the support piece as small as possible in order to smoothly enter the support piece into the warp opening, and therefore the photoelectric element attached to the support piece must be As the size becomes smaller, a decrease in performance is unavoidable.

Therefore, when weft detection is performed within the warp shedding, it is difficult to increase the change in light amount and improve the weft detection accuracy as in the conventional device.

Therefore, an object of the present invention is to provide a method that can reliably detect weft yarns even within the warp shedding.

Structure of the Invention (Means for Solving Problems) Therefore, in the present invention, a light projecting element is attached to the tip of one of a pair of support pieces formed so that the warp threads can be separated and the pieces can enter the warp opening. A light receiving element is attached to the other tip, and the pair of support pieces are spaced apart and arranged side by side in the direction of the weft guide path formed on the front surface of the reed, so that the warp can be inserted between the two support pieces, The number of pulse signals within a predetermined range including the warp detection pulse signal from the light receiving element is counted, and when this count reaches a set value, it is determined that weft has been detected, and the count does not reach the set value. In this case, the machine will be stopped.

(Function) That is, the pulse signal includes not only a plurality of detection pulse signals caused by the vibration of the weft inserted into the weft guide passage, but also a fluff detection signal or a noise signal, and the value The number of these detection signals within a predetermined range is estimated and set in advance. The predetermined range includes the time when the warp crosses between the light emitting and receiving elements during beating, and the number of detection pulse signals within the predetermined range includes the number of warp detection pulse signals 1 that occurs when the warp crosses between the light emitting and receiving elements. is included. Therefore, when the weft is inserted normally, the number of pulse signals within the predetermined range becomes a sufficient number greater than the set value, and the weft can be reliably detected.

(Example) Hereinafter, an example embodying the present invention will be described based on FIGS. 1 to 4.

A reed 12 is provided on the sleigh 11 and has a function of guiding the weft Y ejected from a main weft insertion nozzle (not shown). That is, a large number of fluid layers 1 constituting the reed 12
3. A concave guide hole 13a is formed on the front surface of the opening 13.
A guide path S for the weft Y is formed by the row a.

A mounting groove 11a is formed in the front surface of the sleigh 11 in its longitudinal direction, and a plurality of support blocks 1 are formed in correspondence with the reed 12.
4 (only one is shown in the drawing) is tightened and fixed by bolts 15 and nuts 16 fitted into the mounting groove 11a so that the sliding position can be adjusted along the mounting groove 11a. An auxiliary nozzle 17 is inserted and fixed in the vertical direction into each block 14, and an injection hole 17a at the tip of the nozzle 17 is arranged near the weft guide passage S, and the auxiliary injection fluid from the injection hole 17a is applied to the weft yarn. It is designed to assist the flight of the weft yarn Y inserted into the guide path S.

Inside the warp T group forming the woven fabric W (in this example, the woven fabric W
A weft yarn detector ■8 is fastened and fixed to the front surface of the sley 11 at a position corresponding to the material edge (near the fabric end on the opposite side of the weft insertion side) with a port 19 and a nut 20 so as to be able to adjust its sliding position along the mounting groove 112. . The weft detector 18 is connected to the support plate 2
1, a pair of support pieces 22 and 23 attached and fixed in parallel in a spaced apart manner in the direction of the weft guide path S on an attachment part 21a protruding from an example of the support plate 21, and a tip end of one of the support pieces 22. It is composed of a light emitting element 24 embedded in the support piece 23, a light receiving element 25 embedded in the tip of the other support piece 23, and a substrate 26 having a circuit for amplifying the signal from the light receiving element 25. Terminal portion 26a integrally formed with 26
A lead wire 27 connected to a light emission output circuit and a control circuit (not shown) is connected to. And both support pieces 22
23 is disposed near the bottom of the weft guide path S, and is set so that the optical axes of the light emitting/receiving elements 24 and 25 are oriented within the weft guide path S.

At the time of weft insertion, the support piece 22.
The tip of the warp 23 separates the warp threads T and enters the warp opening, and light is constantly projected from the light projecting element 24. At this time, a part of the warp threads T which have been separated by the pair of support pieces 22 and 23 are introduced between both support pieces 22 and 23. Weft Y
When normal weft insertion is performed in which the tip of the weft Y reaches the outer end position of the selvedge W1, the projected light is reflected by the same weft Y, and this reflected light is received by the light receiving element 25. At this time, the weft Y is pulled and biased within the weft guide passage S by the jetted fluid and is in a vibrating state.

Therefore, even when the tip of the weft yarn Y has reached the installation position of the weft yarn detector 18, the amount of light received by the light receiving element 25 varies and can be detected as a signal.

After inserting the weft, the sleigh 11 moves forward and performs the beating operation.
As shown by chain lines in FIG. 2, the light emitting/receiving elements 24.25 at the tips of the pair of support pieces 22.23 move from inside the warp opening to below it through the lower warp group which is transitioning to the closed state. . Therefore, the warp threads introduced between the support pieces 22 and 23 pass between the light emitting and receiving elements 24 and 25, causing a change in the amount of light received.

In addition to the above-mentioned weft detection and warp detection, changes in the amount of light in the light receiving element 25 include fluff detection, and furthermore, changes in the output signal from the light receiving element 25 include noise. Light receiving element 2
The weft detection signal, fluff detection signal, or noise outputted from 5 is amplified in an amplifier circuit, as shown in FIG. 3, and then sent to a filter circuit to remove the noise. The signal output from the filter circuit is input to the comparator circuit, and a predetermined pulse signal is output from the comparator circuit only for input signals that are higher than a set level. These pulse signals are shown in the middle graph of FIG. 4, where sy corresponds to a weft detection signal, St to a warp detection signal, and Sn to a fluff detection signal and noise. These pulse signals are input to an AND circuit, and the pulse signal is combined with a detection timing signal input from a detection timing signal generation circuit (not shown) (this is indicated by Sr in the upper graph of FIG. 4). A logical sum is taken. The detection timing signal Sr is generated when the warp detection signal St is transmitted slightly before the machine rotation angle (indicated by 01 in FIG. 4) at which the tip of the weft Y is expected to reach the installation position of the weft detector 18. It is set in a range slightly after the expected machine rotation angle position (indicated by 02 in Figure 4), and is output from the AND circuit as shown in the lower graph of Figure 4. The pulse signal always includes a pulse signal St' as a warp detection signal. The pulse signal sy', st' or Sn1 output from the AND circuit is input to the counting circuit and counted, and when this count reaches a preset integer value (hereinafter referred to as N), the counting circuit outputs a pulse signal. No machine stop signal is output and operation continues.

Conversely, when the count does not reach the value N, a machine stop signal is output, and the machine is stopped.

Note that the explanation of the block circuit in FIG.
describes the case where constant light is used,
When modulated light is used, it is necessary to interpose a detection circuit between the filter circuit and the comparator circuit of the block circuit shown in FIG.

In such a weft detection method, when the weft Y is inserted normally, it is necessary that the number of detected pulse signals within the set range of the signal Sr is equal to or greater than the set value N, and the same value N is Expected fluff detection signal and noise S
It is essential that the number is larger than the sum of the number n and the number 1 of the warp detection signal.

Therefore, the value N must be appropriately set in consideration of the occurrence of the weft detection pulse signal sy, fluff detection pulse signal, and noise Sn within the setting range of the signal Sr. settings are required. Therefore, as in this embodiment, by setting the range of the signal Sr to be relatively thick so as to include the warp detection pulse signal St regardless of the length of the weaving width of the woven fabric, the weft Y can be inserted normally. In this case, a sufficient number of detected pulse signals can be obtained.
The number of identical signals is surely greater than or equal to the set value N. For example, when the weaving width of the woven fabric is long, it takes time for the tip of the weft Y to reach the installation position of the weft yarn detector 18, so the period from the time of arrival to the time when the warp detection signal is generated is short. However, the number of detection pulse signals generated in the range of signal Sr, including the warp detection signal, is sufficient to be judged as weft detection, and is greater than the value N set by including one warp signal. growing. Therefore, weft detection is performed reliably, and unnecessary stoppage of the machine due to detection errors is avoided.

Furthermore, after the warp detection signal St is input, the circuit shown in FIG. This is convenient for setting the range.

Of course, the weft detection means of the present invention can also be applied to a case where a weft detector is installed outside the weaving width area as in the conventional case.

Effects of the Invention As detailed above, in the present invention, in order to separate the warp threads and enter the warp shedding, a thread is inserted into the tip of one of the pair of support pieces arranged in parallel and spaced apart in the direction of the weft guide path. optical element,
The wand counts the number of pulse signals within a predetermined range, including the warp detection pulse signal, from the reflective light projector/receiver device with a light receiving element installed at the other end, and when this count reaches the set value, the weft is detected. This has an excellent effect in that the weft can be detected reliably even when the weft is detected by a photoelectric element that can be attached to a thin support piece that can be inserted into the warp opening by separating the warp. play.

[Brief explanation of drawings]

1 to 4 show one embodiment embodying the present invention, and the first
The figure is a perspective view showing the weft yarn generator installed within the weaving width area, Figure 2 is a vertical cross-sectional view seen from the weft insertion direction, Figure 3 is a block circuit diagram, Figure 4 is a graph, and Figure 4 is a graph. FIG. 5 is a perspective view showing a conventional weft detection method. Weft detector 18, support pieces 22, 23, photoelectric element 24.2
5. Weft guide path S, pulse signal sy.

Claims (1)

[Claims] 1. In a jet loom in which the weft is made to fly through the weft guide passage formed on the front surface of the reed using a jet of fluid, the jet loom is arranged in parallel and spaced apart from each other in the direction of the weft guide passage so that the warp can be separated and entered into the warp opening. Counts the number of pulse signals within a predetermined range, including warp detection pulse signals, from a reflective light emitting/receiving device that has a light emitting element on one tip of a pair of supported pieces and a light receiving element on the other tip. A weft detection method in a jet loom that determines weft detection when this count reaches a set value.