JPS6231102B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a weft detection method for a fluid jet type shuttleless loom.

In a conventional weft detection method for a fluid jet type shuttleless loom, a first signal is generated immediately after the start of weft insertion;
Further, a second signal is generated immediately after the weft insertion is completed, and the weft yarn detection device is kept in operation only during a period determined by these two signals. As a result, if the presence of the weft cannot be detected by the weft detection section of the weft detection device within the period determined by the above two signals, it is determined that the weft insertion has failed, and if the presence of the weft is detected, the weft insertion is determined to have failed. It was determined that it was successful.

Therefore, in the conventional weft detection method for a fluid jet type shuttleless loom, as shown in Utility Model Application Publication No. 53-1864, an auxiliary nozzle is used to jet the jet near the selvedge, and the jet flow is detected. A detection device that detects the weft by installing a detection device in the action area and inserting the weft by dancing the weft into the detection device by the high-speed jet flow of the auxiliary nozzle does not ensure that the weft is truly inserted normally. There is no problem if the inserted weft yarn is cut while flying along the weft flight path of the reed (hereinafter simply referred to as blown-off), and the auxiliary nozzle operates only until the weft insertion is completed, so the weft breakage occurs. There is a drawback that even when the chopsticks are present in the weft detection section, it is determined that the weft thread has been inserted normally. As a result, unexpected flaws occurred in the woven fabric, leading to a decline in quality.

This invention was made in view of the drawbacks of the conventional weft detection method of a fluid jet type shuttleless loom, and provides a weft detection method that can determine that weft insertion has failed even when the above-mentioned breakage occurs. It is aimed at something.

According to this invention, even after the weft insertion is completed, the inserted weft is held (held, locked) on the main injection nozzle side.
furthermore, at least one auxiliary nozzle close to the weft detection section of the weft detection device is maintained in a spraying state, and in addition, the weft detection device is kept in an operating state for a predetermined period of time after completion of weft insertion and before reed beating. be done.
As a result, even if a weft break occurs and a weft break exists at the weft detection position, the jet from the auxiliary nozzle blows it away, resulting in a state in which there is no weft (weft insertion has failed). This allows the weft yarn detection device to detect the yarn correctly.

The present invention will be described in more detail below with reference to embodiments shown in the accompanying drawings.

As shown in FIG. 1, the weft Y supplied from the weft supply source 1 is measured by the length measuring device 2 to the length required for one weft insertion, and the measured weft Y is the weft. It is stored in the pool device 3. The stored weft yarn Y required for one weft insertion is ejected from the main weft injection nozzle 5 via the clamper 4, and weft insertion is started at a predetermined timing. At the same time as the main weft jetting nozzle 5 starts jetting, the auxiliary nozzles N ₁ to N _o sequentially jet, thereby causing the weft Y to fly along a predetermined weft flight path, and weft insertion is completed.

When this weft insertion is completed, the clamper 4 shown in FIG. 1 closes to grip the weft Y, preventing further movement of the weft Y, and completing the weft insertion. In the conventional weft yarn detection device, all auxiliary nozzles N ₁ at this point
According to the invention, at this point the at least one auxiliary nozzle _{N o located} near the weft yarn detector 6 continues to eject. By continuing the jetting from the auxiliary nozzle N _o , when a breakage occurs, the weft ends are blown away, so that the weft yarn Y no longer exists in the weft detection section where the weft detection device 6 is located. Therefore, the weft detection device 6 determines that weft insertion has failed.

FIG. 2 is a block diagram showing an embodiment of the weft yarn detection device 6 shown in FIG. It is. The light receiver 61 determines the presence or absence of incident light, and determines the presence or absence of incident light.
If Y exists, the incident light is blocked by the weft, so only a low-level voltage signal is output, and if the weft Y does not exist, it receives the incident light and outputs a high-level voltage signal. It is configured. In this way, the voltage signal output from the photodetector 61 is amplified by the amplifier 62 and then detected by the detector 63. The detected signal is amplified again by the amplifier 64 and then input to the comparator 65. Comparator 65
outputs a logical value "1" only when the level of the voltage signal output from the amplifier 64 is above a predetermined level, and based on this, the presence or absence of the weft yarn Y is first determined. That is, when the voltage signal output from the amplifier 64 is below a predetermined level and the comparator 65 is outputting a logical value of "0", the weft is located where the weft detection section consisting of the emitter and receiver 61 is located. If the voltage signal output from the amplifier 64 is above a predetermined level and the comparator 65 outputs a logical value of "1", it is determined that there is no weft where the weft detection section is located. Become.

The logical value “1” output when there is no weft is input to the first input terminal of the AND circuit 67. The second input terminal of the AND circuit 67 is connected to the output side of a differentiation circuit 66, and a timing signal TS generated each time the weft insertion is completed is input to the differentiation circuit 66.

Therefore, the AND circuit 67 operates only when the weft yarn Y does not exist in the part where the weft yarn detector is located, the comparator 65 outputs a logical value "1", and the timing is a predetermined time after the weft yarn completion. Then, the logic value "1" is output. This logical value "1" is thereafter utilized as a loom stop signal for the loom.

As is clear from the above description, according to the present invention, at least one auxiliary nozzle adjacent to the weft detection device is made to continuously eject for a predetermined period of time after the weft is completed and before reed beating, and during this predetermined period of time. Since the presence or absence of the weft yarn is detected, even if the inserted weft yarn breaks, there is no weft yarn in the area where the weft detection device is located, so it is determined that the weft insertion has failed in the same way as a normal weft insertion failure. It became possible to do so.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the weft detection method of the present invention, and FIG. 2 is a block diagram showing an embodiment of the weft detection device used in the present invention. DESCRIPTION OF SYMBOLS 1... Weft yarn feeding source, 2... Length measuring device, 3... Weft pooling device, 4... Clamper, 5... Main weft injection nozzle, 6... Weft detection device, N ₁ , N ₂ ~ _No …
...Auxiliary nozzle, 61... Light receiver, 62, 64...
Amplifier, 63...Detector, 65...Comparator, 66
... Differential circuit, 67 ... AND circuit, Y ... Weft.

Claims (1)

[Claims] 1. After the weft insertion is completed, the inserted weft is held on the side where the main weft injection nozzle 5 is located, and at least one auxiliary nozzle N _o close to the weft detection section of the weft detection device 6 is connected. A method for detecting a weft thread in a fluid injection type shuttleless loom, wherein the fluid injection type shuttleless loom is maintained in a jetting state, and the weft thread detection device is kept in an operating state for a predetermined period of time after completion of weft thread insertion.