JPH0565609B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a weaving prevention circuit for preventing blind weaving (weaving a cloth using only warp threads without weft insertion) in a loom.

PRIOR ART Hitherto, this type of blind weave prevention circuit has not been known.

Problems to be Solved by the Invention Figures 2 and 3 show an example of a waterjet type loom. In this waterjet type loom, the warp threads 1 are opened and closed by a heald frame (not shown), and when the heald frame is opened, the weft threads 3 are injected together with water from the nozzle 2 and inserted into the opening of the warp threads 1.
The weft 3 is driven into the cloth 5 by the reed 4, and the cloth 5 is woven. The reed 4 is normally at the home position shown in Fig. 2, and each time the weft 3 is inserted into the opening of the warp 1 from the nozzle 2, it advances to the position shown in Fig. 3 and returns to the home position after driving the weft 3. Return to position. The tip of the weft yarn 3 ejected from the nozzle 2 reaches the catch cord 6, is driven in by the reed 4, and is captured by the catch cord 6 as the catch cord 6 is twisted by the spindle 7.
The cutter guide 8 and feeler head 9 are attached to the reed 4.
When the reed 4 moves forward, one end of the weft 3 is cut by a cutter 10. The cloth 5 and the catch cord 6 are wound up in the direction of the arrow as the cloth is woven, and the cutter 11 cuts the other end of the weft yarn 3. There are always three to five weft yarns (residual yarns) 12 that have not been cut by the cutter 11, and the feeler head 9 detects the weft yarns 3 when the reed 4 moves forward. The filler head 9 has a pair of electrodes 9 ₁ and 9 ₂ , and the presence or absence of the weft thread 3 is detected depending on whether or not the weft thread 3 is connected between the electrodes 9 ₁ and 9 ₂ . The weft detection signal from the feeler head 9 is amplified by an amplifier 13 as shown in FIG. 4, and is output to a stop circuit 14. The proximity switch is driven by a drive unit integrated with the movable system of the loom in synchronization with the advancement of the reed 4, and generates a position signal when the weft 3 is driven into the reed 4. When the position signal from the proximity switch is input, the stop circuit 14 operates the brake 15 to stop the movable system of the loom if the output signal of the amplifier 13 indicates no weft, thereby stopping the operation of the loom. stop weaving.
Further, when the stop circuit 14 enters the stop mode or receives a stop signal by pressing an off button, etc., the stop circuit 14 operates the brake 15 in accordance with the position signal.

However, in this loom, if the output signal of the filler head 9 remains in the weft presence state due to a failure of the filler head 9, the output signal of the amplifier 13 will remain in the weft presence state even if the weft thread 3 is not inserted for some reason. The loom does not stop running,
Blind weaving is performed.

Means for Solving the Problems The present invention provides a loom that stops when the weft is not inserted due to the weft detection signal from the filler head, and the weft detection signal continuously indicates that the weft is present for a predetermined period of time or more. The device is equipped with a timer that detects the occurrence of the problem and outputs a stop signal.

Operation If the filler head and the weft insertion are normal, the input signal of the timer means will be in the weft state continuously for a certain period of time T ₁ at a constant cycle, and the input signal of the timer means will be in the weft state continuously. The stop signal is not output when the time T ₁ when the state reaches the state is measured and this time T ₁ does not reach the predetermined time T ₂ . However, if the input signal of the measuring means is continuously in the weft presence state for a predetermined time T2 _or more due to a failure of the filler head, a stop signal is output from the timing means and the operation of the loom is stopped.

Embodiment As shown in FIG. 1, an embodiment of the present invention is such that a weave prevention circuit 16 is provided in the waterjet type loom described above, and the output signal of the amplifier 13 is continuously maintained in a weft state for a predetermined period of time or longer. When the weaving occurs, a stop signal is output to the stop circuit 14, and the brake 15 is activated to stop the operation of the loom.

The anti-blind circuit 16 is composed of a timing means consisting of a diode D, a capacitor C, a resistor R, a Zener diode ZD, and a transistor Q as shown in FIG. The output signal of the amplifier 13 is at a high level only when there is a weft, and is applied to the cathode of the diode D. Therefore amplifier 1
If the output signal of No. 3 is not in the weft presence state and becomes a low level, the electric charge stored in the capacitor C is discharged through the diode D, resulting in a reset state. When the output signal of the amplifier 13 becomes a weft presence state (high level), the diode D is turned off and the capacitor C is charged from the DC power supply through the resistor R. The charging voltage of the capacitor C is applied to the base of the transistor Q via the Zener diode ZD, and is compared with a reference voltage consisting of the sum of the Zener voltage of the Zener diode ZD and the base-emitter voltage of the transistor Q. When the charging voltage of capacitor C reaches the reference voltage, transistor Q
is turned on, a low-level stop signal is output to the stop circuit 14, the brake 15 is activated, and the operation of the loom is stopped. If the filler head 9 and the weft insertion of the weft thread 3 are normal during operation of the loom, the output signal of the amplifier 13 will be in the weft state continuously for a certain period of time T ₁ at a certain period, and if this time T ₁ is short Therefore, the charging voltage of capacitor C does not reach the reference voltage, and no stop signal is output. However, if the output signal of the amplifier 13 remains in the weft state continuously for a certain period of time T ₂ (T ₂ > T ₁ ) due to a failure in the feeler head 9, the charging voltage of the capacitor C reaches the reference voltage and the transistor Q It turns on, a stop signal is output, and the operation of the loom is stopped.

Effects of the Invention As described above, according to the present invention, in a loom that stops when the weft is not inserted due to the weft detection signal from the filler head, the weft detection signal indicates that the weft is present continuously for a predetermined period of time or more. When the weaving occurs, a stop signal is output to stop the operation of the loom, so it is possible to prevent blind weaving due to failure of the filler head.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a circuit section of an example of a loom to which the present invention is applied, Figs. 2 and 3 are plan views showing different states of an example of the loom, and Fig. 4 is a circuit diagram of the same loom. The block diagram in FIG. 5 is a circuit diagram showing one embodiment of the present invention. 16...Timekeeping means.

Claims (1)

[Claims] 1. In a loom that stops when the weft is not inserted due to a weft detection signal from a feeler head that is provided integrally with the reed and detects the weft when the reed moves forward, the weft detection signal continuously detects the weft for a predetermined period of time or more. What is claimed is: 1. A blind weaving prevention circuit characterized in that the circuit is equipped with a timing means for detecting that the present condition has been reached and outputting a stop signal to stop the loom.