JP2001355286A - Rectangular steel pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem of jointing in nonconformity in shape caused by the difference of angular part shape based on wall thickness of rectangular steel pipes serving as column members in the same column section with the same side length, and permit the product integration of the rectangular steel pipes in the approximate size range of side length and the interchangeability of the rectangular steel pipes formed in different methods. SOLUTION: The shape of angular parts of a plurality of rectangular steel pipes different in wall thickness T in the same column section with the equal length L of outline sides is made the same, or the rectangular steel pipes are grouped in a plurality of units according to the wall thickness, and the shape of the angular parts are unified group by group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a square steel pipe, and more particularly to a square steel pipe suitable for use in building structures such as pipe columns.

[0002]

2. Description of the Related Art In general, square steel pipes are frequently used as pillars for steel structures of buildings. The manufacture of this square steel pipe
A so-called roll column in which an ERW pipe is cold or hot formed by a roll, a so-called press column in which a steel plate is press-formed in a U-shape and welded, a so-called seamless column in which a seamless steel pipe is hot-formed, and the like are known. . At present, most of them are roll columns and press columns.
Standards for square steel pipes for general structures (JIS G 3466) or cold-formed square steel pipes for building structures (BCR / BCP) (Steel Club). Stipulated.

[0003] An example of a typical roll column standard,
Table 1 shows the side length L, wall thickness T, and radius of curvature (corner R) of the corners of the square steel pipe size.

[0004]

[Table 1]

That is, the length L (side length) of one side of the outer shape is 3
In the case of a square steel pipe having a square shape of 00 mm, the wall thickness T is 6.
Six types of thicknesses are defined from 0 to 19.0 mm. The standard values of the radius of curvature (corner R) of the corners of the six types of rectangular steel pipes in the same column section having the same side length L and different wall thicknesses T are 2. 5
× T (dimension tolerance ± 0.5). Also,
In the case of the press column of 300 mm, the wall thickness is 9.
Five types are limited from 0 to 19 mm, and the standard value of the radius of curvature of the corner is 3.5 × for each thickness T.
T is defined. That is, even in the case of rectangular steel pipes in the column section having the same size, different corners R are provided for respective wall thicknesses. This is because, in the forming process of the roll column and the press column, since the bending limit of forming the corner portion by forming is determined by the thickness of the material, different corners R are determined depending on the thickness. .

However, when these rectangular steel pipes are used as pillars (columns) for building structures, for example, T1 and T2 rectangular steel pipes having different wall thicknesses within the same column section (having the same outer side length). Causes the following problem with the corners R being R1 and R2, respectively.

(1) When joining a rectangular steel pipe having a thin upper column and a rectangular steel pipe having a lower thickness in the longitudinal direction, FIGS. 1 (a), (b) and (c) are shown. as such, the corner portion 3 of one side 2 match the outer shape portion 1 of the square steel tube, as on pillars 5 thin indicated by the solid line of the corner R ₁ under column 4 thick indicated by the broken line of the corner R ₂ The corners have different shapes depending on the wall thickness. For this reason, in joining, as shown in FIG. 1 (b), a step 6 is formed at a corner portion, so that it is difficult to perform the work, and the scenery after joining is not good. In addition, FIG.
FIG. 1A is a cross-sectional view taken along line AA of FIG.
It is a BB sectional view of (a).

(2) As shown in FIG. 2, when the beam 8 is joined from the column member 7 of the rectangular steel pipe, the fact that the corner R is different means that the length (ΔL) 9 of the non-linear portion is different. That is, the dimension of the beam 8 differs from the outside 10 or the inside 11 of the column material. Therefore, the length of the straight portion connecting the beams 8 changes depending on the wall thickness, and it is also difficult to perform the construction.

(3) Further, as shown in FIG. 3, when the beam 8 is joined from the column member 7 of the square steel pipe in a cross shape using a diaphragm, the outer shape of the square steel pipe does not match due to the wall thickness. Since the same diaphragm 12 cannot be used and a gap 30 is formed in the corner portion 3, the welding amount is adjusted. This affects the construction period and construction costs.

[0010]

SUMMARY OF THE INVENTION Therefore, the present invention
Square steel pipes in the same column section with the same side length, due to different corner shapes due to wall thickness,
It is a first object of the present invention to solve the above-mentioned joining problem as a pillar material.

A second object of the present invention is to consolidate products and provide interchangeability of square steel pipes having different forming methods for square steel pipes whose side lengths are in a range of approximate sizes.

[0012]

SUMMARY OF THE INVENTION To summarize the features of the rectangular steel pipe of the present invention, if the sides have the same length, that is, if they have the same size, their outer shapes must be the same even if they have different wall thicknesses. Thus, the above problem has been solved. Specifically, the fact that the outer shapes are the same means that the shapes of the corners are the same, and consequently that the lengths of the straight portions of the sides are equal.

The gist of the present invention is as follows.

(1) A plurality of (S) rectangular steel pipes having different wall thicknesses (T) in the same column section having the same outer side length (L) have the same corner shape. Square steel pipe.

(2) A plurality (S) of square steel pipes having different wall thicknesses (T) in the same column section having the same outer side length (L) are grouped into a plurality of units according to the wall thickness. A square steel pipe characterized in that the shape of the corners is unified for each group.

(3) The rectangular steel pipe according to (2), wherein the shapes of the corners of the rectangular steel pipe are integrated into two or three groups according to the wall thickness.

(4) The square steel pipe according to the above (1) or (2), wherein the corners have a curved shape, and the curved portions (R) of the corners have the same shape. .

(5) The square steel pipe according to the above (1) or (2), wherein the shape of the corner portion is straight, and the straight portion (C) of the corner portion has the same shape. .

(6) The side length (L), wall thickness (T) and shape of the corners are all of a square steel pipe standard for general structure (JIS).
G 3466), within the dimensional tolerance set forth in any of (1) to (5).

(7) The rectangular steel pipe according to any one of the above (1) to (6), which is processed by hot rolling.

(8) The rectangular steel pipe according to the above (7), which is a seamless steel pipe processed by hot rolling.

(9) The square steel pipe according to the above (8), which is a seamless steel pipe formed by a hot rolled two-roll, three-roll or four-roll molding machine.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the embodiments shown in the drawings.

FIG. 4 is a view showing an example of a square steel pipe having a corner portion (corner portion) 3 having a constant curvature R (corner R).
Note that the corner portion (corner portion) will be described as an example in the case of a curved line. However, as shown in FIG. 5, the corner portion (corner portion) is a straight corner portion 16 (corner C) whose corner is dropped. Even
The same effect is exhibited, and the present invention also includes this type of square steel pipe.

In FIG. 4, reference numeral 1 denotes an outer shape of a rectangular steel pipe, 3 denotes a corner (curvature R), 13 denotes a length (L) of a side, and 14 denotes a straight part of the side.

In the present invention, the square steel pipe having an outer shape with a side length of 13 is defined as "the same column section".
Multiple (S) thicknesses T ₁ , T ₂ ... T within the same column section
_The square steel pipe having _n is classified. These are illustrated only two inner shape 15 _1, 15 ₂ are omitted in the drawings.
Regardless of the thickness of the rectangular steel pipe, the corner portion has the same curvature R, and therefore, the length 14 of the straight portion having the side length 13 is also the same. That is, it has the outer shape 1 of the common square steel pipe.

[0027] These actual dimensions, for example, the tolerances specified in the standards for cold-formed square steel pipes (BCR, BCP) for building structures are acceptable and are naturally included in the present invention. That is, the length of the side is ± 1.0% and ± 3.0 mm, and the corner (curvature)
R ± 0.5T (T = wall thickness).

The determination of the corner R may be basically any curvature specified in the standard by the wall thickness. For example, in a roll column having a side length of 250 mm in Table 1, the corner R of a 6.0 mm square steel pipe having a minimum thickness of 15 mm is 15 mm.
You may apply all to the thing of 0 mm.

Further, a corner R 22.5 mm having a thickness of 9.0 mm, which is an intermediate size, can be applied unified to the entire thickness, and a corner R 40 mm having a maximum thickness of 16.0 mm can be selected. May be. Table 2 shows an embodiment in which the corners of the intermediate size are unified to 22.5 mm or 30 mm.

[0030]

[Table 2]

Further, in determining the corner R, it is effective to consider various manufacturing methods described in the description of the conventional method.

That is, in the case of the roll column method, 25
In the case of 0 mm square (square), the corner R is set to 40 mm with a maximum thickness of 16 mm that can be manufactured.
It is unified to a corner radius of 9.0 mm and 48 mm. This example is shown in Tables 3 and 4.

[0033]

[Table 3]

[0034]

[Table 4]

In the case of the seamless column method,
Since the hot rolling method using a grooved roll (well-known), the corner R can be reduced depending on the shape of the grooved shape. Therefore, 250m
In the case of m-square, the corner R can be unified to 15 mm, and in the case of 300 mm, the corner can be unified to 15 mm.

Further, for example, in the case of a 250 mm square, a corner R4 having a maximum thickness of 16 mm which can be manufactured by the roll column method.
In the case of 0 mm and 300 mm square, the compatibility with the roll column method is also effective by setting the corner R to 48 mm with a maximum thickness of 19 mm that can be manufactured by the roll column method.

The above description is an example in which various thicknesses in the same column section having the same side length are unified to one corner R, but the adjacent thickness levels (ranges) in the same column section. Can be aggregated into several groups, and a single corner R can be determined in each group.

For example, as shown in Table 5, type 1 of thickness
In the case of 750 mm square with 0 types, 12 ≦ T
≤22, 22 <T≤40, suitable corner R55mm or 100mm in that range
Unify to.

[0039]

[Table 5]

Of course, it may be divided into three groups depending on the wall thickness. However, if the number of groups is increased too much, square steel pipes having different outer shapes will be held in the same column section, and the intended purpose of the present invention will be described. The effect is diminished, so at most 3
If the grouping is performed, two groups are practical.

Next, examples of manufacturing these square steel pipes are shown in FIGS.
This will be described with reference to FIG.

In the roll column method, as shown in FIG. 6, a welded steel pipe 18 is formed from a coil 17 and roll-formed cold or hot to form a square steel pipe 19 having a corner R. The method of roll forming a roll 20 _1, as shown in FIG. 9 (a)
And 20 ₂ of the second roll, 3 roll of the roll 21 ₁ to 21 ₃ as shown in FIG. (B), the roll 22 ₁ to FIG. (C)
22 There are _four of the four-roll method. In the case of cold roll forming, the corner R of 2.5 times the sheet thickness is the limit, and in order to manufacture the rectangular steel pipe of the present invention, it is necessary to match the thickness with the thicker manufacturable wall thickness (ie, And the corner R becomes larger).

In the press column method, as shown in FIG. 7, a steel plate 23 is pressed into a groove to form a grooved steel 24.
Square steel pipe 2 having corner R by welding and assembling
5 is manufactured. Even in the case of cold press forming, 3.
The corner radius R of 5 times is the limit, and in order to manufacture the square steel pipe of the present invention, it is necessary to adjust the thickness to the thicker that can be manufactured. (That is, the corner R increases.)

In the seamless column method, as shown in FIG. 8, a seamless steel pipe 28 is formed from a square bloom 26 or a round billet 27 by roll rolling or hot pressing, and hot roll-formed to form a square steel pipe having a corner R. 29 is manufactured. The method of roll forming, as shown in FIG. 9 (a) rolls 20 ₁ and 20 ₂ of the second roll as shown in FIG 3 of the roll 21 ₁ to 21 ₃ as shown in FIG. (B) roll, in FIG (c) Roll 2
There are four roll type 2 _{1-22 4.} The seamless column method is easier than the former two methods since the forming of the corner is hot, and has a feature that the square steel pipe of the present invention can be manufactured with a small corner R.

As described above, the square steel pipe of the present invention shown in FIGS. 4 and 5 and Tables 2 to 5 is obtained.

[0046]

According to the rectangular steel pipe of the present invention, the following remarkable effects can be obtained.

(1) When joining a rectangular steel pipe in the longitudinal direction,
In the corner portion corresponding to the cross section AA in FIG. 1 at the outer side, the "step" does not occur, as in the cross section BB in FIG. 1C. Therefore, if the square steel pipe of the present invention is used, the construction is easy and the landscape after joining is good.

(2) When joining a beam from a columnar steel pipe, the fact that the corner R is the same means that the length of the non-linear portion is ΔL.
Therefore, the lengths of the straight portions joining the beams are unified, and the construction is easy (see FIG. 2).

(3) When joining a beam from a square steel pipe column using a diaphragm, the outer shape is constant.
Since there is no gap at the corner R, the same diaphragm can be used, which is advantageous in terms of construction period and construction cost (see FIG. 3).

(4) Even with columns having the same side length, the manufacturing method,
By unifying the corner (corner) shape that was different depending on the wall thickness, it is possible to replace a thin-walled square steel pipe with a thick-walled square steel pipe regardless of the manufacturing method as long as the material is the same. There is an advantage that emergency response and inventory reduction are possible.

[Brief description of the drawings]

FIG. 1 is a view for explaining that a step is generated at a corner portion when joining square steel pipe columns having different wall thicknesses;
(B) is an AA cross-sectional view of (a), and (c) is B of (a).
It is -B sectional drawing.

FIG. 2 is a view showing that a beam is joined from a square steel pipe column material.

FIG. 3 is a view showing that a beam is joined to a square steel pipe column using a diaphragm.

FIG. 4 is a view showing a square steel pipe having a corner portion having a constant curvature (corner) R;

FIG. 5 is a view showing a square steel pipe having a straight corner part whose corner part (corner part) is cut off.

FIG. 6 is a diagram showing an example of manufacturing a square steel pipe by a roll column method.

FIG. 7 is a view showing an example of manufacturing a square steel pipe by a press column method.

FIG. 8 is a diagram showing an example of manufacturing a square steel pipe by a seamless column method.

FIG. 9 is a diagram schematically showing a two-roll system, a three-roll system, and a four-roll system by a roll forming method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 External part of square steel pipe 2 Side 3 Corner part 4 Thick lower pillar 5 Thin upper pillar 6 Step 7 Column material 8 Beam 9 Non-linear length (ΔL) 10 Outside 11 Inside 12 Diaphragm 13 Side length ( L) 14 side straight portion 15 ₁ of 15 _second inner form 16 linear corner portion 17 coil 18 welded pipes 19 roll forming the square steel pipes 20 _1, 20 ₂ roll 21 _1, 21 _2, 21 ₃ roll 22 _1, 22 ₂ , 22 ₃ , 22 ₄ roll 23 steel plate 24 channel steel 25 welded and assembled square steel tube 26 square bloom 27 round billet 28 seamless steel tube 29 roll-formed square steel tube 30 gap

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsutomu Kawahara 1-1 Niwahata-cho, Tobata-ku, Kitakyushu Nippon Steel Corporation Yawata Works (72) Inventor Yumi Shimura 2-6 Otemachi, Chiyoda-ku, Tokyo -3 Inside Nippon Steel Corporation (72) Inventor Masao Sonoda 4-10-1 Chiharadai, Ichihara-shi, Chiba 3-6 Shiki-no-oka 3-6 F-term (reference) 2E163 FA02 FB07 FB09

Claims (9)

[Claims] 1. A plurality of (S) rectangular steel pipes having different wall thicknesses (T) in the same column section having the same side length (L) of the outer shape have the same corner shape. Square steel pipe. 2. A plurality of (S) square steel pipes having different wall thicknesses (T) in the same column section having the same outer side length (L) are grouped into a plurality of units according to the wall thickness, A square steel pipe characterized by having a uniform corner shape for each group. 3. The rectangular steel pipe according to claim 2, wherein the shapes of the corners of the rectangular steel pipe are integrated into two or three groups according to the wall thickness. 4. The square steel pipe according to claim 1, wherein the corners have a curved shape, and the curved portions (R) of the corners have the same shape. 5. The square steel pipe according to claim 1, wherein the shape of the corner portion is straight, and the straight portion (C) of the corner portion has the same shape. 6. The side length (L), the wall thickness (T) and the shape of the corners are all of a square steel pipe standard for general structure (JIS G).
The rectangular steel pipe according to any one of claims 1 to 5, wherein the dimensional tolerance is within a dimensional tolerance defined in 3466). 7. The rectangular steel pipe according to claim 1, wherein the steel pipe is processed by hot rolling. 8. The rectangular steel pipe according to claim 7, which is a seamless steel pipe processed by hot rolling. 9. The rectangular steel pipe according to claim 8, wherein the steel pipe is a seamless steel pipe formed by a two-roll, three-roll, or four-roll mold machine for hot rolling.