JPH0576400B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an apparatus for automatically welding large-sized pipes, and more particularly to the structure of a self-propelled automatic welding apparatus.

<Prior Art and its Problems> Conventionally, when connecting large-diameter pipes, in a factory, a welding device was fixedly positioned and the large-diameter straight pipe was rotated to perform butt welding. Rotating such a large diameter pipe itself requires large-scale equipment, but in addition, when this large pipe is made into a curved pipe, it is necessary to rotate the straight pipe section to be butt welded. If you try to do so, the bent part at the other end will "swing around", and even if you hold the straight part firmly, the force applied to the holding part will change due to the imbalance due to the weight of the bent part depending on the rotational position of the pipe. Unfavorable situations occur in controlling the welding speed. On the other hand, a space is required for the swinging of the bent pipe, resulting in a waste of safety and factory space. For this reason, pipes with bends are not rotated, and are placed on a pedestal and skilled welders can move them up.
Since manual downward welding is repeated, narrow gap welding with an open tip of 10 mm cannot be performed, resulting in problems such as delays in the work process and increased processing costs.

In addition, in large boilers or chemical equipment for power generation, etc., there are many large diameter pipes, and the number of butt welded parts for piping is enormous. In addition, such welding must be performed at a high location on-site in an environment with insufficient scaffolding, and from the standpoint of safety and obtaining high-quality welds, there is a strong desire to realize automatic narrow-gap welding of large-diameter pipes. It is a place.

<Object of the present invention> The present invention has been constructed in view of the above-mentioned problems, and is an apparatus capable of fully automatic welding of large diameter pipes with a narrow gap. Regarding the structure of automatic welding equipment.

<Summary of the present invention> In short, the present invention provides an apparatus for self-propelled and automatic butt welding on the outer periphery of a large-diameter pipe, which includes: a traveling cart with groove guide rollers on which an automatic welding apparatus is placed;
a traction truck located diametrically symmetrically to the traveling truck on the axis of the large-diameter pipe and having approximately the same weight as the traveling truck on which the automatic welding device is mounted; A self-propelled self-propelled device, characterized in that a pair of tension carts of equal weight and located symmetrically about the center are connected to each other by a connecting means that does not contact the outer surface of the large diameter pipe so that these carts can rotate. It is an automatic welding device.

<Summary of technology related to the present invention> In view of the above-mentioned problems, the present inventors have separately proposed a fully automatic narrow gap welding device for large diameter pipes, and the present invention is suitably implemented in this device. It is a device that obtains Therefore, an outline of a separately proposed device will be explained, and then embodiments of the present invention will be explained.

FIG. 3 shows a state in which this device is attached to a large diameter pipe 13 and performs narrow gap welding. The tow truck 15 is disposed at a position symmetrical to the automatic welding device 9 on the axis 14 of the large-diameter pipe 13, and its weight is approximately equal to and balanced with the traveling automatic welding device 9. When this traveling automatic welding device 9 and the traction truck 15 are simply connected by a chain 16, the chain 16 comes into contact with the outer surface of the large-diameter cargo, which not only damages the outer surface of the large-diameter tube but also damages the driving force of the traction truck. make it bigger.

For this purpose, there are two tension carts 17 that apply tension to the chains so that the chains 16 do not come into contact with the outer peripheral surface of the large-diameter pipe.The two tension carts 17 are symmetrical about the axis of the large-diameter tube in the diametrical direction perpendicular to the diameter direction of the pipe that includes the pulling cart and the automatic welding device. and have the same weight so that the resistance to rotational movement of the device of the present invention, that is, the driving force is small.

In the apparatus configured as described above, the entire apparatus moves in the circumferential direction of the large-diameter pipe 13 via the chain 16 by the driving force of the traction cart 15, and this movement causes arc welding (especially
MIG welding) is performed. As described above, in this apparatus, the welding work is not necessarily performed in a place with a favorable working environment such as in a factory, but also in a high place. In this case, the illustrated device must be manually transported to a predetermined location. For this reason, it is preferable that the traveling automatic welding device 9, which is the largest of the devices, be disassembled and easy to carry.

<Example> Examples of the present invention will be described below.

In FIG. 1, the traveling automatic welding device indicated by the reference numeral 9 is constructed so that it can be disassembled into three parts.
Moreover, the three parts are designed to be relatively movable and to be easily attached and detached.

First, reference numeral 20 is a running truck, 21 is a running wheel, 12 is a shaft for this running wheel, and 11 is a guide roller. This guide roller is constructed by placing two disc-shaped roller constituent members in opposing positions, and by inserting and arranging the edge of this disc-shaped member into the groove 22, the traveling carriage 20 can be welded. It is designed to be able to move accurately within the groove in the circumferential direction of the large diameter pipes 13a, 13b. Incidentally, since the traveling carriage 20 is moved by the driving force of the towing carriage 15 via the chain 16, normally no drive device is attached to the traveling carriage itself.

Next, reference numeral 23 indicates a welding head mounting portion.
Reference numeral 24 is an arm for attaching a welding head, and 10 is a threaded rod for raising and lowering the arm. This threaded rod 10 is rotated by a motor (not shown) to raise and lower the arm 24. Reference numeral 8 denotes a drive device for driving a welding wire supply roller (not shown) attached to the welding head 25, and as described later, it is connected to the roller via a shaft and a universal joint to drive it. I have to. Note that since the roller drive device 8 itself is quite heavy, if it is attached to the side of the welding head 25 that has rollers, it will interfere with fine adjustment of the position of the head and there is a risk of degrading the welding quality. The configuration is such that it is placed on the 23 side. The welding head attachment portion 23 is attached to the traveling carriage 20 via a guide groove so that the center of the nozzle is aligned with the center of the groove. Reference numeral 23 indicates a state where it is attached to the trolley 20.

The welding head 25 then has a roller arrangement 5 with guide rollers 5a, whose end 5b is connected to the welding head mounting 23 by attaching it to the arm 24. In this case, the rod 26 attached to the drive device 8 is inserted into the rod 27 on the welding head 25 side for connection. 26
is a key formed on rod 26, and rod 27 is a key formed on rod 26.
It engages with a keyway 27 formed therein. Also 28,
29 is a universal joint, and the installation length of this universal joint and each rod (insertion depth of rod 26 into rod 27)
By making the welding head variable, the driving force of the drive device 8 can be reliably transmitted to the supply roller side of the welding head even when the welding head 25 moves up and down.
Reference numeral 25 indicates the position of the welding head attached to welding head 23. In addition, if the welding head is made to have a mechanism that allows vertical feeding for thick pipes, the weight of the welding head will increase, so the position of the welding head should be placed on the sliding part that is the connection between the arm 24 and the welding head. Knob holes 31a, 31b, 31c, etc., which can be switched vertically in a plurality of stages, are provided on the arm 24 side, and a knob 30 with a spring stop is used to position the welding head with respect to the arm.
The welding head can be easily and automatically fed in the vertical direction according to the bead thickness at each of the knob positions by a set of rods 26 and 27 with universal joints that automatically adjust the length.

FIG. 2 shows the assembled state of the apparatus having the above structure.

<Effects> Since the present invention is configured as described above, the traveling automatic welding device can be divided into a plurality of parts, making it easy to carry, and the device can be easily installed not only in a factory but also in high places. The range of use of the welding equipment can be expanded.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a divided state of the traveling automatic welding device, FIG. 2 is an assembled diagram of the traveling automatic welding device shown in FIG. 1, and FIG. 3 is a side view of the automatic welding device. 8...Roller drive device, 13a, 13b...Large diameter pipe, 20...Traveling trolley, 23...Welding head attachment part, 24...Arm, 25...Welding head, 26, 27...Rod, 28, 29...Universal joint.

Claims (1)

[Claims] 1. In an apparatus for self-propelled and automatic butt welding on the outer periphery of a large diameter pipe, a traveling trolley equipped with a groove guide roller on which an automatic welding device is mounted, and a traveling trolley diametrically symmetrical to the traveling trolley about the axis of the large diameter pipe. a traction cart whose weight is approximately equal to that of the traveling cart on which the automatic welding device is mounted; and a pair of tension carts of equal weight located symmetrically with respect to the axis in a diametrical direction substantially orthogonal to the diametrical direction. , a self-propelled automatic welding device characterized in that these carts are connected so as to be rotatable by a connecting means that does not come into contact with the outer surface of the large diameter pipe.