JPS6110874Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is an automatic method for relatively thin plates (4.5 to 12 mm) such as bottom plates and roof plates of tanks such as LNG and LPG.
The present invention relates to a backing jig for automatic one-sided welding when performing one-sided butt welding using TIG welding or submerged arc welding. Conventionally, a lap fillet joint structure has been used for this type of tank, but we have improved the safety of welded joints,
Butt welded structures have been adopted from the standpoint of improving quality. However, in this case, when welding thin plates (4.5 to 12 mm thick) such as tank bottom plates and roofs, welding deformations or distortions of various sizes and waves occur, but with conventional backing metal jigs, plate deformation However, there is a drawback that the adhesion of the backing metal against distortion is insufficient, making it impossible to obtain a uniformly high-quality Uranami weld bead. The present invention has been made for the purpose of solving the above-mentioned drawbacks and providing a backing metal jig for single-sided automatic welding that allows the backing metal to adhere well even if the welding base material is deformed. However, the major axis of the arc pool is 3 to 6.
A plurality of strip-shaped backing metals set to double the length, and a backing metal mounting plate that is arranged on the back side of each backing metal via a supporting member and set to approximately the same length as the backing metal. and an elongated holding member that supports the backing metal in a line in the longitudinal direction via the backing metal mounting plate, and disposed between the backing metal mounting plate and the inner wall surface of the holding member facing the mounting plate. The invention is characterized by comprising a compressible member that presses each backing metal to the front side of the backing metal via each backing metal mounting plate and a support member. Embodiments of the present invention will be described below with reference to the accompanying drawings. In FIGS. 1 to 3, 1 is a backing made of copper as an example, 2 is a holding member, and each backing 1
is attached to the backing metal mounting plate 5 of the holding member 2 using four countersunk screws 4 via a spacer 3 in a substantially parallel manner with an appropriate gap a between them. The idea of the present invention is to divide the length l of each backing metal 1 into lengths approximately corresponding to the heat deformation section during welding, and to separate each backing metal 1 into a holding member 2 for each backing metal. It supports the metal in a flexible manner in the thickness direction, and if this thermal deformation section is replaced by the size of the heat source (longer diameter of the arc pool), for example, if the base material is 4.5 to 12 mm thick, the arc pool
It needs to be 6 to 3 times larger than 20 to 40 mm, that is, a maximum of 125 mm. These backing metals 1 are provided with appropriate gaps c between adjacent backing metals 1 so that they can thermally expand freely in the longitudinal direction. A gap d is similarly provided between the backing metal mounting plates 5. It is convenient for handling when four to five backing metals 1 are attached to the holding member 2 in a row. The one shown has four backing metals attached, and their length is 496 mm. As shown in FIG. 3, the holding member 2 has a channel-shaped cross section, and accommodates the aforementioned backing metal mounting plate 5, neoprene rubber 7, and sponge rubber 8 therein.
The channel end of the holding member 2 has a flange portion 9 bent inward, and the flange 9 is pressed against the backing metal mounting plate 5 by the aforementioned neoprene rubber 7 and sponge rubber 8 compressed and stored. and hold it so that it can slide. The dimensions of each part of the backing metal jig 10 shown in FIGS. 1 to 3 are as shown in Table 1, and the total weight is approximately 4.3 kg. As mentioned above, each backing metal 1 has a total length set to 3 to 6 times the size of the heat source (long axis of the arc pool), and each backing metal 1 is attached to a thin plate through the backing metal mounting plate 5. The backing metal mounting plate 5 is supported by a flat, box-shaped holding member 2 made of (2 mm) with a gap c in the longitudinal direction, and the backing metal mounting plate 5 is made of compressible neoprene rubber 7 and sponge rubber 8. Furthermore, as will be described later, since these compression members are set in a compressed state during use, each backing metal 1 is supported within the holding member 2 in the thickness direction of the backing metal. It can extend and contract and can be angularly displaced at different angles from each other. Therefore, each backing metal 1 follows the thermal deformation of the base metal 13 and comes into close contact with the base metal 13 along the welding line e. Note that the holding member 2 is elastically deformed in a plane perpendicular to the base material 13 including the weld line e, but when attaching the jig to the base material as described later, it is necessary to compress the neoprene rubber 7 and the sponge rubber 8 sufficiently. It has rigidity. To attach the backing metal jig of this invention to the base material,
As shown in FIG. 4, a glass fiber backing 11 is applied along the welding line e, the backing metal 1 is placed on this, and the backing metal 1 is attached to the base material 13 using a magnetic clamp 12 and a push bolt 15. At this time, the sponge rubber 8 or the like is compressed through the holding member 2 using the push bolt 15 to create an appropriate gap between the flange 9 and the backing metal mounting plate 5 as shown in FIG. The metal 1 is set so that it can expand and contract relative to the holding member 2 in the thickness direction of the backing metal.
Note that since no temporary welding or the like is required, attachment and detachment of the jig is extremely easy. FIG. 5 shows how to attach this jig to a long welding line, and the required number of the same jigs can be installed along the welding line. According to the experimental results, as welding progresses along the welding line, the heated part due to welding is thermally deformed and partially swells, and this bulge follows the progress of welding, like a wave moving on the water surface. After 2 to 3 hours have passed, the thermal deformation disappears due to cooling. During this time, each backing metal 1 freely expands and contracts with respect to the holding member 2 and undergoes angular displacement as shown in FIG. do. After removing the backing metal 1, the backing waves of the bead show uniform height and width,
It was extremely beautiful. The present invention is not limited to the above-mentioned embodiments, and various changes may be made without departing from the gist of the present invention, such as not necessarily using copper as the material of the backing metal. Of course. Since the backing metal jig for one-sided automatic welding of the present invention has the above-described configuration, it exhibits the following excellent effects. (i) Each backing metal is supported by an elastically deformable holding member through a backing metal mounting plate provided for each backing metal, and each backing metal mounting plate is held through a compressible member. Since it is supported by the member, it freely expands and contracts with respect to the holding member and undergoes angular displacement, and comes into close contact with the thermally deformed portion of the base material. (ii) The length of each backing is 3 to 6 of the major axis of the arc pool.
Since it is set to double, an appropriate gap can be formed between the base material and the backing metal when each backing metal is in close contact with the thermally deformed portion of the base metal. (iii) Through (i) and (ii) above, sufficient penetration is achieved, and regular back waves can be obtained, making it possible to obtain a highly reliable butt welded joint. 【table】

[Brief explanation of the drawing]

Fig. 1 is a plan view of a backing metal jig for one-sided automatic welding showing an embodiment of the present invention, Fig. 2 is a side view cut from the - direction in Fig. 1, and Fig. 3 is a - direction in Fig. 2. 4 and 5 are explanatory diagrams showing how to attach the backing metal jig for single-sided automatic welding to the base material in Figure 1, and Figure 6 shows the operation of the backing metal jig. It is an explanatory diagram. In the figure, 1 is a backing metal, 2 is a holding member, and 10 is a backing metal jig.

Claims (1)

[Scope of utility model registration request] A plurality of strip-shaped backing metals each having a length of 3 to 6 times the major axis of the arc pool, and a plurality of strip-shaped backing metals arranged at a distance from each other via a support member on the back side of the backing metals and set to approximately the same length as the backing metals. a backing metal mounting plate, an elongated holding member that supports the backing metal in a line in the longitudinal direction via the backing metal mounting plate, and the backing metal mounting plate and a holding member that faces the mounting plate. A single-sided automatic welding back comprising a compressible member disposed between the backing metal and the wall and pressing each backing metal to the front side of the backing metal via each backing metal mounting plate and the supporting member. Tokin jig.