JP2009300181A - Inspection device and inspection system of tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device and an inspection system of a tube capable of performing appearance defect inspection of a transparent small-diameter tube highly accurately without being affected by a tube thickness part. <P>SOLUTION: In the device which is formed by arranging in due order in the optical axis direction, a light source 19, a slit plate 21 having a plurality of slits 34 in the tubular axis direction, a glass tube 15 transferred in the optical axis orthogonal direction, and an imaging device 20, the glass tube 15 is imaged by using the slit plate 21 as a background, and image processing is performed by an image processing apparatus 24, to thereby detect appearance defects of the glass tube 15. The slit plate 21 is formed so that, when being viewed through the glass tube 15, the slits 34 form an image in a narrower range than an inner diameter dimension of the glass tube 15, and that a slit outer shielding part 35b forms an image shielding the tube thickness part. The imaging device 20 photographs simultaneously both a slit image and an outer shape image of the glass tube 15 or the like. The image processing apparatus 24 detects the appearance defects of the glass tube 15 based on the slit image and the outer shape image or the like. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a tubular body inspection apparatus for detecting an appearance defect of a transparent tubular body transported in the tube axial direction, and a tubular body for inspecting a transparent tubular body continuously formed and drawn on a molding line. It relates to the inspection system.

  Conventionally, as an inspection apparatus for inspecting the appearance of a transparent tubular body, for example, there is an apparatus as shown in Patent Document 1. The one disclosed in Patent Document 1 is provided with an imaging device and a light source so as to sandwich a translucent glass tube that is continuously transported at a predetermined speed in the tube axis direction, and an image processing device captures a captured image captured by the imaging device. Image processing is performed, and a foreign matter defect or the like is detected in an inspection frame set on the inner side with reference to the position coordinates of the thickness light shielding portion due to the thickness of the glass tube. Then, with respect to fluctuations in the position of the glass tube, the setting position of the inspection frame is changed in accordance with the change in the position coordinates of the thick light-shielding portion corresponding to the fluctuation, and foreign matter defects and the like are detected. ing.

  This is a thick tube with a tube diameter of 23 mm to 32 mm, a wall thickness of about 2.4 mm, and a slow tube drawing speed of 10 m / min to 20 m / min. The tube can be inspected by following the position variation of the glass tube. However, the tube diameter is 2 mm to 4 mm, the wall thickness is 0.2 mm to 0.5 mm, and the tube drawing speed is 80 m / min to 400 m / min. In the case of a simple tube, the inspection frame that can be set on the inner side of the tube thickness light-shielding part is very small, and the tube drawing speed is relatively high, so that the position of the tube against vibration of the tube Corresponding processing by coordinates cannot catch up, the tube thickness part is reflected in the inspection frame, and the transmitted image is also detected, so it is not possible to accurately detect the appearance defect, and the non-defective product is judged as a defective product Will end up.

  For this reason, when inspecting the appearance defect of a transparent tubular body with a small tube diameter and a high moving speed, it is possible to inspect with high accuracy without being affected by the tube thickness portion. There is a demand for an inspection apparatus and an inspection system that can eliminate a decrease in yield.

In addition to Patent Document 1, for example, as shown in Patent Document 2, the surface of the tubular member is formed by forming an illumination region (bright region) and a shadow portion (dark region) on the surface of the tubular member using a slit. There are methods and apparatus for inspecting for defects. In Patent Document 2, the slit is not arranged so as to be the background with respect to the camera.
JP 2005-114645 A JP 2005-208054 A

  The present invention has been made in view of the situation as described above, and the object of the present invention is to provide a tube thickness portion even when inspecting the appearance defect of a transparent tube having a small tube diameter and a high moving speed. It is an object of the present invention to provide an inspection apparatus and inspection system for a tubular body that can be inspected with high accuracy without being influenced by the above-described method and can eliminate a decrease in yield due to erroneous determination.

The tubular body inspection apparatus and inspection system of the present invention are:
A tube inspection device includes a light source, an imaging device disposed opposite to the optical axis of the light source, and a light source transferred between the imaging device and the light source while rotating in the tube axis direction perpendicular to the optical axis. Photographed by the imaging device with a tube body transparent to light, a slit plate having a plurality of slits in the tube axis direction and disposed at a predetermined position between the tube body and the light source. An inspection apparatus including an image processing device that performs image processing on a captured image of the tubular body and detects an appearance defect of the tubular body from the captured slit image, wherein the slit plate is viewed through the tubular body. The slit is formed so as to be obtained as an image within a predetermined radial direction range narrower than the inner diameter dimension of the tubular body, and the outer light-shielding portion of the slit reduces the tube thick portion of the tubular body. It is formed to be an image that blocks light The imaging device is configured to simultaneously capture the outer shape image or the tube thickness portion image of the tubular body together with the slit image, and the image processing device is configured to capture the slit image and the outer shape image or the tube thickness. It is characterized by detecting the appearance defect of the tubular body based on the thick part image,
Furthermore, the slit plate has a position detection opening in the direction perpendicular to the slit for photographing the outer shape image or the tube thickness part image in the vicinity of the slit,
Furthermore, the imaging device has an imaging range equal to or larger than the diameter of the tube, and at least four pairs of the light sources are arranged with the light source so that the tube can be photographed over the entire circumference. And
Further, the image processing device detects the presence or absence of an influence on the slit image by the tube thick part by detecting the position of the tube based on the outline image or the tube thick part image. It is a feature.

  In addition, the tube inspection system has a molding line that continuously draws a glass tube, and a foreign object such as a transparent tube that is installed in the forming line and is continuously transferred in the tube axis direction at a predetermined tube drawing speed. The above-described inspection apparatus for detecting defects, a cutting apparatus for cutting the tube body after inspection by the inspection apparatus into a predetermined length, and a predetermined separation distance downstream of the inspection line in the transfer direction of the molding line. An exclusion device that eliminates a defective tubular body that has been determined to be defective by the inspection device among the tubular bodies that are installed at a position and has been cut by the cutting device, and that eliminates the defective tubular body by the exclusion device. Is set to be performed after elapse of a time calculated based on a predetermined separation distance between the inspection device and the exclusion device and the tube drawing speed from the time when a defect is determined in the inspection device. System It is.

  According to the present invention, even when inspecting the appearance defect of a transparent tubular body having a small tube diameter and a high moving speed, it is possible to perform inspection with high accuracy without being affected by the tube thickness portion, There is an effect that it is possible to eliminate a decrease in yield due to misjudgment.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 is a block diagram of the inspection system, FIG. 2 is a cross-sectional view of the inspection apparatus, FIG. 3 is a view for explaining the inspection apparatus, FIG. 4 is a plan view of the slit plate, and FIG. FIG. 4 is a diagram showing a screen displayed on the image processing apparatus.

  1 to 5, a transparent glass tube inspection system 1 that is a transparent tube body is configured such that a line of a tube drawing line 3 of a tube drawing device 2 by a Danner forming method is horizontal. An inspection device 4, a cutting device 5, and an exclusion device 6 are installed in that order along the existing portion. The tube forming apparatus 2 includes a glass melting container 8 that holds and stores a molten glass 7 melted by a glass melting furnace (not shown) at a predetermined temperature, and a glass flow outlet 9 formed at the bottom of the glass melting container 8. And a sleeve 11 that rotates in a predetermined direction at a predetermined rotational speed by a drive mechanism 10. The sleeve 11 is inclined at a predetermined inclination angle so that the tip is downward, and a gas pressure feed path 12 is provided through the sleeve 11 along the axis of the sleeve 11. Pressure gas is supplied through the gas pressure feed path 12. Blow air supplied from the source 13 is ejected from the opening of the tip.

  Then, the molten glass 7 whose viscosity is appropriately adjusted flows down in a ribbon shape from the glass flow-down port 9 of the glass melting container 8 and winds around the root-side surface above the sleeve 11. Thereafter, the wound molten glass 7 moves from the root side to the lower tip side by gravity and is formed into a tubular shape by blow air of a predetermined pressure ejected from the tip opening, and the inspection device 4 and the cutting device 5 in the tube drawing line 3. For example, a continuous glass tube 15 having a predetermined tube outer diameter of a diameter of 2 mm to 4 mm and a tube thickness of 0.2 mm to 0.5 mm and a predetermined tube thickness of The tube drawing is continuously performed in the tube axis direction while slowly rotating around the tube axis O.

  At this time, for example, the tube outer diameter of the glass tube 15 transferred along the tube drawing line 3 is measured by the first tube outer diameter measuring device 16 and the second tube outer diameter measuring device 17, respectively. Based on the input to the blow pressure control unit 18, the control of the pressurized gas supply source 13 is performed so that the outer diameter of the pipe becomes a predetermined dimension. As for the tube drawing speed v, although not shown, a predetermined tube drawing speed is maintained, for example, by measuring the speed of the glass tube 15 and adjusting the tube drawing machine 14, for example, 80 m / min to 400 m / min. ing.

  The inspection device 4 inspects the presence or absence of appearance defects due to foreign matter, bubbles, streaks, etc. in the translucent glass tube 15, and each of the four light sources 19, the imaging device 20, and the slit plate 21 is in the optical axis L direction. The light source 19 and the imaging device 20 are arranged opposite to each other, and further, a regular octagonal rectangular annular housing 22 is housed so that the slit plate 21 is disposed between the light source 19 and the imaging device 20. An image pickup unit 23 to which the glass tube 15 on the tube drawing line 3 is moved in a direction orthogonal to the center of the annular surface 22, and a control unit 25 having an image processing device 24 for processing a photographed image of the image pickup unit 23; A casing support (not shown) for supporting the annular casing 22 at an appropriate position on the pipe forming line 3 is provided. The slit plate 21 is disposed between the glass tube 15 and the light source 19, and the positional relationship between the glass tube 15, the imaging device 20, and the slit plate 21 is, for example, a diameter of 2 mm to 4 mm and a tube thickness of 0. The slit plate 21 is located at a distance of 30 mm from the center of the glass tube 15 that is .2 mm to 0.5 mm, and the imaging device 20 is located at a position of 145 mm from the center of the glass tube 15.

  The regular octagonal annular housing 22 constituting the imaging unit 23 is divided into eight small partitions 29 having the same shape by dividing the space between the eight outer walls 26 and the inner wall 27 by the eight partition walls 28. In each of the opposing small sections 29, the inner walls 27 are parallel to each other. Further, a light source 19 having a light diffusion plate 31 disposed on the front surface of a blue LED (light emitting diode) array 30 having a size of, for example, 100 mm × 100 mm is provided on the surface facing the other side chamber in each small section 29 on one side. The light emitted from the blue LED array 30 is transmitted through the light diffusing plate 31 and projected as light source light in the direction of the other small section 29 facing the power source 32.

  Each of the small sections 29 on the other side of the annular housing 22 has a photographing opening 33 having a predetermined diameter formed on one surface facing the small section, that is, a surface facing the light source 19. A CCD (solid state) having a predetermined photographing range in the section 29 and having a depth of field equal to or larger than the diameter of the glass tube 15 so that a clear image from the front to the back of the glass tube 15 can be obtained. The imaging device 20 composed of an imaging device) camera has its optical axis L passing through the center of the imaging aperture 33, intersecting the tube axis O of the glass tube 15 to be transferred at right angles, and reaching the center of the opposing light source 19. It is provided as follows.

  Accordingly, the imaging device 20 is arranged on one side of the circumference around the tube axis O of the glass tube 15 with the optical axis L shifted by 45 degrees from the adjacent one, and the optical axis L is the glass tube. Crossing at the same point of the 15 tube axes O, similarly, the light sources 19 corresponding to the imaging device 20 are located on the other side, and the imaging devices 20 and the light sources 19 are arranged in the same plane orthogonal to the tube axis O. Is done. Then, the imaging range between at least four imaging devices 20 is increased by arranging the imaging device 20 in the same plane orthogonal to the tube axis O by shifting the optical axis L by 45 degrees in this way. It is possible to overlap, and the entire circumference of the glass tube 15 can be photographed.

  The slit plate 21 disposed between the glass tube 15 and the light source 19 is formed of a thin steel plate or the like that is not thermally deformed by the heat of the transferred high-temperature glass tube 15. For example, three slits 34 having a width of 2 mm and a predetermined length are provided with an inter-slit light-shielding portion 35 a having a width of 2 mm so that defects such as chipping at the processing end do not occur in the tube axis direction of the glass tube 15. It is formed by laser processing or the like. With regard to the length of the slit 34, the glass tube 15 transported on the tube drawing line 3 is taken into consideration in consideration of the transfer speed of the glass tube 15, that is, the tube drawing speed v, the shooting interval of the imaging device 20 from shooting to the next shooting, etc. The tube 15 is configured so that it can continuously shoot all around the tube axis direction. By forming the slit 34, the slit plate 21 is provided with a slit outer light-shielding portion 35b having a width of, for example, 10 mm or more so that the thick portion of the glass tube 15 does not appear on the outer side of the slit 34. It is done.

  Further, the slit plate 21 has a position detection opening 36 for detecting the position of the glass tube 15 in the direction orthogonal to the slit 34 in the vicinity of one end side of the slit 34 so as to provide a light shielding portion therebetween. The position detection opening 36 allows the imaging device 20 to take an image of the outer shape or the tube thick portion of the glass tube 15. In order to detect the position of the glass tube 15, it is only necessary to photograph at least the outer shape or the tube thick portion on one side, and the size of the position detection opening 36 is also a size corresponding thereto.

  The slit plate 21 thus formed is arranged at a position away from the glass tube 15 by a predetermined distance so that the optical axis L passes through the center of the slit 34 at the center of the three slits 34. . Accordingly, in the image obtained by photographing the glass tube 15 with the imaging device 20 against the slit plate 21, the thick portion of the glass tube 15 is shielded by the slit outer light shielding portion 35 b of the slit plate 21 due to the refraction of the glass. Will not appear as an image.

  On the other hand, the images of the three slits 34 are obtained in the inner diameter portion excluding the tube thickness portion of the glass tube 15, that is, in a predetermined radial direction range narrower than the inner diameter dimension. About the radial direction range where the image of the slit 34 is obtained, when the glass tube 15 is transferred, it vibrates a little up and down, left and right, and at that time, the thick part of the tube overlaps the slit 34 and may be reflected. In the inspection of the glass tube 15 having no dimension, that is, 70% to 80% of the inner diameter of the glass tube 15, for example, the diameter is 2 mm to 4 mm and the tube wall thickness is 0.2 mm to 0.5 mm. The range is smaller than the inner diameter by 2 mm to 1.0 mm, and is adjusted by the position where the slit 34 is formed in the slit plate 21, the position of the slit plate 21 relative to the glass tube 15, and the like.

  In addition, the control unit 25 including the image processing device 24 that processes the captured image of the imaging unit 23 is a personal computer provided to process each captured image signal from each imaging device 20 constituting the image processing device 24. And the like, and a line control device 38 that receives the output signal from the image processing device 24 and controls the exclusion device 6 and the like. Then, in the individual processing device 37, when a captured image signal is input from the imaging device 20, predetermined image processing is performed using the preset initial setting value, threshold value, and the like, and the set program, After detecting a foreign substance or the like included in the photographed image and determining whether or not it is defective, an output signal is output to the line control device 38.

  In the image processing in the individual processing device 37, first, initial setting values and threshold values are set using the display screen of the individual processing device 37. The setting is performed, for example, with one pixel as one unit, and the shape, position, and the like of the slit image 40 in the non-defective glass tube 15 in the slit plate image 39 shown by cross hatching are input to the display screen of FIG. This is performed by inputting a threshold value such as a defective state of a striped pattern that is distorted by a foreign object or other defects. In FIG. 5, 41 is a glass tube image, 42a is a light shielding part image between slits, and 42b is a light shielding part image outside a slit.

  After the setting of each initial setting value, threshold value, and the like is completed, the captured image signal is received from the CCD camera of the corresponding imaging device 20 and the captured image is captured. Subsequently, various processes such as increasing the S / N ratio of the photographed image signal are performed to make it possible to determine whether the quality is acceptable. Subsequently, the quality determination unit determines whether the foreign matter or defect in the obtained image is good or bad. If the result of this determination is that the foreign matter or the like is defective, a defect signal is transmitted to the line control device 38, and if it is not defective, the next captured image signal is fetched to determine whether it is good or bad, and this is repeated. Thus, the appearance defect inspection of the continuous glass tube 15 is performed.

  In the individual processing device 37, the glass tube image 41 obtained through the position detection opening 36 is constantly checked for fluctuations in the position of the glass tube 15 to prevent reflection of the thick portion of the tube due to normal vibration or the like. For example, from the slit outer light-shielding portion 35b that is spread in the center direction by 0.2 mm to 1.0 mm on one side from the inner diameter position, the vibration in the vertical and horizontal directions of the glass tube 15 increases and protrudes due to some factor. Due to the influence of the part overlapping the slit 34 and being reflected, the distortion caused by the tube thickness part is regarded as defective, and the occurrence of an abnormality is reported so that a non-defective product is not judged as a defective product.

  Further, the line control device 38 that has received the failure signal, the separation distance Q1 between the inspection device 4 and the exclusion device 6, the transfer speed of the glass tube 15, that is, the tube drawing speed v, and the separation distance Q2 between the inspection device 4 and the cutting device 5. And the cutting length f of the glass tube 15 in the cutting device 5, the glass tube 15 f after cutting having a defect such as a foreign matter detected by the inspection device 4 is determined, and it is excluded from the tube drawing line 3. The operation of the exclusion device 6 is controlled. As a result, the glass tube 15f having a defect such as a foreign substance is excluded from the tube drawing line 3 in the rejecting device 6, and the glass tube 15f after cutting the non-defective product flows on the tube forming line 3 after the removing device 6. Then, it is transferred to the next process.

  By configuring as described above, the glass tube 15 formed and transferred on the tube drawing line 3 can be continuously inspected for foreign matters and the like, and the glass tube 15 is overlapped with the inspection range. Inspection can be performed while reducing false detections, and defective products can be automatically and reliably eliminated. As a result, the quality of the glass tube 15f after being cut to a predetermined length can be maintained at a predetermined quality level, and such an inspection can be performed without taking time and effort.

  In the above embodiment, a blue LED is used as the light source 19, but the light source light projected using the blue filter may be blue, and the light source light having the optimum wavelength is selected by the imaging device 20 to be used. It may be. Furthermore, the slit plate 21 is formed with three slits 34 in the tube axis direction of the glass tube 15 so that a striped pattern can be formed. It is also possible to form a plurality of slits in the oblique direction intersecting each other or in the perpendicular direction perpendicular to each other. Further, in order to detect the position of the glass tube 15, the outer shape or the tube thickness portion of the glass tube 15 is photographed through the position detection opening 36 provided in the slit plate 21. Instead, the outer shape of the glass tube 15 protruding from the slit plate 21 or the tube thick portion may be directly photographed.

It is a lineblock diagram showing the inspection system which is one embodiment of the present invention. It is sectional drawing of the inspection apparatus which is one Embodiment of this invention. It is a figure shown in order to demonstrate the test | inspection apparatus of one Embodiment of this invention. It is a top view of the slit board in one embodiment of the present invention. It is a figure which shows the screen displayed on the image processing apparatus in one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 ... Molding line 4 ... Inspection apparatus 5 ... Cutting apparatus 6 ... Exclusion apparatus 15 ... Glass tube 19 ... Light source 20 ... Imaging apparatus 21 ... Slit plate 24 ... Image processing apparatus 34 ... Slit 35b ... Slit outer light shielding part 36 ... Position detection Opening

Claims (5)

A light source, an imaging device disposed opposite to the optical axis direction of the light source, and a tube body transparent to the light source light transferred between the imaging device and the light source while rotating in the tube axis direction orthogonal to the optical axis; A slit plate having a plurality of slits in the tube axis direction and disposed at a predetermined position between the tube body and the light source, and photographing of the tube body photographed by the imaging device with the slit plate as a background An inspection apparatus including an image processing apparatus that performs image processing of an image and detects an appearance defect of the tubular body from a captured slit image,
The slit plate is formed so that the slit is obtained as an image in a predetermined radial direction range narrower than the inner diameter dimension of the tube body when viewed through the tube body, and the light shielding portion on the outer side of the slit. Is formed so as to be an image that shields the tube thick portion of the tube body,
The imaging device captures the outer shape image or the tube thickness part image of the tube together with the slit image,
The tube inspection apparatus according to claim 1, wherein the image processing device detects an appearance defect of the tube based on the slit image and the outer shape image or the tube thick portion image.   2. The tube according to claim 1, wherein the slit plate has a position detection opening in a direction perpendicular to the slit for photographing the outer shape image or the tube thickness portion image in the vicinity of the slit. Body inspection device.   2. The imaging apparatus according to claim 1, wherein the imaging apparatus has an imaging range equal to or larger than a diameter dimension of the tubular body, and at least four pairs of the light source are disposed with the light source so that the tubular body can be photographed over the entire circumference. The tube inspection apparatus described.   The image processing device detects the presence or absence of an influence on the slit image by a tube thick part by detecting the position of the tubular body based on the outer shape image or the tube thick part image. The tube inspection device according to claim 1.   2. A molding line for continuously drawing a glass tube, and detecting defects such as foreign matter in a transparent tube that is installed in the molding line and is continuously transferred in a tube axis direction at a predetermined tube drawing speed. The inspection apparatus described above, a cutting apparatus that cuts the tubular body after inspection by the inspection apparatus into a predetermined length, and a position separated from the inspection apparatus by a predetermined separation distance on the downstream side in the transfer direction of the molding line, An exclusion device that excludes a defective tube that has been determined to be defective by the inspection device among the tubes cut by the cutting device is provided, and the removal of the defective tube by the exclusion device is the inspection device. Inspection of a glass tube, which is set to be performed after a lapse of time calculated based on a predetermined separation distance between the inspection device and the exclusion device and the tube drawing speed from the point of failure determination at system

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