JP2008203149A - Method and device for inspecting wave-like cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve inspection efficiency and accurateness by automatically inspecting the wavelength of a wave-like cord in a rubber covering material formed to cover the wave-like cord with rubber. <P>SOLUTION: Light and shade in response to projections and recesses is formed, by irradiating the surface of the rubber covering material 70 with light from a light source 10 and irradiating each projection of the projections and recesses corresponding to the wave-like cord of the surface. Imaging images are analyzed by a control analyzer 30, by imaging the light and shade with an imaging means 20 and acquiring the images of the surface of the rubber covering material 70. First, in image analysis, bright parts are extracted from the imaging images; average density of pixels is successively calculated at each prescribed unit region that is overlapped mutually by a part from the images, and the difference in the average density among a plurality of the unit regions overlapped mutually a part is calculated over the entirety. The number of exceeding the threshold from the calculated values of the difference is counted to compare the counted number with a set value, corresponding to wave regulation of the wave-like cord so as to determine whether the wavelength of the wave-like cord is within the regulation. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a wavy cord inspection method and inspection apparatus for inspecting the wavelength of a wavy cord in a rubber-coated member formed by coating a wavy cord with rubber, and in particular, an inspection capable of automatically inspecting the wavelength of a wavy cord. The present invention relates to a method and an inspection apparatus.

  In general, a pneumatic tire has a plurality of belt layers in which cords such as steel and organic fibers are arranged between a carcass layer extending between a pair of bead cores and a tread rubber that is in contact with a road surface when the tire rolls. It has. As one of the belt layers, a corrugated belt layer (WAVY belt layer) in which a corrugated cord extending while being bent or curved substantially in the tire circumferential direction has been widely used (Patent Documents 1 and 2). reference).

  This corrugated belt layer is composed of a rubber-coated member in which one or a plurality of corrugated cords having a predetermined diameter are arranged and covered with rubber. When a green tire (raw tire) is molded, the rubber-coated member is used as a lower belt layer or the like. It is formed by winding one or more rounds on the outer periphery of another tire constituent member. Further, each wavy cord in the rubber covering member is formed to be regularly bent at a predetermined wavelength and amplitude, and is arranged in the rubber covering member in a predetermined pattern, for example, arranged in parallel at substantially the same phase. Buried in

  By the way, in such a rubber-coated member, when used in a tire, in order to exert a desired function and impart desired performance to the tire, the wavelength of the wavy cord is a predetermined wavelength. It is necessary to adapt the wavy code to a predetermined standard (standard) such as (wavelength range). For this reason, for example, when the rubber-coated member is manufactured, the wavelength of the wavy cord is formed in a predetermined wavelength range and supplied to the green tire molding process, and the wavelength of the wavy cord satisfies a predetermined standard. Regarding the wavelength of the wavy cord, such as being wound around a tire, a standard is usually defined at each stage (process).

  Specifically, for example, in a rubber-coated member used in an APR tire (aircraft radial tire), the length of the four wavelengths of the wavy cord is 106 ± 4 mm before being supplied to the green tire molding process, In addition, the standard stipulates that it is 112 mm or less even after being wound around a raw tire and stretched, and the wavelength of the wavy cord is measured at each step to check whether it is within this standard. .

  However, conventionally, the wavelength of the wavy cord is measured by an operator or a molder using a measure or various measuring jigs to measure the irregularities corresponding to the wavy cord formed on the surface of the rubber-coated member. In many cases, it is carried out manually, requiring a lot of labor, time, and man-hours. For this reason, conventionally, the efficiency of the inspection of the rubber-coated member (corrugated cord) is low, and accordingly, there is a problem in that the productivity of manufacturing the rubber-coated member and molding of the raw tire is lowered. Also, because it is a manual measurement, there is a possibility that a wavelength measurement error may occur, and there is a possibility that a defective product such as a rubber-coated member or a raw tire having a non-standard wavy cord may be sent to the next process by mistake. There are also problems with quality control in each process.

  In particular, in the example of the APR tire described above, for example, in the green tire molding process, the length of four wavelengths of the wavy cord may be 110 mm, which is the standard maximum wavelength. In this case, molding is performed. Since only 2 mm of elongation is allowed at the time (at the time of winding), more accuracy is required for wavelength measurement before and after winding (particularly after winding). As a result, it is necessary to carefully and carefully measure the wavelength of the wavy cord, and the above-described inspection efficiency and productivity are further lowered, and quality control is further important.

JP 2000-52711 A JP 2006-159691 A

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to automatically inspect the wavelength of a wavy cord in a rubber-coated member formed by coating a wavy cord with rubber. It is to improve the efficiency and accuracy of inspections while appropriately performing quality control.

According to the first aspect of the present invention, a corrugated cord that extends in a corrugated shape along the longitudinal direction is coated with rubber, and the wavelength of the corrugated cord in a rubber-coated member in which irregularities corresponding to the corrugated cord are formed on the surface is checked. A method for inspecting a cord, the step of irradiating the surface of the rubber-coated member with light to form light and dark according to the irregularities on the surface of the rubber-coated member, and an image of the surface of the rubber-coated member on which the light and dark are formed A step of acquiring density information from the acquired image, and a step of determining whether or not the wavelength of the wavy code is within a predetermined standard based on the density information. It is characterized by.
According to a second aspect of the present invention, in the method for inspecting a wavy cord according to the first aspect, the step of acquiring the image includes a step of imaging the surface of the rubber covering member on which the light and darkness is formed, and the captured image. And a step of extracting the bright and dark light portions.
According to a third aspect of the present invention, in the method for inspecting a wavy code according to the first or second aspect, the step of obtaining the density information is performed for each predetermined unit region that partially overlaps or is adjacent to the image from the image. A step of sequentially calculating an average density of pixels included in the unit area, and a difference between a maximum value and a minimum value of the average density of the pixels in the plurality of unit areas partially overlapping or adjacent to each other. A step of sequentially calculating over the entire predetermined inspection range, and comparing each calculated value of the difference with a preset threshold value of the difference, and calculating the difference value exceeding the threshold value And the step of determining compares the measured value of the count number with a minimum value and / or maximum value of the count number set in advance corresponding to the predetermined standard. Based on the comparison result And performing serial determination.
According to a fourth aspect of the present invention, in the wavy code inspection method according to the third aspect, in the step of sequentially calculating the average density of the pixels, the unit area is arranged along the longitudinal direction of the wavy code in the image. The step of calculating the average density while moving by a predetermined number of pixels and calculating the difference calculates the difference in the plurality of unit regions partially overlapping or adjacent to each other in the moving direction of the unit region. It is characterized by that.
According to the invention of claim 5, a wavy cord that extends in a wavy shape along the longitudinal direction is coated with rubber, and the wavelength of the wavy cord in a rubber-coated member in which irregularities corresponding to the wavy cord are formed on the surface is checked. A code inspection apparatus, which irradiates light on the surface of the rubber-coated member to form light and dark according to the unevenness on the surface of the rubber-coated member, and images the surface of the rubber-coated member on which the light and darkness is formed Imaging means for acquiring, density information from the captured image, and analysis means for determining whether or not the wavelength of the wavy code is within a predetermined standard based on the density information. Features.
According to a sixth aspect of the present invention, in the wavy cord inspection apparatus according to the fifth aspect, the imaging means and the light source are moved to maintain a predetermined distance from the surface of the rubber covering member to be imaged. A moving means is provided.
A seventh aspect of the present invention is the inspection apparatus for a wavy code according to the fifth or sixth aspect, wherein the analysis unit includes an extraction unit that extracts the bright and dark bright parts from the captured image. Is density information based on an image obtained by extracting the bright part.
According to an eighth aspect of the present invention, in the wavy code inspection apparatus according to any one of the fifth to seventh aspects, the analysis unit is configured to detect, from the image, a predetermined unit region that partially overlaps or is adjacent to the image. Average density calculation means for sequentially calculating the average density of the pixels included in the unit area, and the difference between the maximum value and the minimum value of the average density of the pixels in the plurality of unit areas partially overlapping or adjacent to each other. The difference calculation means for calculating sequentially over the entire image or a predetermined inspection range, the difference between the calculated value of the difference and a preset threshold value of the difference, and the difference exceeding the threshold value A counting means for counting the number of calculated values, and an actual value of the counting number by the counting means and a minimum value and / or a maximum value of the counting number set in advance corresponding to the predetermined standard, The comparison It characterized by having a a determination means makes the determination based on the result.
According to a ninth aspect of the present invention, in the wavy code inspection apparatus according to the eighth aspect, the average density calculating means includes a predetermined number of pixels along the longitudinal direction of the wavy code in the unit area in the image. The average density is calculated while being moved one by one, and the difference calculating means calculates the difference in the plurality of unit areas that partially overlap or are adjacent to each other in the moving direction of the unit area.

  According to the present invention, the wavelength of a wavy cord in a rubber-coated member formed by coating a wavy cord with rubber can be automatically inspected, and quality control can be performed appropriately, and the efficiency and accuracy of inspection are improved. be able to.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The corrugated cord inspection apparatus of the present embodiment is an apparatus for inspecting a rubber-coated member in which one or a plurality of corrugated cords are arranged and covered with rubber, which is used, for example, in the corrugated belt layer of the tire described above. Then, it is inspected whether or not the wavelength of the wavy cord embedded therein is within a predetermined standard. Further, this inspection device is installed, for example, adjacent to a rubber covering member conveyance path, a raw tire molding device, or the like, and automatically inspects a rubber covering member being conveyed or wound around the raw tire.

  The surface of the rubber covering member to be inspected has a relatively thick portion (convex portion) and a relatively thin portion (concave portion) between the corrugated cord and the rubber covering member. The corrugation corresponding to the corrugated cord is formed, for example, along the longitudinal direction (length direction), and the inspection apparatus of this embodiment uses the corrugation on the surface to adjust the wavelength of the corrugated cord. inspect. Further, in the present embodiment, a rubber coated member in which a plurality of wavy cords extending while being curved in a substantially sine wave shape along the longitudinal direction are arranged at substantially the same phase and covered with rubber will be described as an example.

  FIG. 1 is a main part configuration diagram schematically showing a schematic configuration of a corrugated cord inspection apparatus 1 of the present embodiment together with a rubber coating member 70, and in the drawing, a part including the rubber coating member 70 is a perspective view. Show. In addition, an arrow N in the figure is the longitudinal direction of the rubber covering member 70 and each corrugated cord therein, and an arrow H orthogonal thereto is the width direction of the rubber covering member 70. Accordingly, each wavy cord extends in a wavy shape along the arrow N direction in the figure, and a plurality of wavy cords are arranged in the arrow H direction in the figure.

  As shown in the figure, the inspection apparatus 1 is connected to the light source 10 and the imaging means 20 disposed on one side (upper side in the drawing) of the rubber covering member 70 and to each part of the apparatus including them, and controls the entire inspection apparatus 1. And a control analysis device 30 that performs image analysis and the like.

  The light source 10 is for irradiating a predetermined position on the surface of the rubber covering member 70 to form light and dark according to the unevenness by the wavy cord on the surface. For example, various light sources such as a rod-shaped lamp and a fluorescent lamp are used. It is an illumination (light projection) device using an electric lamp or a light emitting diode (LED). The light source 10 is provided at a position shifted in the width direction H of the rubber covering member 70 with respect to the imaging unit 20, and the light emitting surface 11 is disposed toward the imaging range K by the imaging unit 20. The whole is illuminated by irradiating light from the upper side (arrow S in the figure) toward K. As a result, the light source 10 irradiates light on the irregularities on the surface of the rubber covering member 70 from obliquely above the direction (amplitude direction) (arrow H in the figure) substantially orthogonal to the longitudinal direction of the wavy cord, The portion is mainly illuminated to make a shadow in the concave portion, and the corresponding light and darkness is formed over the entire imaging range K to emphasize the unevenness of the surface.

  Here, the position of the light source 10, the light irradiation angle, and the like are set according to each situation such as the degree of unevenness so that light and darkness corresponding to the unevenness is likely to occur on the surface of the rubber covering member 70. Similarly, the light source 10 is used in which the brightness and darkness corresponding to the unevenness becomes clear according to the surface properties such as the color of the surface of the rubber covering member 70 and each characteristic, for example, white light by a fluorescent lamp, A light emitting diode that generates light of each color, an infrared ray, an ultraviolet lamp, or the like is appropriately selected. In this embodiment, the rubber covering member 70 to be inspected is covered with the rubber used for the tire, and the surface thereof has a black luster, so that a blue light emitting diode that generates blue light is used as the light source 10.

FIG. 2 is an example showing a state in which the surface of the rubber covering member 70 is illuminated by two types of light sources 10, FIG. 2A shows a case where a fluorescent lamp is used as the light source 10, and FIG. The ones using are shown respectively.
As shown in the drawing, both light sources 10 can form wavy light and darkness (bright portion 71 and dark portion 72) corresponding to the unevenness by the wavy cord on the surface of the rubber covering member 70, but white light from a fluorescent lamp (see FIG. 2A). ), The difference between the bright portion 71 and the dark portion 72 is unclear, and the light and dark according to the unevenness is unclear. On the other hand, in the blue light (refer FIG. 2B) by the blue light emitting diode of this embodiment, the difference between the bright part 71 and the dark part 72 is clear, and the light and dark according to the unevenness | corrugation can be identified more clearly.

  The imaging means 20 (see FIG. 1) images the imaging range K (inspection range) on the surface of the rubber covering member 70 on which the light and darkness is formed, and outputs the image to the control analysis device 30. The imaging means 20 is, for example, a CCD (Charge Coupled Device) camera or a CMOS camera using a CMOS (Complementary Metal Oxide Semiconductor) image sensor. In this embodiment, the imaging means 20 has a predetermined number of pixels (for example, 2 million pixels). ) Black and white CCD camera. Further, a lens, a close-up ring, or the like is attached to the tip (bottom end in the figure) on the rubber covering member 70 side, and images of the imaging range K are taken continuously or every predetermined time. Is converted into an electrical signal, and image data such as light and dark density (luminance) for each pixel is output to the control analyzer 30.

  The control analysis device 30 controls the entire inspection device 1 and inspects the wavelength of the wavy cord in the rubber covering member 70. For example, the central processing unit performs various data processing, analysis, arithmetic processing, and the like. (CPU), a ROM that stores various programs, a RAM that stores temporary data for processing, a storage unit such as a hard disk drive, and a personal computer that includes a monitor. The control analysis device 30 is connected to each part of the device such as the light source 10 and the imaging means 20 via an interface, etc., and transmits / receives various data necessary for inspection to / from them to perform predetermined image analysis and inspection. Execute processing etc. That is, the control analysis device 30 acquires and analyzes an image of the imaging range K (inspection range) imaged by the imaging unit 20 and determines whether or not the wavelength of the wavy cord in the rubber covering member 70 is within a predetermined standard. In the following, each process performed by the control analysis device 30 will be described.

FIG. 3 is a functional block diagram of the control analysis device 30, and other configurations of the inspection device 1 are also shown in blocks.
The control analysis device 30 includes an input / output unit 31, a display unit 32, a storage unit 33, a control unit 34, and an image analysis unit 35 to which external devices are connected. 35 are connected to each other via a bus 36.

  The input / output unit 31 is connected to the light source 10 and the imaging unit 20 via, for example, a controller or a sequencer that is a control unit for controlling each of them, and converts various data, control signals, and the like between them and transmits and receives them. Interface. The display unit 32 is a display unit such as a monitor that displays various types of information, and displays an image captured on the surface of the rubber covering member 70, an inspection result, and the like.

  The storage unit 33 stores various programs and data necessary for control processing, determination / inspection processing, and the like of the inspection apparatus 1. The storage unit 33 also includes measurement data 33A such as a captured image obtained by the imaging unit 20, each data (inspection data 33B) relating to an inspection result analyzed and calculated by an image analysis unit 35 described later, and a rubber coating to be inspected. A predetermined standard (standard) (standard data 33C) relating to the quality of the wavelength of the wavy cord (here, the length of four wavelengths) preset for the member 70 is stored. The standard data 33C includes various preset standards such as a data table such as a maximum value or minimum value of the wavelength of the wavy code serving as a boundary between good and bad, or respective predetermined values (set values) corresponding thereto. Data is stored for each type of rubber covering member 70 to be inspected.

  The control unit 34 performs data processing, arithmetic processing, and the like related to control of the entire inspection apparatus 1 and controls the entire inspection apparatus 1, for example, irradiation of light by the light source 10, imaging by the imaging unit 20, captured images, and the like. The storage processing of the various data in the storage unit 33 is executed. Further, the control unit 34 outputs an alarm command to an alarm unit (not shown) via the input / output unit 31 in accordance with the inspection result of the wavy cord of the rubber covering member 70, and controls the alarm unit to control sound and A warning output process using light or the like is executed.

  The image analysis unit 35 is an analysis means for performing each calculation / analysis process relating to the inspection of the wavy code, such as analyzing the image of the rubber covering member 70 and determining the quality of the wavelength of the wavy code therein. A unit 35A, an average density calculation unit 35B, a difference calculation unit 35C, a count unit 35D, and a determination unit 35E. The image analysis unit 35 acquires density information from an image relating to the unevenness (brightness and darkness) of the surface of the rubber covering member 70 acquired from the imaging device 20 via the input / output unit 31, and based on this information, each unit (means) 35A to 35A to 35A. Predetermined image analysis and calculation processing is performed by 35E, the above-described determination is performed, and the result is stored in the inspection data 33B of the storage unit 33.

  The extraction unit 35A filters the image on the surface of the rubber covering member 70 by, for example, extracting pixels having a predetermined density (brightness) or more from the image captured by the image capturing unit 20, and performs the light and dark according to the unevenness. The bright part is extracted.

FIG. 4 is a diagram showing an example of images before and after extracting the bright part by the extraction unit 35A, and is an example of display on the display unit 32 of four images having different wavelengths of the wavy code. 4A to 4D show images of the rubber covering member 70 having wavy cords having lengths of four wavelengths of 108 mm, 110 mm, 112 mm, and 114 mm, respectively.
As shown in the figure, a bright portion 71 and a dark portion 72 corresponding to the shape and wavelength of each wavy cord are imaged in the captured image 80 of the rubber covering member 70 by the imaging means 20. In the bright portion extraction image 81 (rectangular image shown in the lower part of each figure) in a predetermined inspection range obtained by performing extraction processing on the captured image 80 by the extraction unit 35A, the density is equal to or higher than the predetermined density of the bright portion 71. A portion (pixel) is extracted, and the entire screen is displayed by an extracted bright portion 82 (white portion in the figure) having a linear shape or the like and another portion (black portion in the drawing).

  This extracted bright portion 82 appears in a form corresponding to the shape and position of the wavy code (the convex portion on the surface of the rubber covering member 70), the wavelength, the amplitude, and the like in each bright portion extracted image 81. That is, each of the extracted light portions 82 has a substantially wave-like form as a whole, but the wavelength of the wavy code is long as is apparent from the respective bright portion extracted images 81 in FIGS. 4A to 4D. The smaller the amplitude, the smaller the wavy degree of each extracted bright part 82. As a result, each of the extracted light portions 82 gradually becomes closer to a straight line as the wave-like code is stretched to increase the wavelength and the amplitude becomes smaller, and finally the wave-like code is stretched linearly. Are arranged in a straight line.

  The image analysis unit 35 (see FIG. 3) of the present embodiment acquires the density information based on the image obtained by extracting the bright part 71 (bright part extraction image 81), that is, performs subsequent analysis using this image, First, the average density calculation unit 35B executes a process for calculating the average density of pixels in the area, with a plurality of adjacent pixels as one unit.

  Specifically, the average density calculation unit 35B sets a unit area (segment) composed of a predetermined number of pixels for the acquired image, and calculates the average of the pixels in the unit area from the density of each pixel included therein. After the density is calculated, the unit areas are moved in a predetermined direction so as to partially overlap or adjoin each other, and the average density of each unit area is sequentially calculated. As described above, the average density calculation unit 35B calculates the average density of the pixels included in each unit area from the acquired image for each predetermined unit area that overlaps or is adjacent to the entire image (or the predetermined inspection range). Are calculated sequentially over the period.

  The unit area is a virtual small area, such as a rectangular shape, which is set by dividing the image (pixel) so as to include a predetermined number of pixels in each of the vertical and horizontal directions. The number of pixels) is set in advance according to the state of the image, the required inspection accuracy, and the like. Further, in this average density calculation unit 35B, the set unit region is moved from one end side to the other along the longitudinal direction of the wavy cord (left and right in FIG. 4) in the image of the rubber covering member 70 (see FIG. 4). The average density of each unit region is calculated while moving by overlapping a certain number of pixels toward the end side, or partially overlapping (here, partially overlapping), and the amplitude direction of the wavy code on the other end side ( A predetermined number of pixels are moved in the vertical direction in FIG. Similarly, the average density calculation 35B sequentially moves the unit areas in the longitudinal direction and the amplitude direction of the wavy code, and sequentially calculates the average density for each unit area.

  The difference calculating unit 35C (see FIG. 3), based on each calculated average density, maximizes the average density of each pixel in a plurality of unit areas that partially overlap or are adjacent to each other in the longitudinal direction or the amplitude direction of the wavy code. The difference between the value and the minimum value (maximum difference in average density) is calculated. The difference calculating unit 35C moves each unit region by moving one or more unit regions, for example, one by one or more along a predetermined direction such as the longitudinal direction or the amplitude direction of the wavy code. As a unit, a part thereof is moved overlapping or adjacent to each other, and each difference is sequentially calculated over the entire image or over the entire predetermined inspection range.

  In this way, the difference calculation unit 35C has a predetermined number (for which the average density has already been calculated) after the above-described average density calculation unit 35B completes the entire average density calculation process or during the calculation process in synchronization with each calculation process. The average density difference (maximum difference) calculation process is executed for the unit area of (range). Further, here, the difference calculation unit 35C includes a plurality of unit regions that partially overlap or are adjacent to each other in the direction of calculation of the average density by the average density calculation unit 35B, that is, the direction of movement of the unit regions when the average density is calculated. The difference in is calculated.

FIG. 5 is a schematic diagram for specifically explaining each calculation procedure by the above average density calculation unit 35B and difference calculation unit 35C.
As shown in the figure, the average density calculation unit 35B of the present embodiment converts a unit region T composed of a predetermined number of pixels having a predetermined size into a predetermined movement amount (here, 1/3 of the unit region T). The average density of the pixels in each unit region T is calculated while shifting each side of the wavy code along the longitudinal direction (left and right direction in the figure) to one side (arrow in the figure). In this way, the unit region T1 (average density 95) (see FIG. 5A), unit region T2 (average density 80) (see FIG. 5B), unit region T3 (average density 100) (see FIG. 5C), unit The area T4 (average density 120) (see FIG. 5D) and the average density of the four unit areas T1 to T4 are calculated.

  Based on the calculation results, the difference calculation unit 35C determines the maximum value of the average density in the four unit regions T1 to T4 partially overlapping each other in the moving direction (120 in the unit region T4 shown in FIG. 5D here). ) And the minimum value (here, 80 of the unit region T2 shown in FIG. 5B) (here, 40). In this manner, each of the calculation units 35B and 35C calculates the average density by moving the unit region T, and sequentially calculates the differences of the four unit regions T that have already been partially overlapped.

  The counting unit 35D (see FIG. 3) compares each calculated value of the difference with a threshold value of a predetermined difference, and counts the number of calculated values of the difference exceeding the threshold value. The threshold value of the difference is a preset minimum value that is recognized as an effective density difference. For example, the difference threshold value is experimentally determined for each rubber covering member 70 to be inspected, or the above-described bright portion extraction image. 81 (see FIG. 4) is determined in accordance with aspects such as the density and size of each of the extracted bright portions 82, the inspection conditions such as the size and movement amount of the unit area, and the storage unit 33 (see FIG. 3). ) Standard data 33C. The count unit 35D reads this threshold value from the standard data 33C, and performs the above-described count every time each difference is calculated by the difference calculation unit 35C or after all the differences are calculated, and calculates the difference exceeding the threshold value. Add the number of values to find the total number (count).

  Here, in this embodiment, the difference in the average density of the plurality of unit regions is calculated along the longitudinal direction of the wavy cord (see FIG. 4). The difference in the average density between the unit regions in the longitudinal direction is The larger the angle of inclination (degree of undulation) of each part that is inclined with respect to the longitudinal direction of the undulating cord, the larger the value. Therefore, the difference calculation value by the difference calculation unit 35C is larger as the wavy cord has a larger wave shape and a shorter wavelength, and the rubber covering member 70 and the wavy cord are stretched to increase the wavelength and gradually become closer to a straight line. Becomes smaller. Thus, the calculated value of the difference changes according to the change in the wavelength of the wavy cord, and finally, in the linear wavy cord, the average density difference in the longitudinal direction disappears theoretically to a value close to zero. Become. As a result, the total number of difference calculated values exceeding the threshold value, that is, the count number by the counting unit 35D also changes according to the wavelength of the wavy code. , The longer it is, the less it is.

  FIG. 6 is a diagram (graph) showing the relationship between the actually measured value of the count number and the wavelength of the wavy code (here, the length of four wavelengths), and the wavelengths of the wavy codes shown in FIGS. 4A to 4D are different. An example in which two images are analyzed as described above and each numerical value of the analysis result is graphed is shown. In addition, the horizontal axis of the figure represents the four-wavelength length (mm) of the wavy code, and the vertical axis represents the actual count value.

  As shown in the figure, the actually measured values of the count numbers are located on substantially the same straight line with a negative slope (lower right in the figure), and become smaller in proportion to the length of four wavelengths. Thus, there is a correlation between the number of counts and the length of four wavelengths, and in the inspection apparatus 1 of this embodiment, the wavelength of the wavy cord in the rubber covering member 70 is determined by using this. It is determined by the determination unit 35E (see FIG. 3) whether or not it satisfies a predetermined standard, such as whether it is within the specified range, whether it is less than the maximum allowable wavelength, or whether it is greater than or equal to the minimum value. And inspect.

  That is, the determination unit 35E compares the actually measured value of the count number (total number) by the count unit 35D with the minimum value and / or maximum value of the count number set in advance corresponding to a predetermined standard of the wavy code, Based on the comparison result, it is determined whether or not the wavelength of the wavy code is within a predetermined standard. Specifically, in the example of the graph shown in FIG. 6, for example, when it is determined that the four-wavelength length of the wavy code is 112 mm or less, the minimum value (lower limit value) of the corresponding count number is When the actual count value is greater than 2000, the determination unit 35E determines that the 4-wavelength length is 112 mm or less and within the standard, and when 2000 or less, the wavelength is longer than 112 mm. It is determined that it is outside. Similarly, the determination unit 35E determines, for example, that the maximum value (upper limit value) 3000 of the corresponding count number is compared with the actually measured value of the count number when the standard of the four wavelength length is 108 mm or more. I do. Further, the determination unit 35E compares the minimum value and the maximum value of the count number corresponding to the upper and lower limit values with the actually measured value of the count number when a predetermined range is defined with respect to the four-wavelength length standard. Whether or not the wavelength of the wavy code is within the standard is determined based on whether or not the actually measured value is between the minimum value and the maximum value.

  Note that the minimum value and the maximum value of these count numbers are actually measured with respect to the rubber covering member 70 having a plurality of wavy cords having different wavelengths as described above, and the respective count values (see FIG. 6) are measured. Obtain a value corresponding to the wavelength standard, or experimentally obtain and set, for example, by actually measuring the number of counts of the rubber covering member 70 having the wavy cord having the same wavelength as the wavelength standard value (upper limit value or lower limit value). Is done. The set minimum and maximum values are stored in advance in the standard data 33C of the storage unit 33 (see FIG. 3), and read and used by the determination unit 35E of the image analysis unit 35 at the time of inspection.

  Next, procedures and operations for inspecting the wavelength of the wavy cord in the rubber covering member 70 using the inspection apparatus 1 described above will be described. The following procedures and the like are controlled by the control analysis apparatus 30 to be performed in a predetermined manner. Based on a program, preset conditions, and the like, each part of the apparatus is operated at a predetermined timing and is operated in conjunction with each other.

  At the time of inspection, first, light is irradiated to a predetermined inspection position (imaging range K) on the surface of the rubber covering member 70 by the light source 10 (see FIG. 1), and light and darkness corresponding to the unevenness by the wavy cord is applied to the surface of the rubber covering member 70 The imaging range K of the surface of the rubber covering member 70 formed and imaged is captured by the imaging means 20 to obtain an image. Subsequently, the acquired image is subjected to image analysis as described above by the image analysis unit 35 of the control analysis device 30, and predetermined density information is acquired from the image. The inspection apparatus 1 determines whether or not the wavelength of the wavy code is within a predetermined standard based on the concentration information.

  Specifically, first, the light-and-bright bright part 71 is extracted from the image 80 (see FIG. 4) captured on the surface of the rubber covering member 70 by the extraction part 35A of the image analysis part 35. Next, the average density calculation unit 35B performs, for each predetermined unit region T (see FIG. 5) that partially overlaps or adjoins (here, overlaps) in the image, for each predetermined unit region T (see FIG. 5). The average density of all the pixels included in the unit region T is sequentially calculated. Further, the difference calculation unit 35C sequentially calculates the difference between the maximum value and the minimum value of the average density of the pixels in the plurality of unit regions T partially overlapping or adjacent to each other over the entire image (or a predetermined inspection range). calculate. At the time of each of these calculations, the inspection apparatus 1 calculates the average density while moving the unit region T by a predetermined number of pixels along the longitudinal direction of the wavy code, and partially in the moving direction of the unit region T. Differences in a plurality of overlapping unit regions T (four unit regions T1 to T4 in the example shown in FIG. 5) are calculated.

  Next, the count unit 35D compares each calculated value of the average density difference with a preset difference threshold value, and counts the number of calculated difference values exceeding the threshold value. Thereafter, the determination unit 35E compares the actual value of the count number (total number) with the minimum value and / or maximum value of the count number set in advance corresponding to the predetermined standard, and based on the comparison result. It is determined whether the wavelength of the wavy code is within the standard and conforms to the standard.

  The inspection apparatus 1 automatically and repeatedly repeats the inspection of the wavy cord continuously or at predetermined time intervals or at predetermined timings with respect to a rubber covering member or the like being conveyed or wound around a raw tire. Execute. Further, the inspection device 1 stores each data related to the inspection such as the results of each analysis and calculation by the image analysis unit 35 (see FIG. 3) or the determination results and the inspection results in association with the inspected rubber covering member 70. 33 inspection data 33B.

  As described above, according to the present embodiment, whether or not the wavelength of the wavy cord in the rubber covering member 70 is within the standard can be automatically inspected without human intervention. The labor and time required, and the number of man-hours can be greatly reduced. As a result, the efficiency of the wavelength inspection is improved, the productivity of manufacturing the rubber-coated member 70 and the molding of the raw tire can be improved, and the occurrence of errors in the measurement and inspection of the wavy cord wavelength is suppressed. Therefore, the accuracy of the inspection can be improved. At the same time, it is possible to prevent defective products such as rubber-coated members and raw tires with non-standard wavy cords from being sent to the next process by mistake, and to store and manage inspection history and inspection results as images and numerical data. Therefore, it is possible to easily and appropriately perform quality control and countermeasures when defective products occur.

  Here, in this embodiment, the image analysis is performed based on the image (the bright part extracted image 81) (see FIG. 4) from which the bright part 71 is extracted. You may perform based on the captured image 80. FIG. However, when the bright portion extraction image 81 is image-analyzed as in the inspection apparatus 1, the brightness and darkness of the image can be clearly identified, and the subsequent analysis processing and inspection can be performed more accurately and accurately. More desirable. In addition, the image to be analyzed may be the entire range of the image captured by the imaging unit 20, or may be an image obtained by extracting a predetermined region (inspection range) therefrom.

  On the other hand, the moving direction of the unit area by the average density calculating unit 35B and the calculating direction of the difference by the difference calculating unit 35C are also moved substantially along the longitudinal direction, for example, inclined at a certain angle with respect to the longitudinal direction of the wavy cord. Therefore, the direction may be other than the longitudinal direction of the wavy cord. In each of these calculation procedures, the average density may be calculated while moving the unit area, and the difference in the moving direction may be calculated at the same time. The average density of the predetermined range or all the unit areas of the calculation target image may be calculated. Each difference may be calculated after the calculation. As described above, each calculation procedure depends on each inspection mode, such as the target image, the size (number of pixels) of the unit area, the amount of movement of the unit area, and the total calculation amount required for the calculation. Is set as appropriate.

  Further, the difference calculation by the difference calculation unit 35C is performed on a predetermined number of unit areas in a two-dimensional direction including a direction orthogonal to the moving direction, for example, other than a predetermined number of unit areas in the moving direction (one-dimensional direction) of the unit area. For example, it may be performed for a plurality of unit areas in another predetermined range set in advance. In addition, here, the determination unit 35E compares the actual count value of the count unit 35D with each set value. However, based on the actual count value and the relational expression of the wavelength, etc., The wavelength of the wavy code may be calculated, and the calculated value may be compared with the wavelength standard to determine whether the standard is satisfied.

  In addition, according to the present embodiment, as the rubber covering member 70, in addition to the above-described corrugated belt layer, other rubber covering members in which corrugated cords are disposed, for example, a reinforcing layer disposed in a tire side portion, a bead portion, or the like. 70 can also be inspected. Further, in the present embodiment, the description has been given by taking a substantially sinusoidal wavy cord as an example. Other shapes extending in a wave shape along the longitudinal direction, such as a wave shape extending while being bent such as a triangular wave shape (zigzag shape), or a wave shape obtained by arbitrarily combining them may be used. Therefore, the wavy cord of the present invention includes various wavy cords that are regularly oscillated in this manner and extend in a wavy shape in various forms along the longitudinal direction.

  Further, the corrugated cord in the rubber covering member 70 is corrugated regardless of the material or type, such as a cord made of metal such as steel or a cord made of organic fiber such as Kevlar fiber. Any member that forms irregularities on the surface may be used.

Next, specific examples in which the inspection apparatus 1 described above is incorporated on-line (on the production line) and applied to various processes will be described.
FIG. 7 is a side view schematically showing an example in which the inspection apparatus 1 of the present embodiment is applied to a green tire molding process, and FIG. 8 is a schematic diagram showing the vicinity of the inspection apparatus 1 shown in FIG. is there.

  In the green tire molding process, as shown in FIG. 7, a substantially cylindrical molding drum 40 rotatable around an axis is rotated by a driving means (not shown) such as a motor, and the outer surface has a predetermined dimension. Each tire constituent member such as an inner liner, a carcass, and a rubber covering member 70 is wound to form the raw tire 41. The inspection device 1 is installed on the outside in the radial direction of the molding drum 40 and the green tire 41 in the middle of molding, and the imaging means 20 and the light source 10 face the molding drum 40 side and face the outer surface thereof. Be placed. From that position, the inspection apparatus 1 irradiates light toward a predetermined position of the rubber covering member 70 wound around the outer surface of the lower tire constituent member, and takes an image of the surface at a predetermined timing as described above. Image analysis or the like is performed, and the wavelength of the wavy cord in the rubber covering member 70 is inspected online. In addition, the inspection apparatus 1 performs the wavelength inspection once after the rubber covering member 70 is wound, or at a plurality of locations in the circumferential direction of the rubber covering member 70 by rotating the molding drum 40. Execute every molding.

  Here, in order to prevent fluctuations in the inspection results for each inspection and to perform appropriate inspection continuously, the distance between the imaging means 20 and the light source 10 and the surface of the rubber covering member 70 to be imaged is set. Even if the outer diameter of the raw tire 41 changes, it is necessary to maintain a predetermined distance that allows appropriate imaging and inspection. Therefore, as shown in FIG. 8, the inspection apparatus 1 includes moving means 42 and 45 that move the imaging means 20 and the light source 10 toward and away from the molding drum 40 (rubber covering member 70). The inspection apparatus 1 uses the moving means 42 and 45 to move the imaging means 20 and the light source 10 together to maintain the distance between the surface of the rubber covering member 70 to be imaged and keep the imaging and inspection conditions constant. It is designed to maintain the conditions.

  As the moving means 42 and 45, for example, a pneumatic or hydraulic piston / cylinder mechanism, a linear movement mechanism including a rack, pinion, and a stepping motor, or a screw action including a ball screw or a ball spline is used. Well-known means such as a linear movement mechanism for movement can be used.

  When a piston / cylinder mechanism is used as the moving means 42 (see FIG. 8A), the imaging means 20 and the light source 10 are attached to the piston rod 43P, and a rotatable substantially cylindrical roll 44 is attached to the tip thereof. The rod 43P is taken in and out of the cylinder 43S, and the imaging means 20 and the light source 10 are moved closer to and away from the rubber covering member 70. Further, here, a predetermined pressure is applied to the cylinder 43S so that the outer surface of the roll 44 is brought into contact with the surface of the rubber covering member 70, and the roll 44 is urged toward the rubber covering member 70 with a predetermined pressure. The roll 44 and the piston rod 43P are displaced in conjunction with the change in the outer diameter of the covering member 70. Accordingly, the moving unit 42 maintains a predetermined distance between the imaging unit 20 and the light source 10 and the surface of the rubber covering member 70.

  On the other hand, when the above-described linear moving mechanism is used as the moving unit 45 (see FIG. 8B), the imaging unit 20 and the light source 10 are moved by a rack, a ball spline, or the like that extends linearly toward the rubber covering member 70. The member 45A is attached to the rubber covering member 70 side. In the moving means 45, a distance sensor (not shown) detects the distance to the surface of the rubber covering member 70, and moves the moving member 45A based on the detection result, thereby the imaging means 20 and the light source 10 A predetermined distance from the surface of the rubber covering member 70 is maintained.

  The example in which the inspection device 1 is applied to the molding process of the raw tire 41 (new tire) has been described above. However, the inspection device 1 can also be used in the molding process of the corrected tire. That is, in the molding process of the corrected tire, after removing the tread rubber and each belt layer of the used tire, it is necessary to newly wind the rubber covering member 70 (the corrugated belt layer). At that time, the wavelength of the wavy cord in the rubber covering member 70 may be similarly inspected by the inspection device 1.

The inspection apparatus 1 can also be applied to the manufacturing process of the rubber covering member 70 and the like.
FIG. 9 is a schematic diagram illustrating an example in which the inspection apparatus 1 is installed in the conveyance path of the rubber covering member 70.

  Here, as shown in the figure, after the rubber covering member 70 is manufactured, it is placed on the conveying means 50 such as a conveyor and conveyed toward the take-up roll, the next process, etc. (arrow N in the figure). . The inspection device 1 is installed above the conveying unit 50 at a predetermined distance, and the imaging unit 20 and the light source 10 are arranged facing the rubber covering member 70. From that position, the inspection apparatus 1 irradiates light toward a predetermined position on the surface of the rubber covering member 70, and images the surface continuously or every predetermined time. The wavelength of the wavy cord in 70 is inspected online.

  In this case, since the distance between the imaging means 20 and the light source 10 and the surface of the rubber covering member 70 is constant, the moving means 42 and 45 are not provided as in the molding process of the raw tire 41 described above. However, the imaging and inspection conditions are kept constant.

(Wavelength inspection test)
In order to confirm the effect of the present invention, the inspection apparatus 1 described above performs a wavelength inspection of the wavy cord in the rubber covering member 70 to test whether the inspection can be performed correctly. In the test, the rubber-coated member 70 in which a plurality of wavy cords were arranged was inspected, and the quality of the four-wavelength length of the wavy cords was determined to be 112 mm or less to determine pass / fail. That is, it was determined that the actual value of the count number by the counting unit 35D is larger than 2000 (see FIG. 6) is within the standard, and the actual value of 2000 or less is out of the standard.

  As a result, as shown in the upper left and upper right of each image example of FIG. 4 already described, the four-wavelength length of the wavy code is 112 mm or less (108 mm in FIG. 4A, 110 mm in FIG. 4B, 112 mm in FIG. 4C). The measured value of the count number was larger than 2000 (3101, 2807, 2180, respectively), and determined to be within the standard (OK). On the other hand, when the length of the four wavelengths is longer than 112 mm (114 mm in FIG. 4D), the measured value of the count number is 1262 of 2000 or less, and it was determined to be nonstandard (NG). From this, it was found that the wavelength of the wavy cord in the rubber covering member 70 can be correctly inspected by the inspection device 1.

  From the above results, according to the present invention, the wavelength of the wavy cord in the rubber covering member 70 formed by covering the wavy cord with rubber can be automatically inspected, and the quality control can be appropriately performed, and the efficiency and accuracy of the inspection can be improved. Proven to improve

It is a principal part block diagram which shows typically schematic structure of the inspection apparatus of the wavy cord of this embodiment with a rubber coating | coated member. It is an example (photograph) which shows the state which illuminated the surface of the rubber coating member of this embodiment with two types of light sources. It is a functional block diagram of the control analysis apparatus of this embodiment. It is a figure which shows the example of an image before and after extracting a bright part from a captured image. It is a schematic diagram for demonstrating concretely about each calculation procedure by an average density | concentration calculation part and a difference calculation part. It is a diagram which shows the relationship between the measured value of a count number, and the wavelength (length of 4 wavelengths) of a wavy code. It is a side view which shows typically the example which applied the inspection device of this embodiment to the fabrication process of a green tire. It is a schematic diagram which extracts and shows the vicinity of the inspection apparatus shown in FIG. It is a schematic diagram which shows the example which installed the inspection apparatus of this embodiment in the conveyance path | route of a rubber coating member.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wavy code inspection apparatus, 10 ... Light source, 11 ... Light emission surface, 20 ... Imaging means, 30 ... Control analysis apparatus, 31 ... Input / output part, 32 ... Display unit 33 ... Storage unit 33A ... Measurement data 33B ... Inspection data 33C ... Standard data 34 ... Control unit 35 ... Image analysis unit 35A ... Extraction unit, 35B ... average density calculation unit, 35C ... difference calculation unit, 35D ... count unit, 35E ... determination unit, 36 ... bus, 40 ... molding drum, 41 ... · Raw tire, 42 ... moving means, 43P ... piston rod, 43S ... cylinder, 44 ... roll, 45 ... moving means, 45A ... moving member, 50 ... conveying means 70 ... rubber covering member, 71 ... bright part, 72 ... dark part, 80 ... Image image, 81 ... light portion extracted image, 82 ... extraction bright part.

Claims (9)

A wavy cord inspection method for inspecting the wavelength of a wavy cord in a rubber-coated member in which a wavy cord extending in a wavy shape along a longitudinal direction is covered with rubber, and a surface corresponding to the corrugated cord is formed on the surface. ,
Irradiating the surface of the rubber-coated member with light to form light and dark according to the irregularities on the surface of the rubber-coated member;
Obtaining an image of the surface of the rubber-coated member on which the brightness is formed; and
Acquiring density information from the acquired image;
Determining whether the wavelength of the wavy code is within a predetermined standard based on the concentration information;
A method for inspecting a wavy cord, comprising: In the inspection method of a wavy cord according to claim 1,
The step of acquiring the image includes a step of imaging the surface of the rubber-coated member on which the light and darkness is formed, and a step of extracting the light and dark bright portions from the captured image. Inspection method. The method for inspecting a wavy cord according to claim 1 or 2,
The step of acquiring the density information includes a step of sequentially calculating an average density of pixels included in the unit region for each predetermined unit region that partially overlaps or is adjacent to the image from the image, and a portion that overlaps each other. Alternatively, a step of sequentially calculating a difference between the maximum value and the minimum value of the average density of the pixels in a plurality of adjacent unit regions over the entire image or a predetermined inspection range, and each calculated value of the difference in advance Comparing the set threshold value of the difference and counting the number of calculated values of the difference exceeding the threshold value, and
The determining step compares the measured value of the count number with a minimum value and / or maximum value of the count number set in advance corresponding to the predetermined standard, and performs the determination based on the comparison result. A method for inspecting a wavy cord, characterized in that: The method for inspecting a wavy cord according to claim 3,
The step of sequentially calculating the average density of the pixels calculates the average density while moving the unit area by a predetermined number of pixels along the longitudinal direction of the wavy code in the image,
The step of calculating the difference calculates the difference in the plurality of unit regions that partially overlap or are adjacent to each other in the moving direction of the unit region. An apparatus for inspecting a wavy cord, in which a wavy cord extending in a wavy shape along a longitudinal direction is coated with rubber, and the wavelength of the wavy cord in a rubber-coated member in which irregularities corresponding to the wavy cord are formed on a surface thereof ,
A light source that irradiates light on the surface of the rubber-coated member to form light and dark according to the irregularities on the surface of the rubber-coated member;
Imaging means for imaging the surface of the rubber-coated member on which the brightness is formed;
Analyzing means for acquiring density information from the captured image and determining whether the wavelength of the wavy code is within a predetermined standard based on the density information;
An inspection apparatus for wavy cords, comprising: In the inspection apparatus of the wavy cord according to claim 5,
An apparatus for inspecting a wavy cord, comprising: moving means for moving the imaging means and the light source to maintain a distance from the surface of the rubber covering member to be imaged at a predetermined distance. In the inspection apparatus of the wavy cord according to claim 5 or 6,
The analysis means includes extraction means for extracting the bright and dark bright portions from the captured image, and the density information is density information based on the image from which the bright portions are extracted. apparatus. In the inspection apparatus of the wavy cord according to any one of claims 5 to 7,
The analysis means includes an average density calculation means for sequentially calculating an average density of pixels included in the unit region for each predetermined unit region that is partially overlapped or adjacent to each other from the image, Difference calculating means for sequentially calculating the difference between the maximum value and the minimum value of the average density of the pixels in a plurality of adjacent unit regions over the entire image or a predetermined inspection range, and each calculated value of the difference Counting means for comparing the threshold value of the difference set in advance and counting the number of calculated values of the difference exceeding the threshold value, an actual value of the count number by the counting means, and the predetermined standard And a determination unit that compares the minimum value and / or the maximum value of the count number set in advance and performs the determination based on the comparison result. . The inspection apparatus for wavy cords according to claim 8,
The average density calculation means calculates the average density while moving the unit area by a predetermined number of pixels along the longitudinal direction of the wavy code in the image,
The wavy code inspection apparatus according to claim 1, wherein the difference calculation means calculates the difference in a plurality of the unit areas that partially overlap or are adjacent to each other in the moving direction of the unit area.