JP3466268B2 - Welded pipe manufacturing equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a welded pipe. 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. However, smooth processing has been difficult due to the size and shape of the beads.
An object of the present invention is to solve the above problems and provide an apparatus for manufacturing a welded pipe having a smooth inner bead. [0004] In order to solve the above problems, the configuration of the present invention is as follows. That is, inserted into the welded pipe to be sent, from the pipe feed direction upstream to downstream,
A rod-shaped welding torch mounting member in which first, second, and third members are rotatably pin-connected to each other in a vertical plane, and a first member and a third member are provided with upper and lower guide rollers and left and right guide rollers. A leaf spring for connecting a main member and a sub-member constituting the first member in series on an upper side, an inner surface welding torch provided on an upper portion of a second member of the welding torch support member, and connected to the torch. Gas and water pipes, and first and second seal packings provided on the welding torch mounting members on the upstream and downstream sides in the pipe feed direction with the torch interposed therebetween. [0005] The pipe is fed in the line direction, the outer surface of the pipe is welded by the outer welding torch at a fixed position, and the inner surface is welded by the inner welding torch upstream or downstream of the pipe moving direction. The outer and inner welding gases are sealed by the first and second seal packings. An embodiment 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 has first, second, and third members 11, 12, and 13 connected from a first connecting pin 4a to a downstream from 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. The upper and lower guide rollers 1 are provided upstream of the main member 11a and the third member 13 in the pipe feed direction, and the left and right guide rollers 2 are 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. An internal sealing gas nozzle 34 for an external welding torch B is provided above and upstream of the second member 12. 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 fixed to the third member 13, and an oblique hole 25 penetrating therethrough is provided in the second member 12. The oblique hole 25 is inclined so as to be higher on the downstream side in the pipe feeding direction. A compression spring 26 is attached between the second and third members 12 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. To adjust the height of the torch A, when the adjusting screw 23 is screwed in, the L-shaped lever 21 moves counterclockwise around the pin 22, the adjusting rod 24 moves rightward, and the third member 13 moves It is drawn to the two members 12 side. At this time, the second member 12 moves upward due to the oblique hole 25, and the torch A
Will be higher. To lower the torch A, the adjustment screw 23 is turned in the opposite direction, and the third member 1 is turned by the force of the compression spring 26.
3 moves to the left, the second member 12 moves downward, and the torch A lowers. 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.
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. 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. Further, since the torch support member is composed of three members, the swing can be prevented by attaching the upper and lower guide rollers and the left and right guide rollers. Since the three members are pin-connected, there is flexibility in the axial direction, and the positioning between the second member and the tube can be ensured. The unreasonable external force of the first and third members can escape. Since the main member and the sub member of the first member are connected by the leaf spring 3, vibration can be absorbed.

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. 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. [Description of Signs] A: internal welding torch, B: external welding torch P: steel pipe 1, upper and lower guide rollers 2, left and right guide rollers 3, connection spring 4a, first connection pin 4b, second connection pin 5, torch block 5a ... Cylindrical recess 5b ... gas outlet for sealing 5c ... raised part 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 part 21. L-shaped lever 21 a. One side 21 b.
... 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

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23K 9/025 B23K 9/02 B23K 37/02 301 B21C 37/08

Claims (1)

(1) The first, second, and third members are inserted into a welded pipe to be fed, and are rotatable relative to each other in a vertical plane from an upstream side to a downstream side in a pipe feeding direction. A rod-shaped welding torch mounting member in which a first member and a third member are provided with upper and lower guide rollers and left and right guide rollers, and a main member and a sub member constituting the first member are connected in series on the upper side. A leaf spring connected to the second member of the welding torch support member; a gas / water pipe connected to the torch; and an upstream side in a pipe feed direction with the torch interposed therebetween. And a first and a second seal packing provided on a downstream welding torch mounting member.