JP3870140B2 - Driving transmission belt inspection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving transmission belt inspection method for automatically detecting defects generated on a belt end face in a manufacturing process of a driving transmission belt such as a CVT belt.
[0002]
[Prior art]
The CVT belt incorporated in a continuously variable transmission such as an automobile is a laminate of about 10 metal belts. These metal belts are laminated after being polished by barrel polishing in advance, but if wear flaws, processing flaws, dent marks, three wrinkles, etc. occur on the belt end surface, the belt breaks starting from wrinkles during use. Sometimes.
[0003]
Therefore, conventionally, a single layer CVT belt or a stacked CVT belt is placed on a rotary table and rotated at a low speed, and the belt end surface is photographed with a magnifying glass, and an inspector performs an inspection while viewing an image displayed on a monitor. I was doing it. When the inspector finds a wrinkle, the rotary table is stopped and the corresponding portion is marked, and when the inspection on one side is completed, the belt is reversed and the opposite surface is inspected in the same manner. When the inspection of both end faces is completed, a secondary inspection is performed on the marked portion using the stereoscopic microscope in consideration of the depth information of the wrinkles, and the quality is determined.
[0004]
However, this conventional method has a problem that the rotation speed of the rotary table cannot be increased because the inspector visually observes the image displayed on the monitor, and it takes a long time to inspect one belt. . Further, when inspecting a CVT belt after lamination, foreign matters such as dust that have entered between the belts in the lamination process may be erroneously detected as wrinkles, and the inspection accuracy is lowered.
[0005]
[Problems to be solved by the invention]
In order to solve the above-described conventional problems, the present invention provides a drive transmission belt inspection method capable of accurately inspecting wear flaws, processing flaws, dent flaws, and the like existing on the belt end surface at a high speed. It was made.
[0006]
[Means for Solving the Problems]
The drive transmission belt inspection method according to the first aspect of the present invention, which has been made to solve the above-mentioned problems, sets the drive transmission belt to be inspected on the outer periphery of the rotary table and makes it closely contact the side surface of the rotary table by a presser roll. The belt end face is photographed with a two-dimensional camera or line sensor camera while rotating, and the both end faces of the belt are first detected from the brightness change of the image, and the distance between the detected end faces is calculated and compared with the actual thickness. If they match, a true end face is obtained. If they do not match, the previous point is used to obtain an edge-corrected image in which the influence of the meandering of the belt is corrected, and the belt end face profile and the image brightness in the belt thickness direction are obtained. It is characterized in that pass / fail judgment is performed using an automatic wrinkle detection logic using the relationship between Note that it is preferable to take a picture by installing a two-dimensional camera or a line sensor camera at a position where the illumination from the illuminating device including the high-intensity light source is regularly reflected by the end face of the drive transmission belt. According to a third aspect of the present invention, there is provided a drive transmission belt inspection method in which a profile obtained by measuring the height displacement of the belt end face in the thickness direction is measured for the drive transmission belt in which wrinkles are detected by the inspection method according to the first or second aspect. It is characterized by automatically measuring in the circumferential direction and performing a more accurate inspection.
[0007]
As shown in the embodiments described below, according to the drive transmission belt inspection method of the present invention, the end surface wrinkles of a single-layer drive transmission belt are increased to about 1 to 5 seconds per one optical inspection technique. Automatic inspection with high accuracy at speed. In the embodiment shown below, the drive transmission belt is a CVT belt, but the present invention conveys precision parts such as printing machines, copiers, robots, OA printers, precision equipment drive belts, semiconductor parts, electronic / electric parts, etc. Belts for high temperature parts such as drying furnaces and heating furnaces, belts for high temperature parts such as fired parts, belts for transporting sanitary products such as food, chemicals and pharmaceuticals, belts for precision inspection It can be applied to inspection of various drive transmission belts.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments in which the present invention is applied to inspection of a CVT belt will be described below.
FIG. 1 shows an embodiment of the invention of claim 1, wherein 1 is a rotary table having an outer peripheral length substantially equal to the inner peripheral length of the CVT belt, and CVT belt B (single layer CVT before lamination) to be inspected. The belt is set on the outer periphery so that the end surface is on the upper side as shown in the figure. In this embodiment, the length of the CVT belt B is 500 to 700 mm.
[0009]
Reference numeral 2 denotes an illuminating device, and 3 denotes an imaging system arranged at a position where the illumination light from the illuminating device 2 is regularly reflected by the end face of the CVT belt B. Although a halogen lamp or a metal halide lamp is used as the illuminating device 2, any light source can be used as long as the illuminance is stable and the flicker does not occur. However, the illumination device 2 is preferably provided with a high-intensity light source. In this embodiment, the light emitted from the high-intensity light source is guided to the convex lens of the projector 7 by the optical fiber cable 6 and collected on the end face of the CVT belt. It is illuminated and has a high illuminance of 300,000 lux. Such high illuminance is effective for high-speed inspection of the CVT belt B described below. In order to accurately inspect the end face of the CVT belt B, the angle α shown in FIG. 1 (A) is about 0 ° to 30 °, preferably about 10 °.
[0010]
The imaging system 3 is a two-dimensional camera or a line sensor camera provided with a two-dimensional CCD element or a line sensor element as an imaging element, and photographs the end face of the CVT belt B. The imaging system 3 is 1 to 50 μm in the belt thickness direction and the belt longitudinal direction by a magnifying glass. In this embodiment, the lens magnification is set so that the resolution in the belt thickness direction is 3 μm, and the resolution in the belt longitudinal direction is also 3 μm while the rotary table 1 is stopped. However, the resolution in the longitudinal direction of the belt is actually lowered due to the rotational speed of the rotary table 1.
[0011]
In order to prevent a decrease in resolution in the belt longitudinal direction, the rotational speed may be lowered than the cycle time determined by the scanning frequency of the image sensor, but the inspection time will be longer. Therefore, in order to rotate the turntable 1 quickly without deteriorating the wrinkle image to be inspected, the resolution in the longitudinal direction of the belt is set to 10 μm here. Further, a line sensor element of 1024 bits was used, the scanning frequency was set to 40 MHz, and the entire circumference of the CVT belt B having a length of 500 to 700 mm could be inspected in about 1 to 5 seconds. However, if the size of the eyelid to be inspected is large, the resolution can be reduced to 50 μm.
[0012]
The image of the imaging system is subjected to edge correction processing by the image processing board 4, and quality is determined using a wrinkle automatic detection logic using the relationship between the belt end face profile and the image luminance. First, the contents of image correction will be described.
[0013]
As shown in FIG. 1, a presser roll 5 is provided on the side of the rotary table 1, and the CVT belt B is brought into close contact with the side surface of the rotary table 1. As a result, meandering of several μm occurs in the thickness direction as shown in FIG. In order to correct this, first, both end faces of the belt are detected as indicated by arrows. In order to reliably perform this detection, it is preferable to adjust the positions of the illumination device 2 and the imaging system 3 so that the outside of the CVT belt B appears white.
[0014]
As shown in FIG. 3, both end faces of the CVT belt B are inclined, and the illumination light does not reflect regularly, so that it appears black. Therefore, a point having a certain luminance or less from the outside of both end faces is detected as an end face. However, as shown in FIG. 2B, the point may not be a true end surface due to wrinkles or irregularities on the end surface. Therefore, the detected distance between both end faces is calculated and compared with the actual thickness. If they match, the true end face is obtained. If they do not match, the previous point is adopted without adopting those points. In this manner, an edge corrected image in which the influence of the meandering of the belt is corrected can be obtained.
[0015]
Next, the relationship between the belt end face profile and the image luminance will be described. In FIGS. 3, 4, 5, and 6, the left side is an image, and the right side is a cross-sectional profile in the thickness direction. FIG. 3 shows an image of a normal product, in which the luminance on the inner side from both end faces is low and the luminance at the center is high. This is because regular reflection light is not received because both end portions are inclined, and regular reflection light is received because the central portion is flat.
[0016]
FIG. 4 is an image and a cross-sectional profile when there is a processing flaw. In this case, the inner slope from the end surface is roughened to become a flat surface, and the specularly reflected light is received to the vicinity of the end surface, and the portion with high luminance spreads. FIG. 5 is an image and a cross-sectional profile when there is a wear flaw. In this case, the central portion is cut to form a slope, and a low-luminance portion where regular reflection light is not received occurs. FIG. 6 is an image and a cross-sectional profile when there is a dent mark. This is a further expansion of the range of wear sores, and the low-luminance portion at the center is enlarged.
[0017]
Next, the wrinkle automatic detection logic using the relationship between the end face profile and the image luminance as described above will be described. As shown in FIG. 7, the image of the belt end face is divided in the thickness direction, and the continuous lengths of the respective portions with a certain luminance above and below the certain luminance are calculated. In this embodiment, the image is divided into seven in the thickness direction, and in addition, in order to investigate the central high-luminance portion in detail, the central portion is divided unevenly so as to be divided into five as shown in the figure.
[0018]
As for wear soot, it is characterized that a part of the central high-luminance part is missing. Therefore, if the part where the brightness on the line obtained by dividing the center part into 5 parts falls below a certain value, it is determined that the wear soot is a sore. To do. In this case, if this condition is satisfied for all of the five divided lines, it is possible to make a logic that allows some non-detection while over-detection is eliminated if it is determined that there is an abrasion flaw. Further, if the setting of the continuous section is lengthened on the three adjacent lines and shortened on the remaining two lines, the logic that allows the slight overdetection can be obtained by eliminating undetection.
[0019]
Since the above-mentioned wear marks are deeper and larger than the wear marks described above, they can be detected by the same logic if the low brightness level in the wear marks is set lower and the low brightness section is set longer. The feature of the processing ridge is that the slope from the end face to the center is flattened, and the regular reflected light of the illumination is received to increase the brightness, so the length of the section above a certain brightness on the dividing line near the end face It can detect by calculating | requiring thickness. In the above description, the magnitude of the luminance is used. However, it is possible to detect wrinkles in the same manner using the change in luminance.
[0020]
The CVT belt B in which wrinkles are detected by the above method is marked and subjected to a secondary inspection. Although the secondary inspection can be performed by a conventional method, a method in which a profile obtained by measuring the height displacement of the belt end surface in the thickness direction is automatically measured in the belt circumferential direction to perform a more accurate inspection can be taken.
[0021]
FIG. 8 is an explanatory diagram. First, a normal profile is stored, and the profile of the marked portion is compared with the end face start point and the end face end point. If a logic that detects whether the absolute value of the difference between the two points exceeds a certain value by adding the squares of the differences between the two points is detected, Detection is possible.
[0022]
The drive transmission belt inspection method of the present invention can be fully automated by using a robot or the like that attaches / detaches the drive transmission belt to / from the rotary table. For example, the drive transmission belt inspection method is incorporated in the preceding stage of the CVT belt laminating apparatus. Can do.
[0023]
【The invention's effect】
As described above, according to the present invention, it is possible to automatically inspect wear wrinkles, processing flaws, dent flaws, etc. existing on both end faces of the drive transmission belt at a high speed and for a long time as in the past. It is not necessary to perform inspections by a large number of inspectors. In addition, the secondary inspection of only the drive transmission belt in which wrinkles are detected by the profile measurement can increase the productivity of the inspection process.
[Brief description of the drawings]
FIG. 1 is a front view (A) showing an embodiment of the invention of claim 1 and a left side view (B) of a main part.
FIG. 2 is an explanatory diagram of image correction.
FIG. 3 is a normal belt image and cross-sectional pull fill.
FIG. 4 is an image of a belt with a processing flaw and a cross-sectional pull fill.
FIG. 5 is an image of a belt with a wear flaw and a cross-sectional pull fill.
FIG. 6 is an image of a belt with a dent flaw and a cross-sectional pull fill.
FIG. 7 is an explanatory diagram of division of an image of a belt end surface for the wrinkle automatic detection logic.
8 is a cross-sectional pull-fill diagram showing an embodiment of the invention of claim 3; FIG.
[Explanation of symbols]
B CVT belt (drive transmission belt)
DESCRIPTION OF SYMBOLS 1 Rotating table 2 Illuminating device 3 Imaging system 4 Image processing board 5 Presser roll 6 Optical fiber cable 7 Floodlight

Claims (4)

The drive transmission belt to be inspected is set on the outer periphery of the rotary table, and the belt end surface is photographed with a two-dimensional camera or line sensor camera while rotating in close contact with the side surface of the rotary table with a presser roll , and the brightness change of the image First, by detecting the both end faces of the belt and calculating the distance between the detected end faces and comparing with the actual thickness, if they match, the true end face is obtained, and if they do not match, the previous point is adopted. An edge correction image obtained by correcting the influence of the meandering of the belt is obtained, and pass / fail judgment is performed using an automatic detection logic that uses the relationship between the belt end face profile and the image brightness in the belt thickness direction. Inspection method of transmission belt.   2. The drive transmission belt inspection method according to claim 1, wherein the two-dimensional camera or the line sensor camera is installed at a position where the illumination from the illuminating device having a high-intensity light source is regularly reflected on the end face of the drive transmission belt.   For a drive transmission belt in which wrinkles are detected by the inspection method according to claim 1 or 2, a profile obtained by measuring the height displacement of the belt end face in the thickness direction is automatically measured in the belt circumferential direction, and a more accurate inspection is performed. A method for inspecting a drive transmission belt.   The drive transmission belt inspection method according to claim 1, wherein the drive transmission belt is a CVT belt.

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