JP5350917B2 - Yarn running monitoring device - Google Patents

Description

  The present invention relates to an apparatus for monitoring the running of a yarn during operation of a textile machine such as a sewing machine, a knitting machine, or a winder.

  Conventionally, the running of the yarn is monitored during operation of the sewing machine. The production yield can be improved by monitoring the skipping occurring during the production of clothing and the like. In order to monitor the yarn length and yarn speed of a running yarn, the occurrence of yarn breakage or the occurrence of stitch skipping, a method of winding the yarn around a roller is often used. In this method, the running state of the yarn is monitored by detecting the number of rotations of the roller that rotates with the yarn.

  In the method of winding the yarn around the roller, irregular slipping or friction occurs between the yarn and the roller. Therefore, since the rotational speed of the roller does not change proportionally with respect to the traveling amount of the yarn, it is difficult to accurately monitor the yarn length, yarn speed, yarn breakage, stitch skipping, and the like. Since it is necessary to obtain energy for rotating the roller by running the yarn, it is necessary to pull the yarn with an extra tension corresponding to the energy, and there is a problem that the tone of the sewing machine becomes worse. In addition, since the roller has a rotating sliding portion, there is a drawback in that the rotating sliding portion accumulates cotton dust or the like and does not rotate.

  Patent Document 1 below discloses a winding device that uses a differential spatial filter element. The shadow of the running yarn fluff is projected onto the differential spatial filter element, and the photoelectric current photoelectrically converted by the spatial filter element is signal-processed.

  However, the device of Patent Document 1 is a winding device that measures the winding length of the yarn, and is not a device that monitors the running of the yarn. Moreover, since the shadow of the yarn fluff projected on the differential spatial filter element is used, the method cannot be applied to yarn without fluff.

Japanese Patent Laying-Open No. 2005-194024 (paragraph number 0015, FIG. 1, etc.)

  An object of the present invention is to provide an apparatus capable of accurately detecting a running abnormality of a yarn such as a skip of a sewing machine without contact.

  The yarn traveling monitoring apparatus of the present invention includes a light source that irradiates light to the yarn and a light receiving element that has a light receiving surface that receives light from the light source. When the yarn travels between the light source and the light receiving surface and the position of the yarn changes in a direction parallel to the light receiving surface, the photoelectric current photoelectrically converted by the light receiving element changes.

  When the yarn travels, the yarn is blurred in a plurality of directions. When the yarn is shaken in the direction parallel to the light receiving surface, the photoelectric current photoelectrically converted by the light receiving element changes.

  The light receiving element may change the width of the light receiving surface in the parallel direction. Furthermore, the light source may be a linear light source facing the parallel direction, and the amount of light may be changed in the parallel direction.

  When the traveling yarn is shaken in the parallel direction with respect to the light receiving surface, the photocurrent changes in the previous period. By detecting the change in the photocurrent, the running of the yarn can be monitored.

  Means for generating a first pulse corresponding to a change in the value of the photocurrent, means for counting the number of the first pulses, and means for determining a running abnormality of the yarn based on the number of the first pulses. . The yarn running abnormality is determined by counting the number of first pulses.

  The means for emitting the second pulse according to the operation of the means for running the yarn is compared with the timing of the first pulse and the second pulse, and the yarn running according to the operation of the means for running the yarn. Means for determining an abnormality. Whether the running of the yarn is synchronized with the operation of the textile machine is determined to determine whether the running of the yarn is abnormal.

  According to the present invention, it is utilized that when the yarn travels, the yarn is blurred and the position of the yarn changes in a direction parallel to the light receiving surface. Because of the movement in the parallel direction, it is possible to monitor the running abnormality regardless of the presence or absence of yarn fluff. Furthermore, since the width of the light receiving surface of the light receiving element and the light amount of the light source are changed in the parallel direction, the change in the value of the output photocurrent is likely to be large, and it is easy to determine a running abnormality.

It is a figure which shows the structure of the traveling monitoring apparatus of the thread | yarn of this invention. It is a figure which shows a light receiving element, (a) is a side view, (b) is a top view, (c) is a figure which shows the movement of a shadow. It is a figure which shows the relationship between the output which carried out the current voltage conversion of the photocurrent, and the operation | movement of a proximity switch. It is a graph which shows the relationship between a 1st pulse and a 2nd pulse. It is a figure which shows the structure which changed the width | variety of the light-receiving surface of a light receiving element. It is a figure which shows the structure which changed the emitted light quantity of the light source. It is the figure which applied the thread running monitoring device to the sewing machine. It is the figure which arranged the several light receiving element.

  The yarn traveling monitoring apparatus of the present invention will be described with reference to the drawings. The yarn traveling monitoring device is attached in the middle of the yarn traveling route of the textile machine. Examples of the textile machine include a sewing machine, a knitting machine, and a winder.

  As shown in FIG. 1, the travel monitoring apparatus 10 includes a light source 14 that irradiates the yarn 12 with light L, a light receiving element 16 that is disposed in the direction opposite to the light source 14 with respect to the yarn 12, and a light receiving element 16 And a control circuit 18 for determining a running abnormality of the yarn 12 based on the output of.

  The yarn 12 to be monitored for traveling may or may not have the fluff 13. The yarn 12 having the fluff 13 is a cotton yarn or the like. Examples of the yarn 12 having no fluff 13, that is, a filament yarn, include a silk yarn as a natural yarn and a nylon yarn and a polyester yarn as a chemically synthesized yarn.

  The light source 14 irradiates the traveling yarn 12 with light L. The light source 14 uses a light emitting diode or a laser diode. The light L emitted from the light source 14 can project the shadow of the yarn 12 on the light receiving surface 20 of the light receiving element 16. When the yarn 12 is not present, the light source 14 irradiates the entire light receiving surface 20 of the light receiving element 16 with the light L having a uniform light amount.

  The light receiving element 16 photoelectrically converts the light L and outputs a photocurrent. Since the yarn 12 travels between the light source 14 and the light receiving element 16, the shadow of the yarn 12 is projected onto the light receiving element 16. The shadow of the yarn 12 is projected onto the light receiving surface 20. As the position and size of the shadow of the yarn 12 changes, the value of the photoelectric current photoelectrically converted by the light receiving element 16 changes. The yarn 12 travels in a direction determined by the textile machine, but travels while causing blurring not only in the traveling direction but also in the direction perpendicular to the traveling direction during traveling. The present invention utilizes the fact that the position and size of the shadow of the yarn 12 changes due to this blur, and the value of the photocurrent photoelectrically converted by the light receiving element 16 changes. The configuration will be described below.

  In addition, as shown in FIG. 1, let the running direction of the thread | yarn 12 be a y direction. The direction perpendicular to the y direction and the direction in which the light L is emitted is defined as the z direction. The light source 14, the yarn 12, and the light receiving element 16 are arranged in the z direction. Also, the direction perpendicular to the y direction and the z direction is taken as the x direction. The light receiving surface 20 is in the xy plane. The blur of the yarn 12 has an x-direction component and a z-direction component, and the present invention uses the x-direction component.

  The light receiving element 16 has a PIN type photodiode structure as shown in FIGS. The light receiving element 16 may have a PN type photodiode structure. The light receiving surface 20 is a P layer, which is a light receiving layer and a resistance layer. The light receiving surface 20 is rectangular and has a pair of anode electrodes T1 and T2 at both ends thereof. Each of the anode electrodes T1 and T2 is an output electrode that outputs a photoelectric current photoelectrically converted by the light receiving surface 20. The opposite surface of the light receiving surface 20 is an N-type high-resistance silicon substrate (N layer) and has a cathode electrode T3.

  Photocurrent is generated when the light receiving surface 20 is irradiated with the light L. In the present invention, since there is a shadow S1 of the yarn 12 as shown in FIG. 2C, a photocurrent is generated from a position without the shadow S1.

Here, the light receiving surface 20, when the value of the resistance is uniform resistive layer, spot light L is to have been irradiated in the position moved in the direction of the distance X _A only electrodes T2 from the center of the light receiving surface 20. At this time, the photocurrent output from the first anode electrode T1 is I _x1 , the photocurrent output from the second anode electrode T2 is I _x2 , the total current is Io (sum of I _x1 and I _x2 ), and the light receiving surface 20 Is the length Lx. In this case, the following formulas 1 and 2 are satisfied.

  According to Equations 1 and 2, when the light receiving surface 20 is irradiated with the light L, the total current Io is divided according to the irradiation position, and a photocurrent is output from each of the electrodes T1 and T2. Further, when photocurrents are generated at a plurality of locations, the photocurrents are combined. In the case of the present invention, a photocurrent is generated from a portion other than the shadow S1 of the yarn 12.

As the yarn 12 travels, blurring occurs, and the blur component includes an x-direction component that is a parallel component to the light receiving surface 20. For example, the shadow S1 moves as shown in FIG. 2C, and I _x1 and I _x2 change. By taking the difference between I _x1 and I _x2 , it is possible to monitor the state in which the yarn 12 travels while shaking in the x direction.

  In order to obtain a difference in photocurrent, a differential circuit 22 using an operational amplifier or a resistor is used. In the differential circuit 22, the photocurrent output from the anode electrodes T 1 and T 2 is converted into a current voltage, and then the differential between both voltages is output.

  The control circuit 18 includes an amplifier circuit and a determination circuit. The amplifier circuit is a circuit that converts a differential signal output from the differential circuit into a first pulse, and is configured by circuit elements such as an operational amplifier, a resistor, and a capacitor. The determination circuit is a circuit for determining a running abnormality of the yarn 12 based on the presence or absence of the first pulse, and is configured by a sequencer, a microcomputer, or the like. Specifically, the differential signal is passed through a band-pass filter by an amplifier circuit to shape the waveform, and further amplified and converted to a first pulse that is a waveform equal to or greater than a threshold value stored in advance. The determination circuit counts the number of first pulses. If there is a predetermined number of first pulses in a predetermined time, it is determined that the yarn 12 is traveling, and if there is no first pulse, it is determined that the yarn 12 is not traveling. The running abnormality of the yarn 12 can be easily determined based on whether or not there is a predetermined number of first pulses within a predetermined time.

  If it is determined that the yarn 12 is not running, a signal may be sent from the control circuit 18 to the alarm device to issue an alarm. In addition, a signal may be sent from the control circuit 18 to a sequencer that controls the operation of the textile machine to stop the operation of the textile machine.

  A proximity switch 24 or the like is attached to the means for running the yarn 12 of the textile machine. For example, the proximity switch 24 is attached to a handle of a sewing needle that operates at a fixed timing and a mechanism that moves the handle. The proximity switch 24 emits an on / off signal according to the operation of the handle of the sewing machine.

  For example, when the yarn 12 is traveling in accordance with the operation of the textile machine, the relationship between the ON / OFF timing of the proximity switch 24 and the output of the differential circuit 22 is the same as shown in FIG. Become. If this is utilized, the control circuit 18 compares the timing of the second pulse generated by turning on / off the proximity switch 24 with the first pulse generated by the photocurrent of the light receiving element 16, and the yarn 12. Whether or not the yarn 12 is traveling can be determined according to the operation of the means for traveling the yarn. As shown in FIG. 4, it is possible to determine whether or not the running of the yarn 12 and the operation of the textile machine are the same only by determining the timing of the first pulse and the second pulse.

  In some cases, the yarn 12 travels with a certain delay from the operation of the mechanism that moves the handle of the sewing needle. Even in such a case, if a second pulse is generated by turning on / off the proximity switch 24, a pulse train of the first pulse by the output of the light receiving element 16 is generated. The control circuit 18 makes the determination in consideration of the timing difference between the pulse trains of the second pulse and the first pulse.

  As described above, the present invention monitors the running of the yarn 12 using the blurring when the yarn 12 runs. Regardless of the presence or absence of the fuzz 13 of the yarn 12, the running state can be monitored by the yarn 12 moving in the x direction during running. By changing the photocurrent in the direction perpendicular to the running direction of the yarn 12, the running of the yarn 12 can be reliably monitored.

  As mentioned above, although embodiment of this invention was described above, this invention is not limited to said embodiment. As shown in FIG. 5, it may be a monitoring device 10b in which the area of the light receiving surface 20b of the light receiving element 16b is changed. The area is such that the width of the light receiving surface 20 changes in the x direction. In FIG. 5, the width of the light receiving surface 20 increases as it approaches the first electrode T1. By changing the width of the light receiving surface 20, the difference between the photocurrents output from the electrodes T1 and T2 increases, and the value of the differential signal can be increased.

  Further, as shown in FIG. 6, the monitoring device 10c may be configured such that the width of the light receiving surface 20 of the light receiving element 16 is constant and the amount of light emitted from the light source 14b is changed in the x direction. The light source 14b has a line shape. The longitudinal direction of the light source 14b is set to the x direction. For example, the amount of emitted light is reduced by moving closer to the first electrode T1 side. In order to change the amount of emitted light, the light amount may be adjusted by arranging light emitting diodes having different amounts of emitted light in a line, or arranging a dimming film on the emission side of the light source 14b. By changing the amount of emitted light, the change in the value of the photocurrent caused by the light receiving position can be increased.

  Although it has been described that the x-direction component of the blur of the yarn 12 is used, the shadow of the yarn 12 on the light receiving surface 20 is blurred in the x-direction and the photocurrent changes even in the z-direction. There is. Therefore, even if the yarn 12 changes in the z direction, the running of the yarn 12 can be monitored.

  As shown in FIG. 7, the sewing machine 30 or the like has a needle thread 12a. In such a case, you may provide the monitoring apparatus 10 provided with said light source 14, the light receiving element 16, and the control circuit 18 with respect to the needle thread 12a.

  The monitoring device 10 may be provided on the lower thread without being limited to the needle thread 12a. Further, the monitoring device 10 may be provided on both the needle thread 12a and the lower thread.

  As shown in FIG. 8, the light receiving elements 16 a, 16 b, and 16 c may be arranged in the running direction of the yarn 12. A first pulse is generated from the photocurrents of the plurality of light receiving elements 16a, 16b, 16c so that the running state of the yarn 12 can be reliably monitored. When the differential circuit 22 generates a differential signal, the average value or the total value of the photocurrents output from the electrodes T1 and T2 of the plurality of light receiving elements 16a, 16b, and 16c is used.

  The yarn 12 is not a combination of a plurality of short fibers, and may be a long fiber having no fluff and unevenness on the surface.

  In the above description, the difference between the photocurrents of the anode electrodes T1 and T2 is obtained by the differential circuit 22 and input to the control circuit 18. However, only the photocurrent of one of the anode electrodes T1 and T2 may be used. . Due to the blurring of the yarn 12, even if only one of the anode electrodes T1 and T2 is changed, the photocurrent is changed.

  As long as the proximity switch 24 generates an electrical signal in accordance with the operation of the textile machine that travels the yarn 12, another non-contact sensor may be used.

  In addition, the present invention can be carried out in a mode in which various improvements, modifications, and changes are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

10: Travel monitoring device 12: Yarn 13: Fluff 14: Light source 16: Light receiving element 18: Control circuit 20: Light receiving surface 22: Differential circuit 24: Proximity switch 30: Sewing machine

Claims (3)

A light source that illuminates the yarn,
A light receiving element having a light receiving surface for receiving light from the light source;
With
A yarn running monitoring device in which a photoelectric current converted by a light receiving element changes when a yarn runs between the light source and the light receiving surface and the position of the yarn changes in a direction parallel to the light receiving surface. In
Means for generating a first pulse corresponding to a change in the value of the photocurrent;
Means for counting the number of said first pulses;
Means for determining a running abnormality of the yarn according to the number of the first pulses;
Means for emitting a second pulse in response to the operation of the means for running the yarn;
Means for comparing the timings of the first pulse and the second pulse, and determining a running abnormality of the yarn according to the operation of the means for running the yarn;
A travel monitoring device comprising: The travel monitoring device according to claim 1, wherein the light receiving element has a light receiving surface whose width changes in the parallel direction. The travel monitoring apparatus according to claim 1, wherein the light source is a linear light source facing in the parallel direction, and the amount of light changes in the parallel direction.

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