JPH0643883B2 - Seam detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seam detection device for detecting a seam of a piece of cloth.

BACKGROUND ART Fabrics are usually manufactured with a length of, for example, 50 m. However, for the treatment after simmering treatment, it is advantageous in terms of processing efficiency to successively process a plurality of fabrics, and May have to be treated individually. For example, brushing treatment,
It is advantageous to perform continuous processing by continuing to fabricate the cloth, such as shearing and steaming.

However, in each of the above processes, it may be inconvenient to process the seam part and the piece of cloth in the same manner as described later.In such a case, when the seam is detected, the seam is detected. Has a method of temporarily suspending the processing and restarting the processing after passing the seam.

FIG. 7 shows an example of a fabric processing device that raises and shears fabric by using such a method. This material processing device feeds a material 1 to be processed, which is composed of a plurality of material continuously spliced with a splicing yarn, along a plurality of guide rolls 2 and drive rolls 3, and a beater roll 5 is provided during a process of moving the material 1.
Is arranged, the brush roll 4 is arranged behind it, the cutter 6 is arranged further behind it, the work material 1 is tapped by the beater roll 5, and then the work material 1 is raised by the brush roll 4. After that, the cutter 6 is used to perform a shearing process, and the shearing process is sent to the next step.

Since the above-mentioned shearing treatment is a treatment for cutting the hairs on the surface of the material to be processed 1 with equal lengths, if the shearing treatment is performed on the joints between the fabrics in the same manner as the fabrics, the yarns of the joints are broken. It is inconvenient that the pieces of cloth are separated from each other, and the sword of the cutter 6 is worn or damaged.

Therefore, the seam detection device 7 is arranged at a position in front of the cutter 6 during the movement process of the workpiece 1, the seam detection device 7 detects the position of the seam between the fabrics, and based on the detection output, the space between the fabrics is detected. The cutter 6 is separated from the workpiece 1 by the automatic cutter elevating / lowering device 8 from the time when the seam reaches just before the position of the cutter 6 to the time when the seam passes by, and the shearing process is not performed at the seam.

Reference numeral 9 is a main drive motor for rotating the drive roll, 10 is a pulse generator for detecting the rotation speed of the drive roll 3, 11 is a motor for driving the brush roll 4, 12 is a motor for driving the beater roll 5, and 13 is a cutter 6. A cutter drive motor 14 to be driven is a control unit that controls the main drive motor 9, motors 11 and 12, cutter drive motor 13, and cutter automatic lifting device 8 based on the outputs of the pulse generator 10 and the seam detection device 7.

The conventional seam detection device used in the above-described fabric processing apparatus is configured so that ultraviolet rays (black light blue discharge lamp) are applied to a workpiece formed by stitching the opposite ends of adjacent fabrics with a fluorescently dyed joint thread. By irradiating and detecting fluorescence (visible light) from the splicing yarn due to ultraviolet rays with an optical sensor, the seam between the fabrics is detected.

When using the method of detecting the fluorescence from such a splicing yarn, only the seam portion of the work piece is optically detected, so that it is irrelevant to the color pattern of the piece of cloth, and because of the reflection and light receiving method, the piece of cloth is Without being restricted by tissue and surface structure,
The advantage is that the seam can be accurately detected.

The seam detecting device will be described below with reference to FIGS. 8 to 13. As shown in FIG. 8, this seam detecting device is configured to splice a plurality of pieces of cloth with fluorescent dyed splicing yarns in a continuous manner in the longitudinal direction and continuously feed the workpiece 21 in the direction of arrow A at 50 Hz or The light from the ultraviolet lamp 22 (arrow B ₁ ) such as a black light blue discharge lamp that lights at 60 Hz is emitted, while the light from the work material 21 (arrow B ₁ ) is emitted.
₂ ) is received by the optical sensor 23, the fluorescence amount signal output from the optical sensor 23 is amplified by the amplifier 24, and then the threshold value circuit 25 compares it with a predetermined threshold value to determine the joint detection signal. It is supposed to occur.

FIG. 9 shows the spectral distribution of each light. The curve C ₁ shows the spectral distribution of the ultraviolet lamp, the curve C ₂ shows the spectral distribution of the fluorescence (visible light) emitted from the joint yarn, and the curve C ₃ shows. The sensitivity distribution of the optical sensor 23 is shown, ν _C1 is the central wavelength of ultraviolet rays, and ν _C2 is the central wavelength of fluorescence.

Now, for example, as shown in FIG. 10, the piece 21a of the workpiece 21 moving in the direction of the arrow A is the ultraviolet lamp 22.
Further, when it is located below the optical sensor 23, the ultraviolet rays from the ultraviolet lamp 22 are only reflected by the cloth article portion 21a and enter the optical sensor 23. On the other hand, as shown in FIG.
When located near the lower side of the optical sensor 23, the ultraviolet rays from the ultraviolet lamp 22 are reflected by the joint 21b and enter the optical sensor 23, and the fluorescence emitted from the joint 21b enters the optical sensor 23.

Considering the joint 21b of the work piece 21 and the piece 21a on both sides of the joint 21b as shown in FIG. 12 (A), the amplifier 2 for amplifying the fluorescence amount signal output from the optical sensor 23 is considered.
The output of No. 4 is, as shown in FIG.
When the cloth material portions 21a on both sides of the are located below the ultraviolet lamp 22 and the optical sensor 23, they are substantially zero. on the other hand,
When the joint 21b is near the lower part of the ultraviolet lamp 22 and the optical sensor 23, a voltage having a waveform similar to the double-wave rectified waveform of the driving power frequency of the ultraviolet lamp 22 (50 Hz or 60 Hz) appears. Therefore, by comparing this voltage with a predetermined threshold value V _TH by the threshold circuit 25, a seam detection signal as shown in FIG. 12 (C) is obtained, and the high level period of this seam detection signal is processed. This corresponds to the seam 21b of the material 21.

Problems to be Solved by the Invention In the seam detection device as described above, the workpiece 21 is irradiated with ultraviolet rays, and the fluorescence emitted from the seam 21b is detected by the optical sensor 23.
Since it is configured to detect the seam 21b by detecting with, the fabric material 21a of the material 21 to be processed may include fluorescent yarn or fluorescent whitening dyed fabric material 21a. Although the level is low, it emits fluorescence similarly to the seam 21b, and there is a possibility that the seam 21b cannot be detected.

Specifically, as shown in FIG. 13 (A), when the workpiece 21 has not only the seam 21b but also the piece 21a having the fluorescence characteristic, the fluorescence amount signal output from the optical sensor 23 is amplified. As shown in FIG. 13 (B), the output of the amplifier 24 is that the joint 21b is the ultraviolet lamp 22 and the optical sensor 2.
In the vicinity of the lower part of 3, a voltage having a waveform similar to the double-wave rectified waveform of the driving power source frequency of the ultraviolet lamp 22 appears. Also, when the cloth parts 21a on both sides of the joint 21b are located below the ultraviolet lamp 22 and the optical sensor 23, the same waveform as the above appears although the level is low. Therefore, when the output voltage of the amplifier 24 is compared with the threshold value V _TH in the threshold circuit 25, the output voltage of the threshold circuit 25 is determined not only by the joint 21b but also by the countersunk portions 21a on both sides depending on the threshold level. Has reached a high level and the seam 21
In some cases, it is not possible to distinguish between b and the piece 21a. In order to distinguish this, the threshold value V _TH may be set appropriately, but the amount of fluorescence of the cloth article portion 21a is different, and it is impossible to set the threshold value applicable to all the cloth articles. .

In response to the above-mentioned problem, generally, an electric filter is used to extract only the changed portion of the output of the amplifier 24. In that case, first, it is necessary to remove the lighting frequency component of the ultraviolet lamp 22 by passing it through a low-pass filter, and the cut-off frequency of the low-pass filter at that time must be about 10 times the normal signal frequency.

However, in the processing of fabrics, the processing speed of fabrics is 10
~ 100 m / min and the length of the joint 21b is 1 cm ~ 2
In the case of cm, the frequency of the signal corresponding to the seam 21b is about 5 Hz to 60 Hz, which is close to the signal frequency and the lighting frequency of the ultraviolet lamp 22 (50 Hz or 60 Hz). It is difficult to separate. Therefore, it was not possible to detect the seam 21b in the piece of cloth having the fluorescent property.

An object of the present invention is to provide a seam detection device capable of surely detecting a seam of a piece of cloth even if it is a piece of cloth having fluorescence characteristics.

Means for Solving Problems A seam detection device of the present invention is a seam detection device for detecting a seam of a work material in which a plurality of pieces of cloth are continuously spliced in a longitudinal direction by a splicing yarn having fluorescence. An ultraviolet lamp for irradiating the material to be processed, which is lit at a high frequency and sent in the longitudinal direction with ultraviolet light, an optical sensor for detecting fluorescence from the material to be processed, and a fluorescence amount signal output from the optical sensor. A low-pass filter for removing a lighting frequency component of the ultraviolet lamp, a high-pass filter for removing a DC component corresponding to fluorescence generated at a substantially constant level from the plurality of pieces of cloth itself from an output signal of the low-pass filter, and the high-pass filter And a threshold circuit that compares the output signal of the device with a threshold value.

Effect According to the configuration of the present invention, by irradiating the material to be processed with the light of the ultraviolet lamp that is turned on at a high frequency, the fluorescence from the seam in the fluorescence amount signal obtained from the material to be processed is incident on the optical sensor at a time. The lighting frequency of the ultraviolet lamp is far away from the corresponding frequency, and the fluorescence amount signal obtained from the work piece is passed through a low-pass filter. Effectively removes the lighting frequency component of the fluorescence amount signal including the frequency component (DC component) corresponding to the fluorescence generated at a substantially constant level from itself, and further passes the output of the low pass filter through the high pass filter A high-pass filter that effectively removes the frequency component corresponding to the fluorescence from itself and only has the frequency component corresponding to the seam. The seam is detected by comparing the output with a threshold value. For this reason, the output of the high-pass filter can be kept the same regardless of the presence or absence of fluorescence from the piece of cloth itself, and if there is a difference in the amount of fluorescence between the seam and the piece of cloth, it can be ensured without changing the threshold value. The seam can be detected, and it is not necessary to change the threshold for detecting the seam depending on the presence or absence of fluorescence from the piece of cloth itself, so the type of cloth of the piece of cloth (fluorescent dyeing and other dyeing) It is possible to detect seams without paying any attention to.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 6. This seam detection device, as shown in FIG.
Work piece 21 in which a plurality of pieces of cloth are spliced continuously in the longitudinal direction with a splicing thread having fluorescent characteristics by fluorescent dyeing or the like.
A seam detecting device 21b for detecting a seam 21b, and an ultraviolet lamp 22 'such as a black light blue discharge lamp for irradiating the material 21 sent in the longitudinal direction with a high frequency and emitting ultraviolet light; An optical sensor 23 for detecting fluorescence from the optical sensor 23, a band filter 26 for removing a lighting frequency component and a DC component of the ultraviolet lamp 22 'in the fluorescence amount signal output from the optical sensor 23, and an output of the band filter 26. And a threshold circuit 25 for comparing In this case, UV lamp 2
The lighting frequency of 2'is 100 times or more the frequency corresponding to the joint 21b of the fluorescence amount signal, and is usually 1 to 3 times.
The frequency is set to about 0 kHz, but in this embodiment, for example, 30 k
It is set to Hz.

The band-pass filter 26 includes a low-pass filter 27 for removing a lighting frequency component of the ultraviolet lamp 22 'included in the fluorescence amount signal, and a DC component (counterpart 21a) included in the fluorescence amount signal.
Is generated by the high-pass filter 28 for removing the fluorescence (at a substantially constant level), and the fluorescence from the joint 21b of the fluorescence amount signal is emitted from the optical sensor 2 as shown in FIG.
For the frequency corresponding to the time of incidence on (3, (1/1
100% pass in the frequency range 0) to 10,
The cutoff frequency of the low pass filter 27 is set to 10 and the cutoff frequency of the high pass filter 28 is set to (1/10). There is.

Next, the operation will be described with reference to FIGS.

First, as shown in FIG. 3 (A), a workpiece 21 (cross-hatching shows strong fluorescence) 21 in which a piece of cloth having no fluorescent property is spliced with a splicing yarn, and a piece of cloth 2 on both sides of the seam 21b.
Considering 1a, the output of the amplifier 24 for amplifying the fluorescence amount signal which is the output of the optical sensor 23 is as shown in FIG.
As shown in FIG. 7, when the joint 21b is near the lower part of the ultraviolet lamp 22 'and the optical sensor 23, the fluorescence from the joint 21b enters the optical sensor 23, and both of the driving power supply frequency (for example, 30 kHz) of the ultraviolet lamp 22' are increased. A voltage having a waveform similar to the wave rectified waveform appears. On the other hand, seam 2
Fluorescence does not occur in the piece 2a on both sides of 1b, and the amplifier 2
The output of 4 is zero.

When the output of the amplifier 24 is passed through the low pass filter 27, the lighting frequency component of the ultraviolet lamp 22 'is removed and the waveform becomes as shown in FIG. 3 (C), and when passed through the high pass filter 28, the direct current component is removed. The waveform becomes as shown in FIG.
By comparing with _TH , a joint detection signal as shown in FIG. 3 (E) can be obtained.

Further, as shown in FIG. 4 (A), a processed material in which a piece of cloth having a weaker fluorescent property than the splicing yarn is spliced with the splicing yarn (cross hatching indicates strong fluorescence, hatching indicates weak fluorescence) 21
Considering the joint 21b and the cloth article 21a on both sides thereof, the amplifier 2 for amplifying the output of the optical sensor 23
As shown in FIG. 4 (B), when the joint 21b is located below the ultraviolet lamp 22 'and the optical sensor 23, the fluorescence from the joint 21b enters the optical sensor 23 and the ultraviolet lamp 22 outputs the output of FIG. 'Drive power frequency (eg 30
A voltage with a waveform similar to the double rectified waveform of (kHz) appears. On the other hand, in the cloth article 21b on both sides of the joint 21b, fluorescence is generated to a lesser extent than in the joint 21b, and the output of the amplifier 24 becomes a value according to the amount of fluorescence from the cloth article 21b.

When the output of the amplifier 24 is passed through the low-pass filter 27, the lighting frequency component of the ultraviolet lamp 22 'is removed and the waveform becomes as shown in FIG. 4C, and when passed through the high-pass filter 28, the direct current component is removed. The waveform shown in FIG. 4 (D) is the same as that shown in FIG. 3 (D). By comparing this waveform with the threshold value V _TH in the threshold circuit 25, FIG.
A seam detection signal as shown in (E) is obtained.

Here, the frequency corresponding to the time when the fluorescence from the joint 21b in the fluorescence amount signal is incident on the optical sensor 23 is 1 for the effective length of the optical sensor 23 and L for the length of the joint 21b.
If the feed speed of the work material 21 is v, Given in. This equation is derived as follows. That is, as shown in FIG. 5, fluorescence from the seam 21b is scattered not only when the seam 21b is directly below the optical sensor 23, but also at positions within the length L of the seam 21b before and after the seam 21b. Will be incident by
The amount of light incident on the optical sensor 23 changes in level as shown in FIG. 6 when the seam 21 b passes below the optical sensor 23. Note that FIG. 6 shows a case where the lighting frequency component of the ultraviolet lamp is not included.

The time T during which the fluorescence from the seam 21b is incident on the optical sensor 23 is Is expressed from this time T It will be.

For example, l = 2 cm, L = 2 cm, v = 18 m / min = 30 cm
/ Second, And l and L are the same as above, and the feed speed v is 9m.
When set in the range of / min to 36 m / min, the frequency becomes = 2.5 Hz to 10 Hz, and in the case of = 10 Hz, the lighting frequency F of the ultraviolet lamp is, for example, 100 times the frequency, F = 10 × 100 = 1000 Hz = 1kHz.

In this embodiment, since the material 21 to be processed is irradiated with ultraviolet rays from the ultraviolet lamp 22 'which is turned on at a high frequency, the ultraviolet lamp 22 has a frequency corresponding to the time when the fluorescence from the seam 21b enters the optical sensor 23 in the fluorescence amount signal. Since the lighting frequency of ′ ′ is sufficiently distant, the lighting frequency component of the ultraviolet lamp 22 ′ included in the fluorescence amount signal output from the optical sensor 23 can be removed, and the DC component is removed, and then the threshold V _TH. By comparing it with the fabric part 21a
Even if the fluorescent material has a fluorescent property, the seam 21b and the piece 2
If there is a difference in the amount of fluorescence from 1a, the seam 21b can be reliably detected without changing the threshold value.

If the sensitivity distribution of the optical sensor 23 partially overlaps with the spectral distribution of ultraviolet rays, a component for removing the ultraviolet rays can be generated by placing a filter for removing the ultraviolet rays in front of the light receiving portion of the optical sensor 23. Does not appear in the output of.

Further, when the portion of the workpiece 21 facing the ultraviolet lamp 22 'and the optical sensor 23 shakes, the shake causes a change in the level of the fluorescence amount signal, which may cause a malfunction. The portion of the material 21 facing the ultraviolet lamp 22 'and the optical sensor 23 is preferably moved on a flat plate-like object to prevent the workpiece 21 from shaking.

In the present invention, a piece of cloth means a piece having a long shape, and its fiber structure and constituent fibers such as woven fabric, knitted fabric and non-woven fabric are not particularly limited.

EFFECTS OF THE INVENTION In the seam detection device of the present invention, by irradiating the work material with the light of the ultraviolet lamp that is turned on at a high frequency, the fluorescence from the seam in the fluorescence amount signal obtained from the work material is incident on the optical sensor. The lighting frequency of the ultraviolet lamp is far away from the frequency corresponding to time, and the fluorescence amount signal obtained from the work piece is passed through a low-pass filter, so that the frequency component and lighting frequency component (high frequency component) corresponding to the seam And effectively remove the lighting frequency component in the fluorescence amount signal including the frequency component (DC component) corresponding to the fluorescence generated at a substantially constant level from the cloth itself, and further pass the output of the low-pass filter through the high-pass filter. Effectively removes the frequency component corresponding to the fluorescence from the piece itself, and only the frequency component corresponding to the seam is high pass. Seams are detected by comparing the output of the filter with a threshold value. Therefore, the output of the high-pass filter can be kept the same regardless of the presence or absence of fluorescence from the piece of cloth itself, and if there is a difference in the amount of fluorescence between the seam and the piece of cloth, it is possible to ensure that the threshold value is not changed. Since it is possible to detect seams and there is no need to change the threshold value for seam detection depending on the presence or absence of fluorescence from the piece itself, it is possible to change the type of piece of cloth (fluorescence staining or other staining) Seams can be detected without any attention

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention,
FIG. 2 is a frequency characteristic diagram of a band-pass filter, FIGS. 3 and 4 are signal waveform diagrams of respective portions in FIG. 1, and FIGS. 5 and 6 are explanations of time when fluorescence from a seam is incident on an optical sensor. FIG. 7, FIG. 7 is a schematic diagram showing the structure of a piece processing device, FIG. 8 is a block diagram showing the structure of a conventional seam detection device, and FIG.
The figure shows the spectral distribution of ultraviolet rays and fluorescence and the sensitivity distribution of the optical sensor, and FIGS. 10 and 11 are schematic diagrams showing the state of light incident on the optical sensor, FIGS. 12 and 13.
The figure is a signal waveform diagram of each part of FIG. 21 ... Workpiece material, 21a ... Fabric part, 21b ... Seam, 2
2 '... UV lamp, 23 ... Optical sensor, 25 ... Threshold circuit, 26 ... Band filter

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masahiro Sawamura 2-87, Muromura-cho, Ogaki-shi, Gifu (56) References JP-A-60-14104 (JP, A) JP-B-45-37200 (JP, B1)

Claims (1)

[Claims] 1. A seam detection device for detecting a seam of a work material, which is formed by continuously connecting a plurality of pieces of fabric with a fluorescent splicing yarn so as to be continuous in the longitudinal direction, and is turned on at high frequency and sent in the longitudinal direction. An ultraviolet lamp for irradiating the material to be processed with ultraviolet rays, an optical sensor for detecting fluorescence from the material to be processed, and a low-pass for removing a lighting frequency component of the ultraviolet lamp in a fluorescence amount signal output from the optical sensor. A filter, a high-pass filter that removes a direct current component corresponding to fluorescence generated at a substantially constant level from the plurality of pieces of cloth itself from the output signal of the low-pass filter, and compares the output signal of the high-pass filter with a threshold value. A seam detection device having a threshold circuit.