JP2020006387A - Manufacturing device of round steel pipe and round steel pipe manufacturing facility - Google Patents

Abstract

To provide a manufacturing device which can manufacture a round steel pipe from a steel plate by a simplified facility constitution and a simple manufacturing process, and a round steel pipe manufacturing facility.SOLUTION: In a method for manufacturing a round steel pipe 99 from a steel plate 90, a one-side first face 90a out of faces which are formed by partitioning a face for forming an inner wall of the round steel pipe 99 at the steel plate 90 into three zones is bent by press-molding, the other side second face 90b out of faces which are formed by partitioning the face for forming the inner wall of the round steel pipe 99 at the steel plate 90 into three zones is bent by press-molding, a third face 90c out of faces which are formed by partitioning the face for forming the inner wall of the round steel pipe 99 at the steel plate 90 into three zones is bent by press-molding, a semi-molded round steel pipe 96 is manufactured by welding a side edge of the steel plate 90 at the first face 90a side, and a side edge of the steel plate 90 at the second face 90b side while being abutted on each other, and the semi-molded round steel pipe 96 is molded to the round steel pipe 99 by pressurizing an inner wall of the manufactured semi-molded round steel pipe 96. There is also provided a round steel pipe manufacturing facility 10 for the method.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a round steel pipe from a steel plate and a round steel pipe manufacturing facility for manufacturing a round steel pipe by the method.

  Conventionally, as a method of manufacturing a round steel pipe from a steel plate, there is a manufacturing method as shown in Patent Documents 1 and 2. Patent Document 1 discloses a method for manufacturing a round steel pipe, in which a plate is bent into a U-shape by a U-press, then formed into a tubular shape by an O-press equipped with a stepwise press tool, and a welded portion is seam-welded and then expanded. This is a method of expanding the pipe.

  Further, the method for manufacturing a round steel pipe disclosed in Patent Document 2 is to press a steel plate having a predetermined width with grooves formed at both ends in the width direction by press-forming a plurality of intermediate portions in the width direction to form a steel plate having both ends in the width direction. In the specific portion, a straight portion of a desired length remains, and each of the straight portions is bent and formed as an arc portion, and the bent formed body is welded and joined in a state where the groove portions thereof are in considerable contact. A method of forming a semi-formed round steel pipe, heating the whole of the semi-formed round steel pipe, and then passing the forming surface between a plurality of forming rolls having a semi-circular shape corresponding to the final radius to perform hot forming. is there.

JP-A-2002-102931 JP 2005-324255 A

  However, in the method for manufacturing a round steel pipe disclosed in Patent Document 1, in order to appropriately seam-weld a portion to be joined, an end bending press (a bending process) in which both side edges of the plate are bent before the plate is bent by a U press. ), It is necessary to make the portion to be joined flat. Therefore, there is a problem that the manufacturing process becomes complicated. In addition, in the method for manufacturing a round steel pipe disclosed in Patent Document 1, since the U press and the O press are performed using separate molds, there is a problem that the equipment configuration is complicated and the manufacturing process is complicated.

  Further, in the method for manufacturing a round steel pipe disclosed in Patent Document 2, in order to form the straight portion remaining in the semi-formed round steel pipe into an arc shape, the entire semi-formed round steel pipe is heated. When a round steel pipe is formed from a steel pipe, a step of heating the entire semi-formed round steel pipe is required. Therefore, there is a problem that the manufacturing process becomes complicated.

  Further, in a conventional method for manufacturing a round steel pipe, a semi-formed round steel pipe as a collection of a large number of small diameter round sections is formed by pressing a large number of places of a steel sheet several tens of times or more with a press forming machine (bending device). Since the pipe is formed and further refined by hand to make the cross-sectional shape of the formed semi-formed round steel pipe into a perfect circle, the above-mentioned press working and refinement work require time, and There was a problem that the process became complicated.

  Accordingly, an object of the present invention is to provide a method for manufacturing a round steel pipe and a facility for manufacturing a round steel pipe capable of manufacturing a round steel pipe from a steel plate by a simple manufacturing process with a simplified facility configuration.

  The problem to be solved by the present invention has been described above. Next, means for solving the problem will be described.

  That is, the method for manufacturing a round steel pipe according to the present invention is a method for manufacturing a round steel pipe from a steel sheet, wherein one of three surfaces of the steel sheet forming an inner wall of the round steel pipe is divided into three. The first surface is bent in an arc shape with the entire surface of the first surface on the side being formed by press molding, and the surface forming the inner wall of the round steel pipe is divided into three in the steel plate having the first surface bent. The second surface is bent in an arc shape with the entire surface of the second surface on the other side being formed by press forming, and the inner wall of the round steel pipe is formed from the steel plate in which the first surface and the second surface are bent. The entire surface of the third surface sandwiched between the first surface and the second surface among the surfaces into which the surface is divided into three is formed as a molding range of press molding, and the third surface is bent in an arc shape, and the third surface is bent. Abutting a side edge of the steel sheet on one side with a side edge of the steel sheet on the second side And pipe-making the semi-molded round steel pipe by welding is a method for molding the semi-molded round steel pipe to the round steel pipe by pressurizing the wall surface of the semi-molded round steel pipe which is pipe-making.

  In the method for manufacturing a round steel pipe according to the present invention, in the method for manufacturing a round steel pipe, the semi-formed round steel pipe is formed into the round steel pipe by pressing an inner wall of the formed semi-formed round steel pipe. Is the way.

  The round steel pipe manufacturing equipment of the present invention is a round steel pipe manufacturing equipment for manufacturing a round steel pipe from a steel sheet, and a bending device for bending a surface forming an inner wall of the round steel pipe in the steel sheet by press forming; A welding device for abutting and welding both side edges of the steel plate bent by the bending device; and a pressurizing device for pressing a wall surface of a semi-formed round steel pipe to be formed by welding by the welding device, wherein the bending is performed. The apparatus is configured to bend the first surface into an arc shape with the entire surface of the first surface on one side of the three surfaces of the steel plate forming the inner wall of the round steel pipe as a forming range of press forming. In the steel plate having the first surface bent, the entire surface of the second surface on the other side of the three surfaces forming the inner wall of the round steel pipe is defined as a forming range of the press forming, and the second surface is defined as the pressing range. Arc shape In the steel plate obtained by bending and bending the first surface and the second surface, the surface forming the inner wall of the round steel pipe is sandwiched between the first surface and the second surface of the three divided surfaces. The third surface is bent in an arc shape with the entire surface of the third surface being a forming range of the press forming.

  According to the method for manufacturing a round steel pipe and the round steel pipe manufacturing equipment of the present invention, when forming a semi-formed round steel pipe which is a stage before the round steel pipe, the vicinity of both side edges of the steel sheet is bent by press forming. Therefore, when the both side edges of the steel plate are butted and welded, the butted portion of the both side edges of the steel plate becomes flat. Therefore, it is not necessary to perform an end bending press (a bending process) before press-forming a steel plate, and the manufacturing process of manufacturing a round steel pipe from a steel plate can be simplified. Further, when forming a semi-formed round steel pipe, three predetermined portions of the steel plate can be bent by the same die. Therefore, a round steel pipe can be manufactured by a simple manufacturing process with a simplified facility configuration. Furthermore, since the straight portion does not remain in the formed semi-formed round steel pipe, it is not necessary to heat the entire semi-formed round steel pipe when forming the round steel pipe from the semi-formed round steel pipe. Therefore, a round steel pipe can be manufactured by a simple manufacturing process with a simplified facility configuration. Furthermore, since a round steel pipe is manufactured by bending predetermined three places of a steel plate, the number of press workings for forming a semi-formed round steel pipe can be reduced, and the three large diameter round sections are used. The cross-sectional shape of the tube can be formed into a round shape. Therefore, a round steel pipe can be manufactured by a simple manufacturing process.

It is explanatory drawing which shows the manufacturing process of the round steel pipe in the round steel pipe installation which concerns on this invention. It is explanatory drawing which shows the process of the press forming in the forming press of the round steel pipe installation which concerns on this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a round steel pipe manufacturing facility 10 according to the present invention is a facility for manufacturing a round steel pipe (round steel pipe 99) from a steel plate 90 having a thickness of 12 mm to 70 mm. The round steel pipe manufacturing equipment 10 forms a bent steel sheet 92 from the steel sheet 90, subsequently forms a semi-formed round steel pipe 96 from the bent steel sheet 92, and further forms a round steel pipe 99 from the semi-formed round steel pipe 96. I do.

  In the round steel pipe manufacturing facility 10, first, a steel plate 90 having a predetermined length is transported in the length direction N and is introduced into the groove processing machine 11. The groove processing machine 11 forms grooves 91 on both side edges in the width direction W of the steel plate 90.

  Next, the steel plate 90 is introduced into the forming press 12 (an example of a “bending device”). In the forming press 12, a first surface 90 a, a second surface 90 b, and a third surface 90 c, which are obtained by dividing a surface forming the inner wall of the round steel pipe 99 in the steel plate 90 into three in the width direction W of the steel plate 90, are sequentially arranged. Bend by press molding. Here, the first surface 90a of the steel plate 90 is one side (for example, the steel plate 90) of the three surfaces of the steel plate 90, which form the surface forming the inner wall of the round steel pipe 99 in the width direction W of the steel plate 90. On the right side in the width direction W), and a groove 91 is formed at one edge of the surface. The second surface 90b of the steel plate 90 is defined as the other side (the first surface 90a is one of three surfaces in which the surface forming the inner wall of the round steel pipe 99 in the steel plate 90 is divided into three in the width direction W of the steel plate 90). It refers to a surface on the opposite side to the formed side, for example, the left side in the width direction W of the steel plate 90), and a groove 91 is formed at one edge of the surface. Further, the third surface 90c of the steel plate 90 is defined as the first surface 90a and the second surface of the three surfaces of the steel plate 90 which form the inner wall of the round steel pipe 99 in the width direction W of the steel plate 90. 90b (a surface formed at the center in the width direction W of the steel plate 90). In the round steel pipe manufacturing facility 10, each of the three surfaces of the first surface 90 a, the second surface 90 b, and the third surface 90 c is a forming range of the press forming by the forming press 12. That is, in the round steel pipe manufacturing facility 10, the range in which the steel plate 90 is press-formed by the forming press 12 is divided into three predetermined ranges.

  The forming press 12 is an air-bend type pressing means, and includes a pair of lower molds 12A movable close to and away from each other in the left and right direction, and an upper mold 12B movable close to and away from the lower mold 12A in the vertical direction. , Consisting of The pair of lower molds 12A form an upward concave molding surface at a predetermined interval from each other. The distance between the pair of lower molds 12A is set according to the bending angle of the steel plate 90. The upper mold 12 </ b> B has an arc-shaped convex forming surface corresponding to a bending angle of the steel plate 90 at a tip portion thereof.

  In the forming press 12, the first surface 90a to the third surface 90c are press-formed by moving the upper die 12B up and down with respect to the lower die 12A on which the steel plate 90 is placed. That is, in the round steel pipe manufacturing facility 10, three predetermined surfaces (three places) of the steel plate 90 are bent by one common mold (the lower mold 12A and the upper mold 12B).

  Specifically, as shown in FIG. 2, first, the end of the steel plate 90 on the first surface 90a side is placed on the lower die 12A of the forming press 12. At this time, the back surfaces of the first surface 90a of the steel plate 90, that is, the back surfaces at both ends in the width direction W of the first surface 90a are mounted on the mounting surfaces 12a of the lower mold 12A. Then, the upper mold 12B is moved close to the entire first surface 90a of the steel plate 90 placed on the lower mold 12A. At this time, in the upper mold 12B, the tip position of the groove 91 (one side edge in the width direction W of the steel sheet 90) on the first surface 90a side of the steel sheet 90 is higher than the height of the mounting surface 12a of the lower mold 12A. The first surface 90a of the steel plate 90 is pushed down so as to be at a position lower by the predetermined height D. Accordingly, a straight portion does not remain at one end in the width direction W on the first surface 90a side of the steel plate 90, and the entire surface of the first surface 90a of the steel plate 90 is set as a forming range of the press forming. Can be bent in an arc shape. By the first press forming by the forming press 12, the first surface 90a side of the steel plate 90 is bent into an arc shape having a center angle of approximately 120 degrees.

  Subsequently, as shown in FIG. 1, the steel plate 90 having the first surface 90 a side bent in an arc shape is moved in the width direction W, and the lower die 12 </ b> A of the forming press 12 is moved to the end of the steel plate 90 on the second surface 90 b side. Place the part. At this time, the back surfaces of the second surface 90b of the steel plate 90, that is, the back surfaces at both ends in the width direction W of the second surface 90b are mounted on the mounting surfaces 12a of the lower mold 12A. Then, the upper mold 12B is moved close to the entire second surface 90b of the steel plate 90 placed on the lower mold 12A. At this time, in the upper mold 12B, the tip position of the groove 91 (the other side edge in the width direction W of the steel sheet 90) on the second surface 90b side of the steel sheet 90 is higher than the height of the mounting surface 12a of the lower mold 12A. The second surface 90b of the steel plate 90 is pushed down so as to be at a position lower by the predetermined height D. Accordingly, a straight portion does not remain at one end in the width direction W on the second surface 90b side of the steel plate 90, and the entire surface of the second surface 90b of the steel plate 90 is set as a forming range of the press forming, so that the second surface 90b is formed. Can be bent in an arc shape. As described above, the second press forming by the forming press 12 bends the second surface 90b side of the steel plate 90 into an arc shape having a center angle of approximately 120 degrees.

  Subsequently, the steel plate 90 having the first surface 90a and the second surface 90b bent in an arc shape is moved in the width direction W, and the central portion of the steel plate 90 forming the third surface 90c in the lower mold 12A of the forming press 12 is formed. Is placed. Then, the upper die 12B is moved close to the entire third surface 90c of the steel plate 90 placed on the lower die 12A. As a result, the third surface 90c is bent in an arc shape with the entire surface of the third surface 90c of the steel plate 90 set as a press forming range without leaving any straight portion on the third surface 90c of the steel plate 90. By the third press forming by the forming press 12 in this manner, the central portion (the third surface 90c) of the steel plate 90 is bent into an arc shape having a central angle of approximately 120 degrees, and the first surface 90a and the third surface of the steel plate 90 are bent. 90c forms a bent steel plate 92 bent in an arc shape.

  As described above, in the forming press 12, the surface on the side of the steel plate 90 on which the inner wall of the round steel pipe 99 is formed is divided into three, and each of the three divided surfaces (from the first surface 90a to the third surface). Is formed as a forming range of the press forming by three times of press forming one surface at a time from the surface side to form a bent steel plate 92. In other words, the bent steel plate 92 is formed by sequentially applying a force to three predetermined surfaces of the steel plate 90 forming the inner wall of the round steel pipe 99 into three sections from the side that becomes the inner wall of the round steel pipe 99.

  Further, in the forming press 12, the vicinity of both side edges (the first surface side and the second surface side) where the groove 91 is formed in the steel plate 90 is bent by press forming. When the both side edges of the steel plate 92) are butted and welded, the butted portions of the both side edges of the steel plate 90 become flat. Therefore, it is not necessary to perform an end bending press (a bending process) before press-forming the steel plate 90, and the manufacturing process of manufacturing the round steel pipe 99 can be simplified.

  Subsequently, the bent steel plate 92 bent by the forming press 12 is moved in the length direction N and introduced into the tack welding machine 14 (an example of a “welding device”). By pressing from the outside of the bent steel plate 92 (the side to be the outer wall of the round steel pipe 99) in the tack welding machine 14, the grooves 91 are butted to form a butted portion. Then, the tack welding machine 14 performs tack welding 95 on the butt portion. That is, the tack welding machine 14 performs the tack welding 95 on the bent steel plate 92 in a state where the both side edges of the bent steel plate 92 are butted. As described above, the tack welder 14 performs tack welding 95 on the bent steel plate 92, thereby forming a semi-formed round steel pipe 96. Here, the semi-formed round steel pipe 96 is a round steel pipe of a semi-formed product in an intermediate forming process of the manufacturing process of the round steel pipe 99, and has a round cross section of the pipe more than the round steel pipe 99 as the final product. It refers to a crude round steel pipe with an irregular shape.

  Further, the semi-formed round steel pipe 96 on which the tack welding 95 has been performed is introduced into the inner surface welding machine 21 (an example of a “welding device”). The inner surface welding machine 21 performs the inner surface welding 97 on the semi-formed round steel pipe 96. Furthermore, the semi-formed round steel pipe 96 is introduced into the outer surface welding machine 22 (an example of a “welding device”). The outer surface welding machine 22 performs outer surface welding 98 on the semi-formed round steel pipe 96.

  Next, the semi-formed round steel pipe 96 is introduced into the expander 15 (an example of a “pressing device”). The expander 15 mounts a tapered cone 18 via a jaw 17 in a cylindrical die 16 formed by arranging a large number of die segments 16A in the circumferential direction, and pulls the cone 18 with a draw bar 19 to form a die. This is a device for expanding the outer diameter of the tube by expanding the outer diameter of the tube. In the expander 15, the expansion head 20 is inserted from the end of the semi-formed round steel tube 96. By moving the cone 18 connected to the draw bar 19 in the axial direction or by moving the semi-formed round steel tube 96 in the axial direction, the jaw 17 is expanded by the wedge action of the cone 18 and the jaw 17. As a result, the die 16 attached to the outside of the jaw 17 abuts against the inner wall of the semi-formed round steel tube 96, and pressurizes the inner wall of the semi-formed round steel tube 96 so that the semi-formed round steel tube 96 is moved from inside to outside. Spread it out. Then, when the die 16 presses the inner wall of the semi-formed round steel tube 96 over the entire length of the semi-formed round steel tube 96, the entire length of the semi-formed round steel tube 96 is expanded. The expander 15 expands the semi-formed round steel tube 96 from the inside to the outside, thereby forming the semi-formed round steel tube 96 into a round shape in a side view. The expander 15 presses the inner wall of the semi-formed round steel pipe 96 with the die 16 so that the inner diameter of the semi-formed round steel pipe 96 is uniform over the entire circumference of the semi-formed round steel pipe 96. Thus, a round steel pipe 99 as a product is formed.

  As described above, according to the method for manufacturing the round steel pipe 99 and the round steel pipe manufacturing equipment 10 according to the present embodiment, when forming the semi-formed round steel pipe 96 which is a stage before the round steel pipe 99, Since the vicinity of both side edges of the steel plate 90 is bent by press forming, when the both side edges of the steel plate 90 (bent steel plate 92) are butted and welded, the butted portions of the both side edges of the steel plate 90 become flat. Therefore, it is not necessary to perform an end bending press (a bending process) before press-forming the steel plate 90, and the manufacturing process of manufacturing the round steel pipe 99 from the steel plate 90 can be simplified. Further, at the time of forming the semi-formed round steel tube 96, three predetermined portions of the steel plate 90 can be bent by the same die (the lower die 12A and the upper die 12B). Therefore, the round steel pipe 99 can be manufactured by a simple manufacturing process with a simplified facility configuration. Further, since the straight portion does not remain in the formed semi-formed round steel tube 96, it is not necessary to heat the entire semi-formed round steel tube 96 when forming the round steel tube 99 from the semi-formed round steel tube 96. . Therefore, the round steel pipe 99 can be manufactured by a simple manufacturing process with a simplified facility configuration. Furthermore, since the round steel pipe 99 is manufactured by bending predetermined three places of the steel plate 90, the number of press workings for forming the semi-formed round steel pipe 96 can be reduced, and the three large diameter steel pipes 96 can be reduced. The round section allows the cross-sectional shape of the tube to be formed into a round shape. Therefore, the round steel pipe 99 can be manufactured by a simple manufacturing process.

  In the present embodiment, an air bending type molding press 12 is shown as an example of a bending device. However, the present invention is not limited to this, and the lower mold 12A may be integrally formed with a concave molding surface facing upward. And a press-cut type bending device that moves the upper die closer to the die.

  Further, in the present embodiment, the round steel pipe 99 is formed by pressing and expanding the semi-formed round steel pipe 96 from the inside to the outside by the die 16 of the expander 15, but the method is not limited to this method. However, if the inner wall of the semi-formed round steel pipe 96 is pressurized to expand the semi-formed round steel pipe 96 from the inside to the outside, for example, a hydraulic expansion machine (water inside the semi-formed round steel pipe 96 may be used). And applying pressure).

  Further, in the present embodiment, the round steel pipe 99 is formed by expanding the semi-formed round steel pipe 96 from the inside to the outside by the expander 15, but the present invention is not limited to this method. As long as the molded round steel pipe 96 can be formed into a perfect round steel pipe 99, the round steel pipe 99 may be formed by compressing the outer wall of the semi-formed round steel pipe 96 from outside to inside. . In this case, the round steel pipe 99 is formed by a press-type press device in which the lower mold and the upper mold are fitted and pressed from the outer wall side of the semi-formed round steel pipe 96. In addition, the round steel pipe 99 is formed by a roll-type pressing device that presses the outer wall side of the semi-formed round steel pipe 96 with a plurality of rolls.

10 Round steel pipe manufacturing equipment 12 Forming press (bending device)
14 Temporary welding machine (welding equipment)
15 Expander (pressurizing device)
21 Inner surface welding machine (welding equipment)
22 External surface welding machine (welding equipment)
90 Steel plate 90a First surface 90b Second surface 90c Third surface 96 Semi-formed round steel pipe 99 Round steel pipe

Claims (3)

A method of manufacturing a round steel pipe from a steel plate,
In the steel plate, the entire surface of the first surface on one side of the three-part surface forming the inner wall of the round steel pipe is bent into an arc shape as a forming range of press forming,
In the steel plate having the first surface bent, the surface forming the inner wall of the round steel pipe is divided into three surfaces. Bent in an arc,
A third steel plate sandwiched between the first surface and the second surface of the steel plate obtained by bending the first surface and the second surface, the surface forming the inner wall of the round steel pipe being divided into three. The third surface is bent in an arc shape with the entire surface of the surface being a molding range of press molding,
A semi-formed round steel pipe is formed by abutting and welding a side edge of the steel sheet on the first surface side and a side edge of the steel sheet on the second surface side,
A method for manufacturing a round steel pipe, wherein the semi-formed round steel pipe is formed into the round steel pipe by pressing a wall surface of the formed semi-formed round steel pipe. The method for producing a round steel pipe according to claim 1, wherein the semi-formed round steel pipe is formed into the round steel pipe by pressurizing an inner wall of the formed semi-formed round steel pipe. A round steel pipe manufacturing facility for manufacturing a round steel pipe from a steel sheet,
A bending device that bends the surface forming the inner wall of the round steel pipe by press molding in the steel plate,
A welding device that welds by butt welding both side edges of the steel plate bent by the bending device,
A pressurizing device that presses the wall surface of the semi-formed round steel pipe that is welded and formed by the welding device,
With
The folding device,
In the steel plate, the entire surface of the first surface on one side of the three-part surface forming the inner wall of the round steel pipe is bent into an arc shape as a forming range of press forming,
In the steel plate having the first surface bent, the surface forming the inner wall of the round steel pipe is divided into three surfaces. Bent in an arc,
A third steel plate sandwiched between the first surface and the second surface of the steel plate obtained by bending the first surface and the second surface, the surface forming the inner wall of the round steel pipe being divided into three. A round steel pipe manufacturing facility, characterized in that the third surface is bent in an arc shape with the entire surface of the surface being a forming range of press forming.

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