JPH0242586B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas shield chamber used in a circumferential automatic welding machine, and in particular, by making the shield plate replaceable, it enables welding with stable quality, and The purpose of this invention is to provide a gas shield chamber that can accommodate changes in dimensions.

As a conventional circumferential automatic welding machine of this type (hereinafter referred to as a "welding machine"), those shown in FIGS. 1a and 1b are known. 1 is a welding head disposed surrounding the outer peripheral surface of the pipe 2;
A drive ring 3 is attached to the front surface (on the left side in the figure) and is rotatably operated by a drive mechanism (not shown) built into the welding head 1. A support plate 5 that fixedly supports a welding torch 4, which will be described later, is fixed to the drive ring 3 with fixing screws 6 and 7. As shown in FIG. 1b, the welding torch 4 is provided with a welding torch adjustment mechanism 9 via an insulating member 8 for adjusting the position of the welding torch 4 at the welding part.
Below the welding torch 4, a nozzle 10 through which shielding gas used during welding is injected and an electrode 11 which serves as an arc generation source during welding are successively installed. Below the nozzle 10, a flat donut-shaped gas shield chamber 12 is arranged perpendicularly to the pipe 2, and is configured to prevent the shield gas injected from the nozzle 10 from diffusing into the atmosphere. There is. The circumferential side surface 12a of the gas shield chamber 12 is divided into three parts in the circumferential direction,
Among them, hinges 12 are provided on both sides of the nozzle 10.
b, 12b, and is attached to a portion facing the peripheral side surface 12a of the nozzle 10, together with a sector-shaped shield plate 12c on the lower side thereof.
It is configured so that it can be opened and closed to the left and right.

Next, the operation of the welding machine having the above configuration will be described. First, the welding head 1 is accurately attached to the pipe 2 to be welded by a centering mechanism (not shown) built into the welding head 1. after that,
When the position of the welding torch 4 is adjusted by the welding torch adjustment mechanism 9 and then the welding machine is energized, an arc is generated between the electrode 11 and the part of the pipe to be welded, and welding is started. At the same time, shielding gas is injected into the welded part through the nozzle 10 to maintain the gas shield chamber 12 in a shielding gas atmosphere and to prevent gas impurities in the atmosphere from entering the welded part, which would have a negative effect on the welded part. It plays a role.

On the other hand, the drive ring 3 attached to the welding head 1 rotates at a constant speed in the circumferential direction of the pipe 2.
The pipe 2 is connected by performing homogeneous welding.

Since the conventional gas shield chamber 12 has the above configuration, as the shield chamber 12 is used repeatedly, the shield plate 12c near the welding part deteriorates due to the heat effect due to welding and moves on the pipe 2. pipe 2 when
It comes into contact with the outer surface and is consumed. As a result, the protective function of the welded portion of the gas shield chamber 12 deteriorates significantly, causing welding defects.

Furthermore, the gas shield chamber 12 has the disadvantage that it can only be applied to pipes 2 of the same size because the pipe insertion hole of the shield plate 12c is formed integrally with the chamber 21 to fit the dimensions of the workpiece. Was.

The present invention has been made to eliminate the above-mentioned drawbacks, and includes an annular gas shield chamber with a groove-shaped cross section that opens inward, and a workpiece that is attached to the surfaces of both outer walls of the shield chamber. a ring-shaped shield plate having an insertion hole for the workpiece adapted to the above, and rings that are stacked on the outside of these shield plates and are removably attached to both outer walls of the shield chamber together with the shield plate; The workpiece insertion hole in the shield chamber and the presser plate is formed to have a larger diameter than the insertion hole in the shield plate, and the shield plate is configured to be replaceable. The present invention aims to provide a gas shield chamber for a circumferential automatic welding machine.

Hereinafter, the present invention will be described based on the embodiments shown in FIGS. 2 and 3, with the same or corresponding parts being designated by the same reference numerals. The gas shield chamber 12 according to this embodiment also has a donut shape like the conventional one, but the nozzle 10 on the gas shield chamber 12
With reference to , a hinge 12b is attached to the circumferential side surface 12a at a position of 90 degrees clockwise, and a latch 12d is attached to a position of 90 degrees counterclockwise to divide the gas shield chamber 12 into two and prevent it from opening downward. It is formed like this.

Separate shield plates 12c are newly arranged on the surfaces of both outer walls of the chamber 12, and these shield plates 12c are also divided into two parts according to the circumferential side surface 12a and attached. . Moreover, in this embodiment, as shown in FIG.
A presser plate 13 is provided on the surface side of 2c, and a plurality of fixing screws 1
4, and the inner diameter of the donut shape of this presser plate 13 is the same as that of the shield plate 12.
These shield plates 12c are formed to have a slightly larger diameter than the inner diameter of the shield plates 12c, and have approximately the same outer diameter.
The holding plate 13 is detachably attached to the chamber 12. The rest of the structure is almost the same as the conventional one.

However, since the shield plate 12c of the gas shield chamber 12 having the above configuration can be easily replaced, the shield plate 12c deteriorates and wears out due to repeated use of a welding machine to which the shield chamber 12 is applied. Even in such a case, by replacing the shield plate 12c with a new one, it is possible to recover the deteriorated shielding performance and perform welding with stable quality. This is particularly effective when welding metals that are highly susceptible to oxidation, such as titanium, for example. By replacing the shield plate 12c according to the frequency of welding work, it is possible to constantly prevent oxygen from entering the atmosphere.
It becomes possible to perform welding work with stable quality.

Furthermore, since the shield plate 12c can be freely replaced, even if the dimensions of the pipe 2 vary, the same shield chamber 12 can be applied as is by simply attaching a shield plate 12c that matches the respective dimensions. It also has the effect of being able to.

As described above, according to the present invention, since the shield plate can be freely replaced, good welding work can always be performed, and it can be commonly used according to changes in the dimensions of the pipe, and the shield plate can be easily replaced. This has the effect of significantly widening the range.

[Brief explanation of the drawing]

Figure 1 is a diagram showing a conventional circumferential automatic welding machine, in which figure a is a side view of the circumferential automatic welding machine, and figure b is a partially broken view of the gas shield chamber on the left side of figure a. 2 is an exploded perspective view of the gas shield chamber according to the embodiment of the present invention, and FIG. 3 is a partially cutaway view of the gas shield chamber of a circumferential automatic welding machine similar to that shown in FIG. 1a. FIG. 12... Gas shield chamber, 12a... Circumferential side, 12c... Shield plate, 13... Presser plate.

Claims (1)

[Claims] 1. An annular gas shield chamber with a groove-shaped cross section that opens inward, and a ring-shaped gas shield chamber that is attached to the surface of both outer walls of this shield chamber and has an insertion hole for the workpiece that is adapted to the workpiece. and a ring-shaped holding plate that is stacked on the outside of these shield plates and is removably attached to both outer walls of the shield chamber together with the shield plate, the shield chamber and the holding plate A gas shield chamber for a circumferential automatic welding machine, characterized in that the workpiece insertion hole is formed to have a larger diameter than the insertion hole of the shield plate, and the shield plate is configured to be replaceable.