JPS6116952Y2 - - Google Patents

Description

[Detailed explanation of the idea] When TIG welding a circumferential joint of a steel pipe from the outside,
It is necessary to seal the welded part with inert gas from the inside of the steel pipe, but conventionally, the entire area near the welded part on the inside of the steel pipe to be welded is sealed with a vinyl sheet, etc., leaving only the shield gas supply port, and the back side of the welded part is sealed. After confirming that the pipe was filled with inert gas, welding began.

However, as the inner diameter of the steel pipe to be welded becomes larger, not only does it take longer to create an inert gas atmosphere on the back side of the part to be welded, but also the inert gas is supplied after the sealed interior is evacuated. Otherwise, it would be difficult to create a completely inert gas atmosphere, and moreover, a large amount of inert gas would be consumed.

This proposal relates to the improvement of a welding shield device that overcomes these difficulties.In equipment that performs all-position welding from the outer surface of a circumferential joint of a pipe, the device is supported by a bearing on a cart and slides on the center axis of the pipe. and a rotating shaft to be rotated; a first parallel link mechanism that is connected to the rotating shaft and is sung in the radial direction by the sliding movement of the coaxial shaft; A back shield box is attached to the tip of the parallel link mechanism 1 and forms an inert gas atmosphere in contact with the inner surface of the circumferential joint; a second parallel link mechanism that is sung; a contact piece that is attached to the tip of the second parallel link mechanism and comes into contact with the inner surface of the pipe; a sliding operation mechanism for the rotating shaft; It is characterized by a rotational drive mechanism that rotates the back shield box at the same rotational angular velocity as the welding torch through a parallel link mechanism, and its purpose is to:
An object of the present invention is to provide a device that can reliably shield the inner surface of a welded part of a large-diameter pipe with an inert gas.

As described above, the present invention relates to equipment for welding a circumferential joint of a pipe in all positions from the outside surface, and includes a rotating shaft supported by a bearing on a truck and sliding and rotating on the central axis of the pipe, and a first parallel link mechanism that is connected to and is radially moved by coaxial sliding and rotated around the same axis as the coaxial rotation; a back shield box that is in contact with the inner surface of the circumferential joint to form an inert gas atmosphere; a second parallel link mechanism that is connected to the rotating shaft and is moved in the radial direction by sliding on the same axis; A contact piece attached to the tip of the second parallel link mechanism and in contact with the inner surface of the pipe, a sliding operation mechanism for the rotating shaft, and the back shield box via the first parallel link mechanism. Since a rotary drive mechanism is provided that rotates the back shield box at the same rotational angular velocity as the welding torch, by driving the back shield box with the same rotary drive mechanism, the inner surface of the welded part of the pipe to be welded with the welding torch is inert. It can be sealed with gas to ensure the required welding.

Further, according to the present invention, the back shield box is driven to rotate at the same rotational speed as the welding torch,
Since the inner surface of the welded part of the pipe to be welded by the welding torch is locally sealed with inert gas, the inert gas concentration in the welded part to be welded by the welding torch is extremely high, allowing complete welding. Not only will it be. The amount of inert gas consumed is significantly reduced, and welding costs are significantly reduced.

Furthermore, according to the present invention, since the welding backshield device is disposed on a trolley, it is extremely easy to carry it into the object to be welded, that is, the pipe, place it at the welding point, and move it, and it also has a sliding operation. By simply sliding the rotating shaft in the mechanism, the first parallel link mechanism and the second parallel link mechanism slide simultaneously, causing the back shield box and the contact piece to move in the same way, allowing them to contact and separate from the inner surface of the pipe at the same time. Therefore, even for pipes of different diameters, the backshield box and the detachable piece can be installed and retracted very easily and quickly just by sliding the rotary shaft, and the operational performance is significantly improved.

The present invention will be explained below with reference to the illustrated embodiment.
Reference numeral 1 designates a backshield box having rollers 2 at its four corners, and the backshield box 1 is connected to a saucer 3 by four shafts 4 and compression springs 5.

The tip of an inert gas supply hose 6 is connected to the inside of the back shield box 1, and the other end of the hose 6 is connected to an inert gas source (not shown) through the hollow part of the rotating shaft 10. A curtain 7 is stretched around the outer periphery of the shield box 1 to enhance the shielding effect.

Further, the back shield box 1 is connected to the tip of a rotating shaft 10 via two parallel links 8 and 9, and a slide 11 provided on one of the links 9
A control rod 14 connects the rotary drive shaft 13 to the rotary shaft 10, which is fitted to the rotary shaft 10 by an embedded key 12 so as to be able to slide in the axial direction but not to rotate relatively.

Furthermore, the worm gear 15 is integrally fitted onto the rotary drive shaft 13 via a flat key 16, and the worm 17 meshing with the worm gear 15 is rotationally driven by a motor 18.

A contact switch 20 is disposed opposite to a protrusion 19 protruding from the side surface of the worm gear 15, and the position of the back shield box 1 is determined by operating the switch 20. .

Further, the rotating shaft 10 is rotatably fitted in a bearing 21, and the rotating shaft 10 is rotated so that the worm gear 15, which is fitted to the rotating drive shaft 13 by a washer 22 and a stopper 23, does not come off from the worm 17. Fixed in direction.

Furthermore, the rotating shaft 10 is rotatably fitted in a bearing 24, and both bearings 21 and 24 are formed by support rods 25a and 25b directed downward and a connecting member 26 connected to the lower ends of both support rods 25a and 25b. They are integrally connected to each other, and a movable wheel 27 is pivotally connected to the connecting member 26. A truck is constituted by the support rods, the connecting member, and the movable wheel, and the above-mentioned mechanism is mounted on the truck. The rotary shaft 10 is supported via a bearing so that it can slide and rotate.

Furthermore, a bearing 28 is fitted on the rotating shaft 10 with a stopper 29 so that it does not move in the axial direction but is rotatable, and the bearing 28 and the three contact pieces 30 are connected to three pairs of parallel links 31 and 32 oriented in the radial direction. One link 32 is connected to the bearing 24 by a control rod 33, and the distance L between the base pivot points of one link 32 and the control rod 33 is equal to the distance between one link 9 of the back shield box 1 and the control rod 14. The distance L between the base pivot points is set to be equal to the distance L between the base pivot points.

Moreover, a cylinder 35 is interposed between the projecting piece 34 of the bearing 28 and the supporting piece 25b, and a limit switch 36 is attached to the contact piece 30.

In addition, 37 is a welding torch, and the welding torch 37
is located on the outer periphery of the circumferential joint 39 of the pipes 40, 41 to be welded, and emits a welding arc 38 to perform the required welding.

Since the illustrated embodiment is constructed as described above, when the cylinder 35 is extended (see FIG. 4) or shortened (see FIG. 3), the rotary shaft 10 and the bearing 28 and the rotary drive shaft 13 and the bearing 24 move relatively apart or approach each other, so that the parallel links 8, 9,
As a result, the back shield box 1 and the contact piece 30 are welded to the welded pipes 40 and 4
1 may be separate or in contact.

Therefore, as shown in FIG.
With the pipes 9, 31, and 32 folded, the pipe to be welded 40,
41 and stopped at a preset position using the limit switch 36, then when the cylinder 35 is shortened, the parallel links 8, 9, 31, 3
2 stands up, the contact piece 30 is pressed against the inner surface of the tube to be welded 41, and the rotating shaft 10 is fixed at the center of the tubes to be welded 40, 41 and oriented in the direction of the central axis thereof,
Back shield box 1 is welded pipes 40, 41
It is opposed to the inner circumferential surface of the circumferential joint 39.

In such a state, when the welding arc 38 is emitted from the welding torch 37 and the required welding is started, the rotating shaft 10 and the rotating drive shaft 13 are driven to rotate by the motor 18 at the same rotational angular velocity as the welding torch 37, The back side of the welded part is also sealed by the inert gas atmosphere inside the back shield box 1.
The required welding is performed.

Since the position of the back shield box 1 is detected by the proximity switch 20 and the protrusion 19, the welding torch 37 and the back shield box 1 are
It can always be rotated in a relative position.

As described above, according to the embodiment, the required welding can be performed extremely efficiently within a short period of time.

Also, the cylinder 35 is activated and the moving wheel 2
Just by running 7 inside the pipes 40 and 41 to be welded,
The back shield device can be set up, and the preparation time up to welding is significantly shortened.

Furthermore, since inert gas is locally supplied only to the locations where actual welding is being performed, the amount of inert gas consumed is significantly reduced, resulting in significant cost savings.

Furthermore, even if the pipe diameters of the welded pipes 40, 41 change, it is only necessary to change the stroke of the cylinder 35, so the range of applicable diameters of the welded pipes 40, 41 is extremely wide.

[Brief explanation of the drawing]

FIG. 1 is a partially vertical side view showing an embodiment of the welding backshield device according to the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a side view showing the set state of the embodiment. FIG. 4 is a side view showing the reset state, and FIGS. 5 to 7 are front views showing the welding work state of the embodiment. 1...Back shield box, 2...Roller, 3...Saucer, 4...Shaft, 5...Compression spring, 6
...Inert gas delivery hose, 7...Curtain,
8, 9...Parallel link, 10...Rotation axis, 11...
... Slide, 12 ... Implanted key, 13 ... Rotation drive shaft, 14 ... Control rod, 15 ... Worm gear, 16 ... Flat key, 17 ... Worm, 18 ...
...Motor, 19...Protrusion, 20...Switch,
21...Bearing, 22...Washer, 23...Stopper, 24...Bearing, 25...Support rod, 26...Connecting member, 27...Moving wheel, 28...Bearing, 29
...Stopper, 30...Contact piece, 31, 32...
...Parallel link, 33...Control rod, 34...Protrusion piece,
35...Cylinder, 36...Limit switch, 37...Welding torch, 38...Welding arc,
39...Circumferential joint, 40, 41...Pipe to be welded.

Claims (1)

[Scope of utility model registration request] Regarding equipment for all-position welding from the outer surface of a circumferential joint of a pipe, there is a rotating shaft that is supported by a bearing on a truck and slides and rotates on the central axis of the pipe, and a coaxial a first parallel link mechanism that is slid in a radial direction by sliding and rotated about the same axis as the coaxial rotation;
A back shield box is attached to the tip of the parallel link mechanism and forms an inert gas atmosphere in contact with the inner surface of the circumferential joint, and a back shield box is attached to the rotating shaft and slides in the radial direction by coaxial sliding. second to be done
a parallel link mechanism, a contact piece attached to the tip of the second parallel link mechanism and in contact with the inner surface of the pipe, a sliding operation mechanism for the rotating shaft, and the first parallel link mechanism. A backshield box device for welding, comprising a rotary drive mechanism that rotates the backshield box at the same rotational angular velocity as a welding torch through the welding torch.