JPS62214876A - Welding method for intersecting body - Google Patents

Abstract

PURPOSE:To enable the welding of the welding position of a welding torch at a flat position from the upper part in vertical direction and to manufacture the intersecting body of good welding quality by welding. CONSTITUTION:The circular arc frame 8 of a positioner is placed on plural rollers 9 and made rotatable with the curvature center as the axis by a motor 11 via a gear 10. A pair of frames 13 supporting both ends of the base pipe 3 of an intersecting body 2 are provided at intervals in the arc direction on the base stand 12 composing the chord of this circular arc frame 8, and the motor 14 rotating the base pipe around the center axis is provided at the other part thereof. Since the weld line with the base pipe can be welded at flat position from the upper part in the vertical direction by the welding torch fitted to the branch pipe 1 with controlling the intersecting body 2 by its rotation around the Z axis by the motor 14 by rotating the intersecting body 2 around X axis by utilizing this positioner, the branch pipe is welded to the base pipe with excellent welding quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method of welding an interdigital body formed by intersecting a main pipe of a large diameter pipe and a branch pipe of a small diameter pipe.

[Prior art and its problems]

Conventionally, welding methods for welding interwoven bodies that are used for offshore structures, etc., and are formed by intersecting the main pipe of a large diameter pipe and the branch pipe of a small diameter pipe, are as follows:
The following are known:

(1) As shown in Fig. 7, the branch pipe 1 is rotated around the axis of the branch pipe 1 to rotate the interpenetrating body 2, in which the branch pipe 1 is positioned horizontally, and the intersection between the branch pipe 1 and the main pipe 3 is formed. The torch 5, which is directed from diagonally above the welding line 4 (which is an intersecting line), is moved forward and backward relative to the main pipe 3, so that the torch 5 is aligned with the welding line 4 that moves due to rotation, and thereby the torch 5 is directed diagonally from above. The welding line 4 is welded around the entire circumference with a torch 5 in a downward posture.

In this method, downward welding is performed, so when a relatively small interdigital body is to be welded, the interdigital body can be welded with good welding quality. However, since only the branch pipes are chucked and rotated, in the case of a large interdigital body, the rotation accuracy becomes unreasonable, resulting in a deterioration of welding quality.

(2) As shown in Fig. 8, a rail 6 is provided around the branch pipe 1 placed horizontally against the horizontally placed main pipe, and the torch 5 is moved by a cart 7 placed on the rail 6. At the same time, the torch 5 is moved forward and backward relative to the main pipe 3, thereby aligning the torch 5 along the welding line 4 and welding only the upper half of the welding line 4.

Next, the interpenetrator 2 is turned upside down, the half circumference of the welding line 4 which was previously on the lower side is placed on the upper side, and this is welded in the same manner as described above.

With this method, it is difficult to position the branch pipe 1 with respect to the main pipe 3, so the groove precision of the weld line 4 is very poor, and the welding position also changes from vertically upward → downward → vertically downward, so welding is difficult. difficult. Therefore, the welding quality is not good. Also, intercorporeal body 2
There is also the difficulty of having to turn large, heavy objects over.

[Object of the Invention] In view of the above-mentioned current situation, the present invention makes it possible to perform welding by changing the welding posture of the torch from vertically upward to downward by controlling the posture of the interdigital body, thus achieving a good welding process. The overall object of the present invention is to provide a method for welding an interdigital body, which can weld an interdigital body with a good welding quality, and which can easily automate the welding.

[Summary of the invention]

The method of welding an interdigital body of the present invention includes a tangent vector of the main pipe on a welding line formed by a reciprocal portion of the interdigital body formed by intersecting a main pipe of a large diameter pipe and a branch pipe of a small diameter pipe, and a tangent vector of the main pipe and the branch pipe of the small diameter pipe. Find a vector passing through the axis of the torch when the torch is positioned so as to point the torch at a predetermined torch angle toward the welding line in a plane including the tangential vector of the pipe, and orthogonally intersect the vector. Determine the rotation angles around each of the two orthogonal axes to rotate around each of the two axes to make a vertical vector, and rotate the interrelated body to each of the two orthogonal axes. The present invention is characterized in that the welding line is rotated by each of the two determined rotation angles, and the welding line is welded by the torch from vertically upward to downward.

[Structure of the invention]

Hereinafter, the welding method of the present invention will be explained in detail based on the drawings.

FIG. 1 is an explanatory diagram showing the principle of the welding method of the present invention. In FIG. 1, 1 is a branch pipe of a translucent body 2, and 3 is a main pipe. To simplify the explanation, branch pipe 1 is the main pipe 3.
is treated as orthogonal to

With the center of the circle of the main pipe 3 on the central axis of the branch pipe 1 as the origin 0, as shown in the figure, the Y axis is in the longitudinal direction of the branch pipe 1, the two axes are in the longitudinal direction of the main pipe 3, and the Y axis is The X-axis is taken in the direction perpendicular to the two axes.

The coordinates eP (χ, y, z) of the point P of the welding line 4 (which is an intersecting line) on the rotational position rotated by an angle ω from the Z axis in the XZ plane including the X axis and the two axes. represent. Also, the tangent vector k t of 40 units of welding line at point P
A ('AT mA+ rLA), also branch pipe 10
The unit tangent vector is tB (LB + 77!B +
nB ), and similarly, the tangent vector of the unit of main tube 3 is tC (
iC+ −C+rLc).

, the coordinates of these points P χ + y + Z, the tangent vector and the cosine of this direction 'A + mA + 9A, etc. are the radius R of the main pipe 3, the radius r of the branch pipe 1, and the rotation of the point P from the Z axis in the XZ plane. Once the angle ω is determined, it can be found through calculation. For example, the coordinates χ, ν, 2 of point P can be found as in the following equation 0, and the tangent vector tA (J-A + mA) of welding line 4 at point P
+ru^) can be found as shown in the following formula 0.

A plane V including the tangent vector tB of the branch pipe 1 and the tangent vector tc of the main pipe 3 is the tangent vector tA of the welding line 4.
is orthogonal to Therefore, as shown in FIG. 2, as long as the torch 5 is positioned so as to aim at the point P within this plane r, the torch 5 is always placed perpendicular to the welding line 4 at the point P. It turns out.

By the way, in FIG. 2, tangent vectors 1B and t.

The angle ψ between the two is a dihedral angle.
e), but in welding interpenetrators, when this dihedral angle ψ is, the bevel angle α (the angle of the notch provided at the intersection of the branch pipe 1 and the main pipe 3) , which is the angle at the notch of the branch pipe 1 with respect to the tangential vector tc of the main pipe 3) is determined by standards such as API and AWS. Then, the torch 5 has this groove angle α
From the viewpoint of welding, the main pipe 3 is positioned so as to aim at a point P by making a certain angle, for example, an angle α/2, with respect to the tangential vector tc of the main pipe 3. Therefore,
Once the dihedral angle ψ is determined, the torch angle ψ, which is the angle between the axis of the torch 5 and the tangent vector tB of the branch pipe 1, is determined. This torch angle ψ is the angle that the torch 5 must take geometrically in order to successfully weld the weld line 4.

However, since the dihedral angle ψ is the angle formed by the tangential vector tB of the branch pipe 1 and the tangential vector tc of the main pipe 3, it can be found from this once the tangential vectors tB and tc are found. On the other hand, as described above, the tangent vectors tB and tc can be determined once the radius r of the branch pipe 1, the radius R of the main pipe 3, and the rotation angle ω of the point P on the weld line 4 are determined. Therefore, when the branch pipe 1 and the main pipe 3 are constant, once the rotation angle ω of the point P is determined, the torch angle ψ can be determined.

Once the torch angle ψ is determined as described above, the unit vector passing through the axis of the torch 5 (hereinafter referred to as the torch vector) t
Q (J-D + rnD + rLD) is obtained as shown in the following equation 0.

Then, as shown in Fig. 3, the torch vector to is
Rotate by 08 around the axis, rotate by 2 around the Z axis, change the torch vector to the vertical torch vector t.
The rotation angle {circle around (2)}8 degrees {circle over (2)} to be p is determined by using the theory of coordinate transformation. This is expressed as the following equation 0.

Therefore, the interpenetrator Zi rotates by 08 around the If it is positioned, it means that the torch 5 has been positioned while ensuring the torch angle ψ. Therefore, if such rotation control of the interdigital body 20 and position control of the torch 5 are performed continuously over the entire circumference of the welding line 4, the torch 5 can maintain the torch angle ψ over the entire circumference of the welding line while maintaining the vertical Welding can be performed from the top to the bottom welding position.

This invention welds interdigitated bodies based on the above principle. In order to carry out the present invention, the following mutual body rotation device and welding device may be used.

FIG. 4 is a conceptual diagram showing a two-axis positioner. In FIG. 4, reference numeral 8 denotes an arc frame of the positioner. The arc frame 8 is placed on a plurality of rows 29, and a motor 11 is connected to the arc frame 8 via a gear 10 that engages with the outer surface of the arc frame 8.
As a result, the arcuate frame 8 rotates around the center of curvature of the arcuate frame 8. A pair of support frames 13 are provided on the base 12 that constitutes the chord of the arcuate frame 8 at intervals in the chord direction for rotatably supporting both ends of the main tube 3 of the interpolator 2. . A motor 14 is provided on one side of the support frame 13 to rotate the interdigital body 2 around the central axis of the main pipe 3.

According to such a positioner, the motor 11 of the arcuate frame 8 rotates the interdigital body 21 by 8 around the x-axis, and the motor 14 of the support frame 13 rotates the interdigital body 2? Since it can be rotated by 2 degrees around the Z axis, it is possible to control the rotation of the interrelated body 20 times as described above.

FIG. 5 is a conceptual diagram showing a welding device installed on a branch pipe of an inter-transparent body. In FIG. 5, 15 is the branch pipe 1 of the phase pipe body 2.
The rails 16 are provided around the rails 15, and numeral 16 is a truck for a welding device placed on the rails 15. The welding device includes a truck 16, a support block 17, a moving block 18, two moving arms 19, and a torch 5. The support block 17 is fixed on the trolley 16 and supports the branch pipe 1.
Support surface 17a extending longitudinally and radially outwardly of
f: Yes. The moving block 18 is the support block 17
is fitted into the guide groove 17b provided in the support surface 17a of the
It is movable in the radial direction of the branch pipe 1. The two moving arms 19 are mounted on the moving block 1 in a direction perpendicular to the moving direction thereof, and are movable in the longitudinal direction of the branch pipe l. The torch 5 is attached to each of the lower ends of two movable arms 19 by a pin 2o, and is movable in the longitudinal direction of the branch pipe 1 by the two movable arms 19, and within a plane including the longitudinal direction and radial direction of the branch pipe 1. It can be rotated freely.

According to such a welding device, even if the attitude of the branch pipe l changes due to the rotation of the interdigital body 2, the branch pipe l of the torch 5 is moved by the movable block 1B while rotating around the branch pipe 1 using the cart 16. By moving the torch 5 in the radial direction, rotating the torch 5 by the two moving arms 19, and moving the branch pipe 1 in the longitudinal direction, the torch 5 is continuously aimed at the welding line 4 from vertically upward to downward. The position can be controlled.

FIG. 6 is a flowchart showing the welding method of the present invention.

As shown in FIG. 6, the reference position (2
The coordinates P(χ.

y, z) e Calculate. Next, the tangent vector tA of the welding line 4 at the point P (J−A + −A r rLA ),
Tangent line vector of branch pipe 1 tB('a + ms +
rLa ), the tangent vector tc ('C
Calculate s −C+ rLc ). Then, the tangent vectors tB and t. Calculate all the dihedral angles ψ. Then, the groove angle α is determined and the torch angle ψ of the torch 5 is calculated.

Next, the torch vector tD (iDo ”
D.

Calculate no>f. Then the torch vector t.

Rotation angle around the X axis and two axes to make it a vertical vector ■8. ■Calculate 2.

Next, ``X'', ``2'', ω, etc. are outputted to control the rotation of the interpolator 20 and the position of the torch 5.

As a result, the torch 5 secures the entire torch angle ψ while
The welding line 4 is welded from vertically upward to point P in a downward posture. And ■8. ■2. After outputting ω, etc., the rotation angle ω that the torch 5 should take is changed to Δ, such as ω=ω+Δω.
By repeating the above calculation while advancing by ω, we obtain the interpolator 2.
0 rotation control, position control of torch 5, t repetition, welding line 4
The torch 5 is used to perform welding over the entire circumference of the weld in a vertically upward-downward position.

In the above embodiment, the branch pipe 1 and the main pipe 3 intersect at right angles, but the present invention is not limited to this. If branch pipe 1 and main pipe 3 intersect diagonally,
All of the above calculations need to be performed in consideration of the intersection angle β (90 degrees), and it is basically the same as when they are orthogonal.

〔Effect of the invention〕

According to this invention, the interdigital bodies can be welded with the torch in a vertically upward to downward welding position while ensuring the torch angle, so that the interdigital bodies can be welded with good welding quality. Moreover, the welding process can be easily automated.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the principle of the welding method of the present invention, FIG. 2 is an explanatory diagram showing the positional relationship of the torch with respect to the welding line, FIG. 3 is an explanatory diagram showing the rotation of the torch vector, and FIG.
The figure shows a two-axis positioner used in the welding method of this invention. FIG. 5 is a conceptual diagram showing a welding device used in the welding method of the present invention, FIG. 6 is a flowchart showing the welding method of the present invention, and FIGS. 7 and 8 are each a conventional welding method. It is an explanatory view showing a welding method. In the drawing, 1.
... branch pipe, 2 ... interdigital body, 3 ... main pipe, 4 ... welding line, 5 ... torch,
8... Arc frame, 13... Support frame, 15... Rail, 16... Trolley
117... Support block, 19... Moving arm.

Claims (1)

[Claims] In a plane including the tangential vector of the main pipe and the tangential vector of the branch pipe on the weld line formed by the intersection of the interdigital body formed by intersecting the main pipe of the large diameter pipe and the branch pipe of the small diameter pipe, When the torch is positioned so that the torch is directed at a predetermined torch angle to the welding line, a vector passing through the axis of the torch is determined, and the vector is rotated around each of two orthogonal axes. Find the rotation angles around each of the two orthogonal axes to make it a vector in the vertical direction, and rotate the interpolator around each of the two orthogonal axes by the two found rotation angles. A method for welding an interpenetral body, characterized in that the welding line is welded by the torch from vertically upward to downward.