WO2023243462A1

WO2023243462A1 - Welded tube manufacturing method and welded tube manufacturing apparatus

Info

Publication number: WO2023243462A1
Application number: PCT/JP2023/020822
Authority: WO
Inventors: 拓也齋藤; 武士物種; 洋次尾中; 泰作五明; 良太赤岩; 利幸吉川
Original assignee: 三菱電機株式会社
Priority date: 2022-06-13
Filing date: 2023-06-05
Publication date: 2023-12-21

Abstract

This welded tube manufacturing method comprises a step for fabricating a welded tube. In the step for fabricating a welded tube, a band-shaped metal plate (2) having a first end face and a second end face on the opposite side to the first end face in the width direction thereof is curved in the width direction into a tubular form, thereby forming a tubular body (3) with the first end face and the second end face facing each other, and then the first end face and the second end face are welded together by impinging an electronic beam thereon, thereby fabricating a welded tube.

Description

Welded pipe manufacturing method and welded pipe manufacturing device

The present disclosure relates to a welded pipe manufacturing method and a welded pipe manufacturing apparatus.

A welded pipe is manufactured by bending a band-shaped metal plate into a tubular shape in the width direction, and welding both ends in the width direction together. In such a welded pipe, if the welded portion becomes oxidized, the strength of the welded pipe itself will decrease. Therefore, a method for manufacturing a welded pipe that suppresses oxidation of the welded portion has been developed.

For example, in Patent Document 1, a band-shaped metal plate is curved in the width direction, and the joined ends are welded while supplying shielding gas to the internal space of a tubular body formed by bringing together both ends in the width direction. A method for manufacturing a welded pipe is disclosed.

Japanese Patent Application Publication No. 2000-271790

In the welded pipe manufacturing method described in Patent Document 1, an inert gas is used as the shielding gas. The inert gas is a special gas. Therefore, preparation of shielding gas and welding work are not easy.

The present disclosure has been made to solve the above problems, and aims to provide a welded pipe manufacturing method and a welded pipe manufacturing apparatus that can suppress oxidation of a welded part without using an inert gas.

In order to achieve the above object, a welded pipe manufacturing method according to the present disclosure is provided by forming a welded pipe by bending a band-shaped metal plate into a tubular shape in the width direction, and forming a welded pipe with a first end face in the width direction of the band-shaped metal plate and a first A welded tube is formed by colliding an electron beam with the first end surface and second end surface of the tubular body, which are opposite to each other, and welding the first end surface and the second end surface to each other. A manufacturing process is provided.

According to the configuration of the present disclosure, in the process of manufacturing a welded pipe, an electron beam collides with the first end face and second end face of the tubular body to weld the first end face and the second end face to each other. Create. As a result, the welded portion where the first end surface and the second end surface are welded together is less likely to be oxidized. According to the configuration of the present disclosure, oxidation of the welded portion can be suppressed without using an inert gas.

A side view of the first half of a welded pipe manufacturing apparatus according to an embodiment of the present disclosure Side view of the latter half of the welded pipe manufacturing apparatus according to the embodiment of the present disclosure A top view showing an example of a band-shaped metal plate formed by a stamping machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure. A top view showing another example of a band-shaped metal plate formed by the stamping machine included in the welded pipe manufacturing apparatus according to the embodiment of the present disclosure. A top view showing still another example of a band-shaped metal plate formed by a stamping machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure. A sectional view of a forming machine and a welding machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure A sectional view of a breakdown roll included in a forming machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure, and a band-shaped metal plate formed by the breakdown roll. A sectional view of a breakdown roll included in a forming machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure, and a band-shaped metal plate formed by the breakdown roll. A sectional view of a breakdown roll included in a forming machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure, and a band-shaped metal plate formed by the breakdown roll. A sectional view of a fin pass roll included in a forming machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure, and a band-shaped metal plate formed by the fin pass roll. A sectional view of a fin pass roll included in a forming machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure, and a band-shaped metal plate formed by the fin pass roll. A cross-sectional view of a tubular body finally formed by a forming machine included in a welded pipe manufacturing apparatus according to an embodiment of the present disclosure. A sectional view of a modified example of a forming machine and a welding machine included in the welded pipe manufacturing apparatus according to the embodiment of the present disclosure A sectional view of another modification of the forming machine and welding machine included in the welded pipe manufacturing apparatus according to the embodiment of the present disclosure A sectional view of still another modification of the forming machine and welding machine included in the welded pipe manufacturing apparatus according to the embodiment of the present disclosure A sectional view of a modification of the welded pipe manufacturing apparatus according to the embodiment of the present disclosure

Hereinafter, a welded pipe manufacturing method and a welded pipe manufacturing apparatus according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In addition, in the figures, the same or equivalent parts are given the same reference numerals. In addition, in the orthogonal coordinate system XYZ shown in the figure, when the upstream and downstream directions of the welded pipe manufacturing equipment are oriented horizontally, the vertical direction is the Z axis, and the upstream and downstream directions of the horizontal direction are the X axis. , the direction perpendicular to the Z-axis and the X-axis is the Y-axis.

(Embodiment)
The welded pipe manufacturing apparatus according to the embodiment is an apparatus for manufacturing a welded pipe from a band-shaped metal plate. This manufacturing apparatus manufactures a welded pipe by welding the joints of a tubular body formed by curving a band-shaped metal plate into a tubular shape in the width direction. The welding is performed in a vacuum by applying an electron beam to the joint in order to suppress oxidation of the weld. The configuration of this manufacturing apparatus will be described below, taking as an example a case where the welded tube to be manufactured is a heat exchanger tube used in a heat exchanger. First, the overall configuration of this manufacturing apparatus will be described with reference to FIGS. 1, 2, 3A, 3B, and 3C.

FIG. 1 is a side view of the first half of a welded pipe manufacturing apparatus 1 according to an embodiment. FIG. 2 is a side view of the latter half of the manufacturing apparatus 1.

As shown in FIGS. 1 and 2, the welded pipe manufacturing apparatus 1 includes an uncoiler 10, a connecting machine 11, an accumulator 12,

stamping machines

13 and 14, a forming machine 15, a welding machine 16, a drawing machine 17, and a cutting machine 18. and a recoiler 19.

A belt-shaped metal plate wound into a coil is supplied to the welded pipe manufacturing apparatus 1. The manufacturing apparatus 1 then manufactures a welded pipe from the band-shaped metal plate. The uncoiler 10 shown in FIG. 1 unwinds the coil around which the band-shaped metal plate is wound, and pulls out one end side of the band-shaped metal plate from the coil.

Specifically, the uncoiler 10 includes a cylindrical holder 111 that holds a coil of a band-shaped metal plate from the inside, and a drive unit (not shown) that rotates the holder 111. In the uncoiler 10, a drive unit (not shown) rotates the holder 111 in a direction opposite to the coil winding direction. Thereby, the uncoiler 10 pulls out one end side of the band-shaped metal plate from the coil. The uncoiler 10 supplies one end of the pulled out strip-shaped metal plate to the connecting machine 11 .

The connector 11 connects the other end of the strip-shaped metal plate and one end of another strip-shaped metal plate. Specifically, although not shown in the drawings, in the uncoiler 10, when the strip metal plate is completely pulled out from the coil, the next coil is set, and one end side of the strip metal plate is pulled out from the next coil. The connecting device 11 connects the other end of the previous coil on the opposite side to one end of the strip-shaped metal plate and one end of the pulled-out strip-shaped metal plate of the next coil.

To explain its configuration, the connecting machine 11 has a welding machine (not shown). The connecting machine 11 uses its welding machine to weld the other end of the band-shaped metal plate of the previous coil to one end of the band-shaped metal plate of the next coil. Note that the connecting machine is also referred to as strip joining.

On the other hand, the accumulator 12 stores a certain length of the band-shaped metal plate pulled out from the coil. Specifically, the accumulator 12 includes a roller (not shown). On the roller is hung the middle part of the strip-shaped metal plate drawn out from the coil. In order to prevent the supply of the strip metal plate from being stopped while welding is being performed by the splicing machine 11, the roller should be used to feed the intermediate portion of the strip metal plate during the welding time of the splicing machine 11. Roll it up to a certain length. Thereby, the accumulator 12 retains the band-shaped metal plate for a certain length. After the accumulator 12 winds up the middle part of the band-shaped metal plate by a certain length, the one end side part of the band-shaped metal plate, that is, the +X end part in the orthogonal coordinate system XYZ shown in FIG. send to.

The

stamping machines

13 and 14 are used to form grooves on the inner wall of the welded tube to be manufactured, specifically, to form grooves on the inner wall to improve heat exchange performance when the welded tube is used as a heat transfer tube. , is the part where grooves are formed in the band-shaped metal plate.

In detail, although not shown, the

engraving machines

13 and 14 include a first roll called a groove roll or a G roll with grooves formed on the outer periphery, and a first roll with grooves formed on the outer periphery without unevenness on the outer periphery. and a second roll having a smooth curved surface. Then, the engraving machine 13 inserts the band-shaped metal plate sent from the accumulator 12 and whose tension has been adjusted by the dancer rolls 131 and 132 shown in FIG. 1 between the first roll and the second roll described above. The stamping machine 13 passes the belt-shaped metal plate between the first roll and the second roll in a state where the first roll and the second roll are pressed against the belt-shaped metal plate. Thereby, the engraving machine 13 forms a groove on the band-shaped metal plate.

On the other hand, the engraving machine 14 has a third roll in which grooves of a different shape from the grooves of the first roll are formed on the outer periphery, and a curved surface with a smooth outer periphery without any unevenness on the outer periphery. and a fourth roll. The stamping machine 14 sandwiches the band-shaped metal plate, on which grooves have been formed by the stamping machine 13 and whose tension has been adjusted by dancer rolls 132 and 133, between the third roll and the fourth roll. Further, the stamping machine 14 presses the third roll and the fourth roll against the band-shaped metal plate. Furthermore, the stamping machine 14 passes the band-shaped metal plate between the third roll and the fourth roll. As a result, the stamping machine 14 forms a groove different from that in the case of the stamping machine 13 on the band-shaped metal plate.

The

engraving machines

13 and 14 form a plurality of grooves with different shapes in the metal band plate by performing the above-described processing on the metal band plate. Examples of band-shaped metal plates in which such grooves are formed are shown in FIGS. 3A, 3B, and 3C.

FIG. 3A is a top view showing an example of a band-shaped metal plate 2 formed by the

stamping machines

13 and 14 included in the welded pipe manufacturing apparatus 1. FIG. 3B is a top view showing another example of the band-shaped metal plate 2. FIG. 3C is a top view showing still another example of the band-shaped metal plate 2.

For example, as shown in FIG. 3A, the

engraving machines

13 and 14 form a herringbone-shaped groove in the band-shaped metal plate 2, in which a plurality of V-shaped grooves are arranged in the extending direction of the band of the band-shaped metal plate 2. do. Alternatively, the

engraving machines

13 and 14 form a plurality of X-shaped intersecting grooves on the band-shaped metal plate 2, as shown in FIG. 3B. Alternatively, the

stamping machines

13 and 14 form grooves that are inclined with respect to the extending direction of the band of the band-shaped metal plate 2 and embossments that are circular in top view on the band-shaped metal plate 2, as shown in FIG. 3C. The

stamping machines

13 and 14 improve the heat exchange efficiency of the welded tube by forming such grooves on the band-shaped metal plate 2 when the manufactured welded tube is used as a heat exchanger tube of a heat exchanger. enhance After the

stamping machines

13 and 14 form such grooves on the band-shaped metal plate 2, they send the grooved portions to a forming machine 15 and a welding machine 16 shown in FIG.

The detailed configuration of the forming machine 15 and the welding machine 16 will be described later, but to briefly explain their functions, the forming machine 15 bends the band-shaped metal plate 2 in the width direction of the band into a tubular shape, for example, a circular tube shape. Then, a tubular body having a shape that combines both ends of the band-shaped metal plate 2 in the width direction, that is, the +Y end and the -Y end, is formed. Specifically, the molding machine 15 includes a breakdown roll and a fin pass roll, which will be described later. Then, the forming machine 15 uses these rolls to form a tubular body on the +X end side of the band-shaped metal plate 2, with the +Y end and the -Y end aligned.

On the other hand, the welding machine 16 welds the seam of the tubular body described above. The welding machine 16 includes an electron beam welding machine to be described later, and uses the electron beam welding machine to weld the seam of the tubular body to produce a welded pipe portion on the +X end side of the band-shaped metal plate 2. Then, the welding machine 16 sends the welded pipe portion of the band-shaped metal plate 2 to the drawing machine 17.

The drawing machine 17 adjusts the size of the outer diameter and inner diameter of the welded pipe portion produced by the welding machine 16. Although not shown, the drawing machine 17 includes a die provided with a through hole that is smaller in outer diameter than the welded pipe produced by the welding machine 16 and has the same diameter as the target outer diameter. Then, the drawing machine 17 passes the welded pipe portion of the strip metal plate 2 through the die and pulls out the welded pipe portion from the die. Thereby, the drawing machine 17 processes the welded pipe portion of the strip metal plate 2 to have the same outer diameter as the diameter of the through hole of the die. The drawing machine 17 sends the processed welded pipe portion of the band-shaped metal plate 2 to the cutting machine 18 shown in FIG.

The cutting machine 18 includes a cutter 181 that is movable from the front to the back in FIG. 2, that is, in the Y direction. Then, the cutting machine 18 moves the cutter 181 to cut the welded pipe portion of the band-shaped metal plate 2 processed by the drawing machine 17 to a desired length. Thereby, the cutting machine 18 produces a welded pipe of a desired length. Then, the cutting machine 18 sends the welded pipe made to the desired length to the recoiler 19.

The recoiler 19 has a cylindrical winding section 191, and the welded tube cut to a desired length by the cutting machine 18 is wound up into the winding section 191 and re-coiled. Thereby, the recoiler 19 puts the produced welded pipe into a state where it can be supplied to an external device.

Note that the coiled band-shaped metal plate 2 mounted on the uncoiler 10 is, for example, a plate of rolled copper or copper alloy. In that case, the heat treatment is preferably O material, 1/2H material, or 1/4H material compliant with JIS H3100. Further, the width of the band-shaped metal plate 2 is preferably a size corresponding to the outer diameter of the welded pipe before being reduced in diameter by the drawing machine 17. For example, if the outer diameter of the welded pipe before being reduced by the drawing machine 17 is 7 mm, the width of the band-shaped metal plate 2 is determined by adding a welding margin of 0.5 mm to the circumference determined from the outer diameter. It is 5mm. Assuming that the thickness of the band-shaped metal plate 2 is reduced by 0.05 mm by the stamping machine 14, it is preferable that the thickness of the band-shaped metal plate 2 is 0.05 mm thicker than the thickness of the welded pipe before being reduced in diameter by the drawing machine 17.

In this manner, in the welded pipe manufacturing apparatus 1, the uncoiler 10 pulls out the band-shaped metal plate 2 wound into a coil, and the

stamping machines

13 and 14 form grooves in the band-shaped metal plate 2. Further, the forming machine 15 bends the band-shaped metal plate 2 into a tubular shape in the Y direction, and aligns the +Y end and the -Y end of the band-shaped metal plate 2. Then, the welding machine 16 welds the seam formed by matching the +Y end and the -Y end of the band-shaped metal plate 2 to produce a welded pipe.

At this time, a general welding device such as high frequency induction heating welding or TIG (Tungsten insert gas) welding is used as the welding machine 16, and the atmosphere when welding with that device contains a lot of oxygen. , the weld that is formed will be oxidized. In that case, the strength of the manufactured welded pipe will decrease.

On the other hand, in order to suppress oxidation of the welded part, a nozzle is installed in the high-frequency induction welding or TIG welding equipment, and an inert gas shielding gas such as argon gas or helium gas is sometimes supplied from the nozzle. . However, in this case, since the inert gas is a special gas, preparation of the inert gas and work using the inert gas are not easy. Further, as a result of providing gas supply equipment, the device structure becomes complicated and the device settings are complicated.

Therefore, in the welded pipe manufacturing apparatus 1, in order to suppress oxidation of the welded portion, the forming machine 15 and the welding machine 16 are provided with a vacuum chamber, and forming and welding are performed within the vacuum chamber. Next, the configurations of the forming machine 15 and the welding machine 16 will be described with reference to FIGS. 4, 5A to 5C, and 6A to 6C.

FIG. 4 is a sectional view of a forming machine 15 and a welding machine 16 included in the welded pipe manufacturing apparatus 1. 5A to 5C are sectional views of the breakdown rolls 30-35 of the forming machine 15 and the belt-shaped metal plate 2 formed by the breakdown rolls 30-35. 6A and 6B are cross-sectional views of the fin pass rolls 36-39 of the forming machine 15 and the band-shaped metal plate 2 formed by the fin pass rolls 36-39. FIG. 6C is a cross-sectional view of the tubular body 3 finally molded by the molding machine 15.

Although not shown in FIGS. 5A to 5C, 6A, and 6B, the plate surface of the band-shaped metal plate 2 on which the grooves are formed by the

stamping machines

13 and 14 is directed upward, that is, toward the +Z side. It is being

As shown in FIG. 4, the welded pipe manufacturing apparatus 1 includes vacuum chambers 20-22, breakdown rolls 30-35 and fin pass rolls 36-39 provided in the vacuum chamber 21, and the upper part of the vacuum chamber 21. The vacuum chamber 40 is provided with a vacuum chamber 40, and an electron beam welder 41 is provided within the vacuum chamber 40.

Note that the vacuum chamber 20-22, breakdown rolls 30-35, and fin pass rolls 36-39 are members that constitute the molding machine 15. On the other hand, the vacuum chamber 40 and the electron beam welder 41 are members that constitute the welder 16.

The vacuum chambers 20-22 are rooms provided to maintain a vacuum level that allows electron beam welding. Specifically, the vacuum chambers 20-22 are arranged in the order of

vacuum chambers

20, 21, and 22 from the upstream side of the welded tube manufacturing apparatus 1, that is, from the −X side. The vacuum chambers 20-22 are adjacent to each other in the X direction. Further, the

vacuum chambers

20 and 22 on both sides in the X direction are provided with transport rolls 23 and 24 for transporting the strip metal plate 2 to be processed and the welded pipe portion of the strip metal plate 2 after processing. . Further, the vacuum chamber 21 located at the center in the X direction accommodates a breakdown roll 30-35 and a fin pass roll 36-39 for forming the tubular body 3 to be welded from the strip metal plate 2 to be processed. Further, a vacuum chamber 40 that accommodates an electron beam welding machine 41 is connected to the vacuum chamber 21. As a result, inside the vacuum chamber 21, forming and welding, which are the manufacturing steps of a welded tube, are possible.

Note that the vacuum chamber 21 preferably has a larger volume than the

vacuum chambers

20 and 22 in order to form and weld the strip metal plate 2 to be processed.

In the vacuum chambers 20-22, in order to increase the degree of vacuum in the vacuum chamber 21 located at the center in the X direction, although not shown, the vacuum chamber 21 has a higher ultimate degree of vacuum than the vacuum pump that evacuates the

vacuum chambers

20 and 22. It is evacuated using a vacuum pump.

Specifically, each of the vacuum chambers 20-22 has an exhaust port (not shown) formed therein, and a vacuum pump (not shown) is connected to each of the exhaust ports. Among these vacuum pumps (not shown), the vacuum pumps connected to the exhaust ports of the

vacuum chambers

20 and 22 are for low vacuum. For example, the vacuum pump for low vacuum is a mechanical pump such as a water jet pump, reciprocating type, rotary type, or centrifugal type. On the other hand, the vacuum pump connected to the exhaust port of the vacuum chamber 21 is for medium vacuum, such as a mechanical booster or a turbo molecular pump. By connecting such a vacuum pump to the vacuum chambers 20-22, a structure is realized in which the vacuum chamber 21 with a high degree of vacuum is sandwiched between the

vacuum chambers

20 and 22 with a low degree of vacuum from both sides in the X direction. . For example, a structure is realized in which a vacuum chamber 21 of 2.0 to 6.0 Pa is sandwiched between

vacuum chambers

20 and 22 of 50 to 800 Pa.

Note that medium vacuum refers to a degree of vacuum that falls under one of the vacuum categories defined by Japanese Industrial Standards, and refers to a degree of vacuum of 0.1 to 100 Pa. Low vacuum refers to a degree of vacuum that falls under another category of vacuum defined by the same standard, and refers to a degree of vacuum of 100,000 to 100 Pa. In this specification, the term "in a vacuum" refers to a low vacuum or a vacuum with a higher degree of vacuum than a low vacuum. Furthermore, although the

vacuum chambers

20 and 22 have the same low vacuum, the same degree of vacuum here means that they are in the same vacuum category as described above.

Further, the vacuum chamber 20 is provided with an inlet 201 and an outlet 202, as shown in FIG. 4, in order to supply and discharge the strip metal plate 2 to be processed. The YZ cross-sectional shapes of the inlet 201 and the outlet 202 are larger than the YZ cross-sectional shape of the band-shaped metal plate 2 to the extent that they have play. A band-shaped metal plate 2 is passed through the inlet 201 and the outlet 202. As a result, gaps 205 and 206 are formed between the inner walls of the inlet 201 and the outlet 202 and the strip metal plate 2, which are small enough to allow the strip metal plate 2 to slide. Further, the flow of air from the outside into the vacuum chamber 20 is small, and as a result, a decrease in the degree of vacuum in the vacuum chamber 20 is suppressed.

Similarly, the vacuum chamber 21 is provided with an inlet 211 having the same shape and size as the outlet 202 of the vacuum chamber 20 in order to supply the strip metal plate 2 to be processed. Further, the inlet 211 is adjacent to and continuous with the outlet 202 in the X direction. As a result, inlet 211 is in communication with vacuum chamber 20 . Further, a band-shaped metal plate 2 is passed through the entrance 211. As a result, a minute gap 215 is formed between the inner wall of the inlet 211 and the strip metal plate 2 to the extent that the strip metal plate 2 can be slid, and a decrease in the degree of vacuum in the vacuum chamber 21 is suppressed. There is. In particular, since the inlet 211 communicates with the low vacuum vacuum chamber 20 in the -X direction, the degree of vacuum in the vacuum chamber 21 is less likely to decrease compared to the case where the inlet 211 is directly connected to the external space.

In addition, since the welded pipe portion 4 of the band-shaped metal plate 2 formed and welded in the vacuum chamber 21 is discharged into the vacuum chamber 21, the YZ cross-sectional shape has more play than the YZ cross-sectional shape of the welded pipe portion 4. An outlet 212 is provided which is large enough to have a diameter. A welded pipe portion 4 formed on one end side of the band-shaped metal plate 2, that is, formed on the +X end side, is passed through the outlet 212. As a result, a minute gap 216 is formed between the inner wall of the outlet 212 and the welded pipe part 4 to the extent that the welded pipe part 4 can slide, and a decrease in the degree of vacuum in the vacuum chamber 21 is suppressed. . Further, the outlet 212 communicates with a low vacuum chamber 22 via an inlet 221, which will be described later. This prevents the degree of vacuum in the vacuum chamber 21 from rapidly decreasing due to the outlet 212.

On the other hand, the vacuum chamber 22 is provided with an inlet 221 and an outlet 222 having the same shape and size as the outlet 212 of the vacuum chamber 21 in order to allow the welded pipe portion 4 to pass therethrough. The welded pipe portion 4 that has passed through the outlet 212 of the vacuum chamber 21 is passed through the inlet 221 and the outlet 222 . Due to these, minute gaps 225 and 226 are formed between the inner walls of the inlet 221 and the outlet 222 and the welded pipe portion 4 to the extent that the welded pipe portion 4 can be slid. Further, the flow of air from the outside into the vacuum chamber 22 is small, and a decrease in the degree of vacuum in the vacuum chamber 22 is suppressed. Further, the inlet 221 is adjacent to and continuous with the outlet 212 of the vacuum chamber 21 in the X direction. As a result, the degree of vacuum in the adjacent vacuum chamber 21 is less likely to decrease compared to the case where it is directly connected to the external space.

Note that the welded pipe portion 4 has a space at the center of the pipe. Therefore, air from outside the apparatus may flow into the

vacuum chambers

21 and 22 through the inside of the welded tube section 4. Therefore, before operating the welded pipe manufacturing apparatus 1 to manufacture welded pipes, special settings are made to pass the strip metal plate 2 to be processed through the vacuum chambers 20-22. In this special setting, a welded pipe portion 4 is prepared on the +X end side of the band-shaped metal plate 2, and the +X end of the welded pipe portion 4 is sealed. For example, a device for crushing the end of the tube is provided in the vacuum chamber 21 in an area on the +X side of the area where the electron beam is applied to the tubular body 3, which will be described later, or in the vacuum chamber 22, and the device is used for welding. Crush the +X end of tube section 4. This prevents the degree of vacuum in the

vacuum chambers

21 and 22 from decreasing through the internal space of the welded pipe portion 4. Note that the crushed +X end of the welded pipe portion 4 cannot be used as a welded pipe. For this reason, the +X end is preferably removed by the cutting machine 18 described above.

The degree of vacuum is maintained in the vacuum chamber 20-22 by providing

such inlets

201, 211, 221 and

outlets

202, 212, 222. Further, the vacuum chamber 21 located at the center in the X direction has a higher degree of vacuum than the

vacuum chambers

20 and 22 located on both sides of the vacuum chamber 21 in the X direction, and the vacuum chamber 21 is maintained at a degree of vacuum that allows electron beam welding. In order to form the strip metal plate 2 into a weldable shape in the vacuum chamber 21, the vacuum chamber 21 is provided with breakdown rolls 30-35 and fin pass rolls 36-39, as described above. .

As shown in FIGS. 5A to 5C, the breakdown rolls 30-35 are arranged above or below, and the strip metal plate 2 is passed between them, thereby making the strip metal plate 2 arc-shaped in cross-sectional view. Roughly shape.

Specifically, the breakdown rolls 30-35 are arranged in the order of breakdown rolls 30 and 31, 32 and 33, and 34 and 35 from the upstream side, that is, from the −X side as shown in FIG. As shown in FIGS. 5A to 5C, the breakdown roll 30 having a convex portion 301 that protrudes downward, that is, protruding toward the −Z side, and the breakdown roll 31 having a concave portion 311 recessed toward the −Z side are They are arranged in the direction and form pairs. Further, a breakdown roll 32 having a protrusion 321 protruding toward the -Z side and a breakdown roll 33 having a recess 331 concave toward the -Z side are arranged in the Z direction and form a pair. Further, a breakdown roll 34 having a convex portion 341 protruding toward the −Z side and a breakdown roll 35 having a concave portion 351 concave toward the −Z side are arranged in the Z direction to form a pair.

Further, in the breakdown rolls 30, 32, and 34, the heights of the

convex portions

301, 321, and 341 in the Z direction are arranged in the order of the

convex portions

301, 321, and 341, in other words, toward the downstream side, that is, toward the +X side. They are higher in order. On the other hand, the widths of the

convex portions

301, 321, and 341 in the Y direction become narrower in the same order. The YZ cross-sectional shapes of the tips of the

convex portions

301, 321, and 341 are rounded more in the same order.

On the other hand, in the breakdown rolls 31, 33, 35, the depth of the

recesses

311, 331, 351 in the Z direction becomes deeper in the order in which the breakdown rolls 31, 33, 35 are arranged toward the +X side. ing. On the other hand, the widths of the

recesses

311, 331, and 351 in the Y direction become narrower in the same order. The YZ cross-sectional shapes of the

recesses

311, 331, and 351 are more curved in the same order, approaching an arc shape.

By having such a shape, the breakdown rolls 30-35 curve the band-shaped metal plate 2 more toward the +X side. As a result, the breakdown rolls 30-35 are roughly formed into the shape of an arc in the YZ cross-sectional view shown in FIGS. 5A to 5C. Note that the plate surface of the band-shaped metal plate 2 on which the grooves are formed faces inside the arc in the YZ cross-sectional view.

On the other hand, as shown in FIGS. 6A and 6B, the fin pass rolls 36-39 are arranged in the Z direction in the same way as the breakdown rolls 30-35 and form a pair, but Unlike the case, the band-shaped metal plate 2 is passed between the pair of rolls, thereby finishing the band-shaped metal plate 2 into a circular shape in YZ cross-sectional view.

In detail, the fin pass rolls 36-39 are arranged in the order of fin pass rolls 36 and 37, and 38 and 39 from the -X side, as shown in FIG. As shown in FIGS. 6A and 6B, the fin pass roll 36 has a fin portion 361 formed in a recess that is arcuate in cross section and protrudes triangularly in cross section toward −Z side toward +Z side, and −Z side. Fin pass rolls 37 each having a recess formed in an arcuate shape when viewed in cross section are arranged in the Z direction and form a pair. In addition, a fin pass roll 38 in which a fin portion 381 protruding triangularly in cross-section toward the -Z side is formed in a recess that is recessed in an arc shape in cross section toward the +Z side, and a recess that is recessed in an arc shape in cross section toward the −Z side is formed. The formed fin path rolls 39 are arranged in the Z direction and form pairs.

Furthermore, in the fin path rolls 36 and 38, the width in the Y direction and the height in the Z direction of the

fin parts

361 and 381 are arranged in the order of the

fin parts

361 and 381, in other words, toward the downstream side, that is, toward the +X side. They are decreasing in order of size. The recesses of the fin pass rolls 36 and 38 and the recesses of the fin pass rolls 37 and 39 face each other in the Z direction and form a circular space in cross-section.

By having such a shape, the fin pass rolls 36-39 finish the band-shaped metal plate 2 into a circular shape in a YZ cross-sectional view, with the +Y end and -Y end of the band-shaped metal plate 2 approaching toward the +X side. Shape. Finally, the fin pass rolls 36-39 do not have a shape in which the +Y ends and -Y ends of the strip metal plate 2 face each other in a V-shape, as indicated by the dotted line in FIG. A tubular body 3 is formed having a seam 5 in a shape where both ends of the band-shaped metal plate 2 face each other as shown by the solid line in FIG. 6C, instead of facing each other in a V-shape. Note that in the molded tubular body 3, the grooved surface of the band-shaped metal plate 2 is oriented inward, so that the inner wall is provided with grooves.

Returning to FIG. 4, an electron beam welding machine 41 is installed on the fin pass rolls 38 and 39 in the vacuum chamber 21 in order to weld the joint 5 of the tubular body 3 formed by the fin pass rolls 36-39. A vacuum chamber 40 is provided.

A communication hole 42 is formed in the lower surface of the vacuum chamber 40 and is continuous with the through hole 25 in the upper surface of the vacuum chamber 21 . An electron beam welder 41 is disposed inside the vacuum chamber 40 and above the communication hole 42 .

Although not shown, the electron beam welding machine 41 includes a cathode part to which a voltage is applied to generate an electron beam, an anode part to accelerate the electron beam, and an electron lens part to converge or deflect the electron beam. Then, the electron beam welding machine 41 emits an electron beam generated by the cathode section toward the communication hole 42 and the through hole 25 described above, and directs the electron beam to the seam 5 of the tubular body 3 of the vacuum chamber 21. guess. Thereby, the electron beam welding machine 41 welds the seam 5 of the tubular body 3 to produce the welded pipe portion 4.

At this time, since the inside of the vacuum chamber 21 is in a vacuum state, almost no oxygen exists. As a result, in the welded tube manufacturing apparatus 1, the welded portion formed at the seam 5 of the tubular body 3 to which the electron beam is applied is unlikely to oxidize. As a result, the strength of the welded pipe manufactured is high.

Note that both ends of the band-shaped metal plate 2 described above, in other words, the +Y end and the -Y end of the band-shaped metal plate 2 are examples of the first end face and the second end face in the width direction of the band-shaped metal plate 2 in the present disclosure. be. Further, the portion formed or welded on the +X side of the band-shaped metal plate 2 is an example of the first portion on one end side in the present disclosure.

Furthermore, the vacuum chamber 21 and the inlet 211 and outlet 212 of the vacuum chamber 21 described above are examples of the first vacuum chamber, the first inlet, and the first outlet in the present disclosure. Further, the vacuum chamber 20 and the inlet 201 and outlet 202 of the vacuum chamber 20 are examples of a second vacuum chamber, a second inlet, and a second outlet as referred to in the present disclosure. The vacuum chamber 22 and the inlet 221 and outlet 222 of the vacuum chamber 22 are examples of a third vacuum chamber, a third inlet, and a third outlet as referred to in the present disclosure. Furthermore, the gaps 205, 206, and 215 are examples of first gaps referred to in the present disclosure. The gaps 216, 225, and 226 are examples of second gaps referred to in the present disclosure.

The transport rolls 23 and 24 described above are an example of a feeding mechanism in the present disclosure. The conveyance rolls 23 and 24 feeding the strip metal plate 2 is an example of the process of feeding the strip metal plate into the first vacuum chamber or the process of feeding the welded tube from the first vacuum chamber as referred to in the present disclosure. Further, the breakdown rolls 30-35 and the fin pass rolls 36-39 are examples of forming rolls as referred to in the present disclosure.

Furthermore, the formation of grooves on the band-shaped metal plate 2 by the above-mentioned

stamping machines

13 and 14 is an example of the process of forming grooves in the present disclosure. The first roll, second roll, third roll, and fourth roll provided in the

stamping machines

13 and 14 are examples of groove forming rolls as referred to in the present disclosure. Further, the forming of the tubular body 3 using the breakdown rolls 30-35 and the fin pass rolls 36-39 described above is an example of the process of forming a tubular body as referred to in the present disclosure. Further, the welding of the joint 5 of the tubular body 3 by the electron beam welder 41, that is, the welding process, is an example of the process of producing a welded pipe as referred to in the present disclosure.

Further, the various conditions of the electron beam welding machine 41 described above depend on the size and material of the welded tube to be manufactured, but for example, the rated output is 6 kW, the acceleration voltage is 40 kV, the electron beam current is 5 to 150 mA, and the cathode section is W. It is best to make it into a rod shape.

As described above, in the welded pipe manufacturing apparatus 1 according to the embodiment, the electron beam welding machine 41 performs welding by colliding electron beams in a vacuum. Therefore, the manufacturing apparatus 1 can suppress oxidation of the welded portion to be formed. As a result, the strength of the welded part is high, and the strength of the welded pipe manufactured is high.

Furthermore, in the welded pipe manufacturing apparatus 1, since the electron beam welder 41 performs welding in a vacuum, there is no need to use an inert gas. As a result, there is no need to prepare a special gas, so preparation and work for manufacturing welded pipes is easy.

In the welded pipe manufacturing apparatus 1, a vacuum chamber 20 having a lower degree of vacuum than the vacuum chamber 21 is adjacent to the entrance 211 of the vacuum chamber 21 where welding is performed. Then, after passing through the vacuum chamber 20, the one end portion of the strip metal plate 2 to be processed is fed into the vacuum chamber 21 from the inlet 211. Therefore, the degree of vacuum in the vacuum chamber 21 is unlikely to decrease, and it is easy to maintain a degree of vacuum that allows electron beam welding.

Similarly, in the welded tube manufacturing apparatus 1, a vacuum chamber 22 having a lower degree of vacuum than the vacuum chamber 21 is adjacent to the outlet 212 of the vacuum chamber 21. Then, the welded pipe portion 4 of the band-shaped metal plate 2 after processing is sent out from the outlet 212, after passing through the vacuum chamber 22. Therefore, the degree of vacuum in the vacuum chamber 21 is unlikely to decrease, and it is easy to maintain a degree of vacuum that allows electron beam welding.

Although the welded pipe manufacturing method and welded pipe manufacturing apparatus 1 according to the embodiment of the present disclosure have been described above, the welded pipe manufacturing method and welded pipe manufacturing apparatus 1 are not limited thereto.

(Modification 1)
In the first embodiment, only minute gaps 215 and 216 are provided between the inlet 211 and the outlet 212 of the vacuum chamber 21. However, the vacuum chamber 21 is not limited to this. Seals may be provided at the inlet 211 and outlet 212 of the vacuum chamber 21.

FIG. 7 is a sectional view of a modification of the forming machine and welding machine included in the welded pipe manufacturing apparatus 1.

As shown in FIG. 7, a seal 50 may be provided at the entrance 211 of the vacuum chamber 21 along the inner wall surface. Further, a seal 51 may be provided at the outlet 212 of the vacuum chamber 21 along the inner wall surface. This is because with such a configuration, the airtightness of the vacuum chamber 21 can be improved and the degree of vacuum in the vacuum chamber 21 can be easily maintained. Moreover, as a result, oxidation of the welded portion can be further suppressed.

In this case, although not shown, the

seals

50 and 51 are preferably frame-shaped or O-ring shaped. The

seals

50 and 51 are preferably made of a low-friction material, such as polytetrafluoroethylene, which is a fluororesin, in order to allow the band-shaped metal plate 2 or the welded pipe portion 4 to be taken in and out of the vacuum chamber 21. Note that the

seals

50 and 51 may be installed at the inlet 201 and outlet 202 of the vacuum chamber 20 and the inlet 221 and outlet 222 of the vacuum chamber 22 in the same arrangement as in the case of the vacuum chamber 21. In this case, it is preferable that the

seals

50 and 51 be installed in the vacuum chamber 21 having a high degree of vacuum in preference to the

vacuum chambers

20 and 22.

(Modification 2)
In the first embodiment, in order to prevent air from outside the device from flowing into the

vacuum chambers

21 and 22, the end of the welded pipe portion 4 formed at one end of the band-shaped metal plate 2 is sealed in advance. In this state, the welded pipe manufacturing apparatus 1 is operated to manufacture a welded pipe. However, the means for preventing air from flowing into the

vacuum chambers

21 and 22 is not limited to this. The welded pipe portion 4 of the strip metal plate 2 may be plugged.

FIG. 8 is a sectional view of another modification of the forming machine and welding machine included in the welded pipe manufacturing apparatus 1.

As shown in FIG. 8, a plug 60 may be provided in the internal space of the −X end portion of the welded pipe portion 4. Specifically, a small cylindrical plug 60 may be provided in the internal space of the portion immediately after the band-shaped metal plate 2 is formed into the tubular body 3 and welded by the electron beam welding machine 41. This is because with such a configuration, it is possible to prevent air from flowing in through the internal space of the welded pipe portion 4 of the band-shaped metal plate 2.

In this case, the plug 60 has one end fixed to the inner wall of the vacuum chamber 21 and the other end bent, parallel to the X direction, and inserted into the internal space of the welded pipe section 4 from the -X side. It is preferable that it is supported by a support rod 61. The plug 60 preferably has an outer diameter that allows it to be loosely inserted into the welded pipe section 4. Furthermore, the plug 60 is preferably made of a low-friction material, similar to the

seals

50 and 51 of the first modification.

(Modification 3)
In the embodiment, a measuring device is not provided in the vacuum chamber 20-22, but a measuring device may be provided in the vacuum chamber 20-22. Then, the welded pipe manufacturing apparatus 1 may operate based on the measurement results of the measuring device.

For example, the welded tube manufacturing apparatus 1 may include a vacuum gauge that is provided in the vacuum chamber 21 and measures the degree of vacuum within the vacuum chamber 21. Here, the vacuum gauge is, for example, a U-tube manometer or a diaphragm vacuum gauge. In the welded tube manufacturing apparatus 1, when a welding defect exists in the welded tube portion 4 of the tubular body 3 that is welded in the vacuum chamber 21, the welded defective portion passes through the vacuum chamber 22 to the outside of the vacuum chamber 22. If air escapes, air may flow into the welded pipe section 4 from the location where the welding defect exists. In that case, the inflowing air enters the vacuum chamber 21 through the unwelded seam 5 of the tubular body 3, lowering the degree of vacuum in the vacuum chamber 21, and further oxidizing the welded portion. Therefore, a vacuum gauge may be provided in the vacuum chamber 21, and a control device, which will be described later and included in the welded pipe manufacturing apparatus 1, may determine the presence or absence of the above-mentioned welding defect based on pressure data measured by the vacuum gauge. If the control device determines that there is a welding defect, the manufacturing apparatus 1 may stop manufacturing the welded pipe. Further, if the control device determines that there is a welding defect, the welded pipe portion 4 which is exposed outside the vacuum chamber 22 at that time may be determined to be defective, or the inside of the vacuum chamber 21 where the degree of vacuum has decreased. The parts after welded pipe part 4 may be considered defective. In addition, in determining the presence or absence of a welding defect, if the pressure measured by the vacuum gauge is a gauge pressure, it is preferable to convert the gauge pressure into an absolute pressure. Then, when the value of the pressure measured by the vacuum gauge is larger than a threshold value, it may be determined that there is a welding defect.

Although an example has been described in which the vacuum gauge is provided in the vacuum chamber 21, the vacuum gauge may be provided in at least one of the vacuum chambers 20-22.

(Modification 4)
The vacuum gauge described above may be replaced by other vacuum measuring instruments. For example, a vacuum gauge may be replaced with an optical leak detector.

FIG. 9 is a sectional view of yet another modification of the forming machine and welding machine included in the welded pipe manufacturing apparatus 1.

As shown in FIG. 9, the welded pipe manufacturing apparatus 1 may include an optical leak detector 70 that is installed in the vacuum chamber 22 and measures the degree of vacuum within the vacuum chamber 22. Here, the optical leak detector 70 is arranged in a measurement environment, here, in a case communicating with the vacuum chamber 22, and has two electrodes that are provided with a potential difference and emit electrons; and an optical measuring device that measures the spectral intensity of light emitted when the electrons collide with gas atoms and molecules in the case, and the partial pressure of the gas can be determined from the spectral intensity measured by the optical measuring device. This refers to the device you are looking for. Note that the above two electrodes and the optical measuring device may be provided directly within the vacuum chamber 22 instead of within the above case.

The optical measuring instrument included in the optical leak detector 70 measures the spectral intensity of purple light when outside air flows into the vacuum chamber 22, as a result of the outside air containing a large amount of nitrogen. Alternatively, optical measuring instruments measure the spectral intensity of dim purple light depending on the concentration of oxygen in the outside air. Against this background, the optical leak detector 70 determines the pressure inside the vacuum chamber 22 by determining the pressure inside the case from the measured spectral intensity when outside air flows into the vacuum chamber 22. Good. Then, the control device 80 may determine the presence or absence of the above-mentioned welding defect from the pressure determined by the optical leak detector 70.

Note that the optical leak detector 70 is preferably provided in the

vacuum chamber

20 or 22 instead of the vacuum chamber 21. This is because if the optical leak detector 70 is provided in the vacuum chamber 21, the two electrodes included in the optical leak detector 70 may affect electron beam welding, and welding may not be performed at an appropriate location.

Further, the above-described control device 80 includes a CPU (Central Processing Unit) 81 and a memory 82, and the CPU 81 reads and executes a determination program stored in the memory 82, thereby performing the above-described process of determining the presence or absence of a welding defect. It's good to do.

Furthermore, in the embodiment, the welded pipe manufacturing apparatus 1 includes three vacuum chambers 20-22. However, the welded pipe manufacturing apparatus 1 is not limited to this. In the welded pipe manufacturing apparatus 1, the vacuum chamber 20-22 is formed by bending the band-shaped metal plate 2 into a tubular shape in the width direction, and the vacuum chamber 20-22 is formed by bending the band-shaped metal plate 2 into a tubular shape in the width direction, and the vacuum chamber 20-22 is formed by bending the band-shaped metal plate 2 into a tubular shape in the width direction. Any structure may be used as long as it accommodates a tubular body whose second end face on the opposite side faces each other. Then, inside the vacuum chamber 20-22, the electron beam welding machine 41 collides the electron beam with the first end surface and the second end surface of the tubular body to weld the first end surface and the second end surface to each other. It is enough to make a welded pipe. Therefore, the number of vacuum chambers 20-22 is arbitrary as long as these conditions are satisfied. For example, the welded pipe manufacturing apparatus 1 may include only one vacuum chamber 21. This is because even in this form, oxidation of the welded portion can be suppressed.

Furthermore, in the embodiment, a molding machine 15 and a welding machine 16 are housed in the vacuum chamber 20-22. However, the equipment accommodated in the vacuum chambers 20-22 is not limited to this. Since the electron beam welding machine 41 only needs to satisfy the above conditions and create the welded tube, other equipment for processing the band-shaped metal plate 2 may be housed in the vacuum chamber 20-22.

FIG. 10 is a sectional view of a modification of the welded pipe manufacturing apparatus 1 according to the embodiment.

As shown in FIG. 10, the

engraving machines

13, 14 and dancer rolls 131-133 described in the embodiment may be housed in the vacuum chamber 21. As a result, grooves are preferably formed in the band-shaped metal plate 2 in the vacuum chamber 21. In such a configuration, since the strip-shaped metal plate 2 having a flat plate surface without grooves is inserted from the entrance 211 of the vacuum chamber 21, the gap 215 at the entrance 211 is made small to reduce the vacuum in the vacuum chamber 21. This is because the degree can be lowered. This is also because it becomes easier to maintain the degree of vacuum in the vacuum chamber 21.

In the embodiment, the welded pipe manufacturing apparatus 1 includes an accumulator 12. However, the welded pipe manufacturing apparatus 1 is not limited to this. In the welded pipe manufacturing apparatus 1, the accumulator 12 has an arbitrary configuration. For example, if production efficiency may be reduced, the welded pipe manufacturing apparatus 1 may not include the accumulator 12.

In the embodiment, the welded pipe manufacturing apparatus 1 includes stamping

machines

13 and 14. However, the welded pipe manufacturing apparatus 1 is not limited to this. In the welded pipe manufacturing apparatus 1, the

engraving machines

13 and 14 have an arbitrary configuration. For example, when manufacturing a welded pipe without grooves, the welded pipe manufacturing apparatus 1 does not need to include the

engraving machines

13 and 14. Further, when manufacturing a welded pipe having a groove, the welded pipe manufacturing apparatus 1 only needs to include at least one stamping

machine

13, 14 in order to form the groove.

In the embodiment, the welded pipe manufacturing apparatus 1 does not include any machine or device after the recoiler 19. However, the welded pipe manufacturing apparatus 1 is not limited to this. The welded pipe manufacturing apparatus 1 may include an annealing device after the recoiler 19 in order to prevent the manufactured welded pipe from cracking during bending or expansion.

In the embodiment, the welded tube manufacturing apparatus 1 will be described using an example in which the welded tubes to be manufactured are heat exchanger tubes used in a heat exchanger. However, the welded pipe manufactured is not limited to this. The welded pipe manufacturing method and welded pipe manufacturing apparatus 1 according to the embodiments of the present disclosure are applicable to all welded pipes that require suppression of oxidation of the welded portion.

As described above, the welded pipe manufacturing method and welded pipe manufacturing apparatus 1 are not limited to the above embodiments, and various modifications and substitutions can be made. Various aspects of the present disclosure are described below as supplementary notes.

(Additional note 1)
A tubular shape formed by curving a band-shaped metal plate into a tubular shape in the width direction, and in which a first end face in the width direction of the band-shaped metal plate and a second end face opposite to the first end face face each other. producing a welded pipe by colliding an electron beam with the first end surface and the second end surface of the body to weld the first end surface and the second end surface to each other;
Method for manufacturing welded pipes.
(Additional note 2)
further comprising the step of forming the tubular body in a shape where the first end surface and the second end surface face each other by curving the band-shaped metal plate into a tubular shape in the width direction in a vacuum space,
In the step of producing the welded tube, the electron beam collides with the first end surface and the second end surface of the tubular body in the vacuum space to weld the first end surface and the second end surface to each other. ,
A method for manufacturing a welded pipe according to Supplementary Note 1.
(Additional note 3)
further comprising the step of feeding the band-shaped metal plate from one end side in the direction in which the band extends into the first vacuum chamber having the vacuum space,
In the step of forming the tubular body, the first portion on the one end side of the band-shaped metal plate is bent into a tubular shape in the width direction inside the first vacuum chamber, thereby forming the tubular body on the first portion. death,
In the step of producing the welded tube, the electron beam is made to collide with the first end surface and the second end surface of the tubular body formed in the first portion inside the first vacuum chamber to produce the welded tube. welding the one end surface and the second end surface to each other;
The method for manufacturing a welded pipe according to appendix 2.
(Additional note 4)
further comprising the step of forming grooves on the plate surface of the band-shaped metal plate in a vacuum space,
In the step of producing the welded pipe, the first end surface and the second end surface of the tubular body are formed by curving the band-shaped metal plate with the plate surface on which the grooves are formed facing inward. colliding the electron beam in the vacuum space to weld the first end surface and the second end surface to each other;
A method for manufacturing a welded pipe according to any one of Supplementary Notes 1 to 3.
(Appendix 5)
further comprising the step of feeding the band-shaped metal plate from one end side in the direction in which the band extends into the first vacuum chamber having the vacuum space,
In the step of forming the groove, forming the groove on the plate surface of the first portion on the one end side of the band-shaped metal plate inside the first vacuum chamber,
In the step of producing the welded pipe, the first portion of the band-shaped metal plate is bent with the plate surface on which the grooves are formed facing inward, thereby forming the tubular body formed in the first portion. Welding the first end surface and the second end surface to each other by colliding the electron beam with the first end surface and the second end surface inside the first vacuum chamber;
The method for manufacturing a welded pipe according to appendix 4.
(Appendix 6)
Further comprising the step of sending out the welded pipe produced in the first part from the first vacuum chamber,
A second vacuum chamber adjacent to the first vacuum chamber and having a lower degree of vacuum than the first vacuum chamber is provided on the side of the first vacuum chamber into which the one end side of the band-shaped metal plate is fed,
A third vacuum chamber adjacent to the first vacuum chamber and having a lower degree of vacuum than the first vacuum chamber is provided on the side of the first vacuum chamber from which the welded pipe is sent out,
In the step of feeding the band-shaped metal plate into the first vacuum chamber, feeding the band-shaped metal plate into the first vacuum chamber via the second vacuum chamber,
In the step of sending out the welded tube from the first vacuum chamber, sending out the welded tube from the first vacuum chamber to the outside via the third vacuum chamber,
The method for manufacturing a welded pipe according to

appendix

3 or 5.
(Appendix 7)
In the step of producing the welded pipe, one end of the welded pipe is sealed, and the internal space of the welded pipe is at the same vacuum as the inside of the first vacuum chamber.
The method for manufacturing a welded pipe according to any one of

Supplementary Notes

3, 5, and 6.
(Appendix 8)
In the step of producing the welded pipe, the degree of vacuum in the space in which the electron beam collides with the first end face and the second end face is measured using a vacuum gauge, and weld defects are detected based on the measured value of the degree of vacuum. including the step of determining the presence or absence of the
A method for manufacturing a welded pipe according to any one of Supplementary Notes 1 to 7.
(Appendix 9)
The step of producing the welded pipe includes causing electrons to collide with a gas in another space communicating with the space in which the electron beam collides with the first end face and the second end face, causing the gas to emit light, and adjusting the spectrum of the light. by measuring the pressure of the gas to determine the degree of vacuum of the space in which the electron beam collides, and determining the presence or absence of a welding defect based on the determined degree of vacuum.
A method for manufacturing a welded pipe according to any one of Supplementary Notes 1 to 7.
(Appendix 10)
A tubular shape formed by curving a band-shaped metal plate into a tubular shape in the width direction, and in which a first end face in the width direction of the band-shaped metal plate and a second end face opposite to the first end face face each other. a first vacuum chamber that accommodates the body;
A welded tube is produced by colliding an electron beam with the first end surface and the second end surface of the tubular body inside the first vacuum chamber to weld the first end surface and the second end surface to each other. An electron beam welding machine that
A welded pipe manufacturing device comprising:
(Appendix 11)
further comprising a feeding mechanism that feeds the band-shaped metal plate into the first vacuum chamber from one end in the direction in which the band extends,
The first vacuum chamber is
a first entrance into which the band-shaped metal plate is fed from the one end side;
By feeding the band-shaped metal plate from the one end side into the first inlet by the feeding mechanism, the second end surface is welded to the first end surface of the tubular body by the electron beam welding machine. a first outlet through which the welded pipe manufactured at the portion on the one end side is sent out;
has
In the first vacuum chamber, a portion on the one end side of the band-shaped metal plate fed into the first vacuum chamber from the first inlet by the feeding mechanism is inserted into the inner space in a tubular shape in the width direction. A forming roll that is curved and forms a tubular body having a shape in which the first end face and the second end face face each other is housed in a portion on the one end side.
The welded pipe manufacturing apparatus according to appendix 10.
(Appendix 12)
The first vacuum chamber accommodates in its internal space a groove forming roll that forms grooves on the plate surface of the strip-shaped metal plate fed into the first vacuum chamber from the first inlet by the feeding mechanism. is,
The forming roll forms the tubular body by curving the first portion of the band-shaped metal plate with the plate surface on which the grooves are formed facing inward.
The welded pipe manufacturing apparatus according to appendix 11.
(Appendix 13)
a second vacuum chamber adjacent to the first vacuum chamber on the side where the first inlet of the first vacuum chamber is located and having a lower degree of vacuum than the first vacuum chamber;
a third vacuum chamber adjacent to the first vacuum chamber on the side where the first outlet of the first vacuum chamber is located and having a lower degree of vacuum than the first vacuum chamber;
Furthermore,
The second vacuum chamber includes a second inlet into which the band-shaped metal plate is fed from the one end side by the feeding mechanism, and a second inlet into which the band-shaped metal plate is fed from the one end side by the feeding mechanism. a second outlet through which the band-shaped metal plate is sent out from the one end side, and the second outlet is connected to the first inlet, thereby communicating with the first vacuum chamber;
The third vacuum chamber includes a third inlet into which the welded pipe produced on the one end side of the band-shaped metal plate is fed from the first outlet by the feeding mechanism, and the feeding mechanism. and a third outlet through which the welded pipe is sent out by feeding the welded pipe made on the one end side of the band-shaped metal plate into the third inlet, A third inlet communicates with the first vacuum chamber by connecting with the first outlet;
The welded pipe manufacturing apparatus according to appendix 11 or 12.
(Appendix 14)
The first inlet, the second inlet, and the second outlet are a first gap in which the band-shaped metal plate can slide between the flat metal plate and the band-shaped metal plate with the band-shaped metal plate inserted therethrough. has
The first outlet, the third inlet, and the third outlet are connected to the welded tube between the welded tube and the welded tube, which is made in a portion on the one end side of the band-shaped metal plate, and is inserted therethrough. having a second gap in which the pipe can slide;
The welded pipe manufacturing apparatus according to appendix 13.
(Appendix 15)
one end of the welded tube outside the first vacuum chamber is sealed, and the internal space of the welded tube is at the same vacuum as the inside of the first vacuum chamber;
The welded pipe manufacturing apparatus according to any one of Supplementary Notes 10 to 14.
(Appendix 16)
a vacuum gauge that measures the degree of vacuum in the internal space of the first vacuum chamber;
a control device that determines the presence or absence of a welding defect in the welded pipe produced by the electron beam welding machine based on the measured value of the vacuum gauge;
further comprising,
The welded pipe manufacturing apparatus according to any one of appendices 10 to 15.
(Appendix 17)
Optics for determining the degree of vacuum in the internal space of the first vacuum chamber by measuring the spectrum of light emitted when electrons collide with the gas in the space communicating with the first vacuum chamber to determine the pressure of the gas. formula leak detector,
a control device that determines whether there is a welding defect in the welded pipe produced by the electron beam welding machine based on the degree of vacuum in the internal space determined by the optical leak detector;
further comprising;
The welded pipe manufacturing apparatus according to any one of appendices 10 to 15.

The present disclosure is capable of various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Further, the embodiments described above are for explaining the present disclosure, and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is indicated by the claims rather than the embodiments. Various modifications made within the scope of the claims and the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

This application is based on Japanese Patent Application No. 2022-95328 filed on June 13, 2022. The entire specification, claims, and drawings of Japanese Patent Application No. 2022-95328 are incorporated herein by reference.

1. Welded pipe manufacturing equipment, 2. Band-shaped metal plate, 3. Tubular body, 4. Welded pipe section, 5. Seam, 10. Uncoiler, 11. Connector, 12. Accumulator, 13, 14. Stamping machine, 15. Forming machine, 16. Welding machine. 17 drawing machine, 18 cutting machine, 19 recoiler, 20-22 vacuum chamber, 23, 24 conveyance roll, 25 through hole, 30-35 breakdown roll, 36-39 fin pass roll, 40 vacuum chamber, 41 electron beam welding machine , 42 communication hole, 50, 51 seal, 60 stopper, 61 support rod, 70 optical leak detector, 80 control device, 81 CPU, 82 memory, 111 holder, 131-133 dancer roll, 181 cutter, 191 winding section, 201 inlet, 202 outlet, 205, 206 gap, 211 inlet, 212 outlet, 215, 216 gap, 221 inlet, 222 outlet, 225, 226 gap, 301 convex part, 311 concave part, 321 convex part, 331 concave part, 341 Convex part , 351 recessed portion, 361, 381 fin portion.

Claims

A tubular shape formed by curving a band-shaped metal plate into a tubular shape in the width direction, and in which a first end face in the width direction of the band-shaped metal plate and a second end face opposite to the first end face face each other. producing a welded pipe by colliding an electron beam with the first end surface and the second end surface of the body to weld the first end surface and the second end surface to each other;
Method for manufacturing welded pipes.
further comprising the step of forming the tubular body in a shape where the first end surface and the second end surface face each other by curving the band-shaped metal plate into a tubular shape in the width direction in a vacuum space,
In the step of producing the welded tube, the electron beam collides with the first end surface and the second end surface of the tubular body in the vacuum space to weld the first end surface and the second end surface to each other. ,
The method for manufacturing a welded pipe according to claim 1.
further comprising the step of feeding the band-shaped metal plate from one end side in the direction in which the band extends into the first vacuum chamber having the vacuum space,
In the step of forming the tubular body, the first portion on the one end side of the band-shaped metal plate is bent into a tubular shape in the width direction inside the first vacuum chamber, thereby forming the tubular body on the first portion. death,
In the step of producing the welded tube, the electron beam is made to collide with the first end surface and the second end surface of the tubular body formed in the first portion inside the first vacuum chamber to produce the welded tube. welding the one end surface and the second end surface to each other;
The method for manufacturing a welded pipe according to claim 2.
further comprising the step of forming grooves on the plate surface of the band-shaped metal plate in a vacuum space,
In the step of producing the welded pipe, the first end surface and the second end surface of the tubular body are formed by curving the band-shaped metal plate with the plate surface on which the grooves are formed facing inward. colliding the electron beam in the vacuum space to weld the first end surface and the second end surface to each other;
The method for manufacturing a welded pipe according to any one of claims 1 to 3.
further comprising the step of feeding the band-shaped metal plate from one end side in the direction in which the band extends into the first vacuum chamber having the vacuum space,
In the step of forming the groove, forming the groove on the plate surface of the first portion on the one end side of the band-shaped metal plate inside the first vacuum chamber,
In the step of producing the welded pipe, the first portion of the band-shaped metal plate is bent with the plate surface on which the grooves are formed facing inward, thereby forming the tubular body formed in the first portion. Welding the first end surface and the second end surface to each other by colliding the electron beam with the first end surface and the second end surface inside the first vacuum chamber;
The method for manufacturing a welded pipe according to claim 4.
Further comprising the step of sending out the welded pipe produced in the first part from the first vacuum chamber,
A second vacuum chamber adjacent to the first vacuum chamber and having a lower degree of vacuum than the first vacuum chamber is provided on the side of the first vacuum chamber into which the one end side of the band-shaped metal plate is fed,
A third vacuum chamber adjacent to the first vacuum chamber and having a lower degree of vacuum than the first vacuum chamber is provided on the side of the first vacuum chamber from which the welded tube is sent out,
In the step of feeding the band-shaped metal plate into the first vacuum chamber, feeding the band-shaped metal plate into the first vacuum chamber via the second vacuum chamber,
In the step of sending the welded tube out of the first vacuum chamber, the welded tube is sent out from the first vacuum chamber via the third vacuum chamber.
The method for manufacturing a welded pipe according to claim 3 or 5.
In the step of producing the welded pipe, one end of the welded pipe is sealed, and the internal space of the welded pipe is at the same vacuum as the inside of the first vacuum chamber.
The method for manufacturing a welded pipe according to any one of claims 3, 5, and 6.
In the step of producing the welded pipe, the degree of vacuum in the space in which the electron beam collides with the first end face and the second end face is measured using a vacuum gauge, and weld defects are detected based on the measured value of the degree of vacuum. including the step of determining the presence or absence of the
The method for manufacturing a welded pipe according to any one of claims 1 to 7.
The step of producing the welded pipe includes causing electrons to collide with a gas in another space communicating with the space in which the electron beam collides with the first end face and the second end face, causing the gas to emit light, and adjusting the spectrum of the light. by measuring the pressure of the gas to determine the degree of vacuum of the space in which the electron beam collides, and determining the presence or absence of a welding defect based on the determined degree of vacuum.
The method for manufacturing a welded pipe according to any one of claims 1 to 7.
A tubular shape formed by curving a band-shaped metal plate into a tubular shape in the width direction, and in which a first end face in the width direction of the band-shaped metal plate and a second end face opposite to the first end face face each other. a first vacuum chamber that accommodates the body;
A welded tube is produced by colliding an electron beam with the first end surface and the second end surface of the tubular body inside the first vacuum chamber to weld the first end surface and the second end surface to each other. An electron beam welding machine that
A welded pipe manufacturing device comprising:
further comprising a feeding mechanism that feeds the band-shaped metal plate into the first vacuum chamber from one end in the direction in which the band extends,
The first vacuum chamber is
a first entrance into which the band-shaped metal plate is fed from the one end side;
By feeding the band-shaped metal plate from the one end side into the first inlet by the feeding mechanism, the second end surface is welded to the first end surface of the tubular body by the electron beam welding machine. a first outlet formed in the first portion on the one end side through which the welded pipe is sent out;
has
In the first vacuum chamber, the first portion of the band-shaped metal plate fed into the first vacuum chamber from the first inlet by the feeding mechanism is bent into a tubular shape in the width direction, into the internal space thereof, A forming roll for forming a tubular body having a shape in which the first end face and the second end face face each other is housed in the first part.
The welded pipe manufacturing apparatus according to claim 10.
The first vacuum chamber accommodates in its internal space a groove forming roll that forms grooves on the plate surface of the strip-shaped metal plate fed into the first vacuum chamber from the first inlet by the feeding mechanism. is,
The forming roll forms the tubular body by curving the first portion of the band-shaped metal plate with the plate surface on which the grooves are formed facing inward.
The welded pipe manufacturing apparatus according to claim 11.
a second vacuum chamber adjacent to the first vacuum chamber on the side where the first inlet of the first vacuum chamber is located and having a lower degree of vacuum than the first vacuum chamber;
a third vacuum chamber adjacent to the first vacuum chamber on the side where the first outlet of the first vacuum chamber is located and having a lower degree of vacuum than the first vacuum chamber;
Furthermore,
The second vacuum chamber includes a second inlet into which the band-shaped metal plate is fed from the one end side by the feeding mechanism, and a second inlet into which the band-shaped metal plate is fed from the one end side by the feeding mechanism. a second outlet through which the band-shaped metal plate is sent out from the one end side, and the second outlet is connected to the first inlet, thereby communicating with the first vacuum chamber;
The third vacuum chamber includes a third inlet into which the welded pipe produced in the first portion of the band-shaped metal plate is sent out from the first outlet by the feeding mechanism, and a third inlet into which the welded pipe produced in the first portion of the band-shaped metal plate is fed by the feeding mechanism, and a third outlet through which the welded pipe made on the first portion of the metal plate is fed into the third inlet, and the third inlet is connected to the third inlet. communicating with the first vacuum chamber by connecting with one outlet;
The welded pipe manufacturing apparatus according to claim 11 or 12.
The first inlet, the second inlet, and the second outlet are a first gap in which the band-shaped metal plate can slide between the flat metal plate and the band-shaped metal plate with the band-shaped metal plate inserted therethrough. has
The first outlet, the third inlet, and the third outlet are arranged so that the welded pipe is inserted between the welded pipe and the first portion of the band-shaped metal plate. having a movable second gap;
The welded pipe manufacturing apparatus according to claim 13.
one end of the welded tube outside the first vacuum chamber is sealed, and the internal space of the welded tube is at the same vacuum as the inside of the first vacuum chamber;
The welded pipe manufacturing apparatus according to any one of claims 10 to 14.
a vacuum gauge that measures the degree of vacuum in the internal space of the first vacuum chamber;
a control device that determines the presence or absence of a welding defect in the welded pipe produced by the electron beam welding machine based on the measured value of the vacuum gauge;
further comprising,
The welded pipe manufacturing apparatus according to any one of claims 10 to 15.
Optics for determining the degree of vacuum in the internal space of the first vacuum chamber by measuring the spectrum of light emitted when electrons collide with the gas in the space communicating with the first vacuum chamber to determine the pressure of the gas. formula leak detector,
a control device that determines whether there is a welding defect in the welded pipe produced by the electron beam welding machine based on the degree of vacuum in the internal space determined by the optical leak detector;
further comprising,
The welded pipe manufacturing apparatus according to any one of claims 10 to 15.