JP6281429B2 - Caliber Roll - Google Patents

Description

  The present invention relates to a caliber roll, and more particularly to a caliber roll used when manufacturing a stepped steel pipe.

  A stepped steel pipe is known as a kind of steel pipe. The stepped steel pipe includes, for example, a plurality of grooves. Each of the plurality of grooves is formed on the surface of the steel pipe and extends in the circumferential direction of the steel pipe. The plurality of grooves are arranged at predetermined intervals in the axial direction of the steel pipe. The stepped steel pipe is used as a civil engineering member such as a steel pipe pile.

  A stepped steel pipe is manufactured by processing a steel pipe. For processing the steel pipe, for example, a plurality of caliber rolls are used. The caliber roll is disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-200766.

  In the above publication, the caliber roll includes a roll body. The roll body includes a forming groove. The forming groove is formed on the outer peripheral surface of the roll body. The forming groove contacts the surface of the steel pipe when manufacturing the stepped steel pipe. The caliber roll further includes a convex portion. The convex portion is formed in the molding groove and protrudes from the inner surface of the molding groove. The convex portion includes a rod-shaped member and a built-up portion. The rod-shaped member is embedded in the roll body. A part of the rod-shaped member protrudes from the inner surface of the forming groove. A build-up part covers the part which protrudes from the inner surface of a shaping | molding groove | channel among bar-shaped members.

  When manufacturing a stepped steel pipe, each of a plurality of caliber rolls is rotatably arranged. The plurality of caliber rolls form a forming hole through which the steel pipe passes. The forming hole is formed by a forming groove of each caliber roll. When the steel pipe passes through the forming hole, the convex portion is pressed against the surface of the steel pipe at a predetermined cycle. Thereby, a plurality of grooves arranged at predetermined intervals in the axial direction of the steel pipe are formed on the surface of the steel pipe. As a result, a stepped steel pipe is manufactured.

JP 2012-200766 A

  As described above, when the groove is formed on the surface of the steel pipe, the convex portion is pressed against the surface of the steel pipe. Therefore, a large load is applied to the convex portion. As a result, there is a risk of deformation or damage to the convex portion.

  An object of the present invention is to make it difficult for deformation and breakage to occur in a convex portion in a caliber roll used when manufacturing a stepped steel pipe.

  A caliber roll according to an embodiment of the present invention includes a roll body and an attachment. The attachment is detachably disposed on the roll body. The roll body includes an annular groove and a recess. The annular groove is formed on the outer peripheral surface of the roll body and extends over the entire circumference in the circumferential direction around the central axis of the roll body. A recessed part is formed in the outer peripheral surface of a roll main body, divides | segments an annular groove in the circumferential direction, and an attachment is arrange | positioned. The attachment includes an attachment body and a convex portion. The attachment body has a connection groove connected to the annular groove when the attachment is disposed in the recess. The convex portion is formed integrally with the attachment main body and protrudes from the inner surface of the connection groove.

  The caliber roll according to the embodiment of the present invention is unlikely to be deformed or damaged in the convex portion.

It is a schematic diagram which shows the roll arrange | positioned on the manufacturing line of a stepped steel pipe. It is a side view of the roll shown in FIG. It is a top view of the caliber roll which comprises the roll shown in FIG. It is IV-IV sectional drawing in FIG. It is VV sectional drawing in FIG. It is a top view of the roll main body which comprises the caliber roll shown in FIG. It is VII-VII sectional drawing in FIG. It is VIII-VIII sectional drawing in FIG. It is a side view of the attachment which comprises the caliber roll shown in FIG. It is XX sectional drawing in FIG. FIG. 10 is a plan view of the attachment shown in FIG. 9. It is a bottom view of the attachment shown in FIG. It is explanatory drawing for demonstrating the relationship between the height of a convex part, and the width | variety of an attachment. It is sectional drawing which shows the example of application of the shape of a convex part. It is sectional drawing which shows the application example of attachment to the roll main body of an attachment. It is a side view which shows the application example of a caliber roll. It is a side view which shows the other application example of a caliber roll.

  A caliber roll according to an embodiment of the present invention includes a roll body and an attachment. The attachment is detachably disposed on the roll body. The roll body includes an annular groove and a recess. The annular groove is formed on the outer peripheral surface of the roll body and extends over the entire circumference in the circumferential direction around the central axis of the roll body. A recessed part is formed in the outer peripheral surface of a roll main body, divides | segments an annular groove in the circumferential direction, and an attachment is arrange | positioned. The attachment includes an attachment body and a convex portion. The attachment body has a connection groove connected to the annular groove when the attachment is disposed in the recess. The convex portion is formed integrally with the attachment main body and protrudes from the inner surface of the connection groove.

  In the caliber roll, the convex portion is formed integrally with the attachment main body. Therefore, for example, the strength of the convex portion can be ensured as compared with the case where the convex portion is formed by overlaying, that is, compared with the case where the convex portion is formed separately from the attachment body. As a result, it is difficult for deformation and damage to the convex portion.

  In the caliber roll, the attachment is detachably disposed on the roll body. By replacing the attachment, the shape of the convex portion, that is, the shape of the concave portion to be formed in the stepped steel pipe can be changed. Further, when the convex portion is damaged or deformed, it is not necessary to replace the caliber roll, and the attachment may be replaced.

  Preferably, the caliber roll includes a plurality of attachments. The plurality of attachments are arranged at equal intervals in the circumferential direction.

  In this case, it is possible to suppress the weight of the caliber roll from being biased in the circumferential direction.

  Preferably, the recess includes a first recess and a second recess. The second recess is formed in the first recess. The attachment body includes a protrusion. The protrusion is fitted into the second recess when the attachment is disposed in the recess.

  In this case, the attachment can be positioned.

  Preferably, the caliber roll further includes a weight. The weight is disposed at a position opposite to the position where the attachment is disposed across the central axis of the roll body.

  In this case, the weight of the caliber roll can be prevented from being biased in the circumferential direction by appropriately adjusting the weight of the weight.

  Preferably, the caliber roll further includes a pair of end faces. The pair of end faces are located apart in the axial direction in which the central axis of the roll body extends. Each of the pair of end faces includes a recess. The recess is formed at the same position as the attachment in the circumferential direction.

  In this case, it is possible to prevent the weight of the caliber roll from being biased in the circumferential direction by appropriately setting the size of the recess. The recess may be formed in the roll body or may be formed in the attachment.

  Preferably, the roll body further includes a pair of cylindrical outer peripheral surfaces. The pair of cylindrical outer peripheral surfaces are positioned on both sides of the annular groove in the axial direction in which the central axis of the roll body extends. That is, an annular groove is located between a pair of cylindrical outer peripheral surfaces when viewed from a direction perpendicular to the axial direction of the roll body. The recess divides the annular groove and each of the pair of cylindrical outer peripheral surfaces in the circumferential direction. The recess includes a screw hole. A screw hole is formed in the position which divides each of a pair of cylindrical outer peripheral surfaces in the circumferential direction, and is extended in the radial direction perpendicular | vertical to the axial direction of a roll main body. The attachment further includes a pair of attachment portions. The pair of attachment portions are located on both sides of the connection groove in the axial direction of the roll body when the attachment is disposed in the recess. That is, when the attachment is disposed in the concave portion, the connection groove is located between the pair of attachment portions when viewed from the radial direction of the roll body. Each of the pair of attachment portions includes a through hole. The through hole extends in the radial direction of the roll body when the attachment is disposed in the recess. The caliber roll further includes a bolt. The bolt is inserted into the through hole and screwed into the screw hole.

  In this case, the bolt is located at a position different from the convex portion as viewed from the radial direction. Therefore, the force when the convex portion is pressed against the steel pipe hardly acts on the bolt. As a result, the attachment of the attachment to the roll body is stabilized.

  Preferably, the recess includes a first recess and a second recess. The second recess is formed in the first recess. The body includes a protrusion. The protrusion is accommodated in the second recess when the attachment is disposed in the recess. The protrusion includes a screw hole. When the attachment is disposed in the recess, the screw hole opens in the axial end surface from which the central axis of the roll body extends and extends in the axial direction. The roll body includes a through hole. The through hole opens in the axial end surface of the roll body and the inner surface of the second recess, and is connected to the screw hole when the attachment is disposed in the recess. The caliber roll further includes a bolt. The bolt is inserted into the through hole and screwed into the screw hole.

  In this case, it is not necessary to provide the attachment body with a pair of attachment portions located on both sides of the connection groove in the axial direction of the roll body. As a result, the length of the roll body in the axial direction, that is, the length of the caliber roll in the axial direction can be shortened.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof will not be repeated.

  1 and 2 show a roll 12 arranged on the production line of the stepped steel pipe 10. The roll 12 is the last roll among a plurality of rolls arranged on the production line.

  As shown in FIG. 1, the stepped steel pipe 10 includes a plurality of recesses 10A. The plurality of recesses 10 </ b> A are formed on the outer peripheral surface of the stepped steel pipe 10. The plurality of recesses 10 </ b> A are arranged at predetermined intervals in the axial direction of the stepped steel pipe 10. Each recess 10 </ b> A is, for example, a groove formed over the entire circumference in the circumferential direction of the stepped steel pipe 10. Each recess 10A may not be a groove.

  A plurality of recesses 10 </ b> A are formed by processing the steel pipe 14 moving on the production line by the roll 12. The manufacturing method of the steel pipe 14 is not specifically limited. The steel pipe 14 may be, for example, a welded steel pipe, an electric-resistance-welded steel pipe, a forged steel pipe, or a seamless steel pipe. The steel pipe 14 is processed by the roll 12 in a hot or warm state.

  As shown in FIG. 2, the roll 12 includes two caliber rolls 12A. The two caliber rolls 12A have the same size and the same shape. The two caliber rolls 12A are arranged one above the other. Each caliber roll 12A is rotatably arranged around the central axis L1. Note that the roll 12 may include three or more caliber rolls.

  Each caliber roll 12 </ b> A includes a groove 16 and two convex portions 18. The groove 16 is formed over the entire circumference in the circumferential direction around the central axis L1 of the caliber roll 12A. Each protrusion 18 protrudes from the inner surface of the groove 16. The two convex portions 18 are formed at equal intervals in the circumferential direction of the caliber roll 12A. That is, one convex part 18 is located on the opposite side to the other convex part 18 across the central axis L1. In addition, the number of the convex parts 18 may be one, and may be three or more.

  A forming hole 48 is formed by the two caliber rolls 12A. The forming hole 48 is realized by the groove 16 of each caliber roll 12A. When the steel pipe 14 passes through the forming hole 48, the convex portion 18 is pressed against the surface of the steel pipe 14 at a predetermined cycle. As a result, a stepped steel pipe 10 having a plurality of recesses 10A is manufactured.

[Caliber Roll]
The caliber roll 12A will be described with reference to FIG. 3, FIG. 4, and FIG. The caliber roll 12 </ b> A includes a roll body 20, two attachments 22, and four bolts 24. Each attachment 22 is attached to the roll body 20 by two bolts 24. That is, each attachment 22 is detachably arranged with respect to the roll body 20.

[Roll body]
The roll body 20 will be described with reference to FIGS.

  The roll body 20 is made of steel, for example. The roll body 20 has a cylindrical shape as a whole. That is, the roll body 20 has a hole 20A.

  The hole 20 </ b> A extends in the direction in which the central axis L <b> 1 of the roll body 20 extends, that is, in the axial direction of the roll body 20. The hole 20A is formed so as to penetrate the roll body 20 in the axial direction. That is, the hole 20 </ b> A is open on the end surface 20 </ b> B in the axial direction of the roll body 20.

  The roll body 20 includes a groove 26 and two recesses 28.

  The groove 26 is formed on the outer peripheral surface of the roll body 20. The groove 26 is formed over the entire circumference in the circumferential direction around the central axis L <b> 1 of the roll body 20. That is, the groove 26 is an annular groove.

  The groove 26 opens on the outer peripheral surface of the roll body 20. Here, when viewed from a direction (radial direction) perpendicular to the axial direction of the roll main body 20, the groove 26 is located at the approximate center of the roll main body 20 in the axial direction. That is, the groove 26 divides the outer peripheral surface of the roll body 20 in the axial direction. Thereby, cylindrical outer peripheral surfaces 30 are formed on both sides of the groove 26 in the axial direction of the roll body 20. That is, the groove 26 is located between the pair of outer peripheral surfaces 30 and 30 when viewed from the radial direction of the roll body 20.

  The transverse shape of the groove 26 is substantially constant over the entire circumference of the roll body 20 in the circumferential direction. Incidentally, in this embodiment, the transverse shape of the groove 26 is a substantially semicircular shape.

  The two recesses 28 are formed on the outer peripheral surface of the roll body 20. That is, the recess 28 is open to the outer peripheral surface of the roll body 20.

  The recess 28 is formed over the entire axial direction of the roll body 20 when viewed from the radial direction of the roll body 20. That is, the recess 28 divides the outer peripheral surface of the roll body 20, specifically, the outer peripheral surface 30 in the circumferential direction.

  The recess 28 intersects the groove 26 when viewed from the radial direction of the roll body 20. That is, the recess 28 divides the groove 26 in the circumferential direction of the roll body 20.

  The two recesses 28 are formed at positions facing each other across the central axis L <b> 1 in the circumferential direction of the roll body 20. That is, the two recesses 28 are located at equal intervals in the circumferential direction of the roll body 20.

  Each recess 28 includes a recess 28A and a recess 28B.

  The recess 28 </ b> A is formed over the entire axial direction of the roll body 20. That is, the recess 28 </ b> A divides the outer peripheral surface of the roll body 20, specifically, the outer peripheral surface 30 in the circumferential direction.

  The recess 28A is a groove extending in the axial direction of the roll body 20 with a substantially constant transverse shape. Incidentally, in this embodiment, the transverse shape of the recess 28A is a substantially rectangular shape.

  The recess 28A includes a pair of side surfaces 32 and 32. Each of the pair of side surfaces 32, 32 extends in the axial direction of the roll body 20. The pair of side surfaces 32, 32 face each other in the radial direction perpendicular to the radial direction when viewed from the radial direction of the roll body 20. That is, the pair of side surfaces 32, 32 are separated from each other in the radial direction (second radial direction) perpendicular to the radial direction when viewed from the radial direction (first radial direction) of the roll body 20. The distance between the pair of side surfaces 32, 32 is substantially constant over the entire axial direction of the roll body 20.

  The recess 28A further includes a bottom surface 33. The bottom surface 33 extends in the axial direction of the roll body 20. The bottom surface 33 connects the pair of side surfaces 32 and 32. That is, the width of the bottom surface 33 is substantially constant over the entire axial direction of the roll body 20.

  The recess 28 </ b> A includes two screw holes 44. The screw hole 44 is formed in the bottom surface 33. That is, the screw hole 44 opens in the bottom surface 33. The screw hole 44 is formed in a portion that divides the outer peripheral surface 30 in the recess 28A.

  The recess 28 </ b> B is formed on the bottom surface 33. That is, the recess 28 </ b> B is open to the bottom surface 33.

  The width of the recess 28B (the length in the radial direction of the roll body 20) is the same as the width of the recess 28A (the length in the radial direction of the roll body 20). That is, the recess 28 </ b> B divides the bottom surface 33 in the axial direction of the roll body 20.

  When viewed from the radial direction of the roll main body 20, the recess 28 </ b> B is located at the approximate center in the axial direction of the roll main body 20. When viewed from the radial direction of the roll body 20, the recess 28 </ b> B is located between the two screw holes 44. That is, in the axial direction of the roll main body 20, the screw holes 44 are located on both sides of the recess 28B.

  The recess 28B includes a pair of side surfaces 34,34. Each of the pair of side surfaces 34, 34 extends in the axial direction of the roll body 20. The pair of side surfaces 34 are opposed to each other in the second radial direction when viewed from the first radial direction. That is, the pair of side surfaces 34, 34 are separated in the second radial direction. The distance between the pair of side surfaces 34 is substantially constant over the entire axial direction of the roll body 20.

  The recess 28B further includes a pair of side surfaces 36,36. Each of the pair of side surfaces 36, 36 extends in the second radial direction when viewed from the first radial direction. The pair of side surfaces 36, 36 oppose each other in the axial direction of the roll body 20. That is, the pair of side surfaces 36 and 36 are separated in the axial direction of the roll body 20. The distance between the pair of side surfaces 36, 36 is substantially constant over the entire second radial direction when viewed from the first radial direction.

[attachment]
The attachment 22 will be described with reference to FIGS.

  The attachment 22 is made of steel, for example. Incidentally, in this embodiment, the attachment 22 consists of the same material as the roll main body 20.

  The attachment 22 is disposed in the recess 28. The attachment 22 includes a main body 38, a convex portion 18, and a protrusion 40.

  The main body 38 includes a pair of side surfaces 38A and 38A. Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. At this time, each of the pair of side surfaces 38 </ b> A and 38 </ b> A extends in the axial direction of the roll body 20. The pair of side surfaces 38A and 38A are separated from each other in the second radial direction when viewed from the first radial direction. The distance between the pair of side surfaces 38 </ b> A and 38 </ b> A is substantially constant over the entire axial direction of the roll body 22.

  The main body 38 further includes a pair of side surfaces 38B, 38B. Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. At this time, each of the pair of side surfaces 38B and 38B extends in the second radial direction when viewed from the first radial direction. The pair of side surfaces 38 </ b> B and 38 </ b> B are separated in the axial direction of the roll body 20. The distance between the pair of side surfaces 38B, 38B is substantially constant over the entire second radial direction.

  The main body 38 further includes an end face 38C. Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. At this time, the end surface 38C is curved in an arc shape when viewed from the axial direction of the roll body 20 (see FIGS. 4 and 10).

  The main body 38 further includes an end surface 38D. Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. At this time, the end surface 38D is positioned closer to the central axis L1 than the end surface 38C when viewed from the axial direction of the roll body 20 (see FIG. 5).

  The body 38 further includes a groove 42. The groove 42 opens to the pair of side surfaces 38A, 38A and the end surface 38C.

  Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. When viewed from the radial direction of the roll body 20, the groove 42 is positioned at the approximate center in the axial direction of the roll body 20. The groove 42 extends in the circumferential direction of the roll body 20. The groove 42 divides the end face 38 </ b> C in the axial direction of the roll body 20.

  The transverse shape of the groove 42 is substantially constant over the entire direction in which the groove 42 extends. Incidentally, in this embodiment, the transverse shape of the groove 42 is a substantially semicircular shape.

  The main body 38 further includes a pair of attachment portions 46 and 46. Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. When viewed from the radial direction of the roll body 20, the groove 42 is located between the pair of attachment portions 46, 46.

  Each of the pair of attachment portions 46, 46 includes a hole 46A. The hole 46A opens to the end face 38C and the end face 38D.

  The convex portion 18 is formed integrally with the main body 38. The protrusion 18 protrudes from the inner surface of the groove 42. For example, the protrusion 18 can be formed integrally with the main body 38 by forming the attachment 22 by forging or cutting.

  Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. The protrusion 18 extends in the axial direction of the roll body 20 when viewed from the radial direction of the roll body 20.

  The convex portion 18 is formed in the groove 42 over the entire direction in the direction perpendicular to the direction in which the groove 42 extends, that is, the width direction of the groove 42. In other words, the protrusion 18 divides the groove 42 in the direction in which the groove 42 extends. The convex portion 18 is located in the groove 42 at the approximate center in the direction in which the groove 42 extends.

  The height of the convex portion 18 from the inner surface of the groove 42 is substantially constant at the central portion in the direction in which the convex portion 18 extends (the width direction of the groove 42). The height of the protrusion 18 from the inner surface of the groove 42 gradually decreases from the center to the end in the direction in which the protrusion 18 extends (width direction of the groove 42) at the end in the direction in which the protrusion 18 extends. ing. The convex portion 18 includes an end surface 18A. The end face 18A is formed at the end in the direction in which the convex portion 18 extends. When the convex portion 18 includes the end face 18A, the biting of the steel pipe 14 (see FIG. 1) can be suppressed.

The relationship between the height of the convex portion 18 (height from the inner surface of the groove 42) and the width of the attachment 22 will be described with reference to FIG. First, it is assumed that the attachment 22 is disposed in the recess 28. The roll body 22 is viewed from the axial direction of the roll body 22. At this time, the height from the inner surface of the groove 42 of the convex portion 18 is defined as h. Let w be the width of the protruding end of the convex portion 18. Let L be the width of the attachment 22. The width L of the attachment 22 satisfies the following formula (1).
L <2R · sin (θ1 + θ2) (1)
Here, θ1 satisfies the following equation (2), and θ2 satisfies the following equation (3).
θ1 = arctan ((w / 2) / (R + h)) (2)
θ2 = arccos (R / ((R + h) ² + (w / 2) ² ) ^1/2 ) (3)

  The shape of the protrusion 18, specifically, for example, the height of the protrusion 18 (height from the inner surface of the groove 42), the width of the protrusion 18 (length in the direction in which the groove 42 extends), and the protrusion The cross-sectional shape of the portion 18 (the cross-sectional shape in the direction in which the groove 42 extends) is appropriately set according to the shape of the recess 10A.

For example, as shown in FIG. 14, the convex portion 18 may extend in a direction intersecting the width direction of the groove 42 in the groove 42. In this case, when the width of the groove 42 is WR and the inclination angle of the reference line L3 extending in the longitudinal direction of the protrusion 18 (the direction in which the protrusion 18 extends) with respect to the reference line L2 extending in the width direction of the groove 42 is α. The width L of the attachment 22 satisfies the following formula (4).
L-WR · tan (α) <2R · sin (θ1 + θ2) (4)
Here, θ1 satisfies the above equation (2), and θ2 satisfies the above equation (3).

  The protrusion 40 protrudes from the end surface 38D. The protrusion 40 is formed integrally with the main body 38.

  The protrusion 40 includes a pair of side surfaces 40A and 40A. Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. At this time, each of the pair of side surfaces 40 </ b> A and 40 </ b> A extends in the axial direction of the roll body 20. The pair of side surfaces 40A and 40A are separated from each other in the second radial direction when viewed from the first radial direction. The distance between the pair of side surfaces 40 </ b> A and 40 </ b> A is substantially constant over the entire axial direction of the roll body 22.

  The protrusion 40 further includes a pair of side surfaces 40B and 40B. Here, the state (refer FIGS. 3-5) where the attachment 22 was attached to the roll main body 20 is assumed. At this time, the pair of side surfaces 40B and 40B extend in the second radial direction perpendicular to the first radial direction when viewed from the first radial direction. The pair of side surfaces 40 </ b> B and 40 </ b> B are separated in the axial direction of the roll body 20. The distance between the pair of side surfaces 40B and 40B is substantially constant over the entire second radial direction.

[Attachment of attachment to roll body]
The attachment 22 is attached to the roll body 20 by a plurality of bolts 24. Specifically, it is as follows.

  First, the attachment 22 is disposed in the recess 28 of the roll body 20.

  When the attachment 22 is disposed in the recess 28, the attachment portion 46 is located in the recess 28A (see FIGS. 3 and 5). At this time, only a slight gap is formed between the side surface 38 </ b> A and the side surface 32.

  When the attachment 22 is disposed in the recess 28, the protrusion 40 is positioned in the recess 28B (see FIGS. 4 and 5). At this time, only a slight gap is formed between the side surface 40A and the side surface 34 and between the side surface 40B and the side surface 36. Therefore, when the attachment 22 is disposed in the recess 28, the protrusion 40 is fitted in the recess 28B. As a result, the attachment 22 is positioned in the circumferential direction and the axial direction of the roll body 20.

  In addition, when the attachment 22 is arrange | positioned in the recessed part 28, the processus | protrusion 40 may be contacting the bottom face of the recessed part 28B, and does not need to contact.

  When the attachment 22 is disposed in the recess 28, the side surface 38B is substantially continuous with the end surface 20B (see FIGS. 3 and 5). That is, the side surface 38 </ b> B is substantially at the same position as the end surface 20 </ b> B in the axial direction of the roll body 20.

  When the attachment 22 is disposed in the recess 28, the end surface 38D overlaps the bottom surface 33 (see FIG. 5). At this time, the end surface 38C is substantially continuous with the outer peripheral surface (specifically, the outer peripheral surface 30) of the roll body 20 (see FIG. 4). That is, the distance from the central axis L1 of the end face 38C is substantially the same as the distance from the central axis L1 of the outer peripheral surface (specifically, the outer peripheral surface 30) of the roll body 20.

  When the attachment 22 is disposed in the recess 28, the groove 42 is substantially continuous with the groove 26 in the circumferential direction of the roll body 20 (see FIGS. 3 and 4). That is, the distance from the central axis L1 of the groove 42 is substantially the same as the distance from the central axis L1 of the groove 26. The groove 16 is formed by the groove 42 and the groove 26.

  When the attachment 22 is disposed in the recess 28, the hole 46A and the screw hole 44 are continuous in the radial direction of the roll body 20 (see FIG. 5). The bolt 24 is inserted into the hole 46A. The bolt 24 is screwed into the screw hole 44. Thereby, the attachment 22 is attached to the roll main body 20.

  When manufacturing the stepped steel pipe 10, as shown in FIG.1 and FIG.2, the two caliber rolls 12A are arrange | positioned. At this time, each caliber roll 12A is rotatable about the central axis L1.

  As shown in FIG. 2, the forming hole 48 is formed by the two caliber rolls 12A. The forming hole 48 is realized by the groove 16 (specifically, the groove 26 and the groove 42) of each caliber roll 12A.

  When the steel pipe 14 passes through the forming hole 48, the convex portion 18 is pressed against the surface of the steel pipe 14 at a predetermined cycle. As a result, a stepped steel pipe 10 having a plurality of recesses 10A is manufactured.

  That is, the concave portion 10 </ b> A is formed by pressing the convex portion 18 against the steel pipe 14. Therefore, a large load is applied to the convex portion 18 when the concave portion 10A is formed.

  Here, in the caliber roll 12 </ b> A, the convex portion 18 is formed integrally with the main body 38. Therefore, compared with the case where the convex part 18 is formed separately from the main body 38, the intensity | strength of the convex part 18 is securable. As a result, deformation and breakage of the convex portion 18 are difficult to occur.

  In the caliber roll 12 </ b> A, the attachment 22 is detachably attached to the roll body 20. By replacing the attachment 22, the shape of the convex portion 18, that is, the shape of the concave portion 10A to be formed in the stepped steel pipe 10 can be changed. Further, when the protrusion 18 is damaged or deformed, it is not necessary to replace the caliber roll 12A, and the attachment 22 may be replaced.

  In the caliber roll 12A, the two attachments 22 are arranged at positions facing each other across the central axis L1. Therefore, it is possible to prevent the weight of the caliber roll 12A from being biased in the circumferential direction.

  In the caliber roll 12 </ b> A, each attachment 22 is attached to the roll body 20 by two bolts 24. The convex part 18 is located between the two bolts 24 when viewed from the radial direction. Therefore, the load when pressing the convex portion 18 against the surface of the steel pipe 14 is unlikely to act on the bolt 24. As a result, the attachment of the attachment 22 to the roll body 20 with the bolts 24 is stabilized.

  In the caliber roll 12A, the height of the convex portion 18 and the width of the attachment 22 satisfy the relationship represented by the above-described formula (1). Therefore, when the steel pipe 14 passes through the forming hole 48, the boundary between the attachment 22 and the roll body 20 in the circumferential direction, that is, the gap formed between the side face 34 and the side face 40A, and the steel pipe 14 come into contact with each other. It becomes difficult to do.

[Application example of attachment to the roll body]
In the above embodiment, as shown in FIG. 5, the hole 46A and the screw hole 44 are continuous in the radial direction. For example, as shown in FIG. 15, the hole 50 and the screw hole 52 are in the axial direction. It may be continuous. Hereinafter, the caliber roll 12B will be described with reference to FIG.

  The caliber roll 12B includes a hole 50 and a screw hole 52 instead of the hole 46A and the screw hole 44 as compared with the caliber roll 12A.

  The hole 50 is formed in the roll body 20. The hole 50 extends in the axial direction of the roll body 20. The hole 50 opens to the end surface 20B of the roll body 20 and the side surface 36 of the recess 28B.

  The screw hole 52 is formed in the protrusion 40. Here, it is assumed that the attachment 22 is attached to the roll 20. The screw hole 52 extends in the axial direction of the roll body 20. The screw hole 52 opens to the side surface 40B.

  With the attachment 22 disposed in the recess 28, the hole 50 and the screw hole 52 are continuous in the axial direction of the roll body 20. At this time, the bolt 24 is inserted into the hole 50. The bolt 24 is screwed into the screw hole 52. As a result, the attachment 22 is attached to the roll body 20.

  In the example shown in FIG. 15, it is not necessary to form the pair of outer peripheral surfaces 30, 30 in the roll body 20. As a result, when manufacturing stepped steel pipes of the same size, that is, stepped steel pipes having the same length in the radial direction, the axial length of the roll body 20, that is, the axial length of the caliber roll 12B. The length can be shortened.

[Application examples of Caliber Roll]
In the embodiment described above, the caliber roll 12A includes the two attachments 22. However, for example, the number of attachments 22 may be one. The attachment 22 includes a convex portion 18. Therefore, when there is one attachment 22, the weight of the caliber roll is biased in the circumferential direction. Hereinafter, a method for suppressing the weight of the caliber roll from being biased in the circumferential direction will be described with reference to FIGS. 16 and 17.

  FIG. 16 shows a caliber roll 12C. In the caliber roll 12 </ b> C, only one recess 28 is formed in the roll body 20. Instead, the roll body 20 includes two weights 54. The two weights 54 are disposed on the end surface 20 </ b> B of the roll body 20. The two weights 54 are located on the opposite side of the attachment 22 across the central axis L1. The weight 54 is attached to the end surface 20B with a bolt or the like, for example.

  In the example shown in FIG. 16, the weight of the caliber roll 12 </ b> C can be prevented from being biased in the circumferential direction by appropriately setting the weights of the two weights 54.

  FIG. 17 shows a caliber roll 12D. In the caliber roll 12 </ b> D, only one recess 28 is formed in the roll body 20. Instead, the roll body 20 includes two recesses 56. The recess 56 is formed on the end surface 20 </ b> B of the roll body 20. That is, the recess 56 is open to the end face 20B. The two recessed portions 56 are formed at the same position as the recessed portion 28 in the circumferential direction of the roll body 20.

  Note that the recess 56 may be formed in the attachment 22. In this case, the recessed part 56 is formed in the end surface 38B, for example.

  In the example shown in FIG. 17, by appropriately setting the sizes of the two concave portions 56, it is possible to prevent the weight of the caliber roll 12 </ b> D from being biased in the circumferential direction.

  As mentioned above, although embodiment of this invention has been explained in full detail, these are illustrations to the last and this invention is not limited at all by the above-mentioned embodiment.

12A: Caliber roll, 18: convex part, 20: roll body, 22: attachment, 24: bolt, 26: groove (annular groove), 28: concave part, 28A: concave part (first concave part), 28B: concave part (second) Concave portion), 30: outer peripheral surface (cylindrical outer peripheral surface), 38: main body (attachment main body), 40: protrusion, 42: groove (connection groove), 44: screw hole, 46: mounting portion, 46A: hole (mounting hole) ), 54: weight, 56: recess (recess) L1: central axis

Claims (7)

A roll body;
An attachment that is detachably disposed on the roll body,
The roll body is
An annular groove formed on the outer peripheral surface of the roll body and extending over the entire circumference in the circumferential direction around the central axis of the roll body;
Formed on the outer peripheral surface of the roll body, the annular groove is divided in the circumferential direction, and includes a recess in which the attachment is disposed,
The attachment is
An attachment body having a connection groove connected to the annular groove when the attachment is disposed in the recess;
A caliber roll, which is formed integrally with the attachment main body and includes a protrusion protruding from the inner surface of the connection groove. The caliber roll according to claim 1,
A plurality of attachments;
The plurality of attachments are caliber rolls arranged at equal intervals in the circumferential direction. The caliber roll according to claim 1,
The recess is
A first recess;
A second recess formed in the first recess,
The attachment body is
A caliber roll comprising a protrusion fitted into the second recess when the attachment is disposed in the recess. The caliber roll according to claim 1, further comprising:
A caliber roll comprising a weight disposed at a position opposite to the position where the attachment is disposed across the central axis of the roll body. The caliber roll according to claim 1, further comprising:
Including a pair of end faces positioned apart in the axial direction in which the central axis of the roll body extends,
Each of the pair of end faces is
A caliber roll including a recess formed at the same position as the attachment in the circumferential direction. The caliber roll according to claim 1,
The roll body further includes:
A pair of cylindrical outer peripheral surfaces located on both sides of the annular groove in the axial direction in which the central axis of the roll body extends,
The recess is
The annular groove and each of the pair of cylindrical outer peripheral surfaces are divided in the circumferential direction,
The recess is
Each of the pair of cylindrical outer peripheral surfaces is formed at a position to divide in the circumferential direction, and includes a screw hole extending in a radial direction perpendicular to the axial direction of the roll body,
The attachment further includes:
When the attachment is disposed in the recess, the roll body includes a pair of attachment portions located on both sides of the connection groove in the axial direction,
Each of the pair of attachment portions is
When the attachment is disposed in the recess, including a through hole extending in the radial direction of the roll body,
The caliber roll further comprises:
A caliber roll comprising a bolt inserted through the through hole and screwed into the screw hole. The caliber roll according to claim 1,
The recess is
A first recess;
A second recess formed in the first recess,
The attachment body is
Including a protrusion accommodated in the second recess when the attachment is disposed in the recess;
The protrusion is
When the attachment is arranged in the recess, the roll body includes a screw hole that opens in an axial end surface extending the central axis and extends in the axial direction;
The roll body is
An opening in the axial end face of the roll body and the inner surface of the second recess, and including a through hole connected to the screw hole when the attachment is disposed in the recess,
The caliber roll further comprises:
A caliber roll comprising a bolt inserted through the through hole and screwed into the screw hole.

Images