KR100341464B1 - Weaving detection device of the loom - Google Patents

Abstract

By inserting a reinforcement material 5 in the circumferential direction of the tire between the inner body ply 2 and the outer body ply 3 of the tire to reinforce the strength of the side wall, increase the shock absorbing power, improve ride comfort, steering stability and side wall thickness. It is a pneumatic tire that achieves the effect of preventing sidewall depression as well as reducing the deviation.

Description

Weft detection device of the loom

The present invention relates to a weft detecting apparatus for a loom for detecting the enclosed weft by optical detection means. As an optical weft detection device of a conventional loom, for example, as disclosed in Japanese Patent Publication No. 57-13653, a light emitter and a light receiver are disposed to face each other with a trajectory through which the weft thread passes when the weft is cut. It is known. This optical weft detecting device detects the weft by changing the output of the light receiver because the weft passes between the light emitter and the light receiver and the weft blocks light from the light emitter.

At this time, for example, in the case of a water jet loom, water is stored under the action of the surface tension of the transmitter and the receiver at a narrow interval. Bubbles are generated and these bubbles vibrate. Under the influence of this bubble vibration, the light receiving output of the light receiver varies irregularly with a frequency of about 20 Hz or less. According to the change in the light receiving output, the level change amount of the light receiving signal when the weft passes through also varies in proportion to the magnitude of the change output. That is, as shown in FIG. 6, if the weft passes when the light reception output is large due to the change in the light reception output, the amount of level change of the light reception signal at that time is relatively large (signal a), but the weft passes when the light reception output is small. Then, the level change amount of the received light signal at that time is relatively small (signal b). Therefore, the level change of the received signal when the weft passes through the fluctuation of the received light signal is not constant, so the S / N ratio of the weft detection signal is deteriorated.

In addition, as another type of optical weft detecting device of a loom, it is known to detect the presence or absence of the tip of the weft thread installed in the body. In this type of weft detecting device, the light receiving output of the light receiver changes not only with or without weft yarns but also due to vibration of the body. That is, in the case of the reflective weft detection device, for example, when the body vibrates according to the body stroke operation, the light reflecting surface of the dent vibrates, and thus the amount of incident light to the light receiver varies and thus the light receiving output is the body. Varies by the frequency corresponding to the oscillation frequency. Also, in the case of the transmission type weft detecting apparatus, when one of the light emitter and the light receiver is provided in the body, the light receiving output of the light receiver varies with the frequency corresponding to the vibration frequency of the body. In this case, the vibration frequency of the body is generally about 200 Hz or less. Therefore, in the same type of weft detection device as described above, the amount of change in the level of the received light signal when the weft is present varies in proportion to the magnitude of the variation output in the same way as the above-described weft detection device.

As described above, in the conventional optical weft detecting apparatus, since the light receiving output of the light receiver varies with the disturbance vibration frequency due to weaving operation such as the indentation operation or the body stroke operation, the level change amount of the light reception vibration indicating the presence of the weft yarn also depends on the variation output. It is affected by the fluctuation and worsens the S / N ratio of the weft detection signal.

At this time, as a countermeasure against electric signal fluctuations, it is common to provide a so-called AGC circuit for performing automatic gain control. However, in the case of the weft detection of the loom, there is a problem that the AGC function also acts on the weft detection signal indicating the presence of the weft, and the weft detection signal itself is extinguished, which further worsens the S / N ratio. Thus, as disclosed in Japanese Patent Laid-Open No. 2-46704, it has been proposed to operate the AGC function before the weft detection section, and to keep the gain constant during the weft detection section.

In order to remove only the disturbance vibration frequency component in the weft detection of the loom, as described in Japanese Patent Laid-Open No. 5-239743, the received signal passes through a band removing filter for removing a predetermined frequency component. It has also been proposed to discriminate signals.

However, the technique disclosed in Japanese Patent Laid-Open No. 2-46704 has a problem in that the structure of the control device becomes complicated because the timing of the AGC operation is controlled. In addition, in the technique disclosed in Japanese Patent Laid-Open Publication No. 5-239743, since only the disturbance vibration frequency component of the weft detection signal is removed, the problem of variation in the level change amount of the weft detection signal itself is not solved and dispersion occurs in the level change amount. Therefore, there is a problem that the S / N ratio is not greatly improved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and provides a weft detecting apparatus for a loom which can make the level change amount of the weft detecting signal indicating the presence of the weft constant and perform accurate weft detecting. The purpose.

The present invention includes a light emitter such as a light emitting diode or a lamp that emits light toward the weft of the body, and a light receiver such as a photodiode or a photo transistor that receives light from the light emitter, and outputs the light receiver to the light emitter. It is installed in the AGC circuit for feeding back and the return path of the AGC circuit and passes at least the same frequency component or lower frequency component as the disturbance vibration frequency due to the weaving operation of the light receiver. The present invention provides a weft detecting device for a loom equipped with a frequency filter that blocks frequency components.

In addition, the present invention is provided in the AGC circuit for feeding back the amplifier output of the receiver to the amplifier, and the disturbance vibration frequency is provided in the return path portion of the AGC circuit due to the loom operation of the output signal of the amplifier or It is a weft detection device for a loom provided with a frequency filter that passes at a lower frequency band and blocks at least frequency components of the weft detection signal.

In addition, the present invention is used in a water spray loom in which water is stored between the transmitter and the receiver, and the frequency filter passes only a frequency band equal to or lower than a frequency component of the fluctuation signal caused by the fluctuation of water. In addition, the transmitter and the receiver are installed in the body, the frequency filter passes a frequency component equal to or lower than the vibration frequency component of the body according to the body stroke operation. In addition, the frequency filter may be configured as a frequency filter for blocking a frequency component equal to or greater than the frequency component of the weft detection signal.

In the weft detection device of the loom according to the present invention, the signal input to the receiver is formed so that the AGC circuit functions by returning a frequency component equal to or lower than the disturbance vibration frequency according to the weaving operation of the loom among the output signals of the receiver. Since it is controlled to remove the disturbance vibration frequency due to the weaving operation of the loom, the output of the light receiver becomes almost constant output level other than the weft detection signal, so that the level change amount of the weft detection signal is also substantially constant. In addition, since the frequency identification of the weft detection signal is blocked and not fed back to the AGC circuit, the case of the weft detection signal itself does not occur.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described based on drawing.

1 to 4 show the first embodiment of the weft detection device of the loom of the present invention, and the weft detection device 11 of this embodiment shows the water jet loom as shown in FIGS. 2 and 3. It is disposed at the end face of the anticoagulation side, and is provided facing the one end of the body 12 through which the inclined 10 opened by the blind light (not shown) is inserted. An opening 12a is formed at one end of the body 12 between the lead plates 13 at the end of the body 12 to avoid interference with the weft detection device 11 when the body is being struck. In the opening of the weft yarn 10, the weft yarn 16, which is entrained by the water spray ejected from the entraining nozzle 14, is inserted through the predetermined timing.

The weft detecting device 11 of the embodiment has a filler main body 20 having a narrow slit 18 through which the enclosed weft thread can pass, and both pillar main bodies of the slit 18 with the slit 18 therebetween. 20 is provided in the detection part 21 which consists of a light-transmitting part and a light receiving part which are not shown in the figure which faced each other at the predetermined position of the weft-pass trajectory intermediate | middle of the slit 18. As shown in FIG. 1, the light transmitting portion and the light receiving portion of the detection unit 21 are each composed of a light emitter 23 such as a light emitting diode and a light receiver 25 such as a photodiode. Water is held in the detection part 21 of the slit 18 by the surface tension. And the pillar body 20 is fixed by the filler bracket 28 attached to the loom which is not shown in figure in order that the slit 18 may be located in the movement trace of the weft thread 16 which is body-cut.

The detection circuit of the weft detecting apparatus 11 of the above embodiment is provided so that the output of the driving amplifier 30 is connected to the light projector 23 so as to always emit light during the operation of the loom as shown in FIG. The light receiver 25 is connected to the input side of the amplifier 32 such as an operational amplifier. The output of the amplifier 32 is connected to the input terminal of the comparator 36 composed of an operational amplifier or the like via the differentiator 34 for detecting the signal change rate. In addition, a reference voltage having a predetermined threshold value is input to the other input terminal of the comparator 36. The output of the comparator 36 is connected to the AND gate 38, and a weft detection timing signal that repeats ON / OFF at a predetermined timing is connected to the AND gate 38 in response to the weaving operation of the loom (not shown). The ON section of the predetermined weft detection timing signal is a section including a time when the weft yarn 16 passes through the detection unit 21, and is, for example, a section from when the mouth is completed to the body stroke time.

The output of the amplifier 32 is fed back to the AGC amplifier 40 composed of an operational amplifier or the like. The AGC amplifier 40 constitutes an AGC circuit that performs automatic gain control. The AGC amplifier 40 receives an output difference between the Vref and the amplifier 32 by inputting a reference voltage Vref, and outputs the output of the amplifier 32 to the Vref. Outputs a converged control signal. The output of the AGC amplifier 40 is input to the amplifier 30 through the frequency filter 42. Therefore, the AGC circuit forms a feedback loop through the optical signal path through which the light emitted from the transmitter 23 is incident on the receiver 25.

The frequency filter 42 may be provided before or after the AGC amplifier 40. That is, the frequency filter 42 may be provided in the return environment of the AGC circuit. The frequency filter 42 is set at a cutoff frequency sufficient to pass a frequency component below the disturbance vibration frequency caused by the weaving operation of the loom among the output signals of the amplifier 32 and to block the frequency component of the weft detection signal. For example, in the water-jet loom of the above embodiment, the variation of the detection signal of the amplifier 32 generated when the water of the detection unit 21 oscillates due to vibration or the like is about 20 Hz, and the weft detection signal is about 1 kHz. The frequency is set to 72 Hz.

Next, the operation of the weft detecting apparatus 11 of the above embodiment will be described. First, during operation of the loom, light is always emitted from the light projector 23, and the light receiver 25 is always in a light receiving state, and outputs an output signal by light reception. In this state, when the weft yarn 16 is infiltrated at a predetermined upset timing and the body is struck by the body 12, the weft yarn 16 passes through the detection unit 21 of the slit 18. As a result, the weft yarn 16 cuts off the light from the transmitter 23, and the output signal of the receiver 25 is output via the amplifier 32. The output signal of the amplifier 32 is reduced only during the period in which the light is cut off, and the differential signal corresponding to the rate of change of the light receiving signal is output by the differentiator 34 so that the differential signal is input to the comparator 36 to provide a predetermined reference. Compared to voltage.

The output of the differentiator 34 compares the derivative value of the output of the light receiver 25 when the weft yarn 16 exits from the detector 21, that is, the rate of change of the leading edge, by the comparator 36. do. If the rate of change of the received signal is greater than or equal to the reference value according to the comparison result, it is determined that the weft is passed. If the output of the comparator 36 is a leading edge and is in the weft detection timing section, the false signal is output through the AND gate 38. When the weft detection timing signal is 0, the output of the AND gate is also 0, so that the false input signal is certainly not output in a section other than the weft detection section.

At this time, the output of the amplifier 32 has an AGC function by the feedback signal fed back to the AGC amplifier 40. In the AGC circuit, a frequency filter 42 is provided to pass only a frequency component of, for example, 72 Hz or less among the feedback signals as described above. Therefore, as shown in FIG. 4, the light receiving amount detected by the light receiver 25 is controlled so that the output of the light emitter 23 is controlled to remove the fluctuation of the light receiving amount caused by the shaking of the detection unit 21 as the injected water enters. Therefore, the light reception amount of the light receiver 25 becomes a substantially constant value except at the time of weft detection, and the output of the light receiver 25 also becomes constant. Therefore, in the detection of the weft yarn 16 in the weft detection section, the amount of change in the level of the weft detection signal when the receiver 25 detects the weft yarn is always a constant output.

According to the weft detection device 11 of the above embodiment, only the weft detection signal is prevented by reliably suppressing the fluctuation of the light reception signal due to the fluctuation of the water of the detection unit 21 due to the weaving operation of the loom at the time of the detection of the weft yarn 16. Since the S / N ratio of the signal is extremely good by the differential processing by the differentiator 34 outputted from the amplifier 32 in a clearly identifiable state, it is possible to accurately determine the weft by the comparator 36. Further, the weft detection signal is differentially processed, and the comparator 36 discriminates the signal when the weft thread exits from the detection unit 21 among the differential signals, thereby making it possible to clearly distinguish from the noise component. In addition, since the frequency component of the weft detection signal is cut off by the frequency filter 42 and is not fed back to the AGC circuit, the weft detection itself is not lost.

Next, the weft detection device of the second embodiment of the present invention will be described with reference to FIG. Here, the same reference numerals are used for the same members as those of the first embodiment, and description thereof will be omitted. The weft detection device 11 of the above embodiment has a light-receiving device 25 made of a phototransistor, and the AGC circuit using the frequency filter 42 whose output of the amplifier 32 is installed in the middle of the return path as in the first embodiment. It feeds back to the amplifier 32 of the light receiver 25 via the AGC amplifier 40 which constitutes.

The operation of the weft detection device 11 of the above embodiment is the same as the above embodiment, but the output of the light emitter 23 is constant, and the light receiving level of the light receiver 25 is determined by the detection of the detection part 21 by the injection of water. The fluctuations in the amount of light due to the fluctuation of water are displayed as the level fluctuation of the received signal. However, since the amplifier 32 performs AGC operation by the output vibration, the output of the amplifier 32 is such that fluctuation components below these disturbance vibration frequencies are removed.

That is, the output signal of the amplifier 32 passes through the frequency filter 42 to be a signal in which the frequency component according to the weft detection is blocked, including the disturbance vibration frequency component according to the fluctuation of water, and is input to the AGC amplifier 40. The AGC amplifier 40 calculates the difference between the input signal and the reference voltage Vref and outputs a control signal to which the input signal converges to the reference voltage Vref to the amplifier 32. The amplifier 32 gain-controls based on the control signal, so that its output is a signal of a substantially constant level from which a fluctuation component below the disturbance vibration frequency is removed.

In addition, in the signal amplification process of the amplifier 32, the weft detection signal is amplified by a gain corresponding to the level change of the light receiving signal, so that a signal having a substantially constant level change amount is made despite the level change of the light receiving signal. For example, when the received signal is small with respect to the reference voltage Vref, the superposition detection signal of the superimposed relatively small level change amount is amplified by a large gain, and conversely, when the received signal is large with respect to the reference voltage Vref, The weft detection signal of a large level change amount is amplified by a small gain. Therefore, as shown in Fig. 4, the light receiving output of the amplifier 32 is almost constant except for the weft detection signal, and the weft detection signal when the weft detection is detected is also output at a substantially constant value. In addition, since the frequency component of the weft detection signal is cut off by the frequency filter 42 and is not fed back to the AGC circuit, the weft detection signal itself is not lost.

The weft detection device 1 of the above embodiment can also obtain a weft detection signal with a high S / N ratio, and can accurately perform weft detection.

In addition, in the above embodiment, the weft detection device of the type shown in FIG. 2 has been described, but the present invention can also be applied to the weft detection device of the type installed on the body. In this case, the frequency filter passes a frequency component below the vibration frequency generated by the weaving operation of the loom, that is, the body cutting operation, and blocks at least the frequency component of the weft detection signal, thereby preventing the weft detection signal from being received by the vibration of the body. It is not affected by level fluctuations and becomes a signal of a substantially constant level change amount. In this case, since the fluctuation frequency of the output signal of the amplifier 32 due to body vibration is about 200 Hz or less and the weft detection signal is 2 kHz or more, the cutoff frequency of the frequency filter 42 may be set to, for example, about 500 Hz.

In addition, in the above embodiment, the weft detection device may be a reflection type in which a transmitter and a light receiver are arranged in parallel to the weft passage instead of the transmission type as shown in FIG. In addition, the light emitter may emit light only in a section necessary for weft detection, for example, in a section for inputting a weft detection timing signal, instead of always emitting light during operation of the loom. Similarly, the receiver may also be operated only in the sections required for the weft detection.

In the above embodiment, the output of the receiver amplifier is subjected to signal processing through a differentiator, a comparator and an end gate to determine the presence or absence of the weft, but other well-known signal processing may be performed instead of these circuits. For example, the comparator may use the differential signal when the weft enters the detection unit as the comparison target instead of the differential signal when the weft thread exits the detection unit among the differential signals. In addition, a comparator for comparing the output of the amplifier of the light receiver with a predetermined threshold may be provided, and it may be determined that there is a weft when the output of the amplifier exceeds the threshold.

The cutoff frequency of the frequency filter may be set to a frequency lower than that of the weft detection signal. In this case, the AGC circuit operates on all noise components other than the weft detection signal. In addition, the AGC action may be operated only for a specific frequency band. For example, the frequency filter may be a band pass filter that allows the vibration frequency band of the body, the fluctuation band of water of the detection unit, or a loom or other vibration frequency band to pass. It is sufficient to feed back the signal in the frequency band as a noise component due to the weaving operation of the loom at least in the AGC circuit.

The weft detection device of the loom according to the present invention can reliably suppress fluctuations in the light reception signal caused by the weaving operation of the loom in the detection of the weft yarn, and can make the level fluctuation of the output during the weft detection constant. The signal itself does not disappear, and only the weft detection signal becomes clearly identifiable, so that the settling can be determined. Therefore, accurate detection of the weft without detecting the detection of the weft is possible.

1 is a weft detecting circuit diagram of the first embodiment of the weft detecting apparatus of the present invention;

2 is a partial perspective view showing the weft detecting apparatus of the embodiment;

3 is a plan view showing the weft detecting apparatus of the embodiment.

4 is a graph showing the light reception amount of the light receiver of the embodiment.

5 is a detection circuit diagram of a second embodiment of the weft detecting apparatus of the present invention.

6 is a graph showing the light receiving amount of a conventional light receiver.

Claims (10)

A light emitter that emits light toward the body weft thread, a light receiver that receives light emitted from the light emitter, an AGC circuit that feeds back the output of the light receiver to the light emitter, and an ear path of the AGC circuit And a frequency filter for blocking the frequency component of the weft detection signal by passing only a frequency equal to or lower than the disturbance vibration frequency caused by the weaving operation of the light receiver among the output signals of the receiver. . The loom of claim 1, wherein the loom is a water jet loom, and the frequency filter is a frequency filter that passes a frequency band equal to or lower than a frequency of a fluctuating signal caused by fluctuation of water existing between the light emitter and the light receiver. Weft detection device of a loom characterized in that. The loom of claim 1, wherein the transmitter and the receiver are installed in a body, and the frequency filter is a frequency filter for passing a frequency of a band equal to or lower than a frequency of body vibration caused by a body stroke operation. Weft detection device. The weft detecting apparatus of claim 1, wherein the frequency filter is a frequency filter that cuts a frequency component equal to or greater than a frequency of the weft detection signal. The weft detecting apparatus for a weaving machine according to claim 1, further comprising a comparator for comparing the differentiator input to the output of the light receiver with the output of the differentiator to perform weft detection. A light emitter for emitting light toward the body weft thread, a light receiver for receiving light emitted from the light emitter, an AGC circuit for feeding back the output of the light receiver to an amplifier of the light receiver, and a return of the AGC circuit It is installed in the path portion of the output signal of the receiver and the disturbance vibration frequency caused by the weaving operation of the loom, or a frequency filter of the lower band through the frequency filter to cut at least the frequency component of the weft detection signal, characterized in that it is installed Weft detection device of the loom. The loom of claim 6, wherein the loom is a water jet loom, and the frequency filter is a frequency filter for passing a frequency component of a fluctuation signal due to fluctuation of water existing between the light emitter and the light receiver or a frequency component of a lower band. Weft detection device of a loom characterized in that. 7. The loom according to claim 6, wherein the transmitter and the receiver are installed in a body, and the frequency filter is a frequency filter for passing a frequency component of body vibration or a lower frequency band component according to the body stroke operation. Weft detection device. 7. The weft detecting device of claim 6, wherein the frequency filter is a frequency filter that cuts a frequency component of a weft detection signal or a frequency component of a lower band. 7. The weft detecting device of claim 6, further comprising: a comparator for comparing the output of the light receiver with the output of the differentiator and performing a weft detection by comparing the output of the differentiator.