JPH0549171U - Metal pipe circumference welding equipment - Google Patents

Abstract

(57) [Summary] [Purpose] In circumferential welding of metal pipes, the prevention of defective shape and oxidation of the inner bead is efficiently performed by a simple device. [Structure] Supports provided upright on both left and right sides of a gantry, a support shaft horizontally supported by each support and provided with a gas passage through an axis, and a cone fixed to the support shafts. A pad, and a line connecting the shaft cores of the support shafts is a straight line, and one of the support shafts can be rotationally driven and the other can move in the shaft core direction. One of the passages has one end opening to the conical surface of the conical pad and the other end communicating with the gas supply port, and the other of the gas passages has one end opening to the conical surface of the conical pad. An end communicates with the gas discharge port, the conical pad is fixed to the facing side of the support shaft, and the facing direction of the support shaft is tapered.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a peripheral welding apparatus for metal pipes, and more particularly to an apparatus capable of preventing a defective shape and oxidation of an inner bead.

[0002]

[Prior Art]

 Circumferential welding of metal pipes, in which two metal pipes are arranged side by side and the end faces of the metal pipes are brought into contact with each other to weld the abutting portions, requires the work of temporarily welding the metal pipes, and also the welding. Since the molten metal in the welded portion is easily melted down, the shape of the weld bead becomes uneven, and the surface of the weld bead oxidizes to generate scale. In particular, it is difficult to remove the scale and protrusions on the inner bead.

[0003] Conventionally, a method of covering the periphery of a metal pipe to be welded with an inert gas and moving the metal pipe and the electrode relatively to each other to melt the welded portion almost at the same time along the entire length thereof and prevent local burn-through. However, it is known, for example, from Japanese Patent Application Laid-Open No. 56-141985. However, this method is not a technique for preventing oxidation of the inner bead and improving the defective shape because the inert gas is supplied to the outer circumference of the metal tube.

Further, a method of holding an inner bead by a thin film made of PVA by inserting a thin film made of PVA into a metal tube and welding with the inert gas sealed in the thin film is disclosed in, for example, JP-A-56- No. 158293. According to this method, it is possible to prevent oxidation of the inner bead and to improve the shape defect, but since there is no positioning means for the metal tubes, temporary welding of the abutting part is required, and a thin film is inserted into the metal tube and inserted. The work of melting and removing the formed thin film is required.

[0005]

[Problems to be solved by the device]

 An object of the present invention is to efficiently position a metal tube by abutting and positioning the metal tubes and preventing the shape defect and oxidation of the inner surface bead by a simple device in the above-described peripheral welding of the metal tube.

[0006]

[Means for Solving the Problems]

 The gist of the present invention which solves the above-mentioned problems is a support body provided upright on both left and right sides of a pedestal, a support shaft horizontally supported by each of the support bodies, and provided with a gas passage through the shaft core. Each of the support shafts has a conical pad that is provided at the end on the opposite side and has a tapered shape in the direction in which the support shafts face each other, and the line connecting the shaft cores of the support shafts is a straight line. One of the support shafts is rotatable and the other is movable in the axial direction, and one of the gas passages has one end open to the conical surface of the conical pad and the other end to a gas. The other end of the support shaft is in communication with the conical pad, and the other end is in communication with the gas discharge port. One of the conical pads is the same as described above. It is characterized in that it is axially supported by the support shaft and the other is fixedly installed on the support shaft. Further, it is preferable that a pair of support rollers be provided on the upper surface of the gantry so as to be movable up and down in a direction of a line connecting the support shafts.

[0007]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. 1 is a front view of the device of the present invention, FIG. 2 is a plan view, and FIGS. 3 and 4 are partially enlarged views (partially sectional views) of FIG.

Supports 2 and 2 are erected on both left and right sides of the gantry 1, and support shafts 3A and 3B are horizontally supported by the supports 2 and 2, respectively. A line L connecting the shaft cores of the support shafts 3A and 3B is a straight line, and the support shaft 3A is screwed and supported by the support body 2 via a screw screw 6. One end of the support shaft 3B is connected to the electric motor 5 via the coupling 4 and can be rotationally driven. A conical pad 8A is rotatably supported at one end of the support shaft 3A, and a conical pad 8B is fixedly provided at one end of the support shaft 3B. Two guide rods 9 and 9 are provided so as to extend between the support shafts 2 and 2, and a slide member 10 fixed to the support shaft 3A is slidably fitted to the guide rods 9 and 9. Has been done. By turning the handle 7, the slide member 10 moves along the guide rods 9 and 9, and the distance between the conical pads 8A and 8B can be adjusted.

Gas passages 11A and 11B are provided inside the support shafts 3A and 3B shown in FIGS. 3 and 4 through the shaft cores. One end of the gas passage 11A is provided at the conical pad opening 8A of the conical pad 8A. The ends communicate with the gas supply ports 12, respectively. One end of the gas passage 11B communicates with the conical surface opening 19B of the conical pad 8B and the other end communicates with the gas discharge port 13. A circumferential groove 20 is provided at the tip of the portion of the support shaft 3A where the screw screw 6 is provided, and a bolt 21 is inserted into the groove 20. Therefore, in the support shaft 3A, the gas supply port 12 does not rotate even if the screw screw 6 rotates.

Reference numeral 14 shown in FIGS. 1 and 2 is a flow rate control valve for controlling the flow rate of the gas discharged from the gas discharge port 13. Rails are laid on the upper surface of the gantry 1. The rails 16 are provided on both sides of the line (L) connecting the support shafts 3A and 3B to the rail 16 and at the same position as the line (L) in a direction parallel to the line (L). A pair of tube support rollers 15 (only one is shown) having a core are provided through a jack 17, and the tube support rollers 15 and 15 can move in the direction of a rail 16 and can be moved up and down by the jack 17. Is.

When performing circumferential welding of metal pipes with this apparatus, the metal pipes P are placed between the conical pads 8 A 1, 8 B by placing the metal pipes on the pipe support rollers 15, 15 and then turning the handle 7. Sandwich with. This makes it possible to position the metal tubes without temporary welding. Next, an inert gas such as Ar gas is supplied from the gas supply port 12 to supply the inert gas into the metal pipe P. The supplied inert gas expels the air inside the metal pipe from the gas outlet 13 to fill the inside of the metal pipe P with the inert gas, and then throttles the flow control valve 14. Next, when the electric motor 5 is driven to rotate the conical pad 8A, the conical pad 8B is rotatable, so that the metal pipe P is rotated.

While rotating the metal tube P at a low speed, the welding torch 18 is brought into contact with the contact portion T to perform welding. At this time, the inside of the metal pipe P is filled with the inert gas, and the inner bead B is cooled by being continuously supplied from the new inert gas supply port 12, and is retained by the inert gas. Therefore, it is possible to prevent the inner bead from burning through and oxidizing.

In the present embodiment, the pair of pipe supporting rollers 15 and 15 for supporting the metal pipe to be circumferentially welded is provided. However, when the metal pipe is lightweight, the pipe holding rollers 15 and 15 may be omitted. it can. Further, the slide member 10 is provided by being supported by the guide rods 9, 9, but when the screw screw 6 is short, the guide rods 9, 9 can be provided by providing the support body 2 in the axial direction of the screw screw. It can be omitted.

[0014]

[Effect of the device]

 According to the device of the present invention, in circumferential welding of metal pipes, the metal pipes are sandwiched by conical pads, the interior of the metal pipes is filled with an inert gas, and the metal pipes are welded while rotating. As a result, it is possible to prevent displacement of the metal tubes, melting of the inner bead, and oxidation. For this reason, it is possible to omit work such as temporary welding of metal pipes, descaling of the inner bead, and cutting, which reduces the time required for welding and cutting the inner bead to about half that of the conventional method. I was able to do it.

[Brief description of drawings]

FIG. 1 is a front view (partially sectional view) showing an embodiment of the device of the present invention.

FIG. 2 is a plan view of FIG.

[Figure 3]

FIG. 4 is an enlarged view (partially sectional view) of one part of FIG.

FIG. 4 is an enlarged view (partially sectional view) of the other part of FIG.

[Explanation of symbols]

1 Stand 2 Support 3 Support Shaft 4 Coupling 5 Electric Motor 6 Screw Screw 7 Handle 8 Conical Pad 9 Guide Rod 10 Slide Member 11 Gas Passage 12 Gas Supply Port 13 Gas Discharge Port 14 Flow Control Valve 15 Pair of Pipe Support Rollers 16 Rail 17 Jack 18 Welding torch 19 Opening of conical surface P Metal tube B Inner bead T Contact part of metal tube

Claims (2)

[Scope of utility model registration request] 1. A support body (2), (2) provided upright on both left and right sides of a pedestal (1), and a gas that is horizontally supported by the support bodies (2), (2) and passes through a shaft core. Passage (11A),
Support shafts (3A) and (3B) provided with (11B),
The support shafts (3A) and (3B) have conical pads (8A) and (8B) that are provided at the end portions on the opposite sides and taper in the direction in which the support shafts face each other. A line L connecting the axes of the shafts (3A) and (3B)
Is a straight line, the support shaft (3A) is movable in the axial direction, the support shaft (3B) is rotatable, and (b) the gas passage (11A) has a conical pad (8A) at one end.
Of the gas passage (11B) is open at the conical surface of the conical pad (8B) and the other end is at the gas outlet (13). (C) The conical pad (8A) is axially supported by the support shaft (3A), and the conical pad (8B) is fixedly mounted on the support shaft (3B). apparatus. 2. A support shaft (3A) on the upper surface of the gantry (1),
The metal pipe circumference welding apparatus according to claim 1, wherein a pair of support rollers (13) are provided so as to be movable up and down so as to be movable in a direction of a line (L) connecting the axes of (3B). .