JP6402026B2 - Joining tool inspection device - Google Patents

Description

  The present invention relates to a joining tool inspection apparatus that inspects a joining tool used in, for example, a friction stir welding apparatus installed in an automobile production line.

  Conventionally, joining by friction stir is known as one method for joining superposed metal plates to each other. This joining is performed by rotating a rod-shaped joining tool having a pin on the axis of the tip around the axis and moving the tip of the joining tool into the stacked metal plates so as to push the metal plates together. Are softened by frictional heat with each other and stirred for solid phase bonding.

  By the way, in the friction stir welding as described above, if the tip side of the welding tool is deteriorated due to wear or the like, the metal plate may not be sufficiently stirred and there is a risk of poor bonding. Need to manage.

  In the production line where the friction stir welding device is installed, the tip side of the welding tool is generally managed by regular visual confirmation by the operator, but this visual confirmation is cumbersome and is avoided. In order to do this, for example, it is conceivable to apply the inspection device disclosed in Patent Document 1 to manage the state of the tip side of the welding tool. This inspection device periodically shoots the electrode with a camera from the side of the welding gun with the electrode attached and held at the tip of the welding gun, and calculates the electrode tip diameter and electrode length using the captured images. In addition, the state of the electrode tip or the like is confirmed, and whether or not the electrode is in a normal state is compared and determined to manage the state of the electrode.

JP 2009-160656 A

  By the way, the welding tool for friction stir welding is a part of the joint portion to be joined by using the joining tool after a part of the softened metal during stirring or an unnecessary object such as dust adheres to the tip portion. Bonding quality becomes unstable. Therefore, it is necessary to check whether or not any unnecessary material is attached when the joining tool is viewed from the tip side.

  Further, if the length of the pin provided at the tip of the welding tool is shortened due to wear or breakage, the stirring at the time of bonding may be insufficient, resulting in poor bonding. Therefore, it is necessary to manage the length of the pin at the tip of the welding tool in order to prevent the occurrence of bonding failure.

  However, when the above-mentioned joining tool is photographed with an apparatus such as Patent Document 1 and an attempt is made to grasp both the state of attachment of unnecessary objects on the tip side and the state in the length direction of the pin, joining is performed while changing the posture of the joining tool. The tip side of the tool must be shot multiple times with the camera, or the tip side of the welding tool must be shot multiple times while changing the camera position. The rate will be lowered.

  In order to avoid this, it is conceivable to photograph the welding tool from two directions at the same time with two cameras, but the number of cameras increases unnecessarily and the cost increases.

  The present invention has been made in view of such points, and the object of the present invention is low cost, can reduce the burden on the operator, and does not lower the operating rate of the production line. It is another object of the present invention to provide a welding tool inspection apparatus capable of appropriately managing a welding tool for friction stirring.

  In order to achieve the above object, the present invention is characterized in that the front end side of the welding tool is photographed with a camera from the axial direction of the welding tool while irradiating light on the peripheral edge of the pin of the welding tool. And

  Specifically, the present invention is directed to a joining tool inspection apparatus for inspecting a rod-like joining tool for friction stir welding having a pin on the tip axial center, and has taken the following solution.

  That is, in the first invention, a tool fixing means for fixing the joining tool at a predetermined reference position, and a side fixed to the reference position, and the joining tool is fixed at the reference position. Photographing the light source that emits light from the direction intersecting the axis of the welding tool toward the peripheral edge of the tip of the pin and the tip side of the welding tool fixed at the reference position from the axial direction of the welding tool And determining whether or not there is reflected light from the light source at the peripheral edge of the tip of the pin based on a processing result of the camera, an arithmetic processing unit that arithmetically processes a captured image captured by the camera, and a processing result of the arithmetic processing unit And a control unit having a determination unit.

  According to a second invention, in the first invention, a plurality of the light sources are arranged at equal intervals around the axis of the welding tool in a state of being fixed at the reference position, and the arithmetic processing unit is configured to A pin tip diameter calculator that calculates the tip diameter of the pin from the position of the reflected light, and the determination unit determines whether the calculation result of the pin tip diameter calculator is within a predetermined setting range; It is characterized by determining.

  According to a third aspect, in the first or second aspect, the arithmetic processing unit has a luminance value calculation unit that calculates a luminance value on a tip side of the joining tool, and the determination unit includes the luminance value calculation. It is characterized by determining whether the calculation result of a part exists in the predetermined setting range.

  In the first invention, when the length of the pin is shortened due to wear or breakage, the light emitted from the light source is not reflected on the pin. Therefore, in the photographed image obtained by photographing the tip side of the welding tool from the axial direction of the welding tool. By checking whether or not the reflected light is generated on the pin, it can be determined whether or not the length of the pin is shortened. Therefore, it is possible to know the state of attachment of unnecessary materials such as dust and the state of the pins in the length direction of the pins from the image taken with one camera, and the number of cameras is increased and the cost is increased. There is no. In addition, since the welding tool is photographed from only one direction using a single camera, it is possible to avoid increasing the inspection time by photographing the welding tool from a plurality of directions, and to reduce the operation rate of the production line. The joining tool can be managed without any problems. Furthermore, since it is not necessary for the worker to perform visual confirmation periodically, the workload of the worker can be reduced.

  In the second invention, since the tip diameter of the pin can be accurately determined, whether or not the tip of the pin is extremely worn and affects the quality of the joined portion at the time of joining is determined. Therefore, it is possible to prevent a joint portion with poor bonding from flowing out to a subsequent process.

  In 3rd invention, the unnecessary value adhering to the joining tool front-end | tip side differs in a brightness value from the other part in the picked-up image by a camera. Therefore, by confirming the difference in brightness value, it is possible to know quantitatively whether or not there is any unnecessary material attached to the tip of the welding tool before joining work, and it is possible to ensure that the joint part with poor joining does not flow out to the subsequent process. You can

It is a schematic front view of the friction stir welding apparatus provided with the welding tool inspection apparatus which concerns on embodiment of this invention. It is sectional drawing in the AA of FIG. 1 is a control block diagram of a welding tool inspection apparatus according to an embodiment of the present invention. It is the figure which image | photographed the front end side of the joining tool with the CCD camera from the axial direction. (A) is the B section enlarged view of FIG. 4, (b) is a figure in the middle of calculating the image of (a) in the pin tip calculation part. It is a flowchart at the time of the joining tool test | inspection by the joining tool test | inspection apparatus which concerns on embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiment is merely exemplary in nature.

  FIG. 1 shows a friction stir welding apparatus 10 including a welding tool inspection apparatus 1 according to an embodiment of the present invention. The friction stir welding apparatus 10 is arranged in a production line F of an automobile, and assembles a workpiece W from two plate-like press parts 11 by friction stir spot welding.

  The friction stir welding apparatus 10 includes an industrial robot 2 (tool fixing means) controlled by a servo motor.

  A joining unit 3 is attached to the tip of the arm 2a of the industrial robot 2, and the joining unit 3 includes a substantially cylindrical unit body 31 having a drive unit 31a therein.

  A chuck 32 is provided on one end side in the axial direction of the unit main body 31 so as to be able to hold the elongated rod-shaped joining tool 4 in a posture that coincides with the axial center of the unit main body 31. Thus, it is possible to move the welding tool 4 along the axis of the welding tool 4 while rotating the tool 4 around the axis.

  As shown in FIG. 2, the joining tool 4 includes a bar-shaped tool body 4a extending in the vertical direction, and a pin 4b projects from the center of the tool body 4a tip (one longitudinal end). .

  The right side of FIG. 1 with respect to the industrial robot 2 is a joining region X1 for assembling both the pressed parts 11, and the left side of FIG. 1 is an inspection region X2 for inspecting the tip side of the joining tool 4. ing.

  A pair of clamp devices 13 that can hold the pressed part 11 in a posture extending in the horizontal direction are spaced apart in the horizontal direction in the joining region X1.

  A rectangular parallelepiped support block 14 is disposed between the clamp devices 13, and the pressed parts 11 held by the clamp devices 13 overlap the support block 14.

  On the other hand, a frame 5 extending vertically is installed in the inspection region X2, and a box-shaped inspection device body 6 is attached to the upper end of the frame 5.

  The inspection apparatus main body 6 and the industrial robot 2 constitute the joining tool inspection apparatus 1 of the present invention.

  As shown in FIG. 2, the inspection apparatus body 6 includes a metal housing case 61 having a substantially rectangular parallelepiped shape.

  A communication hole 61 a that communicates with the interior of the housing case 61 is formed in the approximate center of the upper surface of the housing case 61, and the diameter of the communication hole 61 a is larger than the outer diameter of the joining tool 4.

  A cover plate 62 is attached to the upper surface of the housing case 61, and a tool insertion hole 62 a into which the joining tool 4 can be inserted is formed at the approximate center of the cover plate 62.

  The tool insertion hole 62 a is gradually reduced in diameter as it goes downward, and corresponds to the communication hole 61 a in a state where the cover plate 62 is attached to the housing case 61.

  An annular first protrusion 62b projects downward from the periphery of the tool insertion hole 62a of the cover plate 62, and its tip surface is in contact with the periphery of the communication hole 61a.

  In the first protrusion 62b, four slits 62d extending in the radial direction are formed at equal intervals in the circumferential direction. FIG. 2 shows only two slits 62d.

  On the other hand, on the outer peripheral edge of the cover plate 62, a second protrusion 62c protrudes downward, and its tip surface is in contact with the outer peripheral portion of the upper surface of the housing case 61.

  The center portion of the tool insertion hole 62a is the reference position Ba in the present invention, and when the joining tool 4 is inserted into the tool insertion hole 62a from above and fixed to the reference position Ba, The tip of the pin 4b corresponds to each slit 62d.

  In the space 12 between the housing case 61 and the cover plate 62, four blue LED light sources 7 are provided at positions corresponding to the respective slits 62d.

  That is, the four LED light sources 7 are arranged around the axis of the welding tool 4 fixed to the reference position Ba, and each of the LED light sources 7 is fixed to the reference position Ba. The light emitted from the LED light source 7 is condensed when passing through the slit 62d, travels in a direction intersecting the axis of the welding tool 4, and is reflected on the peripheral edge of the pin 4b. It is like that.

  A block-shaped camera unit 8 is disposed at a position corresponding to the communication hole 61 a inside the housing case 61.

  The camera unit 8 includes a holder main body 81 that forms a skeleton of the camera unit 8, and an opening 81 a is formed on the upper surface of the holder main body 81.

  A CCD camera 82 is accommodated inside the holder body 81 in a posture in which the photographing direction is upward.

  Further, a white plate 83 is attached to the middle part of the holder main body 81, and a white LED light source 83a for illuminating the front end surface of the welding tool 4 fixed to the reference position Ba is attached to the white plate 83. Several are attached.

  Further, a milky white resin diffusion plate 84 is provided on the upper portion of the holder main body 81, and the diffusion plate 84 diffuses light emitted from the LED light source 83a.

  The CCD camera 82 takes an image of the welding tool 4 fixed at the reference position Ba through the opening 81a from the tip side (in the axial direction of the welding tool 4).

  As shown in FIG. 3, a control panel 9 (control means) for controlling the industrial robot 2 and the inspection apparatus body 6 is connected to the industrial robot 2 and the inspection apparatus body 6.

  The control panel 9 performs arithmetic processing on the captured image P1 (see FIG. 4) captured by the CCD camera 82, and on the peripheral edge of the pin 4b based on the processing result in the arithmetic processing unit 9a. And a determination unit 9b for determining whether or not there is reflected light L1 from the LED light source 7.

  The arithmetic processing unit 9a calculates a pin tip diameter calculating unit 9c that calculates the tip diameter Ra of the pin 4b from the position of each reflected light L1 of each LED light source 7, and calculates the luminance value on the tip side of the joining tool 4. And a luminance value calculation unit 9d.

  Specifically, as shown in FIGS. 5A and 5B, the pin tip diameter calculation unit 9c changes the color tone of the captured image P1, changes the reflected light L1 to yellow, and is an area other than the reflected light L1. A photographed image P2 in which is changed to black is made.

  The pin tip diameter calculator 9c extracts the position where the color tone of the photographed image P2 changes greatly as the position corresponding to the periphery of the tip surface of the pin 4b (FIG. 5 ( b) Four red lines E1).

  Further, the pin tip diameter calculator 9c calculates distances R1 and R2 between the red lines E1 180 degrees apart around the pin 4b, and averages the obtained distances R1 and R2 to average the tip diameter of the pin 4b. Ra is obtained.

  Specifically, the luminance value calculation unit 9d calculates the luminance value of each pixel in a region other than the portion corresponding to the pin 4b on the distal end surface of the welding tool 4 in the captured image P1.

  If the determination unit 9b determines that the reflected light L1 is present at the periphery of the tip of the pin 4b, whether the calculation result (pin tip diameter Ra) of the pin tip diameter calculation unit 9c is within a predetermined setting range T1. It is determined whether or not.

  When the determination unit 9b determines that the pin tip diameter Ra of the pin 4b is within the setting range T1, whether or not the calculation result of the luminance value calculation unit 9d is within the predetermined setting range T2. It comes to judge.

  Further, the determination unit 9b displays each determination result on the display monitor 9e (display unit).

  And when the said control panel 9 assembles the workpiece | work W, while outputting the joining start signal to the said industrial robot 2, it arrange | positions the joining unit 3 on the press component 11 set to the clamp apparatus 13, and also the joining tool 4 The two press parts 11 are softened by frictional heat and agitated to be solid-phase bonded by pushing the tip side into the two press parts 11 while rotating.

  The control panel 9 outputs an inspection start signal to the industrial robot 2 to fix the welding tool 4 at the reference position Ba and inspect the welding device 4 when the welding tool 4 is inspected. An inspection start signal is output to inspect the distal end side of the joining tool 4 fixed to the reference position Ba.

  When the control panel 9 determines that there is a problem on the tip side of the welding tool 4, the control panel 9 outputs a line stop signal to a line control panel (not shown) of the production line F, while the tip of the welding tool 4 When it is determined that there is no problem on the side, a line continuation signal is output to a line control panel (not shown) of the production line F.

  Next, specific inspection control in the welding tool inspection apparatus 1 will be described based on the flowchart shown in FIG.

  First, after the joining operation in the joining region X1 is completed, the industrial robot 2 changes the posture of the arm 2a and fixes the joining tool 4 to the reference position Ba. Thereafter, a tool fixing completion signal is output from the industrial robot 2 to the control panel 9.

  When receiving the tool fixing completion signal from the industrial robot 2, the control panel 9 proceeds to step S1 in the flowchart of FIG. In this step S1, a photographed image P1 is obtained by photographing the tip side of the welding tool 4 fixed at the reference position Ba with the CCD camera 82 from the axial direction.

  Next, in step S2, the determination unit 9b determines whether or not all four reflected lights L1 from the LED light source 7 are present in the captured image P1.

  When the determination in step S2 is NO, that is, when the determination unit 9b determines that all four reflected lights L1 are not present in the captured image P1, the process proceeds to step S9, and the control panel 9 performs line control of the production line F. After outputting a line stop signal to the panel (not shown), the process proceeds to step S10 and a warning is displayed on the display monitor 9e.

  On the other hand, when the determination in step S2 is YES, that is, when the determination unit 9b determines that there are all four reflected lights L1 in the captured image P1, the process proceeds to step S3.

  In this step S3, the pin tip diameter calculator 9c calculates the tip diameter Ra of the pin 4b from the four reflected lights L1 shown in the captured image P1. Specifically, as shown in FIGS. 5A and 5B, first, the photographed image P2 in which the color tone of the photographed image P1 is changed, the reflected light L1 is yellow, and the area other than the reflected light L1 is black. Get. Next, a portion where the color tone of the photographed image P2 greatly changes is extracted as a position corresponding to the peripheral edge of the tip surface of the pin 4b (a red line E1 portion in FIG. 5B). Then, the distances R1 and R2 between the red lines E1 that are 180 degrees apart around the pin 4b are calculated, and the obtained distances R1 and R2 are averaged to obtain the pin tip diameter Ra, and then the process proceeds to step S4.

  Thereafter, in step S4, the determination unit 9b determines whether or not the pin tip diameter Ra is within a predetermined setting range T1.

  When the determination in step S4 is NO, that is, when the determination unit 9b determines that the pin tip diameter Ra is out of the set range T1, the process proceeds to step S9, and the control panel 9 controls the line control panel ( After the line stop signal is output to (not shown), the process proceeds to step S10 to display a warning on the display monitor 9e.

  On the other hand, when the determination in step S4 is YES, that is, when the determination unit 9b determines that the pin tip diameter Ra is within the setting range T1, the process proceeds to step S5.

  In step S5, the luminance value calculation unit 9d calculates the luminance value of each pixel in a region other than the portion corresponding to the pin 4b on the distal end surface of the welding tool 4 in the captured image P1, and proceeds to step S6.

  In step S6, the determination unit 9b determines whether or not the luminance value of each pixel calculated by the luminance value calculation unit 9d is outside the predetermined setting range T2 (abnormal value).

  When the determination in step S6 is YES, that is, when the determination unit 9b determines that the luminance value of each pixel calculated by the luminance value calculation unit 9d is outside the predetermined setting range T2, the process proceeds to step S9. The control panel 9 outputs a line stop signal to a line control panel (not shown) of the production line F, and then proceeds to step S10 to display a warning on the display monitor 9e.

  On the other hand, when the determination in step S6 is NO, that is, when the determination unit 9b determines that the luminance value of each pixel calculated by the luminance value calculation unit 9d is within the predetermined setting range T2, the process proceeds to step S7. After the control panel 9 outputs a signal for continuing the production line F to the line control panel (not shown) of the production line F, the control panel 9 proceeds to step S8 and displays on the display monitor 9e that there is no problem with the workpiece W.

  As described above, according to the embodiment of the present invention, when the length of the pin 4b is shortened due to wear or breakage, the light emitted from the LED light source 7 is not reflected on the pin 4b. By checking whether or not the reflected light L1 is generated on the pin 4b in the photographed image P1 obtained by photographing the tip side of the tool 4, it is possible to determine whether or not the length of the pin 4b is shortened. Accordingly, it is possible to know the state of attachment of unnecessary materials such as dust and the state of the pins 4b in the length direction of the joining tool 4 from the photographed image P1 photographed by one CCD camera 82, and the CCD camera 82 is wasted. There is no such thing as increasing the cost. Further, since the bonding tool 4 is photographed only from one direction using one CCD camera 82, it is avoided that the inspection time is increased by photographing the welding tool 4 from a plurality of directions. It is possible to manage the welding tool 4 without lowering the operation rate. Furthermore, since it is not necessary for the worker to perform visual confirmation periodically, the workload of the worker can be reduced.

  Further, since the tip diameter Ra of the pin 4b can be accurately determined, it is possible to determine whether or not the tip of the pin 4b is extremely worn and affects the quality of the joined portion before joining. It is possible to know, and it is possible to prevent the poorly joined portion from flowing out to the subsequent process.

  Further, an unnecessary object adhering to the tip of the welding tool 4 has a brightness value different from that of other portions in the captured image P1 obtained by the CCD camera 82. Therefore, by confirming the difference in luminance value, it is possible to know quantitatively whether or not unnecessary objects are attached to the tip of the welding tool 4 before the bonding work, and the bonded portion with poor bonding is reliably discharged to the subsequent process. You can avoid it.

  In the embodiment of the present invention, the CCD camera 82 is used for photographing the front end side of the joining tool 4, but a CMOS camera may be used.

  In the embodiment of the present invention, four LED light sources 7 are arranged in the space 12, but a plurality of LED light sources may be attached. In addition, although a blue LED is used for the LED light source 7, an LED other than blue is used as long as it is a color in which the boundary of the tip peripheral edge of the welding tool 4 is clearly displayed in the photographed image taken by the CCD camera 82. May be used.

  The present invention is suitable for, for example, a joining tool inspection apparatus that inspects a joining tool used in a friction stir welding apparatus installed in an automobile production line.

1 Joining tool inspection device 2 Industrial robot (tool fixing means)
4 Joining tool 4b Pin 7 LED light source 9 Control panel (control means)
9a Arithmetic processing unit 9b Judgment unit 9c Pin tip diameter calculation unit 9d Luminance value calculation unit 82 CCD camera

Claims (3)

A welding tool inspection device for inspecting a rod-shaped welding tool for friction stir welding having a pin on the tip axis,
Tool fixing means for fixing the joining tool at a predetermined reference position;
A light source that is fixed to the side of the reference position and that emits light from a direction intersecting the axis of the welding tool toward the peripheral edge of the pin in a state where the welding tool is fixed at the reference position. ,
A camera that photographs the tip side of the welding tool fixed at the reference position from the axial direction of the welding tool;
An arithmetic processing unit that performs arithmetic processing on a photographed image captured by the camera, and a determination unit that determines whether or not there is reflected light from the light source at the periphery of the tip of the pin based on a processing result of the arithmetic processing unit. A joining tool inspection device comprising a control means. In the joining tool inspection apparatus according to claim 1,
A plurality of the light sources are arranged at equal intervals around the axis of the welding tool in a state of being fixed at the reference position,
The arithmetic processing unit has a pin tip diameter calculator that calculates the tip diameter of the pin from the position of the reflected light of each light source,
The said determination part determines whether the calculation result of the said pin tip diameter calculation part exists in the predetermined setting range, The joining tool test | inspection apparatus characterized by the above-mentioned. In the joining tool inspection apparatus according to claim 1 or 2,
The arithmetic processing unit has a luminance value calculation unit for calculating a luminance value on the tip side of the joining tool,
The said determination part determines whether the calculation result of the said luminance value calculation part exists in the predetermined setting range, The joining tool test | inspection apparatus characterized by the above-mentioned.