JP2022147925A - Manufacturing method of press bending tube and press bending tube - Google Patents

Abstract

To provide a manufacturing method of press bending tube and a press bending tube that do not require weld, and a manufacturing method of press bending tube and a press bending tube that do not require weld and in which bulging can be suppressed.SOLUTION: By a reverse bending process (seventh process P7) of bending a plate 20 so as to be concave along a reverse bending band 30-8, the reverse bending band 30-8 is arranged adjacent to a part between two regions having an angle larger than 90 degrees when viewed from a first surface 23. In the last process in processes for processing a corner part, one of a lower die 16 and an upper die 15 is inserted from between a folding part 41 and a projection part 42. The manufacturing method of press bending tube includes a closure process of elastically deforming the plate 20, inserting the projection part 42 to the folding part 41, making a second connection part processing band 30-6 and a third connection part processing band 30-7 approach each other, and thereby, closing the plate 20 in a cylindrical shape.SELECTED DRAWING: Figure 8

Description

TECHNICAL FIELD The present invention relates to a press-bent tube manufacturing method and a press-bent tube.

Commercially available metal pipes represented by round pipes and square pipes are widely used for building materials, structural frames, and the like. Metal pipes that are assembled on-site for use are often pre-processed in a factory prior to on-site assembly in order to form bolt holes and the like for assembly in the pipe length direction at an appropriate pitch. However, drilling such bolt holes and the like in off-the-shelf, commercially available metal tubes is cumbersome and troublesome. Therefore, it is conceivable to prepare a flat plate instead of a commercially available metal pipe, perform required perforation processing, etc., and then perform bending forming such as roll forming or press forming to finish it as a square pipe.

Japanese Patent Application Laid-Open No. 5-92212

Conventionally, when a flat plate is bent into a pipe, it is necessary to weld the end surfaces of long joints extending in the pipe length direction to join them in a seamless pipe shape (see, for example, Patent Document 1). However, when the flat plate used is a color steel plate, the color surface is scorched by heat when the seam is welded, and the appearance and quality of the plate are greatly impaired. Repairing the burnt portion by painting or correcting the deformation requires much labor and time, which is inconveniently reflected in the pipe product cost.

Compared to using commercially available metal pipes with stipulated specifications such as size, the method of forming a square pipe after performing the required pre-processing on a flat plate, if the above-mentioned problems in joining the mating surfaces can be resolved, It has the advantage of significantly increasing usability and flexibility.

The inventors of the present invention focused on the above advantages and studied a method of manufacturing a press-bent pipe from a plate material by press working in which the plate material is sandwiched from above and below by an upper die and a lower die and bent. However, if the four corners of the press-bent tube viewed in cross section are only bent at 90 degrees in order, the upper die or the lower die inserted into the press-bent tube will not be bent when the final bending process is performed. The edges are tightly pinched. As a result, since the last bent portion has an obtuse angle, when the edges of the plate material are finally brought closer, one or more surfaces of the press-bent tube bulge outward, easily impairing the quality.

One of the objects of the present invention is to provide a press-bent tube manufacturing method and a press-bent tube that do not require welding. One of the objects of the present invention is to provide a press-bent pipe manufacturing method and a press-bend pipe that do not require welding and can suppress swelling.

A press-bent tube manufacturing method of a first aspect is a press-bent tube manufacturing method for manufacturing a press-bent tube from a metal sheet material, wherein the sheet material has a first edge and a second edge. The board has a first surface extending from the first edge to the second edge, and the board extends from the first edge to the second edge opposite the first surface. a second surface having a second surface, the method comprising: performing a bend in the sheet material along a plurality of parallel working zones located between the first edge and the second edge; , the bending is performed by a press work that bends the plate material with the plate material sandwiched by a combination of one or more lower dies and one of the one or more upper dies, and the bending is performed by the first a convex bend that bends convexly when viewed from a surface; and a concave bend that bends concavely when viewed from a first surface; one joint processing band, a second joint processing band positioned between the first joint processing band and the second edge, the second joint processing band and the second edge and three or more corner processing bands located between the second connection processing band and the third connection processing band, and press bending The pipe manufacturing method includes a first connection portion processing step of concavely bending the plate material along the first connection portion processing band, and a second connection step of convexly bending the plate material along the second connection portion processing band. a third connecting portion processing step of convexly bending the plate material along the third connecting portion processing band; and a corner processing band of convexly bending the plate material along each corner processing band. and a corner portion processing step several times, wherein the first connecting portion processing step and the second connecting portion processing step form a folded portion to be accommodated inside the press bent pipe at the first end. A protrusion that is included in the portion from the edge to the second connecting portion processing band and that is housed inside the press bent tube and connected to the folded portion by the third connecting portion processing step is formed at the second end. Included in the portion from the edge to the third connecting portion processing zone, one of the corner processing steps includes the first connecting portion processing step, the second connecting portion processing step, and the third connecting portion processing step. is executed after all of the corner processing step and the other corner processing steps are completed, and in the one step of the corner processing steps, one of the lower mold and the upper mold is used to form the folded portion and the projecting portion. The method for manufacturing a press-bent pipe further includes elastically deforming the plate material to insert the projecting portion into the folded portion after the one step of the corner portion processing steps, and inserting the second connecting portion. Work zone and third connecting part A method for manufacturing a press-bent pipe, including a closing step of closing the plate material into a tubular shape by bringing the work band close to the work zone.

According to the first aspect, since the plate material is closed into a tubular shape by inserting the protruding portion into the folded portion, the press-bent pipe can be manufactured without welding.

A method for manufacturing a press-bent pipe according to a second aspect, wherein the working zone includes a reverse bending zone positioned between a second connecting part working zone and a third connecting part working zone, and The method includes a reverse bending step of making a concave bend in the sheet material along the reverse bending band, the reverse bending step causing the reverse bending band to form an angle of greater than 90 degrees with respect to the first surface2. are arranged adjacently between the two regions, and the one step of the corner portion processing steps includes a first connecting portion processing step, a second connecting portion processing step, and a third connecting portion processing step. , another corner processing step, and the reverse bending step are all completed.

According to the second aspect, since the concave bending is performed on the reverse bending band, when compared to the case where the reverse bending band is not subjected to concave bending, the last step of the corner processing step of three or more times is performed. In one corner processing step, the inserted lower mold or upper mold can be prevented from coming into strong contact with the plate material, and as a result, unintended bulging of the plate material can be suppressed.

A third aspect of the method for manufacturing a press-bent pipe is a first corner processing zone in which three or more corner processing zones are positioned between a second connecting zone processing zone and a third connecting zone processing zone. A band, a second corner processing band located between the first corner processing band and the third connection processing band, and a second corner processing band and a third connection processing band. a third corner working zone located between and a fourth corner working zone located between the third corner working zone and the third connection working zone, the press bending tube comprising: The manufacturing method includes a first corner processing step of convexly bending the plate material along the first corner processing band, and a second corner processing step of convexly bending the plate along the second corner processing band. A processing step, a third corner processing step of convexly bending the plate along the third corner processing band, and a fourth corner of convexly bending the plate along the fourth corner processing band. a processing step, wherein the first corner processing step causes the first corner processing zone to be positioned adjacent between two regions that are 90 degrees to each other when viewed from the second surface; The second corner processing step places the second corner processing zone adjacently between two regions that are 90 degrees to each other when viewed from the second surface, and the third corner processing step provides: A third corner working zone is positioned adjacently between two regions that are 90 degrees to each other when viewed from the second surface, and a fourth corner working step creates a fourth corner working zone. , between two regions that are at 90 degrees to each other when viewed from the second surface, and the reverse bending process causes the reverse bending zone to subtend an angle greater than 90 degrees when viewed from the first surface. The second corner processing step is one of the second corner processing step and the third corner processing step. 2. A press-bent tube manufacturing method according to the second aspect.

According to the third aspect, since the concave bending is performed on the reverse bending band, compared to the case where the reverse bending band is not subjected to the concave bending, the second bending performed last in the corner processing step is reduced. In the corner processing step 1 or the corner processing step 3, the inserted lower mold or upper mold can be prevented from strongly contacting the plate material, and as a result, unintended bulging of the plate material can be suppressed.

In the method for manufacturing a press-bent pipe according to the fourth aspect, the distance between the first corner processing zone and the second connection processing zone is equal to the distance between the third connection processing zone and the fourth corner processing zone. longer than the distance between, the reverse bending band is located between the second corner processing band and the third corner processing band, and the distance between the second corner processing band and the reverse bending band is shorter than the distance between the reverse bending zone and the third corner processing zone, and the first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, the third In a third aspect, the second corner processing step is performed after all of the first corner processing step, the third corner processing step, the fourth corner processing step, and the reverse bending processing are completed. The method of manufacturing a press-bent tube described.

According to the fourth aspect, compared to the case where the distance between the second corner processing zone and the reverse bending zone is longer than the distance between the reverse bending zone and the third corner processing zone Even if the angle formed by the two regions adjacent to both sides of the reverse bending band is the same, the third connecting portion processing band can be moved away from the second connecting portion processing band, and as a result, the folded portion and the protrusion It is easy to prevent contact between the plate material and the upper mold or the lower mold due to strong force by opening a large space between the parts.

In the fifth aspect of the press-bent tube manufacturing method, the distance between the first corner processing zone and the second connection processing zone is equal to the distance between the third connection processing zone and the fourth corner processing zone. is shorter than the distance between, the reverse bending band is located between the second corner processing band and the third corner processing band, and the distance between the second corner processing band and the reverse bending band is longer than the distance between the reverse bending zone and the third corner processing zone, and the first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, the third In a third aspect, the third corner processing step is performed after all of the first corner processing step, the second corner processing step, the fourth corner processing step, and the reverse bending processing are completed. The method of manufacturing a press-bent tube described.

According to the fifth aspect, compared to the case where the distance between the second corner processing zone and the reverse bending zone is shorter than the distance between the reverse bending zone and the third corner processing zone Even if the angle formed by the two regions adjacent to both sides of the reverse bending band is the same, the third connecting portion processing band can be moved away from the second connecting portion processing band, and as a result, the folded portion and the protrusion It is easy to prevent contact between the plate material and the upper mold or the lower mold due to strong force by opening a large space between the parts.

The press-bent tube manufacturing method of the sixth aspect includes reverse bending such that the inserted lower die or upper die is separated from the plate material at the end of the one step of the corner portion forming steps. A method of manufacturing a press-bent tube according to any one of the second to fourth aspects, wherein the angle of the concave bend along the band is set.

According to the sixth aspect, since the inserted lower die or upper die is separated from the plate material at the end of the one step of the corner processing steps, the plate material and the upper die or lower die are separated from each other. It is easy to prevent contact with strong force.

In the method for manufacturing a press-bent tube according to the seventh aspect, in the second connection portion processing step, the third connection portion processing step, and each corner portion processing step, the lower die is a female die, and the upper die is a female die. The male punch is a male punch, and in the first connecting portion processing step and the reverse bending step, the lower die is a male punch and the upper die is a female die. A press-bent tube manufacturing method according to any one of the aspects.

According to the seventh aspect, throughout the first connection portion processing step, the second connection portion processing step, the third connection portion processing step, each corner portion processing step, and the reverse bending step, the first The work can be simplified by eliminating the replacement of the upper and lower sides of the surface and the second surface.

In the eighth aspect of the method for manufacturing a press-bent tube, in the second connection portion processing step, the third connection portion processing step, and each corner portion processing step, the lower die is a male punch and the upper die is a male punch. It is a female die, and in the first connecting portion processing step and the reverse bending step, the lower die is a female die and the upper die is a male punch. A press-bent tube manufacturing method according to any one of the aspects.

According to the eighth aspect, throughout the first connection portion processing step, the second connection portion processing step, the third connection portion processing step, each corner portion processing step, and the reverse bending step, the first The work can be simplified by eliminating the replacement of the upper and lower sides of the surface and the second surface.

A press-bent tube of a ninth aspect is a press-bent tube manufactured from a metal plate, the plate having a first edge and a second edge, and the plate having a first edge. The plate includes a folded portion located on the edge side and a protrusion portion located on the second edge side, wherein the plate is bent between the first edge and the second edge in a positional relationship along the plate. A plurality of machined parallel working zones, the working zones being a bent first connection working zone located inside the press bend tube and at least partially outside the press bending tube. a bent second connection zone and a third bent connection zone located at least partially external to the press bend tube, the second connection zone and the third 3 are adjacent to each other, the plate material is partially formed into a tubular shape, and the folded portion is formed inside the press-bent tube by the first end edge and the first connection portion processing. and a second region connecting the first connecting portion working band and the second connecting portion working band inside the press bending tube, wherein the first region and the second 2 region, the projection extends to connect the third connection processing band and the second edge, and the projection is within the clearance inside the press bending pipe By being partially located in the A portion of the plate material exposed to the outside of the press-bent pipe includes three or more corner-worked bands, and each corner-worked band has a convexly bent shape when viewed from the outside of the press-bent pipe. , is a press-bent tube.

According to the ninth aspect, since the press-bent pipe has a shape in which the plate member is cylindrically closed by inserting the projecting portion into the folded portion during processing, the press-bent pipe can be manufactured without welding.

The press-bent pipe of the tenth aspect includes a reverse-bending band in a portion of the plate material exposed to the outside of the press-bending pipe, and the reverse-bending band when viewed from the outside of the press-bending pipe. is a press-bent tube according to the ninth aspect, having a concavely bent shape.

According to the tenth aspect, since the press-bent tube includes a concavely bent reverse bending band, when compared to a case in which the reverse bending band is not included, during processing of the last corner bending band, the insertion It is possible to prevent the lower die or the upper die which has been formed from coming into strong contact with the plate material, and as a result, it is possible to suppress unintended bulging of the press-bent tube.

According to the present invention, it is possible to provide a press-bent pipe manufacturing method and a press-bend pipe that do not require welding. Furthermore, according to the present invention, it is possible to provide a press-bent pipe manufacturing method and a press-bend pipe that do not require welding and can suppress swelling.

1 is a schematic front view of an exemplary press machine used in the press-bent tube manufacturing method according to the first embodiment; FIG. FIG. 10 is a side view of a plate material in a 0th state S0 to a 2nd state S2 during execution of the press-bent pipe manufacturing method according to the first embodiment; FIG. 8A is a side view of a plate material in a third state S3 to a fourth state S4 during execution of the press-bent tube manufacturing method according to the first embodiment; FIG. 10 is a side view of the plate material in fifth state S5 to seventh state S7 during execution of the press-bent pipe manufacturing method according to the first embodiment. FIG. 10 is a side view of the plate material in eighth state S8 to ninth state S9 during the execution of the press-bent tube manufacturing method according to the first embodiment; 1 shows a first step P1 to a third step P3 of the press-bent tube manufacturing method according to the first embodiment. 4 shows a fourth step P4 to a sixth step P6 of the press-bent tube manufacturing method according to the first embodiment. 7 shows a seventh process P7 to a ninth process P9 of the press-bent tube manufacturing method according to the first embodiment. A tenth step P10 of the press-bent tube manufacturing method according to the first embodiment is shown. It is a side view which shows the shape in the middle of processing of the board|plate material in 2nd Embodiment. It is a side view which shows the shape in the middle of processing of the board|plate material in 3rd Embodiment. It is a side view which shows the shape in the middle of processing of the board|plate material in 4th Embodiment.

<First embodiment>
(press machine)
FIG. 1 is a schematic front view of an exemplary press machine 10 used in the press-bent tube manufacturing method of the present embodiment. The press machine 10 includes two frames 11 extending in the Z direction (vertical direction) fixed to an installation site 17 at the left and right ends. The press machine 10 further includes a lower table 12 mounted below the frames 11 and extending in the X direction (horizontal direction) between the frames 11 . The press machine 10 further includes a driving source 13 such as a servomotor mounted on the frame 11 and an upper table 14 that is vertically movable with respect to the frame 11 by the power of the driving source 13 .

The press machine 10 further includes one or more upper dies 15 extending continuously or intermittently in the X direction at the lower end of the upper table 14 and continuously or intermittently in the X direction at the upper end of the lower table 12 . , and one or more lower dies 16 extending intermittently. One upper mold 15 may be composed of a combination of a plurality of molds. One lower mold 16 may be composed of a combination of a plurality of molds. A space is provided in the Z direction between the upper mold 15 and the lower mold 16 . When the workpiece is placed between the upper die 15 and the lower die 16 and the upper table 14 is lowered toward the lower table 12, the workpiece is bent, for example, bent according to the configuration of the upper die 15 and the lower die 16. Processing such as pressing or molding is applied.

The press machine 10 is equipped with an automatic changer called an ATC device (auto tool changer) (not shown), and the combination of the upper die 15 and the lower die 16 used for processing is changed by a program according to the process or by an external command. can be changed automatically. The combination of the upper mold 15 and the lower mold 16 used for processing may be manually changeable. Also, in another example, the lower table 12 may be relatively movable with respect to the fixed upper table 14 . Also, in another example, both the lower table 12 and the upper table 14 may be made movable relative to each other.

(plate material)
A press-bent pipe manufacturing method for manufacturing a press-bent pipe 50 (FIG. 5) from a flat metal plate 20 (FIG. 2) will be described below. Expressions such as "first" and "second" are merely expressions for identifying steps or members, and do not limit any order, such as the order of steps, unless otherwise specified.

The plate material 20 is color-coated. Since the colored plate material 20 loses the color coating when welded, it is preferable to make the press-bent pipe 50 (FIG. 5) by the press-bent pipe manufacturing method of the present embodiment that does not involve welding. In the following description, the plate material 20 before processing is a flat plate having a rectangular surface. The plate member 20 may have a hole formed therein, a notch may be provided at an end portion, or a part thereof may be processed in some way. In another example, the plate material 20 may not be painted.

2 to 4 are side views of the plate material 20 viewed from the same side along the X direction during the press-bent tube manufacturing method. FIG. 2 is a side view of the plate member 20 in the 0th state S0 to the second state S2. 3A and 3B are side views of the plate member 20 in the third state S3 to the fourth state S4. 4A and 4B are side views of the plate member 20 in the fifth state S5 to the seventh state S7. FIG. 5 is a side view of the plate member 20 in the eighth state S8 to the ninth state S9. Hereinafter, unless otherwise specified, the angle and length of the plate member 20 represent the angle and length when considered in a cross section perpendicular to the X direction.

The 0th state S0 in FIG. 2 shows the plate material 20 before processing. The plate 20 has a first edge 21 and a second edge 22 parallel to each other. A portion of the first edge 21 or the second edge 22 may include a non-parallel portion. The first edge 21 and the second edge 22 extend in a direction perpendicular to the drawing. Plate 20 further has a first surface 23 extending from first edge 21 to second edge 22 . The first surface 23 forms part of the outer surface of the press bent tube 50 (FIG. 5) after machining. Plate 20 also has a second surface 24 extending from first edge 21 to second edge 22 opposite first surface 23 . The second surface 24 forms part of the inner surface of the press bent tube 50 (FIG. 5) after machining.

In the method of manufacturing a press-bent tube, a plurality of mutually parallel working zones 30 (labeled 30-1 to 30-8 to be described later) positioned between a first end edge 21 and a second end edge 22 are formed. and the parts labeled 30-1 to 30-8 may be simply referred to as the processing zone 30 without distinction)). include. Bending is performed by press working in which the plate material 20 is sandwiched by a combination of one of the one or more lower dies 16 and one of the one or more upper dies 15 to bend the plate material 20 . Bending includes convex bending, which is convex when viewed from the first surface 23 , and concave bending, which is concave when viewed from the first surface 23 .

As shown in the 0th state S0 of FIG. 2, eight working zones 30 separated by dashed lines are defined on the plate material 20. As shown in FIG. Each working band 30 extends in a direction orthogonal to the drawing with a constant width. For convenience of explanation, the working zone 30 may be divided and shown, but the boundary of the working zone 30 does not need to be actually visible. For example, the expression “between A and B” with respect to the position of the working zone 30 may indicate the positional relationship along the plate material 20 or the positional relationship before working, unless there is a particular contradiction.

The first corner processing band 30-1 is located between the first edge 21 and the second edge 22. As shown in FIG. A second corner processing band 30-2 is located between the first corner processing band 30-1 and the second edge 22. As shown in FIG. A third corner processing band 30-3 is located between the second corner processing band 30-2 and the second edge 22. As shown in FIG. A fourth corner processing band 30-4 is located between the third corner processing band 30-3 and the second edge 22. As shown in FIG. The first corner processing band 30-1 to the fourth corner processing band 30-1 may be simply referred to as corner processing bands without distinction.

The first joint processing band 30-5 is positioned between the first edge 21 and the first corner processing band 30-1. The second joint processing band 30-6 is located between the first joint processing band 30-5 and the first corner processing band 30-1. A third joint processing band 30-7 is located between the fourth corner processing band 30-4 and the second edge 22. As shown in FIG. The reverse bending band 30-8 is located between the second joint processing band 30-6 and the third joint processing band 30-7.

In other examples, the reverse bend zone 30-8 may be at other locations between the second joint zone 30-6 and the third joint zone 30-7.

As shown in the 0th state S0 of FIG. 2, the plate member 20 includes first region 31-1 to ninth region 31-9 (hereinafter sometimes referred to as region 31 without distinction). For convenience of explanation, the regions 31 may be separated by dashed lines, but the boundaries of the regions 31 do not need to be actually visible.

The first region 31-1 spreads in a form connecting between the first edge 21 and the first connecting portion processing band 30-5. The second region 31-2 spreads in a form connecting between the first connecting portion processing band 30-5 and the second connecting portion processing band 30-6. The third region 31-3 extends in a form connecting between the second connecting portion processing band 30-6 and the first corner processing band 30-1. The fourth region 31-4 extends in a form connecting between the first corner processing zone 30-1 and the second corner processing zone 30-2.

A fifth region 31-5 extends in a form connecting between the second corner processing band 30-2 and the reverse bending processing band 30-8. A sixth region 31-6 extends in a form connecting between the reverse bending zone 30-8 and the third corner processing zone 30-3. The seventh region 31-7 extends in a form connecting between the third corner processing zone 30-3 and the fourth corner processing zone 30-4. The eighth region 31-8 extends in a form connecting between the fourth corner processing band 30-4 and the third connection processing band 30-7. The ninth region 31-9 spreads in a form connecting between the third connecting portion processing band 30-7 and the second edge 22. As shown in FIG.

(Manufacturing method for press-bent pipe)
6 to 9 are diagrams for explaining the steps of the press-bent tube manufacturing method. 6-9, the press machine 10 (FIG. 1) is viewed from the same side in the X direction. FIG. 6 shows a first process P1 to a third process P3. FIG. 7 shows a fourth step P4 to a sixth step P6. FIG. 8 shows the seventh step P7 to the ninth step P9. FIG. 9 shows a tenth step P10. The left side of FIGS. 6 to 9 corresponds to the front side of FIG. 1, that is, the outside of the press machine 10 and the side where the operator is present. 6 to 9 correspond to the inner side of FIG. 1, that is, the inside of the press machine 10. FIG. The bending angle of the plate material 20 represents the angle obtained by virtually extending the two regions 31 on both sides of the working band 30 .

First, the plate material 20 in the 0th state S0 of FIG. 2 is prepared. In this specification, the first upper mold 15-1 to the tenth upper mold 15-10 may be collectively referred to as the upper mold 15. As shown in FIG. The first lower mold 16-1 to the tenth lower mold 16-10 are collectively called the lower mold 16 in some cases. One or more upper dies 15 may be the same as other upper dies 15 or lower dies 16 unless contradictory, and one or more lower dies 16 may be the same as other upper dies 15 or lower dies 16. may be the same.

Next, in the first step P1 in FIG. 6, first, the first surface 23 of the first connecting portion processing band 30-5 is directed toward the male first upper mold 15-1, and The first edge 21 is arranged inside the press machine 10 compared to the second edge 22, with the surface 24 of the mold 2 facing the second lower mold 16-1, which is a female mold. Next, the plate member 20 is concave-bent along the first connecting portion processing band 30-5 by the first upper mold 15-1 and the second lower mold 16-1. The plate material 20 is put into the first state S1 of FIG. 2 by the first step P1 of FIG. In the first state S1, the angle between the first region 31-1 and the second region 31-2 is greater than 0 degrees and less than 90 degrees.

In the second step P2 following the first step P1 in FIG. 6, first, the second surface 24 of the second connecting portion processing band 30-6 is directed toward the male second upper mold 15-2. And, with the first surface 23 facing the second lower mold 16-2 which is a female mold, the first edge 21 is arranged inside the press machine 10 compared to the second edge 22. do. Next, the plate material 20 is convexly bent along the second connecting portion processing band 30-6 by the second upper mold 15-2 and the second lower mold 16-2. By the first step P1 in FIG. 6, the plate material 20 is brought into the second state S2 in FIG. In the second state S2, the angle between the second region 31-2 and the third region 31-3 is approximately 90 degrees.

By the first step P1 and the second step P2, the folded portion 41 to be accommodated inside the press bending tube 50 (FIG. 5) is formed between the first edge 21 and the second connecting portion processing zone. 30-6. The folded portion 41 is formed in a V shape by the first region 31-1, the second region 31-2, and the second connecting portion processing band 30-6.

In the third step P3 following the second step P2 in FIG. 6, first, the second surface 24 of the third connecting portion processing band 30-7 is directed toward the male third upper mold 15-3. And, with the first surface 23 facing the third lower mold 16-3 which is a female mold, the second edge 22 is arranged inside the press machine 10 compared to the first edge 21. do. Next, the plate material 20 is convexly bent along the third joint processing band 30-7 by the third upper mold 15-3 and the third lower mold 16-3. By the third step P3 in FIG. 6, the plate material 20 is brought into the third state S3 in FIG. In the third state S3, the angle between the eighth region 31-8 and the ninth region 31-9 is approximately 90 degrees.

In the third step P3, the protruding portion 42 that is housed inside the press bending tube 50 (FIG. 5) and is connected to the folded portion 41 is formed between the second edge 22 and the third connecting portion processing band 30. -7.

In the fourth step P4 in FIG. 7 following the third step P3 in FIG. 6, first, the second surface 24 of the first corner processing band 30-1 is formed by the fourth upper die 15-, which is a male type. 4 and with the first surface 23 facing the female fourth lower die 16-4, the first edge 21 of the press machine 10 is positioned lower than the second edge 22. Place inside. Next, the plate material 20 is convexly bent along the first corner processing band 30-1 by the fourth upper die 15-4 and the fourth lower die 16-4. By the fourth step P4 in FIG. 7, the plate material 20 is brought to the fourth state S4 in FIG. As a result of the fourth step P4, as shown in the fourth state S4, the first corner processing zones 30-1 are formed into the third regions 31-3 that form an angle of 90 degrees with each other when viewed from the second surface 24. and the fourth region 31-4.

In a fifth step P5 subsequent to the fourth step P4 in FIG. 7, first, the second surface 24 of the fourth corner processing zone 30-4 is directed toward the male fifth upper die 15-5. And, with the first surface 23 facing the female fifth lower mold 16-5, the second edge 22 is arranged inside the press machine 10 compared to the first edge 21. do. Next, the plate member 20 is convexly bent along the fourth corner processing band 30-4 by the fifth upper die 15-5 and the fifth lower die 16-5. By the fifth step P5 in FIG. 7, the plate material 20 is brought to the fifth state S5 in FIG. As a result of the fifth step P5, as shown in the fifth state S5, the fourth corner processing zone 30-4 is formed into the seventh region 31-7 which is 90 degrees to each other when viewed from the second surface 24. and the eighth region 31-8.

In a sixth step P6 following the fifth step P5 in FIG. 7, first, the second surface 24 of the third corner processing band 30-3 is directed toward the sixth upper die 15-6 which is a male type. And, with the first surface 23 facing the female sixth lower mold 16-6, the second edge 22 is arranged inside the press machine 10 compared to the first edge 21. do. Next, the plate material 20 is convexly bent along the third corner processing zone 30-3 by the sixth upper die 15-6 and the sixth lower die 16-6. By the sixth step P6 in FIG. 7, the plate member 20 is brought to the sixth state S6 in FIG. As a result of the sixth step P6, as shown in a sixth state S6, the third corner processing zone 30-3 is formed into a sixth region 31-6 that forms an angle of 90 degrees with respect to the second surface 24. and the seventh region 31-7.

In the seventh step P7 in FIG. 8 following the sixth step P6 in FIG. 7, first, the first surface 23 of the reverse bending band 30-8 is directed toward the male seventh upper die 15-7. And, with the second surface 24 facing the seventh lower mold 16-7 which is a female mold, the second edge 22 is arranged inside the press machine 10 compared to the first edge 21. do. Next, the sheet material 20 is concavely bent along the reverse bending band 30-8 by the seventh upper die 15-7 and the seventh lower die 16-7. By the seventh step P7 in FIG. 8, the plate material 20 is brought to the seventh state S7 in FIG.

As a result of the seventh step P7, as shown in a seventh state S7, the reverse bending zone 30-8 forms an angle greater than 90 degrees with respect to the first surface 23 with the fifth region 31-5. It is arranged adjacent to and between the sixth region 31-6. The angle between the fifth region 31-5 and the sixth region 31-6, viewed from the first surface 23, is greater than 90 degrees, eg approximately 173 degrees. The angle between the fifth region 31-5 and the sixth region 31-6 is greater than 90 degrees from the viewpoint of preventing excessive denting of the surface of the finished product and omitting correction of the excessive denting. It is preferably within a range of less than 180 degrees, for example, within a range of greater than 170 degrees and less than 180 degrees.

In the eighth step P8 following the seventh step P7 in FIG. 8, first, the second surface 24 of the second corner processing band 30-2 is directed toward the eighth upper die 15-8 of the male type. And, with the first surface 23 facing the eighth lower mold 16-8 which is a female mold, the second edge 22 is arranged inside the press machine 10 compared to the first edge 21. do. Next, the plate material 20 is convexly bent along the second corner processing band 30-2 by the eighth upper die 15-8 and the eighth lower die 16-8.

Before the eighth step P8 is performed, the fourth region 31-4 and the fifth region 31-5 are horizontal, as shown in the seventh state S7 of FIG. The projecting portion 42 is relatively separated. During the eighth step P8, the eighth upper die 15-8 in FIG. inserted below. By the eighth process P8 in FIG. 8, the plate member 20 is brought into the eighth state S8 in FIG. As a result of the eighth step P8, as shown in an eighth state S8, the second corner processing zone 30-2 is formed into a fourth region 31-4 that forms an angle of 90 degrees with respect to the second surface 24. and the fifth region 31-5. As shown in FIG. 8, the fourth region 31-4 and the fifth region 31-5 are tilted about 45 degrees from the horizontal at the end of the eighth step P8.

along the reverse bending band 30-8 so that the inserted eighth upper mold 15-8 is separated from both the folded portion 41 and the projecting portion 42 at the end of the eighth step P8. The concave bend angle is set. In the eighth step P8, the folded portion 41 and the projecting portion 42 are relatively close to each other. The working zone 30-7 is completely separated from the eighth upper die 15-8.

In the absence of the reverse bending band 30-8, the folded portion 41, the projecting portion 42, or the third connecting portion processing band 30-7 strongly contacts the eighth upper die 15-8. However, in this embodiment, unintended bending does not occur. In another example, the folded portion 41, the projecting portion 42, or the third connecting portion processing band 30-7 may be in light contact with the eighth upper mold 15-8.

In the eighth state S8 of FIG. 5, the second connection portion processing band 30-6 and the third connection portion processing band 30-7 are arcuate with approximately the same curvature and approximately the same size. The first corner processing band 30-1, the second corner processing band 30-2, the third corner processing band 30-3, and the fourth corner processing band 30-4 have substantially the same curvature. are arc-shaped and have roughly the same size.

The length of the fifth area 31-5 and the length of the sixth area 31-6 are the same. In other examples, the length of the fifth region 31-5 may be shorter than the length of the sixth region 31-6. In other examples, the length of the fifth region 31-5 may be longer than the length of the sixth region 31-6. The length of the eighth region 31-8 is shorter than the length of the third region 31-3.

In a ninth step P9 following the eighth step P8 in FIG. 8, first, the first surface 23 of the third region 31-3 is directed toward the male ninth upper mold 15-9 (upward). . Furthermore, the first surfaces 23 of the fifth region 31-5 and the sixth region 31-6 are placed downward on a ninth lower mold 16-9 having a horizontal upper surface. Additionally, the second edge 22 is located inside the press 10 relative to the first edge 21 . Next, the third region 31-3 is pushed downward by the ninth upper mold 15-9 to elastically deform the plate member 20, thereby inserting the projecting portion 42 into the gap of the folded portion 41. As shown in FIG. The gap of the folded portion 41 is the space between the first region 31-1 and the second region 31-2 as shown in the eighth state S8 of FIG.

In the third region 31-3, closer to the second connecting portion processing band 30-6 than the center between the first corner processing band 30-1 and the second connecting portion processing band 30-6 It is preferable to press the part. This is because elastic deformation of the plate member 20 is likely to occur with a small force, and unintended deformation of the plate member 20 is easily prevented.

In a tenth step P10 in FIG. 9 following the ninth step P9 in FIG. 8, first, the second corner processing band 30-2 is arranged upward, and the fourth corner processing band 30-4 is arranged downward. , and the third corner processing zone 30-3 is arranged inside the press machine 10 compared to the first corner processing zone 30-1. Furthermore, the plate material 20 is formed by a tenth upper die 15-10 having an L-shaped recessed surface of approximately 90 degrees and a tenth lower die 16-10 having an L-shaped recessed surface of approximately 90 degrees. from above and below. As a result, the projecting portion 42 is completely inserted into the gap of the folded portion 41 . Further, the fifth region 31-5 and the sixth region 31-6 are formed at an angle of approximately 90 degrees or slightly less than 90 degrees with respect to the fourth region 31-4. Further, the eighth region 31-8 and the third region 31-3 are formed at approximately 90 degrees with respect to the seventh region 31-7.

A ninth process P9 in FIG. 8 and a tenth process P10 in FIG. are approached to close the plate material 20 in a cylindrical shape.

As a result of the tenth step P10 in FIG. 8, the press-bent tube 50 (which may be generally rectangular in other examples) having a cross section with rounded corners as in the ninth state S9 in FIG. Figure 5) is completed. A portion of the first surface 23 between the first corner processing band 30-1 and the second connecting portion processing band 30-6, and a fourth corner processing band 30 of the first surface 23 -4 and the portion between the third joint processing zone 30-7 are arranged so as to constitute one planar outer surface of the press bending processing tube 50 (FIG. 5). That is, the outer surface of the third region 31-3 and the outer surface of the eighth region 31-8 are generally arranged along one plane.

The outer surface of the fifth region 31-5 and the outer surface of the sixth region 31-6 form one generally planar outer surface of the press bent tube 50 (FIG. 5). In the ninth state S9 of FIG. 5, for simplification of the drawing, the outer surface of the fifth region 31-5 and the outer surface of the sixth region 31-6 are drawn so as to extend generally along one plane. However, in reality, it is slightly recessed inward around the reverse bending zone 30-8. The outer surface of the fourth region 31-4 and the outer surface of the seventh region 31-7 are generally parallel to each other and each constitute one planar outer surface of the press bent tube 50 (FIG. 5).

In the ninth state S9 of FIG. 5, the second region 31-2 and the ninth region 31-9 are generally parallel and in contact with each other on the first surface 23 side. The length of the second region 31-2 is shorter than the length of the ninth region 31-9. The length of the first region 31-1 is shorter than the length of the second region 31-2. The ninth region 31-9 has a length that fits in the gap between the first region 31-1 and the second region 31-2.

The step of bending the first connecting portion processing band 30-5 is called a first connecting portion processing step (first step P1 in FIG. 6). The step of bending the second connecting portion processing band 30-6 is called a second connecting portion processing step (second step P2 in FIG. 6). The step of bending the third connecting portion processing band 30-7 is called a third connecting portion processing step (third step P3 in FIG. 6). A step of bending the first corner processing band 30-1 is called a first corner processing step (fourth step P4 in FIG. 7). A step of bending the fourth corner processing band 30-4 is called a fourth corner processing step (fifth step P5 in FIG. 7). The step of bending the third corner processing band 30-3 is called a third corner processing step (sixth step P6 in FIG. 7). The step of bending the reverse bending band 30-8 is called a reverse bending step (seventh step P7 in FIG. 8). The step of bending the second corner processing band 30-2 is called a second corner processing step (eighth step P8 in FIG. 8).

In this embodiment, the first connecting portion processing step (first step P1 in FIG. 6), the second connecting portion processing step (second step P2 in FIG. 6), and the third connecting portion processing step ( 6 third step P3), first corner processing step (fourth step P4 in FIG. 7), fourth corner processing step (fifth step P5 in FIG. 7), third corner After the processing step (sixth step P6 in FIG. 7) and the reverse bending step (seventh step P7 in FIG. 8) are completed in this order, the second corner processing step (eighth step in FIG. 8) is performed. Step P8) is performed. In another example, the steps prior to the second corner processing step (eighth step P8 in FIG. 8) may be performed in another order.

(Description of shape)
By the press-bent tube manufacturing method of the present embodiment, the press-bent tube 50 as shown in the ninth state S9 of FIG. 5 is manufactured from the metal plate material 20 shown in the state S0 of FIG. The plate member 20 has a first edge 21 and a second edge 22 . The plate member 20 includes a folded portion 41 located on the first edge 21 side and a projecting portion 42 located on the second edge 22 side. The plate material 20 includes a plurality of bent processing bands 30 parallel to each other between the first edge 21 and the second edge 22 in the positional relationship along the plate material 20 .

The working zones 30 consist of a first bent joint working zone 30-5 located inside the press bending tube 50 and a second bent connecting zone 30-5 located at least partially outside the press bending tube 50. It includes a joint working zone 30-6 and a bent third joint working zone 30-7 located at least partially outside the press bend tube 50. As shown in FIG. The plate member 20 is partially formed into a tubular shape by the second connecting portion processing band 30-6 and the third connecting portion processing band 30-7 being adjacent to each other. From the viewpoint of maintaining the shape, it is preferable that the second connecting portion processing band 30-6 and the third connecting portion processing band 30-7 are in contact with each other, but they may be slightly separated from each other.

The folded portion 41 has a first region 31-1 connecting the first end edge 21 and the first connection band 30-5 inside the press bending tube 50, and a first region 31-1 inside the press bending tube 50. It includes a second region 31-2 connecting the first joint processing band 30-5 and the second joint processing band 30-6. A gap exists between the first region 31-1 and the second region 31-2. The projecting portion 42 extends so as to connect the third connecting portion processing band 30-7 and the second edge 22. As shown in FIG. Since the projecting portion 42 is partially positioned in the gap inside the press bending tube 50, the gap between the second connection portion processing band 30-6 and the third connection portion processing band 30-7 is reduced. It is configured such that the movement in the spreading direction (movement to open and close in the vertical direction in FIG. 5) is suppressed. From the viewpoint of shape maintenance, the projecting portion 42 is preferably sandwiched and fixed while being in contact with both the first region 31-1 and the second region 31-2, but may be slightly separated. .

Four corner processing zones (first corner processing zone 30-1 to fourth corner processing zone 30-4 ) and a reverse bending zone 30-8. When viewed from the outside of the press bending tube 50, each corner processing band 30-1 has a convex shape (that is, it has a convex shape toward the outside). When viewed from the outside of the press bending tube 50, the reverse bending band 30-8 has a slightly concave shape (that is, convex toward the inside).

(summary)
According to this embodiment, the plate member 20 is closed into a tubular shape by inserting the protruding portion 42 into the folded portion 41, so that the press-bent pipe 50 (FIG. 5) can be manufactured without welding.

According to the present embodiment, since the concave bending is performed on the reverse bending band 30-8, compared to the case where the reverse bending band 30-8 is not subjected to concave bending, four corner processing steps are required. In the final second corner processing step (the eighth step P8 in FIG. 8), the inserted upper mold 15 can be prevented from strongly contacting the plate material 20, and as a result, the plate material 20 is unintentionally cut. Swelling can be suppressed.

According to the present embodiment, at the end of the last second corner processing step (eighth step P8 in FIG. 8) of the four corner processing steps, the inserted upper die 15 is removed from the plate material 20 . , it is easy to prevent contact between the plate member 20 and the upper die 15 due to a strong force.

In another example, in one or more of the first process P1 to the eighth process P8 of FIGS. good too. In the step performed after the second corner processing step (sixth step P6 in FIG. 7) or the third corner processing step (eighth step P8 in FIG. 8), the lower mold and the upper mold One of the male punches is inserted from between the folded portion 41 and the projecting portion 42 . After such a subsequent step, the plate member 20 is elastically deformed to insert the projecting portion 42 into the folded portion 41 . A recess along reverse bending band 30-8 is provided so that, at the end of such subsequent steps, the inserted lower or upper tool is spaced from (or in light contact with) sheet material 20. The bend angle is set. Even in such another example, the same effects as those of the first embodiment can be obtained.

In addition, the press-bent tube 50 (FIG. 5) manufactured in the first embodiment has four corner processing zones (30-1 to 30-4) and has a generally quadrangular cross-sectional shape perpendicular to the longitudinal direction. be. In other examples, the press bent tube may have a triangular cross-section with three corner bands, or may have five or more corner bands. The corner machining process is performed the number of times of the corner machining zones. A specific one of the corner processing steps includes a first connecting portion processing step, a second connecting portion processing step, a third connecting portion processing step, another corner processing step, and a reverse bending step. is executed after all In one of the corner processing steps, one of the lower die and the upper die is inserted from between the folded portion and the projecting portion. The same effect as in the first embodiment can be obtained even when the number of corner processing zones is other than four.

<Second embodiment>
FIG. 10 is a side view showing the shape of the plate material 120 during processing in the second embodiment. FIG. 10 shows the shape of the plate member 120 in a state corresponding to the eighth state S8 of the first embodiment of FIG. 5 and 10, except for the 100th digit, the constituent elements having the same numerical reference are locally processed into the same shape by the same process unless otherwise specified.

In this embodiment, unlike the first embodiment, the distance between the first corner processing band 130-1 and the second connection processing band 130-6 is the distance between the third connection processing band 130- 7 and the fourth corner processing zone 130-4. In other words, the length of the third region 131-3 is shorter than the length of the eighth region 131-8.

In the present embodiment, a first connecting portion processing step (similar to the first step P1 in FIG. 6), a second connecting portion processing step (similar to the second step P2 in FIG. 6), and a third connecting portion Processing step (similar to the third step P3 in FIG. 6), first corner processing step (similar to the fourth step P4 in FIG. 7), fourth corner processing step (fifth step in FIG. 7) P5), the second corner processing step (similar to the eighth step P8 in FIG. 8), and the reverse bending step (similar to the seventh step P7 in FIG. 8) are all completed, and then the third A corner processing step (similar to the sixth step P6 in FIG. 7) is performed. After the third corner processing step, steps similar to the ninth step P9 in FIG. 8 and the tenth step P10 in FIG. 9 of the first embodiment are performed.

Inserted upper mold (similar to the eighth upper mold 15-8 of the eighth step P8 of FIG. 8) at the end of the third corner processing step (similar to the sixth step P6 of FIG. 7) The angle of the concave bend along reverse bend band 130-8 is set such that the ridge is spaced from (or lightly touching) both folded portion 141 and protrusion 142. FIG.

(summary)
In this embodiment, in the step of elastically deforming the plate member 120 to insert the projecting portion 142 into the folded portion 141 (similar to the ninth step P9 in FIG. 8), a larger force is required than in the first embodiment. However, in other respects, the same effects as in the first embodiment can be obtained.

<Third Embodiment>
FIG. 11 is a side view showing the shape of the plate material 220 in the middle of processing according to the third embodiment. FIG. 11 shows the shape of the plate member 220 in a state corresponding to the eighth state S8 of the first embodiment of FIG. 5 and 11, except for the 100th digit, the constituent elements having the same numerical symbols are locally processed into the same shape by the same process unless otherwise specified. A description similar to that of the first embodiment is omitted.

In this embodiment, as in the first embodiment, the distance between the first corner processing band 230-1 and the second connecting portion processing band 230-6 is equal to that of the third connecting portion processing band 230. -7 and the fourth corner working zone 230-4. In other words, the length of the third region 231-3 is longer than the length of the eighth region 231-8.

Furthermore, in this embodiment, unlike the first embodiment, the length of the fifth region 231-5 is shorter than the length of the sixth region 231-6. In other words, the distance between second corner processing band 230-2 and reverse bending band 230-8 is equal to the distance between reverse bending band 230-8 and third corner processing band 230-3. shorter than distance.

First connecting portion processing step (similar to first step P1 in FIG. 6), second connecting portion processing step (similar to second step P2 in FIG. 6), third connecting portion processing step (FIG. 6 (similar to the third step P3 of FIG. 7), the first corner processing step (similar to the fourth step P4 in FIG. 7), the fourth corner processing step (similar to the fifth step P5 in FIG. 7), After the third corner processing step (similar to the sixth step P6 in FIG. 7) and the reverse bending processing step (similar to the seventh step P7 in FIG. 8) are all completed, the second corner processing step ( 8) is performed. After the second corner processing step, steps similar to the ninth step P9 in FIG. 8 and the tenth step P10 in FIG. 9 of the first embodiment are performed.

(summary)
According to this embodiment, the distance between the second corner processing band 230-2 and the reverse bending band 230-8 is the distance between the reverse bending band 230-8 and the third corner processing band 230-3. of the two regions 231 (i.e., the fifth region 231-5 and the sixth region 231-6) adjacent to each side of the reverse bending zone 230-8 when compared to the case of being longer than the distance between Even if the angles to be formed are the same, the third connecting portion processing band 230-7 can be kept away from the second connecting portion processing band 230-6, and as a result, the space between the folded portion 241 and the projecting portion 242 can be increased. can be opened wide.

In other words, two regions 231 (that is, a fifth region 231-5 and a sixth region 231-6) adjacent to both sides of the reverse bending zone 230-8 viewed from the first surface 223 side. Even if the angle is increased (that is, even if they are brought close to parallel), the space between the folded portion 241 and the projecting portion 242 is widened so that the plate material 220 and the upper mold (8th step of the eighth step P8 in FIG. 8) are separated. (similar to the upper mold 15-8 of )) can be easily prevented from contacting with a strong force.

<Fourth Embodiment>
FIG. 12 is a side view showing the shape of the plate material 320 in the middle of processing in the fourth embodiment. FIG. 12 shows the shape of the plate member 320 in a state corresponding to the eighth state S8 of the first embodiment of FIG. 5 and 12, except for the 100's place, the constituent elements having the same numerical symbols are locally processed into the same shape by the same process unless otherwise specified. A description similar to that of the first embodiment is omitted.

In this embodiment, unlike the first embodiment, the distance between the first corner processing band 330-1 and the second connection processing band 330-6 is the distance between the third connection processing band 330- 7 and the fourth corner processing zone 330-4. In other words, the length of the third region 331-3 is shorter than the length of the eighth region 331-8.

Furthermore, in this embodiment, unlike the first embodiment, the length of the fifth region 331-5 is longer than the length of the sixth region 331-6. In other words, the distance between second corner processing band 330-2 and reverse bending band 330-8 is equal to the distance between reverse bending band 330-8 and third corner processing band 330-3. longer than distance.

In the present embodiment, a first connecting portion processing step (similar to the first step P1 in FIG. 6), a second connecting portion processing step (similar to the second step P2 in FIG. 6), and a third connecting portion Processing step (similar to the third step P3 in FIG. 6), first corner processing step (similar to the fourth step P4 in FIG. 7), fourth corner processing step (fifth step in FIG. 7) P5), the second corner processing step (similar to the eighth step P8 in FIG. 8), and the reverse bending step (similar to the seventh step P7 in FIG. 8) are all completed, and then the third A corner processing step (similar to the sixth step P6 in FIG. 7) is performed. After the third corner processing step, steps similar to the ninth step P9 in FIG. 8 and the tenth step P10 in FIG. 9 of the first embodiment are performed.

(summary)
According to this embodiment, the distance between the second corner processing band 330-2 and the reverse bending band 330-8 is the distance between the reverse bending band 330-8 and the third corner processing band 330-3. of the two regions 331 (i.e., the fifth region 331-5 and the sixth region 331-6) adjacent to each side of the reverse bending zone 330-8 when compared to the case of being shorter than the distance between the Even if the angles to be formed are the same, the third connecting portion processing band 330-7 can be kept away from the second connecting portion processing band 330-6, and as a result, the space between the folded portion 341 and the projecting portion 342 can be increased. can be opened wide.

In other words, two regions 331 (that is, a fifth region 331-5 and a sixth region 331-6) adjacent to both sides of the reverse bending zone 330-8 viewed from the first surface 323 side. Even if the angle is increased (that is, even if they are brought close to parallel), the space between the folded portion 341 and the projecting portion 342 is widened so that the plate material 320 and the upper die (8th step of the eighth step P8 in FIG. 8) are separated. (similar to the upper mold 15-8 of )) can be easily prevented from contacting with a strong force.

<Fifth Embodiment>
From the first embodiment to the fourth embodiment, mainly the upper die (eg upper die 15 in FIGS. 6-8) is a male punch and the lower die (eg lower die 15 in FIGS. 6-8 16) is described as being a female die. In this embodiment, compared to the first to fourth embodiments, the first connecting portion processing step (eg, the first step P1 in FIG. 6) and the reverse bending step (eg, FIG. 8 In the seventh step P7) of , the upper mold and the lower mold are exchanged.

That is, in the present embodiment, in the first connecting portion processing step (for example, the first step P1 in FIG. 6) and the reverse bending step (for example, the seventh step P7 in FIG. 8), the lower mold is a male type. A punch is used, and the upper die is a female die. Furthermore, as in the first embodiment, a second connecting portion processing step (for example, the second step P2 in FIG. 6), a third connecting portion processing step (for example, the third step P3 in FIG. 6), a 1 corner processing step (for example, the fourth step P4 in FIG. 7), a fourth corner processing step (for example, the fifth step P5 in FIG. 7), and a third corner processing step (for example, the fourth step in FIG. 7). 6 process P6) and the second corner processing process (eighth process P8 in FIG. 8), the lower die is a female die and the upper die is a male punch.

(summary)
According to this embodiment, the first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, the first corner processing step, the second corner processing step, and the third Throughout the corner processing step, the fourth corner processing step, and the reverse bending step, the first surface (e.g., the first surface 23 shown in the 0th state S0 of FIG. 2) and the second surface ( For example, the work can be simplified by eliminating the need to replace the top and bottom of the second surface 24) shown in the 0th state S0 of FIG.

<Sixth Embodiment>
In this embodiment, compared to the first to fourth embodiments, the second connecting portion processing step (for example, the second step P2 in FIG. 6) and the third connecting portion processing step (for example, Third step P3 in FIG. 6), first corner processing step (for example, fourth step P4 in FIG. 7), fourth corner processing step (for example, fifth step P5 in FIG. 7), third The upper mold and the lower mold are exchanged in the corner processing step (for example, the sixth step P6 in FIG. 7) and the second corner processing step (eighth step P8 in FIG. 8).

That is, in the present embodiment, the second connecting portion processing step (for example, the second step P2 in FIG. 6), the third connecting portion processing step (for example, the third step P3 in FIG. 6), the first corner portion Processing step (for example, fourth step P4 in FIG. 7), fourth corner processing step (for example, fifth step P5 in FIG. 7), third corner processing step (for example, sixth step P6 in FIG. 7) ), and in the second corner processing step (eighth step P8 in FIG. 8), the lower die is a female die and the upper die is a male punch. Furthermore, as in the first embodiment, in the first connecting portion processing step (for example, the first step P1 in FIG. 6) and the reverse bending step (for example, the seventh step P7 in FIG. 8), the lower die is the male punch and the upper die is the female die.

(summary)
According to this embodiment, the first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, the first corner processing step, the second corner processing step, and the third Throughout the corner processing step, the fourth corner processing step, and the reverse bending step, the first surface (e.g., the first surface 23 shown in the 0th state S0 of FIG. 2) and the second surface ( For example, the work can be simplified by eliminating the need to replace the top and bottom of the second surface 24) shown in the 0th state S0 of FIG.

DESCRIPTION OF SYMBOLS 10... Press machine, 11... Frame, 12... Lower table, 13... Drive source,
14... upper table, 15... upper mold (15-1 to 15-10... first upper mold to tenth upper mold),
16 lower mold (16-1 to 16-10 second lower mold to tenth lower mold), 17 installation site,
20... plate material, 21... first edge, 22... second edge, 23... first surface,
24 ... second surface, 30 ... processing zone, 30-1 ... first corner processing zone,
30-2 ... second corner processing zone, 30-3 ... third corner processing zone,
30-4 ... fourth corner processing zone, 30-5 ... first connection processing zone,
30-6 ... second connecting portion processing band, 30-7 ... third connecting portion processing band,
30-8 ... reverse bending belt,
31... areas (31-1 to 31-9... first area to ninth area),
41... Folded part, 42... Protruding part, 50... Press bending tube,
S0 to S9: 0th state to 9th state, P1 to P10: 1st step to 10th step,
120... plate material, 130-1... first corner processing zone, 130-4... fourth corner processing zone,
130-6 ... second connecting portion processing band, 130-7 ... third connecting portion processing band,
130-8 ... reverse bending band, 131-3 ... third region, 131-8 ... eighth region,
141... Folded part, 142... Protruding part, 220... Plate material, 223... First surface,
230-1 ... first corner processing zone, 230-2 ... second corner processing zone,
230-3 ... third corner processing zone, 230-4 ... fourth corner processing zone,
230-6 ... second connecting portion processing band, 230-7 ... third connecting portion processing band,
230-8 ... reverse bending band, 231 ... region, 231-3 ... third region,
231-5... Fifth area, 231-6... Sixth area, 231-8... Eighth area,
241... Folded part, 242... Protruding part, 320... Plate material, 323... First surface,
330-1 ... first corner processing zone, 330-2 ... second corner processing zone,
330-3 ... third corner processing zone, 330-4 ... fourth corner processing zone,
330-6 ... second connecting portion processing band, 330-7 ... third connecting portion processing band,
330-8 ... reverse bending band, 331 ... region, 331-3 ... third region,
331-5... Fifth area, 331-6... Sixth area, 331-8... Eighth area,
341... Folding part, 342... Protruding part

Claims (10)

A press-bent tube manufacturing method for manufacturing a press-bent tube from a metal plate, comprising:
the plate has a first edge and a second edge,
said plate having a first surface extending from said first edge to said second edge;
said plate having a second surface opposite said first surface and extending from said first edge to said second edge;
The press-bent tube manufacturing method includes bending the sheet material along a plurality of mutually parallel working zones located between the first edge and the second edge,
The bending is performed by press working in which the plate material is sandwiched by a combination of one or more lower dies and one of one or more upper dies,
The bending includes convex bending that bends convexly when viewed from the first surface and concave bending that bends concavely when viewed from the first surface,
The working zone is
a first connection processing zone located between the first edge and the second edge;
a second connection processing band located between the first connection processing band and the second edge;
a third connection processing band located between the second connection processing band and the second edge;
Three or more corner processing zones located between the second connection processing zone and the third connection processing zone,
The press-bent tube manufacturing method comprises:
a first connecting portion processing step of concavely bending the plate material along the first connecting portion processing band;
a second connecting portion processing step of performing the convex bending on the plate material along the second connecting portion processing band;
a third connecting portion processing step of performing the convex bending on the plate material along the third connecting portion processing band;
a corner processing step of performing the convex bending on the plate material along each of the corner processing bands, the number of times of the corner processing bands;
including
By the first connecting portion processing step and the second connecting portion processing step, the folded portion to be accommodated inside the press-bent pipe extends from the first end edge to the second connecting portion. Included in the part up to the processing zone,
In the third connecting portion processing step, a projecting portion that is housed inside the press bending tube and connected to the folded portion extends from the second end edge to the third connecting portion processing zone. included in the part
One of the corner processing steps includes the first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, and the other corner processing step. is executed after all
In the one step of the corner processing steps, one of the lower mold and the upper mold is inserted from between the folded portion and the projecting portion,
The press-bent tube manufacturing method further comprises elastically deforming the plate material to insert the projecting portion into the folded portion after the one step of the corner processing steps, and forming the second connection. A closing step of closing the plate material into a tubular shape by bringing the part processing band and the third connecting portion processing band close to each other,
A press bending tube manufacturing method. The working zone includes a reverse bending working zone located between the second connecting part working zone and the third connecting part working zone,
The method for manufacturing a press-bent pipe includes a reverse bending step of concavely bending the plate material along the reverse bending band,
the reverse bending step causes the reverse bending band to be adjacently positioned between two regions that form an angle of greater than 90 degrees with respect to the first surface;
The one of the corner processing steps includes the first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, and the other corner processing step. Executed after all the steps and the reverse bending step are completed,
2. The method of manufacturing a press-bent pipe according to claim 1. The three or more corner processing zones are
a first corner processing band located between the second connection processing band and the third connection processing band;
a second corner processing zone positioned between the first corner processing zone and the third connection processing zone;
a third corner processing zone positioned between the second corner processing zone and the third connection processing zone;
a fourth corner processing zone positioned between the third corner processing zone and the third connection processing zone;
including
The press-bent tube manufacturing method comprises:
a first corner processing step of convexly bending the plate material along the first corner processing band;
a second corner processing step of convexly bending the plate material along the second corner processing band;
a third corner processing step of convexly bending the plate material along the third corner processing band;
a fourth corner processing step of convexly bending the plate material along the fourth corner processing band;
including
By the first corner processing step, the first corner processing zone is arranged adjacently between two regions that are 90 degrees to each other when viewed from the second surface;
By the second corner processing step, the second corner processing zone is arranged adjacently between two regions that are 90 degrees to each other when viewed from the second surface;
By the third corner processing step, the third corner processing zone is arranged adjacently between two regions that are 90 degrees to each other when viewed from the second surface;
By the fourth corner processing step, the fourth corner processing zone is arranged adjacently between two regions that are 90 degrees to each other when viewed from the second surface;
the reverse bending step causes the reverse bending band to be adjacently positioned between two regions that form an angle of greater than 90 degrees with respect to the first surface;
The one of the corner processing steps is one of the second corner processing step and the third corner processing step,
3. The method of manufacturing a press-bent pipe according to claim 2. The distance between the first corner processing band and the second connection processing band is longer than the distance between the third connection processing band and the fourth corner processing band,
The reverse bending zone is located between the second corner zone and the third corner zone,
The distance between the second corner processing zone and the reverse bending zone is shorter than the distance between the reverse bending zone and the third corner processing zone,
The first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, the first corner processing step, the third corner processing step, and the fourth corner The second corner portion processing step is performed after all of the portion processing step and the reverse bending step are completed.
4. The method of manufacturing a press-bent pipe according to claim 3. The distance between the first corner processing band and the second connection processing band is shorter than the distance between the third connection processing band and the fourth corner processing band,
The reverse bending zone is located between the second corner zone and the third corner zone,
The distance between the second corner processing zone and the reverse bending zone is longer than the distance between the reverse bending zone and the third corner processing zone,
The first connecting portion processing step, the second connecting portion processing step, the third connecting portion processing step, the first corner processing step, the second corner processing step, and the fourth corner The third corner portion processing step is performed after all of the portion processing step and the reverse bending step are completed.
4. The method of manufacturing a press-bent pipe according to claim 3. At the end of the one step of the corner processing steps, the concave bending along the reverse bending band is performed so that the inserted lower die or the upper die is separated from the plate material. the angle is set,
The method for manufacturing a press-bent tube according to any one of claims 2 to 4. In the second connecting portion processing step, the third connecting portion processing step, and each of the corner portion processing steps, the lower die is a female die, the upper die is a male punch,
In the first connecting portion processing step and the reverse bending step, the lower die is a male punch and the upper die is a female die,
The method for manufacturing a press-bent tube according to any one of claims 2 to 5. In the second connecting portion processing step, the third connecting portion processing step, and each of the corner portion processing steps, the lower die is a male punch, the upper die is a female die,
In the first connecting portion processing step and the reverse bending step, the lower die is a female die and the upper die is a male punch,
The method for manufacturing a press-bent tube according to any one of claims 2 to 5. A press-bent tube manufactured from a metal plate material,
the plate has a first edge and a second edge,
The plate member includes a folded portion located on the first edge side and a projecting portion located on the second edge side,
wherein the plate includes a plurality of mutually parallel working zones that are bent between the first edge and the second edge in a positional relationship along the plate;
The working zone is
a bent first connection zone located inside the press bend tube;
a bent second connection zone at least partially external to said press bend tube;
a bent third connection zone located at least partially external to said press bend tube;
including
By adjoining the second connecting portion processing band and the third connecting portion processing band, the plate material is partially formed into a tubular shape,
The folded portion is
a first region that connects the first end edge and the first connecting portion working zone inside the press bending pipe;
a second region connecting the first connecting portion working zone and the second connecting portion working zone inside the press bending tube;
including
a gap exists between the first region and the second region;
The projecting portion extends to connect the third connecting portion processing band and the second edge,
In the press bending tube, the protruding portion is partially positioned within the gap, so that the distance between the second connecting portion processing band and the third connecting portion processing band is widened. is configured to suppress the movement of
The processing band includes three or more corner processing bands in a portion of the plate material exposed to the outside of the press bending tube,
Each of the corner processing zones has a convexly bent shape when viewed from the outside of the press bending tube,
Press bent tube. The working band includes a reverse bending band in a portion of the plate material exposed to the outside of the press bending tube,
When viewed from the outside of the press bending tube, the reverse bending band has a concavely bent shape,
A press-bent tube according to claim 9.

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