JP2006334633A - Method and equipment for manufacturing circular steel pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a circular steel pipe by which thin and thick circular steel pipes are obtained efficiently. <P>SOLUTION: A steel plate 1 having a prescribed width is successively stepwise hot-formed from a circular-arcuate plate body 1B into a round-shaped steel pipe 1C by a plurality of stages of roll type forming means 21, 26, 31, 36, 41 after wholly heating the steel plate up to a prescribed temperature or the vicinity of it by a heating means 16 and, next, passing through a hot-forming part 20 while conveying the heated steel plate 1A in the length direction. The circular steel pipe 5 is manufactured by joining 4 the free ends of the round-shaped steel pipe 1C by welding in the state that the free ends are opposed to each other while restraining the round-shaped steel pipe 1C from the outer periphery. By performing the hot-forming by the plurality of stages of the roll type forming means while conveying the heated steel plate in the length direction, the forming from the steel plate into the round-shaped steel pipe is performed like the flow production and, by joining between the free ends of the round-shaped steel pipe by welding, the thin and thick circular steel pipes are manufactured efficiently and at a low cost. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a round steel pipe used for a steel pipe column (post) of a steel structure, for example, and a manufacturing equipment for the round steel pipe.

  Conventionally, in order to obtain this type of round steel pipe, it is possible to manufacture a round steel pipe by cold forming the steel sheet and then welding and then heat the round steel pipe to perform post heat treatment (such as annealing). Is provided. However, according to this conventional configuration, since the steel sheet is cold formed, it is difficult to manufacture a thick round steel pipe, and the thickness becomes a thin round steel pipe having a maximum thickness of about 9 mm.

Then, the following structures are provided as what can manufacture a thick round steel pipe. That is, the semi-formed round steel pipe is half-formed (cold-formed) with a slightly larger diameter by press-forming the steel plate and then butting and welding one place. This semi-formed round steel pipe is heated in a heating means (such as a heating furnace), and the outer peripheral shape is hot-formed (shaped) in a forming means (such as a forming roll device). Thereby, the round steel pipe of the desired diameter is obtained (for example, refer patent document 1).
Japanese Patent Laying-Open No. 2001-303661 (5th page, FIG. 13)

  However, according to the above-described conventional configuration, for example, it is suitable for obtaining a thick round steel pipe having a plate thickness of 50 mm. However, hot forming by a forming means is a drawing for a thick semi-formed round steel pipe. Since the molding is performed, the molding time becomes long, and the production efficiency becomes poor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method of manufacturing a round steel pipe that can efficiently obtain a thin or thick round steel pipe.
The invention according to claim 5 is intended to provide a manufacturing facility for a round steel pipe which can be simply configured as a whole.

  In order to achieve the above-described object, a method for manufacturing a round steel pipe according to claim 1 of the present invention comprises heating a steel plate having a predetermined width to a predetermined temperature or its vicinity by a heating means, and then heating the heated steel plate. While being transported in the length direction, it is passed through the hot forming part, and is hot formed in stages from the circular arc plate to the round steel pipe by a multi-stage roll forming means. It is characterized in that it is welded and joined with its free ends facing each other while restraining.

  Therefore, according to the invention of claim 1, by hot forming with a plurality of roll-type forming means while transporting the heated steel plate in the length direction, the forming from the steel plate to the round steel pipe can be performed in a flow work, and A round steel pipe can be manufactured by welding the free ends of the round steel pipe.

  Moreover, the manufacturing method of the round steel pipe of Claim 2 of this invention is the structure of Claim 1 mentioned above, The roll type | mold shaping | molding means of each step | paragraph is hot forming, restraining by a roll group, It is a thing.

Therefore, according to the invention of claim 2, hot forming in the roll-type forming means at each stage can be performed stably and accurately.
And the manufacturing method of the round steel pipe of Claim 3 of this invention is the structure of Claim 1 or 2 mentioned above, The length of a steel plate is a length corresponding to a beam material connection part, It is characterized by the above-mentioned. It is what.

Therefore, according to the invention of claim 3, the round steel pipe for the beam connecting portion can be efficiently manufactured.
Furthermore, the method for manufacturing a round steel pipe according to claim 4 of the present invention is characterized in that, in the configuration according to claim 1 or 2, the length of the steel sheet is a length corresponding to the steel pipe column. It is.

Therefore, according to the invention of claim 4, a steel pipe column made of a round steel pipe can be efficiently manufactured.
And the manufacturing equipment of the round steel pipe of Claim 5 of this invention is the hot forming in steps, conveying the heating steel plate to the predetermined direction or the heating means which heats a steel plate to the predetermined temperature or its vicinity. Then, a hot-formed part composed of a multi-stage roll-type forming means to be finally formed into a round-shaped steel pipe is weld-bonded in a state in which the free ends are opposed to each other while restraining the round-shaped steel pipe from the outer periphery. It is characterized by comprising welding means.

  Therefore, according to the invention of claim 5, the manufacturing equipment capable of realizing the manufacturing method of claims 1 to 4 can be provided with a simple configuration as a whole.

  According to the first aspect of the present invention described above, the hot-rolled steel sheet is hot-formed by a multi-stage roll-type forming means while transporting the heated steel sheet in the length direction, thereby forming the steel sheet into a round-shaped steel pipe as a flow work. It is possible to manufacture thin and thick round steel pipes efficiently and inexpensively by welding the free ends of the round steel pipes.

According to the second aspect of the present invention, the hot forming in the roll-type forming means at each stage can be performed stably and accurately.
According to the third aspect of the present invention, the round steel pipe for the beam connecting portion can be manufactured efficiently and inexpensively.

Furthermore, according to claim 4 of the present invention described above, a steel pipe column made of a round steel pipe can be manufactured efficiently and inexpensively.
And according to Claim 5 of this invention mentioned above, the whole manufacturing equipment which can implement | achieve the manufacturing method of Claims 1-4 can be comprised simply and provided.

[Embodiment]
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a steel plate 1 having a predetermined width W and a predetermined length L that forms a beam connecting portion (panel zone) is prepared. Here, the plate thickness T of the steel plate 1 is 9 to 50 mm, and the predetermined width W is set to a length corresponding to obtaining a round steel pipe for a beam connecting portion having an outer diameter of 180 to 600 mm.

  As shown in FIG. 2, in the conveyance path 10 for conveying the steel sheet 1 in the length direction, the trimming groove processing machine 15, the heating and heating means 16, and the hot forming unit 20 are sequentially arranged from the upper side to the lower side. And the brushing part 46 and the welding means 50 are provided. The hot forming section 20 is provided with five-stage (multiple-stage) roll-type forming means 21, 26, 31, 36, 41.

While the steel plate 1 is transported on the transport path 10, that is, as shown in FIG. 3 (a), it is supported by the roller conveyor 11 and determined by the left and right width determining rolls 12 and transported on the transport path 10. First, the groove 2 is processed on both side edges in the width direction by passing through the trimming groove processing machine 15. Then the steel sheet 1, for example through a heating unit 16 consisting of a combustion heating type of placed in a heating furnace, the whole heated to near (front and back) of the A ₃ transformation point, which is an example of a predetermined temperature (e.g. 850-1,050 ° C.) To do. Then, the heated steel plate 1A is passed through the hot forming section 20 while being conveyed in the length direction, and hot formed by the roll-type roll forming means 21, 26, 31, 36, 41.

  That is, as shown in FIG. 3 (b), in the roll forming means 21 in the first stage (first stage), the heated steel sheet 1A is sandwiched from above and below by the lower outer roll 22 and the upper inner roll 23. Thus, hot forming is performed while being restricted by the rolls 22 and 23 group. At that time, the outer roll 22 is formed on the concave arc-shaped molding surface 22a having a larger diameter toward the end, and the inner roll 23 is formed on the convex arc-shaped molding surface 23a having a smaller diameter toward the end. The steel plate 1A is hot-formed in an arc shape whose both ends are upward with respect to the center in the width direction.

  Next, in the second-stage roll-type forming means 26, as shown in FIG. 3C, heating is performed by the lower outer roll 27 group and the upper inner roll group 28 in three rows (plural rows) in the left-right direction. By sandwiching the steel plate 1A from above and below, it is hot-formed while being restrained by the rolls 27 and 28 group. At that time, the concave arc-shaped molding surface 27a of the outer roll 27 group and the convex arc-shaped molding surface 28a of the inner roll 28 are used as the concave arc-shaped molding surface 22a or the convex arc-shaped in the roll-type molding means 21 at the first stage. By changing the shape of the arc-shaped molding surface with respect to the molding surface 23a, the arc-shaped molding surface 1B is hot-molded so as to have a deep arc shape.

  In the third-stage roll-type forming means 31, as shown in FIG. 4A, each of the arcuate plate-like body 1B is composed of three rows (a plurality of rows) of outer rolls 32 and inner rolls 33 in the left-right direction. Is formed from above and below, and is hot-formed while being restrained by the rolls 32 and 33 group. At that time, the concave arc-shaped molding surface 32a of the outer roll 32 group and the convex arc-shaped molding surface 33a of the inner roll 33 group are used as the concave arc-shaped molding surface 27a and the convex circle of the second-stage roll-type molding means 26. By changing the shape of the arc-shaped forming surface with respect to the arc-shaped forming surface 28a, hot forming is performed so as to form a deeper arc-shaped plate-like body 1B.

  Next, in the roll type forming means 36 in the fourth stage, as shown in FIG. 4B, the arc plate-like body 1B is formed by the outer rolls 37 in three rows (a plurality of rows) in the left-right direction, that is, the lower and left and right sides. By abutting from the outside, hot forming is performed while being restrained by the group of rolls 37. At that time, by changing the shape of the arc-shaped molding surface of the concave arc-shaped molding surface 37a of the outer roll 37 group with respect to the concave arc-shaped molding surface 32a of the third-stage roll-type molding means 31 described above. The arcuate plate-like body 1B is hot-formed so as to have a round shape.

  In the roll forming means 41 in the final stage (fifth stage), as shown in FIG. 5A, a circular arc plate is formed by four rows (a plurality of rows), that is, a group of outer rolls 42 in the vertical and horizontal directions. Hot forming is performed while being restrained by the group of rolls 42 by bringing the body 1B into contact with the outside. At that time, by changing the shape of the arcuate molding surface of the concave arcuate molding surface 42a of the outer roll 42 group with respect to the concave arcuate molding surface 37a in the roll type molding means 36 of the fourth stage described above. The circular arc plate-like body 1B is hot-formed so as to become a round steel pipe 1C. In addition, a large-diameter disk-shaped restricting roll portion 42A is formed at the central portion of the upper outer roll 42, and both side edges (edges) are in contact with and restrained by the left and right side surfaces of the restricting roll portion 42A. Thus, the round steel pipe 1C is hot-formed stably and accurately in a state approaching a perfect circle.

  In this way, the heated steel sheet 1A heated and carried into the hot forming section 20 is sequentially moved from the circular arc shaped plate 1B to the round steel pipe 1C by the roll forming means 21, 26, 31, 36, 41 group. In this case, the hot forming is performed in a rolling manner gradually (stepwise) by the roll forming means 21, 26, 31, 36, 41 of a plurality of stages. That is, the hot-rolled steel sheet 1A is hot-formed by a plurality of roll-type forming means 21, 26, 31, 36, 41 while transporting the heated steel sheet 1A in the length direction, so that the forming from the steel sheet 1 to the round-shaped steel pipe 1C is performed as a flow work. Can be done.

  Then, the hot-formed round steel pipe 1C is carried into the brushing section 46 as shown in FIG. 2, and the groove 2 is subjected to brushing or the like as shown in FIG. Remove the mill scale. That is, in the brushing unit 46, the round steel pipe 1C is abutted from the outside by the four rows (a plurality of rows) of outer rolls 47 in the upper, lower, left, and right sides, and is brushed while being restrained by the rolls 47. At that time, the concave arc-shaped molding surface 47a of the outer roll 47 group is made equivalent to the concave arc-shaped molding surface 42a in the roll-type molding means 41 in the final stage described above. Further, a brush 48 is provided at a central portion of the upper outer roll 47, and the brush 48 is brushed against the groove 2 by being brought into sliding contact with the groove 2 of the round steel pipe 1C.

  In this way, the round steel pipe 1C brushed with respect to the groove 2 is carried into the welding means 50, and the groove (free end) 2 is opposed to each other while restraining the round steel pipe 1C from the outer periphery. Welding connection is performed in the state. The welding means 50 includes an upper temporary welding portion 51 and a lower main welding portion 56. Here, in the tack welded portion 51 and the main welded portion 56, as shown in FIG. 6A, the round steel pipe 1C is constrained from the outer periphery by a group of outer rolls 52 in three rows (a plurality of rows) of lower and left and right. Then, tack welding or main welding is performed in a state where the groove (free end) 2 is substantially in contact. At that time, the concave arc-shaped molding surface 52a of the outer roll 52 group is made equivalent to the concave arc-shaped molding surface 47a of the brushing portion 46 described above.

That is, in the tack welding section 51, the round steel pipe 1C is constrained from the outer periphery by the outer roll 52 group, and the tack welding 4A is performed in a state where the groove (free end) 2 is substantially in contact. Next, in the main welded portion 56, the round steel pipe 1C is restrained from the outer periphery by the outer roll 52 group, and the welded joint 4 is formed. In this way, by performing the welding connection 4 using the groove 2, as shown in FIG.
A round steel pipe (final product) 5 having a similar outer diameter Φ and a length L that forms a beam connecting portion can be manufactured for a long square steel pipe (described later). In addition, the round steel pipe 5 taken out from the place of the welding means 50 is conveyed to a correction device, a front end cutting device, a rear end cutting device, a cleaning device, and a rust prevention device (not shown) as necessary. After being processed, it is stored as a product.

  The round steel pipe 5 for the beam connecting portion thus obtained is used as a part of a steel pipe column in a steel structure. That is, as shown in FIGS. 7 and 8, the steel structure 60 includes a steel pipe column 61 and a beam member 65 connected to a beam member connecting portion (panel zone) of the steel tube column 61. The steel pipe column 61 is constituted by a long round steel pipe (long column) 62 and a round steel pipe (column) 5 for a beam connecting portion, and the steel pipe column 61 is long in its length direction. It is cut (divided) into a round round steel pipe 62 group and a round steel pipe 5 group for a beam connecting portion. Here, the long round steel pipe 62 is cold-formed, and the thickness t is 6 to 22 mm, which is thinner than the thickness T of the round steel pipe 5, that is, t <T. As described above, the round steel pipe 5 is hot-formed to the same outer diameter Φ with respect to the outer diameter of the long round steel pipe 62.

  The lower end of the round steel pipe 5 is butt welded 63 to the upper end of the lower long round steel pipe 62, and the lower end of the upper long round steel pipe 62 is butt welded to the upper end of the round steel pipe 5. 63. In addition, when performing butt welding 63, the backing material 64 is interposed on the inner surface side of the long round steel pipe 62. The beam material (mainly H-shaped steel material) 65 is connected to the steel pipe column 61 formed in this way by welding 66 the free end of the beam material 65 to the round steel pipe 5 for the beam material connecting portion. Even when this welding 66 is performed, a backing material 67 is interposed.

  The steel structure 60 configured in this manner is designed to remove residual stress and restore toughness to a part of the steel pipe column 61, that is, the round steel pipe 5 for the beam connecting portion, and torsion, bending, and deformation. A homogeneous hot-formed steel pipe that hardly occurs can be adopted, and this hot-formed steel pipe can be obtained efficiently and inexpensively, so that the steel structure 60 can be constructed at a significant cost reduction. A hot-formed steel pipe is used as the round steel pipe 5 for the beam connecting portion, and a cold-formed steel pipe is used as the long round steel pipe 62. As the long round steel pipe 62, heat treatment is used. Steel pipes and hot-formed steel pipes may be used.

In the above embodiment, the entire heated through heating means 16 before hot forming, although the neighborhood (front and rear) of the A ₃ transformation point, which is an example of a predetermined temperature (e.g. 850-1,050 ° C.), heated The heating temperature by the means 16 is arbitrarily set.

  In the embodiment described above, a form in which the hot forming section 20 is provided with five (multiple) roll forming means 21, 26, 31, 36, 41 is shown. The number of stages is arbitrarily set. In addition, the arrangement of roll groups, the number of rolls, the roll shape, and the like in each roll-type forming means are arbitrarily determined.

  In the above-described embodiment, the groove 2 is processed through the trimming groove processing machine 15 while the steel plate 1 is conveyed on the conveyance path 10, but this may be a form in which the groove is not processed. Good.

  In the above-described embodiment, the round steel pipe 5 for the beam material connecting portion is manufactured using the steel plate 1 having the length L that forms the beam material connecting portion (panel zone). After manufacturing a long round steel pipe using a steel plate, this long round steel pipe is cut into a length L that forms a beam material connecting portion to form a round steel pipe 5 for the beam material connecting portion. You may make it obtain. Further, a round steel pipe having a length corresponding to the steel pipe column may be manufactured, and this round steel pipe may be used for the steel pipe column.

BRIEF DESCRIPTION OF THE DRAWINGS It is Embodiment 1 of this invention, and is a perspective view of the steel plate used for manufacture of a round steel pipe. It is a schematic explanatory drawing which shows the process in the manufacturing method and manufacturing equipment of the same round steel pipe. In the manufacturing method and manufacturing equipment of the same round steel pipe, (a) is a front view when a steel plate is conveyed, (b) is a front view of a roll-type forming means part at the first stage, and (c) is a second-stage roll. It is a front view of a type | mold shaping | molding means part. In the manufacturing method and manufacturing equipment of the same round steel pipe, (a) is a front view of a third-stage roll-type forming means portion, and (b) is a front view of a fourth-stage roll-type forming means portion. In the manufacturing method and manufacturing equipment of the same round steel pipe, (a) is a front view of the roll-type forming means portion of the final stage, and (b) is a front view of the brushing portion. In the manufacturing method and manufacturing equipment of the round steel pipe, (a) is a front view of a welding means portion, and (b) is a front view of the manufactured round steel pipe. It is a partially cutaway perspective view of a steel structure using a round steel pipe for a beam connecting part manufactured in the same manner. It is a vertical front view of the principal part of the steel structure using the round steel pipe for the beam connection part manufactured in the same.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel plate 1A Heated steel plate 1B Arc plate-like body 1C Round shaped steel pipe 2 Groove 4 Welded joint 5 Round steel pipe 10 for beam connection part Conveyance path 15 Trimming bevel processing machine 16 Heating means 20 Hot forming part 21 Beginning Stage (first stage) roll forming means 22 Outer roll 23 Inner roll 26 Second stage roll forming means 27 Outer roll 28 Inner roll 31 Third stage roll forming means 32 Outer roll 33 Inner roll 36 Four stages Roll type forming means 37 for the outer roll 41 Roll type forming means 42 for the final stage (fifth stage) 42 Outer roll 42A Restricting roll part 46 Brushing part 47 Outer roll 48 Brush 50 Welding means 51 Temporary welding part 52 Outer roll 56 Welded portion 60 Steel structure 61 Steel tube column 62 Long round steel tube 65 Beam material W Predetermined width L of steel plate 1 Length T corresponding to beam material connecting portion Steel plate 1 and round shape Thickness Φ outer diameter of the plate thickness t Nagashakumaru shaped steel 62 tube 5

Claims (5)

  A steel plate having a predetermined width is heated to a predetermined temperature or the vicinity thereof by a heating means, and then passed through a hot forming portion while conveying the heated steel plate in the length direction, and a circular plate is formed by a multi-stage roll type forming means. The round steel pipe is characterized in that it is hot-formed in stages from a cylindrical body to a round steel pipe and is welded and joined with the free ends facing each other while restraining the round steel pipe from the outer periphery. Manufacturing method.   The method of manufacturing a round steel pipe according to claim 1, wherein the roll-type forming means of each stage is hot-formed while being constrained by a roll group.   The method of manufacturing a round steel pipe according to claim 1 or 2, wherein the length of the steel plate is a length corresponding to the beam material connecting portion.   The method for producing a round steel pipe according to claim 1 or 2, wherein the length of the steel plate is a length corresponding to the steel pipe column. Heating means that heats the steel plate to the specified temperature or its vicinity, and multi-stage roll forming that finally forms a round steel pipe by hot forming stepwise while conveying the heated steel plate in the length direction An apparatus for manufacturing a round steel pipe, comprising: a hot-formed portion comprising means; and welding means for constraining the round steel pipe from the outer periphery and welding and joining the free ends thereof to face each other.

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