JPH11169947A - Production of square steel tube - Google Patents

Production of square steel tube

Info

Publication number
JPH11169947A
JPH11169947A JP34045297A JP34045297A JPH11169947A JP H11169947 A JPH11169947 A JP H11169947A JP 34045297 A JP34045297 A JP 34045297A JP 34045297 A JP34045297 A JP 34045297A JP H11169947 A JPH11169947 A JP H11169947A
Authority
JP
Japan
Prior art keywords
square steel
steel pipe
steel tube
forming
shape
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP34045297A
Other languages
Japanese (ja)
Other versions
JP3292829B2 (en
Inventor
Hiroshi Nakajima
拓 中島
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nakajima Steel Pipe Co Ltd
Original Assignee
Nakajima Steel Pipe Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nakajima Steel Pipe Co Ltd filed Critical Nakajima Steel Pipe Co Ltd
Priority to JP34045297A priority Critical patent/JP3292829B2/en
Publication of JPH11169947A publication Critical patent/JPH11169947A/en
Application granted granted Critical
Publication of JP3292829B2 publication Critical patent/JP3292829B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Abstract

PROBLEM TO BE SOLVED: To provide a producing method of a square steel tube, by which quality improvement of a square steel tube in hot forming is secured, loss due to forming is reduced, a recessed part is hardly generated at a flat part (four side plate parts) and a shape of each corner part is made equal. SOLUTION: A semi-formed square steel tube 10 is heated and then hot- formed to a roughly formed square steel tube 15 approximating to the square steel tube having a normal dimension and shape, quality improvement of the square steel tube is made possible. The roughly formed square steel tube 15 is slowly cooled and then cold formed to a normal dimension and shape. Cold forming (final forming) is conducted at a state quality improvement is secured, that is, at a state hot forming has a reduced influence to quality of the square steel tube, both ends are hardly deformed to shorten a cut/removing length, a recessed is hardly generated to a flat part (four side plate parts), a shape of each corner part is made equal.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、たとえば建築用の
柱材に使用される大径で厚肉の角形鋼管(正方体形状、
直方体形状、五角形や六角形などの多角形状)を得るの
に採用される角形鋼管の製造方法に関するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-diameter, thick-walled rectangular steel pipe (for example, having a rectangular shape,
The present invention relates to a method for manufacturing a rectangular steel pipe used to obtain a rectangular parallelepiped shape, a polygonal shape such as a pentagon or a hexagon).

【0002】[0002]

【従来の技術】従来、この種の角形鋼管は、たとえば特
公昭58−13245号公報に見られる製造方法で得ら
れていた。すなわち、この従来方法は、一枚の厚肉鋼板
を長さ方向に移送して両側の開先加工を行ったのち、プ
レスにて、角形鋼管の四隅に相当する部分を曲げ加工し
て角形鋼管近似の形状に成形し、次いで近似角形鋼管を
複数段の成形ロールに通して角形鋼管形状に成形しつ
つ、開先突き合わせ面を順次仮付け溶接し、そして開先
部の内外面を自動溶接によって溶接したのち、歪み取り
を行うことで、大径の角形鋼管を得ている。
2. Description of the Related Art Conventionally, this kind of square steel pipe has been obtained by a manufacturing method disclosed in Japanese Patent Publication No. 58-13245. That is, in this conventional method, a single thick steel plate is transported in the length direction to perform beveling on both sides, and then, by pressing, portions corresponding to the four corners of the rectangular steel tube are bent and processed. Forming into an approximate shape, then passing the approximate square steel pipe through multiple stages of forming rolls to form a square steel pipe shape, sequentially tack-welding the groove butt surface, and automatically welding the inner and outer surfaces of the groove portion After welding, distortion removal is performed to obtain a large-diameter rectangular steel pipe.

【0003】しかし、上記した冷間成形により製造され
た角形鋼管は、角部やシーム溶接部の硬さが平板部(母
材)に比べてかなり高い値となるため、角部やシーム溶
接部の降伏強さが増大し、延性の低下をきたすことにな
り、以て機械的性質が不均一で残留応力が発生している
ことから、切削加工などを容易に行えない。また、各隅
部の形状(コーナR)はばらばらで均等になり難く、以
て角形鋼管の品質が悪いものになる。
[0003] However, in the square steel pipe manufactured by the cold forming described above, the hardness of the corner portion and the seam welded portion is considerably higher than that of the flat plate portion (base material). In this case, the yield strength increases, and the ductility decreases. As a result, the mechanical properties are non-uniform and residual stress is generated, so that cutting and the like cannot be easily performed. In addition, the shape (corner R) of each corner is irregular and difficult to be uniform, so that the quality of the rectangular steel pipe is poor.

【0004】そこで最近では、大径の角形鋼管に見合う
所定の径、板厚、長さの近似角形鋼管を、加熱炉に入れ
て加熱し、この加熱した近似角形鋼管を加熱炉から取り
出したのち、角形鋼管成形ミルで熱間成形して角形鋼管
を製造することが提供されている。
Therefore, recently, an approximate square steel pipe having a predetermined diameter, plate thickness, and length corresponding to a large-diameter square steel pipe is heated in a heating furnace, and the heated approximate square steel pipe is taken out of the heating furnace. It is provided that a square steel pipe is manufactured by hot forming in a square steel pipe forming mill.

【0005】[0005]

【発明が解決しようとする課題】しかし、上記した従来
の熱間成形による製造方法によると、近似角形鋼管は高
温加熱(A3 変態点以上)の状態で熱間成形されるこ
とから、熱間成形直後の角形鋼管は、その両端部が変形
し易くて切断装置による切断除去部分の長さを充分に取
らなければならず、成形によるロスが多いことになる。
また同様に熱間成形直後の角形鋼管は、その長さ方向の
全長において、平坦部(四辺板部)に凹みが生じ易く、
さらに各隅部の形状(コーナR)は均等になり難く、以
て角形鋼管の品質が悪いものになる。
[SUMMARY OF THE INVENTION However, according to the manufacturing method according to the molding between the conventional heat above, since it is hot-formed in a state of approximate square tube is high temperature heating (A 3 transformation point or higher), hot Immediately after forming, the rectangular steel pipe is easily deformed at both ends, so that the length of the portion to be cut and removed by the cutting device must be sufficiently long, resulting in a large loss due to forming.
Similarly, the square steel pipe immediately after hot forming is apt to have a dent in a flat portion (four-side plate portion) over its entire length in the length direction,
Further, the shape (corner R) of each corner is difficult to be uniform, so that the quality of the rectangular steel pipe is poor.

【0006】そこで本発明は、熱間成形による角形鋼管
の品質良化は維持し得るものでありながら、成形による
ロスを少なくし得、平坦部(四辺板部)に凹みが生じ難
く、さらに各隅部の形状は均等状にし得る角形鋼管の製
造方法を提供することを目的としたものである。
Accordingly, the present invention is to improve the quality of the rectangular steel pipe by hot forming, while reducing the loss due to forming, making it difficult for dents to occur in the flat part (four-sided plate part). An object of the present invention is to provide a method for manufacturing a square steel pipe in which corners can be made uniform.

【0007】[0007]

【課題を解決するための手段】前述した目的を達成する
ために、本発明の請求項1記載の角形鋼管の製造方法
は、鋼板を成形したのち突き合わせ溶接することにより
半成形角形鋼管を造管し、この半成形角形鋼管を加熱し
たのち、正規の寸法かつ形状の角形鋼管に近似の粗成形
角形鋼管に熱間成形し、この粗成形角形鋼管を徐冷した
のち、正規の寸法かつ形状に冷間成形することを特徴と
したものである。
According to a first aspect of the present invention, there is provided a method of manufacturing a rectangular steel pipe, comprising forming a steel sheet, forming a semi-formed square steel pipe by butt welding. Then, after heating the semi-formed square steel pipe, it is hot-formed into a roughly formed square steel pipe similar to a square steel pipe having a regular size and shape, and gradually cooled, and then gradually cooled to a regular size and shape. It is characterized by cold forming.

【0008】したがって請求項1の発明によると、半成
形角形鋼管を加熱成形することで、角形鋼管の品質良化
が可能となる。そして粗成形角形鋼管の冷間成形(最終
成形)は、品質良化を維持した状態で、すなわち熱間の
角形鋼管の品質への影響が軽い状態で行えるとともに、
その両端部が変形し難くて切断装置による切断除去部分
の長さを短くして行え、しかも平坦部(四辺板部)に凹
みが生じ難く、さらに各隅部の形状(コーナR)は均等
状にかつシャープなRに調整し得る。
Therefore, according to the first aspect of the present invention, the quality of the square steel pipe can be improved by heating and forming the semi-formed square steel pipe. The cold forming (final forming) of the roughly formed square steel pipe can be performed in a state where the quality is improved, that is, while the influence on the quality of the hot square steel pipe is light,
Both ends are hardly deformed, so that the length of the cut and removed portion by the cutting device can be shortened, and furthermore, the flat portion (quadrilateral plate portion) is not easily dented, and the shape of each corner (corner R) is uniform And sharp R can be adjusted.

【0009】[0009]

【発明の実施の形態】以下に、本発明の実施の形態を、
図1〜図7に基づいて説明する。図1に示すように、所
定長さの鋼板1を長さ方向1Aに搬送し、トリミング開
先加工機20に通して幅方向1Bにおける両側縁に開先
2を加工する。次いで、鋼板1を前段成形プレス21に
入れて、下金型22に対する上金型23の昇降動によ
り、側縁寄りの二箇所に直角状(90度またはほぼ90
度)の隅部3,4を折り曲げ成形する。その後、後段成
形プレス24に入れて、下金型25に対する上金型26
の昇降動により、中間の二箇所に鈍角(約105度)の
隅部5,6を折り曲げ成形する。
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described with reference to FIGS. As shown in FIG. 1, a steel plate 1 having a predetermined length is conveyed in a length direction 1A, and is passed through a trimming groove processing machine 20 to form grooves 2 on both side edges in a width direction 1B. Next, the steel sheet 1 is put into the preforming press 21, and the upper die 23 is moved up and down with respect to the lower die 22 to form two right angles (90 degrees or almost 90 degrees) near the side edge.
The corners 3 and 4 of (degree) are bent and formed. After that, it is put into a post-stage forming press 24, and the upper mold 26 with respect to the lower mold 25.
The corners 5 and 6 with obtuse angles (about 105 degrees) are bent and formed at two intermediate points by the vertical movement.

【0010】そして図2に示すように、仮付け溶接機2
7の部分で、四辺をロール28,29群(またはシリン
ダー)により外側から加圧することで、鈍角の隅部5,
6を直角状に成形しながら開先2どうしを突き合わせし
て、半成形角形鋼管10としながら、突き合わせ部に対
して仮付け溶接11を施工する。次いで、半成形角形鋼
管10を内面溶接機30に移して内面溶接12を施工す
る。さらに、半成形角形鋼管10を外面溶接機31に移
して外面溶接13を施工し、以て一辺に突き合わせ溶接
部(シーム溶接部)14を有する大径で厚肉の半成形角
形鋼管10を造管し得る。
[0010] Then, as shown in FIG.
At the portion 7, the four sides are pressed from the outside by the rolls 28 and 29 (or cylinders) to form obtuse corners 5.
While forming 6 into a right angle, the groove 2 is butted against each other to form a semi-formed square steel pipe 10, and the tack welding 11 is applied to the butted portion. Next, the semi-formed square steel pipe 10 is transferred to the inner surface welding machine 30 to perform the inner surface welding 12. Further, the semi-formed square steel pipe 10 is transferred to the outer surface welding machine 31 to perform the outer surface welding 13, thereby producing a large-diameter, thick-walled, semi-formed square steel pipe 10 having a butt weld (seam weld) 14 on one side. Can tube.

【0011】ここで半成形角形鋼管10は、後述する粗
成形角形鋼管よりも寸法や形状を大きくして造管してい
る。すなわち、対向された辺の外面間の寸法LLや各隅
部3〜6の半径形状LRを大きくして造管されている。
Here, the semi-formed square steel pipe 10 is made larger in size and shape than a coarsely-formed square steel pipe described later. That is, the pipe is formed by increasing the dimension LL between the outer surfaces of the opposing sides and the radius LR of each of the corners 3 to 6.

【0012】この半成形角形鋼管10は、図3、図4に
示すように、加熱炉32に搬入され、この加熱炉32内
にて搬送されながら、全体(所定箇所)がA3 変態点
以上に高温加熱Hされる。そして加熱された半成形角形
鋼管10は加熱炉32から取り出されたのち、図3、図
5に示すように、熱間成形機33に搬入される。
As shown in FIGS. 3 and 4, the semi-formed square steel pipe 10 is carried into a heating furnace 32 and, while being conveyed in the heating furnace 32, the whole (predetermined portion) is at or above the A 3 transformation point. To a high temperature H. Then, the heated semi-formed square steel pipe 10 is taken out of the heating furnace 32 and then carried into a hot forming machine 33 as shown in FIGS.

【0013】この熱間成形機33では、複数の平形状ロ
ール34,35などを介して半成形角形鋼管10を絞り
状に熱間成形(成形温度、A3 変態点以上)するもの
で、最終製品である角形鋼管が正規の寸法かつ形状(コ
ーナのRなど)で仕上がるように、半成形角形鋼管10
を、正規の寸法かつ形状の角形鋼管に近似の粗成形角形
鋼管15に熱間成形する。
[0013] The present in the hot-forming machine 33, the hot molding (molding temperature, A 3 transformation point or above) via a plurality of flat-shaped roll 34, 35 to form aperture half-formed square steel pipe 10 to the final The semi-formed square steel pipe 10 is manufactured so that the square steel pipe as a product is finished in a regular size and shape (such as corner radius).
Is hot formed into a roughly formed square steel pipe 15 similar to a square steel pipe having a regular size and shape.

【0014】なお、熱間成形機33での熱間成形は、複
数段で徐々に絞り成形するのが好ましいが、その段数は
任意であり、場合によっては単数段でもよい。ここで粗
成形角形鋼管15は、前述したように半成形角形鋼管1
0よりも寸法や形状を小さくして、すなわち、対向され
た辺の外面間の寸法Lや各隅部3〜6の半径Rを、半成
形角形鋼管10の外面間の寸法LLや各隅部3〜6の半
径LRよりも小さくして熱間成形されている。しかし、
粗成形角形鋼管15は、後述する角形鋼管(最終製品)
よりも寸法や形状を大きくして熱間成形されている。
In the hot forming by the hot forming machine 33, it is preferable to gradually draw in a plurality of stages, but the number of stages is arbitrary, and in some cases, a single stage may be employed. Here, the rough-formed square steel pipe 15 is, as described above, a semi-formed square steel pipe 1.
0, that is, the dimension L between the outer surfaces of the opposing sides and the radius R of each of the corners 3 to 6 are reduced by the dimension LL between the outer surfaces of the semi-formed square steel pipe 10 and each of the corners. It is hot formed with a radius smaller than the radius LR of 3-6. But,
The rough-formed square steel pipe 15 is a square steel pipe (final product) described later.
It is hot-formed with larger dimensions and shape.

【0015】この熱間成形された粗成形角形鋼管15
は、図3、図6に示すように、冷却床36に受け取ら
れ、この冷却床36において空冷形式で放熱I、すなわ
ち徐冷される。冷却床36において常温にまで(または
その近くまで)徐冷された粗成形角形鋼管15は、図
3、図7に示すように、冷間成形機37に搬入される。
この冷間成形機37では、複数の平形状ロール38など
を介して冷間成形(常温成形)を行うもので、粗成形角
形鋼管15に対して最終段の絞り成形が行われ、以て正
規の寸法かつ形状で最終製品となる大径の角形鋼管(鋼
管)16が冷間成形される。
The hot-formed roughly formed square steel pipe 15
As shown in FIGS. 3 and 6, the heat is received by the cooling floor 36, where the heat is radiated I, that is, gradually cooled, in an air-cooled manner. The roughly formed rectangular steel pipe 15 gradually cooled to (or close to) normal temperature in the cooling floor 36 is carried into a cold forming machine 37 as shown in FIGS.
In this cold forming machine 37, cold forming (normal temperature forming) is performed via a plurality of flat rolls 38 and the like. A large-diameter rectangular steel pipe (steel pipe) 16 which is a final product having the dimensions and the shape described above is cold-formed.

【0016】なお、冷間成形機37での冷間成形は、複
数段で徐々に絞り成形するのが好ましいが、その段数は
任意であり、場合によっては単数段でもよい。ここで角
形鋼管16は、前述したように粗成形角形鋼管15より
も寸法や形状を小さくして、すなわち、対向された辺の
外面間の寸法SLや各隅部3〜6の半径SRを、粗成形
角形鋼管15の外面間の寸法Lや各隅部3〜6の半径R
よりも小さくして冷間成形されている。
In the cold forming by the cold forming machine 37, it is preferable to gradually draw in a plurality of stages, but the number of stages is optional, and in some cases, a single stage may be used. Here, the rectangular steel pipe 16 is made smaller in size and shape than the rough-formed rectangular steel pipe 15 as described above, that is, the dimension SL between the outer surfaces of the opposed sides and the radius SR of each corner 3 to 6 are set as follows. The dimension L between the outer surfaces of the roughly formed rectangular steel pipe 15 and the radius R of each of the corners 3 to 6
Cold formed.

【0017】冷間成形された角形鋼管4は、図示してい
ない先端切断装置、後端切断装置、洗浄装置、防錆装置
へと搬送され、それぞれで処理されたのち、製品として
ストレージされる。
The cold-formed square steel pipe 4 is conveyed to a leading end cutting device, a trailing end cutting device, a washing device, and a rust prevention device (not shown), and is processed and stored as a product.

【0018】前述したように、熱間成形や冷間成形によ
り、外面間の寸法はLL>L>SLと変化し、また各隅
部3〜6の半径はLR>R>SRと変化する。なお鋼管
は、加熱炉32での加熱により全体が膨張され、そして
冷却床36での冷却により全体が収縮されるが、前述し
たLL>L>SLとLR>R>SRとの変化には、かか
る膨張、収縮は計算されている。
As described above, the dimension between the outer surfaces changes as LL>L> SL and the radius of each of the corners 3 to 6 changes as LR>R> SR by hot forming or cold forming. The entire steel pipe is expanded by heating in the heating furnace 32 and contracted entirely by cooling in the cooling floor 36. However, in the above-described change between LL>L> SL and LR>R> SR, Such expansion and contraction are calculated.

【0019】前述したように、半成形角形鋼管10を加
熱成形することで、角形鋼管の品質良化が可能となる。
そして粗成形角形鋼管15の冷間成形(最終成形)は、
品質良化を維持した状態で、すなわち熱間の角形鋼管の
品質への影響が軽い状態で行えるとともに、その両端部
が変形し難くて切断装置による切断除去部分の長さを短
くして、成形によるロスが少ない状態で行え、しかも平
坦部(四辺板部)に凹みが生じ難く、さらに各隅部の形
状(コーナR)は均等状にかつシャープなRに調整し得
ることになり、以て品質の良い角形鋼管を製造し得る。
As described above, the quality of the square steel pipe can be improved by heating and forming the semi-formed square steel pipe 10.
And the cold forming (final forming) of the roughly formed square steel pipe 15 is as follows.
While maintaining the quality improvement, that is, in the state where the influence on the quality of the hot rectangular steel pipe is light, it is difficult to deform at both ends, and the length of the cut removal part by the cutting device is shortened to form. In this case, the loss can be reduced, the flat portion (quadrilateral plate portion) is hardly dented, and the shape (corner R) of each corner can be adjusted uniformly and sharply. High quality square steel pipe can be manufactured.

【0020】次に、本発明の別の実施の形態を図8に基
づいて説明する。すなわち、上述した実施の形態では、
一枚の鋼板1を使用し、一辺に突き合わせ溶接部14を
有する大径で厚肉の角形鋼管(製品)16を製造してい
るが、これは図8の(A)に示すように、二枚の鋼板を
使用し、二辺に突き合わせ溶接部14を有する大径で厚
肉の角形鋼管16を製造してもよい。
Next, another embodiment of the present invention will be described with reference to FIG. That is, in the above-described embodiment,
A large-diameter, thick-walled rectangular steel pipe (product) 16 having a butt welded portion 14 on one side is manufactured using one steel sheet 1, and as shown in FIG. A large-diameter, thick-walled rectangular steel pipe 16 having butt welds 14 on two sides may be manufactured using two steel plates.

【0021】また、上述した実施の形態では、正方体形
状の角形鋼管16を製造しているが、これは直方体形状
の角形鋼管16を製造してもよく、さらに図8の(B)
に示すような五角形形状の角形鋼管16や、図8の
(C)に示すような六角形形状の角形鋼管16など、各
種の多角形状の角形鋼管16を製造してもよい。
Further, in the above-described embodiment, the rectangular steel pipe 16 having a rectangular parallelepiped shape is manufactured. Alternatively, the rectangular steel pipe 16 having a rectangular parallelepiped shape may be manufactured. Further, FIG.
Various polygonal rectangular steel pipes 16 may be manufactured, such as a pentagonal rectangular steel pipe 16 shown in FIG. 8 and a hexagonal rectangular steel pipe 16 shown in FIG.

【0022】上記した実施の形態では、大径で厚肉の角
形鋼管16を製造しているが、これは大径で薄肉の角形
鋼管、小径で厚肉の角形鋼管、小径で薄肉の角形鋼管な
どの製造であってもよい。
In the above-described embodiment, the large-diameter, thick-walled rectangular steel pipe 16 is manufactured. The large-diameter, thick-walled rectangular steel pipe, the small-diameter, thick-walled rectangular steel pipe, and the small-diameter, thin-walled square steel pipe are manufactured. And the like.

【0023】上記した実施の形態では、前段成形プレス
21や後段成形プレス24などプレス方式で鋼板1の成
形を行っているが、これはロール方式で鋼板1の成形を
行ってもよい。
In the above-described embodiment, the steel sheet 1 is formed by a press method such as the pre-press 21 and the post-press 24. However, the steel sheet 1 may be formed by a roll method.

【0024】上記した実施の形態では、半成形角形鋼管
10を加熱炉32に搬入して、全体をA3 変態点以上
に高温加熱Hしているが、これは隅部3〜6の付近(所
定箇所)のみ高温加熱Hしたのち、熱間成形機33に搬
入させてもよい。
In the above-described embodiment, the semi-formed square steel pipe 10 is carried into the heating furnace 32 and the whole is heated to a high temperature H at or above the A 3 transformation point. After heating only at a predetermined location (high temperature H), it may be carried into the hot forming machine 33.

【0025】[0025]

【発明の効果】上記した本発明の請求項1によると、半
成形角形鋼管を加熱成形することで、角形鋼管の品質良
化を可能にできる。そして粗成形角形鋼管の冷間成形
(最終成形)は、品質良化を維持した状態で、すなわち
熱間の角形鋼管の品質への影響が軽い状態で行うことが
できるとともに、その両端部が変形し難くて切断装置に
よる切断除去部分の長さを短くして、成形によるロスが
少ない状態で行うことができ、しかも平坦部(四辺板
部)に凹みが生じ難く、さらに各隅部の形状(コーナ
R)は均等状に調整できることになり、以て品質の良い
角形鋼管、特に大径で厚肉の場合に好適な角形鋼管を製
造できる。
According to the first aspect of the present invention, the quality of the rectangular steel pipe can be improved by heating and molding the semi-formed rectangular steel pipe. The cold forming (final forming) of the roughly formed square steel pipe can be performed in a state where the quality is maintained, that is, while the influence on the quality of the hot square steel pipe is light, and both ends thereof are deformed. It is difficult to cut and remove the length of the cut and removed portion by the cutting device, so that it can be performed with less loss due to molding. In addition, the flat portion (four-sided plate portion) is hardly dented and the shape of each corner ( The corner R) can be adjusted evenly, so that it is possible to produce a high quality square steel pipe, particularly a square steel pipe suitable for a large diameter and thick wall.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明の実施の形態の一例を示し、角形鋼管の
製造方法における鋼板成形工程までの説明図である。
FIG. 1 shows an example of an embodiment of the present invention and is an explanatory diagram up to a steel sheet forming step in a method for manufacturing a rectangular steel pipe.

【図2】同角形鋼管の製造方法における半成形角形鋼管
の造管工程までの説明図である。
FIG. 2 is an explanatory view up to a pipe forming step of a semi-formed square steel pipe in a method of manufacturing the same square steel pipe.

【図3】同角形鋼管の製造方法における最終工程までの
説明図である。
FIG. 3 is an explanatory view up to a final step in a method for manufacturing a square steel pipe.

【図4】同角形鋼管の製造方法における加熱工程の正面
図である。
FIG. 4 is a front view of a heating step in the method for manufacturing a rectangular steel pipe.

【図5】同角形鋼管の製造方法における熱間成形工程の
正面図である。
FIG. 5 is a front view of a hot forming step in the method of manufacturing a square steel pipe.

【図6】同角形鋼管の製造方法における冷却工程の正面
図である。
FIG. 6 is a front view of a cooling step in the method of manufacturing the rectangular steel pipe.

【図7】同角形鋼管の製造方法における冷間成形工程の
正面図である。
FIG. 7 is a front view of a cold forming step in the method for manufacturing a rectangular steel pipe.

【図8】本発明の別の実施の形態を示し、(A)は二枚
の鋼板を使用した角形鋼管の正面図、(B)は五角形形
状の角形鋼管の正面図、(C)は六角形形状の角形鋼管
の正面図である。
8A and 8B show another embodiment of the present invention, wherein FIG. 8A is a front view of a square steel pipe using two steel plates, FIG. 8B is a front view of a pentagonal square steel pipe, and FIG. It is a front view of a square steel pipe of a square shape.

【符号の説明】 1 鋼板 3 隅部 4 隅部 5 隅部 6 隅部 10 半成形角形鋼管 14 突き合わせ溶接部 15 粗成形角形鋼管 16 角形鋼管(製品) 21 前段成形プレス 24 後段成形プレス 27 仮付け溶接機 30 内面溶接機 31 外面溶接機 32 加熱炉 33 熱間成形機 36 冷却床 37 冷間成形機 H 高温加熱 I 放熱[Description of Signs] 1 Steel plate 3 Corner 4 Corner 5 Corner 6 Corner 10 Semi-formed square steel pipe 14 Butt weld 15 Rough-formed square steel pipe 16 Square steel pipe (product) 21 Pre-stage press 24 Post-stage press 27 Temporary attachment Welding machine 30 Internal welding machine 31 External welding machine 32 Heating furnace 33 Hot forming machine 36 Cooling floor 37 Cold forming machine H High temperature heating I Heat radiation

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 鋼板を成形したのち突き合わせ溶接する
ことにより半成形角形鋼管を造管し、この半成形角形鋼
管を加熱したのち、正規の寸法かつ形状の角形鋼管に近
似の粗成形角形鋼管に熱間成形し、この粗成形角形鋼管
を徐冷したのち、正規の寸法かつ形状に冷間成形するこ
とを特徴とする角形鋼管の製造方法。
1. A semi-formed square steel pipe is formed by butt welding after forming a steel sheet, and after heating the semi-formed square steel pipe, it is converted into a roughly formed square steel pipe similar to a square steel pipe having a regular size and shape. A method for manufacturing a square steel pipe, comprising hot forming, gradually cooling the roughly formed square steel pipe, and then cold forming into a regular size and shape.
JP34045297A 1997-12-11 1997-12-11 Method of manufacturing square steel pipe Expired - Lifetime JP3292829B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP34045297A JP3292829B2 (en) 1997-12-11 1997-12-11 Method of manufacturing square steel pipe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP34045297A JP3292829B2 (en) 1997-12-11 1997-12-11 Method of manufacturing square steel pipe

Publications (2)

Publication Number Publication Date
JPH11169947A true JPH11169947A (en) 1999-06-29
JP3292829B2 JP3292829B2 (en) 2002-06-17

Family

ID=18337106

Family Applications (1)

Application Number Title Priority Date Filing Date
JP34045297A Expired - Lifetime JP3292829B2 (en) 1997-12-11 1997-12-11 Method of manufacturing square steel pipe

Country Status (1)

Country Link
JP (1) JP3292829B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001212615A (en) * 2000-02-04 2001-08-07 Ricoh Co Ltd Method and apparatus for manufacturing pipe, pipe manufactured by them and image forming device using it

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001212615A (en) * 2000-02-04 2001-08-07 Ricoh Co Ltd Method and apparatus for manufacturing pipe, pipe manufactured by them and image forming device using it

Also Published As

Publication number Publication date
JP3292829B2 (en) 2002-06-17

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