JPS602209Y2 - Stopping prevention device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a dead stop prevention device for a loom.

Conventionally, in a loom, a feeler head consisting of a pair of electrodes is attached to a reed, and the weft inserted is detected by the feeler head when the reed is driven in, and a proximity signal synchronized with the weft insertion causes the feeler to Some machines stop when a detection signal from the head is detected and a weft insertion failure is detected.

However, with this loom, the leading end of the weft comes into contact with the feeler head when the reed is driven in, but this contact becomes unstable and the weft may separate from the feeler head, so the weft may not be inserted normally. However, when there was a proximity signal, there was often no detection signal from the feeler head and the machine would stop.

The object of the present invention is to provide a dead stop prevention device that can prevent such dead stop.

The present invention will be described below by giving examples and referring to the drawings.

FIG. 1 shows an example of a loom.

This loom is of a water injection type, and while the warp threads 1 are blown by a belt 2, when the belt 2 is opened, the weft threads 4 are injected together with water from a nozzle 3, and are inserted into the weft.The weft threads are woven with a reed 5, and a cloth 6 is woven. go.

A feeler head consisting of a pair of electrodes 7.8 is attached to a portion of the reed 5 outside the warp 1, and comes into contact with the tip side of the weft 4 when the reed 5 is driven in to detect the weft 4.

On the other hand, a proximity signal generating section (not shown) generates a proximity signal when the reed 5 approaches the cloth 6.

FIG. 2 shows an electric circuit of the above-mentioned loom, which is an embodiment of the present invention.

In the figure, H3 is a DC power supply, VR□ is a variable resistor, R1-R2
1 is a resistor, Q2 is a transistor, D1 to D are diodes, NA1 to NA□2 are NAND circuits, C□ to C
5 is a capacitor, and SW is a contact point composed of electrodes 7, 8 and the weft 4, that is, a feeler head.

FIG. 3 is a timing chart of this circuit.

When the weft yarn 4 is not in contact with the feeler head SW, the transistor Q1. When Q2 is turned off and the weft 4 comes into contact with the feeler head SW (both electrodes 7 and 8), the feeler head SW becomes conductive and the transistors Q□,
Q2 turns on.

Detection signal DO obtained from the collector of transistor Q2
υT1 is inverted by a NAND circuit NA□, and diode D2
゜D3, resistors R, ,R, and a capacitor C□ are input to an anti-tangle circuit and a NAND circuit NAG.

In the entanglement prevention circuit, unless the weft is entangled with the feeler head SW, the capacitor C□ will not be charged to a high level, and therefore the output of the NAND circuit NA2 will remain at a high level.

For this reason, the output signal of the NAND circuit NA□ is normally inverted by the NAND circuit N, inverted by the NAND circuit NA1, and input to the NAND circuit NA.

On the other hand, the proximity signal PS1 from the proximity signal generating section is supplied to the NAND circuit NA8. The output signal of the NAND circuit NA5 is input to the NAND circuit NA6 via NA9, and when there is a detection signal from the feeler head SW, the collector output DOUTI of the transistor Q2 is at a low level, and at the same time there is a proximity signal circle □. can get.

This output signal is differentiated by a differentiating circuit consisting of a capacitor C2, a resistor R8, and a diode D6, and is then differentiated by a NAND circuit NA6.
NA7, capacitor C3, diode D7, resistor R8
A first monostable circuit consisting of ~R12 is triggered at the leading edge, and from this monostable circuit a pseudo signal DDoUT8 of 50 to 60 m5 whose time width is longer than that of the proximity signal as shown in FIG.
is obtained.

Further, the output signal of the NAND circuit NA9 is differentiated by a differentiating circuit consisting of a capacitor C2, a resistor R15, and a diode D8, and then outputted to the NAND circuit NA10? A second monostable circuit consisting of NAII, capacitor, etc., diode D9, and resistors R□6 to R19 is triggered at the trailing edge, and from this monostable circuit a time width of 5
A pseudo signal PS2 of ~lQmS is obtained.

These pseudo signals.

UT29 Ps2 is input to the NAND circuit NA12, and the output signal of this NAND circuit NA□2 is a pseudo signal even though there is a pseudo signal PS2.

When UT2 is absent, the stop signal OUT is output to the stop circuit and the loom stops.

The pseudo signal DOUTI is generated if the weft hits the feeler head even once, and is not affected even if the weft leaves the feeler head during driving of the reed, thereby preventing dead stop.

The conventional circuit was configured so that the output signal of the NAND circuit NA3 and the proximity signal PS1 were input to the NAND circuit NA1□, and an idle stop occurred as shown in FIG. Since the dotted line portion is added, the idle stop is prevented as described above.

Also, if the feeler head remains in a conductive state due to entanglement of the weft yarn, the capacitor C1 will be charged to a high level, the output of the NAND circuit NA2 will become low, and the output of the NAND circuit N will remain at a high level. It's a pseudo signal.

UT□ is no longer output, a stop signal is output from the NAND circuit NAl2, and the loom is stopped.

As described above, according to the present invention, it is determined that both the detection signal from the feeler head and the proximity signal are present, and the first monostable circuit is triggered at the leading edge of the output signal, and the time from the proximity signal is determined. Generates a long output signal, triggers a second monostable circuit at the trailing edge of the proximity signal, checks the output signal of the first monostable circuit using the output signal of the second monostable circuit, and inserts the weft yarn. Since a stop signal is output when a defect is detected, it is possible to prevent the loom from stalling.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an example of a loom, FIG. 2 is a circuit diagram showing an embodiment of the present invention, and FIG. 3 is a timing chart for explaining the embodiment. NA4~NA□□・・・NAND circuit, C2~C5
...Capacitor, D6~D, ...Diode, R8~R□9...Resistance.

Claims (1)

[Scope of utility model registration request] It has a feeler head that is attached to the reed and consists of a pair of electrodes that the tip side of the inserted weft comes into contact with when the reed is inserted, and a detection signal from the feeler head is generated by a proximity signal synchronized with the insertion of the weft. In a loom that stops when a weft insertion defect is detected by inspecting the feeler head, a circuit that determines that both a detection signal from the feeler head and a proximity signal are present simultaneously and generates an output signal;
a first monostable circuit that is triggered by the leading edge of the output signal of this circuit to generate an output signal having a longer time width than the proximity signal; and a second monostable circuit that is triggered by the trailing edge of the proximity signal. and a circuit for checking the output signal of the first monostable circuit based on the output signal of the second monostable circuit and outputting a stop signal when a weft insertion failure is detected.