JPH0875895A - Fuel rod circumference welding apparatus - Google Patents

Abstract

PURPOSE: To judge the quality of a circumference welded part quickly and precisely by installing a reference position data diciding means and a judging means which judges based on bead shape image data after circumference welding. CONSTITUTION: A fuel rod coating pipe 2 plugged with a terminal plug 3 is inserted into a chamber 5 and brought into contact with a contact jig 13 by a driving mean 8, lamps 12, 32 are lighted up, the peripheral part of a boundary line 6 of the pipe 2 and the plug 3 is photographed by a picture taking means 10, and the position of the pipe 2 is identified by a coating pipe moving degree detecting means 20. Moreover, based on image data the tip shape of an arc welded electrode 7 is confirmed, the quality is judged, and the electrode 7 is so shifted by a control signal of a movement controlling apparatus as to put the electrode at the position corresponding to the line 6. The boundary part of the pipe 2 and the plug 3 is circumference-welded in the circumferential direction by the electrode 7 and one turn of the circumference of the welded part is photographed by the means 10. The resulting image is corrected based on the movement degree in the axial direction detected by the means 20 and the quality of the circumference welded part is judged based ont the corrected image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel rod circumferential welding device for circumferentially welding a cladding tube and an end plug of a fuel rod used in a nuclear reactor.
In particular, the present invention relates to a fuel rod circumferential welding device capable of inspecting a circumferential welded portion and automatically making a pass / fail judgment. Further, the present invention relates to a fuel rod welding apparatus capable of feeding back the inspection data obtained by the inspection of the circumferential welded portion to welding conditions to obtain an optimum circumferential welded portion.

[0002]

2. Description of the Related Art A fuel rod used in a nuclear reactor is provided in a fuel rod cladding tube of a zirconium alloy (for example, Zircaloy 2).
It is manufactured by inserting a large number of columnar uranium dioxide pellets, inserting end plugs into the openings of the fuel rod cladding tubes, and circumferentially welding these end plugs and the fuel rod cladding tubes.

Since the fuel rod cladding tube and the end plug of the fuel rod must be circumferentially welded with high airtightness, an operator visually checks the circumferential welded portion by using a gauge to determine the welding position, bead width, etc. The welded state was inspected to determine whether the peripheral welded portion was acceptable or not. Further, the welding conditions in the next fuel rod circumference welding work are determined by observing the inspection result of the welding state.

[0004]

However, in the prior art, the inspection of the circumferential welding state of the fuel rods is performed visually by the operator, so that the inspection work requires skill and a great deal of inspection work is required. There is a problem that man-hours are required. Further, since the welding position inspection is based on the length from the end face of the end plug, there is also a problem that strict accuracy control of the end plug size is required. Further, unless the welding state inspection result is obtained, the welding conditions for the next fuel rod circumference welding work cannot be determined, and further, the welding conditions cannot be changed in accordance with the change over time, and There is also a problem that the welding quality changes.

The present invention has been made in view of the above circumstances. It is possible to quickly and accurately determine whether a peripheral welded portion is acceptable or not. Further, the inspection data obtained by the inspection of the peripheral welded portion is used as welding conditions. It is an object of the present invention to provide a fuel rod circumferential welding device which can always obtain an optimum circumferential welding portion by feeding back the fuel rod circumferentially.

[0006]

According to a first aspect of the present invention, there is provided a fuel rod circumferential welding apparatus in which a fuel rod cladding tube equipped with an end plug is moved in an axial direction, and one end of the fuel rod cladding tube. Part for inserting a welding chamber, an arc welding electrode arranged so as to face the boundary line between the end plug of the fuel rod cladding tube inserted into the welding chamber, and the fuel rod cladding tube inserted into the chamber And a driving means for rotating around the axis, the fuel rod circumferential welding device comprising: a borderline image pickup means for picking up an image of the vicinity of the borderline; and an image taken before the start of the circumferential welding by the borderline image pickup means. Reference position data determining means for determining the position of the boundary line from the image data, and the bead shape image data and the reference position data obtained by imaging the peripheral welded portion by the boundary vicinity image capturing means after the peripheral welding is completed. On the basis of Characterized in that the determining means for performing the acceptance judgment of the serial peripheral weld is provided.

A fuel rod circumference welding apparatus according to a second aspect of the present invention is the fuel rod circumference welding apparatus according to the first aspect, wherein the fuel rod cladding tube measures a rotation amount and an axial displacement amount of the fuel rod cladding tube. A movement amount detecting means is provided to detect the axial displacement amount of the fuel rod cladding tube during the circumferential welding and during imaging of the circumferential welding portion by using the rotation amount of the fuel rod cladding tube as a parameter, thereby correcting the reference position data. It is characterized by

A fuel rod circumference welding apparatus according to claim 3 of the present invention is the fuel rod circumference welding apparatus according to claim 1 or 2.
The reference position data determining means may include a line marker that obliquely projects a line mark on the fuel rod cladding tube.

A fuel rod circumference welding apparatus according to a fourth aspect of the present invention is the fuel rod circumference welding apparatus according to any one of the first to third aspects, in which the position adjusting means of the arc welding electrode and the arc welding electrode are arranged. Welding electrode tip vicinity imaging means for imaging the vicinity of the tip portion, arc welding electrode position data determination means for determining the position of the arc welding electrode imaged by the welding electrode tip vicinity imaging means, and the bead shape image data And a welding condition control means for adjusting the welding conditions by determining the optimum values of the welding parameters such as the arc welding electrode position, the welding current and the welding speed based on the reference position data and the arc welding electrode position data. And

A fuel rod circumference welding apparatus according to a fifth aspect of the present invention is the fuel rod circumference welding apparatus according to the fourth aspect, wherein the arc welding electrode position data determining means is oblique to the fuel rod cladding tube or the arc welding electrode. Is characterized by including a line marker for projecting a line mark.

A fuel rod circumference welding apparatus according to a sixth aspect of the present invention is the fuel rod circumference welding apparatus according to the fourth or fifth aspect, wherein:
The position adjusting means of the arc welding electrode can adjust the tip of the arc welding electrode three-dimensionally.

According to a seventh aspect of the present invention, there is provided a fuel rod circumferential welding apparatus as set forth in any one of the fourth to sixth aspects, wherein the welding condition control means causes the welding condition control means to bring the welding condition close to an optimum value. It is characterized by an adaptive control method that sets welding conditions appropriately.

[0013]

According to the fuel rod circumference welding apparatus of the first aspect of the present invention, the position of the boundary line is determined by the reference position data determining means from the image data taken before the start of the circumference welding by the boundary vicinity image pickup means. After the completion of the circumferential welding, the determination means determines whether the circumferential welding portion is acceptable or unacceptable based on the bead shape image data and the reference position data obtained by imaging the circumferential welding portion by the boundary vicinity imaging means. As a result, even an unskilled worker can quickly and accurately
It is possible to determine whether the circumferential welding is successful or not.

According to the fuel rod circumference welding apparatus of the second aspect of the present invention, the fuel rod cladding pipe movement amount detecting means for measuring the rotation amount and the axial displacement amount of the fuel rod cladding pipe is provided, and the circumference welding is performed. Also, since the axial displacement of the fuel rod cladding tube during the imaging of the circumferential welding portion is detected by using the rotation amount of the fuel rod cladding tube as a parameter, and the reference position data is corrected by this, the reference position data can be corrected. Even if an axial displacement occurs during image capturing of the portion, the displacement can be corrected to improve the accuracy of the pass / fail determination.

According to the fuel rod circumference welding apparatus of the present invention, the reference position data determining means includes a line marker for obliquely projecting a line mark on the fuel rod cladding tube. Can be obtained three-dimensionally.

According to the fuel rod circumference welding apparatus of the fourth aspect of the present invention, the vicinity of the tip of the arc welding electrode is imaged by the welding electrode tip vicinity imaging means, and the arc welding electrode position data determining means is used. Based on the bead shape image data, the reference position data and the arc welding electrode position data, the position of the arc welding electrode imaged by the imaging means near the welding electrode tip part is determined, and the arc welding electrode position data. Optimal values of welding parameters such as position, welding current, welding speed, etc. are determined and welding conditions are adjusted, so that welding conditions can be set quickly and surely. The welding conditions can be changed in accordance with the above conditions, and it is possible to always weld under the optimum welding conditions, and to obtain stable welding quality. Can.

According to the fuel rod circumference welding apparatus of the fifth aspect of the present invention, the arc welding electrode position data determining means includes a line marker for obliquely projecting a line mark on the fuel rod cladding tube or the arc welding electrode. Therefore, the position of the arc welding electrode can be three-dimensionally obtained in the relative relationship with the fuel rod cladding tube.

According to the fuel rod circumference welding apparatus of the sixth aspect of the present invention, the position adjusting means of the arc welding electrode is used,
Since the tip of the arc welding electrode can be adjusted three-dimensionally,
Welding conditions can be set and changed quickly and accurately.

According to the seventh aspect of the fuel rod circumference welding apparatus of the present invention, the welding condition control means is based on an adaptive control system for appropriately setting the welding conditions so as to bring the welding conditions close to the optimum value. Therefore, the welding conditions can be optimized more accurately.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A fuel rod circumference welding apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the overall construction of a fuel rod circumference welding apparatus 1 of this embodiment.

That is, the fuel rod circumferential welding device 1 is for circumferentially welding the fuel rod cladding tube 2 and the end plug 3, and the end rod side of the fuel rod cladding tube 2 to which the end plug 3 is attached is attached. Box-shaped welding chamber 5 into which the end is inserted, and this welding chamber 5
Hold the fuel rod cladding tube 2 inserted in the welding chamber 5 and the arc welding electrode 7 arranged so as to face the boundary line 6 between the fuel rod cladding tube 2 inserted therein and the end plug 3. A rotary chuck (corresponding to the driving means of the invention) 17 for rotating around the axis and a driving roller (corresponding to the moving means of the invention) 8 for moving the fuel rod cladding tube 2 in the axial direction are provided.

As shown in FIGS. 2 and 3, a window 9 is formed through one side wall of the welding chamber 5, and a cover glass plate 14 is fixed to the welding chamber 5 by a fixture 15 so as to cover the window 9. An image pickup means (for example, a CCD camera) that faces the window 9 and images the boundary line 6 between the fuel rod cladding tube 2 and the end plug 3 and the vicinity of the tip of the arc welding electrode 7.
10 are provided. The image pickup means 10 has both the function as the image pickup means near the boundary line of the present invention and the function as the image pickup means near the tip of the welding electrode of the present invention. Separate image pickup means may be provided.

A window 11 is formed on the other side wall sandwiching the fuel rod 4 with respect to the window 9, and a translucent glass plate 16 is attached to cover the window 11. A lamp 12 for a backlight is attached so as to face the window 11.

An illuminating lamp 32 connected to an illuminating power source 21 controlled by a system controller 22 is arranged in the welding chamber 5, and by illuminating the lamp 32 to a required brightness, the welding chamber The interior of 5 is illuminated to facilitate imaging by the imaging means 10. Similarly, the lighting of the lamp 12 is controlled to a required brightness.

In the welding chamber 5, a plurality of linear luminous fluxes are projected toward the arc welding electrode 7 and the fuel rod cladding tube 2 inserted in the welding chamber 5, and the light image (line) thereof is projected. A line marker 33 for displaying a mark) on the arc welding electrode 7 and the fuel rod cladding tube 2 is provided. As shown in FIG. 5, the line marker 33 indicates the positional relationship between the arc welding electrode 7 and the fuel rod cladding tube 2 depending on the positions of the line marks 51 a and 52 a projected on the arc welding electrode 7 and the fuel rod cladding tube 2. It is for three-dimensional determination.

Furthermore, the end plugs 3 are brought into contact with the opposing wall portions of the end plugs 3 of the welding chamber 5, and a contact jig 13 having a function of a positioning stopper is attached to the end plugs 3. The contact jig 13 can rotate with the end plug 3 in contact. Furthermore, in chamber 5,
A rotary chuck 17 is attached to opposite wall portions of the contact jig 13 to restrain the axial movement of the fuel rod cladding tube 2 to drive the fuel rod 4 to rotate. The rotary chuck 17 is drive-controlled by the operation controller 26.

In the vicinity of the chamber 5 (in the drawing, above the fuel rod cladding tube 2 slightly separated from the chamber 5), the fuel rod cladding tube 2 inserted into the chamber 5 moves axially and circumferentially. A cladding tube movement amount detecting means 20 for detecting the amount in a non-contact state is provided. As the cladding tube movement amount detection means 20, for example, one that detects the movement amount and the movement speed by a speckle pattern obtained by irradiating the fuel rod cladding tube 2 with the laser beam 21 is used.

The arc welding electrode 7 is attached to a three-dimensional adjustment table 34 which moves and adjusts the position of the tip portion in the three-dimensional direction. This three-dimensional adjustment table 34 is drive-controlled by the operation control device 26.

As shown in FIG. 1, the fuel rod circumference welding apparatus 1 of the present embodiment is provided with a system controller 22.
An image signal from the image pickup means 10 is input to the system control device 22. Further, the operation control device 26 includes the drive roller 8 and the rotary chuck 17.
And a motor for driving the three-dimensional adjustment table 34 of the arc welding electrode 7. Further, the system control device 22 can read and write data in the auxiliary data memory 27 attached thereto.

A welding power source 23 is connected to the welding electrode 7, and a welding control device 24 for controlling a welding current or the like is attached to the welding power source 23. It is connected to the system controller 22 via a communication line 25.

The system control device 22 and the welding control device 24 have functions corresponding to the reference position data determining means, the arc welding electrode position data determining means, and the welding condition controlling means of the present invention.

Next, the operation of the fuel rod circumference welding apparatus 1 of this embodiment will be described.

First, the driving means 8 is driven to attach the end plug 3 to the tip.
The fuel rod cladding tube 2 loaded with is conveyed toward the chamber 5, the tip is inserted into the chamber 5 and brought into contact with the contact jig 13 to stop. Next, turn on the backlight lamp 12 and the front light lamp 32 at an appropriate brightness,
From the line marker 33 to the line mark, the arc welding electrode 7
Further, the light is obliquely projected onto the fuel rod cladding tube 2 and the image pickup means 10 images the vicinity of the boundary line 6 between the fuel rod cladding tube 2 and the end plug 3.
As a result, the image data 30 as shown in FIG. 5 is obtained. The process of obtaining the image data 30 is performed by the fuel rod cladding tube 2
The arc welding electrode position data relating to the relative positional relationship between the boundary line 6 and the arc welding electrode 7 is equivalent to the reference position data determining means of the present invention for obtaining the reference position data regarding the position of the boundary line between the boundary line 6 and the end plug 6. It corresponds to the arc welding electrode position data determining means of the present invention to be obtained.

When the image data 30 is obtained, the position of the fuel rod cladding tube 2 is confirmed by the cladding tube movement amount detecting means 20. Furthermore, the tip shape of the arc welding electrode 7 is confirmed based on the image data, and the suitability of the arc welding electrode 7 is determined. In addition, the boundary line 6 and the arc obtained by the image data including the position data in the depth direction of the arc welding electrode 7 from the line mark image 51a on the arc welding electrode 7 and the line mark image 52a on the fuel rod cladding tube 2 Based on the data relating to the relative positional relationship with the welding electrode 7, the arc welding electrode 7 is controlled by a control signal from the operation control device 26 so that the position of the arc welding electrode 7 corresponds to the position of the boundary line 6. The three-dimensional adjustment table 34 attached with is driven to move the arc welding electrode 7.

Next, while rotating the fuel rod cladding tube 2 around the axis by the rotary chuck 17, the boundary between the fuel rod cladding tube 2 and the end plug 3 is circumferentially welded by the welding electrode 7. During this circumferential welding, the movement of the fuel rod cladding tube 2 is monitored by the cladding tube movement amount detecting means 20.

Subsequently, while rotating the fuel rod 4 around the axis, the illumination lamp 32 is turned on by the illumination power source 31 to an appropriate brightness to illuminate the circumferentially welded portion, and the peripheral welding portion is imaged by the imaging means 10. Image data 41
To get This image data 41 is composed of a plurality of image data 41a to 41z as shown in FIG. 6, and the imaging interval between them is a strip having a predetermined width vertically with respect to the axis of the fuel rod cladding tube in each image data. It is set so that, when the images in the shape of a circle are successively stitched together with respect to all the image data, the developed image data of the circumferential surface for just one round can be obtained. Then, each image data is labeled by the circumferential movement amount (rotation angle) at the time of imaging detected by the cladding movement amount detecting means 20, and is taken into the auxiliary data memory 27. In the figure, reference numeral 44 indicates a bead welded around the circumference. Even when the circumferential welded portion is imaged, the cladding tube movement amount detecting means 20 monitors and measures the axial and circumferential movements of the fuel rod cladding tube 2.
When the image capturing is completed, the drive roller 8 is driven to eject the fuel rod cladding tube 2 rearward.

A plurality of image data 41 thus obtained
The developed image data 45 or 46 for one round around the bead 44 as shown in FIG. 7 or 8 is obtained from a to 41z. The position of the bead 44 from the bead image 44b of the image data 45 or 46 (the fuel rod cladding tube 2 obtained from the image 30 of FIG. 4)
It is possible to measure the relative position of the boundary line 6 between the end plug 3 and the end plug 3 with respect to the equivalent line 6 ′, the width of the bead 44, the waviness, and the like. If it is confirmed by the cladding tube movement amount detecting means 20 that there is no axial movement of the fuel rod cladding tube during circumferential welding and imaging, the developed image data 45 of FIG. 7 is obtained, When the axial movement of the fuel rod cladding tube 2 is detected, if the developed image is constructed without correcting the movement amount, the developed image data 46 as shown in FIG. 8 is obtained. On the other hand, when the unfolded image is formed, the unfolded image data close to that in FIG. 7 can be obtained by performing correction on the basis of the axial movement amount detected by the cladding tube movement amount detection means 20. Based on the data, the pass / fail judgment of the circumferential welded portion is performed. In this way, since the pass / fail judgment can be automatically made after the circumferential welding, a skilled worker is not required, and the pass / fail judgment can be performed quickly and accurately.

Further, based on the image data and the shape of the welding electrode 7, the welding conditions such as the relative position of the welding electrode 7 with respect to the boundary line 6 are changed, and the welding condition and the welding electrode 7 are changed.
And the relative position information with respect to the boundary line 6 are stored in the auxiliary data memory 27, the next welding of the fuel rod is performed, and the result is fed back to learn the data in the auxiliary memory 27. Fix it. Further, detailed welded data such as metallurgical phase data of the circumferential welded sample having these data may be added. In this way, by gradually correcting the data in the auxiliary data memory 27 by accumulating learning, it is possible to constantly maintain the optimum welding conditions. That is, learning control (adaptive control) is performed by using the previous circumferential welding result as a so-called teacher to control the welding condition to the optimum one.

Further, since the cladding tube movement amount detecting means 20 is provided above the vicinity of the welding chamber 5, there is no hindrance in the handling of the fuel rod cladding tube 2, which is a long object, and also for handling. It is possible to achieve a special effect on the device layout in that the space of can be minimized.

Further, since the cladding pipe movement amount detecting means 20 is provided above the vicinity of the welding chamber 5, the boundary portion 6 to be circumferentially welded and the fuel rod cladding pipe 2 whose movement is detected by the cladding pipe movement detecting means 20. Of the fuel rod cladding tube 2 can be minimized, for example, the influence of thermal expansion of the fuel rod cladding tube 2 due to welding can be minimized, and the amount of movement of the fuel rod cladding tube 2 by the cladding tube movement detecting means 20 can be reduced. The detection can be performed with high accuracy, and thus the pass / fail determination of the circumferential welding can be performed accurately and reliably.

Further, the degree of wear and abnormal deformation of the welding electrode 7 can be determined from the data on the tip shape of the welding electrode 7 obtained from the image data 30. That is, it is possible to prevent occurrence of welding failure by using the consumed welding electrode 7. In addition, when the shape of the welding electrode 7 becomes abnormal or is deformed too much and the position cannot be adjusted, a signal for replacement can be output.

In addition, in the fuel rod circumference welding apparatus of the above embodiment,
As shown in FIG. 9, a displacement gauge 4 for detecting axial movement near the end of the fuel rod cladding tube 2 on the side opposite to the end plug 3 to be welded around.
8 may be additionally provided. In this case, the detection result of the displacement gauge 48 can be added to the detection result of the cladding tube movement detection means 20, and the movement of the fuel rod cladding tube 2 can be detected more accurately and reliably. Further, the displacement meter 48 has an axial movement amount when the surface of the fuel rod cladding tube 2 is a smooth surface where it is difficult to apply the speckle pattern movement detection type cladding tube movement amount detecting means of the above-mentioned embodiment. It can be used as a detection means.

[0044]

As described above, according to the first aspect of the present invention.
According to the fuel rod circumference welding apparatus described, the reference position data fixing means determines the position of the boundary line from the image data taken before the start of the circumference welding by the boundary vicinity image pickup means, and determines after the circumference welding is completed. Since the means determines the pass / fail of the peripheral welded portion based on the bead shape image data obtained by imaging the peripheral welded portion by the boundary vicinity image pickup means and the reference position data, an unskilled worker Even in this case, whether the peripheral welding is successful or not can be determined quickly and accurately.

According to the fuel rod circumference welding apparatus of the second aspect of the present invention, the fuel rod cladding pipe movement amount detecting means for measuring the rotation amount and the axial displacement amount of the fuel rod cladding pipe is provided, and the circumference welding is performed. Also, since the axial displacement of the fuel rod cladding tube during the imaging of the circumferential welding portion is detected by using the rotation amount of the fuel rod cladding tube as a parameter, and the reference position data is corrected by this, the reference position data can be corrected. Even if an axial displacement occurs during image capturing of the portion, the displacement can be corrected to improve the accuracy of the pass / fail determination.

According to the fuel rod circumference welding apparatus of the third aspect of the present invention, since the reference position data determining means includes the line marker for obliquely projecting the line mark on the fuel rod cladding tube, the reference position data is obtained. Can be obtained three-dimensionally.

According to the fuel rod circumference welding apparatus of the fourth aspect of the present invention, the vicinity of the tip end portion of the arc welding electrode is imaged by the welding electrode tip end portion image pickup means, and the arc welding electrode position data determination means is used. Based on the bead shape image data, the reference position data and the arc welding electrode position data, the position of the arc welding electrode imaged by the imaging means near the welding electrode tip part is determined, and the arc welding electrode position data. Optimal values of welding parameters such as position, welding current, welding speed, etc. are determined and welding conditions are adjusted, so that welding conditions can be set quickly and surely. The welding conditions can be changed in accordance with the above conditions, and it is possible to always weld under the optimum welding conditions, and to obtain stable welding quality. Can.

According to the fifth aspect of the present invention, there is provided the fuel rod circumferential welding apparatus, wherein the arc welding electrode position data determining means includes a line marker for obliquely projecting a line mark on the fuel rod cladding tube or the arc welding electrode. Therefore, the position of the arc welding electrode can be three-dimensionally obtained in the relative relationship with the fuel rod cladding tube.

According to the fuel rod circumference welding apparatus of the sixth aspect of the present invention, the position adjusting means of the arc welding electrode allows:
Since the tip of the arc welding electrode can be adjusted three-dimensionally,
Welding conditions can be set and changed quickly and accurately.

According to the fuel rod circumference welding apparatus of the seventh aspect of the present invention, the welding condition control means is based on an adaptive control system for appropriately setting the welding conditions so as to bring the welding conditions close to the optimum value. Therefore, the welding conditions can be optimized more accurately.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing a fuel rod circumference welding apparatus according to an embodiment of the present invention.

FIG. 2 is a view showing a usage state of the fuel rod circumference welding apparatus of FIG.

FIG. 3 is a plan view of FIG. 2;

FIG. 4 is a view showing a usage state of the fuel rod circumference welding apparatus of FIG. 1.

FIG. 5 is a diagram showing image data obtained in the state of FIG.

FIG. 6 is a diagram showing image data obtained in the state of FIG.

FIG. 7 is a diagram showing an example of image data obtained by joining a plurality of image data obtained in FIG.

FIG. 8 is a diagram showing another example of image data obtained by joining a plurality of image data obtained in FIG.

FIG. 9 is a view showing a fuel rod circumference welding apparatus showing another embodiment of the present invention.

[Explanation of symbols]

1 Fuel Rod Circumference Welding Device 2 Fuel Rod Cladding Tube 3 End Plug 4 Fuel Rod 5 Welding Chamber 6 Boundary Line 7 Arc Welding Electrode 8 Driving Roller (Movement Means) 10 Imaging Means (Imaging Means Near Boundary Line, Imaging Near Tip of Welding Electrode) 17) Rotary chuck (driving means) 20 Clad tube movement amount detecting means 22 System control device (reference position data determining means, arc welding electrode position determining means, welding condition control means) 24 Welding control device (welding condition control means) 30 Image data 33 Line marker 41 Image data

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B23K 9/127 508 B 8315-4E 31/00 K

Claims (7)

[Claims] 1. A means for moving a fuel rod cladding tube fitted with an end plug in an axial direction, a welding chamber into which one end of the fuel rod cladding tube is inserted, and a fuel rod cladding inserted in the welding chamber. A fuel rod circumferential welding device comprising: an arc welding electrode arranged so as to face a boundary line with an end plug of a pipe; and a driving means for gripping a fuel rod cladding tube inserted in the chamber and rotating it about an axis. There is a boundary vicinity imaging means for imaging the vicinity of the boundary, and a reference position data finalizing means for finalizing the position of the boundary from the image data taken before the start of circumferential welding by the boundary vicinity imaging means, After the circumferential welding is completed, there is provided determination means for making a pass / fail determination of the circumferential welded portion based on the bead shape image data obtained by imaging the circumferential welded portion by the boundary vicinity image pickup means and the reference position data. This The fuel rods circumferential welding apparatus according to claim. 2. A fuel rod cladding tube movement amount detecting means for measuring the rotation amount and the axial displacement amount of the fuel rod cladding tube is provided, and the axial direction of the fuel rod cladding tube during circumferential welding and during imaging of the circumferential weld portion. 2. The fuel rod circumference welding apparatus according to claim 1, wherein the displacement amount is detected by using the rotation amount of the fuel rod cladding tube as a parameter, and the reference position data is corrected by this. 3. The fuel rod circumference welding apparatus according to claim 1, wherein the reference position data determining means includes a line marker which obliquely projects a line mark on the fuel rod cladding tube. 4. A position adjusting means for the arc welding electrode,
Welding electrode tip vicinity imaging means for imaging the vicinity of the tip of the arc welding electrode, and arc welding electrode position data deciding means for deciding the position of the arc welding electrode imaged by the welding electrode tip vicinity imaging means, Based on the bead shape image data, the reference position data and the arc welding electrode position data, the optimum value of the welding parameters such as the arc welding electrode position, the welding current and the welding speed is determined, and the welding condition control means for adjusting the welding condition is provided. The fuel rod circumference welding apparatus according to any one of claims 1 to 3, wherein 5. The fuel rod circumference welding according to claim 4, wherein the arc welding electrode position data determining means includes a line marker for obliquely projecting a line mark on the fuel rod cladding tube or the arc welding electrode. apparatus. 6. The fuel rod circumference welding apparatus according to claim 4, wherein the position adjusting means of the arc welding electrode is capable of adjusting the tip of the arc welding electrode three-dimensionally. 7. The welding condition control means according to any one of claims 4 to 6, wherein the welding condition control means is based on an adaptive control method for appropriately setting the welding conditions so as to bring the welding conditions close to an optimum value. Fuel rod circumference welding equipment.