JP4995049B2 - Pipe manufacturing method, manifold manufacturing method, and exhaust gas purification device manufacturing method - Google Patents

Description

  The present invention relates to a pipe manufacturing method, a manifold manufacturing method, and an exhaust gas purification device manufacturing method.

  Conventionally, in the process of heating the target location of the tubular body, and in the transverse direction of the tubular body, the outer mold with the annular thickening mold portion is arranged on the outer surface of the heated location, A method of performing a thickening step of applying a compressive force in the longitudinal direction of the tube and press-fitting it into a thickening mold part is disclosed (Patent Document 1).

Moreover, the manufacturing method of the welded steel pipe which welds the joint which formed the flat plate sheet in the cross-sectional shape by making it bend in the cross-sectional shape, and butt | matched the flat plate sheet is disclosed (patent document 2).
JP-A-11-156473 JP-A-5-161920

  According to the technique according to Patent Document 1 described above, although the thickness of the peripheral wall of the tubular body can be partially increased, this is not a method using a roller. Moreover, according to the technique which concerns on above-mentioned patent document 2, although a welded steel pipe is formed, the thickness of the surrounding wall of a welded steel pipe is not increased.

  The present invention has been made in view of the above circumstances, and a pipe manufacturing method capable of increasing the wall thickness of a pipe with a roller, a manifold manufacturing method using the increased wall thickness, and an exhaust gas purification device manufacturing method. It is an issue to provide.

  (1) A method of manufacturing a pipe according to aspect 1 includes a plurality of roller sets having a plurality of rollers facing a peripheral wall of a plastically deformable pipe having a pipe hole, and a plurality of sets in series along the axial length direction of the pipe. Using the straightening roller device arranged in parallel, the pipe is moved along the axial length direction from the upstream to the downstream with respect to the straightening roller device, and the peripheral wall of the pipe is straightened by the straightening roller device. The straightening roller device is configured when a part opposite to the center line of the pipe is a first part and a second part in a cross section of the pipe. In the plurality of roller sets, in the cross section of the pipe, the groove wall surface of the roller of the roller set on the downstream side is more than the groove wall surface of the roller of the roller set on the upstream side. The approaching amount approached in the radial direction of the pipe toward the center side is set such that the second part side> the first part side, and in the correction step, the second part of the pipe The thickness of the peripheral wall of the second part of the pipe is increased while the peripheral wall of the part is reduced in diameter in the radial direction of the pipe.

  According to this aspect, the amount of approach in the radial direction of the pipe is set such that the second part side> the first part side. For this reason, in the straightening process, the diameter of the peripheral wall of the second part of the pipe is reduced by the roller set of the straightening roller device in the radial direction of the pipe (the direction from the second part to the first part in the cross section of the pipe). Displace. This increases the thickness of the peripheral wall of the second part of the pipe.

(2) The manifold manufacturing method according to aspect 2 includes a pipe thickening step of forming a thickened portion obtained by thickening a plastically deformable pipe having a pipe hole in a cross section thereof, and the thickened portion is a bent outer periphery. A pipe bending step of bending the pipe to form a bent pipe, and a manifold manufacturing method including a step of assembling a plurality of bent pipes to the manifold body to form the manifold,
The pipe thickening step uses a straightening roller device in which a plurality of roller sets having a plurality of rollers facing the peripheral wall of the pipe are arranged in series along the axial length direction of the pipe. Is carried out along the axial length direction of the straightening roller device from the upstream to the downstream, and the straightening step of straightening the peripheral wall of the pipe with the straightening roller device is performed, When the portions opposite to each other with respect to the center line of the pipe are defined as the first portion and the second portion, in the plurality of roller sets constituting the correction roller device, in the cross section of the pipe, the upstream side About the approach amount in which the groove wall surface of the roller of the roller set downstream from the groove wall surface of the roller set approaches the center side of the pipe after correction in the radial direction of the pipe The second portion side> the first portion side relationship is set, and in the correction step, the peripheral wall of the second portion of the pipe is reduced in diameter in the radially inward direction of the pipe. The thickness of the peripheral wall of the second part is increased.

  According to this aspect, in the straightening process, the peripheral wall of the second part of the pipe is displaced in the radially inward direction of the pipe (the direction from the second part to the first part in the cross section of the pipe) by the roller set of the straightening roller device. The thickness of the peripheral wall of the second part of the pipe is increased.

(3) An exhaust gas purification device manufacturing method according to aspect 3 includes a pipe thickening step for forming a thickened portion obtained by thickening a plastically deformable pipe having a pipe hole in a cross section thereof, and the thickened portion. A pipe bending step for forming the bent pipe by bending the pipe so that the outer periphery is bent, and an assembly step for forming the exhaust gas purification device by assembling the bent pipe and the catalyst carrier to the purification device main body. And an exhaust gas purification device manufacturing method including:
The pipe thickening step uses a straightening roller device in which a plurality of roller sets having a plurality of rollers facing the peripheral wall of the pipe are arranged in series along the axial length direction of the pipe. Is carried out along the axial length direction of the straightening roller device from the upstream to the downstream, and the straightening step of straightening the peripheral wall of the pipe with the straightening roller device is performed, When the portions opposite to each other with respect to the center line of the pipe are defined as the first portion and the second portion, in the plurality of roller sets constituting the correction roller device, in the cross section of the pipe, the upstream side About the approach amount in which the groove wall surface of the roller of the roller set downstream from the groove wall surface of the roller set approaches the center side of the pipe after correction in the radial direction of the pipe The second portion side> the first portion side relationship is set, and in the correction step, the peripheral wall of the second portion of the pipe is reduced in diameter in the radially inward direction of the pipe. The thickness of the peripheral wall of the second part is increased.

  According to this aspect, in the straightening step, the peripheral wall of the second part of the pipe is displaced in the radial direction of the pipe by the roller set of the straightening roller device, and the thickness of the peripheral wall of the second part of the pipe is increased.

  According to the aspect 1, when the portions opposite to each other with respect to the center line of the pipe are the first portion and the second portion, the peripheral wall of the second portion of the pipe is in the radial direction (the second portion in the cross section of the pipe). To the first part), and the thickness of the peripheral wall of the second part of the pipe can be increased.

  According to aspect 2, in the pipe bending step, the pipe bending step is performed to form the bent pipe by bending the pipe so that the thickened portion of the peripheral wall of the pipe becomes a bent outer periphery. It is possible to reduce or avoid thinning of the bent pipe on the outer peripheral side. In addition, when the thickness reduction is excessive, the peripheral wall of the bent pipe may be damaged.

  According to the aspect 3, in the pipe bending process, the exhaust gas purification process is performed to form the bent pipe by bending the pipe so that the thickened portion of the peripheral wall of the pipe becomes a bent outer periphery. It is possible to reduce or avoid thinning defects on the bent outer peripheral side of the bent pipe of the apparatus. In addition, when the thickness reduction is excessive, the peripheral wall of the bent pipe may be damaged.

  Embodiments embodying the present invention will be described below.

(Embodiment 1)
FIG. 1A shows a cross section of a conventional pipe (before bending) that is not thickened. When the peripheral wall of the pipe 1 is bent so as to form a bent outer periphery and a bent inner periphery, a tensile stress extending in the axial length direction of the pipe 1 acts on the bent outer peripheral side of the peripheral wall of the pipe 1. For this reason, as shown to FIG. 1 (B), there exists a possibility that thickness reduction may arise in the bending outer periphery 10 side of the pipe 1. FIG. In some cases, when the degree of thinning is large, there is a possibility that a defect may occur on the bending outer periphery 10 side. In addition, since compressive stress acts on the bending inner periphery 11 side among the surrounding walls of the pipe 1, thickness reduction does not occur basically.

  Therefore, in this embodiment, as shown in FIG. 2 (A), in the stage before the pipe bending process for bending the pipe 1, the thickness of the peripheral wall of the pipe 1 is increased in advance so as to increase the thickness of the bent outer periphery 10 side. I will let you. As shown in FIG. 2 (B), when the pipe 1 having the increased thickness on the bent outer periphery 10 side of the peripheral wall is bent, the increased thickness is reduced, so that the pipe after the pipe bending step. The variation in the thickness of the peripheral wall of 1 is reduced.

  FIG. 3 schematically shows a change in wall thickness in the thickening step of increasing the thickness of the peripheral wall of the plastically deformable pipe 1 in the straightening step of the pipe 1. As shown in FIG. 3, the peripheral wall of the pipe 1 before the thickening step has a coaxial outer peripheral surface 13f and an inner peripheral surface 12f. The inner peripheral surface 12s and the outer peripheral surface 13s are eccentric while the peripheral wall of the pipe 1 after the thickening step is reduced in diameter in the radial direction. Thus, according to the pipe 1 after thickness increase, the surrounding wall by the side of the bending outer periphery 10 is locally thickened. Therefore, the inner diameter of the pipe 1 after the increase in thickness is reduced by reducing the inner diameter of the pipe 1 before the increase in thickness.

  The pipe 1 is formed by a roll forming method. In the roll forming method, a flat sheet is gradually bent by a guide roller arranged in series in the cross section thereof to be circular in a cross section (for example, a perfect circle shape or a pseudo perfect circle shape), and a butt joint, or The overlapped seam is fixed by welding.

  FIG. 4 schematically shows a straightening roller device 5 that performs a pipe thickening process (straightening process). As shown in FIG. 4, the correction roller device 5 includes an upstream roller group 2, a midstream roller group 3, and a downstream roller group 4 that face the outer peripheral surface of the pipe 1 along the axial length direction (arrow X1 direction) of the pipe 1. Are arranged side by side in series.

  The straightening roller device 5 performs a straightening process for straightening the shape of the welded pipe 1 and performs a pipe thickening process at the time of straightening. According to this embodiment, the shape of the peripheral wall of the pipe 1 is corrected while moving the pipe 1 from the upstream toward the downstream with respect to the correction roller device 5 along the axial length direction (arrow X1 direction). Implement the correction process. The pipe 1 is formed of a plastically deformable metal such as alloy steel such as stainless steel or carbon steel. Examples of the metal include ferrite, austenite, and pearlite that are easily plastically deformed. The straightening process may be cold working, or may be hot working or warm working to increase the plastic deformability of the pipe 1 as necessary. In the case of hot working or warm working, since the plastic deformability of the pipe 1 is increased, the restriction on the material of the pipe 1 is reduced. In the case of cold working, the material of the pipe 1 is preferably a ferrite type, austenite type, or pearlite type that can be easily plastically deformed.

  FIG. 3 schematically shows the change in the thickness in the thickness increasing process as described above. As shown in FIG. 3, the pipe 1 before being thickened is a cylindrical pipe whose inner peripheral surface 12 f and outer peripheral surface 13 f are defined by arcs. Of the peripheral wall of the pipe 1, in the cross section of the pipe 1, portions opposite to each other with respect to the center line Pc of the pipe 1 before thickening are defined as a first portion 16 and a second portion 17. The 1st site | part 16 becomes the bending inner periphery 11 side in a bending process. Since the 2nd site | part 17 becomes the bending outer periphery 10 side in a bending process, it becomes a thickened part thickened in a thickening process.

  As shown in FIG. 4, the upstream roller set 2 includes an upper first upstream roller 21 having a first groove wall surface 21c (the axial center is along the lateral direction) and a lower groove having a second groove wall surface 22c. And a second upstream roller 22 (the axis is along the lateral direction). The middle-stream roller set 3 includes an upper first middle-stream roller 31 having a first groove wall surface 31c (the axial center extends in the lateral direction) and a lower second middle-stream roller 32 having a second groove wall surface 32c (shaft). The core is along the lateral direction). The downstream roller set 4 includes an upper first downstream roller 41 having a first groove wall surface 41c (a shaft core is in a lateral direction) and a lower second downstream roller 42 having a second groove wall surface 42c (a shaft). The core is along the lateral direction).

  The first upstream roller 21 is rotatably supported on the base 21w. The second upstream roller 22 is rotatably supported by the base 22w. The first midstream roller 31 is rotatably supported on the base 31w. The second midstream roller 32 is rotatably supported by the base 32w. The first downstream roller 41 is rotatably supported by the base 41w. The second downstream roller 42 is rotatably supported on the base 42w.

  As shown in FIG. 5, the first groove wall surface 21c of the first upstream roller 21 has a substantially U-shaped cross section. The second groove wall surface 22c of the second upstream roller 22 has a substantially U-shaped cross section. The first groove wall surface 31c of the first intermediate flow roller 31 has a substantially U-shaped cross section. The second groove wall surface 32c of the second intermediate flow roller 32 has a substantially U-shaped cross section. The first groove wall surface 41c of the first downstream roller 41 has a substantially U-shaped cross section. The second groove wall surface 42c of the first downstream roller 42 has a substantially U-shaped cross section.

  Here, as shown in FIG. 6, the center of the circular locus defining the first groove wall surface 21c and the second groove wall surface 22c is defined as Pf. Let Ps be the center of a circular locus that defines the first groove wall surface 31c and the second groove wall surface 32c. Let Pt be the center of a circular locus defining the first groove wall surface 41c and the second groove wall surface 42c. The center of the circular locus moves from the second part 17 (bending outer peripheral side) of the pipe 1 toward the first part 16 (bending inner peripheral side) as it shifts to the center Pf, the center Ps, and the center Pt.

  According to the present embodiment, as the pipe 1 advances in the order of the upstream roller group 2, the midstream roller group 3, and the downstream roller group 4, the diameter of the peripheral wall of the pipe 1 is reduced in the cross section of the pipe 1. . In particular, the diameter of the second portion 17 which is a bent outer periphery of the peripheral wall of the pipe 1 progresses, and the center of the inner peripheral surface 12f of the pipe 1 is in the vicinity of the center Pf of the groove wall surface → the vicinity of Ps → the vicinity of Pt (FIG. 6). Move in the direction of arrow E1 in order.

  As described above, as the pipe 1 progresses to the upstream roller group 2, the midstream roller group 3, and the downstream roller group 4, the diameter of the second portion 17 of the peripheral wall of the pipe 1 mainly decreases in the radially inward direction. In the second part 17, the thickness increase proceeds.

  Further explanation will be added. That is, according to the present embodiment, as shown in FIG. 5, the position of one end 21 e of the first groove wall surface 21 c of the first upstream roller 21, the position of one end 31 e of the first groove wall surface 31 c of the first intermediate flow roller 31, The position of the one end 41e of the first groove wall surface 41c of the first downstream roller 41 is hardly changed in the extending direction of the axis P4 of the first downstream roller 41.

  In contrast, the position of the other end 21f of the first groove wall surface 21c of the first upstream roller 21, the position of the other end 31f of the first groove wall surface 31c of the first intermediate flow roller 31, and the first groove of the first downstream roller 41. The position of the other end 41f of the wall surface 41c is in the direction of the arrow E1 toward the center line Px (see FIG. 5) of the inner peripheral surface of the pipe 1 after thickening in a direction substantially parallel to the axis of the first upstream roller 21. It is displaced in the radial direction of the pipe 1. The reason for this is to reduce the diameter of the second portion 17 (the portion that becomes the bent outer periphery) of the peripheral wall of the pipe 1.

  Here, as can be understood from FIG. 6, when the first section 16 of the peripheral wall of the pipe 1 (the portion that becomes the bending inner periphery in the bending step) is visually recognized in the cross section of the pipe 1, The first groove wall surface 41c of the first downstream roller 41 of the downstream roller set 4 is closer to the center line Px side of the pipe 1 after correction in the radial direction of the pipe 1 than the first groove wall surface 21c of the upstream roller 21. Let the approached amount be ΔA1. ΔA1 is almost 0 or a minute amount.

  On the other hand, in the cross section of the pipe 1, the second portion 17 of the peripheral wall of the pipe 1 (the portion that becomes the bending outer periphery in the bending step) is more than the groove wall surface 21 c of the first upstream roller 21 of the upstream roller set 2. An approach amount in which the groove wall surface 41c of the first downstream roller 41 of the downstream roller set 4 is brought closer to the center line Px side of the pipe 1 after correction in the radial direction of the pipe 1 is denoted by ΔA2. At this time, ΔA2 (the second part 17 side) is set larger than ΔA1 (the first part 16 side) (ΔA2> ΔA1).

  In some cases, the aforementioned ΔA1 may be negative. The first groove wall surface 41c of the first downstream roller 41 of the downstream roller group 4 is closer to the center line Px side in the radial direction of the pipe 1 after correction than the first groove wall surface 21c of the first upstream roller 21 of the upstream roller group 2 It is a case where it is a little far away. Even in this case, the absolute value of ΔA2 is larger than the absolute value of ΔA1 in order to increase the thickness of the second portion 17 of the pipe 1 (the portion that becomes the bending outer periphery in the bending step).

  As can be understood from FIG. 5, the relationship between the lower second upstream roller 22 and the lower second downstream roller 42 is also the relationship between the upper first upstream roller 21 and the upper first downstream roller 41. The same is said.

  As a result, when the pipe 1 passes through the upstream roller group 2, the midstream roller group 3, and the downstream roller group 4 in this order, the peripheral wall of the pipe 1 is gradually displaced in the direction of arrow E1 (inward radial direction of the pipe 1). The direction of the arrow E1 means an inward radial direction from the second portion 17 (the portion serving as the bending outer periphery) toward the first portion 16 (the portion serving as the bending inner periphery) in the cross section of the pipe 1.

  For this reason, it is possible to displace the peripheral wall of the second portion 17 of the pipe 1 (the portion serving as the bending outer periphery) while reducing the diameter in the radial direction in the transverse cross section of the pipe 1. Thereby, as shown to FIG. 2 (A), the thickness of the 2nd site | part 17 of the surrounding wall of the pipe 1 can be thickened to the dimension t2. In addition, the thickness t1 of the 1st site | part 16 (part used as bending inner periphery) of the surrounding wall of the pipe 1 is not increased substantially. However, the present invention is not limited to this, and the first portion 16 (the portion serving as the inner periphery of bending) may be increased in thickness while maintaining the relationship of t2> t1.

  According to the present embodiment, as shown in FIG. 6, the pipe 1 is a welded pipe, and has a welded seam portion 19 extending along the longitudinal direction of the pipe 1. In the cross section of the pipe 1, the welded seam portion 19 avoids the maximum thickened portion 18 in the peripheral wall of the pipe 1 and is a portion other than the maximum thickened portion 18 (intermediate between the maximum thickened portion 18 and the first portion 16). Is set to In this case, the influence of the thickening phenomenon in the maximum thickened portion 18 is not easily propagated to the welded seam portion 19, and the protection against the welded seam portion 19 can be enhanced. Here, in the first portion 16 of the peripheral wall of the pipe 1, the variation in the thickness of the pipe 1 is smaller than that of the second portion 17 and is substantially absent.

  The weld seam 19 contacts the first groove wall surface 21 c of the upper first upstream roller 21. Similarly, the first groove wall surfaces 31c and 41c are also contacted. In this case, although depending on the hardness of the welded seam portion 19, it is expected that the first groove wall surfaces 21c, 31c, and 41c correct the vicinity of the welded seam portion 19. In some cases, the welded seam portion 19 may be brought into contact with the lower second groove wall surfaces 22c, 32c, and 42c instead of the upper first groove wall surfaces 21c, 31c, and 41c.

  According to the present embodiment, the upstream roller group 2, the midstream roller group 3, and the downstream roller group 4 are all driven roller systems that can idle, and are not driven by a drive motor. Therefore, it is suppressed that the peripheral wall of the pipe 1 is rolled by the upstream roller set 2, the midstream roller set 3, and the downstream roller set 4 along the longitudinal direction thereof. That is, it is reduced or avoided that the second portion 17 of the pipe 1 is rolled and thinned. However, in some cases, the upstream roller group 2, the middle-stream roller group 3, and the downstream roller group 4 may be driven by a drive motor. The correction roller device 5 is formed by arranging the upstream roller group 2, the middle-stream roller group 3, and the downstream roller group 4 in series. However, the present invention is not limited to this, and the upstream roller group 2 and the downstream roller group 4 are connected to each other. Although used, the midstream roller set 3 may be eliminated. Furthermore, the correction roller device 5 may be configured by arranging four or more sets of rollers and five or more sets of rollers in series.

(Embodiment 2)
FIG. 7 shows a second embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. According to the present embodiment, the axis of the first downstream roller 41 and the axis of the second downstream roller 42 are not in the horizontal direction but in the vertical direction (vertical direction). The upstream roller set 2 includes a right first upstream roller 21 having a first groove wall surface 21c and a left second upstream roller 22 having a second groove wall surface 22c. The midstream roller set 3 includes a right first midstream roller 31 having a first groove wall surface 31c and a left second midstream roller 32 having a second groove wall surface 32c. The downstream roller set 4 includes a right first downstream roller 41 having a first groove wall surface 41c and a left second downstream roller 42 having a second groove wall surface 42c.

(Embodiment 3)
FIG. 8 shows a third embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. However, according to this embodiment, the direction and number of rollers are different. That is, as shown in FIG. 8, the upstream roller set 2 includes a first upstream roller 21 having a first groove wall surface 21c (the axis is along the vertical direction) and a second upstream surface having a second groove wall surface 22c. The roller 22 (the axial center is along the diagonal direction) and the third upstream roller 23 having the third groove wall surface 23c are provided (the axial core is along the diagonally opposite direction).

  The midstream roller assembly 3 includes a first midstream roller 31 having a first groove wall surface 31c having a substantially U-shaped cross section, a second midstream roller 32 having a second groove wall surface 32c having a substantially U-shaped cross section, and a first U-shaped roller having a substantially U-shaped cross section. And a third midstream roller 33 having a three-groove wall surface 33c. The downstream roller set 4 includes a first downstream roller 41 having a first groove wall surface 41c having a substantially U shape in cross section, a second downstream roller 42 having a second groove wall surface 42c having a substantially U shape in cross section, and a first U roller having a substantially U shape in cross section. And a third downstream roller 43 having a three-groove wall surface 43c.

  When viewed from the cross section of the pipe 1, the downstream roller 41 of the downstream roller set 4 is located at the first portion 16 (bending inner peripheral side) of the pipe 1 rather than the first groove wall surface 21 c of the upstream roller 21 of the upstream roller set 2. An approach amount in which the first groove wall surface 41c is brought closer to the center line Px of the pipe 1 after the thickness increase in the radial direction of the pipe 1 is denoted by ΔA1. ΔA1 is 0 or a very small amount.

  Further, when visually checking in the cross section of the pipe 1, the second portion 17 (bending outer peripheral side) of the pipe 1 has a lower roller set 4 than the groove wall surfaces 22 c and 23 c of the upstream rollers 22 and 23 of the upstream roller set 2. An approach amount in which the groove wall surfaces 42c and 43c of the downstream rollers 42 and 43 are made to approach in the radial direction of the pipe 1 toward the center line Px of the pipe 1 after thickening is defined as ΔA2. At this time, ΔA2 (the second part 17 side) is set larger than ΔA1 (the first part 16 side) (ΔA2> ΔA1).

  As a result, as in the case of the first embodiment, when the pipe 1 passes through the upstream roller group 2, the midstream roller group 3, and the downstream roller group 4 in this order, the peripheral wall of the second portion 17 of the pipe 1 is crossed by the cross section of the pipe 1. The diameter can be reduced in the radial direction. Thereby, thickness t2 of the surrounding wall of the 2nd site | part 17 of the pipe 1 can be increased. In this case, the thickness t1 of the peripheral wall of the first portion 16 of the pipe 1 is not substantially increased.

  After performing the correction process as described above, a cutting process for cutting the pipe 1 into a predetermined length is performed. Then, the bending process of the pipe 1 is implemented. In the bending step, the increased second portion 17 is set as the outer peripheral side of bending. Although compressive stress is generated in the length direction of the pipe 1 on the inner side of the bend, tensile stress is likely to be generated in the length direction of the pipe 1 on the outer periphery of the bend. Here, since the thickness of the 2nd site | part 17 is increased, it is suppressed that the excessive thickness reduction generate | occur | produces in the 2nd site | part 17 (bending outer peripheral side). In addition, when it is not necessary to cut | disconnect the pipe 1, you may decide to implement the bending process of the pipe 1 after implementing a correction process.

(Embodiment 4)
Since this embodiment has basically the same configuration and operational effects as the third embodiment, FIG. 8 is applied mutatis mutandis. According to the third embodiment shown in FIG. 8, the first upstream roller 21. First middle-stream roller 31. The axis of the first downstream roller 41 is along the vertical direction (vertical direction). In this regard, according to this embodiment, the first upstream roller 21. First middle-stream roller 31. The axis of the first downstream roller 41 is not in the vertical direction (up and down direction) but in the horizontal direction (left and right direction).

(Embodiment 5)
FIG. 9 shows a fifth embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment. As shown in FIG. 9, the pipe 1 is a welded pipe having a welded seam portion 19 extending along the longitudinal direction of the pipe 1. Since the weld seam 19 is rapidly cooled, the vicinity of the weld seam 19 may be hardened depending on the material of the pipe 1 or the weld seam 19. According to the present embodiment, the weld seam portion 19 of the pipe 1 does not contact the groove wall surfaces 21c, 22c, 31c, 32c, 41c, 42c of the rollers 21, 22, 31, 32, 41, 42 (non-contact position). ) Is set. As described above, since the weld seam 19 is set at a position that does not contact the groove wall surfaces 21c, 22c, 31c, 32c, 41c, and 42c, damage to the groove wall surfaces 21c, 22c, 31c, 32c, 41c, and 42c is reduced. Or be avoided. Further, the weld seam 19 is not greatly affected. The position where the weld seam 19 is formed in the circumferential direction of the pipe 1 is a portion that is not on the outer periphery of the bending where the tensile stress acts but on the inner periphery of the bending where the compressive stress acts when the pipe 1 is bent. . For this reason, it is not necessary to apply an excessive tensile stress to the welded seam 19, and the protection of the welded seam 19 can be improved.

(Embodiment 6)
The present embodiment has basically the same configuration and operational effects as the above-described first to fifth embodiments. According to this embodiment, the pipe 1 is formed of a seamless pipe and does not have the welded seam portion 19.

(Embodiment 7)
The present embodiment has basically the same configuration and operational effects as the third embodiment described above. According to this embodiment, the bending process of the pipe 1 is performed after the above-described correction process, and the cutting process of cutting the bent pipe into a predetermined length is performed after the bending process.

(Embodiment 8)
FIG. 10 shows an eighth embodiment. The present embodiment has basically the same configuration and operational effects as the first embodiment described above. According to the present embodiment, as shown in FIG. 10, the cylinder device 22 x is provided on the base 22 w of the second upstream roller 22. A cylinder device 32 x is provided on the base 32 w of the second intermediate flow roller 32. A cylinder device 42 x is provided on the base 42 w of the second downstream roller 42.

  Here, base 22w, base 32w. The position of the base 42 w can be adjusted in the direction of the arrow Y 1 along the direction perpendicular to the axis of the pipe 1, that is, toward the pipe 1. Base 22w, base 32w. If the base 42w is moved in the direction of the arrow Y1 (the direction perpendicular to the axis of the pipe 1), as described above, the thickening of the peripheral wall of the pipe 1 can be executed. When the thickness is not increased, the base 22w, the base 32w. The base 42w is retracted in the direction of the arrow Y2 along the direction perpendicular to the axis of the pipe 1.

(Embodiment 9)
FIG. 11 shows a ninth embodiment. The present embodiment has basically the same configuration and operational effects as the third embodiment. As shown in FIG. 11, the present embodiment is applied to an exhaust gas exhaust manifold 7 mounted on a vehicle or the like together with an internal combustion engine. The manifold 7 is formed by assembling the bending pipe 71 to the manifold main body 70 by assembling means such as welding. The bent pipe 71 includes a metal outer pipe 72 and a metal inner pipe 73 inserted almost coaxially into the outer pipe 72 so as to form a heat insulating space 74 between the outer pipe 72. ing.

  In order to reduce the heat transfer amount of the exhaust gas passing through the pipe hole 73w of the inner pipe 73, the wall thickness of the inner pipe 73 is set to be thinner than the wall thickness of the outer pipe 72, for example, 0.2 to 2 mm, It is set to 0.4-1 mm. Therefore, when the inner pipe 73 is formed by bending, excessive thinning or chipping may occur when the bending degree is high on the outer peripheral side of the inner wall of the inner pipe 73 where tensile stress acts. .

  Therefore, according to the present embodiment, as in each of the embodiments described above, the peripheral wall of the second portion 17 (bending outer peripheral side) of the inner pipe 73 is displaced radially inward, and the second portion 17 (bending of the inner pipe 73 is bent). The thickness of the peripheral wall on the outer peripheral side is partially increased. Thereafter, the inner pipe 73 is bent so that the thickened second portion 17 has a bent outer periphery. Further, the outer pipe 72 is also bent. Since the outer pipe 72 has a large wall thickness, even if it is bent and thinning occurs, there is no trouble such as chipping. Therefore, the outer pipe 72 may not be subjected to a thickening process. However, the thickening process may be performed on the outer pipe 72 as necessary. A bent pipe 71 is formed by inserting the inner pipe 73 thus formed into the outer pipe 72 substantially coaxially. The bent pipe 71 is assembled to the manifold main body 70 by welding or bolt fastening to form the manifold 7.

(Embodiment 10)
FIG. 12 shows the tenth embodiment. The present embodiment has basically the same configuration and operational effects as the third embodiment. According to this embodiment, the bent pipe 81 and the catalyst carrier are assembled to the converter 80 (purification device body) to form the catalytic converter device 8 (exhaust gas purification device). The bent pipe 81 has a bent portion 81a having a large bending angle of 40 degrees or more, and is connected to the main muffler and the sub muffler. In this case, in the pipe bending step, a metal pipe that can be plastically deformed is formed so as to form a bent outer periphery and a bent inner periphery, thereby forming a bent pipe 81 having a bent portion 81a. Before the pipe bending step, the second part of the pipe 81 is displaced in the radial direction while the peripheral wall of the second part (bending outer peripheral side) of the pipe 81 is displaced in the radial direction as in the above-described embodiments. The thickness of the peripheral wall on the bending outer periphery side is partially increased.

(Other)
The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not departing from the gist.

(A) is a figure which shows the cross section of the conventional pipe, (A) is a figure which shows the cross section of the state which bent the conventional pipe. (A) is a figure which shows the cross section of the pipe of embodiment, (A) is a figure which shows the cross section of the state which bent the pipe of embodiment. It is a figure which shows the cross section of the thickening process of the pipe of embodiment. It is a figure which shows a correction | amendment roller apparatus typically. It is a figure which shows typically the state which is thickening a pipe using the correction | amendment roller apparatus. It is a figure which shows the relationship between a welding seam part and a roller while showing typically the state which is increasing the pipe thickness using the correction | amendment roller apparatus. It is a figure which shows typically the state which is thickening a pipe using the correction roller apparatus concerning other embodiment. It is a figure which shows typically the state which is thickening a pipe using the correction roller apparatus concerning another embodiment. It is a figure which shows typically the state which is thickening a pipe using the correction roller apparatus concerning another embodiment. It is a figure which shows a correction | amendment roller apparatus typically concerning different embodiment. It is a perspective view which shows the manifold for exhaust-gas discharge | emission. 1 is a perspective view showing an exhaust gas purification device mounted on a vehicle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 is a pipe, 10 is a bending outer periphery, 11 is a bending inner periphery, 14 is a pipe hole, 16 is a 1st site | part, 17 is a 2nd site | part, 18 is the largest thickness part, 19 is a welding seam part, 2 is an upstream roller apparatus , 21 is a first upstream roller, 22 is a second upstream roller, 3 is a midstream roller device, 31 is a first midstream roller, 32 is a second midstream roller, 4 is a downstream roller device, 41 is a first downstream roller, and 42 is Second downstream roller, 5 is a correction roller device, 7 is a manifold, 70 is a manifold body, 71 is a curved pipe, 72 is an outer pipe, 73 is an inner pipe, 8 is a converter device (exhaust gas purification device), and 80 is a converter (Purification device main body), 81 indicates a bent pipe.

Claims (8)

Using a correction roller device in which a plurality of roller sets having a plurality of rollers facing the peripheral wall of a plastically deformable pipe having a pipe hole are arranged in series along the axial length direction of the pipe,
A method of performing a correction step of correcting the peripheral wall of the pipe by the correction roller device while moving the pipe from the upstream to the downstream along the axial length direction of the pipe. ,
In the cross section of the pipe, when the portions opposite to each other with respect to the center line of the pipe as the first portion and the second portion,
In the plurality of roller sets constituting the correction roller device,
In the cross section of the pipe, the groove wall surface of the roller of the roller set on the downstream side is directed toward the center side of the pipe after correction, rather than the groove wall surface of the roller of the roller set on the upstream side. For the approaching amount approached in the radial direction, the relation of the second part side> the first part side is set,
In the straightening process, the thickness of the peripheral wall of the second part of the pipe is increased while the peripheral wall of the second part of the pipe is reduced in diameter in the radial direction of the pipe. Method.   In Claim 1, after performing the said correction process, or after performing the cutting process which cut | disconnects the said pipe to predetermined length after the said correction process, the bending process of the said pipe is implemented, In the said bending process The method of manufacturing a pipe, characterized in that the increased thickness of the second part is a bent outer peripheral side, and the first part is a bent inner peripheral side.   3. The pipe according to claim 1, wherein the pipe is a welded pipe having a welded seam, and the welded seam is set so as to avoid a maximum wall thickness portion of the pipe in a cross section of the pipe. A method of manufacturing a pipe characterized by the above.   4. The method for manufacturing a pipe according to claim 3, wherein the weld seam of the pipe is set at a position where it does not hit the roller.   The method for manufacturing a pipe according to claim 3, wherein the weld seam portion of the pipe hits the roller and is corrected. A pipe thickening step for forming a thickened part of a plastically deformable pipe having a pipe hole in the cross section thereof; and bending the pipe so that the thickened part becomes a bent outer periphery. A manifold manufacturing method including a pipe bending step of forming a forming pipe, and an assembly step of forming a manifold by assembling a plurality of the bending pipes to a manifold body,
The pipe thickening step
Using a correction roller device in which a plurality of sets of rollers having a plurality of rollers facing the peripheral wall of the pipe are arranged in series along the axial length direction of the pipe,
Performing a correction step of correcting the peripheral wall of the pipe by the correction roller device while moving the pipe from upstream to downstream with respect to the correction roller device along the axial length direction of the pipe;
In the cross section of the pipe, when the portions opposite to each other with respect to the center line of the pipe as the first portion and the second portion,
In a plurality of roller sets constituting the straightening roller device,
In the cross section of the pipe, the groove wall surface of the roller of the roller set on the downstream side is directed toward the center side of the pipe after correction, rather than the groove wall surface of the roller of the roller set on the upstream side. For the approaching amount approached in the radial direction, the relation of the second part side> the first part side is set,
In the straightening step, the thickness of the peripheral wall of the second part of the pipe is increased while reducing the diameter of the peripheral wall of the second part of the pipe in the radially inward direction of the pipe. .   The bent pipe according to claim 6, wherein the bent pipe includes an outer pipe and an inner pipe inserted into the outer pipe so as to form a heat insulation space between the outer pipe and the pipe. Is carried out on the inner pipe. A pipe thickening step for forming a thickened part of a plastically deformable pipe having a pipe hole in the cross section thereof; and bending the pipe so that the thickened part becomes a bent outer periphery. An exhaust gas purification device manufacturing method including a pipe bending step of forming a formed pipe, and an assembly step of forming the exhaust gas purification device by assembling the bent pipe and the catalyst carrier to the purification device main body,
The pipe thickening step
Using a correction roller device in which a plurality of sets of rollers having a plurality of rollers facing the peripheral wall of the pipe are arranged in series along the axial length direction of the pipe,
Performing a correcting step of correcting the peripheral wall of the pipe by the correcting roller device while moving the pipe from the upstream to the downstream along the axial length direction of the pipe;
In the cross section of the pipe, when the portions opposite to each other with respect to the center line of the pipe as the first portion and the second portion,
In a plurality of roller sets constituting the straightening roller device,
In the cross section of the pipe, the groove wall surface of the roller of the roller set on the downstream side is directed toward the center side of the pipe after correction, rather than the groove wall surface of the roller of the roller set on the upstream side. For the approaching amount approached in the radial direction, the relation of the second part side> the first part side is set,
In the correction step, the exhaust gas purification is characterized by increasing the thickness of the peripheral wall of the second part of the pipe while reducing the diameter of the peripheral wall of the second part of the pipe in the radially inward direction of the pipe. Device manufacturing method.

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