JPH0985601A - Repairing the inner surface of welded steel pipe - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] Automating the finishing work of repair welds on the inner surface of steel pipes. SOLUTION: The bead shape of the cross section orthogonal to the axis of the steel pipe of the portion where repair welding is not performed is measured, and the grinding surface of the grindstone is rotated while rotating the grindstone so that the rotation axis is orthogonal to the axis of the steel pipe. In the direction orthogonal to, and about the apex of the bead is rotated about the axis of the steel pipe in a range including at least the width of the bead, the height of the grinding surface of the grindstone at each position in the process of rotating, the height was measured. Grind while moving up and down to the height from the inner surface of the steel pipe that is required from the bead shape, and when grinding of the bead in one cross section orthogonal to the longitudinal direction of the bead is completed, move the grindstone a predetermined distance in the axial direction of the steel pipe. Repeatedly, the bead shape of the cross section orthogonal to the axis of the steel pipe of the repair welded part on the inner surface of the steel pipe becomes almost the same as the bead shape of the cross section orthogonal to the axis of the steel pipe of the welded part that is not repaired. Finishing method for repair welds on the inner surface of welded steel pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention repairs the bead shape of a cross section orthogonal to the axis of the steel pipe of the repaired welded portion after removing the defective portion generated in the welded portion on the inner surface of the welded steel pipe and re-welding the repaired portion. The present invention relates to a method for finishing a repaired welded portion on the inner surface of a welded steel pipe, which finishes the bead shape of a cross section orthogonal to the axis of the welded steel pipe without welding.

[0002]

2. Description of the Related Art When there is a defect in the welded portion of the welded steel pipe inner surface, the defective portion is deleted by a grinder or the like, the groove is adjusted, and the portion is repaired by welding again, and then the steel pipe of the repaired welded portion The finishing process is performed so that the bead shape of the cross section orthogonal to the axis line of is substantially the same as the bead shape of the cross section orthogonal to the axis line of the steel pipe of the welded portion which is not repaired.

Of the series of operations for removing defects generated in the welded portion on the inner surface of the welded steel pipe and appropriately finishing the bead shape after repairing the weld, a method for removing the defects and shaping the groove is described in, for example, There is one proposed in Japanese Patent Application No. 5-263556, and by this method, the removal of defects and the shaping of the groove are automated.

Further, as a method of properly finishing the bead shape, a method of grinding the welding bead of the butt-welding portion of a flat plate to a constant height along the welding line is disclosed in Japanese Patent Laid-Open No. 63-13.
9653, JP-A-63-207554, JP-A-63.
It is disclosed in each publication of JP-A-221963, and these automate the bead finishing operation in the welding of flat plates.

However, the method of finishing the bead of the repair welded portion on the inner surface of the welded steel pipe to a predetermined cross section is not automated, and is performed manually.

[0006]

When it is attempted to automate the work of finishing the bead of the repair welded portion on the inner surface of the welded steel pipe into a predetermined cross section, that is, the bead shape of the cross section orthogonal to the axis of the steel pipe of the repair welded portion is repaired and welded. If you try to automate the work of finishing the bead shape of the cross section that is orthogonal to the axis of the steel pipe of the part that you do not want to automate, the finishing work done manually is complicated by the movement of the grinder. There is a problem. That is, if it is attempted to mechanize the movement of the grinder as it is by manual work, it is difficult from the standpoint of space for a device to enter a steel pipe having a diameter of about 16 inches, for example.

It is an object of the present invention to provide a method for finishing a repaired welded portion on the inner surface of a welded steel pipe which can automate bead finishing work even in a narrow space because the movement of the grinder is simplified.

[0008]

A first method for finishing a repair welded portion on the inner surface of a welded steel pipe according to the present invention is a steel pipe for a repaired welded portion obtained by temporarily removing defective portions of the welded portion on the inner surface of the welded steel pipe and then re-welding. A method of finishing a welded portion on the inner surface of a welded steel pipe, in which the bead shape of the cross section orthogonal to the axis of is welded to the same shape as the bead shape of the cross section orthogonal to the axis of the steel pipe where repair welding is not performed. Measure the bead shape of the cross section orthogonal to the axis of the steel pipe of the part which is not welded, (2) while rotating the grindstone so that the rotation axis is orthogonal to the axis of the steel pipe, (3) the grinding surface of the grindstone Rotate in a direction orthogonal to the axis and around the axis of the bead about the axis of the steel pipe in a range including at least the width of the bead, and (4) adjust the height of the grinding surface of the grindstone at each position in the rotating process. , The measured bead Grinding while moving up and down to the height from the inner surface of the steel pipe that is obtained from the shape, and (5) When grinding of the bead on one cross section orthogonal to the longitudinal direction of the bead is completed, move the grindstone a predetermined distance in the axial direction of the steel pipe. By repeating the above, the bead shape of the cross section orthogonal to the axis of the steel pipe of the repair welded part on the inner surface of the welded steel pipe becomes approximately the same as the bead shape of the cross section orthogonal to the axis of the steel pipe of the welded part that is not repaired. Is to be finished.

When the bead shape of the cross section orthogonal to the axis of the steel pipe of the repair welded portion on the inner surface of the welded steel pipe is finished to be substantially the same as the bead shape of the cross section orthogonal to the axis of the steel pipe of the portion not subjected to repair welding, While reciprocating the grindstone in the orthogonal direction, the vertical height of the grinding surface of the grindstone at each position in the direction orthogonal to the axis of the steel pipe was measured in advance, and the bead of the cross section orthogonal to the axis of the steel pipe in the part where repair welding was not performed Since the grinding is performed while controlling so as to have the same shape, it is possible to minimize the vertical movement distance of the grindstone.

Therefore, the device for finishing can be made compact, and the finishing work of the bead of the repair welding portion can be performed.
It can be automated.

The second method for finishing the repair welded portion on the inner surface of the welded steel pipe according to the present invention is such that the defective portion of the welded portion on the inner surface of the welded steel pipe is once removed and then re-welded. A method for finishing a repair welded portion on the inner surface of a steel pipe that finishes the bead shape of the cross section to be repaired to be substantially the same as the bead shape of the cross section orthogonal to the axis of the steel pipe of the part where repair welding is not performed. Measure the bead shape of the cross-section orthogonal to the axis of the steel pipe, and (2) grindstone with the rotation axis parallel to the axis of the steel pipe except at the skirt of the bead and tilted to the left and right from the axis of the steel pipe at the skirt of the bead. And the height of the grinding surface of the grindstone is maintained at the height from the inner surface of the steel pipe obtained from the measured bead shape corresponding to the position in the direction orthogonal to the axis of the steel pipe to be ground. Along the bead Grinding was performed while moving the length of the bead, and (4) When grinding in the longitudinal direction of the bead at the same position in the direction orthogonal to the axis of the steel pipe was completed, the grindstone was rotated around the axis of the steel pipe by a certain angle. After that, the height of the grinding surface of the grindstone at that position is adjusted to be the height from the inner surface of the steel pipe obtained from the measured bead shape, and then the bead is moved while moving the grindstone in the opposite direction to the above. While repeating grinding for the length of the welded pipe, the bead shape of the cross section orthogonal to the axis of the steel pipe of the repair weld on the inner surface of the welded steel pipe is approximately the same as the bead shape of the cross section orthogonal to the axis of the steel pipe of the weld not repaired. The finish is the same.

Also in this invention, as in the above-mentioned first invention, the device for finishing can be made compact, and the finishing work of the bead of the repair welding portion can be automated.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A method for finishing a repair welded portion on an inner surface of a welded steel pipe according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory view showing a cross section in the longitudinal direction of a finishing device used for finishing the repair welded portion, FIG.
1A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is a line B- of FIG.
3B to 3C are explanatory views showing the movement of the grindstone.

The finishing device used for finishing the repair welded portion is composed of a traveling portion 1 and a grinding portion 21. The running unit 1 has a drum-shaped running unit body 2, drive wheels 3 and driven wheels 4 for running the running unit body 2 in the longitudinal direction of the steel pipe 101, and the running unit body 2 does not run during grinding. Further, it is composed of a fixing air cylinder 5 which is brought into contact with the inner surface of the steel pipe 101, and a rotating shaft 6 which is located at the center of the traveling portion main body 2 and whose axis coincides with the axis of the steel pipe 101.

The movement of the rotating shaft 6 described above will be explained. By rotating the spline 8 with the rotating motor 7 provided in the traveling main body 2, the pinion 9 mounted so as to be movable in the longitudinal direction of the spline 8. Rotates, and pinion 9
By rotating the gear 10 meshing with the rotary shaft 6, the rotary shaft 6 to which the gear 10 is fixed rotates around its axis. Here, the rotation means that the shaft rotates by a predetermined angle, while the rotation means that the shaft rotates many times, and both are properly used.

Further, by rotating the screw shaft 12 with the forward / backward moving motor 11 also provided in the traveling portion main body 2, the screw nut 13 meshed with the screw shaft 12 is moved forward / backward in the axial direction of the steel pipe 101. Since the screw nut 13 is fitted in the collar portion 6a of the rotating shaft 6, the rotating shaft 6 moves back and forth in the axial direction of the steel pipe 101.

The grinding unit 21 has an L-shaped cross-section grinding head 22.
A grinder 24 having a grindstone 23 provided so as to be suspended downward from the horizontal member 22a of the grinding head 22, a grinder driving motor 25 provided on the upper part of the horizontal member 22a, the grinding head 22 and The rotation shaft 6 is provided with a screw nut 26 provided at the shaft end of the rotation shaft 6.
Screw shaft 27 that is connected via a screw shaft 27, a lifting motor 28 that rotates the screw shaft 27 to move the grinding head 22 up and down, a bead shape shooting camera 29 provided on the vertical member 22b of the grinding head 22, and shooting. It is composed of a lighting unit 30, a shooting camera protection air blowing nozzle 31, and a bead height detection sensor 32 for detecting the bead height.

The bead shape photographing camera 29, the photographing illumination 30, the photographing camera protection air blowing nozzle 3
1 is used for bead monitoring,
It is not directly related to the present invention.

Next, using the above-mentioned finishing device, the bead shape of the cross section orthogonal to the axis of the steel pipe of the repair welded portion of the inner surface of the steel pipe is changed to the bead shape of the cross section orthogonal to the axis of the steel pipe of the welded portion not repaired. The method of finishing so as to be substantially the same as the above will be described.

(1) While rotating the rotating motor 7 to rotate the rotating shaft 6 around the shaft core, the bead height detection sensor 32 causes the shaft line of the steel pipe 101 of the welded portion not to be repaired. The shape of the bead 41 in the cross section orthogonal to each other is measured.

(2) Next, as shown in FIG. 3 (a), the rotary shaft of the grindstone 23 is supported so as to be orthogonal to the longitudinal direction of the bead 42 of the repair welding portion, and is driven to rotate, and is rotated. The moving motor 7 is rotated to rotate the rotating shaft 6 around the axis.

(3) At the same time, the elevating motor 28 is driven to rotate the screw shaft 27 and elevate the grinding head 22 to move the grinding head 22 up and down at each position in the direction orthogonal to the axis of the steel pipe 101. The bead shape after the vertical height is adjusted and ground is the measured bead 4
Match the shape of 1.

By doing so, the bead 42 of the cross section orthogonal to the longitudinal direction of the repair weld is ground to have the same shape as the bead 41 of the weld not repaired.

(4) Next, the forward / backward moving motor 11 rotates the screw shaft 12 to move the rotating shaft 6 by a predetermined distance, and the operations of the above items (2) and (3) are performed by the steel pipe 101.
By performing from the opposite side in the direction orthogonal to, another cross-section different from the above is ground.

As a method of moving the rotating shaft 6 by a predetermined distance, it may be moved stepwise as shown in FIG. 3 (b), or as shown in FIG. 3 (c). You may move in a zigzag shape.

As a method of controlling the grinding amount, for example, while controlling the height of the grindstone 23 to the measured bead height, the load current of the grinder 24 becomes a constant value.
There is a method of controlling the speed at which the grindstone 23 is rotated in a direction orthogonal to the axis of the steel pipe 101.

As the grindstone 23 to be used, as shown in the perspective view of FIG. 4, a grindstone disk in which a large number of abrasives 23a are radially laminated around a rotation axis is used.

This is intended to make the finished surface smooth by imparting elasticity to the grindstone disk.

Next, a method of finishing the repair welded portion on the inner surface of the welded steel pipe according to the second embodiment of the present invention using the above-mentioned finishing device will be described with reference to FIG.

(1) While rotating the rotating motor 7 to rotate the rotating shaft 6 around the shaft core, the bead height detection sensor 32 causes the shaft line of the steel pipe 101 of the welded portion not to be repaired. The shape of the bead 41 in the cross section orthogonal to each other is measured.

(2) Next, as shown in FIG. 5A, the axis of rotation of the grindstone 23 is parallel to the longitudinal direction of the bead 42 of the repair weld, or as shown in FIG. 5B. like,
The shaft of the steel pipe 101 of the bead 42 that starts grinding by tilting to the left and right to rotate and drive, and driving the lifting motor 28 to rotate the screw shaft 27 and lift and lower the grinding head 22. The height of the grinding surface of the grindstone 23 at the position in the orthogonal direction is maintained at the measured height of the bead 41.

(3) Then, the forward / backward moving motor 11 rotates the screw shaft 12 to move the rotating shaft 6 in one direction, and grinding is performed for the length of the bead 42.

(4) Next, after rotating the rotating motor 7 to rotate the rotating shaft 6 around the axis by a predetermined angle, the height of the grinding surface of the grindstone 23 at that position is After adjusting the height of the bead 41 to be measured, the screw shaft 12 is rotated by the forward / rearward traveling motor 11, and the rotation shaft 6 is moved in the direction opposite to the case of the item (3). Meanwhile, grinding is performed for the length of the bead 42.

(5) As described above, the rotating shaft 6 is attached to the bead 42.
The bead 42 is finished into the shape of the bead 41 by grinding while reciprocating by the length of, and rotating the rotating shaft 6 by a certain angle each time the moving direction changes.

At the time of finishing the skirt portion 42a of the bead 42, the rotational direction of the grindstone 23 is tilted to the left and right from the width direction of the bead 42 to prevent the bead from being over-cut.

Further, as a method of moving the grindstone 23, as shown in FIG.
As shown in FIG. 5C, the shape may be stepwise, or as shown in FIG. 5D, the shape may be zigzag.

[0037]

According to the present invention, the beading of the repair weld portion on the inner surface of the welded steel pipe can be automatically finished.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a cross section in a longitudinal direction of a finishing device used for finishing work of a repair welded portion on an inner surface of a welded steel pipe.

2A is a sectional view taken along the line AA of FIG. 1, and FIG. 2B is a sectional view taken along the line BB of FIG.

3A to 3C are explanatory views showing the movement of the grindstone in the first embodiment.

FIG. 4 is a perspective view showing the structure of a grindstone.

5A to 5D are explanatory views showing the movement of the grindstone in the second embodiment.

[Explanation of symbols]

 1 Traveling Section 2 Traveling Section Main Body 3 Drive Wheel 4 Driven Wheel 5 Fixing Air Cylinder 6 Rotating Shaft 7 Rotating Motor 8 Spline 9 Pinion 10 Gear 11 Forward / Reverse Motor 12 Screw Shaft 13 Screw Nut 21 Grinding Section 22 Grinding Head 23 Grindstone 24 Grinder 25 Grinder drive motor 26 Screw nut 27 Screw shaft 28 Lifting motor 29 Bead shape shooting camera 30 Shooting lighting 31 Air blow nozzle 32 Bead height detection sensor

Claims (2)

[Claims] 1. A bead shape of a cross section orthogonal to the axis of the steel pipe of the repair welded portion after the defective portion of the welded portion on the inner surface of the steel pipe is once removed and then re-welded, and a cross section orthogonal to the axis of the steel pipe of the portion where the repair welding is not performed. Is a method of finishing the repair welded part of the inner surface of the welded steel pipe that is finished to be almost the same as the bead shape of (1) measuring the bead shape of the cross section orthogonal to the axis of the steel pipe of the part where repair welding is not performed, (2) rotating shaft While rotating the grindstone so that is perpendicular to the axis of the steel pipe, (3) at least the width of the bead around the axis of the steel pipe with the grinding surface of the grindstone in the direction orthogonal to the axis of the steel pipe and with the apex of the bead as the center. In the process of rotating (4), the height of the grinding surface of the grindstone at each position is raised and lowered so as to be the height from the inner surface of the steel pipe obtained from the measured bead shape. , (5) Bee When the bead grinding on one cross section orthogonal to the longitudinal direction of the welded pipe is completed, the grindstone is repeatedly moved in the axial direction of the steel pipe for a predetermined distance to make it orthogonal to the steel pipe axis of the repair welded part on the inner surface of the welded steel pipe. A method of finishing a repair welded portion on the inner surface of a welded steel pipe, characterized in that the bead shape of the cross section is finished so as to be substantially the same as the bead shape of the cross section orthogonal to the axis of the steel pipe of the welded portion that is not repaired. 2. The bead shape of the cross section orthogonal to the axis of the steel pipe of the repair welded portion after the defective portion of the welded portion on the inner surface of the steel pipe is once removed and then re-welded is cross-section orthogonal to the axis of the steel pipe of the portion where the repair welding is not performed. Is a method of finishing the repair welded part of the inner surface of the welded steel pipe that is finished to be almost the same as the bead shape of (1) measuring the bead shape of the cross section orthogonal to the axis of the steel pipe of the part where repair welding is not performed, (2) rotating shaft Is parallel to the axis of the steel pipe except at the skirt of the bead, and at the skirt of the bead, the grindstone is rotated while tilted to the left and right from the axis of the steel pipe, and the height of the grinding surface of the grindstone is the axis of the steel pipe to be ground. Hold at the height from the inner surface of the steel pipe, which is determined from the measured bead shape corresponding to the position in the orthogonal direction, and (3) move in the axial direction by the axial length of the bead along the bead obtained by repair welding the grindstone. Grinding while letting (4) When grinding of the bead in the axial direction at the same position in the direction orthogonal to the axis of the steel pipe is completed, the grindstone is rotated around the axis of the steel pipe by a certain angle, and then the grinding surface of the grindstone at that position is rotated. The height of the bead is adjusted to be the height from the inner surface of the steel pipe obtained from the measured bead shape, and then while the grindstone is moved in the opposite direction to the above, it is possible to grind only the length of the bead. Repeatingly repeating, the bead shape of the cross section orthogonal to the axis of the steel pipe of the repair weld on the inner surface of the welded steel pipe is finished to be almost the same as the bead shape of the cross section orthogonal to the axis of the steel pipe of the weld not repaired. Finishing method for repair welds on the inner surface of welded steel pipe.