JP3352501B2 - Steel welding method during rainfall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for welding steel frames during rainfall, and more particularly, to a method for connecting steel columns or new steel beams to existing steel columns by welding during rainfall.

[0002]

2. Description of the Related Art Conventionally, when a new steel column is connected to an existing steel column by welding, the connection has been performed as shown in FIGS. That is, at the upper end of the already-constructed steel column 1, two erection pieces 2 extending in the longitudinal direction are provided in parallel on each of a pair of opposing side surfaces. The erection piece 2 is previously welded to a steel column at a factory.

A backing metal 3 is previously attached to each inner surface of the upper end of the existing steel column 1 by welding, and these backing metal 3 project from the upper end surface of the existing steel column 1. It functions as a positioning member for a new steel column 4 described later. An erection piece 5 is attached to a pair of opposite side portions of the new steel column 4 connected to the already-installed steel column 1 in advance in the same manner as the end portion of the already-installed steel column 1 by welding. ing.

[0004] The new steel column 4 is constructed so that the above-mentioned backing metal 5 is fitted into the inside from the opening at the lower end.
And the end faces of both steel columns are positioned so as to secure a predetermined interval, that is, a groove 6. And the erection pieces 2, which are aligned on the longitudinal line,
Each of these pieces 2, so as to bridge to 5, and from both sides
The erection plate 7 is arranged so as to sandwich the rim 5, and is fastened with high tension bolts 8 to be temporarily assembled. Then, the end faces of the opposed steel columns 1, 4 facing each other at a predetermined interval 6 are welded over the entire circumference and according to a conventional method, so that the steel columns 1, 4 are firmly connected.

[0005]

However, in such a conventional connection method by welding steel frames, there is a problem that welding work cannot be performed during rainfall, and only when the weather is fine. In other words, on a rainy day, drips flow down the steel frame,
Moisture is mixed into the welding arc to create a blowhole, and the welding heat (arc is 4000-5000 ° C) transmitted in the longitudinal direction of the base material (existing steel column) during welding is rapidly cooled by water droplets. The quality of the welded portion is deteriorated because the material is deteriorated and becomes brittle as a result, and becomes a material having a built-in defect portion that is vulnerable to impact due to a decrease in metal elongation performance.

[0006] In addition, steel frame welding for forming a steel structure of a building is currently mostly electric welding. Therefore, when welding is performed in rainy weather, an electric shock accident may occur. Therefore, as a countermeasure for welding work in rainy weather, a method of hanging a roof using a sheet or the like so as to prevent rain from being applied to a welded portion has been adopted. However, when extremely long columns are connected by welding, it is very difficult to cover the top of the columns with a sheet, and therefore, usually a rain-proof sheet surrounds the periphery of the steel column to be welded. It was set up to surround it. For this reason, there was a risk that the drips would inevitably flow down to the steel column and fall on the weld.

[0007] Further, it is clear that such a roof is particularly effective in preventing the blowing of rain when the rain legs are relatively strong, but since the roof is relatively troublesome, it is difficult to prevent light rain. In such a case, it was desired to perform welding work under a simpler and more efficient rain-proof means without using such a large roofing. An object of the present invention is to solve such a conventional problem.When a new steel frame is connected to an existing steel column by welding at the time of rainfall, it flows down along the existing steel column and drips or scatters. An object of the present invention is to provide a steel frame welding method at the time of rainfall in which the deterioration of the quality of a welded portion due to the attachment of raindrops or the like is prevented by using rainproof means having a simple configuration.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for welding a steel frame during rainfall, and is constituted as follows to solve the above-mentioned technical problem. That is, in the present invention, a new steel frame 11 disposed so as to face the upper end of the already-constructed steel column 10 at a predetermined interval so that the ends thereof face each other is welded and connected to the already-constructed steel column 10 at the time of rainfall. In the method, the connecting flange portions formed substantially parallel to the end surfaces of the steel columns on the side surfaces near the opposite ends of the two steel columns are bolted to each other through a fastening fitting having a width larger than the width of the steel frames. When the two steel columns are temporarily assembled and welded between the opposed ends of the two steel columns, the vicinity of a portion to be welded between the already-constructed steel column 10 and the new steel frame 11 is preheated to remove moisture. And then wrapping the water-absorbing mat 18 around the existing steel column 10 or new steel frame 11 at least above the to-be-welded portion, and placing a plate on the shoulder protruding from the width of the steel frame of the fastener. Attached Rukoto, then it is welded to the welded portion to be in accordance with a conventional method, and is characterized by removing the water mat 18 after the natural cooling after welding weld.

[0009]

[0010]

[0011]

According to the method of welding a steel frame during rainfall according to the present invention, when a new steel frame (for example, a new steel column or steel beam) is connected to an already constructed steel column by welding during rainfall, a portion to be welded is preheated. To evaporate the water at the scheduled welding location.
Then, in order to prevent rainwater flowing down along the existing steel column, a water-absorbing mat is wound around the existing steel column or the new steel frame at least above the scheduled welding portion. Further, in order to prevent the attachment of rainwater or the like scattered from surrounding members or the like, such as other steel frames, a fastener fixed to the connecting flange, and a plate attached to the shoulder of the fastener, An eave is formed for a portion to be welded.

Next, the portion to be welded is welded according to a conventional method. After the welding is completed, the welded portion is left as it is for a certain period of time to cool naturally, and then the water-absorbing mat is removed. Accordingly, it is possible to prevent the welded portion from getting wet with rainwater until the welded portion reaches a predetermined quality state, and it is possible to obtain a good welded portion even during rainfall.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a method for welding steel frames during rainfall according to the present invention. 1 to 3 show a state in which a steel frame welding method at the time of rainfall according to an embodiment of the present invention is performed. The method of welding a steel frame during rainfall according to this embodiment is an example in which a new steel column is connected to an existing steel column by welding. That is,
This is a case where a new steel column 11 is connected by welding to the upper part of the hollow steel column 10 having a rectangular cross section that has already been constructed. In this case, on each inner side surface at the upper end of the already-constructed steel column 10,
As in the prior art, the backing metal 12 is attached in advance by welding, and the backing metal 12 protrudes from the upper end surface of the already-constructed steel column 10 and also functions as a positioning member for a new steel column 11 described later.

At the upper end of the already-constructed steel column 10, a pair of side portions near the ends is provided with a connecting flange portion 13 formed substantially in parallel with the end surface of the already-constructed steel column 10. The connecting flange 13 is welded to the steel column 10 at a factory in advance. In addition, this already-installed steel column 10
The connecting flange portion 14 is previously attached to a pair of opposite side portions of the new steel column 11 connected to the end portion of the new steel column 11 by welding just like the end portion of the already-constructed steel column 10.

The new steel column 11 is disposed directly above the already-constructed steel column 10 so that the above-mentioned protruding portion of the backing metal 12 is fitted into the inside from the opening at the lower end thereof. 11 are positioned so as to secure a predetermined interval, that is, a root gap 15. A square fastening ring 16 is arranged between the connecting flanges 13 and 14 arranged vertically in parallel from the side surfaces of the steel columns 10 and 11, and an upper side 16 a of the fastening ring 16 is connected to the lower surface of the connecting flange 14. And the lower side portion 16b is sandwiched so as to be in close contact with the upper surface of the connecting flange portion 13.

After that, the connecting flanges 13 and 14 and the lower side 16b and the upper side 16a of the fastening ring 16 are connected by bolts 17, whereby both steel columns 10 and 11 are connected.
Is tentatively assembled. As is apparent from FIG. 1, the fastening ring 16 is formed with a width dimension larger than the width of the steel column 10, and therefore, the left side 16 c and the right side 16 d of the fastening ring 16 are formed from the side portions of the steel columns 10 and 11. Located away.

Next, in this state, the two steel frames 10 and 11 are connected by welding. The portion to be welded is a gap between the opposite ends, that is, a root gap 15. Welding is performed. Before that, the periphery of the scheduled welding portion is preheated by a burner or the like, and the moisture adhering thereto is dried and removed.
After that, a water-absorbing mat 18 is wound around the already-constructed steel column 10 above and below the scheduled welding portion.

The details of the water absorbing mat 18 are shown in FIGS.
Is shown in The water-absorbing mat 18 has a cylindrical outer cover 18a made of a cloth having excellent water absorption such as cotton. A large number of magnets 19 are arranged on the inner surface of one side of the cylindrical outer cover 18a in a staggered manner in the longitudinal direction of the outer cover 18a when the cross-sectional shape is rectangular, and fixed to the outer cover 18a with a thread or the like. ing.

Further, the casing 18a is filled with a built-in material 18b made of a flexible material which is also excellent in water absorption, for example, cotton, cotton cloth or the like. Such a water-absorbing mat 18 is wound so that one side to which the magnet 19 is fixed is brought into close contact with the side surface of the steel column, whereby the water-absorbing mat 18 is self-fixed to the steel column by the magnetic force of the magnet 19.

This is possible because, when the two steel columns 10 and 11 are temporarily assembled, the fastening ring 16 as described above can be used as a configuration for fastening the two steel columns 10 and 11. . That is, since the fastening ring 16 as described above is arranged on the side of the steel column and formed with a width dimension larger than the width of the steel column, the water absorbing mat 1
This is because the steel frame 8 can make a round around the steel columns 10 and 11 without any obstacle.

Both ends of the water-absorbing mat 18 are abutted when wound around a steel column, and are firmly connected with a cloth tape (not shown) or the like so that no gap is formed therebetween.
Next, the opposing end faces are welded over the entire circumference and in a conventional manner, so that the two steel columns 10 and 11 are firmly connected. According to such a steel column welding method, when it rains,
The rainwater flowing down the new steel column 11 is absorbed by the water absorbing mat 18 and is prevented from flowing down to the welded portion.

The rainwater mat 18 arranged above the welded portion is sufficient for rainwater flowing down from above along the new steel column 11, but rainwater that has bounced off for some reason causes the steel frame on the lower side of the welded portion. Since the heat transmitted from the welded portion when attached to the column is rapidly cooled, it is preferable to wind the water-absorbing mat 18 also at this portion, that is, below the welded portion.

According to such an embodiment, both steel columns 1
Since the upper side 16a of the fastening ring 16 disposed on the pair of side surfaces 0 and 11 functions as an eave, the need for roofing with a sheet or the like is eliminated. However, the fastening ring 16
On the other pair of side portions of the steel column in which is not installed, the plate member 20 is fixed with bolts or the like so as to bridge over the shoulder portions of the two fastening rings 16 as shown in FIGS. To make an eaves.

[0024]

[0025]

[0026]

[0027]

[0028]

As described above, according to the method of welding a steel frame during rainfall according to the present invention, it is possible to prevent drips flowing down an already-constructed steel column and quality deterioration of a welded portion due to adhesion of scattered raindrops and the like. Since it is possible to perform welding work safely and without affecting the quality even in the case of a little rain, a very excellent effect such as shortening of the construction period is achieved.

[Brief description of the drawings]

FIG. 1 is a front view showing a state in which a new steel column is connected to an existing steel column by welding in a method of welding a reinforcing bar during rainfall according to one embodiment of the present invention.

FIG. 2 is a cross-sectional view partially showing a steel column connecting portion cut along a line 2-2 in FIG. 1;

FIG. 3 is a cross-sectional view partially showing a steel column connecting portion cut along line 3-3 in FIG. 2;

FIG. 4 is a partial sectional view showing a state in which a water-absorbing mat is wound around a steel column in the steel frame welding method during rainfall.

FIG. 5 is a partial cross-sectional view taken along line 5-5 of FIG. 4 and showing the configuration of the water-absorbing mat.

FIG. 6 is a partial cross-sectional view of a steel column connection portion showing a temporarily assembled state during conventional steel column welding connection.

FIG. 7 is a partial cross-sectional view of a conventional steel column connection section taken along line 10-10 in FIG. 6;

FIG. 8 is a side view of the conventional steel column connecting portion shown in FIG.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-209806 (JP, A) JP-A-51-128819 (JP, A) JP-A-56-99077 (JP, A) 143073 (JP, A) JP-A-3-161661 (JP, A) Japanese Utility Model Application Sho 55-1777979 (JP, U) Japanese Patent Publication No. 51-33646 (JP, B2) Japanese Patent Publication No. 49-44490 (JP, B1) (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/32 B23K 9/00 B23K 9/235 B23K 37/00 B23K 37/04

Claims (1)

(57) [Claims] Claims: 1. An existing steel column is mounted on the existing steel column.
Arranged so that the ends face each other at a predetermined interval
A method of welding and connecting the new steel frame at the time of rainfall , wherein the steel frame is provided on a side surface near the opposite end of the both steel columns.
Connecting flanges formed almost parallel to the end face of the column
Through a fastener having a width larger than the width of the steel frame.
And temporarily assemble the two steel columns,
When welding between the opposed ends , preheating around the portion to be welded between the already-constructed steel column and the new steel frame to evaporate moisture, and then the already-constructed steel column at least above the to-be-welded portion Alternatively, a water absorbing mat is wound around a new steel frame, and the steel
Steel plate welding during rainfall, comprising: attaching a plate material to a shoulder protruding from the width of the welding portion, then welding the to-be-welded portion according to a conventional method, and removing the water-absorbing mat after natural cooling of the welded portion after welding. Method.