JPH0823531B2 - Rubber belt appearance inspection method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting the appearance of a rubber belt, and more specifically, it has defects such as cracks, chips and dents on the surface of the rubber belt, and defective polishing, carbon black mixed in the rubber belt, short fibers, Alternatively, the present invention relates to a method for inspecting the appearance of a rubber belt, which detects the shade of color caused by the dispersion of other fillers on the surface.

[0002]

2. Description of the Related Art Conventionally, in the manufacture of V-ribbed belts, a vulcanized cylindrical rubber sleeve is cut into a predetermined width, and the rubber sleeve is hung on a driving roll and a driven roll under a constant tension while running. The rotating grinding wheel was engaged with the rubber sleeve, and the rubber sleeve was provided with a plurality of ribs. The obtained rubber sleeve was cut into a predetermined width in the next step and finished into individual belts.

Then, the operator visually observes defects such as cracks, chips, and dents on the polished surface of the individual belts, or defective surfaces such as defective polishing of the belt surface, carbon dispersion, cut yarn dispersion, and foreign matter. I was inspecting the shade of color. If such a defect portion or a light and shade portion exists on the belt surface, when the belt is run, a crack may grow from the defect portion or the light and shade portion and cause the belt to be damaged early. It was an important step in maintaining the quality of the belt.

[0004]

However, although the visual judgment of the operator is tentatively standardized, it is somewhat different depending on the individual and largely depends on the feeling of the operator. In addition, a skilled worker is required to make a quick quality decision. Therefore, in the past, it has been attempted to automate this visual inspection. For example,
The inspected object is irradiated with light and the reflected light is used by a PSD element (semiconductor position detecting element) to measure the depth of the recessed portion, which is an abnormal portion, and an abnormal signal is emitted when the depth exceeds a certain value. It was However, even with this inspection apparatus, if the depth of the depression is small, there is a large problem that cannot be detected, and the accuracy of the inspection is poor. Therefore, it has been difficult to perform a visual inspection of a product having a small dent portion such as a rubber belt.

In addition, when the surface of the rubber sleeve after polishing the surface has polishing debris or dust adhering to it, the inspection device may detect this, and even if the surface is normal, it is detected as defective and reliability is high. There was also a problem of decline. The present invention solves such a problem, and removes dust adhering to the object to be inspected to obtain an accurate inspection state, and inspects small irregularities and shades of color, and An object of the present invention is to provide a method for inspecting the appearance of a rubber belt, which enables an appearance inspection in a state close to visual judgment by an operator.

[0006]

That is, according to the present invention, which is adapted to the above object, the surface of an object to be inspected, which is made of a rubber belt, has unevenness such as cracks, chips, and dents, and the surface of an additive mixed in the rubber belt. This is a method for inspecting the appearance of a rubber belt that detects the shade of color that occurs due to dispersion.While the rubber belt is hung on a drive roll and a follower roll and run under a certain tension, the roll comes into contact with the running rubber belt surface. The rubber belt is prevented from shifting to one side, and a brush is brought into contact with the surface of the rubber belt while running to remove dust and the like adhering to the rubber belt.The laser beam is projected on the rubber belt surface while moving along the width direction of the rubber belt. receiving light vital reflected light measured displacement data, mark the rubber belt surface when the variation value of the displacement data becomes a value outside the range of the judgment value Ri, a light quantity level of the laser beam
In the relationship of displacement accuracy, the displacement accuracy is sharp when the light level is changed.
It is installed near the point where
This is a method for inspecting the appearance of a rubber belt in which the offset value of the amplifier is set to be large .

Further, according to the present invention, the surface image of the rubber belt is captured while moving along the width direction of the rubber belt, and the obtained image signal is converted into a digital signal by image processing to detect the shade of color, and the detected value is a judgment value. It also includes a method for inspecting the appearance of a rubber belt that marks the surface of the rubber belt when it is out of the range.

[0008]

According to the appearance inspection method of the present invention, the rubber belt is hung on the driving roll and the driven roll, and while being run under a constant tension, the roll prevents the rubber belt from shifting to one side and the brush is running. The appearance of the rubber belt is accurately inspected by contacting the surface of the rubber belt to remove dust, etc. adhering to the rubber belt, and laser light with excellent monochromaticity and sharp directivity is moved along the width direction of the rubber belt. Displacement data is measured by projecting and receiving light on the surface of the rubber belt while performing, and when the variation value of the displacement data is outside the range of the judgment value, a mark is put on the surface of the rubber belt and the defective portion is displayed. It is a thing.

Further, in the present invention, an image of the surface of the rubber belt is captured while moving along the width direction of the rubber belt, and the obtained image signal is converted into a digital signal by image processing to detect the shade of color, and the surface of the rubber belt is detected. When carbon black, short fibers, or other filler is dispersed, this part is regarded as a defective part and marking is made on the surface of the rubber belt.

Here, the laser light receiving portion has a resistance layer, and the light energy received by the light receiving portion flows as a photocurrent through the resistance layer and is divided into two electrodes for extraction.
At this time, if the currents drawn from the electrodes are I ₁ and I ₂ , the light amount = I ₁ + I ₂ , and the displacement = (I ₁ −I ₂ ).
/ (I ₁ + I ₂ + B). However, B is the offset value of the amplifier.

Therefore, since the reflected light from the normal portion of the rubber belt always enters the center of the resistance layer, the currents I ₁ and I ₂ are equal and the displacement (distance) is zero, while the reflected light from the uneven portion of the rubber belt. Since light is incident away from the center of the resistance layer, I ₁ and I ₂ are different from each other, and displacement occurs.

The present invention utilizes the characteristic that the laser light amount decreases when a defective portion is detected and the relational expression of the displacement. When the laser light amount becomes smaller than a certain value, the displacement data becomes larger than the true value. Then, an error is caused, and by utilizing this, it becomes possible to detect a defect with a small change in displacement data.

In the image processing, the gray level difference of an image signal which is an analog signal is divided by a certain boundary line, divided into binary black and white and digitized, and data larger than the boundary line is counted and compared with a judgment value. Therefore, it is possible to detect a portion having different gloss from the base rubber of the rubber belt, for example, defective polishing, carbon dispersion, cut yarn dispersion, and foreign matter.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of a V-ribbed belt having a defective portion, FIG. 2 is a perspective view of a V-ribbed belt having another defective portion, and FIG. 3 shows an inspection apparatus used in the appearance inspection method for a rubber belt of the present invention. It is a schematic diagram. According to the method of the present invention, it is possible to detect the minute cracks 2 existing on the surface of the rubber belt 1 polished by the polishing wheel and the cut yarns 3 dispersed on the surface.

The inspection device 4 used for this detection includes a belt traveling unit 5 for traveling the rubber belt 1 which is an object to be inspected,
A belt positioning roll 6 that prevents the running of the rubber belt 1 in one direction while traveling and allows the rubber belt 1 to travel accurately, and the rubber belt 1.
At least one set of a laser processing device 8 including a brush portion 7 for removing dust and the like adhering to the surface of the rubber sheet, a laser portion 9 and a mark portion 10 for marking the surface of the rubber belt 1 when an abnormality is detected by the laser portion 9, The image processing device 11 includes an illumination unit, a camera, and an image processing unit.

Here, the belt running unit 5 includes a drive roll 13 connected to a prime mover and a driven roll 14 movable.
It consists of On the other hand, the driven roll 14 has its bearing 1
5 is fixed to the tip of the rod 16 of the cylinder. The bearing 15 of the driven roll 14 has a slide portion 17 fixed to the bearing 15 fitted to a pair of guide rails 18. Therefore, the driven roll 14 horizontally separates from the drive roll 13 along the guide rail 18 and approaches the drive roll 13.

The belt positioning roll 6 is the drive roll 1
It is located immediately above 3 and moves up and down by the operation of the cylinder, and comes into contact with the surface of the rubber belt 1 suspended by the driving roll 13 and the driven roll 14 under a predetermined tension. As a result, the rubber belt 1 with the core wire buried therein does not deviate in one direction even when running. Particularly, when inspecting the rubber belt 1 having a plurality of ribs in the width direction, a belt positioning roll 6 that fits into the rib may be used.

The brush portion 7 is composed of two brushes, a rotating brush 20 and a fixed brush 21, and both of the brushes 20 and 21 are in contact with the driven roll 14. The rotating brush 20 is connected to a prime mover 22 via a transmission belt 23 and removes dust such as rubber scraps attached to the running rubber belt 1. Further, the fixed brush 21 has a function of surely removing dust and the like not removed by the rotating brush 20. Therefore, the fixed brush 21 needs to be located behind the rotating brush 20 with respect to the traveling direction of the rubber belt 1.

The laser processing device 8 comprises at least one set of laser portions 9 and a mark portion 10 for marking the surface of the rubber belt 1 when an abnormality is detected by the laser portions. The laser processing device 8 is installed on the base and moves in the width direction of the rubber belt 1 by the operation of the prime mover. Further, the laser processing device 8 moves to the drive roll 13 side.

The laser unit 9 projects laser light toward the surface of the rubber belt 1 which is running and receives light reflected from the belt surface. The light receiving unit 25 has a semiconductor position detecting element (PSD), and the light energy received by the resistance layer of the PSD is converted into photocurrent and divided into two electrodes from the resistance layer to be extracted. The laser light is 400 to 10
00 monochromatic with those having a wavelength of nanometer, sharp directivity, and can correctly detect the state of the rubber belt 2 surface for high degree of focusing.

At this time, the current drawn from the electrode is I
_{If 1} and I ₂ , the light quantity = I ₁ + I ₂ , and the displacement =
(I ₁ −I ₂ ) / (I ₁ + I ₂ + B). However,
B is the offset value of the amplifier. Therefore, when the reflected light from the normal portion of the rubber belt enters the center of the preset resistance layer, the currents I ₁ and I ₂ become equal and the displacement becomes zero. On the other hand, since the reflected light from the uneven portion of the rubber belt enters away from the center of the resistance layer, I ₁ and I ₂ are different, and displacement occurs. The defective portion can be found by detecting such a change in the displacement data.

Moreover, according to the present invention, the defective portion can be detected even when the change in the displacement (distance) data is small. That is, the laser light amount decreases when a defective portion is detected, but as shown in FIG. 4, when the absolute value of the laser light amount falls below a certain value, the displacement accuracy is extremely reduced, and the displacement data is larger than the true value. Error occurs. That way, it is possible to detect the change was small portion of the original displacement data as a defect. For this reason,
In the present invention, it is necessary to set the light amount level in the vicinity of where the displacement accuracy starts to suddenly decrease. Further, since the deviation amount from the true value of the displacement data is determined by the offset value B of the displacement type amplifier, this value is fixed. In FIG. 4, the laser light amount (%) is calculated so that the maximum value that can be amplified by the amplifier is 100%.

In this way, cracks, cracks, dents, etc. are detected. First, as shown in FIG. 5, cracks, cracks, etc. are continuously detected by the runout value of the displacement data for a belt length of 1 mm. Then, the maximum value (PP value) is compared and evaluated with the determination value. In addition, as for the dent detection, as shown in FIG. 6, the average value of the displacement data of the constant section (a) is calculated and continuously compared with the same average value separated by the distance L, and the maximum of the measured value (difference) is obtained. Evaluate the value against the judgment value.

The mark portion 10 is activated when the laser portion 9 detects cracks, chips, dents, etc. When an abnormal signal is detected, a cylinder incorporated therein operates to cause the pen 26 to project. Put a linear mark on the defective portion of the surface of the rubber belt 2.

The image processing apparatus 11 is composed of an illumination unit 28, a camera 29 and an image processing unit 30. The image processing device 11 is installed on a base and moves in the width direction of the rubber belt 1 by the operation of the prime mover. The lighting unit 2
Reference numeral 8 illuminates the surface of the rubber belt 1 so that, for example, a CCD device type camera 29 captures an image by the reflected light from the surface of the rubber belt 1. The image processing unit 30 divides the image signal (analog signal) captured by the camera 29 into black and white binary at a boundary line that can be arbitrarily set, and digitizes it.
Using this digital signal, the areas of defective portions that are whiter and darker than the base rubber are counted, and compared with the pass / fail judgment value.

As the camera 29, for example, a video camera having a CCD element can be used, and the white defective portion and the black defective portion which can be captured by the camera are dispersed in the carbon or the cut yarn existing on the surface of the rubber belt 2, Alternatively, it is white ZuO, a metal piece, or a black foreign substance. If the image processing device 11 detects defects such as poor polishing, carbon dispersion, cut yarn dispersion, and foreign matter, the mark portion 10 is activated, and the cylinder incorporated therein is activated to cause the pen 32 to protrude. It is possible to put a linear mark on the defective portion on the surface of the rubber belt 1. Further, with respect to the lump of carbon and the cut yarn, by applying a noise filter to the image processing unit 30, it is possible to process only the data having several pixels in succession.

A method for inspecting the appearance of a rubber belt using the above device will be described below. First, the driven roll 14 of the belt traveling unit 5 is brought closer to the drive roll 13 side, the rubber belt 1 is installed on the two rolls 13 and 14, and then the driven roll 14 is separated from the drive roll 13 to apply tension to the rubber belt 1. . Along with this, the belt positioning roll 6
Is moved to contact the surface of the rubber belt 1, and at the same time, the rotating brush 20 and the fixed brush 21 of the brush portion 7 contact the rubber belt 1. At this time, the drive roll 13 is rotating and the rubber belt 1 is running. by this,
It is possible to remove dust adhering to the rubber belt 1 to clean the surface of the belt, thereby improving the reliability of the visual inspection.

At this time, the laser portion 9 and the mark portion 10 of the laser processing device 8 are located at one end of the rubber belt 1,
While moving toward the other end, the laser unit 9 is operated to inspect the surface of the rubber belt 1 for defects such as cracks, chips and dents. When the laser portion 9 detects a defective portion, the pen 26 of the mark portion 10 projects to form a linear mark on the surface of the rubber belt 1. At this time, the movement of the laser processing device 8 is stopped.

Further, like the laser processing device 8, the illumination unit 28 and the camera 29 of the image processing device 11 are also equipped with the rubber belt 1.
The image processing is performed on the surface of the rubber belt 1 while the rubber belt 1 is positioned at one end and moved toward the other end to detect the presence of polishing defects, carbon dispersion, cut yarn dispersion, and foreign matter. When the presence of these defective parts is detected, the pen 32 of the mark part 33 is detected.
Protrudes to form a linear mark on the surface of the rubber belt 1. At this time as well, the movement of the image processing apparatus 11 is stopped. When the inspection is completed, the rotation of the drive roll 13 is stopped, the driven roll 14 is brought closer to the drive roll 13 side, the belt positioning roll 6 is separated from the rubber belt 1, and then the rubber belt 1 is taken out.

[0030]

As described above, according to the appearance inspection method for a rubber belt of the present invention, the rubber belt is hung on the driving roll and the driven roll, and the rubber belt is moved by the belt positioning roll while traveling under a constant tension. The reliability of the visual inspection is improved by preventing the deviation in the direction and by removing dust and the like adhering to the running rubber belt surface by the operation of the brush portion and adhering to the rubber belt. Then, by using laser light, it is possible to detect defects such as cracks, chips, and dents on the surface of the rubber belt, and by using image processing, polishing defects, carbon dispersion,
It is possible to correctly inspect for the presence of white defects and black defects such as cut yarn dispersion and foreign matter, which are whiter than the base rubber, and it is possible to confirm their positions by marking defective parts and black and white defective parts. Enables visual inspection in a state close to the operator's visual judgment.

[Brief description of drawings]

FIG. 1 is a perspective view of a rubber belt having a defective portion.

FIG. 2 is a perspective view of a rubber belt having another defective portion.

FIG. 3 is a schematic view of a rubber belt appearance inspection device used in the rubber belt appearance inspection method of the present invention.

FIG. 4 is a graph showing a relationship between a laser light level and displacement accuracy.

FIG. 5 is a diagram showing displacement data for detecting cracks and chips on the surface of the rubber belt.

FIG. 6 is a diagram showing displacement data for detecting a dent on the surface of a rubber belt.

[Explanation of reference numerals] 1 rubber belt 5 belt running part 6 belt positioning roll 7 brush part 8 laser processing device 9 laser part 10 mark part 11 image processing device 13 drive roll 14 driven roll 20 rotating brush 21 fixed brush 28 illumination part 29 camera 30 Image processing unit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-1-308950 (JP, A) JP-A-63-135252 (JP, A) JP-A-63-180323 (JP, A) JP-A-60- 209141 (JP, A) JP-A 1-296145 (JP, A) JP-A 1-247349 (JP, A) Actually open 3-21021 (JP, U) Actually open 52-80688 (JP, U)

Claims (3)

[Claims] 1. A method for inspecting the appearance of a rubber belt, which detects unevenness of a surface of an object to be inspected, which is formed of a rubber belt, such as cracks, chips, and dents, and the density of colors caused by dispersion of additives mixed in the rubber belt to the surface. Yes, while the rubber belt is hung on the driving roll and the driven roll and run under a constant tension, the roll is brought into contact with the surface of the running rubber belt to prevent deviation of the rubber belt and the running rubber belt. A brush is brought into contact with the surface to remove dust and the like adhering to the rubber belt, and the displacement data is measured by projecting and receiving laser light while moving the laser beam along the width direction of the rubber belt and receiving it. When the variation value of is outside the range of judgment value, a mark is put on the surface of the rubber belt.
In this relationship, the displacement accuracy of the light intensity level drops sharply.
Installed near it and increase the margin of deviation from the true value.
The appearance inspection method for rubber belts is characterized by setting the offset value of the amplifier as described above. 2. The surface image of the rubber belt is captured while moving along the width direction of the rubber belt, and the obtained image signal is converted into a digital signal by image processing to detect color shading, and the detected value is outside the range of the judgment value. The appearance inspection method for a rubber belt according to claim 1, wherein a mark is attached to the surface of the rubber belt when it becomes. 3. The appearance inspection method for a rubber belt according to claim 1, wherein the inspection surface of the rubber belt is a surface polished by a polishing wheel.