JPH07237821A - Remaining yarn quantity detecting device for feeder - Google Patents

Abstract

PURPOSE:To surely detect the complete consumption of a normal yarn with the required minimum consumption of the yarn when the yarn is fed by feeders used in a continuously weaving process. CONSTITUTION:The detected end of a switch substantially housed in the peripheral wall 11 of the core of a feeder is energized to be protruded in part on the yarn wound surface 12 of the core, and a lead 26 connected to the switch is extended inside of the yarn wound surface 12 and connected to a terminal 29 fixed to the lower end of the core. In this way, the volume of a yarn on the yarn wound surface of the feeder is reduced and winding pressure on the detected end is thus reduced. The switch and a detection circuit connected thereto are actuated to detect the complete consumption of a normal yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a residual yarn amount detecting device for a yarn supplying body, and more particularly to a technique for detecting a yarn of a yarn supplying body used for weaving before it is completely consumed. That is, the present invention relates to an improvement in a technique for detecting that the yarn has been consumed until the yarn supplying body reaches a predetermined remaining yarn amount.

[0002]

2. Description of the Related Art In continuous weaving using a plurality of yarn feeders, the yarns of the first yarn feeder and the yarns of the second yarn feeder are connected by knotting. Therefore, the knot of threads is inevitably woven into the fabric when the yarn feeders are replaced.

However, in a general woven fabric, even if a knot of yarns, that is, an abnormal yarn portion is woven, as a result, it does not cause a fatal weaving defect in terms of quality of the woven fabric.

However, in the case of a special woven fabric such as a glass cloth used as a base material of a printed circuit board for mounting an electronic circuit, a local protrusion in the woven portion of the abnormal thread portion causes a variation in the thickness of the insulating layer of the printed circuit board. Will have a big impact on the Therefore, in the continuous weaving of a certain kind of special fabric, it is absolutely necessary to avoid weaving the abnormal yarn portion as described above. That is, this is the reason why it is required to detect just before the change of the yarn feeder, that is, to detect that the remaining yarn of the yarn feeder reaches a predetermined amount.

As an apparatus for detecting the residual yarn amount of the yarn feeder, there is an "automatic stopping device for a shuttleless loom" disclosed in Japanese Utility Model Laid-Open No. 122322/1985. This prior application technique discloses two embodiments, one of which uses a photoelectric sensor and the other of which uses a spring sensor.

In the case of the photoelectric sensor, the light transmitter and the light receiver are arranged so as to face the yarn winding surface of the yarn feeder. It is detected that the residual yarn amount has reached a predetermined value due to a change in the light ray reflected from the yarn winding surface due to a decrease in the yarn layer of the yarn supplying body due to the consumption of the yarn.

In the case of a spring type sensor, a sensor consisting of a pair of leaf springs is inserted at the lower end of the yarn feeder between the yarn winding surface and the yarn layer of the yarn feeder. The residual thread amount reaches a predetermined value due to a change in the posture of the leaf springs caused by a decrease in the yarn layer winding pressure immediately before the change of the yarn feeder, that is, when the pair of leaf springs changes from the contact state to the separated state. Has detected that.

[0008]

By the way, in the case of using the photoelectric sensor among the above-mentioned prior arts, when the yarn layer on the yarn winding surface of the yarn feeder becomes a mesh-like pattern, The expression sensor outputs the detection signal. That is, since a detection signal is output when there is still a considerable amount of yarn remaining, for example, when using a known yarn discharging device that starts based on the detection signal and automatically discharges the abnormal yarn portion, However, not only the abnormal yarn portion but also the normal yarn portion is discharged in a considerable amount, and there is a disadvantage in that even the yarn that should be a woven fabric is wasted.

Further, in the case of using the spring type sensor, there is an advantage that the remaining yarn amount at the time of detection can be made smaller than that of the photoelectric type, but when the yarn amount on the yarn winding surface of the yarn feeder becomes small. Since the winding pressure from the thread layer that restrains the leaf spring is completely eliminated, the sensor may fall out of the yarn feeder. In addition, the leaf spring connected to the rear end of the leaf spring inserted onto the yarn feeder may be hung down due to vibration of the loom during use. In any case, when the center falls off, the pair of leaf springs are in a separated state, so that the detection signal is output at an unnecessary time. Since this easily occurs at a time considerably before the original time when the detection signal should be output, the problem of wasteful consumption of the thread occurs as in the case of the photoelectric sensor described above. Also, the sensor itself may be damaged.

Further, when the core of the yarn supplying body is rotated to wind the yarn around the core while twisting the yarn, the winding start yarn is wound around the lower end of the core over a certain width, and then the The yarn may be wound around the entire core including the points while traversing in the axial direction of the core. At this time, the portion at the beginning of winding is untwisted or is in a slightly twisted state as compared with other portions. When continuous weaving is performed using such a yarn feeder, if the yarn is glass, it is desirable that not only the knot but also the winding start portion are not woven. However, in the conventional spring-type sensor, since the sensor is inserted between the lower end of the thread winding surface and the thread layer,
The detection signal is not output unless the winding start portion at the lower end of the thread winding surface is consumed. Therefore, there is a possibility that the start time of the loom may be woven due to the delay of the loom stoppage time.

In view of the above-mentioned circumstances of the prior art, an object of the present invention is to waste most of the yarn of the yarn supplying body in use in feeding the yarn from the yarn supplying body in continuous weaving using a plurality of yarn supplying bodies. That is to surely detect that.

[0012]

For this reason, in the present invention, the biasing force of the switch, which is substantially accommodated in the core peripheral wall of the yarn feeder, is projected so as to at least partially protrude from the yarn winding surface of the core. The gist is that the lead wire connected to the switch extends inside the thread winding surface of the core and is connected to the terminal fixed to the lower end of the core.

[0013]

When the pressure from the winding thread applied to the detection end, that is, the winding pressure is reduced because the thread amount on the thread winding surface of the yarn supplying body used for weaving is reduced, the switch is connected to the switch. The detection circuit is activated to detect that the yarn has been consumed until a predetermined remaining yarn amount is reached.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows the relationship between the detecting device of the present invention and the core of the yarn feeder. A yarn layer W is formed on the core 1. In the present embodiment, the core 1 of the yarn feeder
The winding start portion W ′ is wound on the yarn winding surface near the lower end of the winding start surface, and the detection device 20 of the present invention has a winding winding surface other than the winding start portion W ′, preferably the winding start portion W ′. '
On the other hand, it is better to provide it at a predetermined position as close as possible. The degree of closeness is set based on the time delay from when the detection device 20 outputs the detection signal to when the yarn is actually discharged.

FIG. 2 shows an example of the detecting device of the present invention. At a predetermined position above the lower end of the core 1, the core 1
A radial recess 13 of the core 1 is formed in the peripheral wall 11 of the core 1 and opens in the yarn winding surface 12. A recess 15 is formed on the lower end surface of the core 1 so as to face upward. Both recesses 1
3, 15 are connected by an axial elongated hole 14.

The detection device 20 has a switch part, which is a main part thereof, provided in an upper concave portion 13, and a cylindrical spacer 21 is fixed in the concave portion 13. The spacer 21 has a plate or a dish. The spring 22 having a shape of a circle is installed. A contact 25 is fixed to the inner surface of the spring 22. Another contact 25 is fixed on the bottom wall of the concave portion 13 so as to face it. As these contacts 25, for example, contacts of the print contact type can be used. When using the print contact, one contact is printed on each of the two sheets, and each sheet is attached to the inner surface of the spring 22 and the recess 1.
The contacts may be bonded to the bottom wall of No. 3 so that the contacts face each other.

A detection end 23 is fixed to the outer surface of the spring 22, and the detection end 23 slightly projects from the yarn winding surface 12 of the core 1. The opening of the recess 13 is covered with a thin vinyl cover 24 so as to cover the detection end 23. In this way, the detection end 23 has the spring 22
Since it is fixed to the thread winding surface 12, it is elastically urged toward the thread winding surface 12. Further, since the cover 24 is provided so as to cover the detection end 23, the pressure from the winding yarn is effectively applied to the detection end 23 via the cover. That is, since a winding pressure larger than the winding pressure directly applied to the tip of the detection end 23 is applied, the sensitivity of the switch is increased accordingly. Furthermore, cotton wool or the like does not enter the recess 13.

In the above structure, the contacts 25 are separated from each other unless the detection end 23 is subjected to the winding pressure of the yarn on the yarn winding surface 12 and the spring 22 is deformed inward.

A pair of terminals 29 are fixed in the lower recess 15 via an insulator 27. These terminals 29 are connected to their respective contacts 25 by lead wires 26 extending in the elongated holes 14. Further, these terminals 29 are connected to a detection circuit as shown in FIG. 4, for example. The detection circuit is connected to the terminal 29 via the input terminal.

The detection circuit 40 shown in FIG.
1 and an amplifier 42, the detection signal from the detection device 20 is appropriately processed and supplied as a detection signal to the yarn discharging device. As a yarn discharging device, for example, JP-A-63-2
Those disclosed in 1952 can be used. That is, one jet nozzle and one suction nozzle (not shown) are arranged to face each other in front of the weft inserting nozzle (not shown), that is, so as to sandwich the weft inserting path between the weft inserting nozzle and the warp. When the detection signal is output from the detection device 20, a loom control device (not shown) stops the loom, and thereafter, this is set so that the weft yarn can be unwound from a length measurement storage device (not shown). Further, the loom controller operates the weft insertion nozzle, the jet nozzle and the suction nozzle to discharge the residual yarn and knot of the yarn feeder to the suction nozzle via the weft insertion nozzle.

Next, the operation of the detecting device 20 having the above structure will be described. When the yarn of the yarn supplying body is used as the weft, the yarn supplying body is inserted into a peg of a yarn supplying stand (not shown). A detection circuit (see FIG. 4) provided on the yarn feeding stand has an input terminal connected to the terminal 29 of the detection device 20.

When a sufficient amount of yarn is wound around the core 1, the winding pressure thereof causes the detection end 2 of the detection device 20 to be wound.
3 is pressed, the spring 22 is deformed inward by the displacement, and both contacts 25 are in contact with each other. Oscillator 4 in this state
1 outputs an "H" level signal, the detection circuit 4
Since 0 has a built-in inverter, no detection signal is output. That is, the ejector does not operate.

The amount of remaining yarn on the core 1 is reduced and the winding pressure is almost completely eliminated (for example, the number of winding yarns around the detection end 23 is 3 to 3).
(When the number of turns is 0), the spring 22 is deformed outward by the restoring force and returns to the original posture. This makes contact 2
5 are separated from each other.

As a result, the output of the oscillator 41 becomes "L" level, and the inverter 40 outputs the "H" level detection circuit 4 detection signal. That is, the ejector operates to eject at least the beginning portion W'and the knot. In this case, the normal thread portion is also discharged to some extent.

In the above example, the long hole 14 of the core 1
Although the lead wire 26 is passed through the inside, instead of this, the lead wire 26 may be extended along the peripheral wall of the central axis hole of the core 1. In this case, the elongated hole 14 becomes unnecessary. That is, as shown by the alternate long and short dash line in FIG.
And a central axis hole of the core 1 are formed so as to communicate with each other, the lead wire 26 is extended along the peripheral wall of the central axis hole of the core 1, and each end of the lead wire 26 is formed with a through hole. After that, the contact 25 and the terminal 29 are respectively connected.

Further, instead of using the switch mechanism by the contact 25 as in the above example, a known limit switch can be used. FIG. 3 shows an example of the detection device 30 having such a configuration, in which the size of the limit switch 31 used is larger than the wall thickness of the peripheral wall 11 of the core 12. In this case, a through hole 16 in the radial direction is formed in the peripheral wall 11 of the core 1, the limit switch 31 slightly protrudes into the central axis hole of the core 1, and the stay 35 causes the core 1 to move.
It is fixed to. Limit switch 31 detection end 33
Similarly to the case of the previous example, is slightly projected from the thread winding surface 12 of the core 1 and is covered with the protective cover 34.

The recess 15 may be formed so as to open in the central axial hole of the core 1 instead of the one that opens downward as in the above embodiment. That is, the recess 15 may be formed in the radial direction of the core 1, the terminal 29 may be fixed so as to extend in the radial direction, and may be connected to the input terminal of the detection circuit 40 in the central axis hole. Further, in the above embodiment,
Although the concave portion 13 is provided at a position excluding the winding start portion, it is not always necessary to do so and may be provided at a position corresponding to the winding start portion.

[0028]

As is apparent from the above, according to the present invention, since the residual yarn amount is detected by the winding pressure, the residual yarn amount at the time of detection can be made smaller than in the case of the photoelectric sensor. Moreover, since the detection device is substantially embedded and fixed in the peripheral wall of the core, it does not fall off the core due to vibration or reduction of winding pressure. As a result, it is possible to stably and reliably detect the point that the yarn of the yarn feeder being used is almost consumed. Further, since not only the switch but also the terminal are fixed to the core, the detection device is not damaged even if the core is rotated when winding the yarn.

[Brief description of drawings]

FIG. 1 is a perspective view showing an arrangement mode of a detection device of the present invention.

FIG. 2 is a partial cross-sectional side view showing the embodiment.

FIG. 3 is a partial cross-sectional side view showing a main part of another embodiment.

FIG. 4 is a circuit diagram showing a configuration of a detection circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 core 12 thread winding surface 13,15 recess 20 detection device 22 spring 23 detection end 25 contact point 26 lead wire 29 terminal 30 detection device 31 limit switch 33 detection end 35 stay 40 detection circuit 41 oscillator

Claims (2)

[Claims] 1. A lead wire connected to a switch, wherein a detection end of a switch substantially accommodated in a core peripheral wall of a yarn feeder is biased so as to project at least partially onto a yarn winding surface of the core. Is connected to a terminal fixed to the lower end of the core and extending inside the yarn winding surface of the core. 2. The detection device according to claim 1, wherein the detection end is covered with a cover.