JPH03269157A - Yarn-breakage sensor for tufting machine, etc. - Google Patents

Abstract

PURPOSE:To surely detect the yarn breakage by placing a yarn breakage detection light-sensor between a yarn roll and a needle and fixing the position of the yarn with a guiding member at a position to detect the yarn with the light- sensor. CONSTITUTION:Each yarn 8 is pressed with a guiding member 18 between a needle 6 and yarn rolls 10, 12 and the yarn breakage is detected by a light- sensor 28 while guiding each yarn along the guiding groove of the guiding member. The yarn breakage can be surely detected even if the distance between needles is varied.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a thread breakage sensing device for detecting breakage of pile threads during tufting in a tufting machine that forms piles on a base fabric. be.

(Prior Art) A tufting machine has several hundred or more needles5, usually more than 1.000 needles. A thread is threaded through each needle, and a pile is formed on the base fabric with a corresponding number of loopers. When forming a pile, if a thread breaks in one of the needles, the machine must be stopped immediately and repaired, otherwise the product will be defective. Conventionally, a supervisor was placed in front of each machine to check for thread breaks. Although constant monitoring is performed, tufting machines have a large number of needles, so it is often too late to notice thread breakage, and repairs may not be possible.

Therefore, various types of thread breakage sensing devices have been proposed to automatically detect thread breakage. For example, an optical method that detects the presence or absence of thread by irradiating each thread with light is a method that uses laser light and detects thread breakage by reflected light (see Japanese Patent Laid-Open No. 60-34662). 1) The present inventors have proposed that a light sensor is provided in that part which also serves as a presser foot, and the presence or absence of thread is monitored by whether or not light from a light source is incident on the light sensor when the needle is at the top. There is a method. All of these methods optically detect the presence or absence of yarn between the needle and the base fabric.

(Problem to be Solved by the Invention) In the method of optically detecting the presence or absence of thread between the needle and the base fabric when the needle is pulled up to the top, the thread is in a state of tension between the base fabric and the needle. However, there is a problem that the distance between the needles varies, the position of the thread fluctuates, and thread breakage detection becomes uncertain.

An object of the present invention is to provide a thread breakage sensing device that can reliably detect thread breakage even if there is variation in the distance between needles, in a device that detects thread breakage by irradiating light onto multiple threads. This is the purpose.

(Means for Solving the Problems) The present invention includes a guide member that has a groove for guiding the multi-filament between a yarn roll of a tufting machine or the like and a needle, and also pushes the thread from one side to apply tension to the thread. The optical sensor includes a reflective optical sensor for each multi-strand yarn that irradiates light to the yarn guided in the groove of the guide member and receives reflected light from the yarn guided in the groove. Thread breakage is detected by the received light signal.

(Function) Between the yarn roll and the needle, the polyfilament is pushed by a guide member and tension is applied, and the polyfilament is guided along each guide groove of the guide member and passes through a fixed position. . Even if the distance between the needles varies, the position of the thread passing through the groove of the guide member is fixed, and when light is irradiated from each optical sensor to each thread and the reflected light is received, Since the position of the thread is stable, reliable detection can be performed.

When a thread breakage occurs, for example, if the thread breaks at the needle portion, the tension acting on the thread in the groove of the guide member disappears, and the thread separates from the predetermined position in the groove of the guide member. Therefore, a change occurs in the detection signal used by the optical sensor to detect the reflected light from the yarn at a certain position in the groove of the guide member, and the yarn breakage is detected by the output of the optical sensor. The tufting machine may be stopped or an alarm may be issued based on a signal from an optical sensor that detects thread breakage.

(Embodiment) FIG. 1 shows an embodiment in which the present invention is applied to a tufting machine for forming loop piles.

Reference numeral 2 denotes a tufting body, which drives the needle par 4 to move in the vertical direction. A needle 6 is attached to the needle par 4. Several hundred or more needles 6, usually more than ten or more needles 6, are arranged and attached in a direction perpendicular to the plane of the paper as shown in the figure.

Reference numeral 24 denotes a base fabric, and as it moves to the right as shown by the arrow in Figure 1, a pile of yarn 8 is formed by the needle 6 and the looper (not shown). Yarn 8 is yarn roll 1
0.12, and are arranged at regular intervals by the yarn guide 14 in the direction perpendicular to the plane of the paper.

The yarn guide 14 is attached to the tufting body 2 and has holes for guiding the yarn 8 arranged at equal intervals.

16 is a puller roller, which applies internal tension to the yarn.

Reference numeral 20 denotes a jaguar, and 22 denotes a second needle yarn guide. The jaguar 20 is attached to the main body 2, and the needle yarn guide 22 is attached to the needle par 4. thread 8
is guided by a jaguar 20 and a needle yarn guide 22 to the needle 6.

A guide member 1 is provided between the puller roller 16 and the jaguar 20.
8 is provided. The guide member 18 has a groove for guiding the multi-filament 8 and pushes the thread 8 away from the tufting body 2 to apply tension to the thread 8. Guide member 18
A reflective optical sensor 28 is provided to detect breakage of the multi-thread 8.

FIG. 2 shows an example of the guide member 18 and the optical sensor 28 for detecting thread breakage. (A) is a top view of the guide member 18, (B) is (
A) is a front view, and (C) is a cross-sectional view taken along the line CC in (A).

The guide member 18 is made of steel and has a guide groove 26 extending in a direction perpendicular to the paper plane in FIG. 2(A) for guiding the thread 8.
The thread 8 is guided by each guide groove 26 to the jacquard 20.
be guided in a direction. The number of guide grooves 26 is equal to the number of threads required, for example, 2048 threads. Guide groove 2
A window is provided in the center of the thread 6 for irradiating light from the optical sensor onto the thread 8 and allowing reflected light from the thread 8 to enter the optical sensor.

As shown in (C), the guide member 18 includes an optical sensor 28a that irradiates light onto the thread 8 from the guide member side and receives reflected light from the thread 8 on the guide member 18 side.

28b are arranged and attached in the direction perpendicular to the plane of the paper (C). The optical sensors 28a and 28b are 1. For example, if the optical sensor 28a detects the yarn breakage of the odd-numbered yarn 8, the optical sensor 28b is an optical sensor that senses the yarn breakage of the even-numbered yarn 8, and the guide groove Since the spacing between the optical sensors 26 is narrow, it is difficult to arrange the optical sensors 28a and 28b in a single row, so they are alternately arranged in different rows for even and odd numbers. A transparent glass plate 27 is fitted between the optical sensors 28a, 28b and the windows of the guide groove 26 so that the thread 8 does not come into direct contact with the optical sensors 28a, 28b. Each optical sensor 28a, 28b includes a light emitting element such as an LED that irradiates light to the thread 8 passing through the guide groove 26 under tension, and a light receiving element such as a photodiode that receives reflected light from the thread 8. Each is equipped with

The guide member 18 and the optical sensors 28a, 28b are attached to the support 30.
It is attached to the tufting body 2 via.

FIG. 3 shows a circuit that detects thread breakage using one optical sensor 28.

Light is irradiated from the LED 32, which is a light emitting element of the optical sensor 28, to the thread 8 guided by the groove of the guide member, and the reflected light from the thread 8 enters a photodiode 34, which is a light receiving element of the optical sensor 28. detected. Since there are as many optical sensors 28 as there are guide grooves, it is not possible to detect all the detection signals from the optical sensors 28 at the same time.
In order to divide the optical sensor 28 into several blocks and operate them at different times, a decoder 3 for optical sensor selection is provided.
6 is provided. The LED 32 of the optical sensor 28 selected by the decoder 36 emits light.

The detection signal of the photodiode 34 is amplified by the amplifier 38 and inputted to the comparator 40. The comparator 40 compares it with the threshold value vth, and depending on whether the detection signal is larger than the threshold value, the yarn 8 is correctly placed in the guide groove. A reading circuit 42 reads whether or not the guide is in a tensioned state.

When thread breakage occurs, the thread 8 is in a state where there is no tension.
Even if the LED 32 emits light as it moves away from the guide groove of the guide member, the intensity of the reflected light from the thread 8 that enters the photodiode 34 becomes weaker, and the detection signal reaches the threshold v at the comparator 40.
th, and the reading circuit 42 detects thread breakage.

A data processing system that detects thread breakage and the location of the thread breakage using detection signals from a large number of optical sensors 28 will be explained with reference to FIGS. 4 to 8.

For example, 2048 needles are provided.

Correspondingly, it is assumed that 2048 optical sensors are provided in the guide member. If one CPU were to detect the detection signals of such a large number of optical sensors, it would be difficult to process the detection signals of all the optical sensors during one cycle of vertical movement of the needle. Therefore, 2048
As shown in FIG. 4, the detection signals of the 1st to 512th optical sensors are processed by the sub CPU 46-1,
The detection signals of the 3rd to 1022nd optical sensors are processed by the sub CPU 46-2, and the detection signals of the 1023rd to 1536th optical sensors are processed by the sub CPU 46-2.
46-3, and 204th from 1537th
The detection signals of up to the 8th optical sensor are sent to the sub CPU46-4.
4 sub CPUs 46-1 to 46-
4 will be provided. Each sub CPU 46-1 to 46-4
To do this, a rotation detection signal is received from a sensor that detects the rotation of the rotation opening system that instantly moves the needle up and down within the tufting body 2, and all optical sensors are activated during one cycle of the needle's up and down movement using the rotation detection signal as a trigger. The detection signal is processed. Each of the sub-CPUs 46-1 to 46-4 operates simultaneously, and if a thread breakage is detected, the sub-CPU notifies the main CPU 48 of the thread breakage together with the address of the thread that has broken. When the main CPU 48 receives the yarn breakage detection signal, it displays the number of the yarn in which the yarn breakage occurred on the display 50, issues an alarm via the relay 52, and stops the operation of the tufting body 2. The relays 52 include eight relays for indicating the location of thread breakage and one relay for stopping the tufting body.

There are 512 optical sensors processed by each sub CPU 46-1 to 46-4. Figure 5 shows one sub CPU4.
6 and thread breakage is detected by its sub CPU 46 5
A method of processing 12 optical sensors 28-1 to 28-512 will be shown.

The optical sensors are divided into eight blocks each, and a decoder 36 for sensor selection selects the L of the four optical sensors.
The EDs, and therefore 32 LEDs, are simultaneously selected and emitted. The decoder 36 has sub-CPUs 46 to 4.
Bit select data is sent, and the decoder 36
Sixteen blocks each containing an individual optical sensor are sequentially switched and selected during one cycle of vertical movement of the needle. The detection signals of the 32 simultaneously selected optical sensors are
Four reading circuit blocks 42-1 in units of eight optical sensors
42-4 are read by the read decoder 44 as they are selected, and are taken into the sub CPU 4G as thread breakage information.

FIG. 6 shows FIG. 5 in more detail.

There are 512 optical sensors 28 included, and they are arranged in a line from the 1st to the 512th, but in the figure they are shown arranged in a matrix for illustrative purposes.

Selection data SA to SD are supplied to a decoder 36 that selects the optical sensor 28, and 32 optical sensors are simultaneously selected by the selection signal from the decoder 36. 54 is an LED of the optical sensor 28 according to a selection signal from the decoder 36.
This is an amplifier that emits light. 16 optical sensors 28 each
One photosensor 28 is selected from each globe including the one, and the detection signal of one selected photosensor 28 is held in the latches 58-1 to 58-4 via the amplification/comparison circuit 56.

Amplifier and comparator circuit 56 includes amplifiers and comparators as shown later in FIGS. 7 and 8.

Data latch signals DCK are applied to the launches 58-1 to 58-4 from the sub CPU to perform a latch operation, and data read signals SD1 to SD4 cause the latches 58-1 to 58-4 to latch.
Data Do-D7 are sequentially read from No. 4 to Sub CPU. When the reading of the latches 58-1 to 58-4 is completed, the selection signal from the sensor selection decoder 36 is switched to select the next 32 optical sensors 28, and the reading is repeated in the same manner.

A decoder 36 detects all 16 blocks of optical sensors 28.
The movement that is selected and read is one of the up and down movement of the needle.
Finish during the cycle.

FIG. 7 shows a reading circuit for the 16 optical sensors 28 included in a group in one row in FIG.

The optical sensors 28 are, for example, 16 optical sensors from 1st to 16th. One of each optical sensor 28 is selected by a selection signal from a sensor selection decoder 36, and the LED of the selected optical sensor 28 is is the amplifier 54
emits light through.

SE is a power supply signal that causes the LED to energize and emit light.

When there is no yarn breakage in the yarn detected by the selected optical sensor 28, the reflected light from the yarn enters the photodiode of the sensor 28, and the photodiode outputs a high-level detection signal. It enters an amplifier 62. On the other hand, when the thread detected by the selected optical sensor 28 is broken, the thread is not in close contact with the groove of the guide member, and the intensity of the reflected light incident on the photodiode becomes weak, causing the output of the photodiode to decrease. The voltage becomes low level. The output signal VL of the amplifier 62 becomes a low level if thread breakage occurs, and becomes a high level if it is normal.

FIG. 8 shows a part of FIG. 6 in more detail.

The detection signal of the optical sensor selected by the sensor selection decoder is amplified by the amplifier 62 shown in FIG. It is captured. An amplifier circuit 6 is connected to the non-inverting input terminal of each comparator 64.
A threshold voltage is applied through 6. The amplification/comparison circuit 56 in FIG. 6 includes the amplifier 62 in FIG. 7, the comparator 64 in FIG. 8, and the threshold voltage amplifier 66. A latch 59 temporarily holds the power supply signal SE and select data 5A-5D. Signal SAD
is a select switching signal, and select data 5A-3
The optical sensors are sequentially activated via D.

In FIG. 8, eight blocks of output signals from the comparator 64 are captured and held in latches 58-1 to 58-4 at the timing of the clock signal DCK. If there is a thread breakage, the corresponding output signal VL from the optical sensor becomes low level, and the threshold value vth is set so that the low level is lower than the threshold value vth.
Therefore, the output signal of the comparator 64 becomes high level when the thread breaks, and becomes low level when the thread does not break. Data D held in latches 58-1 to 58-4
O to D7 are data read signals S D ].

~SD4 are sequentially switched and taken into the sub CPU in order. The sub CPU detects the presence or absence of a high level signal,
If there is a high level signal, it is detected that the thread at the address where the signal is located is broken.

The yarn breakage sensing operation of the sub CPU will be explained with reference to FIGS. 9 to 11.

FIG. 9 is a flowchart of the initial setting of the sub-CPU. When a rotation detection signal of the rotation system for opening the needle is input, the optical sensor signal is read using the signal as a trigger. Since threads are not necessarily present in all guide grooves and only some guide grooves may be used, locations where there is no optical sensor signal, that is, addresses where the data taken into the sub CPU is at a high level, are Since these addresses have no yarn from the beginning, these addresses are recorded in the skip area as skip signals.

FIG. 10 is a flowchart of the actual yarn breakage sensing operation by the sub CP tJ.

When the rotation detection signal of the rotation/opening system is input, the optical sensor signal is read and compared with the skip signal, and a detection signal indicating that there is no thread at the address where the thread should originally exist is taken into the sub CPU. If there is a high-level signal in the data, it is assumed that a thread breakage has occurred, and a message indicating that there is a thread breakage and the address of the thread breakage are sent as data to the main CPU.

If there is no thread breakage, the thread breakage sensing operation is repeated every time there is a rotation detection signal.

FIG. 11 is a flowchart of the optical sensor signal reading operation in FIGS. 9 and 10.

When the 32 photosensor signals are read, 1 is added to the sensor selection data, the next 32 photosensors are selected by the sensor selection decoder, and the detection signals of those 32 photosensors are read. This operation is repeated until the sensor select data reaches 16.

Until the sensor select data changes from 1 to 16, detection signals from 512 optical sensors are read.

FIG. 12 shows the operation of the main CPU.

Data is input sequentially from the four sub-CPUs, and if there is data indicating thread breakage among the data.

The number of needles at which the thread breakage occurred is read from the data from the sub-CPU, the thread breakage number is displayed on the display, and a relay is activated to issue an alarm and the operation of the tufting body is stopped.

In the example, the number of needles is 2048, and the CPU adopts an NM structure consisting of a sub CPU and a main CPU, but if the number of needles is small, it is also possible to detect thread breakage with one CPU. . The method of performing detection by dividing a large number of optical sensors into a plurality of blocks is not limited to that of the embodiment, and can be modified as appropriate.

(Effects of the Invention) In the present invention, an optical sensor that detects yarn breakage is installed between the yarn roll and the needle, and a guide member is provided at the position where the yarn is detected by the tip sensor to fix the yarn position. It is possible to reliably detect yarn breakage in a tufting machine or the like, and to realize a compact and highly practical yarn breakage detection device.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment, and FIG. 2 is a diagram showing a guide member and an optical sensor in the same embodiment.
is a top view of the guide member, (B) is its left side view, (C) is a sectional view taken along line C-C in (A), and Figure 3 is a circuit diagram showing the detection system of one optical sensor. , Fig. 4 is a block diagram showing the hierarchical structure of the entire CPU, Fig. 5 is a block diagram showing the detection system for one sub-CPU, and Fig. 6 is a block diagram showing the detection system for one sub-CPU.
FIG. 7 is a block diagram showing a photosensor related to the PU and its detection system; FIG. 7 is a circuit diagram showing a set of 16 photosensors that are sequentially selected, a decoder that selects them, and an amplifier for the detection signal; FIG. is a circuit diagram showing a detection system for detecting yarn breakage from the detection signal of the optical sensor; FIGS. 9, 10, and 11 are flowcharts showing the operation of the sub CPU; and FIG. 12 shows the operation of the main CPU. It is a flowchart figure. 2...Tufting body, 6...Needle,
8... Thread, 10.12... Yarn roll, 14... Yarn guide, 16...
Puller roller, 18...Guide member, 20...
...Jaguar, 28...Light sensor, 26...
...Guide groove, 32...LED, 34...
・Photodiode, 36... Decoder for sensor selection, 44... Decoder for data reading, 46° 46-1 to 46-4... Sub CPU,
48...Main CPU, 50...Display, 52...Relay, 58-1 to 58-4
...Latch, 64...Comparator.

Claims (1)

[Claims] (1) A guide member that has a groove for guiding each yarn and applies tension to the yarn by pushing the yarn from one side between the yarn roll of a tufting machine and the needle, and a state where the yarn is guided by the groove of this guide member. The yarn is equipped with a reflective optical sensor for each yarn that irradiates the yarn with light and receives reflected light from the yarn guided in the groove, and detects yarn breakage based on the light reception signal of this optical sensor. Break detection device.