JPH1089923A - Method and device for inspecting welded part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inspect a welded part for its appearance, such as the leg length, welded width, presence/absence of pits, etc., without human intervention by taking the picture of the weld with a camera. SOLUTION: An illuminating member 6 which evenly emits light is positioned along a weld 3 and the weld 3 is concentrically irradiated with the light from the member 6. The picture of the weld 3 is taken with a camera 5 which is positioned so that the camera 5 can pickup the image of the vertical reflected light from the weld 3 and picture signals are processed by means of a picture processor. The allowable values of the leg length E, welded width D, and pit of the weld 3 are stored in advance in the picture processor and the leg length value E, welded with value D, and pit value detected by processing the picture signals are compared with control values and, when the detected values do not fall within the control ranges, defects are outputted and recorded with a printer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of inspecting the appearance of a welded portion by photographing the welded portion with a camera device and detecting a leg length value, a weld width value, and a weld pit value of the welded portion, and The present invention relates to an inspection apparatus that performs this inspection method.

[0002]

2. Description of the Related Art When inspecting a welded portion of a structure or the like, since the welded portion cannot be destroyed, a nondestructive inspection such as an X-ray inspection, a magnetic inspection or an ultrasonic inspection is performed. It is common. In such a test,
Inspection personnel are required to have special qualifications, the inspection equipment is large, and the time required for inspection is long. For this reason,
When inspecting a welded part of a mass-produced product, it is general to perform a sampling destruction inspection and an entire appearance inspection. This appearance inspection is usually carried out visually by inspection personnel.

On the other hand, a camera in which photoelectric conversion elements (CCD elements) for converting light into electric signals are arranged in a matrix, a processing section for processing an image signal photographed by the camera, and a predetermined information are stored in the memory. Using a shape recognition device including an image processing device having a storage unit for storing and a comparison unit for comparing a signal from the processing unit and information stored in the storage unit, shooting the article with the camera, and storing the article. It is determined whether or not the information matches the information stored in the unit.

[0004]

Generally, in the appearance inspection of a welded portion, it is determined whether or not the width dimension of a welded portion (weld bead) is within a predetermined appropriate value range. That is, if the welding is fillet welding of a T joint, whether the leg length is appropriate, if the welding is fillet welding of a lap joint, whether the leg length is appropriate, and whether the weld bead is covered. When the periphery of the welding member is melted, it is determined whether or not the welding width is appropriate. Furthermore, it is also performed to check whether or not pores (pits) exist on the surface of the weld bead.

[0005] When the visual inspection of the welded portion as described above is performed by the visual inspection of the inspection personnel, there is a risk that oversight or the like may occur if the fatigue of the inspection personnel accumulates, and the uncertainty of the inspection cannot be avoided. is there.

Further, when the appearance inspection of the welded portion is performed by the shape recognition device including the camera and the image processing device, it is difficult to distinguish the weld bead from the metal surface around the bead. Since a large area is illuminated and photographed, there is a problem that it is difficult to extract only the welded portion from the photographed image.

An object of the present invention is to provide a method capable of inspecting a welded portion by using a camera and an image processing apparatus, and an inspection apparatus for performing the method.

[0008]

According to the present invention, there is provided a method for inspecting a welded portion, comprising arranging a camera device so that a reflected light image perpendicular to a surface in a leg length direction to be detected can be taken. Then, the reflected light image is shot by the camera device by irradiating light along the welded portion, the image signal is processed by the image processing device to detect the leg length value, and the detected leg length value and the preset leg length This is characterized in that a defect in the welded portion is detected by comparing the value with the value.

In the above inspection method, light is uniformly irradiated on the welded portion along the welded portion so that a reflected light image from the portion is an image having a larger amount of light than a reflected light image from another portion. By arranging this reflected light image in a direction perpendicular to the surface in the leg length direction and photographing with a camera device and processing an image signal,
A leg length value can be detected by extracting a welded portion from another portion. For this reason, by comparing the detected leg length value with the leg length value in the preset management range, the appearance inspection can be performed and the defect of the welded portion can be detected.

In the above inspection method, a reflected light image of the welded portion is photographed by a camera device, and an image signal is processed by an image processing device to detect a width value of the welded portion. It is preferable to detect a defect in the welded portion by comparing with a preset welding width value. In this case, the width value of the welding portion can be detected and compared with a preset welding width value. That is, by comparing the leg length value of the welded portion and the width value of the welded portion with the set values, the appearance inspection can be performed and the defect of the welded portion can be detected.

In order to increase the amount of reflected light from the welded portion, it is preferable to irradiate light from a direction parallel to the leg length direction to be detected. In this case, the irradiated light can illuminate only the welded portion without illuminating the surfaces of the welding base material and the member to be welded. Therefore, it is easy to rescue the welded portion from the image signal captured by increasing the amount of reflected light from the welded portion.

In particular, in the case where the welded portion is formed with a margin, by irradiating light from a direction parallel to the leg length direction to be detected, a shadow is generated on the opposite side of the light irradiation direction of the welded portion, and the welding is performed. The entire part cannot be illuminated. Therefore, in order to uniformly irradiate the welded portion with light, it is necessary to illuminate the opposite side of the extra bank. For this reason, when an extra bank is formed in the welded portion, it is preferable to arrange a reflecting member on the opposite side of the extra bank to reflect light emitted from a direction parallel to the leg length direction. In this case, the whole can be uniformly illuminated even if a margin is formed in the welded portion.

In the above inspection method, the welded portion is divided and photographed by a plurality of camera devices, and image signals from these camera devices are processed by an image processing device to detect leg length values or width values of the welded portions. Preferably, the detected leg length value or welding width value is compared with a preset leg length value or welding width value. In this case, each of the image signals photographed for each photographable area by the camera device is subjected to image processing to detect the leg length value and the width value of the welded portion, and the detected leg length value and the width value of the welded portion are set in advance. By comparing the set values, it is possible to perform a visual inspection and detect a defect in the welded portion regardless of the size of the area of the welded portion.

In the above inspection method, an image signal from a camera device photographing the welded portion is processed by an image processing device to detect a pit value, and the detected pit value is compared with a preset welding pit value. It is preferable to detect a welding pit defect by performing the above. In this case, the presence or absence of a pit can be inspected in addition to the leg length and the welding width of the welded portion to detect a defect in the welded portion.

Further, the inspection apparatus according to the present invention comprises: a light irradiating means for irradiating light along a welding portion; a camera device for photographing a reflected light image in a direction perpendicular to a leg length irradiated by the light irradiating means; An image processing apparatus having setting means for setting a value and a welding width value and a comparing means, wherein the image processing apparatus processes the image signal from the camera device, detects the leg length value and the width value of the welding portion, and sets the The defect value is output when the leg length value and the width value of the welded portion detected by comparing the set values of the above with the comparison means deviate from the set values.

In the above inspection apparatus, light can be uniformly irradiated along the welded portion by the light irradiating means, and a reflected light image of the welded portion in a direction perpendicular to the welded portion can be photographed by the camera device. Then, the image signal photographed by the camera device is processed by the image processing device, and in this process, the leg length value and the width value of the welding portion are detected and compared with respective preset values, and the detected leg length value or welding portion is detected. When the width value is out of the range of the set value, by outputting a defect signal, the appearance inspection of the welded portion can be performed.

In the above inspection apparatus, the back light irradiating means for irradiating light from the back side of the member to be welded, and the transmitted light radiated from the back light irradiating means and transmitted through the member to be welded is detected to detect the transmitted light. A reference position detecting means for detecting a reference position, and calculating a distance from a welding base material to an end of the member to be welded at a welding portion based on a signal from the reference position detecting means to calculate a virtual boundary line. It is preferable to provide a virtual boundary line calculating means for recognizing.

In the inspection apparatus constructed as described above, the reference position can be detected by irradiating light from the back side of the member to be welded by the back light irradiating means to detect light transmitted through the member. Then, the distance from the detected reference position to the end of the member to be welded at the welded portion is calculated, and the virtual boundary line can be recognized.

Therefore, for example, by setting the free end of the member to be welded or a hole formed in the member as a reference position,
Even in the case where the boundary line melts into the welded portion, the boundary line can be calculated and recognized as a virtual boundary line, and the leg length value can be detected based on the virtual boundary line.

In the above inspection apparatus, the image processing apparatus is provided with pit value setting means for setting a welding pit value and pit value comparing means for comparing an image signal from a camera device with the set welding pit value. It is preferable to output a pit defect signal when the signal deviates from the set welding pit value.

In the inspection apparatus configured as described above, the pit value of the welded portion is detected from the image signal of the welded portion captured by the camera, and is compared with a preset weld pit value. In addition to inspection of leg length and welding width, pits generated on the surface can be inspected.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred example of the above-described method for inspecting a welded portion and an inspection apparatus for executing the method will be described with reference to the drawings. FIG. 1 is a perspective view showing a typical example of a product to be inspected at a welded portion, FIG. 2 is a diagram showing a cross section of a welded portion welded to a lap joint by fillet welding, and FIG. 3 implements an inspection method according to the present invention. FIG. 4 is a view for explaining the irradiation direction of light at the time, FIG. 4 is a schematic view for explaining the entire configuration of the inspection apparatus according to the present embodiment,
FIG. 5 is a perspective view showing the configuration of the camera device, FIG. 6 is a diagram illustrating the configuration of the light irradiation member, FIG. 7 is a block diagram of a control system, and FIG. 8 is a flowchart.

In the method for inspecting a welded portion according to the present invention, the amount of light reflected from the welded portion is made larger than the amount of light reflected from other portions by uniformly irradiating the welded portion with light along the welded portion. The reflected light is photographed by a camera arranged so as to be able to photograph a reflected light image perpendicular to the surface in the leg length direction, an image of the welded portion is accurately extracted, and a predetermined process is performed to perform an appearance inspection. is there. Therefore, the welded portion can be inspected whether it is a fillet weld or a butt weld.

In this embodiment, as shown in FIG. 1, the welded structure to be inspected is a beam 1 made of H-shaped steel constituting a steel frame of a building and a lap joint on a web 1a of the beam 1. And the beam connecting piece 2 which is fillet welded. Therefore, the beam 1 becomes a welding base material and the beam connecting piece 2
Is the member to be welded. At a predetermined position of the beam connecting piece 2, a hole 2a through which a bolt is inserted is formed.

The beam connecting piece 2 is superimposed on the web 1a of the beam 1, and a predetermined side is welded to the web 1a to form a welded portion 3. And beam connection piece 2 welded to web 1a
Is projected onto the web 1a by the beam 1 and the beam connecting piece 2.
(A contour line of the beam connecting piece 2 and a line of a portion corresponding to a welded portion), and the boundary line 4 is actually recognized,
Alternatively, it is calculated and recognized as the virtual boundary line 4, and the welded portion 3
In this case, the leg length E and the width D of the welded portion are detected (see FIG. 2).

When the thickness of the beam connecting piece 2 is sufficiently large, FIG.
As shown in (b), the value of the leg length E is smaller than the thickness of the beam connecting piece 2, and the boundary line 4 actually exists in the welded portion 3 even in the case of fillet welding of a lap joint. Therefore, the value of the leg length E can be easily detected with reference to the boundary line 4. In this case, the value of the leg length E is equal to the value of the width D of the welded portion.

However, when the thickness of the beam connecting piece 2 becomes relatively thin, the thickness of the piece 2 and the value of the leg length E become equal, and as shown in FIG. It melts in and cannot be confirmed in reality. For this reason, it is possible to set a reference portion in advance in the beam connecting piece 2, assume the boundary 4 based on this portion, and calculate the leg length E based on the assumed virtual boundary 4. . Hereinafter, even if it is a boundary line that can be recognized in reality, or a virtual boundary line that has melted into the welded portion 3, the same reference numeral 4 is attached and the same reference numeral is used.

With respect to the steel structure of the welded structure, the "Architectural Institute of Japan" presents "Guidelines for Steel Structure Accuracy Measurement", and the inspection of the welded portion 3 is performed according to the guidelines. In the above guidelines, when the preset leg length is S and the actual leg length is L (L = S + ΔS), the limit tolerance of ΔS is 0 ≦ ΔS ≦ 0.8 S, ΔS ≦ It is set to 8mm. For pits, it is set that up to three joints of 1 m or less and up to three joints of more than 1 m for the densest 1 m.

Therefore, the leg length S is set in advance based on the specifications such as the thickness of the beam connecting piece 2 and the strength required for the welded portion 3 and the leg length value (corresponding to the leg length E) which is in the management range based on the above guideline. ), A welding width value (corresponding to the welding portion width D) are set, and the respective management ranges, the actually detected leg length E detection value (leg length value E), and the welding portion width D detection value (welding width) By comparing the width values D), it is possible to determine the quality of the welded portion 3.

In the inspection method according to the present invention, as shown in FIG. 3, a large number of photoelectric conversion elements (CCD elements) for converting light into electric signals are arranged in a matrix in place of the eyes of inspection personnel. Using the camera 5, the camera 5 is arranged so that a reflected light image perpendicular to the surface in the leg length direction to be detected can be taken (in a direction perpendicular to the surface of the beam connecting piece 2). In particular, the distance between the elements constituting the camera 5 is set in advance to a value corresponding to the actual dimensions in the photographable area.

The image of the web 1a, the beam connecting piece 2 and the welding portion 3 of the beam 1 photographed by the camera 5 is converted into an electric signal, and a predetermined process is performed to perform leg processing corresponding to the leg length E at the welding portion 3. A value E and a welding width value D corresponding to the width D of the welding portion are detected, and these detected values D and E are compared with preset leg length values and welding width values to determine the quality of the welding portion 3. I am trying to do it.

Since the purpose of the inspection method according to the present invention is to judge the quality of the welded portion 3, it is necessary that the welded portion 3 can be clearly distinguished from the photographed image, and It is necessary to be able to distinguish or recognize. However, if the photographable area of the camera 5 is uniformly illuminated, the surface of the web 1a or the beam connecting piece 2 and the welding portion 3
Is difficult to distinguish clearly.

Therefore, by irradiating the light uniformly along the welded portion 3 and illuminating the welded portion 3 brighter than the other portions, it can be clearly distinguished from the other portions. Therefore, an irradiation member 6 that irradiates light along the welded portion 3 is arranged. The irradiation member 6 only needs to be capable of uniformly irradiating the welded portion 3. However, in order to minimize reflected light from portions other than the welded portion 3 and to more easily distinguish the welded portion 3, it is preferable to irradiate a band-like light capable of uniformly illuminating the surface of the welded portion 3. . In particular, by irradiating light from a direction parallel to the surfaces of the web 1a and the beam connecting piece 2, the welded portion 3 is concentratedly illuminated, and the web 1
Preferably, it can be clearly distinguished from the illumination of the surface of the a and the beam connecting piece 2.

In the case where the beam connecting piece 2 is thin, the boundary 4 is often melted into the welded portion 3 and there is no guarantee that the beam 4 can be directly determined. Therefore, based on the hole 2a formed in the beam connecting piece 2, the distance from the end of the hole 2a set in advance in the design stage to the boundary 4 is calculated, and the boundary 4 is recognized as a virtual line. I have. A backlight member 7 is arranged on the back surface of the beam connecting piece 2 so that the camera 5 can reliably photograph the hole 2 a of the beam connecting piece 2. That is, the backlight member 7 is arranged on the side of the web 1a on which the beam connecting pieces 2 are stacked, and is configured so that light can be transmitted through the holes 2a by illuminating the beam connecting pieces 2 from behind.

In order to carry out the inspection method according to the present invention, the illuminating member 6 illuminates the welded portion 3 in a band shape and uniformly, and at the same time illuminates the light from the back side of the beam connecting piece 2 with the backlight member 7 to emit light. The light is transmitted through the hole 2a, and the camera 5 is arranged perpendicularly to the beam connecting piece 2 and photographed. In the image taken at this time, the welding portion 3 and the hole 2a of the beam connecting piece 2 are clearly distinguished from other portions. Therefore, the welding portion 3 and the hole 2a can be extracted by appropriately selecting the threshold value and binarizing the image signal.

As described above, the welding portion 3 and the hole 2a are extracted, the welding width value D of the welding portion 3 is detected, and the hole 2a is extracted.
The boundary line 4 is calculated based on a distance B set in advance with reference to the end of the hole 2a, the dimension A that is the most distant from the end of the hole 2a to the welded portion 3, and the end of the hole 2a is further calculated. The closest dimension C from the part to the weld 3 is calculated.
By detecting or calculating the dimensions A to D, the leg length value E can be calculated based on the assumed virtual boundary line 4.

Then, the detected welding width value D and the calculated leg length value E are compared with values of a preset control range, respectively, and a defect occurs when the welding width value D and the leg length value E deviate from the control range. , It is possible to inspect the welded portion 3.

In the above-described method for inspecting a welded portion, it is essential to uniformly irradiate light along the welded portion 3 and take an image with the camera 5, and the number of cameras 5 is not limited. That is, when the length of the welded portion 3 is long, a plurality of cameras 5 are arranged so as to face the photographable region including the welded portion 3, and image signals divided and photographed by the respective cameras 5 are processed. It is also possible to perform an inspection of the welded part.
In this case, each of the dimensions A to D is detected or calculated independently from the image signal photographed by each camera 5, and the detected welding width value D and the calculated leg length value E are compared with the values of the control range. Inspection of the welded part 3 can be performed.

As shown in FIG. 2 (b), when the boundary 4 has melted into the welded portion 3 and there is a large amount of excess, the opposite side of the irradiation member 6 is not sufficiently illuminated, and an accurate welding width value D is obtained. May not be detectable. Therefore,
It is necessary to uniformly illuminate the welding part 3 as a whole.
In this case, the irradiation members 6 may be provided on both sides with the welded portion 3 interposed therebetween, but there is a problem that the members 6 occupy a large area in the photographable area and an accurate inspection cannot be performed. For this reason, it is preferable to dispose an extremely thin reflecting mirror in opposition to the irradiation member 6 so that the light irradiated from the member 6 can be reflected to illuminate the entire welded portion 3.

As described above, by uniformly irradiating light along the welded portion 3, it is possible to detect a pit having a very small diameter formed on the surface of the welded portion 3. That is, when a pit is formed in the welded portion 3, the irradiated light is irregularly reflected according to the surface of the pit,
The amount of light captured by the camera 5 decreases and the welded portion 3
To be distinguished from other parts of Therefore, it is possible to detect the pit value by processing the image signal from the camera 5, and to detect the presence or absence and the number of pits from the detected pit value, and to compare the number with the preset number of management ranges. It is possible to inspect the pits in the welded portion 3 by using.

Next, an inspection apparatus for performing the above inspection method will be described. This inspection device performs a visual inspection including a leg length E and a width D of a welding portion 3 of a beam connecting piece 2 welded to a beam 1, and further includes a pit. Only one beam connection piece 2 is welded to the beam 1,
Further, the web 1a is not welded only in one direction. That is, the beam connecting pieces 2 may be welded to both ends in the longitudinal direction of the beam 1 and to both sides in the thickness direction of the web 1a. For this reason, the inspection apparatus according to the present embodiment is provided with four cameras 5 so that the beam connection piece 2 can be inspected even if it is the end of the beam 1 and is welded in any direction. ing.

As shown in FIG. 4, the inspection device identifies two systems of conveyors 11 and 12 for transporting the beam 1, four sets of camera devices 13 provided at predetermined positions of the conveyors 11 and 12, and identifies the beam 1. A bar code labeler 14 and a bar code reader 15 for attaching information for brushing, four sets of brush devices 16 provided at predetermined positions on the conveyors 11 and 12, and
, And a pusher 17 for moving the pusher.

Each of the conveyors 11 and 12 is configured as a roller conveyor in which a number of rollers each driven by a drive motor (not shown) are arranged. The beam 1 is transported along the arrow and stopped at a predetermined position. That is, the welded portion 3 at the end of the beam 1
When the camera reaches the camera device 13, the roller is stopped and the beam 1 is stopped. Note that a contact sensor such as a micro switch, a non-contact sensor such as a proximity switch or a photoelectric switch, an encoder, or the like can be used to detect that the welded portion 3 has reached the camera device 13.

The camera device 13 has a camera 5 for photographing the welded portion 3, and when the beam 1 reaches, the camera 5 is moved to the welded portion 3.
, And has a function of retracting the camera 5 from the welding portion 3 after the photographing is completed. In the present embodiment, the camera device 13
As shown in FIG.
It is configured to include a camera 5 of a base and an irradiation member 6 serving as a linear light irradiation unit for irradiating light linearly along the welded portion 3.

In the above configuration, each of the cameras 5 captures an image of a predetermined area, and determines the welded portion 3 within the capturing area. Then, a signal corresponding to the determination result in the photographing area is output, and the output signal is comprehensively determined to determine whether the beam 1 is good or not.

The camera 5 is fixed to the base 13a at a predetermined interval, and the base 13a is attached to the elevating member 13b so as to be able to move up and down. In addition, beam 1, beam connecting piece 2
The irradiation member 6 is detachably attached to the tip of the attachment member 13c, and the elevating member 13 is located at a predetermined distance from the irradiation member 6.
b is attached. Therefore, the distance between the irradiation member 6 and the camera 5 is kept constant.

The mounting member 13c is driven by a linear driving member 13d composed of an air cylinder, a linear guide or the like in a direction for moving the irradiation member 6 and the camera 5 toward and away from the welding portion 3. The linear drive member 13d is connected to the conveyors 11 and 12.
Is mounted on a stand (not shown) provided on the frame so that the position in the vertical direction can be adjusted.

In the camera device 13 configured as described above,
By operating the elevating member 13b, the camera 5 can be set at a desired height, and the welded portion 3 can be reliably taken into view regardless of the size of the beam 1 in the height direction. It is. Also, while the beam 1 is being conveyed, the irradiation member 6 and the camera 5 are retracted from the conveyance area of the conveyors 11 and 12, and when the beam 1 arrives and stops, the irradiation member 6 and the camera 5 are brought close to the welding portion 3 and photographed. It is possible to

As shown in FIGS. 6 (a) and 6 (b), the irradiating member 6 is adapted to irradiate light linearly along the welding portion 3 between the web 1a and the beam connecting piece 2. And a plurality of lamps 6b attached to the frame 6a, and a mirror 6c provided to face the lamp 6b.

The frame 6a has a substantially U-shaped cross section, a plate 6d having a lamp 6b attached thereto is fixed to an opening thereof, and a current-carrying wire or socket is provided in a space defined by the plate 6d and the frame 6a. Is provided.

The light emitted from the irradiation member 6 to the welding portion 3 is preferably a high-intensity lamp having high directivity. Such lamps include halogen lamps, xenon lamps, metal halide lamps, and the like. These lamps are mounted on a frame 6a to form an irradiation member 6, or these lamps are combined with an optical fiber and the light emitting side of the optical fiber is used. The irradiation member 6 can be configured by attaching to the frame 6a.

In this embodiment, an inexpensive L is used as the lamp 6b.
By using an ED and arranging a large number of LEDs in a line in three rows, light can be emitted linearly along the welded portion 3. In particular, the lamp 6b is arranged upright on the frame 6a so that light can be irradiated to the welded portion 3 from a direction parallel to the web 1a.

As the irradiation member 6, the mirror 6c is not always necessary. That is, when the welded portion 3 is a substantially clear fillet weld as shown in FIG. 2A, the mirror 6c is unnecessary. However, this is essential when a shadow is formed on the opposite side of the extra bank as shown in FIG. The mirror 6c only needs to have a function of reflecting light from the lamp 6b, and a mirror-polished plate of a relatively thin stainless steel plate or another material can be used. In this embodiment, a mirror 6c made of a stainless steel plate is used.

Next, the structure of a control system for controlling the inspection of the welded portion 3 of the beam 1 and the beam connecting piece 2 by the inspection device will be described with reference to FIG.
This will be described below.

In the figure, reference numeral 21 denotes a control device for controlling the entire inspection apparatus, a storage section 21a in which a program for proceeding the inspection process in the inspection apparatus is written, data input from the input device 22, and a camera. Primary storage unit for temporarily storing data output from the image processing device 23 connected to each of the five units
21b and an operation unit 21c.

Reference numeral 24 denotes an output device such as a printer for recording inspection result data for each beam 1 for which inspection has been completed. 25 is an interface.

The image processing device 23 includes a binarizing section for binarizing an image signal photographed by the camera 5, image data, and a welding portion 3.
It has a built-in image processing control unit such as a storage unit that stores data such as the value of the management range and a comparison unit that compares the image data with the value of the management range, and has an input unit such as a keyboard and a display unit such as a cathode ray tube. It is configured. For this reason, the image signals photographed by the individual cameras 5 are processed by the respective image processing devices 23, and pass / fail in the photographing area of the cameras 5 is determined.
The determination result is transmitted to the control device 21 via the interface 25.

Next, the procedure for inspecting the welded portion 3 between the beam 1 and the beam connecting piece 2 will be described, and the procedure for image processing will be described with reference to the flowchart of FIG.

First, a leg length value, a welding width value, and a pit value which are the control range of the welded portion 3 are input to the image processing device 23, and a threshold value for setting a binarization level is selected and input in advance. . Then, as shown in FIG. 4, when the beam 1 to be inspected is supplied to the conveyor 11 from the welding process which is a previous process, the bar code labeler 14 is attached to the flange or the web 1b of the beam 1.
A bar code label on which a unique number is described is attached. Next, the conveyors 11 and 12 are driven, and the beam 1 is conveyed so that the welded portion 3 faces the camera device 13.

When the web 1a of the beam 1 and the welded portion 3 of the beam connecting piece 2 face the camera 5, the linear drive member 13d of the camera device 13 operates to advance the mounting member 13c, and the frame 6a of the irradiation member 6 Is approached until it substantially contacts the web 1a, and at the same time, the camera 5 is set at a position separated from the welding portion 3 by a predetermined distance. A backlight member 7 attached to a frame (not shown) from between the conveyors 11 and 12.
To rise. Thus, the preparation for the inspection is completed.

After the inspection preparation is completed as described above, light is irradiated from the irradiation member 6 and the backlight member 7 to reflect the light from the welding portion 3 and the hole 2a formed in the beam connecting piece 2.
The light transmitted through the camera is photographed by the camera 5, and the photographed image signal is input to the image processing device 23.

In the image processing device 23, the input image signal at a specific moment is held and stored (S1). Next, the center of gravity of the hole 2a serving as a reference for detecting the welded portion 3 is detected (S2), and the inclination, displacement, and the like of the beam connecting piece 2 are detected. Further, a position (dimension B in FIG. 2) where the boundary line 4 should be based on the hole 2a is calculated, and a virtual reference line 4 is assumed (S3).

Next, an average value in a predetermined area near the virtual line is measured (S4). This processing is performed in order to prevent the irradiated light from being irregularly reflected and having low brightness when there is unevenness in the vicinity of the welded portion 3 and to prevent the light from being determined as a non-welded portion. Next, the welding portion 3 is binarized (S5). Furthermore, noise existing in the image is removed, and only the welded portion 3 is extracted, and data of the extracted welded portion 3 is stored (S6, S7).

The leg length value E, the welding width value D and the dimensions A and C in FIG. 2 are calculated from the stored data of the welding portion 3, and the obtained result is compared with a previously stored management range. When the result is within the management range, the process proceeds to the pit inspection step, and when the result is out of the management range, a defect is output to the control device 21 and the process proceeds to the pit inspection step (S
9, S10). Thus, the inspection for the leg length E and the welding width D of the welding portion 3 is completed.

Next, the input image stored in step 1 is read, and a process of sequentially applying a 3 × 3 maximum filter three times and a process of applying a minimum filter three times are performed.
Subtract input image from minimum value filter image (S11-
S14). By binarizing the signal (S15), data corresponding to the pit can be obtained. After obtaining the data corresponding to the pits, the image data of the welding portion 3 is read out again and the pit data is superimposed on the data, whereby the actual pit data existing in the welding portion 3 (from the data corresponding to the pits) (Pit value), and compares the pit value with a previously stored management range. If the comparison result is within the management range, the process proceeds to the next operation. On the other hand, a defect is output and the process proceeds to the next operation (S16 to S19).

By performing the above series of procedures, the image processing apparatus 23 based on the image signals captured by each camera 5
The determination operation of the welding portion 3 by the above is completed. The control device that has received the output of either pass or fail from each image processing device 23 makes a comprehensive judgment on the specific beam 1, outputs the judgment result together with a unique number by a bar code, and records it on the printer 24.

The beam 1 for which the appearance inspection of the welded portion 3 has been completed as described above is conveyed downstream by the conveyors 11 and 12, and the spatter attached to the periphery of the welded portion 3 is removed by the brush device 16. It is conveyed to the next process together with the recorded inspection result.

In this embodiment, the welded portion 3 is formed of the web 1a.
Although the case where the beam connecting piece 2 is formed as a lap joint and the boundary 4 is melted into the welded portion 3 during welding has been described, the inspection method of the present invention is not limited to the above-described structure. No, fillet welding and boundary line 4
It can be inspected in exactly the same manner even for a welded portion where can be clearly distinguished and a welded portion made of butt welding.

That is, in the case of fillet welding in which the boundary line 4 can be clearly discriminated, the leg length E and the width D of the welded portion become the same, and the inspection can be performed with less data to be calculated and compared. is there. Even in the case of butt welding,
Since the leg length E is the same as the width D of the welded portion, the inspection can be performed in the same procedure by replacing the leg length E with the width D of the welded portion.

[0070]

As described above in detail, in the method for inspecting a welded portion according to the present invention, the welded portion is photographed by a camera, the image signal is processed to detect the leg length value, and the leg length value is set in advance. By comparing with the value of the controlled range, the appearance inspection can be performed without using the inspection staff.

In particular, by irradiating light uniformly along the welded portion to increase the brightness of the portion, the welded portion can be clearly distinguished from other portions. Therefore, it is possible to accurately extract the welded portion, and the leg length and the width of the welded portion can be clearly determined. Therefore, the leg length value,
By calculating the welding width value and the pit value and comparing the calculated value with the preset management range, an accurate appearance inspection can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a typical example of a product whose weld is to be inspected.

FIG. 2 is a view showing a cross section of a welded portion obtained by fillet welding to a lap joint.

FIG. 3 is a diagram illustrating a light irradiation direction when the inspection method according to the present invention is performed.

FIG. 4 is a schematic diagram illustrating an overall configuration of the inspection apparatus according to the embodiment.

FIG. 5 is a perspective view showing a device configuration of the camera.

FIG. 6 is a diagram illustrating a configuration of a light irradiation member.

FIG. 7 is a block diagram of a control system.

FIG. 8 is a flowchart.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Beam 1a Web 2 Beam connection piece 2a hole 3 Welded part 4 Boundary line (virtual boundary line) 5 Camera 6 Irradiation member 6c Mirror 7 Backlight member 11, 12 Conveyor 13 Camera device 14 Barcode labeler 15 Barcode reader 16 Brush device 17 Pusher 21 Control unit 22 Input unit 23 Image processing unit 24 Output unit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takehisa Watanabe 6-4100 Asahicho, Nobeoka-shi, Miyazaki Asahi Engineering Co., Ltd. (72) Inventor Hidenori Matsumiya 513-15-202, Furusawacho, Hikone-shi, Shiga Prefecture 72) Inventor Masayuki Fuse 283 Shindo, Gokaso-cho, Kanzaki-gun, Shiga Prefecture (72) Inventor Hiroshi Isobe 3-31 Hibarigaokacho, Yokaichi-shi, Shiga Prefecture

Claims (7)

[Claims] 1. A camera device is arranged so that a reflected light image perpendicular to a surface in a leg length direction to be detected can be photographed, and light is irradiated along a welded portion, and the reflected light image is photographed by the camera device. The image signal is processed by an image processing device to detect a leg length value, and a defect of the weld portion is detected by comparing the detected leg length value with a preset leg length value. Inspection methods. 2. A reflected light image of a welded portion is photographed by a camera device, an image signal is processed by an image processing device to detect a width value of the welded portion, and the detected width value of the welded portion is set to a predetermined welding value. The method for inspecting a welded portion according to claim 1, wherein a defect of the welded portion is detected by comparing with a width value. 3. A divided portion of a welded portion is photographed by a plurality of camera devices, and image signals from these camera devices are processed by an image processing device to detect a leg length value or a width value of the welded portion. 3. The method according to claim 1, wherein the welding width value is compared with a preset leg length value or welding width value. 4. A pit value is detected by processing an image signal from a camera device photographing a welding portion by an image processing device, and comparing the detected pit value with a preset welding pit value. The method for inspecting a welded portion according to any one of claims 1 to 3, wherein the detection is performed. 5. A light irradiating means for irradiating light along a welding portion, a camera device for taking a reflected light image in a direction perpendicular to a leg length irradiated by the light irradiating means, and setting a leg length value and a welding width value. An image processing device having setting means and a comparison means for performing processing, wherein the image processing apparatus compares the leg length value and the welding width value detected by processing the image signal from the camera device with the setting value of the setting means by the comparison means. A defect signal is output when the detected leg length value and welding width value deviate from set values. 6. A back light irradiating means for irradiating light from the back side of the member to be welded, and detecting a transmitted light transmitted from the member to be welded irradiated from the back light irradiating means to detect a reference position of the member to be welded. A reference position detecting means, and a virtual boundary for recognizing a virtual boundary line by calculating a distance from a welding base material to an end of the member to be welded at a welding portion based on a signal from the reference position detecting means. The welding inspection apparatus according to claim 5, further comprising a line calculating unit. 7. An image processing apparatus is provided with pit value setting means for setting a welding pit value and pit value comparing means for comparing an image signal from a camera device with the set welding pit value. 7. The welding inspection system according to claim 5, wherein a pit defect signal is output when the detected pit value deviates from the set welding pit value.