JP5096180B2 - Yarn running monitoring device - Google Patents

Description

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

  Conventionally, a running yarn is monitored while a textile machine such as a sewing machine, a knitting machine, or a winder is in operation. The purpose is to improve the manufacturing yield by monitoring the skipping during the production of clothing and the like. When monitoring the yarn length and yarn speed of a running yarn, the occurrence of yarn breakage, or the occurrence of stitch skipping, there is a method in which the yarn is wound around a roller. 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. Since the number of rotations of the roller with respect to the running of the yarn is not constant, it is impossible to accurately monitor the yarn length, yarn speed, yarn breakage, stitch skipping, and the like. Since the energy for rotating the roller is obtained by running the yarn, it is necessary to pull the yarn with excessive tension. Since the roller has a rotary sliding portion, cotton dust or the like accumulates in the rotary sliding portion and does not rotate.

  Patent Document 1 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. Since the apparatus of Patent Document 1 detects the movement of the yarn fluff, there is no problem as long as it is a cotton yarn with fluff. However, in the case of a filament yarn having no fluff or almost no fluff, the running state cannot be monitored, and the yarn is wound up in a state where the running cannot be monitored.

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

  Therefore, an object of the present invention is to provide an apparatus capable of monitoring the running of a filament yarn in which fluff is absent or almost absent.

  The yarn traveling monitoring device of the present invention is a light source that irradiates light to the yarn, and is disposed in a direction opposite to the light source with respect to the yarn, and two light receiving elements have the same pitch in the traveling direction of the yarn. And a differential spatial filter element that outputs a photocurrent corresponding to a change in the shadow of the yarn irradiated with light. The yarn is a filament yarn, and the pitch of the light receiving elements is substantially the same as the distance from the concave to the concave or the distance from the convex to the convex on the surface of the yarn. These distances include an average value of the distances from the concave to the concave of the plurality of concaves and convexes on the surface of the yarn, an average value of the distances from the convex to the convexes, or an average value of both distances.

  A thread runs between the light source and the differential spatial filter element. The shadow of the yarn is projected on the differential spatial filter element by the light of the light source. If the pitch of the light receiving elements is substantially the same as the distance between the concaves and convexes on the surface of the yarn, or the distance from the convexes to the convexes, the phases of the photocurrents output from the two light receiving elements are 180 degrees to each other. Shift. Since the output of the differential spatial filter element is a differential output, two series of outputs are output without cancellation.

  The travel monitoring device includes a signal processing circuit having means for converting into a pulse corresponding to the value of the photocurrent of the differential spatial filter element, and means for determining whether or not the yarn is traveling based on the presence or absence of the pulse. When the yarn travels, a pulse is generated from the output of the differential spatial filter element, and the presence or absence of the yarn is determined from the presence or absence of the pulse.

  A proximity switch that is turned on and off according to the operation of the means for causing the textile machine to run the yarn is attached. The signal processing circuit compares the timing of the pulse generated by the on / off of the proximity switch and the pulse generated by the photocurrent of the differential spatial filter element, and according to the operation of the means for running the yarn And means for determining whether the yarn is running. It is determined whether the yarn is running according to the operation of running the yarn of the textile machine.

  The pitch of the light receiving elements is 50 to 500 μm. The filament yarn includes a chemically synthesized yarn.

  In the present invention, by making the pitch of the light receiving elements substantially the same as the size of the fine unevenness, the outputs of the two series of light receiving elements are not canceled, and the output due to the fine unevenness can be taken out. Even if there is no fluff on the yarn, the output of the differential spatial filter element can be obtained from the unevenness of the yarn, so that it is possible to monitor the running of the filament yarn that could not be monitored conventionally.

  The yarn traveling monitoring apparatus of the present invention will be described with reference to the drawings. The traveling monitoring device of the present invention is attached in the middle of the traveling path of the yarn of the textile machine. The yarns that are monitored for running are filament yarns that have no or little fluff. Examples of the filament yarn include silk yarn as natural yarn and nylon yarn and polyester yarn as chemically synthesized yarn. Hereinafter, the filament yarn used for explanation is mainly a chemically synthesized yarn.

  A yarn (filament yarn) is a combination of a plurality of long fibers. The surface of the long fiber looks like a smooth surface with no irregularities by visual observation, but has fine irregularities on the surface when magnified by a microscope or the like (see FIG. 4). The fine irregularities are present in a certain size range depending on the production conditions, environmental conditions, physical properties of raw materials, and the like when the long fibers are spun. That is, on the surface of the yarn 12, the fine irregularities 26 of the long fibers are present in a certain size range.

  A traveling monitoring apparatus 10 according to the present invention shown in FIG. 1 includes a light source 14 that irradiates a traveling yarn 12 with light L, and a differential spatial filter element that is disposed in a direction opposite to the light source 14 with respect to the yarn 12. 16 and a signal processing circuit 18 for determining whether or not the yarn 12 is traveling from the output of the differential spatial filter element 16.

  The light source 14 uses a light emitting diode or a laser diode. The light L emitted from the light source 14 has a luminance that can project the brightness of the shadow due to the fine irregularities 26 of the yarn 12 on the differential spatial filter element 16. For example, a high output with a light emission output of 10 mW or more is good.

  The differential spatial filter element 16 includes a plurality of light receiving elements 20a and 20b. Examples of the light receiving elements 20a and 20b include, but are not limited to, pn photodiodes and pin photodiodes. The plurality of light receiving elements 20a and 20b are divided into two series A and B, and each of the series A and B has a plurality of light receiving elements 20a and 20b. As shown in FIG. 2, the light receiving elements 20a and 20b of the two series A and B are alternately arranged in the running direction z of the yarn 12 at the same pitch d1. An equivalent circuit of the differential spatial filter element 16 is shown in FIG. 3, and the cathodes of the light receiving elements 20a and 20b are short-circuited for each of the series A and B to form a comb shape. In the differential spatial filter element 16, photocurrents are output as series A output and series B output from the anodes of both series A and B, and sent to the differential amplifier circuit 22. In the differential amplifier circuit 22, the series A output and the series B output are further differentially amplified and sent to the signal processing circuit 18.

  In the present invention, in order to monitor the traveling of the filament yarn 12, the pitch d1 of the light receiving elements 20a and 20b is made substantially the same as the size of the fine irregularities 26 on the surface of the filament yarn 12. This will be described below.

  (1) In the differential spatial filter element 16, the light receiving elements 20a and 20b of two series A and B are alternately arranged at the equal pitch d1. (2) The output of the differential spatial filter element 16 is affected by the shadow of the fine irregularities 26 of the yarn 12 projected onto the light receiving elements 20a and 20b. (3) The output of the differential spatial filter element 16 is a differential output. From the above (1) to (3), if both the light receiving elements 20a and 20b of the series A and the series B have the same received light amount, the outputs of the light receiving elements 20a and 20b are cancelled. If the light receiving elements 20a and 20b of the series A and the series B have different received light amounts, a differential output is generated. Note that the received light amounts in the series A and B are averaged or all added.

  If the fine irregularities 26 of the yarn 12 have different sizes with respect to the pitch d1, the received light amounts of the light receiving elements 20a and 20b of both series A and B will be the same or substantially the same. Specifically, even if the light receiving amounts are different between the adjacent light receiving elements 20a and 20b, the light receiving amounts of the light receiving elements 20a and 20b for the series A and B are the same or substantially the same. The outputs of both series A and B are the same or substantially the same, and the differential output of the differential spatial filter element 16 is 0 or substantially 0.

  If the interval between the concave portions or the convex portions of the fine unevenness 26 is the same as or substantially the same as the pitch d1, the phase of the amount of light received by the light receiving element 20a of the series A and the light receiving element 20b of the series B is shifted by 180 degrees. It becomes. For example, when a shadow due to the concave portion of the yarn 12 is projected onto the light receiving element 20a, a shadow due to the convex portion of the yarn 12 is projected onto the light receiving element 20b, and the received light amount corresponding thereto is received. For example, if the shape of the fine unevenness 26 is substantially uniform, the series A and the series B have almost the same received light amount alternately. Therefore, the differential spatial filter element 16 performs a differential output corresponding to almost double the photocurrent of the light receiving elements 20a and 20b of the series A or the series B.

  Further, even if the shape of the fine irregularities 26 is somewhat non-uniform, since there are a plurality of light receiving elements 20a and 20b in each of the series A and B, the total amount of received light for each of the series A and B is almost the same alternately. Become. Accordingly, in this case as well, the differential spatial filter element 16 performs a differential output corresponding to almost double the photocurrent of the light receiving elements 20a and 20b of the series A or the series B.

  As described above, in order to differentially output the photocurrents of the light receiving elements 20a and 20b caused by the shadows of the fine irregularities 26 of the yarn 12, the pitch d1 of each of the light receiving elements 20a and 20b is set to the fine irregularities 26 of the yarn 12. The light receiving elements 20a and 20b may be alternately arranged at equal intervals. Therefore, the pitch d1 is set to be substantially the same as the distance d2 from the concave portion to the concave portion of the fine unevenness 26 on the surface of the yarn 12, or the distance d3 from the convex portion to the convex portion. For example, the pitch d1 is 50 to 500 μm, and 50 to 300 μm is preferable among them. As the distances d2 and d3, average values may be used as will be described later.

  The output of the differential spatial filter element 16 is processed by a signal processing circuit 18 composed of circuit elements such as an operational amplifier, a resistor, and a capacitor. The signal processing circuit 18 includes a circuit that converts a pulse corresponding to the value of the photocurrent of the differential spatial filter element 16 and a circuit that determines whether or not the yarn is running based on the presence or absence of the pulse. Specifically, the output signal from the differential amplifier circuit 22 is input, the waveform is shaped through a band-pass filter, further amplified and converted into a pulse train that is greater than or equal to a threshold value stored in advance, and the number of pulses in the pulse train Count. If there is a predetermined number of pulses in a predetermined time, it is determined that the yarn 12 has traveled, and if there is no pulse, it is determined that the yarn 12 has not traveled. The presence or absence of running of the yarn 12 can be easily determined only by the presence or absence of a pulse indicating whether or not there is a predetermined pulse within a predetermined time.

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

  The signal processing circuit 18 may include a circuit that calculates the running yarn length of the yarn 12 from the total number of pulses during the operation time and the yarn speed from the number of pulses per unit time. Not only the presence or absence of running of the yarn 12 but also the running state of the yarn 12 can be known. The calculated running yarn length and yarn speed data of the yarn 12 may be fed back to a sequencer that controls the operation of the textile machine. From the fed back data, the sequencer can modify the operation of the textile machine.

  A proximity switch 24 or the like is attached in the vicinity of the means for running the yarn 12 of the textile machine. For example, the proximity switch 24 is attached in the vicinity of a handle of the sewing needle that operates at a fixed timing, a mechanism for moving the handle, or the like. The proximity switch 24 emits an on / off signal according to the operation of the handle of the sewing machine. The signal processing circuit 18 compares the timing of the pulse generated by turning on / off the proximity switch 24 with the pulse generated by the photocurrent of the differential spatial filter element 16, and travels the yarn 12. A circuit for determining whether or not the yarn 12 is traveling in accordance with the operation of is included. It is possible to check whether or not the running of the yarn 12 and the operation of the textile machine are the same only by checking whether or not the timing of the pulses is the same. For example, if the yarn 12 is traveling normally, the pulse generated by turning on / off the proximity switch 24 and the pulse train generated by the output of the differential spatial filter element 18 are at substantially the same time and at the same time interval as shown in FIG. Is turned on.

  Note that the yarn 12 may travel with a certain delay with respect to the operation of the mechanism that moves the handle of the sewing needle. Even in such a case, if one pulse is generated by turning on / off the proximity switch 24, one pulse train is generated by the output of the differential spatial filter element 18. The signal processing circuit 18 performs determination in consideration of a certain timing shift between the pulse and the pulse train. In FIG. 5, although the output of the differential spatial filter element 18 is a pulse train, the pulse train is determined as one pulse. In FIG. 5, a pulse and a pulse train are shown. However, depending on the operation of the mechanism detected by the proximity switch 24 and the size of the unevenness 26 of the yarn 12, the pulse and the pulse may be used.

  As mentioned above, although embodiment of this invention was described above, this invention is not limited to said embodiment. The yarn 12 shown in FIG. 4 has fine irregularities 26 having a certain range of sizes, but the actual yarn 12 does not necessarily have the minute irregularities 26 having a certain range of sizes. Therefore, the above-mentioned distances d2 and d3 are the average value of the distances from the concave to the concave of the plurality of fine irregularities 26 on the surface of the yarn 12, the average value of the distances from the convex to the convex, or the average of both distances. Include a value. Further, a representative value may be used from a plurality of distances d2 and d3 without using the average value.

  As illustrated in FIG. 4, the yarn 12 in which a plurality of long fibers are further combined has been described, but a single wire having no fluff and unevenness on the surface may be used.

  The signal processing circuit 18 may be not only a circuit element such as an operational amplifier but also a circuit including software as necessary. A non-contact sensor other than the proximity switch 24 may be used as long as an electrical signal is generated in accordance with the operation of the mechanism that causes the yarn 12 to travel.

  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 gist thereof.

It is a figure which shows the structure of the traveling monitoring apparatus of a yarn. It is a figure which shows a mode that a light receiving element is located in a line with the same pitch. It is an equivalent circuit of a differential type spatial filter element. It is an enlarged view of a yarn without fluff. It is a figure which shows the pulse in a signal processing circuit, the upper is a pulse train by a proximity switch, and the lower is a pulse by the output of a differential type spatial filter element.

Explanation of symbols

10: Yarn running monitoring device 12: Yarn (filament yarn)
14: Light source 16: Differential type spatial filter element 18: Signal processing circuit 20a, 20b: Light receiving element 22: Differential amplifier circuit 24: Proximity switch 26: Fine unevenness L: Light

Claims (5)

A light source that illuminates the yarn,
Light corresponding to the change in the shadow of the yarn irradiated with light, arranged in the direction opposite to the light source with respect to the yarn, and two series of light receiving elements arranged alternately at the same pitch in the running direction of the yarn A differential spatial filter element that outputs current;
A yarn traveling monitoring device including
The yarn is a filament yarn, running the pitch Ri der substantially same as the distance from the distance or convex in recessed from concave irregularities on the surface of the yarn to the convex, the pitch Ru 50~500μm der Monitoring device. The distance from the concave to the concave or the distance from the convex to the convex is an average value of the distances from the concave to the concave of the plurality of irregularities on the surface of the yarn, an average value of the distance from the convex to the convex, or both The travel monitoring apparatus according to claim 1, comprising an average value of distances. Means for converting to a pulse corresponding to the value of the photocurrent of the differential spatial filter element;
Means for determining the presence or absence of running of the yarn based on the presence or absence of the pulse;
The travel monitoring apparatus according to claim 1 or 2, comprising: Means for emitting a signal in response to the operation of the means for running the yarn;
The timing of the pulse generated by the means for emitting the signal and the pulse generated by the photocurrent of the differential spatial filter element are compared, and the yarn travels according to the operation of the means for traveling the yarn. Means for determining whether or not
The travel monitoring apparatus according to claim 3, comprising: The filament yarn is either running monitoring apparatus of claims 1 to 4 comprising a chemical synthetic yarn.

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