JPH067007U - Unevenness defect detection device for fabric - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a concave-convex defect detecting device for a sheet-shaped fiber woven fabric, which can easily detect the concave-convex defect of the sheet-shaped fiber woven fabric without using optical means. An unevenness detecting means is provided which is provided with a vibration detector that outputs an electrical signal in response to a change in pressure or mechanical vibration, and the vibration detector is arranged so as to come into contact with a sheet-shaped fiber fabric, and the sheet-like shape. Moving means for relatively moving the fiber woven fabric and the unevenness detecting means, and unevenness defect determining means for comparing and determining a predetermined reference level corresponding to the unevenness defect of the sheet-like fiber woven fabric and the output level of the unevenness detecting means. An apparatus for detecting irregularities in a sheet-shaped fiber woven fabric, including:

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an apparatus for detecting unevenness of a sheet-shaped fiber fabric, and in particular, a vibration detector that converts a change in pressure or mechanical vibration into an electrical signal is moved relative to the sheet-shaped fiber fabric in a contact state to compare and determine output signals. The present invention relates to a device for detecting uneven defects of the woven fabric.

[0002]

[Prior art]

 Uneven defects in sheet-like fiber fabric, that is, knots, pills, and weaving bars, are factors that impair the appearance and feel, and their detection is an important issue.

Conventionally, the detection of the unevenness defect of the sheet-shaped fiber woven fabric or the band-shaped body has been performed visually and by touch in the inspection process, but there is a problem that an inspection error such as an oversight occurs. For example, in the texture inspection when several fiber fabrics such as seat belts were inspected at the same time, only partial extraction (extraction) inspection was possible, and it was impossible to accurately detect irregularities.

As a conventional technique for automatically detecting uneven defects, for example, Japanese Patent Application Laid-Open No. 52-760555 discloses a device for detecting the defects using a differential transformer or the like. This device is provided with a member that abuts against the surface of a running belt and responds to it, and converts the displacement of the responding member into an electric signal level to detect irregularities such as seams.

However, this device is provided with a roller that responds to the surface of the belt-like member, and the displacement of the roller is detected by a differential transformer or the like. Therefore, detection of irregularities such as a seam large enough to displace the roller is the limit. .

Further, in recent years, there have been disclosed some devices that irradiate a fiber fabric with laser light, receive the transmitted light or the reflected light, and detect the irregularity defect from the change in the amount of received light.

However, these methods have a problem that a woven pattern affects a textile fabric having a large seam. There are also problems such as the effect of ambient light, dirt on the optical lens due to dust in the factory atmosphere, and the system being large and expensive.

Other devices using image processing have been disclosed. However, these devices have the same problems as the above-mentioned laser light detecting device, and thus it is possible to accurately detect uneven defects at low cost. could not.

[0009]

[Problems to be solved by the device]

 An object of the present invention is to solve the problems of the conventional uneven defect detection device and to provide an uneven defect detection device for a sheet fiber fabric that can easily detect an uneven defect in a sheet fiber fabric at a low cost. I am trying.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention, as shown in FIG. 1, comprises a vibration detector that outputs an electrical signal corresponding to a change in mechanical vibration or pressure, and the vibration detector is a sheet-like fiber fabric. The unevenness detecting means I arranged so as to come into contact with the surface, the moving means for relatively moving the sheet-like fiber woven fabric and the unevenness detecting means I, and a predetermined reference level corresponding to the uneven defect of the sheet-like fiber woven fabric are provided. An unevenness defect detecting device for a sheet-shaped fiber woven fabric, comprising: an unevenness defect determining means II for comparing and determining the output signal level of the unevenness detecting means I.

[0011]

[Action]

 Next, the operation of the present invention will be described with reference to FIG. The unevenness detecting means I is equipped with a vibration detector that outputs an electrical signal when pressure or vibration is applied from the object to be measured, and the vibration detector is arranged so as to come into contact with the sheet fiber fabric. There is.

When either one of the sheet-like fiber woven fabric or the unevenness detecting means or the sheet-like fiber woven fabric and the unevenness detecting means is moved by a moving means (not shown), that is, the sheet-like fiber woven fabric and the unevenness detecting means are relative to each other. When moved to, the vibration detector outputs a signal as shown in FIG.

Note that FIG. 2 shows a signal waveform when the irregular sheet defect comes into contact with the vibration detector and relatively moves from the state where the normal sheet-shaped fiber woven fabric surface comes into contact with the vibration detector and relatively moves. . As shown in FIG. 2, the shapes of the signal waveforms are different between the sections T1 and T3 in which the normal sheet-shaped fiber woven surface is in contact with the vibration detector and relatively moving, and the section T2 in which the irregular defect occurs. .

When an uneven defect is detected from the signal shown in FIG. 2, as can be understood from the figure, the resonance frequency of the vibration detector caused by the relative movement of the sheet-shaped fiber woven fabric and the vibration detector in contact with each other. Since the component signal S1 is detected as a waveform superimposed on the woven pattern component signal S2 due to the woven pattern of the sheet-shaped fiber woven fabric, the S / N ratio of the signal waveform is poor. (This is the case of the ultrasonic sensor, and the resonance frequency component signal S1 is not detected in the case of a normal vibration detector.)

Therefore, in the present invention, the contact movement noise generated when the sheet-like fiber woven fabric composed of the resonance frequency component signal S1 and the weave pattern component signal S2 shown in FIG. A filter for doing so is provided in the unevenness detecting means, and as shown in FIG. 3, the signal component unique to the unevenness defect is clearly extracted.

As can be seen from FIGS. 2 and 3, the present invention eliminates the contact movement noise component generated when the sheet-shaped fiber woven fabric and the vibration detector make relative contact with each other, and the sheet-shaped fiber woven fabric vibrates. It was proposed focusing on the fact that uneven defects can be detected by extracting the signal corresponding to the change in the contact state given to the detector.

That is, when the unevenness defect is brought into contact with the vibration detector and relatively moves, the unevenness defect slides on the surface of the vibration detector, and thus a contact pressure different from that of the normal sheet-shaped fiber woven surface is applied. Further, since the contact movement noise when the surface of the sheet-shaped fiber woven fabric and the vibration detector move relative to each other is composed of a frequency component higher than the signal corresponding to the irregularity defect, the contact movement noise is detected from the output signal of the vibration detector. It is possible to separate the noise component and extract only the contact pressure signal corresponding to the uneven defect, and it is possible to identify the uneven defect.

The irregularity defect determining means II of the present invention determines the irregularity defect by comparing a signal output from the irregularity detecting means I with a predetermined reference level corresponding to the irregularity defect of the sheet-shaped fiber fabric.

As described above, according to the present invention, since the change of the contact pressure due to the irregularity defect is detected by using the vibration detector without using the optical means, the influence of the ambient light, dust, etc. can be avoided. The uneven defect can be easily detected.

Further, according to the present invention, since the uneven defect is detected as a low-frequency signal due to the change of the contact pressure, the uneven defect can be detected stably without being affected by noise such as factory noise.

[0021]

[Preferred Embodiment]

 Further, a preferred embodiment of the present invention other than the above will be described with reference to FIG.

According to a second preferred embodiment of the present invention, the irregularity defect determining means II compares the signal output from the irregularity detection means I with a plurality of predetermined reference levels to determine the irregularity defect. The unevenness defect determining means III is provided for discriminating the level in stages corresponding to each reference level.

According to this embodiment, since the uneven defect is discriminated stepwise according to its size, the occurrence frequency according to the size of the uneven defect can be detected.

In a third preferred embodiment of the present invention, the unevenness defect determining means II compares the signal output from the unevenness detection means I with a plurality of predetermined reference levels, and the unevenness defect is large. And a display control means IV for displaying the occurrence of the irregularity defect based on the output of the irregularity defect determination means III and for controlling the operation of the loom and the like. It is a thing.

According to the present embodiment, the occurrence of the unevenness defect is displayed based on the size of the unevenness defect which is determined in a stepwise manner by the unevenness defect determining means III, and the loom is responsive to the size and the occurrence frequency of the unevenness defect. It is possible to control driving. In addition, it is possible to notify the operator of the size of the unevenness defect that has occurred, and it is also possible to control the loom etc. to be temporarily stopped when the occurrence frequency and size of the detected unevenness defect exceeds a certain amount. It is possible to prevent overlooking of convex defects and improve work efficiency.

According to a fourth preferred embodiment of the present invention, the unevenness detecting means I includes an amplifier for amplifying a signal output from the vibration detector, and a contact pressure due to unevenness defect in the signal output from the amplifier. And a bandpass filter that passes only the signal component due to the change of.

According to the present embodiment, the band-pass filter removes the contact noise caused by the contact movement between the sheet-shaped fiber woven fabric detected by the vibration detector and the vibration detector, so that the S / N ratio of the uneven defect signal is increased. Can be improved.

In a fifth preferred embodiment of the present invention, a holder is provided on the unevenness detecting means I, and a vibration detector is fixed to the holder via a vibration-proof rubber.

In the present invention, it is preferable that the vibration detector has a surface shielded by a smooth member having excellent wear resistance. Also, a member having excellent wear resistance such as smooth thin ceramics can be adhered to the surface for use.

A sixth preferred embodiment of the present invention is an amplifier for amplifying the signal output from the vibration detector in the above-mentioned fourth and fifth embodiments of the present invention, and a signal output from the amplifier. Among them, a bandpass filter that passes only the signal component due to the contact pressure change due to the uneven defect is provided, and this amplifier and bandpass filter are housed in a holder and fixed in close proximity to the output side of the vibration detector.

According to the fifth embodiment of the present invention, since the vibration detector is fixed to the holder via the vibration isolating rubber, mechanical noise transmitted to the vibration detector can be reduced. With the configurations shown in the fifth and sixth embodiments, the S / N ratio of the uneven defect signal can be further improved.

A seventh preferred embodiment of the present invention is a sensor guide for moving the unevenness detecting means I in the longitudinal direction and the width direction of the sheet-shaped fiber woven fabric and in the direction orthogonal to the surface of the sheet-shaped fiber woven fabric. A device is provided.

According to the seventh embodiment, the contact state between the surface of the sheet-shaped fiber woven fabric and the surface of the vibration detector can be arbitrarily set by moving the unevenness detecting means I by the sensor guide device. It is possible to obtain the contact state according to. In the present invention, it is preferable to bring the surface of the sheet-shaped fiber fabric and the surface of the vibration detector into contact with each other with a slight touch.

Further, according to the seventh embodiment, the unevenness detecting means I can be moved and scanned by the sensor guide device in the longitudinal direction of the sheet-like fiber woven fabric and in the width direction orthogonal to the longitudinal direction. By using one vibration detector, it is possible to easily detect uneven defects on the surface of the sheet-shaped fiber fabric having a certain width.

An eighth preferred embodiment of the present invention is further provided with a vibration suppressing means V for suppressing the vibration of the woven fabric by a woven fabric guide device which comes into contact with the sheet-like fiber woven fabric with a constant tension. .

According to the eighth embodiment, it is possible to suppress the swing of the sheet-shaped fiber woven fabric, so that stable contact running between the vibration detector of the unevenness detection means I and the sheet-shaped fiber woven fabric is ensured. To be done.

[0037]

First Embodiment A first embodiment of the present invention will be described in detail below. The unevenness defect detection device according to the first embodiment is applied to the detection of unevenness defects on the surface of an automobile seat belt, which is one of sheet-like fiber fabrics.

As shown in FIG. 4, the concave-convex defect detection device is composed of vibration detectors I 11 and I 12 each having a thin SUS 304 (stainless steel) plate fixed to the surface with a thickness of 0.5 mm, and vibration detection devices I 11 and I 12. The vibration detector rubber I 21, I 22 and the amplification circuits I 31, I 32 for amplifying the output of each vibration detector and the band pass circuits I 41, I 42 connected to each amplification circuit. The vibration detector holders I 51 and I 52, which are built in close to each vibration detector, and the vibration detector holders are moved in the longitudinal direction of the seat belt and in the direction orthogonal to the longitudinal direction, that is, forward, backward, left, and right. The concave-convex detecting means I including the sensor guide devices I 61 and I 62 for performing the operation is provided.

Further, the unevenness defect detection device is provided with an unevenness defect determination means III composed of determination circuits III 11 and III 12 connected to each band pass circuit of the unevenness detection means I, and an unevenness by an output from each determination circuit. It is provided with a concave-convex defect discriminating means II constituted by a display control means IV for displaying the occurrence of defects and controlling the operation of the loom and the like.

Further, the unevenness detecting apparatus of the present embodiment swings the seat belt a by the guide rollers V11 and V12 arranged so that the rotation axes for contacting and guiding the seat belt a with a constant tension are parallel to each other. A swing control means V for suppressing movement is provided.

As each vibration detector of the unevenness detection means I, one that can obtain an output signal based on the difference in contact pressure between the unevenness defect and the normal seat belt surface, that is, the vibration or pressure is an electrical signal. Any material such as a piezoelectric material that can be converted into an ultrasonic sensor, such as an ultrasonic sensor, an AE sensor, or an acceleration sensor can be used.

Although a semiconductor gauge can be used, it is necessary to perform instrumentation so that the surface that comes into contact with the seat belt, such as the ultrasonic sensor, becomes smooth.

In this embodiment, an ultrasonic sensor, which is an ultrasonic wave receiver having a relatively large surface and a low price, is used. Ultrasonic sensors generally have a center frequency in a high frequency band outside the audible sound band, but when a shock change such as pressure is applied to the surface, a low frequency signal of several Hz is output, so In the embodiment, this low frequency signal is detected.

The vibration detectors I 11, I 12 are brought into contact with the surface of the seat belt a by adjusting the positions of the vibration detector holders I 51, I 52 by the sensor guide devices I 61, I 62, respectively. Will be placed. As the vibration detectors I 11 and I 12 are pressed against the surface of the seat belt a, the detection sensitivity of the unevenness defect is improved, but when the vibration detectors and the seat belt a are moved relative to each other while they are in contact with each other, the seat belt a Since it causes problems such as scratches on the surface of, it is preferable to use it by touching it lightly.

The yarn debris or the like that adheres to the surface of the seat belt a during weaving or conveyance does not need to be removed because the change in the contact pressure applied to the vibration detector is significantly smaller than that of the unevenness defect. In the example, the woven seat belt a is wound around the guide roller V11, is guided in the traveling direction b1 while being in contact with the guide roller V11, and is in contact with the vibration detector I11 to continuously run, While being wound around the guide roller V12 and in contact with the guide roller V12, the guide roller V12 is guided again in the traveling direction b2 and comes into contact with the vibration detector I12 to continuously run.

Since the vibration detectors are arranged as described above by using the pair of guide rollers V11 and V12, the unevenness defect a1 on the front side of the continuously running seat belt a is detected by the vibration detector. The unevenness defect a2 on the back side is detected by I 11, and the vibration detector I 12 detects it.

Further, in order to realize the detection of the unevenness defect in the entire width direction of the seat belt a, as shown in FIG. 4, the surface of the vibration detector I 11 is made of thin SUS304 (stainless) with a thickness of 0.5 mm. The plate is attached and the change in contact pressure due to the unevenness defect transmitted to this plate is detected.

By using such a thin plate of SUS304, it is possible to prevent abrasion of the surface of the vibration detector I 11, and it is possible to detect uneven defects in the entire width direction of the seat belt a only by the vibration detector I 11. ing.

Since the occurrence of unevenness defects in the manufacture of seat belts is caused by defective raw yarns or abnormal weaving machines, the weaving machine is stopped and adjustments are made, so detailed information such as the location of occurrence is unnecessary. Is.

However, when applied to the purpose of detecting the generation position, it can be realized by arranging a plurality of vibration detectors in parallel in the width direction.

In the present embodiment, as shown in FIG. 5, the vibration circuit I 31 connected to the vibration detector I 11 and the band pass circuit I 41 connected to the amplification circuit vibrate so as to be close to the vibration detector. It is fixed to the detector holder I 51.

FIG. 6 is a circuit diagram of the amplifier circuit and the band pass circuit. The vibration detector I 12 for detecting the uneven defect a2 on the back side of the seat belt a has the same structure as the vibration detector I 11.

By arranging the vibration detectors I 11 and I 12 as described above, an output signal accompanying a change in contact pressure of the uneven defects a 1 and a 2 can be obtained, and the operation of the weaving machine can be controlled.

In this way, the signals output from the respective vibration detectors due to the change in the contact pressure applied to the respective vibration detectors by the concave-convex defects a1 and a2 are the amplification circuits I 31, which are connected to the respective vibration detectors. It is applied to the input terminal of I 32 and is amplified by a predetermined gain. The output signal amplified by each amplifier circuit is applied to the input terminals of the respective bandpass pass circuits I 41 and I 42 to remove the DC component and the high frequency noise component and output the unevenness defect signal.

In this embodiment, since the frequency component of the signal due to the change of the contact pressure due to the irregularity defect is about 2 Hz, each band pass circuit removes the DC component and passes the frequency component up to 3 Hz. I have to.

The unevenness defect signal output from each band pass circuit is input to the determination circuits III 11 and III 12 as shown in FIG. 7 and a plurality of predetermined reference levels corresponding to the unevenness defect of the seat belt are set. The size of the uneven defect is determined by comparison and determination. That is, since the signal level of the uneven defect signal is proportional to the size of the uneven defect, a plurality of thresholds are set to realize the size of the uneven defect.

The discrimination signal of the uneven defect detected by classifying the sizes in this way is input to the display control means IV. In the display control means IV, the occurrence of uneven defects is displayed by the uneven defect generation indicator IV 1 based on the determination signal output from each determination circuit.

The concave-convex defect generation / accumulation circuits IV 21 and IV 22 accumulate the judgment signals input from the respective judgment circuits for each size of the concave-convex defects. The output of each uneven defect occurrence accumulation circuit is compared with the threshold value of the number of occurrences corresponding to the size of the uneven defect preset in the loom control circuit IV3, and when the predetermined threshold value is exceeded, the loom Be stopped.

According to the present embodiment, since the vibration detector is arranged so as to come into contact with the seat belt surface, when unevenness defects occur on the seat belt surface, the contact pressure between the seat belt surface and the vibration detector is increased. Therefore, the vibration detector can detect the change in contact pressure to detect the uneven defect.

Further, since the change of the contact pressure depends on the size of the uneven defect, the signal detected by the vibration detector is discriminated by a plurality of criteria to detect the size of the uneven defect stepwise. be able to. Further, the weaving machine of the seat belt can be controlled according to the detected unevenness defect signal.

In the above description, the seat belt is the object of the present embodiment, but it can be applied to the detection of irregularities of general fiber fabrics. Although a guide roller having an outer peripheral surface was used to prevent the seat belt from swinging, a straight side portion where the seat belt does not swing should be configured to install the unevenness detecting means above and below the seat belt. It is also possible to detect uneven defects. Further, although the seat belt is made to travel so as to move in contact with the vibration detector, the uneven defect can be detected by moving the uneven detection means.

[0062]

Second Embodiment In the first embodiment described above, it is possible to detect uneven defects on the surface of the seat belt. However, in a thick textile fabric such as a seat belt, uneven defects are also found on the edge of the fabric, that is, the ear. The detection of concave and convex defects occurring in the ear portion will be described below as a second embodiment.

The unevenness defect detection device according to the second embodiment is applied to the detection of unevenness defects on the end surface of an automobile seat belt, which is one of the textile fabrics, and will be described with reference to FIG.

As shown in FIG. 8, the concave-convex defect detecting device of the second embodiment has vibration detectors I 11, I 12 and vibration-proof rubbers I 21, I to which thin stainless steel plates are attached, as in the first embodiment. 22.Vibration detector holders I 51, I 52 that incorporate amplification circuits I 31, I 32 connected in close proximity to each vibration detector and band pass circuits I 41, I 42 connected to each amplification circuit An unevenness detecting means I including sensor guide devices I 61 and I 62 for moving each vibration detector holder in the front-rear direction and the left-right direction is provided.

Furthermore, the unevenness defect detection device of the second embodiment includes unevenness defect determination means III including determination circuits III 11 and III 12 connected to each band pass circuit of the unevenness detection means I, and each determination circuit. It is provided with an uneven defect determining means II including a display control means IV for controlling the operation of the loom as well as displaying the occurrence of the uneven defect by the output from the device.

Further, the uneven defect detecting device of the second embodiment guides the seat belt a in a state of contacting with a constant tension, and abuts against the end surface of the seat belt a so that the seat belt a does not swing in the width direction. Stopper s in contact is provided with rocking suppressing means V 1 composed of rollers formed at both ends.

As the vibration detector, an ultrasonic sensor which is an ultrasonic wave receiver is used as in the first embodiment.

The vibration detectors I 11 and I 12 are located on the upstream side of the rocking suppressing means V by adjusting the positions of the vibration detector holders I 51 and I 52 by the sensor guide devices I 61 and I 62, respectively. The seat belt a is arranged so as to be in light contact with both end surfaces of the seat belt a as in the first embodiment.

In this embodiment, the seat belt a is contact-guided by the rocking suppressing means V, and the end faces thereof contact the vibration detectors I 11 and I 12, so that the seat belt a continuously travels.

In this way, the signal output from each vibration detector due to the change in the contact pressure applied to each vibration detector by the concave-convex defects a1 and a2 was fixed in proximity to each vibration detector. It is input to the amplifier circuits I 31, I 32 and amplified by a predetermined gain.

The signal amplified by the predetermined gain in each amplifier circuit is applied to the input terminals of the band pass circuits I 41 and I 42 corresponding to each amplifier circuit, the DC component and the high frequency noise component are removed, and the signal is output as the unevenness defect signal. , Is input to the judgment circuits III 11 and III 12 corresponding to each band pass circuit, and is compared with a plurality of predetermined reference levels corresponding to the unevenness defect of the seat belt, and the size of the unevenness defect is determined and output as a determination signal. To be done.

The determination signal of the uneven defect detected by classifying the sizes in this way is input to the display control means IV. In the display control means IV, the occurrence of unevenness defect is displayed by the unevenness defect occurrence indicator IV 1 based on the determination signal input from each determination circuit.

Concavo-convex defect generation / accumulation circuits IV 21 and IV 22 accumulate the discrimination signals input from the respective determination circuits according to the size of the concave / convex defect. The output of each uneven defect occurrence accumulation circuit is compared with the threshold value of the number of occurrences corresponding to the size of the uneven defect preset in the loom control circuit IV 3, and when the predetermined threshold value is exceeded, the loom Is stopped.

The uneven defect detecting apparatus of the second embodiment having the above-mentioned operation is one in which the uneven defect detection of the seat belt surface of the first embodiment is applied to the uneven defect detection of the end face of the seat belt.

In both the first and second embodiments, the present invention is applied to the weaving process, but the present invention can be applied to other processes as well, and particularly in the detection process where the speed is higher than the weaving process, a sudden contact pressure is applied. Changes, the amplitude of the signal obtained from the vibration detector increases and the detection sensitivity also increases, which is practical.

In the fifth preferred embodiment of the present invention described above, a holder is provided on the concave-convex defect detection means I, and a vibration detector is fixed to the holder via a vibration-proof rubber. In this consideration, the vibration detector is preferably one whose surface is shielded by a smooth member with excellent wear resistance. It is also possible to bond a smooth thin member having excellent wear resistance to the surface of the vibration detector for use.

This is because the surface of the vibration detector is generally covered with a member such as aluminum. However, as shown in the present invention, since the vibration detector and the surface of the sheet-shaped fiber woven fabric make relative movement, This is because the surface of the vibration detector is worn when it is used for a long time. When the surface of the vibration detector is worn, the abrasion powder is mixed into the fiber fabric and the quality of the product is deteriorated.

In addition, the frequency-sensitivity characteristic of the vibration detector may change due to abrasion of the surface. For this reason, it is desirable that the surface of the vibration detector be bonded with a member having excellent wear resistance as much as possible.

As the above wear resistant member, a material having high rigidity that sufficiently transmits the change in the contact state due to the uneven defect to the surface of the vibration detector and does not cause a problem such as rust is desired. As this material, SUS304 (stainless steel), duralumin (aluminum alloy), ceramics, etc. can be considered.

Here, the detection characteristics when SUS304 and duralumin are used as the wear resistant member will be briefly described. However, both SUS304 and duralumin show the characteristics when the same vibration detector is used and the same irregularity defect is detected at a relative moving speed of 2 cm / sec.

FIG. 9 shows the relationship between the thickness of the wear-resistant member of SUS304 and duralumin and the peak value of the detection signal. The signal in FIG. 9 is obtained by amplifying the signal from the vibration detector 100 times.

As shown in FIG. 9, the peak value of the detection signal is attenuated by adhering the wear resistant member to the surface of the vibration detector. This is because the wear-resistant member and the adhesive are interposed between the unevenness defect and the surface of the vibration detector, and the change in the contact pressure due to the unevenness defect is absorbed.

Further, as shown in FIG. 9, when the thickness of the wear resistant member becomes thicker, the peak value tends to be slightly smaller, and it is desirable that the thickness of the wear resistant member is not too thick. As shown in FIG. 9, even if the detection signal peak value is reduced to about 2 [V] with a thickness of 1.5 mm, it has sufficient sensitivity for practical use. Furthermore, there is almost no difference between the materials of SUS304 and duralumin, and there is no problem with either material. Also, when ceramics were used, similar results were shown. The present inventors have used SUS304 having a thickness of 0.5 mm as the wear resistant member in consideration of wear resistance.

Further, a hard film such as a carbide, nitride, or nickel-line plating of several μm to several tens of μm may be formed on the surface of the vibration detector. The hard film forming treatment may be a chemical vapor deposition method, a physical vapor deposition method, wet plating or the like, which is usually used for the hard film forming treatment.

The characteristics of using SUS304 as the wear resistant member will be briefly described below. The wear resistant member can be easily prepared by processing a plate-shaped member having a certain thickness according to the shape of the surface of the vibration detector. However, it is desirable that the edges of the wear resistant member be rounded with sanding before use.

This is to prevent the edge of the abrasion resistant member from damaging the surface of the sheet-shaped fiber woven fabric as much as possible. The abrasion resistant member and the vibration detector may be fixed to the vibration detector by bolts or the like, but the easiest method is to fix them with an instant adhesive.

In the above-described method of using the wear resistant member, it is not always necessary to use a member having a shape corresponding to the shape of the surface of the vibration detector, and if a member longer than the width of the surface of the vibration detector is used, As shown in FIG. 10, it can also be applied to the detection of irregularities in the portion that does not directly contact the surface of the vibration detector.

Here, a brief description will be given of the detection characteristics of the irregularities on the surface of the sheet-shaped fiber woven fabric when the wear resistant member (SUS304, 0.5 mm) longer than the width of the surface of the vibration detector is used.

FIG. 11 shows the detection characteristics due to the same irregularity defect in the range of 30 mm from the center of the vibration detector using the vibration detector having a width of 10 mm. As shown in FIG. 11, the peak value of the detection signal decreases as the detection position of the uneven defect moves away from the vibration detector. This is because the longer the distance from the detection position to the vibration detector when the change in contact pressure due to the unevenness defect received by the wear resistant member is transmitted to the vibration detector, the greater the absorption of the vibration signal by the member and the vibration. This is because it attenuates. As shown in FIG. 11, at the detection position of 30 mm, the peak value is reduced to about 1.4 [V], but the sensitivity is sufficient for practical use.

However, by using the plate-shaped wear-resistant member, it is possible to detect irregularities on the surface of the sheet-shaped fiber woven fabric, which have different detection characteristics but are larger than the width of the vibration detector. However, since the detection signal level decreases as the detection position becomes farther from the vibration detector, it is desirable that the length of the wear resistant member be about 3 to 5 times that of the vibration detector.

By using the plate-shaped wear-resistant member as described above, it is necessary to arrange a large number of vibration detectors in parallel in the direction orthogonal to the longitudinal direction of the sheet in accordance with the width of the sheet-shaped fiber woven fabric. Therefore, the number of vibration detectors can be significantly reduced.

Further, as described above, by attaching the wear resistant member to the surface of the vibration detector by a method such as bonding, the wear resistant member is not worn even if it is used for a long period of time, and the quality of the product is impaired. The uneven defect can be detected without any

[0093]

[Effects of the Invention] As described above, according to the present invention, since the change in contact pressure due to the unevenness defect is detected by using the vibration detector without using optical means, the influence of ambient light, dust, etc. It is possible to provide a low-priced concave-convex defect detection device that can easily detect concave-convex defects without being affected, and since the concave-convex defects are detected as low-frequency signals due to changes in contact pressure, noise such as factory noise can be affected. It is possible to detect irregularities and defects stably. It has an advantage that an uneven defect detecting device can be provided.

Further, according to the present invention, the occurrence of the unevenness defect is displayed based on the size of the unevenness defect which is discriminated stepwise by the unevenness defect determining means, and the loom etc. is displayed according to the size and the frequency of occurrence of the unevenness defect. It is possible to control the operation of the above, prevent overlooking of uneven defects and improve work efficiency.

Further, according to the present invention, by forming a wear-resistant member on the surface of the vibration detector, the wear of the surface of the vibration detector during long-time use is prevented, and the abrasion powder is removed from the textile fabric. It has the advantages of preventing the deterioration of the product quality due to mixing and also preventing the deterioration of the frequency characteristics of the vibration detector caused by the abrasion of the surface.

According to a preferred embodiment of the present invention, the unevenness detectors on the front and back of the sheet-like fiber fabric are arranged in contact with each other, whereby unevenness defects on the front and back are simultaneously produced by one run of the sheet-like fiber fabric. It has the advantage of being detectable.

In addition, according to a preferred embodiment of the present invention, since the unevenness detecting means can be moved and scanned in the width direction of the sheet-shaped fiber woven fabric by the sensor guide device, a constant width can be obtained by the vibration detector of the strap. This has the advantage that it is possible to easily detect irregularities on the surface of the sheet-shaped fiber woven fabric having the above.

Further, according to a preferred embodiment of the present invention, the bandpass filter removes contact noise caused by the contact movement between the sheet-shaped fiber woven fabric detected by the vibration detector and the vibration detector. The S / N ratio can be improved.

Further, according to a preferred embodiment of the present invention, the sheet-like fiber is further provided with a vibration suppressing means for suppressing the vibration of the woven fabric by a woven fabric guide device for guiding the sheet-like fiber woven fabric with a constant tension. The oscillation of the fabric is suppressed, and stable contact running between the vibration detector and the sheet fiber fabric is secured.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the configuration of the present invention.

FIG. 2 is an example of a signal waveform when an uneven defect contacts a vibration detector and relatively moves.

FIG. 3 is a signal waveform in which contact movement noise is removed and only a signal specific to the unevenness defect is filtered.

FIG. 4 is a schematic diagram showing the configuration of the present invention.

FIG. 5 is a schematic diagram showing the configuration of the unevenness detecting means in the present invention.

FIG. 6 shows an example of a circuit configuration of an amplifier circuit and a bandpass circuit according to the present invention.

FIG. 7 is a schematic configuration diagram of the unevenness determining means in the first embodiment of the present invention.

FIG. 8 is a block diagram showing a second embodiment of the present invention.

FIG. 9 is a plot diagram of the thickness of the wear-resistant member of SUS304 and duralumin and the peak value of the detection signal.

FIG. 10 is a configuration diagram of a vibration detector according to an embodiment of the present invention.

FIG. 11 is an example of unevenness detection characteristics of the surface of the sheet-shaped fiber woven fabric.

[Explanation of symbols]

 I Concavity / convexity detection means II Concavo-convex defect determination means III Concavo-convex defect determination means IV Display control means V Swing suppression means

Claims (3)

[Scope of utility model registration request] 1. An unevenness detecting means provided with a vibration detector that outputs an electric signal in response to a change in pressure or mechanical vibration, and the vibration detector is arranged so as to come into contact with a sheet-shaped fiber fabric, Moving means for relatively moving the sheet-like fiber fabric and the unevenness detecting means, and unevenness defect determination for comparing and determining a predetermined reference level corresponding to the unevenness defect of the sheet-like fiber fabric and the output level of the unevenness detecting means An apparatus for detecting irregularities in a sheet-shaped fiber woven fabric, including: 2. The unevenness defect determination means comprises a determination circuit for making a stepwise comparison determination of a plurality of predetermined reference levels corresponding to the unevenness defect of the sheet-shaped fiber woven fabric and the output level of the unevenness detection means. Means and display control means for displaying and controlling the irregularity defects, the irregularity defect occurrence accumulating means for accumulating and counting the irregularity defects according to the size based on the output of the irregularity defect determining means, and displaying the irregularity defects 2. A display control means comprising: an uneven defect generation display means for outputting; and a loom control means for generating a signal for controlling a loom based on the output of the uneven defect occurrence accumulating means.
A device for detecting irregularities in a sheet-shaped fiber woven fabric as described above. 3. The unevenness defect detecting device for a sheet-shaped fiber woven fabric according to claim 1, wherein a wear-resistant member is formed on the surface of the vibration detector that comes into contact with the surface of the sheet-shaped fiber woven fabric.