WO2016104718A1

WO2016104718A1 - Pipe forming method and device

Info

Publication number: WO2016104718A1
Application number: PCT/JP2015/086261
Authority: WO
Inventors: 王　飛舟; 紀龍尹; 中野　智康; 孝充三浦
Original assignee: 株式会社中田製作所
Priority date: 2014-12-26
Filing date: 2015-12-25
Publication date: 2016-06-30

Abstract

The purpose of the present invention is to manufacture a round pipe the diameter of which is from a few inches to tens of inches, using a small number of stages (number of steps, number of stands), and while suppressing irregular deformation such as sagging at the leading end or tail end of a material, which is a problem that occurs if a sheet material is used as the molding material. In order to achieve the foregoing, in the present invention, a BD stand (10) is formed by a pair of rotation units (11, 11). An FP stand (20), which is provided at a stage subsequent to the BD stand (10) stage, has a one-stand three-roll configuration in which a rotation unit (21) is used as an upper unit and molding rolls (22, 23) are used as a side unit and a lower unit. The pair of rotation units (11, 11) in the BD stand (10) and the rotation unit (21) in the FP stand (20) overlap at the side where the units are adjacent. In that overlap area, while an open pipe is held by an auxiliary bottom roll (32) which is liftable, portions of the open pipe near both edges thereof are subjected to a pressing force by side support rolls (31, 31) which are present on both sides of the open pipe.

Description

Tube forming method and apparatus

The present invention relates to a method and apparatus for forming a tube used for manufacturing a round tube or the like from a metal material coil or a sheet metal material having a required length, and a tube welding method and apparatus.

One of the tube forming methods is called ODF. One of them is a forming method using a giant forming arc in which a giant forming roll is virtually imagined by an endless die array, and is described in Patent Document 1.

This molding method supports a hole die array in which a hole die provided with a molding hole mold facing outward is connected to an endless line so as to be able to turn on an endless track, and in a part of the hole mold in the turning direction, A swivel unit provided with an arc of a huge radius assuming a huge forming roll is used, and an effect equivalent to the forming by the huge forming roll can be obtained by a small forming stand.

Normally, application of this swivel unit to an upper unit, a lower unit, and side units on both sides, for example, as a sizing stand or a fin pass stand is considered.

Another ODF is a forming method that bends a plate material from a flat plate to an open pipe by restraining both edge portions of the plate material between a pair of endless die rows and moving the die. ing.

In this molding method, a pair of swivel units that support a swivel die row in which a swivel die having a forming hole mold facing outwardly and swivelly connected to an endless row is supported on an endless track. It is placed opposite to form a straight section where the interval gradually decreases, and the molding holes on both sides constrain both edges of the molding material while supporting the molding material entering the molding section with the bottom roll group. Thus, the molding material on both sides changes the swing angle, and the molding material is continuously bent into an open pipe.

By using this molding stand as a breakdown stand (BD stand) and arranging two to three fin pass roll stands and a squeeze roll stand on the downstream side, a relatively small number of steps (number of steps, stand) A high-quality welded pipe can be easily manufactured. In addition, even when a sheet material is used as the forming material, unsteady deformation such as sagging is rarely caused at the material front end portion and the material tail end portion.

However, it is difficult to manufacture a round tube having a diameter of several inches to several tens of inches.

In other words, when a sheet material is used as a molding material, the caliber is reduced with a small number of steps (number of steps, number of stands) while suppressing unsteady deformation such as sagging at the front end and tail end of the material, which is a particular problem. A pipe forming method that can produce round tubes of several inches to several tens of inches has not been proposed yet.

Incidentally, when the diameter of the welded pipe to be manufactured increases, the T / D becomes relatively small, so that the formability deteriorates and the width of the forming material increases, so that the material changes from the coil material to the sheet material. Because of the shift, manufacturing of a welded pipe having a large diameter inevitably requires processing with poor formability using a sheet material.

Japanese Patent No. 5057467 Japanese Patent No. 5523579

The object of the present invention is to reduce the number of steps (number of steps, number of stands) while suppressing unsteady deformation such as sagging at the leading end and tail end of the material, which is particularly problematic when a sheet material is used as a molding material. Thus, it is an object of the present invention to provide a method and apparatus for forming a pipe and a method and apparatus for welding a pipe that can manufacture a round pipe having a diameter of several inches to several tens of inches.

In order to achieve the above object, the inventors of the present invention have a pair of swiveling units, each having a swiveling die row connected to an endless row, swung on an endless track, as a BD stand, and a fin path on the downstream side. Focusing on the method of forming a tube by arranging a roll stand and a squeeze roll stand in series, in order to further improve the formability, instead of a fin pass roll stand, a hole in which a hole die is connected in an endless row We examined the placement of a four-turn unit fin pass stand (FP stand) in which the upper and lower units and the side units on both sides were used as the upper and lower units, and the rotary unit for rotating the die row on an endless track.

As a result, the moldability is improved and the process from the breakdown start to the end of the fin pass can be completed in two steps. However, the equipment cost increases due to the four-turn unit of the FP stand, the tool change time becomes long, and foreign matter It turned out that the problem of mixing arises.

Therefore, the present inventors examined that the turning unit was applied only to the upper unit of the FP stand, and that the lower unit and the side units on both sides were substituted with rolls. As a result, it has been found that the problem of equipment cost, tool replacement time, and foreign matter contamination can be solved while maintaining high formability.

In addition, since the phase around the pass line of the swivel unit is shifted between the BD stand and the FP stand (that is, the swivel unit in the FP stand is positioned between the pair of swivel units in the BD stand), Since they can be arranged close to each other and can be overlapped, it has been found that the material can be continuously constrained from the start of breakdown to the end of the fin path, and the formability can be greatly improved.

That is, in the BD stand, a pair of swivel units are arranged in a V shape as left and right units on both sides of the pass center, and in the FP stand, one swivel unit is vertically arranged on the pass center as an upper unit. Even if the swivel units are arranged close to each other, mutual interference is avoided, and an arcuate swivel return part on the upstream side of the swivel unit in the FP stand is between the arcuate swivel return parts on the downstream side of the pair of swivel units in the BD stand. It is also possible to insert and arrange the spring back, so that the spring back between the stands can be suppressed very small.

In particular, when the forming material is a sheet material, roll forming itself is difficult because the material tip and the material tail end are poorly formed, but in this method, from the material tip to the material tail end. Therefore, it is possible to form not only the coil material but also a sheet material with particularly bad formability at both ends, with good yield.

Also, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other in series, and the swivel return portions of both swivel units are preferably overlapped on the close side, and then the BD stand is exited. Effectiveness of disposing side support rolls that can press open pipes from both sides in the vicinity of the swivel unit, effectiveness of disposing the bottom roll group in the BD stand to the vicinity of the swivel unit, and lower roll in the FP stand The effectiveness of adjusting the pass line height of the auxiliary bottom roll by arranging the auxiliary bottom roll so that it can be moved up and down in the vicinity of the lower roll is revealed.

In addition, when the BD stand using the swivel unit and the FP stand are arranged in series, or when the FP stand is arranged close to the next stage of the breakdown roll stand group, the material retention in the FP stand is good. Just arrange a sizing roll stand (SZ stand) consisting of two upper and lower two rolls or four upper, lower, left and right rolls on the downstream side (ie, only the combination of the FP stand and the downstream SZ stand) and inline As a result, it has been found that a welded tube can be manufactured with a small number of steps (number of steps, number of stands) as a whole.

It has been found that in-line outer surface welding is possible with a tack weld stand (TW stand) arranged at the next stage of the SZ stand or a squeeze roll stand (SQ stand) arranged between the FP stand and the SZ stand.

Specifically, the TW stand is a roller beam stand in which a large number of small-diameter rollers arranged in parallel along the length of the raw tube are arranged at a plurality of locations in the circumferential direction of the open pipe. By arranging a welding machine such as a TIG welding machine in the part, both edge parts of the open pipe are continuously welded from the outer surface side. In addition, the TW stand is a TW stand in which the roller beam arranged at the top is shortened and a space for arranging the welding machine is secured on the downstream side. In addition, the TW stand is a TW stand in which a roller beam disposed at a lower portion is replaced with a bottom roll group including a plurality of concave rolls.

When performing in-line outer surface welding, in the FP stand, a fin is provided at the center of the inner surface of each perforated die constituting the swivel unit in order to position the open pipe in the circumferential direction and to prevent overlapping of both edge portions. It turned out to be effective. When in-line outer surface welding is performed with a TW stand arranged at the next stage of the SZ stand, it is effective to provide a fin at the center of the inner surface of the upper roll in the SZ stand together with each hole die of the swivel unit in the FP stand. It has been found.

Regarding in-line outer surface welding, from the viewpoint of improving the quality of outer surface welding, a pair of upper and lower inner surfaces that support the upper inner surface and lower inner surface of the raw pipe (open pipe) at the throttle position of the SZ stand, respectively. It has been found that it is effective to arrange the rollers using a mandrel arranged in an open pipe. That is, the arrangement of the pair of upper and lower inner surface support rollers at the throttle position of the SZ stand makes the contact state of the end surfaces of both edge portions where the raw pipe (open pipe) is to be welded extremely good, and subsequently is performed on the TW stand. The quality of the in-line outer surface welding is kept constant and good.

Further, in the FP stand, a pair of upper and lower inner surface support rollers for abutting and supporting the upper inner surface and the lower inner surface of the raw pipe (open pipe) are used by using a mandrel disposed in the raw pipe (open pipe). A squeeze function at the squeezing position is provided by disposing an upper surface supporting roller with fins that abuts and supports the upper inner surface of the raw pipe (open pipe) on the upstream side using the mandrel. In addition, the anti-rolling function by fins on the upstream side is synergistic, and the abutting position of both edge end surfaces to be welded is held as specified, so that the outer surface welding quality is further improved, and the SZ stand's aperture is further reduced. It has been found that by synergistic with the arrangement of a pair of upper and lower inner surface support rollers at the position, the outer surface welding quality is further improved.

In-line inner surface temporary welding is performed by an inner surface welding torch arranged at the drawing position in the FP stand using a mandrel arranged in an open pipe (open pipe). In this case, the FP stand is a squeeze type in which fins are removed from each hole die of the swivel unit and a squeeze function (a function of bringing both edges into close contact) is given to the FP stand.

For the squeeze type FP stand without fins used for in-line inner surface temporary welding, an inner surface welding torch is disposed at the throttle position of the FP stand by a mandrel, and the upper inner surface and lower inner surface of the raw pipe (open pipe) are in contact with each other. A pair of upper and lower inner surface supporting rollers to be supported are arranged so as not to interfere with the inner surface welding torch using the mandrel, and preferably, fins for abutting and supporting the upper inner surface of the raw pipe (open pipe) on the upstream side thereof By arranging the upper support roller with the above mandrel, the squeeze function at the throttle position and the rolling prevention function by the fin on the upstream side are synergistically specified, and the butt position of both edge end surfaces to be welded is specified It was found that the internal temporary welding quality was further improved by being held as it was.

The tube forming method and apparatus of the present invention have been developed based on this knowledge,
A pair of swivel units, which support a swivel die row in which endless swivel dies, each having a forming hole mold facing outwardly and swingably connected, can be swung on an endless track, are linearly spaced between them. Oppositely arranged so as to form a gradually decreasing molding section, while supporting the molding material entering the molding section with the bottom roll group, both edge portions of the molding material are constrained by the molding hole molds on both sides and moved synchronously. A BD stand that continuously bends the molding material into an open pipe by changing the swing angle of the mold hole molds on both sides,
A die array, in which a hole die with the mold hole facing outward, is connected to an endless row so as to be able to swivel on an endless track, and a radius that assumes a giant forming roll in a part of the hole shape in the swivel direction The swivel unit with a circular arc is used for the upper unit, and the lower unit and the FP stand using the rolls for the side unit are arranged in series,
The pair of swivel units in the BD stand and the swivel unit in the FP stand are arranged close to each other, and preferably the pair of swivel units in the BD stand and the swivel unit in the FP stand overlap on the close side. A tube is formed by inserting and arranging a swivel return portion on the upstream side of the swivel unit in the FP stand between the swivel return portions on the downstream side of the pair of swivel units.

Such a tube forming method and apparatus are shown in FIG. 1, FIG. 2, or FIG. In the figure, 10 is a BD stand, 11 and 11 are a pair of turning units in the BD stand 10, 12 is a bottom roll group in the BD stand 10, 20 is an FP stand, 21 is a turning unit in the FP stand 20, 22 is A side unit roll in the FP stand 20, a lower unit roll in the FP stand 20, and an overlap portion 30 between the pair of turning

units

11 and 11 in the BD stand 10 and the turning unit 21 in the FP stand 20. 1 and 2 or 3, the pair of turning

units

11 and 11 in the BD stand 10 and the turning unit 21 in the FP stand 20 are close to each other. In FIGS. 1 and 2, an overlap portion 30 is particularly formed. ing.

That is, the pipe forming method and apparatus according to the present invention is a small-sized and easy-to-resize BD stand using a pair of swiveling units, and completes the formation of a flat plate to an open pipe in one step. The opened open pipe is sent to the FP stand without springback, and the FP stand performs efficient fin pass molding with a single stand configuration that uses a swivel unit only for the upper unit and can be easily resized. is there.

The tube forming method and apparatus of the present invention also has a pair of swivel units in the BD stand and a swivel unit in the FP stand arranged close to each other, preferably with both swivel units overlapped before exiting the BD stand. A pair of one or more side support rolls for pressing the open pipe from both sides is arranged in the vicinity of the swivel unit, preferably the overlap portion, to form the pipe.

Such a tube forming method and apparatus are shown in FIGS. 4A and 4B. Here, the side support roll 31 is a concave roll capable of pressing the vicinity of the edge of the open pipe, but a cage roll using a flat roll can also be used. The pair of turning

units

11 and 11 in the BD stand 10 and the turning unit 21 in the FP stand 20 are close to each other, and in particular, an overlap portion 30 is formed in FIG. 4A. Moreover, in FIG. 4B, since the turning

units

11 and 11 and the turning unit 21 are separated from each other as compared with FIG. 4A, many side support rolls 31 are arranged along the line.

The tube forming method and apparatus according to the present invention also includes a pair of swiveling units in the BD stand and a swiveling unit in the FP stand that are arranged close to each other, preferably after both swiveling units are overlapped, and a bottom roll in the BD stand. The tube is formed by extending the group to the vicinity of the swivel unit, preferably the overlapping portion.

Such a pipe forming method and apparatus are shown in FIG. 5, and 32 is a bottom roll in which the overlap portion 30 is extended.

The tube forming method and apparatus of the present invention also has a pair of swivel units in the BD stand and a swivel unit in the FP stand arranged close to each other, preferably with both swivel units overlapped before exiting the BD stand. One or more side support rolls capable of pressing the open pipe from both sides are arranged in the proximity part of the swivel unit, preferably the overlap part, and the bottom roll group in the BD stand is arranged in the proximity part of the swivel unit, preferably the overlap. The tube is formed by extending to the part.

Such a tube forming method and apparatus are shown in FIGS. 6A and 6B. Here, the side support roll 31 is a concave roll capable of pressing the vicinity of the edge of the open pipe, but a cage roll using a flat roll can also be used. The pair of

swivel units

11 and 11 in the BD stand 10 and the swivel unit 21 in the FP stand 20 are close to each other, and particularly, an overlap portion 30 is formed in FIG. 6A. Moreover, in FIG. 6B, since the turning

units

11 and 11 and the turning unit 21 are separated from each other as compared with FIG. 6A, many side support rolls 31 are arranged along the line.

In the pipe forming method and apparatus of the present invention, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, and preferably, both swivel units are overlapped, and then the lower unit in the FP stand. An auxiliary bottom roll is arranged on the upstream side of the roll so as to be close to the lower unit roll so that it can be moved up and down, and a pipe is formed by adjusting the pass line height of the auxiliary bottom roll.

Such a tube forming method and apparatus are shown in FIG. 7, and 24 is an auxiliary bottom roll. The bottom roll 32 extended to the overlap portion 30 can also serve as the auxiliary bottom roll 24.

In the pipe forming method and apparatus of the present invention, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, and preferably the both roll units are overlapped, and then the lower roll in the FP stand. An auxiliary bottom roll is arranged on the upstream side of the FP stand so that it can be moved up and down, and an SZ stand comprising two upper and lower two rolls or four upper, lower, left and right rolls is arranged on the next stage of the FP stand. The tube is formed by adjusting the drawing amount, the drawing amount in the SZ stand, and the pass line height of the auxiliary bottom roll.

FIG. 8 shows such a tube forming method and apparatus. 40 is an SZ stand disposed at the next stage of the FP stand 20, 41 is an upper and lower two-way roll, and 42 is a left and right two-way roll.
The bottom roll 32 extended to the overlap portion 30 also serves as the auxiliary bottom roll 24.

In the pipe forming method and apparatus of the present invention, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, and preferably the swivel units in the FP stand are overlapped with each other. A tube is formed by providing a fin in the center of the inner surface of each hole die.

In the pipe forming method and apparatus of the present invention, the fins are omitted or, instead of the fins, a concave relief portion is provided at the center of the inner surface of each hole die, and squeezing of the open pipe is performed in the FP stand. Is what you do.

The pipe welding method and apparatus according to the present invention further includes an FP stand following a line for forming a molding material on an open pipe by BD, an SZ stand on the downstream side, and both edges of the open pipe. Welding means for welding the outer surface or the inner surface temporarily is arranged in the line, and both edge portions of the open pipe are subjected to in-line outer surface welding or in-line inner surface temporary welding.

The pipe welding method and apparatus of the present invention is also provided with an SZ stand, preferably an upper roll, as a fin on the next stage of the FP stand, preferably an FP stand provided with a fin at the center of the inner surface of each hole die in the swivel unit. An SZ stand as a roll is disposed, and a TW stand that welds both edges of the open pipe as the welding means is restrained from the outer surface side as the welding means. Both edge portions are welded in-line.

The TW stand here is, for example, a roller beam stand in which a plurality of small-diameter rollers arranged in parallel along the longitudinal direction of the raw tube are arranged at a plurality of locations in the circumferential direction of the open pipe. By arranging a welding machine such as a TIG welding machine, both edge portions of the open pipe are continuously welded from the outer surface side. When the roller beam is disposed on the top of the open pipe, the roller beam is shortened to secure a space for arranging the welding machine.

The pipe welding method and apparatus of the present invention is also provided with an SZ stand, preferably an upper roll, as a fin on the next stage of the FP stand, preferably an FP stand provided with a fin at the center of the inner surface of each hole die in the swivel unit. An SZ stand as a roll is arranged, and a TW stand is arranged at the next stage, and the upper and lower inner surfaces of the open pipe are brought into contact with and supported from the open pipe at the throttle position of the SZ stand. A pair of inner surface support rollers are arranged using a mandrel, and both edge portions of the open pipe are welded in-line to the outer surface.

The pipe welding method and apparatus of the present invention is also provided with an SZ stand, preferably an upper roll, as a fin on the next stage of the FP stand, preferably an FP stand provided with a fin at the center of the inner surface of each hole die in the swivel unit. An SZ stand as a roll is arranged, and a TW stand is arranged at the next stage, and the upper and lower inner surfaces of the open pipe are contacted and supported from the open pipe at the throttle position of the FP stand. A pair of inner surface support rollers are disposed using a mandrel, and preferably, further on the upstream side, a finned inner surface support roller that abuts and supports the upper inner surface of the open pipe is disposed using the mandrel. Both edge portions are welded in-line.

The pipe welding method and apparatus of the present invention is also provided with an SZ stand, preferably an upper roll, as a fin on the next stage of the FP stand, preferably an FP stand provided with a fin at the center of the inner surface of each hole die in the swivel unit. An SZ stand as a roll is arranged, and a TW stand is arranged at the next stage, and the upper and lower inner surfaces of the open pipe are brought into contact with and supported from the open pipe at the throttle position of the SZ stand. A pair of inner surface support rollers are arranged using a mandrel, and a pair of upper and lower inner surface support rollers for abutting and supporting the upper inner surface and the lower inner surface of the open pipe from the inside of the open pipe at the throttle position of the FP stand, respectively. It is arranged with a mandrel, and preferably with a fin that abuts and supports the upper inner surface of the open pipe on the further upstream side. The inner surface support rollers disposed with a mandrel, is to line the outer surface welding both edges of the open pipe.

The pipe welding method and apparatus according to the present invention also includes an FP stand, particularly a finless squeeze FP stand in which fins are removed from the hole die in the swivel unit, following a line for forming a forming material into an open pipe by BD. At the same time, an SZ stand is arranged on the downstream side of the squeeze type FP stand, and a welding torch is arranged using a mandrel arranged in the open pipe so that both edges of the open pipe are temporarily connected to the inline inner surface. Welding.

In the pipe welding method and apparatus according to the present invention, the welding torch is disposed at the throttle position of the squeeze type FP stand using a mandrel disposed in the open pipe, and the upper inner surface and the lower inner surface of the open pipe. A pair of upper and lower inner surface support rollers for abutting and supporting each from the inside of the open pipe are arranged by the mandrel so that at least the upper inner surface support roller is shifted to the upstream side of the throttle position of the FP stand. An inner surface support roller with fins for abutting and supporting the upper inner surface of the open pipe is arranged further upstream of the inner surface support roller for the inner surface using the mandrel, and both edges of the open pipe are temporarily welded in-line on the inner surface. It is.

In the tube forming method and apparatus of the present invention, a BD stand is constituted by a pair of swivel units that support an endless rocking die row so as to be turnable on an endless track, and an endless hole die row is provided downstream thereof. The upper unit is a swivel unit supported so as to be able to swivel on an endless track, and an FP stand using rolls is placed on the lower unit and side unit, and a pair of swivel units in the BD stand and a swivel unit in the FP stand are close to each other. By arranging and preferably making both swivel units overlap, it is possible to efficiently form from the start of breakdown to the end of the fin pass in two steps. In addition, by adopting a swivel unit for the BD stand and the FP stand, the formability is essentially excellent, and a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, preferably both swivels By overlapping the units, the spring back of the open pipe between the two stands is suppressed, so that when the sheet material is used as the molding material, the sagging at the material tip and material tail end is particularly problematic. Thus, unsteady deformation such as the above can be suppressed, the sheet material can be formed, and material loss due to deformation of both end portions can be reduced.

The tube forming method and apparatus according to the present invention also includes a pair of swiveling units in the BD stand and a swiveling unit in the FP stand that are arranged close to each other, preferably after both swiveling units are overlapped, and a bottom roll in the BD stand. By extending the group to the adjacent part of the swivel unit, preferably the overlap part, it is possible to more effectively suppress the spring back of the open pipe between the two stands. Deformation that becomes a problem when a sheet material is used, and material loss due to this, can be further reduced.

The tube forming method and apparatus of the present invention also has a pair of swivel units in the BD stand and a swivel unit in the FP stand arranged close to each other, preferably with both swivel units overlapped before exiting the BD stand. One or more side support rolls that can press the vicinity of the edge of the open pipe are disposed in the vicinity of the swivel unit, preferably the overlap part, and the bottom roll group in the BD stand is disposed in the vicinity of the swivel unit, preferably By extending to the overlap part, the spring back of the open pipe between both stands can be more effectively suppressed, so it is excellent in formability, especially deformation that becomes a problem when using sheet material as a molding material, And the material loss by this can be reduced further.

In the pipe forming method and apparatus of the present invention, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, and preferably the both roll units are overlapped, and then the lower roll in the FP stand. The auxiliary bottom roll can be moved up and down in close proximity to the lower roll, and the pass line height of the auxiliary bottom roll can be adjusted. Since the warpage can be effectively corrected, the moldability is excellent.

In the pipe forming method and apparatus of the present invention, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, and preferably the both roll units are overlapped, and then the lower roll in the FP stand. An auxiliary bottom roll is arranged on the upstream side of the FP stand so that it can be moved up and down, and an SZ stand comprising two upper and lower two rolls or four upper, lower, left and right rolls is arranged on the next stage of the FP stand. By making it possible to adjust the drawing amount, the drawing amount in the SZ stand, and the pass line height of the auxiliary bottom roll, a round tube having a diameter of several inches to several tens of inches can be manufactured efficiently and with good moldability.

In the pipe forming method and apparatus of the present invention, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, and preferably the swivel units in the FP stand are overlapped with each other. By providing a fin at the center of the inner surface of each hole die, the moldability of the FP stand can be further improved.

In the pipe forming method and apparatus of the present invention, a pair of swivel units in the BD stand and a swivel unit in the FP stand are arranged close to each other, and preferably the two swivel units are overlapped, and the fins are omitted. Alternatively, instead of fins, a concave relief part for inner surface tack welding is provided at the center of the inner surface of each hole die, and the inner surface of the FP stand is subjected to inner surface tack welding of an open pipe, so that a thin material can be formed. The limit can be expanded.

That is, in the method and apparatus for forming a tube of the present invention, no buckling occurs on the FP stand exit side, so no wrapping occurs on the sizing stand. For this reason, a large aperture can be added by a sizing stand, and essentially high roundness can be obtained. Still, molding is not easy for thin-walled materials, but the inner surface of the FP stand is tacked on the inner surface of the open pipe so that molding is easy even for thin-walled materials. The effect is great. The auxiliary bottom roll can adjust the straightness of the open pipe by moving up and down.

The pipe welding method and apparatus according to the present invention further includes an FP stand following a line for forming a molding material on an open pipe by BD, an SZ stand on the downstream side, and both edges of the open pipe. By placing welding means to weld the outer surface or the inner surface temporary weld in the line and both edges of the open pipe are in-line outer surface welding or in-line inner surface temporary welding, high number of steps (number of steps, number of stands) Enables production of quality welded pipes.

In the pipe welding method and apparatus of the present invention, an SZ stand is arranged at the next stage of the FP stand, a TW stand is arranged at the next stage, and both edges of the open pipe are welded in-line on the outer surface, High quality welded pipes can be manufactured with a small number of steps (number of steps, number of stands).

In the pipe welding method of the present invention, an SZ stand is arranged at the next stage of the FP stand, and a TW stand is arranged at the next stage. By using a finned die in which fins are provided in the part, the outer surface welding quality can be further improved.

In the pipe welding method of the present invention, an SZ stand is arranged at the next stage of the FP stand, a TW stand is arranged at the next stage, and an upper roll of the SZ stand is used as a finned roll. Welding quality can be further improved.

In the pipe welding method and apparatus of the present invention, an SZ stand is arranged at the next stage of the FP stand, and a TW stand is arranged at the next stage. By disposing, the outer surface welding quality can be further improved.

In the pipe welding method and apparatus according to the present invention, an SZ stand is arranged at the next stage of the FP stand, and a TW stand is arranged at the next stage, and a pair of upper and lower inner surfaces are supported at the throttle position of the FP stand. By arranging the roller and the upper surface supporting roller with fins on the upstream side thereof, it is possible to improve the outer surface welding quality.

The pipe welding method and apparatus of the present invention can also reduce the number of steps (processes) by disposing the SQ stand between the FP stand and the downstream SZ stand and welding both edges of the open pipe in-line externally. High-quality welded pipes can be manufactured.

In the pipe welding method and apparatus according to the present invention, the FP stand is formed as a squeeze FP stand by removing the fins of the hole die in the swivel unit, and the inner surface welding torch is arranged at the throttle position of the squeeze FP stand. At the same time, by disposing the SZ stand on the downstream side of the squeeze type FP stand, both edge portions of the open pipe can be efficiently temporarily welded on the inner surface in-line.

In the pipe welding method and apparatus according to the present invention, the FP stand is formed as a squeeze FP stand by removing the fins of the hole die in the swivel unit, and the inner surface welding torch is arranged at the throttle position of the squeeze FP stand. In addition, an SZ stand is disposed on the downstream side of the squeeze type FP stand, and a pair of upper and lower inner surface support rollers are disposed in the FP stand, and at least the upper inner surface support roller is disposed upstream of the throttle position of the squeeze type FP stand. By disposing them, the inner surface temporary welding quality can be further improved.

In the pipe welding method and apparatus according to the present invention, the FP stand is formed as a squeeze FP stand by removing the fins of the hole die in the swivel unit, and the inner surface welding torch is arranged at the throttle position of the squeeze FP stand. In addition, an SZ stand is disposed on the downstream side of the squeeze type FP stand, and a pair of upper and lower inner surface support rollers are disposed in the FP stand, and at least the upper inner surface support roller is disposed upstream of the throttle position of the squeeze type FP stand. By disposing them and disposing the upper finned inner surface support roller further upstream of the upper inner surface support roller, the inner surface temporary welding quality can be further improved.

It is a top view of the shaping | molding apparatus of the pipe | tube which shows the structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows the same structure. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the shaping | molding apparatus of the pipe | tube which shows another structure of this invention. It is a side view of the BD stand and FP stand which are the principal parts of the shaping | molding apparatus which shows embodiment of this invention. It is a top view of the overlap part which is the principal part of the shaping | molding apparatus. It is a front view of the overlap part. It is a 3rd page figure of the turning unit of the FP stand which is the principal part of the shaping | molding apparatus, (a) is a top view, (b) is a side view, (c) is a front view. (A) with fins, (b) without fins (with concave relief for internal tack welding), (c) without fins (relief) None). It is a side view which shows the structure after the BD stand in the same shaping | molding apparatus. It is a side view of the pipe welding apparatus which shows another embodiment of this invention. FIG. 16 is a cross-sectional view taken along line AA in FIG. 15. It is a side view of the pipe welding apparatus which shows another embodiment of this invention. FIG. 18 is a cross-sectional view taken along line BB in FIG. It is CC sectional view taken on the line in FIG. FIG. 18 is a cross-sectional view taken along line DD in FIG. It is a side view of the pipe welding apparatus which shows another embodiment of this invention. FIG. 22 is a sectional view taken along line EE in FIG. 21. FIG. 22 is a sectional view taken along line FF in FIG. 21. FIG. 22 is a sectional view taken along line GG in FIG. 21. It is a side view of the pipe welding apparatus which shows another embodiment of this invention.

Embodiments of the present invention will be described below.

This embodiment is for manufacturing a welded pipe. As shown in FIGS. 9 to 11, the pipe making apparatus includes a forming apparatus including a BD stand 10 and an FP stand 20 arranged in series from the upstream side to the downstream side. Although not shown, upstream of the BD stand 10, an entry guide, an edge bend, and a roll bend for reverse bend are sequentially arranged toward the BD stand 10. On the other hand, on the downstream side of the FP stand 20, as shown in FIG. 14, an SZ stand 40 and a TW stand 50 are sequentially arranged from the upstream side to the downstream side. It constitutes a welding device.

The BD stand 10 includes a pair of

swivel units

11 and 11 that are arranged symmetrically opposite to each other across the path center, and a bottom roll group 12 that is disposed below the path center. The molding material is molded from a flat plate shape to an open pipe in cooperation with the bottom roll group 12 while passing between the pair of

swivel units

11 and 11. Hereinafter, the path center direction (tube axis direction) is referred to as the y direction, the horizontal direction (lateral width direction) perpendicular to the path center direction is referred to as the x direction, and the height direction is referred to as the z direction. Further, for convenience of illustration, the pair of turning

units

11 and 11 in the BD stand 10 is shortened to about １／ only in the y direction by omitting the central portion.

The individual swivel unit 11 is configured such that the endless die row 11a swivels along an oblong endless track that is long in the direction of the pass line (y direction). Specifically, the endless die row 11a is stretched between a pair of front and

rear sprocket units

11b and 11b arranged at intervals in the y direction, and one or both of the pair of front and

rear sprocket units

11b and 11b are By being rotationally driven, the endless die row 11a turns on an oblong endless track.

As shown in FIGS. 10 and 11, the

swivel units

11 and 11 on both sides are combined in a V shape when viewed from the front, and are used as a molding section through which the molding material passes between the linear track portions on the adjacent and opposing sides. At the same time, they are inclined in the x direction so that the distance between the linear tracks on both sides in the molding section gradually decreases from the upstream side toward the downstream side.

The endless die row 11a is configured by connecting a large number of forming dies 11c in a turning direction via a die holder 11d. Each of the molding dies 11c has a molding hole mold having an L-shaped cross section that engages with the edge portion of the molding material facing the outside of the swivel ellipse, and the die holder 11d changes the engagement angle with the edge portion of the molding material. It is supported in a swingable manner inside. And when each shaping | molding die 11c moves a shaping | molding area, a rocking | fluctuation angle is continuously changed with the movement, and the engagement angle with respect to an edge part is changed. Specifically, as the molding section moves from the upstream side to the downstream side, the molding hole mold having an L-shaped cross section is gradually directed downward.

In order to change the angle, a linear copying track is arranged along the forming section. On the side of the die holder 11d, the linear movement caused by the copying of the copying track by the die holder 11d is performed. A conversion mechanism such as a rack and pinion that converts to dynamic motion is attached.

The

swivel units

11 and 11 on both sides are installed on a movable gantry (not shown), and the distance between the linear tracks on both sides in the molding section is freely changed by the operation of the movable gantry.

Since the forming die 11c here is characterized by swinging, the forming die 11c is particularly referred to as a swinging die 11c, and the endless die row 11a connected thereto is particularly referred to as a swinging die row 11a.

The bottom roll group 12 includes a plurality of concave rolls 12a arranged in the y direction. The plurality of concave rolls 21 supports the molding material moving in the molding section from below, and changes the roll surface from an arc surface with a large radius to an arc surface with a small radius sequentially from the upstream side to the downstream side. At the same time, the Z-direction level at the bottom of the arc-shaped roll surface is sequentially lowered. Incidentally, the Z direction level in the y direction of the

swivel units

11, 11 on both sides is substantially constant.

The FP stand 20 arranged at the next stage of the BD stand 10 is a single unit, three rolls using a turning unit 21 as an upper unit, side unit rolls 22 and 22 as side units on both sides, and a lower unit roll 23 as a lower unit. It is a configuration.

As shown in FIG. 12, the swivel unit 21 is configured such that the endless die row 21a swivels along an elliptical endless track that is long in the direction of the pass line (y direction), and is arranged vertically on the pass line. Thus, the open pipe passing through the FP stand 20 is pressed from above. That is, the endless die row 21a is stretched between a pair of front and rear

vertical sprocket units

21b and 21b arranged at intervals in the y direction, and one or both of the pair of front and

rear sprocket units

21b and 21b rotate. By being driven, the endless die row 21a pivots on a vertical oval endless track on the pass line. The length of the turning unit 21 is set to be sufficiently smaller than the length of the pair of turning

units

11, 11 in the BD stand 10.

The endless die example 21a is configured by connecting a large number of forming dies 21c in a turning direction via a die holder 21d. Each of the molding dies 21c has an arc-shaped molding hole mold corresponding to the arc of the open pipe discharged from the BD stand 10, and the molding hole mold faces the outside of the turning ellipse. A fin 21e that fits between both edges of the open pipe is provided at the center in the circumferential direction (see FIG. 13A).

The lower part of the swivel unit 21, that is, the section along the pass line is a molding section. In this molding section, a virtual circular arc having the same diameter as the giant molding roll is placed in the molding hole mold of the endless die example 21a. The endless track is curved downward and convex so that the same radius of curvature and arc length as those of the portion are given. The upper portion of the swivel unit 21 may be linear, but here, like the lower portion, the same shape as a part of a virtual circular arc having the same diameter as the giant forming roll is formed in the forming hole mold of the endless die example 21a. The endless track was curved upward so that the radius of curvature and the arc length were given.

Since the forming die 21c in the swivel unit 21 has a large characteristic point in a forming hole mold with fins, this forming die 21c is particularly referred to as a hole die 21c, and the endless die row 21a to which the forming die 21c is connected is particularly referred to as a hole die row 21a. Called.

Each of the side unit rolls 22 and 22 and the lower unit roll 23 is a concave roll, and has an arc-shaped roll surface corresponding to the arc of the open pipe discharged from the BD stand 10.

The pair of turning

units

11 and 11 in the BD stand 10 and the turning unit 21 in the FP stand 20 at the next stage overlap each other on the close side. Specifically, it is vertically arranged above the path center between the downstream ends of the pair of

swivel units

11 and 11 arranged in a V shape when viewed from the front (that is, between the arcs convex to the downstream side). The upstream end portion of the swivel unit 21 (that is, the arc portion protruding upstream) is inserted and arranged without interference. In addition, side support rolls 31 and 31 are arranged in the proximity of the

swivel units

11 and 11 including the overlap portion 30 of the swivel unit 21 so as to sandwich the pass line from both sides, and below the pass line. One auxiliary bottom roll 32 is arranged in a position.

Here, two pairs of side support rolls 31 and 31 are arranged close to the direction of the pass line (y direction). The side support rolls 31, 31 on both sides are concave rolls that press the vicinity of both edge portions of the open pipe discharged from between the pair of turning units in the BD stand 10 from both sides, and correspond to the outer surface of the upper half of the open pipe. It has an arc-shaped roll surface. The auxiliary bottom roll 32 is a support concave roll in which the bottom roll group in the BD stand is extended to the downstream side, and is a push-up roller for correcting the warp of the open pipe. Adjustment of the push-up and push-up amount It is possible to move up and down.

The SZ stand 40 arranged at the next stage of the FP stand 20 includes upper and lower two

rolls

41 and 41 and left and right two rolls 42. On the upstream side of the SZ stand 40 (between the FP stand 20), a pair of left and right edge pressing rolls 43 that press both edge portions of the open pipe are disposed, and an auxiliary bottom roll 44 that supports the open pipe from below. Is arranged so that it can be raised and lowered. A pair of left and right edge pressing rolls 43 that press both edge portions of the open pipe are disposed on the downstream side of the SZ stand 40 (between the SZ stand 50). The edge pressing rolls 43, 43 are cage rolls in which a large number of small diameter rollers are arranged in parallel in the longitudinal direction of the raw tube.

The TW stand 50 arranged at the next stage of the SZ stand 40 has a roller beam 51 in which a plurality of small-diameter rollers are arranged in parallel along the lengthwise direction of the raw tube, at a radial position at a plurality of locations in the circumferential direction of the open pipe. A roller beam stand that can be adjusted. More specifically, on the circumference of the open pipe, the top (0 degrees), shoulder (20 degrees), side (90 degrees), bottom (180 degrees) ), Among the roller beams arranged at the side part (270 degrees) and the shoulder part (340 degrees), the roller beam arranged at the lower part (180 degrees) is replaced with the bottom roll group 52 and the top part ( The roller beam 51 (0 degree) is shortened, and a TIG welding torch 53 for outer surface welding is disposed on the downstream side thereof.

The bottom roll group 52 uses a relatively large diameter roller for all the other six roller beams 51, while using a relatively large diameter roller, and is provided with a gear at the transfer shaft end of each roller and between the rollers. A reversing gear is arranged on the main body, and all large diameter rollers are synchronously driven in the same direction. By driving the bottom roll group 52, a propulsive force can be applied to the raw pipe (open pipe) in the TW stand 50.

Next, a method for manufacturing a welded pipe using the molding apparatus and welding apparatus of the present embodiment will be described as the molding method and welding method of the present embodiment.

A strip-shaped or sheet-shaped molding material enters the BD stand 10 through each roll stand for entry guide, edge bend, and reverse bend (not shown). In the BD stand 10, the molding material passes through the molding section between the pair of turning

units

11 and 11. During this time, the molding material is supported by the bottom roll group 12 from below, while both edge portions are constrained by the swing dies 11c, 11c on both sides of the pair of

swivel units

11, 11, and synchronized with the swing dies 11c, 11c on both sides. Moving. At this time, the oscillating dies 11c and 11c on both sides oscillate downward and gradually reduce the interval so as to gradually turn the forming hole mold having the inverted L-shaped cross section downward. Thereby, a shaping | molding raw material is shape | molded from a flat plate to an open pipe, while moving a shaping | molding area.

The cross-sectional height of the molding material gradually increases as the molding material is molded from flat plate to open pipe. In order to absorb this increase in height, the plurality of concave rolls 12a in the bottom roll group 12 gradually lowers the support level from the upstream side toward the downstream side. Further, the arcs of the roll surfaces of the plurality of concave rolls 12a gradually become smaller in accordance with the change in the cross-sectional shape of the material, particularly the change in the cross-sectional shape of the bottom.

The open pipe discharged from between the pair of

swivel units

11 and 11 in the BD stand 10 enters the FP stand 20 and passes there. When the open pipe passes through the FP stand 20, the open pipe is pressed by the swivel unit 21 imagining a giant forming roll from the upper side with the fins 21 e inserted between both edges, and the side unit from both sides. Restrained by the

rolls

22 and 22 and restrained by the lower unit roll 23 from below. Thus, the open pipe finishes the fin pass process.

The open pipe that has finished the fin pass process passes through the SZ stand 40 and is further welded to the TW stand 50 by welding both edge butted portions on the outer surface by the TIG contact torch 53.

When the open pipe is delivered from the BD stand 10 to the FP stand 20, the open pipe is temporarily released. However, the pair of

swivel units

11 and 11 in the BD stand 10 and the swivel unit 21 in the FP stand 20 overlap with each other in the vicinity thereof. For this reason, the overlap release period is short. In addition, in the overlap portion 30 between the turning

units

11 and 11 and the turning unit 21, the open pipe is supported from below by the auxiliary bottom roll 32, and the edge portions on both sides are inclined by the two pairs of side support rolls 31 and 31. Pressed from above. For this reason, the big spring pack by temporary release of an open pipe does not arise. Therefore, even if the molding is a short material such as a sheet material, the formability deterioration at the material front end portion and the material tail end portion, and the material loss due to this is minimized.

In the BD stand 10, since the material support level of the plurality of concave rolls 12a constituting the bottom roll group 12 gradually decreases from the upstream side to the downstream side, the material support points of the plurality of concave rolls 12a (on the arc-shaped roll surface) The line connecting the (bottom) is a downwardly convex curve. For this reason, the open pipe discharged from the BD stand 10 tends to warp. In the overlap portion 30 between the pair of

swivel units

11 and 11 in the BD stand 10 and the swivel unit 21 in the FP stand 20, the open pipe is pressed from below by the auxiliary bottom roll 32 and is subjected to three-point bending at this portion. The warping is corrected. In particular, it is possible to completely eliminate this warping by fine level adjustment by raising and lowering the auxiliary bottom roll 32. Moreover, the roundness of the open pipe can be adjusted.

In addition to these, the BD stand 10 and the FP stand 20 can cope with tube forming of a wide range of dimensions only by performing the following work.

That is, distance adjustment including inclination angle adjustment with respect to the pass line of the pair of turning

units

11 and 11 in the BD stand 10, change and support level adjustment of the concave roll 12 a in the bottom roll group 12, and die exchange of the turning unit 21 in the FP stand 20. , Exchange of the pair of side unit rolls 22 and 22, adjustment of the interval, exchange of the lower unit roll 23 and adjustment of the support level, and exchange of the side support rolls 31 and 31 in the overlap portion 30 of the turning

units

11 and 11 and the turning unit 21 For example, interval adjustment, replacement of the auxiliary bottom roll 32 and level adjustment.

Next, another embodiment of the present invention will be described. In the molding apparatus of this embodiment, the fins 21e are omitted from the hole die 21c in the turning unit 21 of the FP stand 20, and instead, as shown in FIG. Is provided at the position of the fin 21e, that is, at the center in the circumferential direction of the arc-shaped forming hole mold, so that both edge portions of the open pipe are abutted in the FP stand 20.

Further, a mandrel is inserted into the open pipe from the BD stand 10 and extended into the FP stand 20, and both edge butted portions of the open pipe are tack-welded by laser welding from the inner surface side in the FP stand 20 (inner surface temporary welding). The open pipe coming out of the FP stand 20 passes through the SZ stand 40 and is then subjected to outer surface welding at the TW stand 50. When the forming material is a sheet material, it is reasonable to perform the external surface welding offline. When the outer surface welding is performed off-line, the TW stand 50 and the edge pressing roll 41 between the SZ stand 40 and the TW stand 50 are omitted. Other configurations are substantially the same as those of the above-described embodiment.

Thus, the welded pipe product or the open pipe that has been tack welded, that is, the semi-finished product of the welded pipe, is discharged from the forming apparatus.

As the welding method here, for example, plasma welding, TIG welding and the like are possible in addition to laser welding. Depending on the type of welding (for example, in plasma welding), as shown in FIG. 13 (c), the concave relief portion 21f can be omitted from the hole die 21c.

The characteristic points of the molding method and apparatus of the present invention are enumerated based on the embodiment as follows.

In the BD stand 10, the combination of the pair of

swivel units

11 and 11 and the bottom roll group 12 enables efficient and good molding. In the FP stand 20 as well, an efficient and good moldability is formed by using the swivel unit 21 for the upper unit and the molding rolls 22, 22 and 23 for the side units on both sides and the lower unit. Can do. As a result, from the breakdown start to the end of the fin pass can be carried out with only two stands, and the line length can be greatly reduced.

In the FP stand 20, the turning unit 21 is used for the upper unit, and the molding rolls 22, 22, and 23 are used for the side units on both sides and the lower unit, so that the equipment can be made smaller. It is easy to change the setup according to the size change. In the BD stand 10 as well, the setup change accompanying the size change is easy. For these reasons, a wide variety of products can be molded in one line, and the equipment cost can be greatly reduced.

After the pair of

swivel units

11 and 11 in the BD stand 10 and the swivel unit 21 in the FP stand 20 are overlapped, an auxiliary bottom roll 32 and a pair of side support rolls 31 and 31 are placed on the overlap portion 30. Since it arrange | positions, the spring back of an open pipe between the BD stand 10 and the FP stand 20 can be prevented effectively. For this reason, it is possible to suppress unsteady deformations such as sagging at the material front end and material tail end, which are particularly problematic when a sheet material is used as a molding material, thereby enabling the molding of the sheet material. At the same time, material loss due to deformation of both ends can be eliminated.

Thus, according to the molding method and apparatus of the present embodiment, the number of steps is small while suppressing unsteady deformation such as sagging at the front end and tail end of the material, which is particularly problematic when a sheet material is used as the molding material. A round tube having a diameter of several inches to several tens of inches can be manufactured by (number of steps, number of stands).

In addition, according to the molding method and apparatus of the present embodiment, the auxiliary bottom roll 32 disposed in the overlap portion 30 between the pair of turning

units

11 and 11 in the BD stand 10 and the turning unit 21 in the FP stand 20 can be moved up and down. By making the level adjustment possible, it is possible to effectively prevent the warpage that occurs in the material in the BD stand 10. The auxiliary bottom roll 32 not only prevents the spring back of the open pipe at the overlap portion 30 but also contributes to correcting the upper warp of the open pipe. In addition, the roundness of the open pipe can be adjusted.

Moreover, the moldability in the BD stand 10 is good, and the deterioration of the moldability with the FP stand 20 is prevented by the overlap portion 30 as much as possible. It is possible to omit the fin 21e from the die 21c, and thereby even inner surface temporary welding at the FP stand 20 is possible. Then, the inner surface temporary welding in the FP stand 20 can further improve the formability, and in particular, the limit for forming a thin material can be expanded.

Further, according to the welding method and apparatus of the present embodiment, in the FP stand 20, the open pipe is reliably held in the two directions of the center line direction (line direction) and the circumferential direction of the open pipe. In other words, the FP stand 20 has a short length in the line direction and good open pipe retention. For this reason, it is possible to externally weld both edges of the open pipe with the TW stand 50 of the next stage only by increasing the roundness of the open pipe with the SZ stand 40 of the next stage. Thus, according to the welding method and apparatus of the present embodiment, it is possible to manufacture a high-quality welded tube with a small number of steps (number of steps, number of stands) even when the molding material is a sheet material.

In the FP stand 20, since each hole die in the swivel unit 21 is a finned die, the holdability of the open pipe in the circumferential direction is particularly good, which is favorable for the welding quality in the TW stand 50. Needless to say, it has an influence. In addition, if the upper roll 41 is a finned roll in the SZ stand 40, the holding performance in the circumferential direction of the open pipe entering the TW stand 50 is further improved, and the outer surface welding quality at the TW stand 50 is further improved. improves.

Still another embodiment of the present invention will be described with reference to FIGS. This embodiment is a pipe welding apparatus (outer surface welding apparatus), and here, it is applied to a pipe mill whose basic structure is shown in FIG. As described above, the pipe mill includes the BD stand 10, the FP stand 20, the SZ stand 40, and the TW stand 50 that are arranged from the upstream side to the downstream side. That is, the FP stand 20 includes a turning unit 21 in which fins are provided on the hole surface of each hole die. The SZ stand 40 includes upper and lower two rolls 41 and left and right two rolls 42.

The welding apparatus of the present embodiment is different from the welding apparatus employed in the pipe mill of FIG. 14 in that a pair of upper and lower inner surface support rollers that abut the upper inner surface and lower inner surface of the open pipe at the throttle position of the SZ stand 40. 45 and 45 are arranged.

The pair of upper and lower inner

surface support rollers

45, 45 are rotatably supported by a mandrel 60 inserted into the open pipe from the overlap portion 30 between the BD stand 10 and the FP stand 20. That is, the mandrel 60 extends from the overlap portion 30 between the BD stand 10 and the SZ stand 20 to the SZ stand 40, and the base end portion of the mandrel 60 is a support stand for the side support roll 31 disposed on the overlap portion 30. Installed on. A pair of upper and lower inner

surface support rollers

45, 45 in the SZ stand 40 are rotatably supported at the tip of the mandrel 60. Both rollers are driven in the radial direction of the open pipe by a spring or hydraulic pressure with respect to the mandrel 60.

When the inner

surface support rollers

45, 45 are arranged in the vicinity of the throttle position of the SZ stand 40 and the molding is performed, the contact state between the end surfaces of both edges of the open pipe to be welded becomes good, and the TW stand is subsequently performed. The quality of the outer surface welding at 50 is constant and good.

In the welding apparatus of this embodiment, in addition to the inner

surface support rollers

45, 45, or instead of the inner

surface support rollers

45, 45, the upper roller 41 in the SZ stand 40 may be a finned roller to improve the welding quality. Effective above. When the upper roller 41 in the SZ stand 40 is a finned roller, the holding performance of the open pipe in the circumferential direction in the SZ stand 40 is improved, and overlapping of both edge portions is prevented, so that the outer surface welding in the TW stand 50 is performed. The quality is further improved.

Since the fins provided on the upper roll 41 of the SZ stand 40 are extremely effective for holding the open pipe, the inner

surface support rollers

45 and 45 can be omitted. Incidentally, the upper inner surface support roller 45 restrains both edge portions by sandwiching both edge portions of the open pipe between the upper roller 41.

Still another embodiment of the present invention will be described with reference to FIGS. This embodiment is a pipe welding apparatus (outer surface welding apparatus), and here, as in the embodiment shown in FIGS. 15 and 16, it is applied to a pipe mill whose basic configuration is shown in FIG.

The welding apparatus of this embodiment is different from the welding apparatus employed in the pipe mill of FIG. 14 in that a pair of upper and lower inner surfaces that support the upper inner surface and the lower inner surface of the open pipe at the drawing position of the SZ stand 40 are supported. A pair of upper and lower inner

surface support rollers

25, 25 for abutting and supporting the upper inner surface and lower inner surface of the open pipe from the throttle position of the FP stand 20 to the upstream side thereof (see FIG. 18). ), A finned inner surface support roller 26 (FIG. 19) for abutting and supporting the upper inner surface of the open pipe, and an inner surface support roller 27 (FIG. 20) for abutting and supporting the upper inner surface of the open pipe. .

The hole die constituting the swivel unit 21 of the FP stand 20 has fins.

These inner surface support rollers are rotatably supported by a mandrel 60 inserted into an open pipe from an overlap portion 30 between the BD stand 10 and the FP stand 20. That is, the mandrel 60 extends from the overlap portion 30 between the BD stand 10 and the FP stand 20 to the SZ stand 40, and the base end portion of the mandrel 60 is a support stand for the side support roll 31 disposed on the overlap portion 30. Installed on. A pair of upper and lower inner

surface support rollers

45 and 45 in the SZ stand 40 are rotatably supported at the distal end portion of the mandrel 60, and a pair of upper and lower inner surface support rollers 25 in the FP stand 20 are supported in the vicinity of the base end portion. , 25, finned inner surface support roller 26, and inner surface support roller 27 are rotatably supported. Both rollers are driven in the radial direction of the open pipe by a spring or hydraulic pressure with respect to the mandrel 60.

A pair of upper and lower inner

surface support rollers

25, 25 and a finned inner surface support roller 26 are disposed in the vicinity of the FP stand 20 in the aperture position, and inner

surface support rollers

45, 45 are disposed in the vicinity of the SZ stand 40 in the aperture position. Then, the sizing function in the FP stand 20 and the rolling prevention effect of the open pipe are synergistic, so that the butting positions of both edge end surfaces to be welded of the open pipe are maintained as prescribed, and the molding quality is improved. Coupled with the effect of the inner

surface support rollers

45, 45 in the SZ stand 40, the quality of the outer surface welding in the subsequent TW stand 50 is further constant and improved.

As for the inner surface support roller in the FP stand 20, a pair of upper and lower inner

surface support rollers

25, 25 are essential, and it is preferable to combine a finned inner surface support roller 26 for the upper inner surface on the upstream side, and further on the upper side on the upper side. More preferably, the inner surface support roller 27 for the inner surface is combined.

Of the inner

surface support rollers

45, 45 in the SZ stand 40, the inner surface support roller 45 for the upper inner surface can be a finned roller. The upper roll 41 of the SZ stand 40 can also be a finned roll. In that case, the inner surface support roller 45 for the upper inner surface is a finless roller.

Still another embodiment of the present invention will be described with reference to FIG. This embodiment is a pipe welding apparatus (outer surface welding apparatus). Here, the basic configuration shown in FIG. 14 is the same as the embodiment shown in FIGS. 15 and 16 and the embodiment shown in FIGS. Applied to the indicated pipe mill.

The welding apparatus of the present embodiment is different from the welding apparatus employed in the pipe mill of FIG. 14 in that the outer surface welding means is arranged from the TW stand 50 to the SQ stand 70 between the FP stand 20 and the SZ stand 40. It is a point changed to. That is, the SQ stand 70 is arranged at the next stage of the FP stand 20, and the SZ stand 40 is arranged at the next stage.

The SQ stand 70 includes a three-way roll stand arranged in two stages along a line, and a welding torch arranged from the upper side toward the roll drawing position between the three-way roll stands. The three-way roll stand includes a lower roll 71 that supports the open pipe from below, and left and right upper rolls 72 that press the vicinity of both edge portions of the open pipe obliquely from above.

As the SZ stand 70, in addition to the illustrated roll type, a pair of swiveling units are horizontally arranged on both sides of the line and the open pipe is supported from both sides, or the type disclosed in FIG. Can be adopted. As the welding torch, a laser welding type, a plasma welding type, a TIG welding type, or the like can be used, and an electric resistance welding apparatus can be used instead of the welding torch.

In the welding apparatus of the present embodiment, the open pipe after BD forming is held and shaped by the FP stand 20, both edge portions are butted and welded to the outer surface by the SQ stand 70 of the next stage, and then the SZ stand of the next stage. As a result of being shaped into a welded pipe at 40, it is possible to produce high-quality welded pipes with a small number of steps (number of steps, number of stands), not only when the molding material is a coil material but also a sheet material. It becomes possible.

Here, the hole die constituting the turning unit 21 of the FP stand 20 is provided with fins. The upper roll of the SZ stand 40 has no fins since the welded pipe passes through it.

Still another embodiment of the present invention will be described with reference to FIGS. The present embodiment is a pipe welding apparatus (inner surface temporary welding apparatus). Here, the embodiment shown in FIGS. 15 and 16, the embodiment shown in FIGS. 17 to 20, and the embodiment shown in FIG. Like FIG. 14, the basic configuration is applied to the pipe mill shown in FIG.

The welding apparatus of this embodiment differs from the welding apparatus employed in the pipe mill of FIG. 14 in that the FP stand 20 is a squeeze type FP in which fins are excluded from the hole type surfaces of the hole type dies 21c in the turning unit 21. A change to a stand (see FIG. 13C), a pair of upper and lower inner surfaces that support the upper inner surface and the lower inner surface of the open pipe from the throttle position of the squeeze type FP stand 20 to the upstream side thereof Rollers 25 and 25 (FIGS. 22 and 23), a finned inner surface support roller 26 (FIG. 24) for abutting and supporting the upper inner surface of the open pipe, and an inner surface support roller 27 for abutting and supporting the upper inner surface of the open pipe In the squeeze type FP stand 20, a welding torch 28 (FIG. 22) for inner surface temporary welding of an open pipe is disposed, and outer surface welding means (T Is that is omitted stand 50, SQ stand 70).

With respect to the inner surface support roller in the squeeze type FP stand 20, the upper inner surface support roller 25 of the pair of upper and lower inner

surface support rollers

25, 25 is displaced upstream of the throttle position (FIG. 23), and the lower inner surface support roller is supported. The roller 25 is disposed at the aperture position (FIG. 22). Further, the finned inner surface support roller 26 is positioned upstream of the upper inner surface support roller 25, and the inner surface support roller 27 is positioned further upstream of the finned inner surface support roller 26. And the welding torch 28 for inner surface welding is arrange | positioned with respect to the empty space (upper inner surface of a throttle position) formed by the upper inner surface support roller 25 being displaced (FIG. 22).

These inner surface support rollers are rotatably supported by a mandrel 60 inserted into an open pipe from an overlap portion 30 between the BD stand 10 and the squeeze type FP stand 20. That is, the mandrel 60 extends from the overlap portion 30 between the BD stand 10 and the squeeze-type FP stand 20 to the throttle position of the squeeze-type FP stand 20, and its base end portion is disposed at the overlap portion 30. The side support roll 31 is attached to a support stand. The mandrel 60 rotatably supports a pair of upper and lower inner

surface support rollers

25, 25, a finned inner surface support roller 26, and an inner surface support roller 27 in the squeeze type FP stand 20. Both rollers are driven in the radial direction of the open pipe by a spring or hydraulic pressure with respect to the mandrel 60.

A welding torch 28 for inner surface welding is disposed at the throttle position of the squeeze type FP stand 20, and a pair of upper and lower inner

surface support rollers

25, 25, a finned inner surface support roller 26, and an inner surface support roller 27 are disposed from the throttle position to the downstream side. When the molding is carried out, the sizing function of the squeeze type FP stand 20 and the rolling prevention effect of the open pipe are synergistic, so that the butt positions of both edge end surfaces to be welded of the open pipe are held as prescribed. As a result of maintaining the welding seam position constant, extremely high quality inner surface temporary welding is performed.

The pipe after the inner surface temporary welding can be turned into a welded pipe online by outer surface welding using a TW stand 50 or the like arranged on the downstream side of the SZ stand 40. Moreover, it is also possible to make a welded pipe by performing external surface welding offline.

As for the inner surface support roller in the squeeze type FP stand 20, a pair of upper and lower inner

surface support rollers

25, 25 are preferable, and it is more preferable to combine a finned inner surface support roller 26 for the upper inner surface on the upstream side, and further on the upstream side. It is further preferable to combine an inner surface support roller 27 for the upper inner surface.

As for the welding torch 28 for inner surface welding, a laser irradiation type is used here, but any of known ones such as plasma and TIG can be used.

Example 1
Assumes a dual-use pipe mill that can produce various types of round pipes that are made of stainless steel, plain steel, and high-tensile steel, and that have a diameter of 38.1 to 114.3 mm and a thickness of 0.5 to 6.0 mm. The entry guide stand, edge bend roll stand, reverse bend roll stand, ODF / BD stand, ODF / FP stand, sizing roll stand, squeeze roller beam stand are arranged in this order from the material entry side. Furthermore, the equipment of each stand was designed using commercially available 3D CAD software and the original automatic design and FEM analysis software designed by the inventor.

The entry guide stand has a structure in which a known side roll and an upper and lower roll are combined. The edge bend roll stand is a combination of a pair of upper rolls that can move and rotate in the material width direction and a pair of lower rolls that can move in the material width direction and move in the height direction. It was set as the structure which can be combined with respect to the aperture of. The reverse bend roll stand is configured by combining a known side roll and an upper and lower roll.

In the ODF / BD stand and the ODF / FP stand, the configuration described in the above embodiment, particularly, as a basic structure, a ball bearing in which a large number of small balls run in an elliptical orbit is built in the unit and swiveled. A track structure that supports the turning of the unit was adopted, and a swing arm and pinion was adopted as a mechanism for swinging each die to reduce the size of the entire apparatus. The BD stand and FP stand are arranged close to each other, and the side support roll and auxiliary bottom roll have the same configuration.

The sizing roll stand is configured by combining known upper and lower rolls. The squeeze roller beam stand is a roller beam in which a large number of small-diameter rollers are arranged in parallel along the longitudinal direction of the tube so that the formed tube is inserted into and held in a short cylindrical frame. At the top (0 degrees), shoulder (20 degrees), side (90 degrees), bottom (180 degrees), side (270 degrees), shoulder (340 degrees) A configuration was adopted in which the position of the frame can be adjusted in the radial direction. The roller beam at the top is short and a TIG welder was placed near the downstream.

As a result of actually manufacturing an actual machine based on this design, a 4 inch pipe mill with a line length of only 5 m from the entry guide stand EG stand to the squeeze roller stand SQ stand was obtained.

ODF / BD stand is x direction (w) 2920mm, y direction 2510mm, z direction (h) 2950mm,
BD swivel unit is x direction 710mm, y direction 2500mm, z direction 300mm, weight 1990kg,
ODF / FP stand is 1300mm in x direction, 955mm in y direction, 1600mm in z direction,
The FP swivel unit was 210 mm in the x direction, 930 mm in the y direction, 465 m in the z direction, and weighed 405 kg.

As the forming material, a coil material and a sheet material (length: 1.5 to 4 m) having a material and a plate thickness t of the following six types and a plate width corresponding to a diameter of 45 mm and a diameter corresponding to 114.3 mm were used.

SUS304, t0.7mm,
X65-70 equivalent material (YS = 544MPa), t1.0mm
X120 equivalent material (YS = 897MPa), t1.0mm
X100 equivalent material (YS = 761MPa), t2.0mm
SS400 (YS = 308MPa), t3.2mm
SS400 (YS = 321MPa), t4.5mm

First, a total of 12 types of round tubes, 6 types of materials and 2 types of diameters, were formed and manufactured using coil materials. In either case, a round tube with the same caliber, roundness, and straightness could be produced.

Next, a total of 36 types of round tubes are formed and manufactured using sheet materials having lengths of 1.5 m, 2.0 m, and 4.0 m, material and thickness t of the above six types, and plate width of the above two types. did. In the case of a sheet material, in order to improve weldability, a measure to connect a tab to the edge portion of the tip portion was adopted. No matter the length of the sheet material, there will be no deformation such as sagging at the tip and end of the resulting round tube, and it will be possible to produce round tubes with the same diameter, roundness and straightness as designed. It was.

In addition, it was confirmed that the actual measurement values such as the molding load in each process during the manufacturing described above substantially coincided with the calculated values at the time of design using the FEM analysis software.

Example 2
The mold of the swivel unit of the ODF / FP stand in Example 1 had the fins shown in FIG. 5 (a), but in Example 2, the cross-sectional hemispheric surface without fins shown in FIG. 5 (c). A seat-shaped mold was used. In addition, another stand is placed between the ODF / BD stand and the ODF / FP stand at the position directly above the return part of the ODF / BD swivel unit, and an L-shaped mandrel is suspended from the stand in the tube. A YAG pulsed fiber laser welder with a laser torch mounted upwards was placed by guiding the tip of the mandrel into the molding section position of the ODF / FP stand. Therefore, this ODF stand is called an ODF / weld stand.

With this configuration, immediately after forming into a round tube with a BD stand, when constrained in a mold with a semispherical seat section of the ODF / weld stand, spot welding is performed from the inner surface of the tube with a laser welding machine. Temporary welding can be performed. Thereafter, the sizing process and the welding process from the outer surface can be performed in the same manner as in the first embodiment.

A total of four types of rounds were used, using the sheet materials having lengths of 1.5 m and 2.0 m, material equivalent to X120 (t1.0 mm), plate width equivalent to 45 mm diameter and equivalent to 114.3 mm diameter used in Example 1. A pipe, that is, a round pipe subjected to inner surface temporary welding and outer surface welding was formed and manufactured. No matter the length of the sheet material, no deformation such as sagging occurs at the tube tip and the tube end, the inner and outer surfaces are well welded, and have the same caliber, roundness, and straightness as designed. A round tube was produced.

Example 3
Various sizes with material equivalent to X65 to 70 (YS = 544MPa), equivalent to X100 (YS = 761MPa), equivalent to X120 (YS = 897MPa), caliber 323.9mm to 762.0mm, plate thickness 4.8mm to 25.4mm Entry guide stand, edge bend roll stand, reverse bend roll stand, ODF / BD stand, ODF / weld stand, sizing roll stand The squeeze roller beam stands are arranged in order, and the equipment for each stand is designed using commercially available 3D CAD software and original automatic design and FEM analysis software designed by the inventor, as in Example 1. did.

As a result of this design, a 30-inch pipe mill with a line length of 38 m from the EG stand to the SQ stand was obtained.

ODF / BD stand is x direction (w) 10m, y direction 20m, z direction (h) 6.8m,
BD swivel unit is 2m in x direction, 15m in y direction, 1.2m in z direction, weight 127ton,
ODF / FP stand is x direction 4.5m, y direction 3.9m, z direction 6.5m,
The FP swivel unit had an x direction of 1.0 m, a y direction of 3.9 m, a z direction of 2.1 m, and a weight of 28 tons.

Based on the calculated values at the time of design using simulation software and FEM analysis software, the X120 equivalent material (YS = 897MPa), round tube with a diameter of 323.9mm, plate thickness of 19.1mm, and the same material with a diameter of 762.0mm, plate thickness of 25.4 It was confirmed that a round tube of mm could be manufactured.

Example 4
In a 4-inch pipe mill whose basic structure is shown in FIG. 14, a welded round tube was actually formed and manufactured using the welding apparatus shown in FIGS. The pipe mill includes a BD stand 10, an FP stand 20, an SZ stand 40 and a TW stand 50 arranged in order from the upstream side to the downstream side. The material is stainless steel, ordinary steel, high strength steel, and the diameter is 38. Various round tubes having a thickness of 1 to 114.3 mm and a thickness of 0.5 to 6.0 mm can be manufactured.

Then, using the mandrel 60 inserted into the open pipe from the overlap portion 30 of the BD stand 10 and the FP stand 20, the upper inner surface of the open pipe is placed at the throttle position where the axes of the four-way rolls in the SZ stand 40 are aligned. Also, a pair of upper and lower inner

surface support rollers

45, 45 that contact and support the lower inner surface are disposed. The inner

surface support rollers

45, 45 can be moved up and down in the radial direction of the open pipe by a spring.

As the forming material, two types of coil materials having a plate width equivalent to a diameter of 114.3 mm, a material equivalent to X120 (YS = 897 MPa), and a plate thickness t of 1.0 mm and 2.0 mm are used. A TIG welder was arranged to form and manufacture two types of welded round tubes with different plate thicknesses. By arranging a pair of upper and lower inner

surface support rollers

45, 45 at the throttle position of the SZ stand 40, the contact state between the end surfaces of both edges of the open pipe to be welded becomes good, and the quality of the outer surface welding is constant and good. As a result, it was possible to produce a welded round tube with a caliber, roundness, and straightness as designed.

Example 5
The welding apparatus used in Example 4 was replaced with that shown in FIGS.

That is, using the mandrel 60 inserted into the open pipe from the overlap portion 30 of the BD stand 10 and the FP stand 20, the upper inner surface of the open pipe is placed at the throttle position where the axes of the four-way rolls in the SZ stand 40 are aligned. In addition, a pair of upper and lower inner

surface support rollers

45, 45 for abutting and supporting the lower inner surface are disposed, and the upper inner surface and the lower inner surface of the open pipe are abutted and supported from the throttle position in the FP stand 20 to the upstream side thereof. A pair of upper and lower inner

surface support rollers

25, 25, a finned inner surface support roller 26 that abuts and supports the upper inner surface of the open pipe, and an inner surface support roller 27 that abuts and supports the upper inner surface of the open pipe are arranged. All of the inner

surface support rollers

45, 45 and 25, 25, 26, and 27 can be moved up and down in the radial direction of the open pipe by a spring.

A coil material with a plate width equivalent to 114.3 mm, a material equivalent to X120 (YS = 897 MPa), and a plate thickness t of 1.0 mm and 2.0 mm is used. Then, two types of welded round tubes having different plate thicknesses were formed and manufactured.

In addition to the pair of upper and lower inner

surface support rollers

45, 45 disposed at the throttle position of the SZ stand 40, the pair of upper and lower inner

surface support rollers

25, 25 and the finned inner surface support roller 26 for the upper inner surface are disposed at the throttle position of the FP stand 20. Since the sizing function of the FP stand 20 and the rolling prevention effect of the open pipe are synergistic with each other by arranging the inner surface support roller 27 for the upper inner surface, the butted position of both edge end surfaces to be welded of the open pipe Is maintained as prescribed to improve the molding quality, and the effect of the inner

surface support rollers

45, 45 in the SZ stand 40 is added, so that the quality of the outer surface welding at the TW stand 50 becomes even more constant and good. Was able to produce a welded round tube with the same diameter, roundness and straightness as designed.

Example 6
The welding apparatus used in Example 4 was replaced with that shown in FIGS.

That is, the FP stand 20 was changed to a squeeze type FP stand in which fins were excluded from the hole mold surface of each hole mold 21c in the turning unit 21. In addition, a welding torch 28 for inner surface welding is disposed at the throttle position in the squeeze type FP stand 20 by using a mandrel 60 inserted into the open pipe from the overlap portion 30 between the BD stand 10 and the squeeze type FP stand 20. Further, from the throttle position to the upstream side, a pair of upper and lower inner

surface support rollers

25 and 25 for abutting and supporting the upper inner surface and lower inner surface of the open pipe, and an inner surface support roller with fins for abutting and supporting the upper inner surface of the open pipe 26 and an inner surface support roller 27 that contacts and supports the upper inner surface of the open pipe.

The welding torch 28 is a laser torch capable of irradiating two beams upward on the aperture point of the side unit roll in the squeeze type FP stand 20, and is equipped in the YAG pulse fiber laser welding machine. All of the inner

surface support rollers

25, 25, 26 and 27 can be moved up and down in the radial direction of the open pipe by a spring.

A coil material having a plate width of 114.3 mm equivalent, a material of X120 equivalent (YS = 897 MPa), and a plate thickness t of 1.0 mm and 2.0 mm is used. Two types of welded round tubes with different plate thickness were formed and manufactured.

By combining the sizing function of the squeeze type FP stand 20 and the anti-rolling effect of the open pipe, the abutting positions of both edge end surfaces to be welded of the open pipe are maintained as prescribed, and the weld seam position is kept constant. As a result, an extremely high quality internally welded pipe was produced.

TW stand 50 was arranged on the downstream side of SZ stand 40 and outer surface welding was performed following inner surface welding. A 2 m long steel pipe could be manufactured.

Example 7
In the 4-inch pipe mill having the basic configuration shown in FIG. 14, the swivel unit 21 having the fins 21 a shown in FIG. 13A is used as the mold, and the SZ stand 40 includes the upper and lower rolls 41. As the roll 41, a roll having the same shape as that of the mold section was used.

This pipe mill includes a BD stand 10, an FP stand 20, an SZ stand 40, and a TW stand 50 arranged in order from the upstream side to the downstream side. Various round tubes having a thickness of 1.1 to 114.3 mm and a thickness of 0.5 to 6.0 mm can be manufactured.

As a forming material, a sheet material having a plate width equivalent to 114.3 mm, lengths of 1.5 m and 2.0 m, a plate thickness t of 1.0 mm, and a material equivalent to X70 (YS = 544 MPa) is used. In the TW stand 50, two types of high-strength steel welded round tubes having different lengths were manufactured using a TIG welder.

Further, as a forming material, a sheet material having a plate width of 114.3 mm, a length of 1.5 m and 2.0 m, a plate thickness t of 0.7 mm, and a material of SUS304 is used. Two types of stainless steel welded round tubes with different lengths were manufactured using a welder.

By using a finned roll for the upper roll 41 of the SZ stand 40, both edges of the open pipe are planned to be welded without connecting a tab to the end edge, even though the molding material is a sheet material. The contact state between the end faces is good, and the quality of the outer surface welding is kept constant and good.As a result, in any of the four types, there is no deformation at the pipe tip or pipe tail, Welded round tubes with roundness and straightness were manufactured.

A sheet material having a plate width of 4 inches, a plate thickness of 0.7 mm, and a length of 1.5 m is equivalent to a sheet material having a plate thickness of 25.4 mm and a length of 12 m when the diameter is 30 inches. Also in the 30-inch pipe mill of Example 3, a round tube having a diameter of 762.2 mm, a plate thickness of 25.4 mm, and a length of 12 m can be manufactured by using a finned roll as the upper roll 41 of the SZ stand 40. confirmed.

A sheet material having a plate width of 4 inches, a plate thickness of 0.7 to 1.0 mm, and a length of 1.5 to 2.0 m has a plate thickness of 4.7 to 6. This corresponds to a sheet material having a length of about 7 mm and a length of about 12 m. Also in the simulation test by the 30-inch pipe mill of Example 3 using the pipe making data by the above-mentioned actual machine, using a finned roll as the upper roll 41 of the SZ stand 40, the diameter is 762.2 mm and the plate thickness is 5 mm. It was confirmed that a round tube having a length of 12 m and a T / D of less than 1% can be produced.

10 BD stand 11 Rotating unit 11a Endless die row (oscillating die row)
11b Sprocket unit 11c Molding die (oscillating die)
11d Die holder 20 FP stand 21 Turning unit 21a Endless die example (hole die array)
21b Sprocket unit 21c Molding die (hole die)
21d Die holder 21e Fin 21f Concave part 22 Side unit roll 23

Lower unit roll

24, 26 Inner surface support roller 27 Inner surface support roller with fin 28 Welding torch for inner surface temporary welding 30 Overlap portion 31 Side support roll 32 Auxiliary bottom roll 40 SZ Stand 41 Upper and lower rolls 42 Left and right rolls 43 Edge pressing roll 44 Auxiliary bottom roll 45 Inner surface support roller 50 TW stand (welding means)
51 Roller beam 52 Bottom roll 53 Welding torch for outer surface welding 60 Mandrel 70 SQ stand (welding means)
71 Lower roll 72 Upper roll

Claims

A pair of swivel units, which support a swivel die row in which endless swivel dies, each having a forming hole mold facing outwardly and swingably connected, can be swung on an endless track, are linearly spaced between them. Oppositely arranged so as to form a gradually decreasing molding section, while supporting the molding material entering the molding section with the bottom roll group, both edge portions of the molding material are constrained by the molding hole molds on both sides and moved synchronously. A BD stand that continuously bends the molding material into an open pipe by changing the swing angle of the mold hole molds on both sides,
A die array, in which a hole die with the mold hole facing outward, is connected to an endless row so as to be able to swivel on an endless track, and a radius that assumes a giant forming roll in a part of the hole shape in the swivel direction The swivel unit with a circular arc is used for the upper unit, and the lower unit and the FP stand using the rolls for the side unit are arranged in series,
A pipe forming method in which a pair of turning units in a BD stand and a turning unit in an FP stand are arranged close to each other to form a pipe.
The method for forming a pipe according to claim 1, wherein
In order to overlap the swivel unit between the BD stand and the FP stand, the swivel return part on the upstream side of the swivel unit in the FP stand is inserted and arranged between the swivel return parts on the downstream side of the pair of swivel units in the BD stand. A method of forming a pipe.
The method for forming a pipe according to claim 1, wherein
A method of forming a pipe, wherein a pair of side support rolls capable of pressing an open pipe exiting a BD stand from both sides is disposed in the vicinity of the swivel unit to form a pipe.
The method for forming a pipe according to claim 1, wherein
A tube forming method for forming a tube by extending a bottom roll group in a BD stand to a proximity portion between a pair of turning units in the BD stand and a turning unit in the FP stand.
The method for forming a pipe according to claim 1, wherein
One or more side support rolls capable of pressing the open pipe that has exited the BD stand from both sides are disposed in the vicinity of the pair of turning units in the BD stand and the turning unit in the FP stand, and a bottom roll group in the BD stand is provided. A method of forming a tube, wherein the tube is formed by being extended to an overlap portion of the swivel unit.
The method for forming a pipe according to claim 1, wherein
The bottom roll group in the BD stand is a method of forming a pipe composed of a plurality of concave rolls in which the roll surface becomes an arc surface with a small radius sequentially from an arc surface with a large radius.
The method for forming a pipe according to claim 1, wherein
A pipe forming method in which an auxiliary bottom roll is disposed so as to be movable up and down on the upstream side of a lower roll in an FP stand, and a pipe is formed by adjusting a pass line height of the auxiliary bottom roll.
The method for forming a pipe according to claim 1, wherein
An auxiliary bottom roll is arranged on the upstream side of the lower roll in the FP stand so that the auxiliary bottom roll can be moved up and down, and an SZ stand made up of two upper and lower two rolls or four upper, lower, left and right rolls is arranged next to the FP stand. And forming a tube by adjusting the drawing amount in the FP stand, the drawing amount in the SZ stand, and the pass line height of the auxiliary bottom roll.
The method of forming a tube according to claim 8,
A method for forming a tube, wherein the upper roll in the SZ stand is a finned roll.
The method for forming a pipe according to claim 1, wherein
A method for forming a tube, wherein each hole die in each swivel unit of the FP stand is a finned die in which a fin is provided at the center of the inner surface.
The method for forming a pipe according to claim 1, wherein
A method of forming a tube in which fins are removed from the center of the inner surface of each hole die in each swivel unit of the FP stand, or a groove is provided in the center of the inner surface of each hole die to form the FP stand as a squeeze type.
A pair of swivel units, which support a swivel die row in which endless swivel dies, each having a forming hole mold facing outwardly and swingably connected, can be swung on an endless track, are linearly spaced between them. Oppositely arranged so as to form a gradually decreasing molding section, while supporting the molding material entering the molding section with the bottom roll group, both edge portions of the molding material are constrained by the molding hole molds on both sides and moved synchronously. A BD stand that continuously bends the molding material into an open pipe by changing the swing angle of the mold hole molds on both sides,
A die array, in which a hole die with the mold hole facing outward, is connected to an endless row so as to be able to swivel on an endless track, and a radius that assumes a giant forming roll in a part of the hole shape in the swivel direction The swivel unit with a circular arc is used for the upper unit, and the lower unit and the FP stand using the rolls for the side unit are arranged in series,
A pipe forming apparatus in which a pair of swivel units in a BD stand and a swivel unit in an FP stand are arranged close to each other.
The pipe forming apparatus according to claim 12, wherein
In order to allow the swivel unit to overlap between the BD stand and the FP stand, a swivel return portion on the upstream side of the swivel unit in the FP stand is inserted between the swivel return portions on the downstream side of the pair of swivel units in the swivel unit BD stand. An apparatus for forming the arranged pipes.
The pipe forming apparatus according to claim 12, wherein
A pipe forming apparatus in which a pair of side support rolls capable of pressing an open pipe that has exited a BD stand from both sides is disposed in the vicinity of a pair of turning units in the BD stand and a turning unit in the FP stand.
The pipe forming apparatus according to claim 12, wherein
A tube forming apparatus in which a bottom roll group in a BD stand is extended to a proximity portion between a pair of turning units in the BD stand and a turning unit in the FP stand.
The pipe forming apparatus according to claim 12, wherein
One or more side support rolls that can press the vicinity of the edge of the open pipe that has come out of the BD stand are arranged in the vicinity of the swivel unit, and the bottom roll group in the BD stand is extended to the overlap part of the swivel unit. Pipe forming equipment.
The pipe forming apparatus according to claim 12, wherein
The bottom roll group in the BD stand is a pipe forming apparatus composed of a plurality of concave rolls in which the roll surface becomes an arc surface with a small radius sequentially from an arc surface with a large radius.
The pipe forming apparatus according to claim 12, wherein
An apparatus for forming a pipe in which an auxiliary bottom roll is disposed so as to be movable up and down in the vicinity of the lower roll on the upstream side of the lower roll in the FP stand, and the pass line height of the auxiliary bottom roll can be adjusted.
The pipe forming apparatus according to claim 12, wherein
An auxiliary bottom roll is arranged on the upstream side of the lower roll in the FP stand so that the auxiliary bottom roll can be moved up and down, and an SZ stand made up of two upper and lower two rolls or four upper, lower, left and right rolls is arranged next to the FP stand. And a pipe forming apparatus capable of adjusting the drawing amount in the FP stand, the drawing amount in the SZ stand, and the pass line height of the auxiliary bottom roll.
The pipe forming apparatus according to claim 19, wherein
A pipe forming apparatus in which the upper roll in the SZ stand is a finned roll.
The pipe forming apparatus according to claim 12, wherein
A pipe forming apparatus in which each hole die in each swivel unit of the FP stand is a finned die in which a fin is provided at the center of the inner surface.
The pipe forming apparatus according to claim 12, wherein
A pipe forming apparatus in which fins are removed from the center of the inner surface of each hole die in each swivel unit of the FP stand, or a groove is provided in the center of the inner surface of each hole die to form the FP stand as a squeeze type.