JPH0333210A - Detection of yarn breakage and equipment therefor - Google Patents

Abstract

PURPOSE:To sensitively detect yarn breakage by arranging plural light emitting elements on one side of the lower part of a spinneret having many nozzle holes and plural receptors facing thereto across filament yarns and detecting change of the amount of light received due to rounding of the broken end of a yarn. CONSTITUTION:A group of light emitting elements 20 composed of plural light emitting elements (P) and capable of radiating light to a through area of all the filaments extruded through nozzles 17 are arranged on one side of the lower part of a spinneret 10 having many nozzle holes 17 and a group of receptors 21 composed of plural receptors (R) capable of receiving light radiated from the light emitting elements (P) of the group of light emitting elements 20 and partly intercepted by the filaments are arranged facing to the above mentioned group of light emitting elements 20 across the filaments. When yarn breakage occurs, the broken end of a filament is spontaneously formed into a ball-shaped body 18 on the outlet side of the nozzle to intercept more amount of light from the light emitting elements. The reduction of the amount of light received by the receptors (R) due to the above mentioned interception is detected, thus detecting yarn breakage.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a yarn breakage detection method and apparatus capable of sensitively detecting yarn breakage in a spinning device, particularly yarn breakage at the filament stage.

(Prior Art) Various methods and devices for detecting yarn breakage in spinning devices are known, but most of them are non-contact methods using photoelectric yarn breakage detectors (for example, Japanese Patent Laid-Open No. 52 −
88607, JP-A-53-6633).

All of these conventional yarn breakage detection devices detect yarn breakage at a point after a large number of filaments extruded from a spinneret are bundled into yarn.

For example, the presence or absence of yarn breakage near the godet roll or near the take-up roller is detected.

(Problems to be Solved by the Invention) The conventional device described above detects yarn breakage during spinning of organic synthetic fibers. When spinning organic synthetic fibers, the spinning dope has a high viscosity and strength, so filament breakage is difficult to occur near the spinneret, but yarn breakage is likely to occur near the godet rolls where tension is applied. Therefore, it is only necessary to detect a break in the thread that has become thicker due to the filaments converging near the godet roll, and this detection can be performed relatively easily.

However, the viscosity of the spinning dope used for thermal weaving is not very high due to its nature, and the strength of the precursor fiber before firing is weak, so yarn breakage often occurs at the filament stage directly below the spinneret.

Furthermore, even in the case of carbon fiber, thread breakage is likely to occur at the filament stage. When thread breakage occurs like this,
Due to the low clay content of the spinning dope, the spinning dope flows down to the cut end of the filament on the side that protrudes from the spinneret, gradually grows into grains, and eventually falls and adheres to the threads that are bunched downward. have a negative impact.

Therefore, it is necessary to detect thread breakage at an early stage and take necessary actions.

However, since the filament is extremely thin, there is a problem in that optical detection devices cannot easily detect thread breakage.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a yarn breakage detection method and apparatus that can detect yarn breakage at an early stage with high sensitivity at the filament stage. It is in.

(Means for Solving the Problems) In the present invention according to the above-mentioned object, a plurality of light emitting elements are provided on one lower side of a spinneret in which a large number of spinning nozzles are opened. A plurality of light emitting elements capable of emitting light are disposed in a passage area, and are opposed to the light emitting element group with a filament in between to receive light emitted from the light emitting elements of the light emitting element group and partially blocked by the filament. A light-receiving element group consisting of light-receiving elements is arranged, and the filament breaks, and the cut end of the filament on the side protruding from the spinning nozzle becomes granular.
This method is characterized in that a decrease in the amount of light received by the light-receiving element due to the granules blocking more light from the light-emitting element is detected and a thread breakage is determined.

Further, a group of light emitting elements, which is composed of a plurality of light emitting elements, is arranged at one side below a spinneret in which a large number of spinning nozzles are opened, and is capable of irradiating light to a passage area of all the filaments extruded from the spinning nozzles. a light-receiving element group consisting of a plurality of light-receiving elements arranged to face the light-emitting element group with a filament in between and receiving light emitted from the light-emitting elements of the light-emitting element group and partially blocked by the filament; A light reception signal from a single light receiving element or a predetermined plurality of light receiving elements of the element group is input, and this light reception signal is sampled multiple times to calculate the average amount of light received by the light receiving elements as a reference value. a first memory for storing the set value calculated by the calculating means; and a first memory for storing the set value calculated by the calculating means; or a second memory that stores the amount of light received by a plurality of predetermined light receiving elements, a comparison means that compares the contents of the first memory and the second memory, and when compared by the comparison means, The present invention is characterized by comprising a control means that determines that thread breakage has occurred and activates an alarm means when the amount of received light stored in the second memory is smaller than the set value.

Further, it is preferable to arrange one pair of light emitting element groups and one pair of light receiving element groups in the vertical and horizontal directions.

(Function) In the present invention, instead of focusing on the filament itself, when filament breakage occurs, the spinning stock solution flows down to the cut end of the filament on the spinning nozzle side and grows in granules, so we focus on this granular body, By detecting the blockage of light by granules, yarn breakage can now be detected with high sensitivity.

If the light emitting element group and the light receiving element group are arranged both vertically and horizontally,
It is also possible to detect the position of the spinning nozzle where yarn breakage has occurred, and necessary processing for yarn breakage can be carried out at an early stage.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a schematic diagram of the spinning device. IO is a spinneret, which has about 500 spinning nozzles, from each spinning nozzle the spinning dope is extruded in the form of filaments, and these filaments are bundled into a godet roll. 12 and 14, and is wound up as a thread onto a winding roll 16.

In the case of inorganic fibers, a mixture of water, a water-soluble metal compound, and a water-soluble organic polymer is used as the spinning dope composition. This spinning dope is extruded from a spinneret, and an inorganic fiber precursor is obtained by dry spinning. By firing this precursor,
Inorganic fibers can be obtained by decomposing metal compounds and organic polymers.

In the case of carbon fibers, pitch is used as the spinning dope composition.

When obtaining a precursor by extruding the above-mentioned spinning dope for inorganic fibers or carbon fibers, the elastic modulus is lower than that of organic synthetic fibers.
Both strength is low, and as described above, thread breakage tends to occur immediately below the spinneret 10. When such yarn breakage occurs, the cut end of the filament protruding from the spinning nozzle 17 gradually grows into a granular body 18 with a diameter of about 1 to 5 mm, as shown in FIG.

In the present invention, paying attention to the above phenomenon, the state of the filaments directly under the spinneret 10 is optically monitored to detect yarn breakage.

To this end, as shown in FIG. 3, a photoelectric yarn breakage detector is placed on one side of the lower side of the spinneret 10, which can cover the entire filament passage area.

This photoelectric detector includes a light emitting element group 20 in which light emitting elements such as LEDs are arranged in a row, which is arranged on one side of a passage area of all the filaments, and a light emitting element group 20, in which light emitting elements such as LEDs are arranged in a row, and a It consists of a light receiving element group 21 in which light receiving elements such as photodiodes are arranged on the side.

Therefore, when filament breakage occurs, granules 18 with an extremely large diameter compared to the filament grow below the spinning nozzle 17, as shown in FIG. As a result, the amount of light received by the light-receiving element decreases, allowing thread breakage to be detected with high sensitivity.

FIG. 4 shows an example of the arrangement of the light emitting element group 20 and the light receiving element group 21 with respect to the spinneret 10. In this embodiment, the spinning nozzle 17 is arranged concentrically with the spinneret 10.

The light-emitting elements P of the light-emitting element group 20 and the light-receiving elements R of the light-receiving element group 21 are the same in number, 5, and are arranged facing each other. In the illustrated example, 11 each are arranged.

A tube 23 whose inner surface is shielded from light is arranged in front of each light emitting element P, and a lens (not shown) is inserted into the front end of the tube 23 so that the light emitted from the light emitting element P is transmitted from the front end of the tube 23. It is designed to spread and emit within a predetermined angular range. In the illustrated example, light emitted from one light emitting element P is received by three light receiving elements R arranged facing each other. In this way, the light emitting element group 20
The light emitted from the whole is set so as to irradiate the passage range of all the filaments extruded from the spinning nozzle 17, and in the light receiving element group 2, the light emitted from the light emitting element group 20 is set to irradiate all the filaments extruded from the spinning nozzle 17. It is possible to detect when light is blocked by the filament.

In the light-receiving element group 21, an electric signal corresponding to the amount of light received by each light-receiving element R is passed through the light-receiving circuit 24, A/D exchanged, and input to the CPtJ 25.

The CPU 25 performs the following processing according to pre-installed instructions.

First, when a start signal to start spinning is input, the CPU
In 25, at each predetermined time interval, R-1
・2・3, R-2・3・4, R, -3・4・5...
・・R-7・8・9, R-8・9・10, R-9・1O
-11 (the number indicates the order of the light receiving elements),
The total amount of light received is sampled for each of the three light-receiving element groups that are shifted by one, and the reference value for the amount of light received by each of the three light-receiving element groups is set using the average value of the sampled values several times, for example, five times. , store this base ′$ value in memory. This reference value will be a different value for each of the three light-receiving element groups, since the number of filaments that each of the three light-receiving element groups has is usually different. Next, a value obtained by subtracting a predetermined tolerance value from this reference value is set as a set value for the amount of light received for each of the three light receiving element groups, and is stored in the memory.

The setting of the above tolerance value is necessary because the diameter of the filament at the position to be detected usually changes due to fluctuations in the viscosity of the spinning solution, ambient temperature, etc. even during normal operation, so the diameter of the filament increases and blocks light. This is to prevent erroneous judgment that thread breakage has occurred even though no thread breakage has occurred when the amount becomes large.

Note that the diameter of the filament extruded from the spinning nozzle 17 is about 200 μm in the vicinity of the spinning nozzle. Therefore, when viewed from the light emitting element P side, the plurality of filaments do not overlap, and the total width thereof is 1 to 5 mrn of the diameter of the granular body 18.
If there is no significant difference between the two values, it will not be possible to set an effective tolerance value. In this case, the light emitting element group 20 and the light receiving element group 21 are arranged at a position considerably lower than the spinneret 10. In this manner, the diameter of the filament becomes considerably thinner at a position far below the spinneret 10, so there is a significant difference between the total width of the filament and the diameter of the granular material 18, which is 1 to 5 mm.

After setting the set values as described above, when normal operation is started, thread breakage can be detected as follows.

That is, in the CPU 25, each 3
The total amount of light received by each light receiving element group is captured as a signal and stored in the memory, this is compared with the set value in the memory, and when the amount of light received is lower than the set value, it is determined that thread breakage has occurred, For example, an abnormality is reported by controlling an alarm means such as an alarm lamp or a buzzer to be activated.

Note that it goes without saying that the above reference value, and therefore the set value, may be updated each time.

Further, in the above embodiment, the amount of received light is detected for each of three groups of light receiving elements shifted one by one for the following reason.

As shown in FIG. 6, the filament (marked with a black circle) belonging to region A blocks the light emitted from one light emitting element P-4,
This affects the amount of light received by the three light receiving elements R-3, R-4, and R-5. The filament belonging to region B (marked △) is 2
It blocks the light emitted from the two light emitting elements P-3 and P to P4, respectively, and affects the amount of light received by the two light receiving elements R-3 and R-4. Also, the filament belonging to area C (white circle) is 3
The light emitted from each of the light emitting elements P-2, P-3, and P-4 is blocked, thereby affecting the amount of light received by the single light receiving element R-3. Therefore, the total amount that the filament belonging to area A blocks the amount of light received by the three light receiving elements, area B
The total amount by which the filament belonging to region C blocks the amount of light received by two light receiving elements and the amount by which the filament belonging to region C blocks the amount of light received by one light receiving element are approximately the same. Therefore, it is sufficient to consider the filament belonging to region A and detect the total amount of light received for each of the three light receiving element groups. For example, if the amount of light received is detected for each light-receiving element, if thread breakage occurs in area A, the amount of intercepted light received will be distributed to three light-receiving elements, so the amount of intercepted light will change for each area. However, control becomes difficult and yarn breakage in area A becomes difficult to judge.

Therefore, when the light from the light-emitting element P is set to be received by n light-receiving elements R, it is preferable to detect the total amount of light received by each group of n light-receiving elements shifted by one.

In the embodiment shown in FIG. 5, the spinning nozzle 17 of the spinneret 10
are arranged in a grid pattern rather than concentrically. Each pair of light-emitting element P and light-receiving element R is arranged to correspond to each row of the spinning nozzle 17, and the light-receiving element R receives light that is partially blocked by the filaments existing (overlapping) in each row. I try to do that. In this case, each light emitting element P
As the light emitting element, for example, a laser diode that emits coherent light is used so that the light emitted from the light receiving element R is received only by one corresponding light receiving element R.

When the filaments in each row break, granules grow on the tips of the cut filaments in the same manner as described above, so the amount of light received by each light receiving element decreases, making it possible to determine whether the filaments are broken. In this case, the setting value can be set for each can of the light-emitting element and the light-receiving element, so the processing procedure becomes easy.

As another example, the spinning nozzles may be arranged not only in horizontal rows but also in vertical rows (diagonal rows are also acceptable. This diagonal row is also included in the concept of vertical rows).
By arranging a light emitting element and a light receiving element on both sides to detect yarn breakage, it is possible to determine which position of the spinning nozzle 17 of the spinneret 10 the filament is coming from from the yarn breakage information of the horizontal and vertical rows. It is possible to determine whether the thread has broken, and to take immediate action to deal with the thread breakage. In this case, it is convenient if the CPU 25 calculates which spindle and which position of the spinning nozzle the filament has broken, and outputs and displays it on a suitable display device. Note that even if the spinning nozzles are arranged in a staggered manner, detection in vertical and horizontal rows is possible.

The spinning dope is not limited to the above-mentioned inorganic fibers and carbon fibers,
It can be applied to any type of material in which, when the filament is broken, granules are formed at the tip of the cut filament below the spinneret.

The present invention has been variously explained above with reference to preferred embodiments, but the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. That's true.

(Effects of the Invention) In the present invention, we do not focus on the filament itself, but rather on the granules because when the filament breaks, the spinning dope flows down to the cut end of the filament on the spinning nozzle side and grows into granules. However, by detecting the blockage of light by the granules, yarn breakage can now be detected with high sensitivity.

If the light emitting element group and the light receiving element group are arranged both vertically and horizontally,
It is also possible to detect the position of the spinning nozzle where yarn breakage has occurred, and necessary processing for yarn breakage can be carried out at an early stage.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the outline of the spinning device, Fig. 2 is an explanatory diagram showing the state of the granules when the yarn breaks, Fig. 3 is an explanatory diagram showing the arrangement of the light emitting element and the light receiving element, and Fig. 4 is a group of light emitting elements,
FIG. 5 is an explanatory diagram of an example of arrangement of a group of light receiving elements, FIG. 5 is an explanatory diagram of a state in which spinning nozzles are arranged in a grid pattern, and FIG. 6 is an explanatory diagram showing a state in which light from light emitting elements is spread. lO...Spinneret, 1st...Particle, 20 21...Light receiving element group, 25...CPU, p.R...Light receiving element.

Claims (1)

[Scope of Claims] 1. A spinneret having a plurality of spinning nozzles opened on one lower side is composed of a plurality of light emitting elements, and is capable of irradiating light to a passage area of all the filaments extruded from the spinning nozzles. A light-emitting element group is arranged, and a light-receiving element group consisting of a plurality of light-receiving elements is arranged to face the light-emitting element group with a filament in between, and receives light emitted from the light-emitting elements of the light-emitting element group and partially blocked by the filament. When placed, the filament breaks, and the cut end of the filament on the side that protrudes from the spinning nozzle becomes granular.
A yarn breakage detection method characterized by detecting a decrease in the amount of light received by a light receiving element due to the granules blocking more light from a light emitting element and determining that the yarn is broken. 2. A group of light-emitting elements, which are composed of a plurality of light-emitting elements and are arranged at one side below a spinneret in which a large number of spinning nozzles are opened, and can irradiate light to the passage area of all the filaments extruded from the spinning nozzles. and a light-receiving element group consisting of a plurality of light-receiving elements arranged to face the light-emitting element group with a filament in between, and receiving light emitted from the light-emitting elements of the light-emitting element group and partially blocked by the filament; A light reception signal from a single light receiving element or a predetermined plurality of light receiving elements of the element group is input, and this light reception signal is sampled multiple times to calculate the average amount of light received by the light receiving elements as a reference value. a calculation means for calculating a set value by subtracting a predetermined tolerance value from the reference value; a first memory for storing the set value calculated by the calculation means; and a single memory of the light receiving element group. or a second memory that stores the amount of light received by a plurality of predetermined light receiving elements, a comparison means that compares the contents of the first memory and the second memory, and when compared by the comparison means, A thread breakage detection device characterized by comprising: control means that determines that thread breakage has occurred and activates an alarm means when the amount of received light stored in the second memory is smaller than the set value. 3. The spinning nozzles of the spinneret are arranged in a grid or staggered pattern, and the light-emitting element group and the light-receiving element group are arranged in pairs on each side of the spinning nozzle in the vertical and row directions, and The corresponding light-emitting elements and light-receiving elements of the element group and the light-receiving element group are arranged corresponding to each vertical and horizontal row of the spinning nozzle, and furthermore, the light-emitting element can irradiate light only to the corresponding filament row, 3. The control means includes a control means for operating a display means for displaying the position of the spinning nozzle where the yarn breakage has occurred based on information about the yarn breakage rows in the column direction and the yarn breakage rows in the row direction. Thread breakage detection device.