JPS60259655A - Weft yarn detector - 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 Field of the Invention The present invention relates to a weft detection device using an energized tweeter in a loom.

2. Description of the Related Art Conventionally, in a loom, for example, as shown in FIG.
is opened and closed by a belt frame (not shown), and when the belt frame is opened, the weft yarn 3 is injected together with water from the nozzle 2 and inserted into the opening of the warp yarn 1, and the weft yarn 3 is driven into the fabric 5 side by the reed 4 to form the fabric. 5 is being woven. The reed 4 is normally at the home position shown in the figure, and each time the weft yarn 3 is inserted into the opening of the warp yarn 1 from the nozzle 2, it moves forward and returns to the home position after driving the weft yarn 3 into the fabric 5 side. The energized tweeter 6 has a pair of electrodes 61 and 62, and is fixed integrally to the reed 4, and when the reed 4 moves forward, the weft 3 is connected depending on whether the electrodes 61 and 62 are connected by the weft 3 or not. Detect presence. As shown in FIG.
A high voltage is applied to the electrodes 61 and 62 to detect the weft yarn 3 and apply the output signal to the amplifier 8. In other words, electrode 6
1.62 are connected by the weft 3, so that the current 1 or the amplifier 8 is passed through the weft 3 between the high voltage section 7 and the electrodes 61 and 62.
The output signal of the amplifier 8 becomes a weft state. A stop circuit (not shown) stops the operation of the loom if the weft 3 is not woven and the output signal of the amplifier 8 does not become a weft presence state at the timing when the energized tweeter 6 should detect the weft 3. Here, the high voltage part 7 uses a part with a small current capacity because there is a risk of electric shock if one with a large current capacity is used.

Problems to be solved by the invention The above-mentioned energized feeler 6. In the weft yarn detection device comprising a high voltage section 7 and an amplifier 8, as the loom continues to operate, dust, glue, etc. accumulate on the energized tweeter 6, and the ground insulation resistance 9 decreases. Therefore, the voltage applied to the energized tweeter 6 drops and the current 1 decreases, and the gain of the amplifier 8 remains constant, so even if the energized feeler 6 detects the weft 3, the output signal of the amplifier 8 is A pneumatic phenomenon occurs in which the weft is not present and the loom stops operating.

Means for Solving the Problems The present invention provides an energized tweeter with a control section that detects the voltage applied by the high voltage section and controls the gain of the amplifier in accordance with this voltage.

Operation: A high voltage is applied to the energized tweeter from the high voltage section.7. :
The weft is sensed by the machine, and its output signal is amplified by an amplifier.

The control section detects the voltage applied to the energized tweeter, controls the gain of the amplifier according to this voltage, and decreases the gain of the amplifier when the voltage decreases.

Embodiment FIG. 1 shows an embodiment of the present invention. In this embodiment, a control section 10 consisting of a voltage detection circuit is provided in the above-described weft detection device for a loom. This voltage detection circuit 10
detects the voltage applied to the electrode 61 of the energized tweeter 6, and applies the detection signal to the amplifier 8 to control its gain. Therefore, the amplifier 80 gain changes depending on the voltage on electrode 61, and increases as the voltage on electrode 61 decreases. Therefore, even if the voltage of the electrode 61 decreases and the output signal of the energized tweeter 6 becomes smaller (even if the current becomes smaller), the gain of the amplifier 8 increases, so when the energized tweeter 6 detects the weft thread 3. The output signal of the amplifier 8 becomes a weft presence state, and the loom does not become air pressured.

Effects of the Invention As described above, the present invention detects the voltage applied to the energized tweeter and controls the gain of the amplifier according to this voltage. Even if the voltage applied to the energized tweeter decreases, the output signal of the amplifier will remain in the weft presence state when the energized tweeter detects the weft, and the loom will no longer be under pressure.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram showing a conventional weft detection device, and Fig. 3 is a block diagram showing an embodiment of the present invention.
- It is a top view showing an example. G: Energized tweeter, 7: High voltage section, 8:
...Amplifier, 10...Control unit.

Claims (1)

[Claims] In a loom, an energized tweeter is provided integrally with a reed and detects a weft when the reed moves forward, a high voltage section applies a high voltage to the energized tweeter, and an amplifier amplifies an output signal of the energized tweeter. A weft detection device comprising: a control section that detects a voltage applied to the energized tweeter and controls a gain of the amplifier according to this voltage.