JPH08239909A - Structure of joint for steel pipe, and joining method therefor - Google Patents

Abstract

PURPOSE: To reduce time and labor for processing at a factory for forming the structure for a joint end for a steel pipe while adopting a straight-cut shape that is available for easy processing at the factory and easy welding to be executed at a construction site, and to make work at the construction site easy while making the joint end available for being used in formation of closing members. CONSTITUTION: To the inside of steel pipes 11 and 12 for which joint ends are made in straight-cut shapes 13 and 14, end plates 15 and 16 are fixed beforehand at a factory so that the end plates can be approximately flush with the straight-cut shapes 13 and 14 on the joint ends. When erecting the steel pipes 11 and 12 at a construction site, an insert member 17 in a thickness corresponding to the distance between both of the joint ends is inserted between the end plate 15 and the end plate 16 and fixed by temporary welding. Then, welding is made along the insert member 17 and the joint ends, and thereby the steel pipes are joined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for welding steel pipes used for steel building and a joining method by welding.

[0002]

2. Description of the Related Art In the construction of steel-framed buildings, in recent years, steel pipes having a large diameter and an extremely thick cross section have been used very frequently as beams. Conventionally, as a joint structure and a joining method for on-site welding of a steel pipe (square pipe) having a large diameter and an extremely thick cross section as such a beam material, a “step cutting method”, a “backing plate sliding method”, There are "backing plate metal touch method" and "backing plate overhang method". Next, these conventional methods will be described with reference to the drawings.

(1) Step cutting method This step cutting method is a method generally used mainly for beam materials. First, as shown in FIG. 4A, steel pipes 41 to be joined to each other are used. , 42 are cut at the factory into step-shaped portions 43, 44, respectively, and the backing plate 4 is attached to the inner surfaces of the step-shaped portions 43, 44 at the factory.
5, 46 are respectively attached by welding. Then, as shown in FIG. 4 (B), the backing plates 45 and 46 are respectively provided to butt the step-cut portions 43 and 44, and welding is performed along the step-cut portions 43 and 44. ,
The steel pipes 41 and 42 are joined to each other.

(2) Backing Plate Sliding Method This backing plate sliding method is also a method generally used mainly for beam materials. First, as shown in FIG. The joints of the steel pipes 51, 52 to be
The direct cutting parts 53 and 54 are cut at the factory, and the backing plate 55 is attached to the steel pipe 51 in the factory by retracting it from the end of the joint (the direct cutting part 53). At least two pull-out handles 56 are attached to the outer surface of the backing plate 55 by welding so as to face each other in the diametrical direction. Further, the steel pipe 51 is provided with a throttle for allowing movement of the handle 56. A hole 57 is provided. The throttle hole 57 has, for example, a width of about 25 mm and a length of about 60 mm. Then, as shown in FIG. 5 (B), after the building on the site, the handle 56 is moved along the throttle hole 57 so that the backing plate 55 in the steel pipe 51 is connected to the connection end (the straight cut portion 53). ) And inserted into the other steel pipe 52, and the straight cut portions 53, 54
The steel pipes 51 and 52 are joined to each other by welding along the gap.

(3) Backing Plate Metal Touch Method This backing plate metal touch method is a method generally used mainly for pillar materials. First, as shown in FIG. 6 (A), The joint portions of the steel pipes 61 and 62 to be joined to each other are cut into direct cut portions 63 and 64 at the factory,
At the factory, the backing plate 65,
66 are attached. Here, one steel pipe 6
Approximately 7m from the back end plate (direct cut 63) to the backing plate 65 in 1
Welded in a state of protruding about m,
In the other steel pipe 62, a backing plate 66 is provided at a connection end (a straight cut portion 6).
Weld and attach in a state almost flush with 4).
Therefore, the backing plate 66 serves as a backing plate for the other backing plate 65. In order to secure a predetermined route gap at the time of construction at the site, the wood end faces of the backing plates 65 and 66 are subjected to accurate cutting and finishing. And FIG.
As shown in (B), the backing plate 6
Directly cut the parts 63 and 6
The steel pipes 61 and 62 are joined to each other by welding along the four spaces.

(4) Backing plate overhanging method This backing plate overhanging method is also a method generally used mainly for pillar materials. First, as shown in FIG. The joints of the steel pipes 71, 72 to be
The factory cuts the straight cut portions 73 and 74 respectively, and in the factory, the backing plate 75 is welded and attached to one of the steel pipes 71 in a state of projecting from the connection end (the straight cut portion 73). Then, as shown in FIG. 7 (B), at the time of construction at the site, the backing plate 71 of the steel pipe 71 is inserted into the other steel pipe 72, and then welded along the straight cut portions 73, 74. Then, the steel pipes 71 and 72 are joined to each other.

[0007]

However, any one of the above-described conventional "step cutting method", "backing plate sliding method", "backing plate metal touch method", and "backing plate overhanging method" is used. Also, there is a problem in manufacturing or on-site construction as described below.

(1) Step Cutting Method In the case of the step cutting method, first, steel pipes 41 and 4 are produced at a factory.
The work of cutting the second connection into the step-shaped portions 43 and 44 is required, and such step-cutting is a complicated and time-consuming operation. Further, the mounting accuracy of the backing plates 45, 46 to the inner surfaces of the stepped portions 43, 44 is required, and the stepped portions 43, 4 provided with such backing plates 45, 46, respectively.
It is difficult to make a joint when the steel pipes 41 and 42 are to be built by the method of No. 4. Further, the welding length along the step-shaped portions 43 and 44 at the site is long and complicated, and welding defects are easily generated at the corners of the step-shaped portions 43 and 44, so that skill in welding can be improved. It costs.

(2) Backing Plate Sliding Method In the case of the backing plate sliding method, first, the backing plate 55
At least two handles 56 for pulling out are attached to the steel pipe 5 and a throttle hole 57 for allowing the movement of the handles 56.
In the case where the steel pipe 51 is an extremely thick member, there are many cross-sectional defects and the backing plate 5 is inserted into the steel pipe 51.
It takes time to attach the handle 5 and the handle 56 to the backing plate 55. Further, it is necessary to cut the handle 56 after the completion of welding on site and fill the throttle hole 57.

(3) Backing plate metal touch system In the case of the backing plate metal touch system, first, the steel pipe 6
Since the backing plate 65 projects from the end (direct cut portion 63) of No. 1, when building as a closing member, since there is no clearance, it is difficult to build. Also, steel pipe 6
Manufacturing errors and on-site construction errors are often accumulated at the joints of Nos. 1 and 62, and it is very difficult to adjust the error due to the route gap.

(4) Backing plate overhanging method In the case of the backing plate overhanging method, it is relatively easy to attach the backing plate 75 to the steel pipe 71 at the factory, but the connection end of the steel pipe 71 ( Since the backing plate 75 projects from the straight cut portion 73), it cannot be built as a closing member.

[0012] Therefore, an object of the present invention is to form a connection by direct cutting, which is easy to process at a factory and weld at the site, thereby reducing processing time at the factory and facilitating construction at the site. Another object of the present invention is to provide a steel pipe joint structure that can be constructed and used as a closing member. Another object of the present invention is to provide a method for joining steel pipes with the above-described joint structure.

[0013]

In order to solve the above-mentioned problems, the invention according to claim 1 is a joint portion structure of steel pipes in which each joint end is a straight cut portion, and in the inner portion of the steel pipe, A configuration including an end plate fixed substantially flush with the straight cut portion of the joint end, and an intermediate member inserted between the joint ends of the steel pipe and fixed to the end plate, respectively. Is characterized by.

According to a second aspect of the present invention, in the steel pipe joint structure according to the first aspect, the interposed member is constituted by a plurality of divided bodies in a circumferential direction. And

According to a third aspect of the present invention, in the method for joining steel pipes in which the ends of the joints are straight cut parts, the inner surface of the steel pipe is substantially flush with the straight cut parts of the joint ends in advance. After fixing the end plates respectively, and inserting and fixing the interposed member corresponding to the gap between the ends of the connection when the steel pipe is erected, the interposed member and the connection The invention is characterized in that the steel pipes are joined to each other by welding along the ends.

According to a fourth aspect of the present invention, in the method for joining steel pipes according to the third aspect, after measuring the interval between the ends of the connection, a plurality of the intervening members corresponding to the interval are formed in the circumferential direction. It is characterized in that the divided body divided into is inserted between the end plates and fixed by temporary attachment welding.

[0017]

According to the first aspect of the present invention, the inner surface of the steel pipe is
Since the end plates are fixed so that they are flush with the straight cut portion of the joint end, and further, an interposing member is inserted between the joint ends of the steel pipes and fixed to the end plates respectively. First of all, since the shape of the connection is made by direct cutting, it is easy to process in a factory and easily perform welding in the field. In a factory, since the end plate may be fixed to the inner surface of the steel pipe so as to be substantially flush with the cut portion at the end of the connection end, the end plate can be easily attached. At the site, since the structure is such that the interposed members are fixed to the end plates on the inner surface of the steel pipe and the interposed members are interposed between the ends of the connection, construction at the site can be easily performed, and furthermore, due to the existence of the route gap, the connection is made. It can be built as a member.

According to the second aspect of the present invention, since the intermediate member is constituted by a plurality of divided bodies in the circumferential direction, the intermediate member is provided between the end plates at the connection end of the steel pipe. Insertion is facilitated by inserting the segments individually.

According to the third aspect of the invention, the end plates are fixed to the inner surface of the steel pipe in advance so as to be substantially flush with the straight cut portion of the joint end, and the end plate is fixed when the steel pipe is built. This is a joining method of joining steel pipes to each other by inserting and fixing an interposing member corresponding to the gap between the mouth ends between the end plates, and then welding the interposing members and the joint ends together. Since it has a cut shape, it can be easily processed in the factory and can be easily welded on site. In a factory, since the end plate may be fixed to the inner surface of the steel pipe so as to be substantially flush with the cut portion at the end of the connection end, the end plate can be easily attached. Furthermore, when building steel pipes on site,
Inserting an interposing member corresponding to the gap between the joint ends between the end plates on the inner surface of the steel pipe and interposing between the joint ends, and fixing the interposing members to the end plates respectively, construction at the site It is also easy to perform, and due to the existence of the root gap, it can be built as a closing member.

According to the fourth aspect of the present invention, after measuring the gap between the ends of the steel pipe, the divided body divided into a plurality in the circumferential direction constituting the interposed member corresponding to the gap is provided on the end plate. First, the interposed member corresponding to the gap between the ends of the steel pipe can be reliably inserted, and the interposed member can be inserted between the end plates. , Can be easily performed by individually inserting the divided bodies.

[0021]

Embodiments of the joint structure and joining method for steel pipes according to the present invention will be described below with reference to FIGS. 1 to 3. First, FIG. 1 shows a joint structure and a joining method for in-situ welding of steel pipes as an example to which the present invention is applied. (A) is a mutual joint of steel pipes with a backing plate attached. FIG. 3B is a side view showing the joined state of the steel pipe joints. In FIG. 1, 11 and 12 are steel pipes, 13 and 14 are connection ends (direct cut portions), 15 and 16 are end plates, and 17 is an interposed member (steel backing).
Is.

That is, in this embodiment, first, FIG.
As shown in (1), the joint portions of the steel pipes 11 and 12 to be joined to each other are cut into straight cut portions 13 and 14 at a factory, and end plates 15 and 16 are inserted into both the steel pipes 11 and 12 at the factory. Install each one. here,
The end plates 15 and 16 are welded and attached in the two steel pipes 11 and 12 in a state that they are substantially flush with the ends of the joints (direct cut portions 13 and 14). Then, FIG. 1 (B)
As shown in the figure, the steel pipe 11,
A space is provided at the end of the connection (straight cut portions 13, 14) of 12, and a steel backing 17 as an interposed member is inserted between end plates 15, 16 fixed to the inner surfaces thereof, and temporarily welded. The main welding is performed between the steel backing 17 and the straight cut portions 13 and 14 (weld portion 18 in FIG. 2).
), The steel pipes 11 and 12 are joined to each other.

FIG. 2 is an enlarged view showing the structure of the joint portion of the steel pipe joint shown in FIG. 1 (B). In the embodiment, a large-diameter pipe having an outer diameter of 511.6 mm and a wall thickness of 30 mm is shown. The steel pipes 11 and 12 having an extremely thick cross section are used, and the groove angle is 40 ° and the root gap is 12 mm. Also,
A cylindrical end plate 1 with a wall thickness of 12 mm
5 and 16, and have an outer diameter of 4
A steel backing 17 with a width of 78.6 mm and a thickness of 10 mm is used. As the ring-backed steel backing 17, as shown in FIG. 3 (A), divided bodies 17a and 17a which are divided into two equal parts are used, or as shown in FIG. Divided body 17 divided into equal parts
b, 17b, 17b, 17b are used.

Next, a specific joining method at the site will be described. As shown in FIG. 2, the above-mentioned outer diameter 511.6
Steel pipes 11 and 12 each having a large diameter and an extremely thick cross section made of a round pipe having a wall thickness of 30 mm and a thickness of 30 mm are positioned with their ends facing each other with an interval therebetween, and the ends of the ends (the straight cut portion 1)
Measure the interval between 3, 14). In the embodiment, the interval between the connection ends is the above-described root gap 12 mm. Then, a ring-shaped steel backing 17 having a width (plate thickness) of 10 mm and an outer diameter of 478.6 mm corresponding to the root gap of 12 mm is inserted between the connection ends of the steel pipes 11 and 12, and the steel pipe is inserted. A steel backing 17 is fixed to each of the end plates 15 and 16 which are welded to the end plates 11 and 12 so as to be substantially flush with the connection ends (the straight cut portions 13 and 14), respectively, by tack welding.

That is, the divided body 17a, 17a divided into two as shown in FIG. 3A or the divided body 17b, 17b, 17b, 17b divided into four as shown in FIG. 3B.
Are successively inserted between the joint ends (the straight cut portions 13 and 14) of the steel pipes 11 and 12, and the end plates 15 and 1
6 is fixed one after another by tack welding. Thereafter, a steel plate backing 17 having such a width (plate thickness) of 10 mm is interposed, and a root gap of 12 mm and a groove angle of 40 ° are used to connect the ends of the steel pipes 11 and 12 (direct cut portion 1).
By carrying out the main welding along the interval (3, 14), a welded portion 18 as shown is obtained, and the steel pipes 11 and 12 are firmly joined to each other.

Therefore, according to the connection structure and the joining method of the steel pipe according to the present invention as described above, even when the closing member is to be built, the welding is performed by performing the reliable welding using the root gap. Can be In addition, steel pipe 11,
The error accumulated between the 12 connection ends (the straight cut portions 13 and 14) can be adjusted by the root gap.
And, in the factory, the joint ends of the steel pipes 11 and 12 are
It is only necessary to cut each of the straight cut portions 13 and 14 and weld the inner surfaces of the end plates 15 and 16 for temporary attachment of the steel backing 17 to be substantially flush with the straight cut portions 13 and 14, respectively. Therefore, processing time in a factory can be reduced.

At the site, after actually measuring the distance between the connection ends (straight cut portions 13, 14) of the steel pipes 11, 12, the divided body of the steel backing 17 corresponding to the root gap is inserted and the end plate is inserted. After the tack welding is performed at 15 and 16, the main welding is performed between the ends of the joints (direct cut portions 13 and 14), so that the on-site construction can be easily performed. As described above, the present invention provides a steel backing 1
7 can be called a steel backing method because it is a connection of a steel pipe to a joint portion.

In the above embodiment, the joint of the steel pipe is used. However, the present invention is not limited to this, and may be applied to the joint of a box-shaped portion.
In addition, the interposed member (steel backing) may be further subdivided into three or five or more, and it goes without saying that the specific detailed structure and the like can be appropriately changed.

[0029]

As described above, according to the joint structure for a steel pipe according to the first aspect of the present invention, the end plate is formed on the inner surface of the steel pipe so as to be substantially flush with the straight cut portion at the end of the joint. The structure is fixed to each, and furthermore, an interposed member is inserted between the ends of the steel pipe to be fixed to the end plates, respectively. Can be easily performed together.
Further, in the factory, the end plate may be fixed to the inner surface of the steel pipe so as to be substantially flush with the straight cut portion at the end of the connection, so that the end plate can be easily attached, and therefore, Processing time can be reduced. And at the site, because the structure is fixed to the end plate on the inner surface of the steel pipe and the interposing member is interposed between the end portions of the steel pipe, the construction at the site can be easily performed, and the existence of the root gap It can also be built as a closing member.

Further, according to the steel pipe joint structure according to the second aspect of the present invention, since the interposed member is constituted by a plurality of divided bodies circumferentially divided, the end plate at the joint end of the steel pipe. Insertion of the interposed member into the space can be easily performed by individually inserting the divided bodies.

According to the method of joining steel pipes according to the third aspect of the invention, the end plates are fixed to the inner surface of the steel pipe in advance so as to be substantially flush with the straight cut portion at the end of the connection. A method of joining steel pipes to each other by inserting and fixing an interposed member corresponding to the gap between the ends of the joints when building the steel pipes between the end plates, and then welding along the interposed members and the ends of the joints. First of all, since the shape of the connection is made by direct cutting, it is possible to easily perform both the processing in the factory and the welding in the field. In the factory,
Since it suffices to fix the end plate to the inner surface of the steel pipe so that it is approximately flush with the straight cut part of the end of the steel pipe, the end plate mounting work can be performed easily, thus reducing the processing labor in the factory. can do. Furthermore, when building the steel pipe at the site, an interposed member corresponding to the interval between the ends of the steel pipe is inserted between the end plates on the inner surface of the steel pipe, interposed between the ends of the steel pipe, and the interposed member is inserted. Because of the method of fixing to each end plate, construction on site can be easily performed, and further, as a closing member, it can be built as a closing member due to the existence of the root gap.

According to the steel pipe joining method of the fourth aspect of the present invention, after the distance between the joint ends of the steel pipe is measured, the steel pipe is divided into a plurality of pieces in the circumferential direction constituting the interposing member corresponding to the distance. Since the divided body is inserted between the end plates and fixed by temporary welding, first, it is possible to surely insert the interposing member corresponding to the interval between the joint ends of the steel pipe, and moreover,
The interposition member can be easily inserted between the end plates by individually inserting the divided bodies.

[Brief description of drawings]

FIG. 1 shows a joint structure and a joining method for in-situ welding of a steel pipe as an example to which the present invention is applied,
(A) is a side view which shows the steel pipe connection part of the state which attached the backing plate, (B) is a side view which shows the joining state of the steel pipe connection part.

FIG. 2 is a vertical cross-sectional side view of essential parts showing an enlarged structure of a joint portion of the steel pipe joint portion shown in FIG. 1 (B).

FIG. 3 shows an example of a divided shape of a steel backing material used in the present invention, (A) is a front view in the case of two divisions,
(B) is a front view in the case of four divisions.

FIG. 4 is a view showing a joint structure and a joining method for in-situ welding of a steel pipe by a conventional “step cutting method”.
FIG. 3 is a side view showing the steel pipe joints with the backing plate attached, and FIG. 2B is a side view showing the joined state of the steel pipe joints.

FIG. 5 shows a joint structure and a joining method for in-situ welding of steel pipes according to a conventional “backing plate slide system”, and (A) shows one another with a backing plate attached to only one side. FIG. 3B is a side view showing the steel pipe joint portion, and FIG. 6B is a side view showing the joined state of the steel pipe joint portions.

6A and 6B show a joint structure and a joining method for on-site welding of steel pipes by a conventional “backing plate metal touch method”, in which FIG. 6A shows a steel pipe joint with a backing plate attached. FIG. 4B is a side view showing a mouth, and FIG. 4B is a side view showing a joined state of the steel pipe joints.

7A and 7B show a joint structure and a joining method for on-site welding of a steel pipe by a conventional “backing plate overhanging method”. FIG. 7A shows each other with a backing plate attached to only one of them. FIG. 3B is a side view showing the steel pipe joint portion, and FIG. 6B is a side view showing the joined state of the steel pipe joint portions.

[Explanation of symbols]

 11, 12 Steel pipe 13, 14 Port end (direct cut portion) 15, 16 End plate 17 Interposing member (steel backing) 17a, 17b Divided body 18 Welded portion

Claims (4)

[Claims] An end plate fixed to an inner surface of said steel pipe so as to be substantially flush with said straight cut portion of said connection end, wherein said end plate is fixed to an inner surface of said steel pipe. And an intervening member inserted between the ends of the steel pipe and fixed to the end plate, respectively. 2. The joint structure for a steel pipe according to claim 1, wherein said interposed member is constituted by a plurality of divided bodies divided in a circumferential direction. 3. A method for joining steel pipes wherein the ends of the joints are straight cut parts, wherein end plates are respectively fixed to the inner surface of the steel pipe in advance so as to be substantially flush with the straight cut parts of the joint ends. After inserting an interposed member corresponding to the interval between the ends of the connection when the steel pipe is erected and fixing the interposed member between the end plates, welding along the interposed member and the end of the connection. A method for joining steel pipes, wherein the steel pipes are joined to each other by the following method. 4. After the measurement of the distance between the joint ends, a plurality of divided bodies in the circumferential direction that compose the interposing member corresponding to the distance are inserted between the end plates and temporarily welded. The steel pipe joining method according to claim 3, wherein the steel pipes are fixed.