JP7456614B2 - Straightening method and device for metal cylindrical tubes - Google Patents

Description

The present invention relates to a straightening method and a straightening device for straightening a warpage that occurs in a metal cylindrical tube formed into a circular cross section by bending a flat metal plate into a cylindrical shape and then joining the abutted portions.

As a manufacturing method for a metal cylindrical tube, after bending a workpiece W, which is a rectangular flat metal plate shown in FIG. 6(A), into a cylindrical shape as shown in FIG. 6(B), the two end faces facing each other in the circumferential direction are butted. A method of joining the portion W1 is known. As shown in Figure (C), the abutting portion W1 of the workpiece W bent into a cylindrical shape is conveyed along the axial direction in a state facing a joining tool such as a welding torch. are joined through.

In the workpiece W formed into a metal cylindrical tube with a circular cross section in this way, the temperature of the abutting portion W1 rises to a high temperature once during joining and then decreases to room temperature, while the temperature of the other portions other than the abutting portion W1 hardly changes. Only the abutted portion W1 contracts, and as shown in FIG. 2D, the abutted portion W1 warps inwardly, resulting in a decrease in roundness and straightness.

Therefore, in order to correct the warpage that has occurred in the metal cylindrical tube, several sets of drum-shaped rollers are installed inside a hollow rotating body that rotates around the feed axis of the metal cylindrical tube, so that their rotating axes intersect the feed axis at a certain angle. When the metal cylindrical tube is supported in an arrayed state and freely rotatable and fed into the hollow rotating body along the feed axis, the drum-shaped roller rotates around the metal cylindrical tube due to the feeding force. A correction method and a correction device that perform orbital movement have been proposed (see, for example, Patent Document 1).

With this configuration, when the metal cylindrical tube is fed into the hollow rotating body along the feed axis, the drum-shaped roller receives the feeding force and rotates around the metal cylindrical tube at the same time, causing the metal Bending force and crushing force are applied to the surface of the cylindrical tube, and in the process of continuously transporting a long coiled metal cylindrical tube on an automatic line, it is possible to prevent damage such as scratches and roller marks on the metal cylindrical tube. It is said that it is possible to perform correction with high precision without giving any damage.

In conventional metal cylindrical pipe straightening methods and straightening apparatuses, a drum-shaped roller is generally used, not limited to the configuration described in Patent Document 1.
Japanese Patent Application Publication No. 05-000325

However, the drum-shaped rollers used in conventional metal cylindrical tube straightening methods and straightening devices must have a contact surface with the metal cylindrical tube with an arc of a size suitable for the outer diameter of the metal cylindrical tube. Not only does the design require technology and time, which increases costs, but it also requires preparing a device equipped with drum-shaped rollers whose contact surfaces are formed by arcs of individual sizes for each outer diameter of the metal cylindrical tube. There is an unavoidable problem.

In addition, the configuration described in Patent Document 1 rotates and revolves a large number of drum-shaped rollers by the feeding force applied to the inside of the hollow rotating body of the metal cylindrical tube, and the metal cylindrical tube is moved inside the hollow rotating body. In order to feed the metal tube forward, it is necessary to apply a large driving force to the metal tube along the feed axis. For this reason, not only does a large-capacity drive system become necessary, leading to an increase in the size of the device, but also there is a possibility that the surface of the metal cylindrical tube may be damaged when the propulsion force is applied.

It is an object of the present invention to eliminate the need for drum-shaped rollers, reduce design costs, reduce the size of the device, and straighten the warped metal cylindrical tube without damaging the surface of the metal cylindrical tube. It is an object of the present invention to provide a method and apparatus for straightening a metal cylindrical tube, which can improve circularity and straightness.

The applicant has proposed that, at each of three or more positions in the circumferential direction on a cross section of a metal cylindrical tube that advances in the direction of the feed axis, two points, front and back in the feed axis direction, having a phase difference in the circumferential direction, with respect to the feed axis direction. It has been discovered that by repeatedly applying pressing force from a roller having a rotation axis inclined at a predetermined angle, it is possible to correct the warpage of a metal cylindrical tube without using a drum-shaped roller.

The method for straightening a metal cylindrical tube of the present invention involves moving a set of rollers in which two rollers are spaced apart around a rotating shaft inclined with respect to the feed axis direction of the metal cylindrical tube in the circumferential direction of the metal cylindrical tube. Three or more sets of rollers are arranged in one stage along the feed axis direction of the metal cylindrical tube, with three or more roller sets arranged at intervals and at the same location in the feed axis direction of the metal cylindrical tube, and the peripheral surface of each roller is While in pressure contact with the surface, the portion of the circumferential surface of each roller that contacts the surface of the metal cylindrical tube rotates each roller in a direction toward the front in the direction of the feed axis of the metal cylindrical tube.

The straightening device for metal cylindrical tubes of the present invention includes a set of rollers in which two rollers are arranged at intervals around a rotating shaft inclined with respect to the feed axis direction of the metal cylindrical tube, in the circumferential direction of the metal cylindrical tube. A plurality of roller sets arranged in multiple stages along the feed axis direction of the metal cylindrical tube, with three or more sets arranged at intervals and at the same location in the feed axis direction of the metal cylindrical tube, and metal rollers on the circumferential surface of each roller. The driving mechanism includes a drive mechanism whose portion that presses against the surface of the cylindrical tube supplies each roller with rotation in a forward direction in the direction of the feed axis of the metal cylindrical tube.

When a metal cylindrical tube is inserted between three or more pairs of rollers in the first roller set, the rotation of each roller in the first roller set causes the metal cylindrical tube to move along the feed axis direction, passing between three or more pairs of rollers in the second and subsequent roller sets in sequence. As the metal cylindrical tube passes through each roller set, at least three points in the circumferential direction on the surface of the metal cylindrical tube in each cross section are simultaneously subjected to pressing forces from the rollers at two points, front and rear, in the feed axis direction, which have a phase difference in the circumferential direction. This pressing force acts over the entire length of the metal cylindrical tube, making the internal stress of the metal cylindrical tube uniform and correcting the warping that had occurred in the metal cylindrical tube, improving the roundness and straightness of the metal cylindrical tube.

In this configuration, the set of rollers includes a rotating shaft that is inclined with respect to the feed axis direction of the metal cylindrical tube and has two rollers fixed on the same axis with an interval, and the drive mechanism rotates. Each roller set is equipped with a pinion gear coaxially fixed to the shaft, a ring gear whose internal teeth mesh with the pinion gear, and a drive gear whose internal teeth mesh with the external teeth of the ring gear. The drive shaft may include a drive source fixed to the drive shaft.

Rotation generated by a single drive source is transmitted via a drive gear, a ring gear, and a pinion gear to the respective rotating shafts of three or more sets of rollers each of a plurality of roller sets is provided with, and a plurality of roller sets are formed. It is possible to rotate all the rollers provided in the same direction and at the same speed.

Each roller set shall be equipped with a frame that pivotally supports the rotational shaft of at least one set of rollers so as to be able to move toward and away from the rotational shaft of the other two sets of rollers, and that pivotally supports a ring gear. be able to.

Each roller set can be configured independently from each other, and the number of stages of roller sets to be arranged in the metal cylindrical tube straightening apparatus can be easily changed.

The frame of each roller set can support a support roller whose peripheral surface abuts radially against the ring gear at a position in phase with the meshing position of the pinion gear.

The ring gear can be reliably supported in a small space, and each roller set can be configured in a small size.

The pinion gear can also have a diameter smaller than each roller and be arranged between the rollers on the rotating shaft.

By minimizing the length of the rotating shaft, each roller set can be configured to be compact in the direction of the feed axis of the metal cylindrical tube.

According to this invention, it is possible to reduce the design cost and downsize the device by eliminating the need for a drum-shaped roller, and also to correct the warp of the metal cylindrical tube without damaging the surface of the metal cylindrical tube, making it perfectly round. It is possible to improve the degree and straightness.

(A) to (C) are a plan view, a front view, and a side view of a metal cylindrical tube straightening device according to an embodiment of the present invention. It is a side view which shows the arrangement|positioning state of each component in the roller set which the same correction apparatus is equipped with. (A) and (B) are a plan sectional view and a front sectional view of main parts explaining the arrangement state of the assembled rollers in the same roller set. It is a figure explaining the straightening action of the metal cylindrical tube by the set roller in the same straightening device. (A) and (B) are side views showing the arrangement of each component in a roller set included in a metal cylindrical tube straightening device according to another embodiment of the present invention. (A) to (D) are diagrams illustrating the manufacturing process and the state of warpage of the metal cylindrical tube.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A metal cylindrical tube straightening method and straightening device according to an embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1(A) to 1(C), a straightening device 100 according to an embodiment of the present invention includes, as an example, five roller sets 10, A geared motor 20 is provided. Each roller set 10 is arranged on the base 70 along the feed axis direction D1 of the metal cylindrical tube 200, and is housed in a U-shaped frame 11 that is open toward the upper side, the front side, and the back side. As an example, three sets of assembled rollers 30, three sets of support rollers 40, and a ring gear 50 are arranged, and a drive gear 60 is provided outside the frame 11. The feed axis direction D1 is a direction that coincides with the axial direction of the metal cylindrical tube 200 without warpage.

The geared motor 20 is an example of a drive source of the present invention, and outputs rotation to the drive shaft 21 via the gear section 22. The drive gear 60 is coaxially fixed to the drive shaft 21 of the geared motor 20. The frame 11 is formed with a hole 12 through which the metal cylindrical tube 200 passes. Each support roller 40 has two rollers 42A and 42B coaxially fixed to a rotating shaft 41 with an interval provided therebetween.

In addition, in FIG. 1(A), among the three sets of assembled rollers 30, only one set of assembled rollers 30 located at the upper part is shown, and the two sets of assembled rollers 30 located at the lower part are omitted. In (B), three sets of roller sets 30 are omitted.

As shown in FIG. 2, in each roller set 10, three sets of roller sets 30, three sets of support rollers 40, and a ring gear 50 are rotatably held. External teeth 51 of the ring gear 50 mesh with a drive gear 60 fixed to the drive shaft 21. Each set of rollers 30 includes two rollers 32A and 32B coaxially fixed to a rotating shaft 31 with an interval, and one pinion gear 33 coaxially fixed between the rollers 32A and 32B. ing. Each of the three roller sets 30 is held at a position where the circumferential surfaces of the rollers 32A, 32B are pressed against the surface of the metal cylindrical tube 200 at three equally spaced locations in the circumferential direction of the metal cylindrical tube 200. The pinion gear 33 is disposed between the two rollers 32A and 32B, and meshes with the internal teeth 52 of the ring gear 50.

As an example, the two rollers 32A and 32B are flat rollers each having a diameter of 58 mm and a width of 16 mm, and a distance of 28 mm is provided between them. The rollers 32A and 32B can also have slightly concave peripheral surfaces.

Each of the rollers 42A and 42B of the three sets of support rollers 40 (roller 42B does not appear in FIG. 2) has a circumferential surface on the circumferential surface of a collar portion 53 formed on both sides of the ring gear 50 over the entire circumference. They abut at three equally spaced locations, and the mutually opposing side surfaces contact the side surfaces of the external teeth 51 of the ring gear 50.

The ring gear 50 is supported by three sets of support rollers 40 at a fixed position within the roller set 10 . Each of the three sets of support rollers 40 is arranged at the same phase position as the three sets of roller sets 30 on the side facing each of the three sets of roller sets 30 with the metal cylindrical tube 200 interposed therebetween. Since the respective rollers 42A and 42B of the support roller 40 are located in the direction in which the pressing force from the respective rollers 32A and 32B of the three sets of roller sets 30 acts on the metal cylindrical tube 200, each roller set 10 of the ring gear 50 The position at is maintained reliably.

The geared motor 20, pinion gear 33, support roller 40, ring gear 50, and drive gear 60 correspond to the drive mechanism of the present invention.

In the straightening device 100, the five roller sets 10 are independent from each other. Therefore, one or more roller sets 10 can be removed from the base 70 to provide the minimum necessary number of roller sets 10. Furthermore, the base 70 and drive shaft 21 can be extended to add one or more roller sets 10.

When the geared motor 20 is driven to rotate the drive gear 60 along with the drive shaft 21 in the direction of the arrow RA, the ring gear 50 rotates in the direction of the arrow RB, and the rollers 32A and 32B rotate together with the pinion gear 33 in the direction of the arrow RC. The direction of the arrow RC is the feed axis direction D1 of the metal cylindrical tube 200 (see FIG. 1(A)), where the portions of the peripheral surfaces of the rollers 32A and 32B that come into pressure contact with the metal cylindrical tube 200 are in the direction toward the front of the paper in FIG. The direction is towards the front. Therefore, by rotating the rollers 32A and 32B in the direction of the arrow RC, the metal cylindrical tube 200 is conveyed toward the front in the feed axis direction D1.

As shown in FIG. 3(A), in each roller set 10, the roller set 30 is rotatably held with the rotating shaft 31 tilted by a predetermined angle θ with respect to the feed axis direction D1 of the metal cylindrical tube 200. ing. For this purpose, vertical members 11A and 11B of the frame 11 facing each other are provided with self-aligning bearings 13. The self-aligning bearing 13 supports a rotating shaft 31 that is inclined at a predetermined angle θ with respect to the feed axis direction D1.

Note that FIG. 3(A) is a plan cross-sectional view at the position of one set of roller sets 30 located at the top of the three sets of roller sets 30 in each roller set 10. Regarding the other two sets of rollers 30, the rotating shaft 31 is set at a predetermined angle with respect to the feed axis direction D1 in the cross section seen from the normal direction of the metal cylindrical tube 200 passing through the axial center position of the rotating shaft 31. It is tilted by θ. The angle θ is an angle of 5 to 6 degrees, and is set to 5.57 degrees as an example.

Further, when the pinion gear 33 and the external teeth 51 of the ring gear 50 are spur gears, the teeth of the pinion gear 33 partially mesh with the teeth of the external teeth 51 at an angle θ. Therefore, it is preferable that the pinion gear 33 and the external teeth 51 of the ring gear 50 are inclined at an angle θ.

As shown in FIG. 3B, the self-aligning bearing 13 supporting at least the topmost pair of rollers 30 among the three pairs of rollers 30 in each roller set 10 is clamped vertically by an adjustment screw 131 and an elastic body 132 within the vertical members 11A and 11B. By loosening the lock nut 133 and rotating the adjustment screw 131 forward or backward, the rotating shaft 31 moves vertically together with the self-aligning bearing 13. The topmost pair of rollers 30 can be moved toward or away from the other two pairs of rollers 30, and the pressing force acting on the surface of the metal cylindrical tube 200 from the rollers 32A and 32B of the three pairs of rollers 30 can be adjusted.

Note that the elastic body 132 can be made of any material such as a spring or urethane rubber. Moreover, not only the one set of roller sets 30 located at the top, but also all three sets of roller sets 30 can be pivoted as shown in FIG. 3(B).

The straightening method of the present invention implemented in the straightening device 100 configured as described above includes two rollers 32A and 32B arranged at a predetermined interval around a rotating shaft 31 inclined at an angle θ with respect to the feed axis direction D1. The roller sets 10 are arranged in five stages along the feed axis direction D1, and three sets of roller sets 30 are arranged at equal intervals in the circumferential direction of the metal cylindrical tube 200 and at the same location in the feed axis direction D1. With the circumferential surfaces of the rollers 32A, 32B in pressure contact with the surface of the metal cylindrical tube 200, the portions of the circumferential surfaces of the rollers 32A, 32B that contact the surface of the metal cylindrical tube 200 move toward the feed axis direction D1. Rotate.

When the metal cylindrical tube 200 is inserted between the three sets of rollers 30 in the first stage roller set 10, the metal cylindrical tube 200 is rotated by the rotation of the rollers 32A and 32B arranged in the first stage roller set 10. It progresses along the direction D1 so as to pass sequentially between the three sets of roller sets 30 in the second and subsequent roller sets 10.

As shown in FIG. 4, when the metal cylindrical tube 200 passes through each roller set 10, the surface of the metal cylindrical tube 200 is moved in the circumferential direction at each of three positions P1 to P3 in the circumferential direction in each cross section CS. Pressure forces are simultaneously applied from the circumferential surfaces of the rollers 32A and 32B at two points, front and rear, in the feed axis direction D1 having a phase difference of .

In the cross section CS, at position P1, rollers 32A, Pressure forces F1A and F1B are applied from the circumferential surface of 32B. In addition, at position P2, the cross section CS has a roller at two points, front and back, in the feed axis direction D1, which have a phase difference in the circumferential direction on a direction RA2 inclined at an angle θ with respect to a direction AD2 parallel to the feed axis direction D1. Pressure forces F2A and F2B are applied from the circumferential surfaces of 32A and 32B. Further, at position P3, the cross section CS shows that the roller is located at two points in front and rear of the feed axis direction D1 having a phase difference in the circumferential direction on a direction RA3 inclined at an angle θ with respect to a direction AD3 parallel to the feed axis direction D1. Pressure forces F3A and F3B are applied from the circumferential surfaces of 32A and 32B. These pressing forces F1A, F1B, F2A, F2B, F3A, and F3B act simultaneously on the cross section CS of the metal cylindrical tube 200 in each roller set 10.

When the pressing forces F1A, F1B, F2A, F2B, F3A, and F3B are repeatedly applied to the surface of the metal cylindrical tube 200 conveyed along the feed axis direction D1 over the entire length by the five roller sets 10, the metal cylindrical tube In 200, the internal stress is made uniform by slightly shrinking the tube, and as a result, the warpage that occurs during molding is corrected, and the roundness and straightness are improved.

As an example, a metal cylindrical tube 200 made of SUS with a length of 1000 mm, an outer diameter of 22 mm, and a thickness of 1 mm may warp by approximately 11.5 mm after forming as shown in FIGS. 6(A) to (C). . In each roller set 10 of the straightening device 100, the uppermost roller set 30 is slightly lowered from the state in which the rollers 32A and 32B of the three sets of roller sets 30 are in contact with the surface of the metal cylindrical tube 200, and the roller set 30 of the three sets of roller sets 30 is slightly lowered to form a roller of about 11.5 mm. When the warped metal cylindrical tube 200 was passed through each roller set 10, the outer diameter was reduced to 21.8 mm, and the warp was reduced to 0.5 mm without any roller marks on the surface.

According to the present invention, it is possible to correct the warp of the metal cylindrical tube 200 with a simple configuration without using a drum-shaped roller shaped according to the diameter of the metal cylindrical tube 200, and to make the metal cylindrical tube 200 perfectly round. The degree and straightness can be factory adjusted.

Note that the above embodiments are merely examples, and the present invention is not limited thereto, and various changes can be made within the scope of the present invention.

For example, the number of roller sets provided in each roller set may be three or more; for example, as shown in FIG. It is also possible to have In this case, the same number of support rollers 40 as the set of rollers 30 can be arranged so that each set is at the same angular position as the pinion gear 33 of the set of rollers 30.

Further, the number of roller sets 10 included in the straightening device 100 is not limited to five, and can be increased or decreased as appropriate depending on the material, diameter, thickness, etc. of the metal cylindrical tube 200 to be straightened.

Furthermore, in the roller assembly 30, the pinion gear 33 does not necessarily have to be placed between the rollers 32A, 32B, but can also be placed outside either one of the rollers 32A, 32B.

10 - Roller set 20 - Geared motor 21 - Drive shaft 30 - Roller set 31 - Rotating shaft 32A, 32B - Roller 40 - Support roller 50 - Ring gear 60 - Drive gear 100 - Straightening device D1 - Feed axis direction 200 - Metal cylindrical tube

Claims (6)

A set of rollers in which two rollers are arranged at intervals around a rotating shaft inclined with respect to the direction of the feed axis of the metal cylindrical tube are arranged at equal intervals in the circumferential direction of the metal cylindrical tube and at the same location in the direction of the feed axis. 3 or more sets of rollers arranged in one stage are arranged in multiple stages along the feed axis direction,
A direction in which the peripheral surfaces of the two rollers are in pressure contact with the surface of the metal cylindrical tube, and the portions of the peripheral surfaces of the two rollers that contact the surface of the metal cylindrical tube are directed forward in the feed axis direction. A method for straightening a metal cylindrical tube, which rotates the two rollers. A set of rollers in which two rollers are arranged at intervals around a rotating shaft inclined with respect to the direction of the feed axis of the metal cylindrical tube are arranged at equal intervals in the circumferential direction of the metal cylindrical tube and at the same location in the direction of the feed axis. a plurality of roller sets arranged in multiple stages along the feed axis direction, with three or more sets arranged in one stage;
a drive mechanism in which a portion of the circumferential surface of the two rollers that is in pressure contact with the surface of the metal cylindrical tube supplies the two rollers with rotation in a forward direction in the feed axis direction;
Straightening device for metal cylindrical tubes. The set of rollers includes a rotating shaft that is inclined with respect to the feed axis direction, and the two rollers are fixed on the same axis with a space between them,
The drive mechanism includes a pinion gear coaxially fixed to the rotating shaft, a ring gear whose internal teeth mesh with the pinion gear, and a drive gear whose internal teeth mesh with the external teeth of the ring gear, to the roller set. 3. The metal cylindrical tube straightening apparatus according to claim 2, further comprising a drive source in which the drive gear is fixed to a drive shaft. The roller set includes a frame that pivotally supports the rotation shaft of at least one set of the roller sets so as to be movable toward and away from the rotation shafts of the other two sets of the roller sets, and also supports the ring gear. Item 3. The metal cylindrical tube straightening device according to item 3. 5. The metal cylindrical tube straightening device according to claim 4, wherein the frame pivotally supports a support roller whose circumferential surface abuts the ring gear in the radial direction at a position in the same phase as the meshing position of the pinion gear. 6. The metal cylindrical tube straightening device according to claim 3, wherein the pinion gear has a smaller diameter than the two rollers and is arranged between the two rollers.

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