JP4180895B2 - Method for detecting welded part of wheel rim for automobile - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for detecting the position of a welded portion of an automobile wheel rim.
[0002]
[Prior art]
In the case of automobile wheels, a so-called two-piece type, in which a flange portion of a disk is welded to a drop portion formed on an inner peripheral surface of a wheel rim, is mainly used. In such a two-piece type automobile wheel, the wheel rim forms a cylindrical base body by welding the short sides of a substantially rectangular flat plate-like base material. The opening edge is widened and molded by pressing with a mold having a predetermined shape from both inside and outside of the cylindrical shape.
[0003]
The thus formed wheel rim is subjected to valve drilling and air leakage inspection. Here, since the valve hole is formed at a position avoiding the welded portion, and the air leak inspection is performed at the welded portion, it is necessary to clearly recognize the position of the welded portion. Therefore, as a method for detecting the welded portion of the wheel rim, conventionally, a change in the eddy current on the wheel rim surface is detected by an eddy current sensor to detect the welded portion (for example, see Patent Document 1). There have been proposed ones that detect a welded portion by imprinting a certain distance from a welding position and detecting the imprint by a vibration sensor (see, for example, Patent Document 2).
[0004]
[Patent Document 1]
JP-A-9-280805
[Patent Document 2]
Japanese Patent Laid-Open No. 11-42903
[0005]
[Problems to be solved by the invention]
However, in the above-described conventional method of detecting by an eddy current sensor, a portion with a large amount of change in eddy current on the wheel rim surface is detected as a welded portion, so that the rim surface is corrected for scratches and scratches. If there are places, the change in eddy current is large in these portions, making it difficult to detect the weld. In addition, even if vibration or the like is applied to the wheel rim during detection, the eddy current changes, so that erroneous detection is also required. On the other hand, in the above-described method of detecting a pre-engraved mark with a vibration sensor, it is difficult to detect the engraved mark when the rim surface has poor smoothness or has a flaw. There was a problem of detecting it incorrectly.
[0006]
Furthermore, in such a conventional detection method, the wheel rim is rotated, and a relatively narrow area of the surface is sequentially detected by an eddy current sensor and a vibration sensor. It is difficult to stabilize the detection level of the sensor due to the vibration generated in the above, and there is a limit to properly detecting the weld. In addition, since these sensors determine the unique location first detected on the surface of the rotating wheel rim as the welded portion position, there is a very high possibility that a flaw or the like is erroneously detected as a welded portion. There was also.
As described above, in the conventional detection method, the welded portion cannot be properly detected.
[0007]
The present invention proposes a method for detecting a welded portion of an automobile wheel rim that solves the above-mentioned problems and can appropriately detect a welded portion of a wheel rim.
[0008]
[Means for Solving the Problems]
The present invention includes an image input means for inputting image data of a projection surface of the wheel rim viewed from the opening direction, and divides the image data into a plurality of minute sections in the circumferential direction and the radial direction. The brightness of each micro-division area sequence along the radial direction is calculated by integrating the micro-division areas, and when this integrated brightness is a micro-division area array that is lower than the predetermined judgment brightness, A lightness detection process determination for determining a set of adjacent minute partition area sequences as a target part and a change amount between successive minute partition region rows in the circumferential direction are calculated from the integrated lightness, and this lightness change amount is predetermined. When the brightness change mode is changed, the change amount detection process determination for determining this as a target part, the target part determined by the lightness detection process determination, and the target part determined by the change amount detection process determination Also applies A weld detection method of the vehicle wheel rim, characterized in that it comprises a weld detection means comprises a welded portion detection process determination determines the position of the weld (claim 1). Here, the projection surface projected from the opening direction of the wheel rim is a surface projected from the upper or lower predetermined position along the substantially central axis of the wheel rim while looking for the opening of the wheel rim. For this reason, the surface closer to the surface perpendicular to the central axis of the wheel rim is projected according to the shape of the entity.
[0009]
Generally, when a metal such as steel is subjected to heat from welding, the welded portion is oxidized, so that it is difficult to reflect light and darkens compared to other portions. In addition, since the welded portion exists along the shape of the wheel rim in the axial direction, the projected surface projected from the opening direction is projected along the radial direction. In such a configuration, it is a method of detecting the welded portion using the difference in brightness between such a welded portion and the other portions, and the target part specified from the brightness by the brightness detection processing determination, A part corresponding to any of the target parts specified from the change in brightness by the change amount detection process determination is detected as a welded portion.
[0010]
Here, the brightness of the wheel rim is obtained by virtually dividing the image data of the projection plane input by the image input means into fine compartments, detecting the brightness for each fine compartment, and then calculating the brightness in the radial direction. The integrated brightness of the micro-division area sequence is calculated by integrating the values along the circle and detected as a brightness distribution along the circumferential direction (see FIG. 6). In the image data of the projection plane divided into these minute sections, the wheel rim projected on the projection plane was projected in a plane that is relatively perpendicular to the axial direction and with a relatively wide width in the radial direction. A surface or the like is preferably used. Further, the projection surface may be set in any of the opening direction on the design surface side of the wheel and the opening direction on the back surface side.
[0011]
In addition, as the lightness detection processing determination, a minute partition region row in which the integrated lightness becomes lower than a predetermined determination lightness set as a reference for the lightness of a welded portion is selected, and Is detected as a target portion having a high possibility of being a welded portion. Here, since the target region is a set adjacent to each other, when it is determined that a plurality of spaced apart micro-division region rows are each low by the determination lightness, each is recognized as an independent target region; Become. In this lightness detection process determination, since a portion brighter than the determined lightness is not specified as the target lightness, the welded portion can be reliably determined, and a high lightness portion due to reflected light or the like is erroneous. Can be prevented. However, there is a possibility of detecting a site where dirt or the like is attached.
[0012]
Furthermore, as the change amount detection process determination, a part where the change amount of lightness between successive minute partition regions is in a predetermined lightness change form is detected as the target lightness. Here, the lightness change mode in the welded portion decreases sharply toward the minus side (darkening direction) at a relatively narrow interval in the circumferential direction, and then increases toward the plus side (lightening direction). It becomes the form which decreases (refer FIG. 7). Therefore, it is possible to specify the site | part used as such a brightness change form as a site | part which is a welding part. For dirt and scratches, the brightness change amount decreases or increases relatively slowly, or changes in the circumferential direction at a wide interval. Therefore, the dirt and scratches are detected erroneously. This can be prevented by this change amount detection process determination. Here, the amount of change between the small partition region rows may be obtained by calculating a differential amount, or may be obtained by calculating a difference between adjacent minute partition region rows.
[0013]
And by welding part detection process determination which determines the site | part applicable to both the target site | part specified by such lightness detection process determination, and the target site | part specified by variation | change_quantity detection process determination, it is welded of a wheel rim. It becomes possible to detect a part appropriately and clearly. Accordingly, it is possible to appropriately perform a positioning operation such as rotating the wheel rim transferred to the valve hole drilling process or the air leakage inspection process so that the welded portion is in an appropriate position. Thus, dirt and scratches are not mistakenly detected as a welded part, so in the valve drilling process, it is possible to prevent the valve hole from being accidentally processed in the vicinity of the welded part. The occurrence rate can be significantly reduced, and productivity is further improved. Similarly, since the air leak inspection process is appropriately performed at the welded portion, it is possible to prevent the occurrence of complaints due to the air leak without overlooking defective products. In addition, since the detection of the welded portion is performed by image data analysis processing, the time required for inputting the wheel rim information required for the welded portion detection can be shortened as compared with the conventional inspection method described above. The welded part detection process proceeds quickly, and the production efficiency of the wheel rim can be further increased. Furthermore, since it is possible to detect relatively large dirt or scratches in the lightness detection process determination and the change amount detection process determination, there is also an excellent advantage that such defective products can be easily found. is there.
[0014]
A detection method (claim 2) is proposed in which the predetermined brightness change mode in the above-described change detection process determination is set by the absolute value of the brightness change amount and the change rate of the brightness change amount. Here, the change rate of the lightness change amount is a rate of increase or decrease of the lightness change amount between successive rows of minute compartments, and represents the gradient of the lightness change amount. Thus, as described above, the absolute value of the brightness change amount and the change rate of the brightness change amount rapidly decrease toward the minus side along the circumferential direction, and then increase toward the plus side. It is possible to set the brightness change mode of the welded portion that rapidly decreases. As a result, it is possible to accurately distinguish between the welded portion and dirt, scratches, and the like by the change amount detection processing determination, so that the welded portion can be appropriately and clearly detected by the welded portion detecting means of the present invention. .
[0015]
Further, the above-mentioned welded part detecting means is reflected from the opening direction of the wheel rim, and the inner peripheral surface of the part rising from the bead seat part to the rim flange and / or the well part coupled to the drop part from the bead sheet part. A detection method (claim 3) is proposed in which a weld is detected from image data of the peripheral surface. Here, the inner peripheral surface of the part rising on the rim flange and the inner peripheral surface of the well portion are projection surfaces projected from the opening direction of the wheel rim, and are relatively close to a plane perpendicular to the axial direction and wide in the radial direction. Has an area. Thereby, since the brightness of a micro division area can be detected in a comparatively bright range, it is possible to detect a welding part with low brightness clearly and easily. In addition, since the area in the radial direction of the micro-partition area row becomes wider, the area to detect and analyze the brightness increases, so it is easy to distinguish the dirt and scratches from the welded part, making the welded part more appropriate. Can be detected.
[0016]
Furthermore, a detection method (claim 4) is proposed in which the above-described image input means is provided with an image input device for inputting the wheel rim as a single image body from the opening direction. In this image input means, the image input device can detect the brightness distribution and the distribution of the brightness change amount of the entire wheel rim by inputting the image data once by taking the projection surface of the wheel rim as a single image. . Thereby, since the site | part which most represents the characteristic as a welding part can be specified by the welding part detection means, a welding part can be detected correctly and the misdetection which detects a different site | part can be prevented. Furthermore, since the analysis processing is performed with one image data, a process for combining a plurality of image data is not necessary, and thus the process of detecting the welded portion proceeds more rapidly. In addition to welds, it is possible to detect parts with low lightness and parts with high lightness change, so that dirt and scratches can be properly grasped and taken out from the production line according to the level and corrected. Etc. can also be performed. Furthermore, in such an image input device, since image data can be input with the wheel rim fixed, a control device that rotates the wheel rim during detection is required as in the conventional detection method described above. There is also an excellent advantage of not.
[0017]
On the other hand, a detection method (claim 5) is proposed in which the image input means includes an irradiation device that illuminates the wheel rim from the opening direction in the circumferential direction with the same brightness. By providing such an irradiation device, the wheel rim has a substantially constant brightness along the circumferential direction, so that different brightness caused by welds, dirt, scratches, etc. can be detected more clearly.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a two-piece type vehicle wheel rim 1 in which a wheel disc (not shown) is fitted on the inner peripheral surface thereof. The wheel rim 1 is formed of steel. In the wheel rim 1, rim flanges 5 a and 5 b for supporting the sidewall portions of the tire are formed at the opening edges on both sides, and bead seat portions 7 a and 7 b for seating the tire beads on the inner side in the wheel axial direction. Adjacent to each other. Here, flange neck surfaces 9a and 9b that are substantially perpendicular to the axial direction of the wheel rim 1 are formed on the inner peripheral side of the portion rising from the bead seat portions 7a and 7b to the rim flanges 5a and 5b. Further, a drop portion 3 for dropping the bead of the tire when the tire is mounted on the inner side in the wheel axial direction of the bead sheet portion 7a on the wheel design surface side through a well portion 6a rising from the drop portion 3 in the wheel radial direction. Is provided. A ledge portion 4 is coupled to the drop portion 3 in the wheel rear surface direction through a well portion 6b.
[0019]
Here, the wheel rim 1 is formed by a manufacturing process (not shown). In this manufacturing process, a steel plate-like base material having a predetermined substantially rectangular shape is joined to the short base by fillet welding or spot welding to form a cylindrical base, and then both opening edges thereof After performing flare processing to increase the degree of opening of the mold, a predetermined shape is formed by roll processing that clamps a predetermined mold from inside and outside, and further, expander processing that adjusts to a perfect circle shape is performed to form a desired wheel rim 1 Will be.
[0020]
The wheel rim 1 thus molded is transferred to the welded portion inspection step before being sent to the valve hole drilling step or the air leakage inspection step. FIG. 2 is a specific example of the welded part detection device 11 of the automobile wheel rim 1 according to the present invention. The welded part detection device 11 includes a fixing device 13 that fixes the wheel rim 1 that has been moved by the conveyor 14 at a photographing position, an irradiation device 15 that irradiates predetermined opening to the opening of the wheel rim 1, and a wheel rim. A detection camera 16 is provided that captures an image of a projection surface projected from one design surface side opening direction and inputs the image data. Further, the fixing device 13 and the detection camera 16 are connected to each other, and analysis processing is performed based on these controls and image data obtained from the detection camera 16 to detect the welded portion 2 (see FIG. 1) of the wheel rim 1. A detection processing device 12 is provided.
[0021]
Here, the wheel rim 1 is intermittently transferred to the fixing device 13 by the conveyor 14. Then, the fixing device 13 is configured so that the projection surface of the wheel rim 1 projected from the opening direction by the hydraulic lock 17 is within a range where the detection camera 16 can shoot at a time. The horizontal position and the vertical position with a predetermined vertical distance are locked at the set photographing position. Further, in the fixing device 13, when the welded portion 2 of the wheel rim 1 is detected, the wheel rim 1 is rotated so that the welded portion 2 is in a predetermined position with respect to the center of the wheel rim 1. It also has a turning function.
[0022]
The detection camera 16 is provided at a predetermined position at a predetermined vertical distance above the substantially central axis of the wheel rim 1 locked by the fixing device 13 and is fixed by the fixing device 13. The projection surface of the wheel rim 1 is set within a range that can be photographed at one time. Then, an image of the projection surface of the wheel rim 1 is taken and the image data is transmitted to the detection processing device 12. The detection camera 16 inputs an image with a constant vertical distance when the outer diameter of the wheel rim 1 is of the same type. When the wheel rim 1 has a different outer diameter, the detection camera 16 has an outer diameter of the wheel rim 1. In accordance with the diameter, the vertical position of the detection camera 16 is changed to control the vertical distance. Further, the detection camera 16 is controlled so as to be focused on the above-described flange neck surface 9a of the wheel rim 1. That is, in the present embodiment, the welded portion 2 is detected from the image data of the flange neck surface 9a (see FIG. 4).
[0023]
Moreover, in the irradiation apparatus 15 mentioned above, the opening of the wheel rim 1 is irradiated with light of a predetermined brightness so that the wheel rim 1 has a constant brightness in the circumferential direction. The irradiation devices 15 and 15 are arranged so as not to prevent the above-described detection camera 16 from photographing the projection surface of the wheel rim 1, and to prevent the irradiation light from interfering with the wheel rim 1. Is.
[0024]
Further, the above-described detection processing device 12 is configured by a so-called computer control device including a substrate circuit (not shown) for arranging a central processing unit (not shown) and a storage device (not shown). Yes. In the storage device of the detection processing device 12, the welded portion 2 of the wheel rim 1 is detected based on an operation program for controlling and operating the detection camera 16 and the fixing device 13 and image data of a projection plane photographed by the detection camera 16. And a detection processing program. The substrate circuit of the detection processing device 12 is connected to the fixing device 13 and the detection camera 16 via an input port for receiving image data and an output port for transmitting an operation command and the like. Further, in this storage device, according to the brightness irradiated by the irradiating device 15, the determination lightness value X of the determination reference value as the lightness of the welded portion and the determination lightness change form Y representing the lightness change of the welded portion 2 are stored. Has been. Here, in the determination lightness change mode Y, it is determined by a predetermined absolute amount of the lightness change amount and a predetermined change rate of the lightness change amount.
[0025]
Such a detection processing device 12 detects the welded portion 2 of the wheel rim 1 by analyzing the lightness of the flange neck surface 9a of the wheel rim 1 based on the image data of the projection surface. . Here, as the lightness analysis processing, the image data of the flange neck surface 9a is extracted from the image data of the wheel rim 1 input from the detection camera 16, and the image data is converted into the circumferential direction and the radial direction as shown in FIG. Are divided into a plurality of minute compartments 20, and the brightness of each minute compartment 20 is detected from the image data. Then, the brightness of the micro-partition area 20 is integrated for each micro-partition area row 21 along the radial direction, and the integrated brightness of the micro-partition area row 21 is calculated. Thereby, as shown in FIG. 6, the distribution of the integrated brightness in the circumferential direction is obtained. Further, by differentiating the integrated brightness by the micro-partition area row 21, the amount of change in brightness between successive micro-partition area rows is calculated. Thereby, as shown in FIG. 7, the distribution of the brightness change amount in the circumferential direction is obtained. Further, the change rate is calculated from the distribution of the brightness change amount. By determining the integrated brightness, the brightness change amount, and the change rate calculated in this way based on the above-described determination brightness X and determination brightness change mode Y, processing for detecting the welded portion 2 is performed.
[0026]
A detection control method for detecting the welded portion 2 of the wheel rim 1 by the above-described detection processing device 12 will be described with reference to the flowchart of FIG.
As described above, when the wheel rim 1 is transferred to the fixing device 13 by the transport conveyor 14, the detection processing device 12 controls and operates the hydraulic lock 17 of the fixing device 13 according to the operation program. 1 is fixed at a predetermined photographing position. Further, in accordance with the operation program, the detection camera 16 captures a projection plane in which the wheel rim 1 is viewed from the opening direction on the design plane side, and this image data is input to the detection processing device 12. Analysis processing by the detection processing program is executed by this image data. First, the center of the wheel rim 1 is calculated based on the image data, the image data of only the wheel rim 1 is extracted, and the flange neck surface 9a is extracted (see FIG. 4). Then, the image data of the flange neck surface 9a is virtually divided into the circumferential direction and the radial direction with the center of the wheel rim 1 as the base point, as described above, to create a plurality of minute partitioned regions 20 ( (See FIG. 5). Note that the number of the minute partition regions 20 is determined according to the minimum pixel of the detection camera 16, and can be set to the same size as the minimum pixel or a size that is a multiple of the same. Then, the lightness in each minute partition area 20 is detected from the image data, and the integrated brightness of the minute partition area row 21 is calculated. Comparing the integrated brightness of each micro-division area row 21 with the above-described determination brightness X, a set of micro-division area rows 21 adjacent to each other of the micro-division area row 21 having an integrated lightness lower than the determination lightness X is obtained. The target region 22 is assumed.
[0027]
On the other hand, the amount of change in brightness between successive minute section area rows is calculated from the integrated brightness of the minute section area row 21, and the rate of change is also calculated. The brightness change form obtained by the brightness change amount and the change rate thereof is compared with the determined brightness change form Y, and a part having the same form is set as the target part 23. And the site | part corresponding to both the target site | part 22 determined by said integrated brightness and the target site | part 23 determined by the brightness change form is determined as the welding part 2. FIG. In this way, the welded portion 2 of the wheel rim 1 is detected.
[0028]
Here, even if the flange neck surface 9a of the wheel rim 1 is soiled or scratched, there is a possibility that it becomes the target portion 22 depending on the integrated brightness, but the change form different from the brightness change form Y Therefore, it is not determined as the welded portion 2.
[0029]
When the welded portion 2 is detected in this way, the detection processing device 12 rotates the wheel rim 1 by the fixing device 13 so that the welded portion 2 is in a predetermined position with respect to the center of the wheel rim 1. Let Thereafter, the wheel rim 1 is released from the fixing device 13 and is transferred to the next valve drilling step (not shown) while maintaining the position, and the wheel rim 1 is separated from the welded portion 2 at a predetermined position. Thus, a valve hole is formed. Further, in the next air leakage inspection step, an air leakage inspection is performed at the welded portion 2 (not shown). On the other hand, the new wheel rim 1 is transferred to the fixing device 13 of the welded part detection device 11 by the transport conveyor 14, and the welded part 2 is detected in the same manner as described above.
[0030]
Thus, in the present embodiment example, it is possible to properly detect the welded portion 2 of the wheel rim 1 without erroneously detecting dirt or scratches. Therefore, the valve hole machining is performed at an appropriate position by the subsequent valve hole drilling process. Furthermore, even in the air leakage inspection process, the welding portion 2 is appropriately performed. Thus, it is possible to prevent the occurrence of defective products such as defective valve hole positions and poor air leak inspection caused by erroneously detecting the welded portion 2, thereby further improving the production efficiency of the desired wheel rim 1. obtain.
[0031]
In such an embodiment, a defect determination standard and a defect change mode may be set in the detection control unit so that relatively large dirt or scratches can be detected. Thereby, since the defective product can be easily detected from the integrated brightness of the minute partition region row 21 and the brightness change amount thereof, when the defective product is detected, it is once taken out from the production line, and further inspection and It is also possible to make corrections.
[0032]
In the above-described embodiment, the detection method uses the image data of the flange neck surface 9a in order to detect the welded portion 2. As another method, the image data of the inner peripheral surface of the well portion 6a is used. Or a method using image data of both the flange neck surface 9a and the well portion 6a. Further, the projection surface is photographed by the detection camera 16 from the back side of the wheel rim 1, and the welded portion 2 is detected by analyzing the brightness on the inner peripheral surface of the flange neck surface 9b and the well portion 6b. Also good.
[0033]
In the embodiment described above, the wheel rim 1 that has been transported on the conveyor 14 as shown in FIG. 1 is fixed by the fixing device 13, and the image data input by the detection processing device 12 by the detection camera 16 is used. In this method, the welded portion 2 is detected by analysis processing. As another method, the wheel rim 1 on the conveyor 14 is grasped by a robot hand or the like, and a single image is obtained by a fixed detection camera 16. It is also possible to carry to a predetermined photographing position where input is possible and photograph the projection surface of the wheel rim 1. In this method, according to the welded portion 2 detected from the image data of the projection surface, the robot hand transfers the wheel rim 1 to the next step so that the welded portion 2 is in a predetermined position. It is also possible to perform a control operation to be set on the conveyor 14, a control operation to be directly set on the valve punching device, or the like. In this way, in the method of transporting the wheel rim 1 to the imaging position of the fixed detection camera 16 by the robot hand, the imaging position can be changed at any time depending on the outer diameter of the wheel gripped by the robot hand. There is also an excellent advantage that the wheel rim 1 of various sizes can be easily accommodated.
[0034]
The present invention is not limited to this form, and can be implemented in various forms without departing from the gist of the present invention. In addition to the steel wheel rim, the present invention is made of aluminum or magnesium. It can implement suitably also to wheel rims, such as.
[0035]
【The invention's effect】
The present invention divides the image data of the projection surface of the wheel rim input by the image input means into a plurality of minute sections in the circumferential direction and the radial direction by lightness detection processing determination of the weld detection means, A set of minute compartment regions that are adjacent to each other in a minute compartment region in which the integrated brightness of the minute compartment region calculated from the lightness of each minute compartment is lower than the predetermined judgment lightness is defined as a target region. At the same time, the change amount detection processing determination calculates the amount of change between successive rows of minute compartments in the circumferential direction from the integrated lightness, and determines the target site where this lightness change amount becomes a predetermined lightness change form In addition, since it is a welded part detection method (claim 1) that detects a part corresponding to both the lightness detection process determination and the change amount detection process determination as a welded part, dirt, scratches, etc. are erroneously detected. Detected as weld Rukoto no, it is possible to properly and clearly detects the welding portion of the wheel rim. In addition, by properly detecting the welded part, it is possible to prevent defects in the valve hole machining position and not to overlook defects due to air leakage in the welded part, which can further improve the productivity of the wheel rim. it can. Further, since it is possible to detect relatively large dirt or scratches in the lightness detection process determination and the change amount detection process determination, there is also an excellent advantage that such defective products can be easily found. .
[0036]
Here, in the detection method (claim 2) in which the predetermined brightness change mode in the above-described change amount detection process determination is set by the absolute amount of the brightness change amount and the change rate of the brightness change amount, Since it is possible to accurately distinguish the welded portion from dirt and scratches by the amount detection processing determination, the welded portion can be detected more appropriately and clearly by the detection method of the present invention.
[0037]
Further, the above-mentioned welded part detecting means is reflected from the opening direction of the wheel rim, and the inner peripheral surface of the part rising from the bead seat part to the rim flange and / or the well part coupled to the drop part from the bead sheet part. In the detection method (Claim 3) in which the welded portion is detected from the image data of the peripheral surface, the brightness of the micro-compartment area can be detected in a relatively bright range, and the brightness is detected and analyzed. Since the radial direction width of the minute partition region row is widened, the welded portion can be detected more appropriately and easily.
[0038]
In the detection method (Claim 4) in which the image input means described above is provided with an image input device that inputs the wheel rim as a single image body from the opening direction, the entire wheel rim can be obtained by inputting image data once. Since the lightness and the lightness change amount can be detected, it is possible to easily identify the portion that best represents the feature as the welded portion, and to detect the welded portion more accurately.
[0039]
On the other hand, in the detection method (Claim 5), in which the image input means includes an irradiation device that illuminates the wheel rim with the same brightness in the circumferential direction from the opening direction, the projection surface of the wheel rim is: Since the lightness can be substantially constant along the circumferential direction, different lightness caused by welds, dirt, scratches, etc. can be detected more clearly.
[Brief description of the drawings]
1 is a longitudinal sectional view of a wheel rim 1 for an automobile.
FIG. 2 is a side view showing a specific example of a welded part detection device 11 for an automobile wheel rim 1 according to the present invention.
FIG. 3 is a flowchart showing a detection process in the weld detection method of the present invention.
FIG. 4 is a plan view showing a flange neck surface 9a input by an image input unit according to the present invention.
5 is an enlarged view of a portion A of the flange neck surface 9a in FIG. 4 showing the processing contents for dividing the image data of the flange neck surface 9a into the minute compartments 20 by the welded portion detection means according to the present invention.
FIG. 6 is an explanatory view showing a specific example of the lightness distribution of the flange neck surface 9a analyzed by the weld detection unit according to the present invention.
FIG. 7 is an explanatory diagram showing a specific example of the brightness change distribution of the flange neck surface 9a analyzed by the weld detection unit according to the present invention.
[Explanation of symbols]
1 Car wheel rim 1
2 Welded part
9a, 9b Flange neck
11 Welded part detection device
15 Irradiation device
16 Detection camera
20 Micro compartment
21 Micro compartment row
22 Target part (judgment by lightness detection processing judgment)
23 Target region (determination based on change amount detection processing determination)

Claims (5)

An image input means for inputting image data of a projection surface reflected from the opening direction of the wheel rim,
This image data is divided into a plurality of minute compartments in the circumferential direction and the radial direction, and the brightness of each minute compartment area along the radial direction is calculated by integrating each minute compartment. Lightness detection processing determination that determines a set of minute partition region rows adjacent to each other as a target part when the minute partition region row is lower than a predetermined determination brightness,
A change amount detection process for calculating a change amount between successive circumferential subdivision rows from the integrated lightness and determining the lightness change amount as a predetermined brightness change form when the lightness change amount is in a predetermined lightness change form. Judgment and
A welded part detecting means comprising: a target part determined by lightness detection process determination; and a welded part detection process determination that determines a part corresponding to both the target part determined by the change amount detection process determination as a welded part. A method for detecting a welded portion of an automotive wheel rim, comprising: 2. The welded portion of an automobile wheel rim according to claim 1, wherein the predetermined brightness change mode in the change detection processing determination is set by an absolute amount of the brightness change amount and a change rate of the brightness change amount. Detection method. An image of the inner peripheral surface of the part rising from the bead seat portion to the rim flange and / or the inner peripheral surface of the well portion connected to the drop portion from the bead seat portion, as seen from the opening direction of the wheel rim. 3. A method for detecting a welded portion of an automobile wheel rim according to claim 1, wherein the welded portion is detected based on the data. 4. The vehicle wheel rim welding according to claim 1, wherein the image input means includes an image input device for inputting the wheel rim as a single image body from the opening direction. Part detection method. 5. The vehicle wheel rim according to claim 1, wherein the image input means includes an irradiation device that illuminates the wheel rim with the same brightness in a circumferential direction from an opening direction thereof. Welding part detection method.

Images