JP3333314B2 - Method and apparatus for manufacturing welded pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for manufacturing a welded pipe.

[0002]

2. Description of the Related Art TIG (tungsten inert gas) welded stainless steel pipes are welded from the outer surface, and the beads coming out from the inner surface are smoothed by a method such as gas pressure or crushing.

[0003]

However, smooth processing has been difficult due to the size and shape of the bead.
An object of the present invention is to solve the above problems and to provide a method and an apparatus for manufacturing a welded pipe having a smooth inner bead.

[0004]

Means for Solving the Problems To solve the above problems, the configuration of the present invention is as follows. That is, in the first configuration, the first, second, and third members are connected in series by the first and second connecting pins so as to be rotatable relative to each other in a vertical plane, thereby forming a rod-shaped welding torch mounting member. Connecting the second and third members
Part, the second connection pin is provided on one of the members.
The other member is provided with an oblique hole that is inclined with respect to the pipe axis through the second connecting pin, and the first and third members are provided with upper and lower guide rollers and left and right guide rollers. a portion upper is attached to the inner surface welding torch of connecting the gas and water pipes to the inner surface welding torch, wherein
First and second seal packings are respectively provided on the welding torch mounting member on the upstream side and the downstream side in the pipe feeding direction with the torch interposed therebetween, and while the band plate is extended in the horizontal plane from the band plate coil and fed out in the length direction. In the middle of the bending step, the welding torch mounting member is inserted while being guided by the guide roller, and the upstream end of the welding torch mounting member is supported from above, and is fixed at a fixed position. The seam of the strip is welded from above with an outer welding torch , and the seam of the strip is welded from below with the inner welding torch on the upstream or downstream side in the pipe moving direction from the outer welding torch , and the height of the inner welding torch is increased. upon adjusting the of the pivotally mounted lever to the second member about a horizontal axis of the tube axis perpendicular to connect the adjusting rod between the lower end and the third member of the lever, Serial second compression spring between the third member
Attach the adjustment screw near the upper end of the lever.
Operating the adjusting screw to rotate the lever,
Move the adjustment rod to move the third member closer to the second member
And separated by the second connecting pin and the oblique hole.
That is, the second member is moved up and down .

[0005] The second configuration is inserted into the welding tube fed, first, first second, rotatably mutually third member in a vertical plane, the second connection from the tube feeding direction upstream side to the downstream side It is <br/> coupled with a pin, the first, third member, provided in an upper portion of the upper and lower guide rollers and horizontal guide rollers and a welding torch mounted a rod-shaped member provided with a second member of the welding torch mounting member An inner surface welding torch, a gas / water pipe connected to the torch, and an upstream side in a pipe feed direction with the torch interposed therebetween.
It includes first and second seal packings provided on a downstream welding torch support member, and a torch height adjusting unit, wherein the torch height adjusting unit is a boundary between the first member and the second member, A lever rotatably mounted about a horizontal axis perpendicular to the tube axis, a lower end of the lever, an adjustment rod connected to an upstream end of the third member, and a connecting portion between the second and third members In
And the second connection pin provided on one of the members
A second oblique hole inclined to the pipe axis in a plane parallel to the vertical plane including the pipe axis through the second connecting pin, and attached to the other member between the second and third members. Compression spring
If, engages around the upper end of the lever seen including an adjusting screw for pivoting the lever, the lever operates the adjustment screw
And the third rod is moved by moving the adjusting rod.
Is moved toward and away from the second member, and the second connecting pin is
The second member is moved up and down by the oblique holes .

[0006]

The pipe is fed in the line direction, the outer surface of the pipe is welded with the outer welding torch at a fixed position, and the inner surface is welded with the inner welding torch upstream or downstream in the pipe moving direction. The outer and inner welding gases are sealed by the first and second seal packings. When adjusting the height of the torch, turning the adjustment screw rotates the L-shaped lever, moves the adjustment rod, and moves the third member toward and away from the second member. At this time, the second member moves up and down due to the oblique hole, and the torch moves up and down.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to an embodiment shown in the drawings. In FIG. 1, a stainless steel strip is continuously fed in a direction indicated by an arrow while being gradually bent into a cylindrical shape by a forming roll (not shown) to form a steel pipe P. A TIG outer surface welding torch B is installed above the outside of the steel pipe P, and a TIG inner surface welding torch A is provided inside the tube.

In FIGS. 1, 2, 3, and 5, a welding torch mounting member 10 includes first, second, and third members 11, 12, and 13 connected from a first upstream side to a downstream side in a pipe feeding direction. They are connected by a second connecting pin 4b. The support member 10 is long inserted into the pipe P from a part whose upper side is open while the strip is bent into a tubular shape, and is a rod-shaped body as a whole. One of the connecting portions of the first, second, and third members is a convex portion and the other is a groove portion so as to be slidably fitted to each other, and these members can rotate with each other in a vertical plane. I have. The upstream end of the first member 11 becomes a tapered surface 11c, and the support member 41 penetrating the tapered surface 11c extends upward to the outside of the pipe P and is fixed to a location not shown in the drawing. The mounting member 11 and the support member 41 are detachably fixed by the wedge 42 penetrating the tapered surface 11c vertically. The first member 11 includes a main member 11a and a sub-member 11b that are connected in the tube axis direction by a leaf spring 3 that is long on the upper side in the tube axis direction.

An upper and lower guide roller 1 is provided upstream of the main member 11a and the third member 13 in the pipe feed direction, and a left and right guide roller 2 is provided downstream. The upper and lower guide rollers 1 are composed of a plurality (six in the figure) of which a part (four in the figure) rotates in contact with a lower part of the inner surface of the pipe P, and another part (two in the figure) rotates with the upper part of the inner surface. Similarly, a plurality of left and right guide rollers 2 (see FIG. 3)
), A part of which rotates in contact with the left part of the inner surface and the other part rotates in contact with the right part of the inner surface.

3 and 4, an upper portion of the second member 12 is dug, and an intermediate block 32 is removably attached thereto by a screw T1 via an insulating layer 31 of a bakelite plate. The torch block 5 is located above the intermediate block.
Is embedded and detachably attached via the screw T2 and the lock member 6. The boundary surface between the torch block 5 and the lock member 6 becomes inclined surfaces 5a and 6a with the torch block side facing upward and falling to the upstream side, and forms a wedge surface.

An inner surface welding torch (electrode bar) A is detachably attached to the torch block 5. Torch block 5
Is provided with a cylindrical recess 5a on its upper surface, and its peripheral edge becomes an annular raised portion 5c. A well-known collet chuck 33 is screwed into the bottom of the recess 5a.
Is removably attached via a nut 33b.

The intermediate block 32 and the torch block 5
Are provided with a water passage 7a and a gas passage 7b, respectively, and packing is provided at a boundary portion of these blocks to keep watertight. The waterway has an outbound route and a return route. The leading end of the gas passage 7b communicates with a hole at the lower end of the collet chuck 33, and gas comes out from a crack on the side surface of the collet chuck 33. It is formed.

On the upstream side of the second member 12, an inner surface sealing gas nozzle 34 for the outer surface welding torch B is provided. That is, two long gas pipes are provided in parallel with the pipe axis direction with the axis of the second member interposed therebetween, and the gas pipe is provided with a plurality of nozzle holes.

The first seal packing 8a is provided near the upstream end of the second member 12 and in the middle of the third member 13 with the inner surface sealing gas nozzle 34 and the torch block 5 interposed therebetween.
And a second seal packing 8b is provided in airtight contact with the inner surface of the pipe P. These packings are made of rubber or the like integrally formed with a frustoconical cylinder that extends from the cylindrical portion to the downstream side in the pipe feeding direction in order to confine the sealing gas between the first and second packings.

The height of the torch A is adjusted by a torch height adjusting section 20. That is, in FIGS. 2 and 5, the two L-shaped members are in the same posture with the boundary between the first and second members 11 and 12 therebetween, to form the L-shaped lever 21. The lower ends of 21b are connected to each other. And
Align one side 21a in the length direction of the torch mounting member 10,
The pin 22 penetrates the bent portion together with the end of the first member 11 with the other side 21b facing downward. Thus, the lever 21 is rotatable around a horizontal axis perpendicular to the tube axis. And it penetrates the connection part of one side 21a up and down, and the torch attachment member 1
2, a head adjustment screw 23 is screwed. L-shaped lever other side 2
1b to the rear end of the third member 13
Are linked.

The second connecting pin 4b is connected to the second part of the third member 13 .
An oblique hole 25 fixed to the connecting portion with the member 12 and penetrating therethrough is provided at the connecting portion of the second member 12 with the third member 13 . The oblique hole 25 is inclined so as to be higher on the downstream side in the pipe feeding direction. 26 is a compression spring, the second and third members 1
It is attached between 2 and 13 and is urged in a direction to separate them.

The operation state will be described above. Steel pipe P
Is sent in the line direction, the outer surface of the pipe is welded by the outer surface welding torch B at a fixed position, and the inner surface is welded by the inner surface welding torch A downstream of the tube moving direction. The outer and inner welding gases are sealed by the first and second seal packings 8a and 8b. When exchanging the inner surface welding torch A, the feeding of the steel pipe is stopped, and the upper part of the steel pipe is cut into a V-shape when viewed from a direction perpendicular to its axis. Next, the screw T2 is loosened, the lock member 6 is removed, the torch block 5 is taken out, the torch is replaced, and is again put back into the original steel pipe, and the inclined surfaces 5a, 6a
And hold it down. Thereafter, the steel pipe is fed, and welding is performed again from the time when the V-shaped cut portion has passed over the second seal packing 8b. These parts are later cut off as scrap.

When adjusting the height of the torch A, when the adjusting screw 23 is screwed in FIG.
Moves counterclockwise around the center, the adjustment rod 24 moves to the right,
In FIG. 3, the third member 13 is drawn toward the second member 12. At this time , the second member 12 moves upward due to the second connecting pin 4b and the oblique hole 25, and the torch A is raised. To lower the torch A, turning the adjusting screw 23 in the opposite direction causes the third member 13 to move leftward by the force of the compression spring 26, and the second member 12 to move downward, lowering the torch A. .

Since the present invention can be thinned including the torch mounting member 10, the inner diameter is 20 mm to 200 mm or 40 mm or less.
It is particularly effective for small-diameter pipes having a diameter of about 200 to 200 mm, and more preferably about 40 to 100 mm.

The present invention is not limited to the examples and embodiments described above, but includes various modifications without departing from the spirit and scope of the claims.

[0021]

According to the structure of the present invention, a pipe welded from the inner surface can be obtained, and the step of smoothing the inner surface bead can be omitted. In addition, the torch height adjustment part is performed by lever, adjustment screw, adjustment rod, oblique hole, and these are mechanical, so they are strong against the influence of heat and so on, and the accuracy of height adjustment for a long time is improved. I can keep it.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of one embodiment of the present invention.

FIG. 2 is an enlarged view of the right half of FIG. 1;

FIG. 3 is an enlarged view of a left half of FIG. 1;

FIG. 4 is an enlarged vertical axis sectional view near the torch block.

FIG. 5 is an enlarged vertical axis cross-sectional view near a torch height adjustment unit.

[Explanation of symbols]

A: inner surface welding torch B: outer surface welding torch P: steel pipe 1 ... vertical guide roller 2 ... left and right guide roller 3 ... connecting spring 4a ... first connecting pin 4b ... second connecting pin 5 ... torch block 5a ... cylindrical recess 5b ... Gas outlet for sealing 5c Projection 6 Locking means 7a Water path 7b Gas path 8a First seal packing 8b Second seal packing 10 Welding torch mounting member 11 First member 12 Second member 13 Third member 20: Torch height adjusting section 21: L-shaped lever 21a ...
One side 21b ... Other side 22 ... Pin 23 ... Adjustment screw 24 ... Adjustment rod 25
... oblique hole 26 ... compression spring 31 ... insulating layer 32 ... intermediate block 33 ... collet chuck 33a ... body 33b ... nut 34 ... inner surface seal gas nozzle 41 ... support member 42 ... wedge

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI B23K 37/02 B23K 37/02 D (58) Investigated field (Int.Cl. ⁷ , DB name) B21C 37/08 B23K 37 / 00

Claims (2)

(57) [Claims] 1. A first, second, third member in series, the first rotatably to one another in a vertical plane, are bonded through a second connecting pin, constitute a welding torch mounted a rod-like member, the 2nd, 2nd
In the connection part of the three members, one of the members
A connecting pin is provided, and the second member is inserted through the other member.
Then, an oblique hole inclined with respect to the pipe axis is provided,
The upper and lower guide rollers and horizontal guide rollers provided in the third member, is attached to the inner surface welding torch on top of a portion of the second member, to connect the gas and water pipes to the inner surface welding torch, the said welding torch mounting member First and second seal packings are respectively provided on the upstream side and the downstream side in the pipe feeding direction with the torch interposed therebetween, and while the band plate is extended in the horizontal plane from the band coil and fed out in the length direction, gradually formed by the forming roll. Bending in a cylindrical shape, inserting the welding torch mounting member while guiding it to the guide roller in the middle of the bending process, supporting the upstream end of the welding torch mounting member from above, and fixing the band plate with the external welding torch at a fixed position. Weld the seam from above and weld the outer surface
At the upstream or downstream of the torch in the pipe moving direction, a seam of the strip is welded from below with the inner welding torch, and when adjusting the height of the inner welding torch, the second
A lever is attached to the member so as to be rotatable around a horizontal axis perpendicular to the pipe axis, an adjusting rod is connected between the lower end of the lever and the third member, and a compression spring is provided between the second and third members. Taking
The adjustment screw is engaged near the upper end of the lever, and the adjustment screw is operated to rotate the lever, thereby adjusting the adjustment.
Move the rod to move the third member toward and away from the second member
And the second connection pin and the oblique hole form the second connection pin.
A method for manufacturing a welded pipe, wherein a member is moved up and down . 2. The first, second and third members are inserted into a welded pipe to be fed and are rotatably connected to each other in a vertical plane from an upstream side to a downstream side in a pipe feeding direction by first and second connecting pins . A rod-shaped welding torch mounting member provided with upper and lower guide rollers and left and right guide rollers on the first and third members; an inner surface welding torch provided on an upper portion of the second member of the welding torch mounting member; A gas / water pipe connected to the torch, first and second seal packings provided on the upstream and downstream welding torch support members in the pipe feed direction across the torch, and a torch height adjusting unit. The torch height adjustment unit includes a lever rotatably mounted around a horizontal axis perpendicular to the tube axis at a boundary between the first member and the second member, a lower end of the lever, 3 and connected to adjusting rod at the upstream end of member, the first , Communication of the third member
In the joint, the second member provided on one of the members
The second connecting pin is passed through the connecting pin and the other member.
Te, a swash slots oblique to the tube axis in a plane parallel to the vertical plane including the tube axis, is mounted between the second and third members
And a compression spring, engages the upper end vicinity of the lever seen including an adjusting screw for pivoting the lever, thereby rotating the lever by operating the adjusting screw, the adjusting
Moving the rod to move the third member closer to and away from the second member
The second connecting pin and the oblique hole,
An apparatus for manufacturing a welded pipe, wherein two members are moved up and down .