JPH0519343Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field of the Invention The present invention relates to a weft inserting device for a fluid injection type loom, and in particular, in the process of supplying weft yarn from a plurality of yarn supplying bodies in a knotted state, the knot of the weft yarn is electrically tied. It concerns the device for detection.

Prior Art If the winding end ends and winding start ends of a plurality of yarn supply bodies are supplied to a weft insertion device in a knotted state, weft insertion can be performed continuously for the plurality of yarn supply bodies. During this feeding, a state in which the weft yarn is switched from the yarn supplying body being pulled out to the next yarn supplying body,
In other words, the state of changing the ball is, for example,
As described in FIGS. 1 and 2 of the publication No. 50895, detection can be performed using an optical sensor, a mechanical switch, or the like.

However, with the above-mentioned detection means, the ball change state is detected only at the knotted part and only by the movement of the thread, so it is prone to malfunction when exposed to light or vibration from the outside. This causes the loom to stop unnecessarily, lowering the operating rate, which is the biggest drawback in practice.

OBJECTIVE OF THE INVENTION The objective of the invention is therefore to improve the shortcomings, namely the reliability of operation, of conventional detection means in detecting knots in weft threads.

Therefore, the present invention detects the weft knot as a change in tension between a plurality of yarn supplying bodies and a length measuring storage device, and detects the knot of the weft yarn as a change in tension from this tension signal by detecting a change in the magnitude relationship of the signal level. Along with generating a knot signal,
By detecting the ball change state in advance and applying an AND condition between the ball change signal and the knot signal, malfunctions are prevented.

Structure of the invention First, FIG. 1 shows the following in relation to the weft insertion device 1
The structure of the thread knot detection device 2 of this invention is shown.

First, the weft insertion device 1 includes a length measuring storage device 5 and a main nozzle 6 in order to pull out a plurality of weft yarns 3 from, for example, two yarn supply bodies 4 and perform weft insertion to a certain length. Weft yarn 3 of two yarn feeders 4
is connected by a knot 31 at the winding end end and winding start end, is pulled out from one yarn feeder 4, and is connected to a tensor 7 and a fixed yarn guide 8.
and the movable body 9, and finally the length measurement storage device 5.
The rotating yarn guide 10 has been reached. Note that the movable body 9 includes a yarn guide 8 and a rotating yarn guide 10.
The tension of the weft thread 3 is detected as a displacement in a direction intersecting the longitudinal direction.

The rotating yarn guide 10 is located on the axis of the length measurement storage drum 11, and rotates with respect to the fixed drum 11.
The weft yarn 3 is wound around the outer peripheral surface of the weft yarn 3 while being locked by the locking pin 12, and stored while measuring the length.
When this locking pin 12 is inserted horizontally, the operation part 13
When the weft yarn 3 is driven by the drum and retreats from the outer circumferential surface of the drum 11, the weft yarn 3 is unwound on the outer circumferential surface of the drum 11, and after being guided by the yarn guide 14, the weft yarn 3 is unwound by the main nozzle 6 during warp opening. It is put aside.

Next, the thread knot detection device 2 of the present invention includes a detection section 15 and a comparison section 16.

The detection unit 15 is a conversion element such as a piezoelectric element, a displacement detection element, or a strain gauge that converts the tension of the weft thread 3 into an electrical tension signal, and the output signal is transmitted through the amplification circuit 17 and differentiation circuit 18 of the comparison unit 16 on the output side. ,
It is connected to one input terminal of the comparison circuit 19.
The other input end of this comparison circuit 19 is connected to a reference setter 20. Further, the output terminal of this comparison circuit 19 is connected to one input terminal of an AND circuit 21.

Further, this comparison section 16 includes a bead changing sensor 22 near the thread knotting part in order to detect the bead changing state. This ball change sensor 22
is connected to the other input terminal of the AND circuit 21 via an amplifier circuit 23 and a signal conversion circuit 24. The output terminal of this AND circuit 21 serves as the output terminal of the comparator 16.

Function of the device As already described, the weft insertion device 1 pulls out the weft yarn 3 from one yarn supplying body 4, stores it in the length measurement storage device 5 while measuring the length, and attaches it to the locking pin 12 at the time of weft insertion. The material is then unwound and placed in the material through the main nozzle 6.

During the weft insertion process, the detection unit 15 detects the tension of the running weft thread 3, and generates an electrical tension signal proportional to the tension, as shown in FIG. This tension signal is amplified by an amplifier circuit 17, and as shown in FIG. Since the reference value signal set in advance from the reference setting device 20 is input to the other input terminal of the comparison circuit 19,
The comparison circuit 19 compares the magnitude relationship between them and changes the output. Knot 31 in running weft thread 3
does not exist, the tension signal of the detection unit 15 is
As shown in FIG. 2, the level fluctuates in a range lower than the level of the reference value signal. However, when the knot 31 of the weft thread 3 passes through the movable body 9, the movable body 9 changes instantaneously, so the detection unit 15 temporarily generates a high-level tension signal. When the tension signal becomes higher than the reference value, the comparison circuit 19
generates an “H” level knot signal and sends it to one input terminal of the AND circuit 21.

By the way, before the knot 31 passes through the detection unit 15, the bead change sensor 22 detects the bead change state, generates a bead change signal, and sends this to the amplifier circuit 23. At this time, the signal conversion circuit 24 generates a condition signal for changing the ball over a predetermined time width. As a result, the AND circuit 21
inputs the "H" level knot signal and the "H" level switching condition signal, checks the AND condition, and passes the knot signal. In this way, the knots 31 between the plurality of yarn supplying bodies 4 are detected as a tension signal by the detection section 15, and then extracted as a knot signal by the comparison section 16 when there is a large level change.

And this knot signal is
As a signal for automatically controlling the pressure pattern of pressure fluid for weft insertion according to the state of weaving changes, or as a signal for automatically controlling the pressure pattern of the pressure fluid for weft insertion, as in Japanese Patent Publication No. 1989-50895, weaving of knots. It is used as a signal to automatically move a new yarn supplying body to a predetermined position and exchange multiple yarn supplying bodies automatically, as in JP-A No. 48-67546. Ru.

Modified example of the invention In the above embodiment, a differentiation circuit 18 is incorporated inside the comparison section 16 in order to emphasize changes in the tension signal, but this differentiation circuit 18 is not necessarily required and is therefore omitted. You may.

Effects of the invention: Since an AND condition is adopted between the weave change state and the large change part in the tension signal, there are no malfunctions due to changes in the physical properties of the weft thread, and thread knots can be reliably detected.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the thread knot detection device of the present invention, and FIG. 2 is a waveform diagram during operation. 1... Weft insertion device, 2... Yarn knot detection device, 3... Weft, 4... Yarn feeder, 5... Length measurement storage device, 6... Main nozzle, 15... Detection section,
16... Comparison section, 18... Differential circuit, 19... Comparison circuit, 21... AND circuit, 22... Ball change sensor, 24... Signal conversion circuit, 31... Knot.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) Weft yarn is pulled out from a plurality of yarn feeders in a knotted state, stored while measuring the length using a length measurement and storage device, and the stored weft yarn is unwound at the time of weft insertion. In the weft insertion device that inserts the weft using the main nozzle, there is a detection section that detects a knot as a change in tension when the weft passes between the yarn supplying body and the length measurement storage device, and a tension signal from this detection section and a reference. and a comparator section that compares the value signals and generates a knot signal based on the change in their magnitude relationship.In the comparison section, there is a weave change sensor that detects the weave change state of a plurality of yarn supplying bodies, and this weave change sensor. A thread characterized by incorporating a signal conversion circuit that converts a signal from a sensor into a condition signal of a predetermined time width, and an AND circuit that takes an AND condition between the condition signal of this signal conversion circuit and the knot signal. Knot detection device. (2) The yarn knot detection device according to claim 1, which is characterized in that a differential circuit is incorporated in the transmission path of the tension signal in the comparing section.