JPH0533246A - Weft-detection apparatus for loom - Google Patents

Abstract

PURPOSE:To prevent the detection miss of weft sensor by judging to be abnormal by a weft detection apparatus and stop the loom when a yarn-exist signal is present in the generation of an abnormality defection timing signal after the end of the weft-detection timing signal. CONSTITUTION:A yarn-exist signal is outputted by the presence of a weft passing in contact with a pair of detectors. When the yarn-exist signal is present in a period specified by a weft-detection timing signal, the weft-insertion is judged to be normal by a weft-insertion detecting circuit of a weft-detector. If the cycle of the above yarn-exist signal becomes a prescribed generation frequency over plural cycles in the generation of the abnormality detection timing signal between the end of the above weft-detection timing signal and the start of the next weft insertion, the system is judged to be abnormal by the above weft detection apparatus to output a signal to stop the operation of the loom.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weft detecting device for detecting that a weft has been properly inserted into the opening of a warp,
In particular, the present invention relates to a weft detection device provided with means for detecting an abnormality in the device.

[0002]

2. Description of the Related Art Generally, a weft detecting device generates a yarn presence signal indicating that a weft yarn is present, for example, a sensor such as an electrode type feeler, and the yarn presence signal is specified by a weft detection timing signal. And a weft-insertion detection circuit that outputs a weft-insertion completion signal which means that the weft insertion has been normally performed when the weft insertion is present within the predetermined period. In such a weft yarn detecting device, when a pair of electrodes such as an electrode type feeler has a poor insulation due to a leakage of electric current or entanglement of cotton wool, a yarn present signal is always output. Sometimes it was not possible to judge the success or failure of the insertion. This occurs not only in the electrode type feeler but also in other types, for example, in the photoelectric type feeler, because the cotton wool is deposited on the feeler head.

Conventionally, in order to detect such an abnormality of the weft detecting device, an abnormality detection timing signal is generated at the time when the weft is not originally present, and when the sensor outputs the yarn presence signal at this time, A device provided with an abnormality detection circuit for determining that the weft detection device is abnormal and outputting an abnormal signal has been proposed (Japanese Patent Publication No. 51-16488, Japanese Patent Publication No. 54-24502, and Japanese Patent Publication No. 56-48619).
Issue). However, in all of these devices, the time for judging the abnormality / normality of the sensor is simply set at the time when the weft does not originally exist. Therefore, after detecting the abnormality, the loom is stopped. In such a case, the sensor was in a so-called missed state in the weft insertion cycle immediately before it was determined to be abnormal, and it was unclear whether weft insertion was normally performed. Therefore, it is indispensable to visually confirm the success or failure of the weft insertion after the loom is stopped, and if the weft insertion is not normally performed, it is necessary to restore the weft insertion. As described above, there is a problem that complicated work is inevitable when the loom is stopped after the abnormality is detected.

Further, for example, Japanese Patent Publication No. 49-8833, Japanese Patent Laid-Open No. 61-179346, and Japanese Utility Model Laid-Open No. 61-7.
Like the sensor disclosed in Japanese Patent No. 3685 or Japanese Patent Publication No. 59-42094, a weft thread is passed between a pair of detection bodies while being in contact with both detection bodies, and a signal generated by this contact passage is generated. In the case of a sensor that outputs the change as a yarn presence signal, a unique phenomenon that the weft is clogged between the two detectors may occur when the sensor passes through the contact. That is, the weft thread passes between the two detection bodies while being pushed by the reed, but if the weft thread is loose, the weft thread cannot pass through between the two detection bodies and is clogged between the two detection bodies. Weft insertion was sometimes completed while the weft thread was still connected to the catch cord on the further downstream side from the weaving edge of the woven fabric through both the detection bodies on the downstream side in the weft insertion direction. Even in this case, the sensor always outputs the yarn presence signal, and it may not be possible to determine the success or failure of the weft insertion thereafter. Such a thread clogging phenomenon is mostly solved by the next weft insertion, because the jammed weft is pushed by the weft inserted next time.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate a so-called overlooked state of a sensor by detecting an abnormality of a weft detecting device as soon as possible and stopping a loom.

[0006]

SOLUTION, ACTION, EFFECT The present invention provides weft insertion detecting means for determining that weft insertion is normal when a yarn presence signal indicating the presence of a weft yarn is present at a time specified by a timing signal for weft detection. An abnormality detection timing signal generating means for generating an abnormality detection timing signal from the end of the weft yarn detection timing signal to the start of the next weft insertion; and the yarn presence signal when the abnormality detection timing signal is generated. Is present, an abnormality detecting means for determining that the weft detecting device is abnormal and outputting a loom stop signal is included.

When the weft insertion is normally performed, the yarn presence signal exists at the time when the weft detection timing signal is generated, but disappears at the end of the weft detection timing signal. Therefore, the weft insertion detecting means detects the presence of the yarn presence signal at the time specified by the weft detection timing signal and outputs a weft insertion completion signal.
Further, when an abnormality occurs in the weft detecting device, the yarn presence signal is present at a time other than the time when the weft detecting timing signal is generated. Therefore, the abnormality detection means detects the presence of the yarn presence signal when the abnormality detection timing signal is generated, determines that the weft detection device is abnormal, and outputs a signal for stopping the loom. At this time, the abnormality detection timing signal is generated at any time from the end of the timing signal for weft detection to the start of the next weft insertion. Therefore, the abnormality of the weft detection device before the next weft insertion starts. And the loom stop signal can be output.

As described above, according to the present invention, the generation timing of the abnormality detection timing signal is set to an arbitrary timing between the end of the weft detection timing signal and the start of the next weft insertion. Therefore, it is possible to determine the abnormality of the weft detecting device by the latest at the latest at the time of starting the weft insertion, and output the loom stop signal. As a result, weft insertion after the abnormality detection can be prevented. Therefore, it is no longer necessary to confirm the success or failure of the weft insertion after stopping the loom and the repair operation when the weft insertion is not normally performed, which are conventionally required.

The abnormality detecting means determines that the weft detecting device is abnormal when the cycle in which the yarn presence signal exists at the time of generation of the abnormality detection timing signal reaches a predetermined occurrence frequency over a plurality of cycles, and determines that the weft detecting device is abnormal. A stop signal can be output. The predetermined frequency includes a state in which a predetermined number of cycles have occurred a predetermined number of times, a state in which a plurality of predetermined cycles have occurred consecutively, and the like. According to this configuration, the abnormality detection means excludes the yarn presence signal due to cotton or the like that has temporarily come in, and outputs the loom stop signal by determining the abnormality only when the weft detection device is originally abnormal. can do.

The abnormality detection timing signal generating means is
It can be configured as a means itself for generating a timing signal for weft detection, which is conventionally provided. That is, the weft detection timing signal used conventionally is used as the abnormality detection timing signal, and the abnormality detection means checks the presence or absence of the yarn presence signal at the end of the weft detection timing signal, and the presence of the yarn presence signal is detected. While the weaving device is running, it is possible to determine that the weft detecting device is abnormal and output the loom stop signal. This is based on the fact that the weft detection timing signal is generally set with a margin in time including the time when the weft should exist, so that the yarn presence signal does not exist at the end of the weft detection timing signal. . According to this configuration, since the generation means dedicated to the abnormality detection timing signal can be omitted, the weft detection device can be simplified. Further, since the abnormality detection timing signal is interlocked with the weft detection timing signal, it is sufficient to change only the weft detection timing signal when the timing setting needs to be changed, and therefore the timing setting change operation is facilitated. Become.

The abnormality detection timing signal generating means is
It can be composed of a unit for generating a weft yarn detection timing signal and a unit for converting the weft yarn detection timing signal into a signal delayed by a predetermined period. That is, the weft yarn detection timing signal used conventionally is delayed by a predetermined period and used as an abnormality detection timing signal, and the abnormality detection means confirms the presence or absence of the yarn presence signal when the delay signal is generated. When the yarn presence signal is present, it is possible to determine that the weft yarn detection device is abnormal and output the loom stop signal.
As described above, when the weft yarn detection timing signal itself is used, depending on the fabric, the yarn presence signal may exist even at the end of the weft yarn detection timing signal. In this case, it is necessary to surely generate the abnormality detection timing signal at the time when the thread presence signal is not originally present. However, by adjusting the delay time of the delay signal, this need can be facilitated. Can be realized.
According to this configuration, since the abnormality detection timing signal is linked to the weft detection timing signal, even if it is necessary to change the setting of the generation timing of the weft detection timing signal, the abnormality detection timing is adjusted accordingly. Since it is not necessary to change the setting of the signal generation timing again, the setting change operation becomes easy.

The weft-insertion detecting means allows the weft thread to pass through the pair of detection bodies while allowing the weft thread to come into contact with the pair of detection bodies, and generates the yarn presence signal when the weft thread comes into contact with the detection body. A weft-insertion detection circuit that determines that weft insertion is normal when the yarn-existence signal is present at the time specified by the weft-detection timing signal, and the yarn-existence occurs when the abnormality detection timing signal is generated. It is also possible to determine that the weft yarn detecting device is abnormal and output the loom stop signal only when a plurality of cycles in which the signal is present continue. According to this configuration, it is possible to stop the loom only when the weft detecting device is abnormal, while distinguishing the yarn clogging phenomenon peculiar to the weft insertion detecting means of the above type and the abnormality of the weft detecting device.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a weft detection device 10 includes a feeler head 12 which senses the weft and outputs an electrical signal corresponding to the presence or absence of the weft.

As shown in FIG. 2, feeler head 12
Is above the first detector 16 and the base 14 made of conductive material attached to the frame of the loom, the first and second detectors 16 and 18 made of conductive material attached to the base 14. And a guide 20 made of a non-conductive material attached to the base 14.

The first detector 16 has a non-conductive seat portion 22.
It is attached to the base portion 14 via. The second detector 18 is a contact piece made of an elastic material, and is usually the first piece.
Is pressed to the side of the detection body 16 and is electrically connected to the base portion 14. The two detectors 16 and 18 are electrically short-circuited to each other by contact, and the weft yarn 2 inserted
It is arranged so as to form a contact of an electric switch which is electrically opened by 4.

When the weft yarn 24 put into the weft is struck by the reed 26 before weaving, the two weft detectors 16 and 18 are inserted.
While passing through the front end portions of the detection bodies 16, that is, while electrically opening the both detection bodies 16 and 18, they pass between the front end portions of the detection bodies 16 and 18. Both detectors 16 and 18 are connected to the amplifier circuit 32 shown in FIG. 1 via separate lead wires 28.

As the feeler head 12, other than the structure shown in the drawings, for example, JP-B-49-8833, JP-A-61-179346 and JP-A-61-7.
Other structures such as those described in Japanese Patent No. 3685, Japanese Utility Model Laid-Open No. 63-110593, etc. may be used.

Referring again to FIG. 1, one sensing element of the feeler head 12 is connected to the positive terminal (+) of the DC power source through the resistor 30 and the amplifying circuit 3
2 is connected to one of the input terminals. On the other hand, the other detector of the feeler head 12 is connected to the negative terminal of the DC power supply (ground in the illustrated example) and to the other input terminal of the amplifier circuit 32.
Therefore, the output signal of the feeler head 12 is at a high level when both detectors are open and at a low level when both detectors are short-circuited.

A comparison circuit 34 is provided on the output side of the amplification circuit 32.
And the noise filter 36 is arranged in that order. The amplifier circuit 32 is a known circuit including an operational amplifier 38 and a plurality of resistors 40 and 42. Comparison circuit 3
6 is a known circuit including a comparator 44 and a plurality of resistors 46 and 48. The noise filter 36 consists of a known circuit with a resistor 50, an inverter 52 and a capacitor 54.

In the illustrated example, the feeler head 12, the amplification circuit 32, the comparison circuit 36, and the noise filter 3 are shown.
Reference numeral 6 constitutes a sensor that generates a yarn presence signal when the weft yarn passes while being in contact with the detection body of the feeler head 12. Output signal of sensor, ie noise filter 3
The output signal a of 6 is a high level thread presence signal when both detection bodies are open, and a low level thread absence signal when both detection bodies are short-circuited.

The output signal a of the sensor is the weft insertion detection circuit 5
6 is supplied. The weft insertion detection circuit 56 outputs an AND signal c of the output signal a of the sensor and the weft detection timing signal b supplied to the terminal 58.
Equipped with.

The weft yarn detecting device 10 further uses the output signal a of the sensor and the weft yarn detecting timing signal b supplied to the terminal 58 to detect the presence of the yarn presence signal when the abnormality detecting timing signal is generated. Includes an abnormality detection circuit 62 that outputs an abnormality signal indicating that the device is abnormal.

The abnormality detection circuit 62 includes an inverter 64 for inverting the weft detection timing signal b, and a resistor 66 connected in series between the positive side terminal (+) and the negative side terminal (ground) of the power source. And a capacitor 68, a 2-input AND gate 70, and two D-type flip-flops 72 and 74.

One input terminal of the AND gate 70 is connected to the connection between the resistor 66 and the capacitor 68, and thus this input terminal is always maintained at a high level while the power is turned on. On the other hand, the output signal a of the sensor is supplied to the other input terminal of the AND gate 70.

The data input terminal D of the flip-flop 72 is connected to the positive terminal (+) of the DC power supply.
The flip-flop 72 is reset when the output signal of the AND gate 70 is at a low level, and when the output signal d of the inverter 64 rises, the output signal d of the inverter 64 is taken in to take in a data input (to detect an abnormality).
To the clock terminal C. The rising edge of the signal d coincides with the end of the timing signal for weft detection b.

The data input terminal D of the flip-flop 74 is connected to the output terminal Q of the flip-flop 72. The flip-flop 74 is initially reset by the input signal to the other input terminal of the AND gate 70 when the power source rises, and the inverter 64
The output signal d of the inverter 64 is received at the clock terminal C in order to take in the data input (to detect an abnormality) at the rise of the output signal d.

In the weft yarn detecting device 10, when the power is turned on, the power supply voltage rises as shown in (1) of FIG. 3, the noise filter 36 outputs the signal a shown in (2) of FIG. It is assumed that the weft yarn detection timing signal b shown in (3) is input to the terminal 58.

In the signal a, the pulse a1 is a yarn presence signal and is not generated when the weft yarn is not present. The pulse a2 is a signal when the thread is temporarily jammed,
It will disappear with the next weft insertion. Therefore, the pulse a
2 is a signal having a time width of one cycle T or less of the weft yarn detection timing signal b. However, the pulse a3 is a signal when the device fails due to dust or the like, and is therefore a signal having a time width exceeding one cycle T of the weft detection timing signal b.

The weft insertion detecting circuit 56 outputs a signal c shown in (4) of FIG. 3 which is a logical product signal of the signal a and the signal b. In the signal c, the pulse c1 is the weft insertion completion signal, and this weft insertion completion signal is not generated when the thread present signal is not present.

On the other hand, in the abnormality detection circuit 62,
The inverter 64 outputs the abnormality detection timing signal d shown in (5) of FIG. 3, and the AND gate 70 outputs (2) of FIG.
The same signal as the signal a shown in is output. When the abnormality detection timing signal d rises, it is time to detect the abnormality,
Therefore, the time t1 is delayed from the trailing edge of the yarn presence signal when the weft insertion is normally performed, that is, when the weft yarn is not originally present.

When the weft insertion is normally performed, the flip-flop 72 takes in a high level signal at the rising edge of the signal d, but since the signal a is at a low level at this time, it is reset. Therefore, the low-level signal e shown in (6) of FIG. 3 is output. Therefore, the flip-flop 74 takes in the low-level signal e at the subsequent rise of the signal d, and thus outputs the signal f shown in (7) of FIG. Therefore, the signal indicating abnormality is not output.

Next, when the weft yarn is temporarily jammed in the feeler head 12, the signal a2 indicating the presence of the weft yarn continues to exist even after the weft insertion is completed and disappears at the same time as the next weft insertion. become. In this case, the flip-flop 72
Is the signal d in the weft inserting cycle in which the thread jam occurs.
Captures high level data at the rising edge of. At this time, since the signal a2 is at the high level, the flip-flop 72 is not reset, and (6) in FIG.
The high level signal e1 shown in FIG. Since the thread jam is cleared at the same time when the next weft insertion is completed, the signal a2 changes to the low level, the flip-flop 72 is reset, and the signal e1 also changes to the low level. Therefore, the flip-flop 74 takes in the low-level signal e at the rising edge of the signal d and outputs the low-level signal f shown in FIG. 3 (7). Therefore, no signal indicating an abnormality is output.

Next, if the sensor fails, the signal a3 indicating the presence of the weft thread will continue to exist after the end of weft insertion, and will continue to exist after the end of the next weft insertion. In this case, the flip-flop 72
First captures high level data at the rising edge of the signal d in the first weft inserting cycle. At this time, since the signal a3 is at high level, it is not reset and is shown in (6) of FIG. It outputs a high level signal e2.

Since the signal a3 is still at the high level at the rising edge of the signal d in the next weft insertion cycle, the flip-flop 72 is not reset and the signal e2 at the high level continues. Output. Therefore, the flip-flop 74 takes in the high level signal e2 at the rising edge of the signal d and outputs the high level signal f1 shown in (7) of FIG. This signal is sent to a control device (not shown) as a loom stop signal for stopping the loom. Therefore, the loom can be stopped immediately without performing the next weft insertion.

In the abnormality detecting circuit 76 shown in FIG. 4, a delay circuit 78 is arranged on the input side of the inverter 64 in order to further delay the timing at which an abnormality should be detected as compared with the case of the embodiment of FIG. The delay circuit 78 includes a variable resistor 80 and a capacitor 82.

The abnormality detection circuit 76 converts the timing signal b for weft detection shown in (3) of FIG. 5 into a signal b'shown in (4) of FIG. 5 which is delayed by a predetermined time t2 in the delay circuit 78, and this The operation is similar to that of the abnormality detection circuit of FIG. 1 except that the signal b ′ is converted by the inverter 64 into the abnormality detection timing signal shown in (5) of FIG. Therefore, the rising edge of the abnormality detection timing signal d (when detecting an abnormality) is further delayed from the falling edge of the yarn presence signal when weft insertion is normally performed.

As described above, by using the weft detection timing signal to further delay the timing of detecting an abnormality, it is possible to further improve the accuracy of the abnormality detection of the sensor. . That is, since the weft detection timing signal is for detecting the weft in the first place, the end timing thereof may overlap with the time when the weft originally exists in some cases. At this time, if the end time of the weft detection timing signal is used as the abnormality detection timing signal as in the embodiment of FIG. 1, the initial purpose cannot be achieved. Therefore, according to the embodiment of FIG. 4, by generating a delay signal by delaying the weft detection timing signal by a necessary time and using the end time of this signal as the abnormality detection timing signal, the abnormality detection timing signal is obtained. Is surely set at the time when the weft does not originally exist.

The end of this delay signal can be delayed until the start of the next weft insertion at the latest. That is,
By setting the generation timing of the abnormality detection timing signal at the latest until the start of the next weft insertion, it is possible to determine the abnormality of the weft detection device by the latest start of the next weft insertion and output the loom stop signal. And as a result,
It is possible to prevent the weft insertion after the abnormality is detected. The delay time can be adjusted by operating the variable resistor 80.

According to the embodiment of FIG. 4, since the abnormality detection timing signal is linked to the weft detection timing signal, even if the setting of the generation timing of the weft detection timing signal needs to be changed, Since it is not necessary to change the setting again when the abnormality detection timing signal is generated, the setting change operation becomes easy. Since this effect is due to the interlocking configuration, when configuring the weft detection device aiming only at this effect, the occurrence timing of the abnormality detection timing signal is simply set to the time when the weft does not originally exist as in the conventional case. Just set it.

The delay circuit 78 may be a circuit using at least one monostable multivibrator which is triggered at the rising or falling of the weft detection timing signal, instead of the resistor and the capacitor. Further, instead of using the flip-flop, another logic circuit such as an AND gate may be used to detect the abnormality.

In the above embodiment, the abnormality detection timing signal uses the conventional weft detection timing signal, but instead of this,
A dedicated abnormality detection timing signal generating means may be provided.

Further, in the above embodiment, in consideration of the temporary yarn clogging phenomenon, the weft yarn detecting device is started only when the cycle in which the yarn presence signal exists at the time of the abnormality detection timing signal occurs twice in succession. I decided to judge that it was abnormal. However, in the case of the weft yarn detecting device of the type in which such a temporary yarn clogging phenomenon does not pose a problem, when the yarn presence signal is present when the first abnormality detection timing signal is generated, it is immediately abnormal. May be determined.

Further, if necessary, it is judged that the weft yarn detecting device is abnormal only when the cycle in which the yarn presence signal exists at the time of generation of the abnormality detection timing signal reaches a predetermined occurrence frequency over a plurality of times. You may
That is, it is possible to count the number of cycles in which the yarn presence signal exists when the abnormality detection timing signal is generated, and to judge that there is an abnormality when the count value becomes equal to or larger than a predetermined value during a predetermined cycle. Further, if necessary, it may be determined to be abnormal when the cycle in which the thread presence signal exists at the time of generation of the abnormality detection timing signal continues for any number of times of 3 or more.

Further, in the above embodiment, the yarn presence signal when the weft yarn detecting device is abnormal is assumed to be continuous for convenience of explanation, but the present invention is not limited to this, and the yarn presence signal is intermittent. However, it can be treated in the same way. At this time, it is possible that the yarn presence signal based on the abnormality or the occurrence of the abnormality detection timing signal is absent, so in order to avoid this,
It is preferable to add a circuit for storing a yarn presence signal generated between the end of the weft yarn detection timing signal and the generation of the abnormality detection timing signal. Then, when this inter-thread yarn presence signal is generated, when the abnormality detection timing signal is generated, it is possible to determine that the weft detection device is abnormal and output the abnormality signal.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an electric circuit of a weft detection device of the present invention.

FIG. 2 is a diagram showing an embodiment of a sensor head used in the weft detection device of FIG.

FIG. 3 is a diagram showing a waveform of an electric signal in the weft detection device of FIG.

FIG. 4 is a block diagram showing another embodiment of the abnormality detection circuit.

5 is a diagram showing waveforms of electric signals in the abnormality detection circuit of FIG.

[Explanation of symbols]

10 Weft detection device 12 Feeler Head 16, 18 detector 24 weft 26 Reed b Timing signal for weft detection d Abnormality detection timing signal

Claims (5)

[Claims] 1. A weft insertion detecting means for determining that the weft insertion is normal when a yarn presence signal indicating the presence of a weft is present at a time specified by a weft detection timing signal,
An abnormality detection timing signal generating means for generating an abnormality detection timing signal from the end of the timing signal for weft detection to the start of the next weft insertion, and the yarn presence signal when the abnormality detection timing signal is generated. A weft detection device for a loom, including an abnormality detection unit that determines that the weft detection device is abnormal when present and outputs a loom stop signal. 2. The abnormality detection means determines that the weft detection device is abnormal when the cycle in which the yarn presence signal exists at the time of generation of the abnormality detection timing signal reaches a predetermined generation frequency over a plurality of cycles. The weft detection device according to claim 1, which outputs a weaving machine stop signal. 3. The abnormality detection timing signal generation means is means for generating a weft detection timing signal,
The weft detection device according to claim 1, wherein a signal at the end of the weft detection timing signal is used as an abnormality detection timing signal. 4. The abnormality detection timing signal generation means comprises means for generating a weft detection timing signal and means for converting the weft detection timing signal into a signal delayed for a predetermined period. The weft detection device described in 1). 5. The weft-insertion detecting means causes the weft thread to pass through the wetting thread while contacting the weft thread with the pair of detection bodies, and generates the thread presence signal when the weft thread comes into contact with the detection body. And a weft insertion detection circuit that determines that weft insertion is normal when the yarn presence signal is present at a time specified by the weft detection timing signal, and the abnormality detection means includes the abnormality detection timing signal. The weft detection device according to claim 1, wherein the weft detection device determines that the weft detection device is abnormal and outputs a loom stop signal when a plurality of cycles in which the yarn presence signal exists at the time of occurrence of the above-mentioned condition.