JP2009172661A - Core body for pipe bender - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a core body for a pipe bender capable of suppressing failure in the thickness reduction on the bending outer peripheral side of a pipe. <P>SOLUTION: When the pipe 9 having the inner wall surface 92 forming a pipe hole 90 is bent, the core body 1 for pipe bender is moved along the length direction of the pipe 9 and forms, in the pipe hole 90 of the pipe 9, an inner wall surface 92 by sliding on the inner wall surface 92 of the pipe 9 along with the moving. The core body 1 has a group 4 of tops. The group 4 of tops has a first top 5 capable of contacting to the inner wall surface part 92p on the bending outer periphery Bp side of the inner wall surface 92 of the pipe 9 when bending the pipe 9, and a second top 6 having lower contact degree than the first top 5 with respect to the inner wall surface part 92p of the bending outer periphery Bp of the inner wall surface 92 of the pipe 9 or does not contact thereto. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a core body for a pipe bender.

Conventionally, when bending a pipe having an inner wall surface that forms a pipe hole, a core for a pipe bender inserted into the pipe hole of the pipe is known (Patent Document 1). Since this core shapes the shape of the inner wall surface of the pipe hole when the pipe is bent, the shape defect of the inner wall surface of the bent pipe can be reduced. The core is formed such that a plurality of pieces are connected in series in the length direction of the pipe, and the plurality of pieces can be bent along the bending shape of the pipe. The outer wall surface of each frame has an outer wall surface portion that contacts the inner wall surface portion on the bending outer peripheral side of the inner wall surface of the pipe when the pipe is bent. Further, each frame has a notch so as not to come into contact with the inner wall surface on the bending inner circumferential side of the inner wall surface of the pipe when bending the pipe. In the above-mentioned Patent Document 1, since the notch is formed in the frame, when the pipe is bent, generation of wrinkles or the like on the inner wall surface portion on the bending inner peripheral side of the inner wall surface of the pipe is suppressed. It is described.
Japanese Patent Laid-Open No. 7-290156

  By the way, when bending a pipe, generally, a larger tensile force acts on the bending outer peripheral side of the pipe than on the bending inner peripheral side of the pipe. Furthermore, the inner wall surface portion on the bending outer periphery side of the inner wall surface of the pipe is strongly rubbed and rubbed by the outer wall surface of the frame, so that the thickness of the bending outer periphery of the pipe tends to decrease, which is not preferable for securing the strength. In particular, when the thickness of the peripheral wall of the pipe is extremely thin, there is a risk that a thinning failure may occur on the bent outer peripheral side of the pipe.

  According to the technique of the above-described Patent Document 1, the notch is formed in the frame so as not to contact the inner wall surface portion on the bending inner peripheral side of the inner wall surface of the pipe. According to such a technique of Patent Document 1, it is not possible to suppress the thinning failure on the bending outer periphery side where the tensile force acts on the pipe.

  This invention is made | formed in view of the above-mentioned situation, and makes it a subject to provide the core body for pipe vendors which can suppress the thinning defect in the bending outer periphery side of a pipe.

  The core body for a pipe bender according to the present invention is moved along the length direction of the pipe when the pipe having the inner wall surface forming the pipe hole is bent, and moves with the movement. A pipe bender core body that slides on the inner wall surface of a pipe to shape the inner wall surface, and the core body is arranged on a bending outer peripheral side of the inner wall surface of the pipe when bending the pipe. Whether the first frame that can contact the inner wall surface portion and the inner wall surface portion between the bending outer peripheral sides of the inner wall surface of the pipe when bending the pipe has a lower contact degree than the first frame. Or a non-contact second frame, the first frame and the second frame are connected in series in the length direction of the pipe and can be bent along the bent shape of the pipe. The top formed Characterized in that it comprises a.

  When bending a pipe, a larger tensile force acts on the outer peripheral side of the pipe than on the inner peripheral side of the pipe. Here, the first frame of the frame group contacts the inner wall surface portion on the bending outer peripheral side of the inner wall surface of the pipe during bending of the pipe, and adjusts the shape of the inner wall surface portion on the bending outer peripheral side. On the other hand, when the pipe is bent, the second frame has a lower degree of contact or non-contact than the first frame with respect to the inner wall surface portion of the bending outer periphery of the inner wall surface of the pipe. For this reason, the inner wall surface portion on the bending outer periphery side of the inner wall surface of the pipe is strongly rubbed and rubbed by the outer wall surface of the first frame, but is not rubbed as strongly as the first frame with the outer wall surface of the second frame. Or non-contact.

  For this reason, according to this invention, it is suppressed that the inner wall surface part of the bending outer peripheral side among the inner wall surfaces of a pipe is excessively rubbed and squeezed by the frame group. As a result, an excessive decrease in the thickness of the bent outer periphery of the pipe is suppressed, which is preferable for ensuring the strength of the pipe on the outer peripheral side. In particular, even when the thickness of the peripheral wall of the pipe is extremely thin, the possibility of occurrence of thinning failure on the bent outer peripheral side of the pipe is reduced.

  The core body is inserted into the pipe hole of the pipe when bending the pipe, moved along the length direction of the pipe, and slides on the inner wall surface of the pipe as it moves to shape the inner wall surface. . The core body includes a frame group having a first frame and a second frame. The first frame can contact an inner wall surface portion on the bending outer peripheral side of the inner wall surface of the pipe during bending of the pipe. The second frame has a lower degree of contact or non-contact than the first frame with respect to the inner wall surface portion of the outer periphery of the pipe during bending of the pipe.

  According to the present invention, the following modes are exemplified.

  -The core has a group of frames. The frame group has a first frame and a second frame. Examples of the material of the first frame and the second frame include metals, ceramic sintered bodies, and hard resins. Examples of the metal include iron, steel, alloy steel, copper alloy, aluminum alloy, titanium alloy, zinc alloy, and tin alloy. Examples of the ceramic sintered body include alumina, silicon carbide, silicon nitride, magnesia, and zirconia. As the hard resin, an engineer plastic having high strength and high toughness is exemplified.

  -A mode in which the first frame is arranged on one end side and the other end side of the frame group in the axial length direction of the core body is exemplified. In this case, a mode in which the second frame is arranged between the first frame on one end side of the frame group and the first frame on the other end side is exemplified. In this case, a mode in which one or more first frames are arranged on one end side of the frame group is illustrated. A mode in which one or more first frames are arranged on the other end side of the frame group is illustrated. The second frame is exemplified by a single or a plurality of second frames arranged between the first frames forming both ends of the frame group.

  -The aspect by which the 1st top and the 2nd top are alternately arranged in series in the axial length direction of a core is illustrated. Therefore, the aspect arrange | positioned in order of 1st frame, 2nd frame, 1st frame, 2nd frame ... is illustrated. Moreover, the aspect arrange | positioned in order of 2nd frame, 1st frame, 2nd frame, 1st frame ... is illustrated.

  In the cross section along the axis of the pipe, the dimension of the outer wall surface of the outer wall of the first frame facing the bending outer peripheral side of the outer wall of the first frame with respect to the central axis of the frame group is D1, and the outer wall of the second frame When the dimension of the outer wall surface part facing the bending outer peripheral side of a pipe is set to D2, D2 is set smaller than D1 (D2 <D1). Examples of D2 / D1 include a range of 0.5 to 0.98, a range of 0.6 to 0.95, and a range of 0.7 to 0.9.

  -In the projection projected in parallel to the central axis of the frame group, the outer wall surface part facing the bending outer peripheral side of the pipe among the outer wall surfaces of the second frame is exemplified as an arc convex shape . In this case, when the intersection of the virtual perfect circle that makes a round around the central axis of the frame group and the outer wall surface of the second frame intersects, the intersection is the inner circumferential side of the pipe in the radial direction of the pipe. A mode in which the position is set to any one of the positions of the bent outer periphery of the pipe and the intermediate position between the bent inner periphery and the bent outer periphery of the pipe is exemplified.

  -In the projection projected in parallel with the central axis of the frame group, the outer wall surface part facing the bending outer periphery side of the pipe of the outer wall surface of the second frame has a linear portion extending linearly. The aspect which is shown is illustrated. The straight portion is easily machined. An example in which both the first frame and the second frame are in contact with the inner wall surface on the bending inner peripheral side of the pipe when the pipe is bent is illustrated.

  According to the present invention, if the core body is reciprocated in the pipe of the pipe while the pipe is bent or while bending the pipe, the first frame is bent on the inner wall surface of the pipe. Make strong contact with the inner wall surface on the side. On the other hand, the second frame does not contact the inner wall surface portion on the bending outer peripheral side of the inner wall surface of the pipe as strongly as the first frame, or is not in contact.

  For this reason, it is suppressed that the inner wall surface part on the bending outer peripheral side of the inner wall surface of the pipe is excessively rubbed and rubbed by the frame group. As a result, an excessive decrease in the thickness of the peripheral wall on the bending outer periphery side of the pipe is suppressed. Therefore, it is preferable for securing the strength of the outer periphery of the pipe. In particular, even when the thickness of the peripheral wall of the pipe is extremely thin, the possibility of occurrence of thinning failure on the bent outer peripheral side of the pipe is reduced. It is possible to suppress the thinning failure on the bent outer peripheral side of the pipe.

  Hereinafter, each embodiment of the present invention will be described.

(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIGS. When bending the pipe 9 having the inner wall surface 92 that forms the pipe hole 90, the core body 1 for the pipe bender is reciprocated along the length direction of the pipe 9 in the pipe hole 90 of the pipe 9. As the core body 1 reciprocates, the core body 1 slides on the inner wall surface 92 of the pipe 9 to shape the inner wall surface 92.

  The pipe 9 is formed using a metal as a base material. The metal is not particularly limited, and examples thereof include iron-based, steel-based, aluminum alloy, and titanium alloy. The use of the pipe 9 is not particularly limited, and examples thereof include parts mounted on a vehicle and parts mounted on an industrial machine. Examples include a pipe that forms an exhaust gas passage, a pipe that supplies fuel, a pipe that supplies a gas such as air, and the like. Here, as shown in FIGS. 1A and 1B, the bending outer peripheral side of the pipe 9 is shown as Bp. The bending inner peripheral side of the pipe 9 is shown as Bi.

  As shown in FIG. 1 (A), the core body 1 is connected to the drive source 2 via a long connecting tool 20 having rigidity. The drive source 2 is a hydraulic drive device or a motor drive device, but is not limited thereto.

  The core body 1 includes a base 3 and a frame group 4 connected to the base 3. The frame group 4 includes a first frame 5 and a second frame 6. The first frame 5 and the second frame 6 are connected in series in the length direction of the pipe 9 and are formed to be able to bend along the bending shape of the pipe 9. The first frame 5 is a frame that comes into contact with the inner wall surface portion 92p on the bending outer periphery Bp side of the inner wall surface 92 of the pipe 9 when the pipe 9 is bent. The second frame 6 is a frame whose contact degree is lower or non-contact than the first frame 5 with respect to the inner wall surface portion 92p of the bending outer periphery Bp of the inner wall surface 92 of the pipe 9 when the pipe 9 is bent. is there.

  In other words, when the pipe 9 is bent, the first piece 5 is in strong contact with the inner wall surface portion 92p on the bending outer periphery Bp side of the inner wall surface 92 of the pipe 9. On the other hand, when the pipe 9 is bent, the second top 6 is weakly in contact with or not in contact with the inner wall surface 92p of the bending outer periphery Bp of the inner wall 92 of the pipe 9.

  As shown in FIGS. 1 (A) and 1 (B), the first frame 5 is arranged on one end side and the other end side of the frame group 4 in the axial direction of the core body 1 (corresponding to the length direction of the pipe 9). Each is arranged. In this case, the second frame 6 is arranged between the first frame 5 on one end side of the frame group 4 and the first frame 5 on the other end side.

  Further explanation will be added. 1A and 1B show a cross section along the axis so as to pass through the axis of the pipe 9. As shown in FIG. 1A, with respect to the central axis N1 of the frame group 4, the dimension of the outer wall surface portion 50p facing the bending outer periphery Bp side of the pipe 9 in the outer wall surface 50 of the first frame 5 is D1. When the dimension of the outer wall surface portion 60p facing the bending outer circumference Bp of the pipe 9 in the outer wall surface 60 of the second frame 6 is D2, D2 is set smaller than D1 (D2 <D1).

  Here, it is preferable that D2 / D1 is set within the allowable range of the ovalization rate of the cross section of the bent shape of the pipe. Here, examples of D2 / D1 include a range of 0.5 to 0.98, a range of 0.6 to 0.95, and a range of 0.7 to 0.9. The ovalization rate (%) is represented by [((major axis−minor axis) / major axis) × 100].

  FIG. 4 is a projection view in which the first frame 5 is projected in parallel to the central axis N1 of the frame group 4. As shown in FIG. 4, the outer wall surface 50 of the first frame 5 is formed with a circular (perfect circular) outer contour with respect to the central axis N <b> 1 of the frame group 4. FIG. 5 shows a projection view in which the second frame 6 is projected in parallel to the central axis N1 of the frame group 4. FIG. As shown in FIG. 5, most of the outer wall surface 60 of the second frame 6 is formed with a circular (perfect circular) outer contour with respect to the central axis N <b> 1 of the frame group 4. However, the outer wall surface portion 60p facing the bent outer periphery Bp side of the pipe 9 in the outer wall surface 60 of the second frame 6 is a straight portion 68 that extends in a straight line so as to form a crescent-shaped cutout portion 69. Have The straight portion 68 is easily machined. Thus, since the notch 69 is formed in the second frame 6, the straight portion 68 of the outer wall surface 60 of the second frame 6 is less likely to contact the inner wall surface 92 of the pipe 9.

  As shown in FIGS. 1 to 3, when the pipe 9 is bent, both the first frame 5 and the second frame 6 are the same as the inner wall surface 92 i on the bending inner circumference Bi side of the inner wall 92 of the pipe 9. Contact with moderate contact force. For this reason, shaping in the inner wall surface portion 92i on the bent inner circumference Bi side of the inner wall surface 92 of the pipe 9 can be favorably performed.

  As described above, the first frame 5 and the second frame 6 are formed so as to be connected in series in the length direction of the pipe and bend along the bending shape of the pipe 9. As shown in FIG. 3, a hole 70 having a spherical inner surface 71 is formed in the base 3 on the frame group 4 side. In the first frame 5, a protrusion 75 having a spherical outer surface 76 and a hole 70 having a spherical inner surface 71 are formed on opposite sides. In the second frame 6, a protrusion 75 having a spherical outer surface 76 and a hole 70 having a spherical inner surface 71 are formed on opposite sides. The hole 70 of the base 3 and the protrusion 75 of the first frame 5 are fitted so as to be rotatable in one direction (forward / reverse direction). In the first frame 5 and the second frame 6 provided adjacent to each other, the hole 70 and the protrusion 75 are fitted so as to be rotatable in one direction (forward and reverse directions). Thus, the first frame 5 and the second frame 6 are formed so as to be connected in series in the length direction of the pipe 9 and bend along the bending shape of the pipe 9.

  In addition, when fitting the hole 70 and the protrusion 75, shrink fitting, cold fitting, press fitting, etc. are illustrated. In shrink fitting, the hole 70 and the protrusion 75 are fitted in a state where the diameter of the hole 70 is increased by heating, and then the hole 70 side is cooled to room temperature. In the cold fitting, the hole 70 and the protrusion 75 are fitted in a state where the diameter of the protrusion 75 is cooled and reduced, and then the protrusion 75 side is returned to room temperature. In press fitting, the hole 70 and the protrusion 75 are forcibly fitted. Further, the base 3, the first piece 5 and the second piece 6 having the holes 70 are each formed of a plurality of divided bodies, and the divided bodies are integrally coupled by bolting or the like, and the base 3, the first piece 5 and the first piece Two frames 6 may be formed respectively.

  The material of the first frame 5 and the second frame 6 is not particularly limited. Examples include metals and ceramics sintered bodies. Examples of the metal include iron, steel, alloy steel, copper alloy, aluminum alloy, titanium alloy, zinc alloy, and tin alloy. Examples of the ceramic sintered body include alumina, silicon carbide, silicon nitride, magnesia, and zirconia.

  A description will be given of how to use the core body 1. When the pipe 9 is bent, a tensile force F1 (see FIG. 2 (A)) larger than the bending inner periphery Bi side of the pipe 9 acts on the bending outer periphery Bp side of the pipe 9. For this reason, the thickness of the peripheral wall on the side of the bent outer periphery Bp of the pipe 9 generally tends to be thinner than the thickness of the peripheral wall on the side of the bent inner periphery Bi of the pipe 9.

  First, as shown in FIG. 1A, the core body 1 is connected to the drive source 2 via the connector 20. A clamping operation is performed in which a predetermined portion of the pipe 9 is sandwiched by the first clamp tool 101 and another predetermined portion of the pipe 9 is sandwiched by the second clamp tool 102. In this state, an insertion operation for inserting the core body 1 from the frame group 4 to a predetermined position in the pipe hole 90 of the pipe 9 is performed. Note that the clamping operation may be performed after the insertion operation. The insertion operation and the clamping operation may be performed simultaneously.

  FIG. 1B shows a state in which the core body 1 has reached the planned bending portion 91 of the pipe 9. In this state, as shown in FIG. 2A, the second clamp tool 102 is moved in one direction (arrow A1 direction), and the planned bending portion 91 of the pipe 9 is applied to the outer wall surface 99a of the bending jig 99. Bend. FIG. 2A shows a state where the pipe 9 is bent at the bending angle θ1.

  Thus, when bending the pipe 9, both the first frame 5 and the second frame 6 of the frame group 4 come into contact with the inner wall surface portion 92 i on the bending inner circumference Bi side of the inner wall surface 92 of the pipe 9. The abnormal deformation of the inner wall surface portion 92i is suppressed. Further, as shown in FIG. 2, the first frame 5 of the frame group 4 contacts the inner wall surface portion 92p on the bent outer periphery Bp side of the inner wall surface 92 of the pipe 9, and the inner wall surface portion 92p on the bent outer periphery Bp side Suppresses abnormal deformation.

  On the other hand, as shown in FIG. 2, the second frame 6 is different from the first frame 5 when the pipe 9 is bent with respect to the inner wall surface 92 p of the bending outer periphery Bp of the inner wall 92 of the pipe 9. Therefore, the contact degree is lower than that of the first frame 5 or is not in contact.

  In the state where the pipe 9 is bent as described above, the drive source 2 is driven, and the core body 1 is reciprocated by a predetermined stroke along the length direction of the pipe a plurality of times via the connector 20. For this reason, the inner wall surface portion 92 p on the bent outer periphery Bp side of the inner wall surface 92 of the pipe 9 is strongly rubbed and rubbed by the outer wall surface 50 of the first frame 5. On the other hand, the outer wall surface 60 of the second frame 6 is not rubbed as strongly as the first frame 5 with the inner wall surface portion 92p on the bending outer periphery Bp side, or is not in contact with it.

  For this reason, according to the present embodiment, excessive rubbing of the inner wall surface portion 92p on the bent outer periphery Bp side of the inner wall surface 92 of the pipe 9 with the frame group 4 is suppressed. As a result, the inner wall surface portion 92p is prevented from being excessively squeezed.

  Thereafter, in a state where the pipe 9 is sandwiched between the first clamp tool 101 and the second clamp tool 102, the second clamp tool 102 is moved in one direction (arrow A1) so that the bending angle θ1 (see FIG. 2A) increases. Bend further in the direction). In this state, as described above, the core body 1 is reciprocated a plurality of times with a predetermined stroke along the length direction of the pipe by the driving force of the driving source 2. For this reason, the inner wall surface portion 92p on the bent outer periphery Bp side of the inner wall surface 92 of the pipe 9 is strongly rubbed and rubbed by the outer wall surface 50 of the first frame 5 as described above.

  On the other hand, the outer wall surface 60 of the second frame 6 is not rubbed as strongly with the inner wall surface portion 92p on the bending outer periphery Bp side of the inner wall surface 92 of the pipe 9 as the first frame 5 is. Alternatively, the outer wall surface 60 of the second frame 6 is not in contact with the inner wall surface portion 92p.

  Further, as described above, the pipe 9 is further bent so that the bending angle θ1 increases. In this state, the core 1 in the pipe 9 is reciprocated a predetermined number of times along the length direction of the pipe 9 by the driving force of the driving source 2 as described above. For this reason, the inner wall surface portion 92p on the bent outer periphery Bp side of the inner wall surface 92 of the pipe 9 is strongly rubbed and rubbed by the outer wall surface 50 of the first frame 5 as described above. On the other hand, the outer wall surface 60 of the second frame 6 is not rubbed as strongly as the first frame 5 with the inner wall surface portion 92p on the bent outer periphery Bp side, or is not in contact. The above operation is repeated until the bending angle θ1 reaches a predetermined bending angle.

  According to this embodiment, the inner wall surface 92p on the bending outer periphery Bp side of the inner wall surface 92 of the pipe 9 is suppressed from being rubbed excessively by the frame group 4. Eventually, excessive bending of the inner wall surface portion 92p on the bending outer periphery Bp side is suppressed. As a result, excessive extension in the line length of the bending outer periphery Bp of the pipe 9 is suppressed. Therefore, in the prior art, the line length on the side of the bending outer periphery Bp of the pipe 9 is β1 (not shown). Can be suppressed to β2 (not shown) (β1> β2). Thereby, according to this embodiment, the excessive reduction of the thickness of the surrounding wall by the side of the bending outer periphery Bp of the pipe 9 is suppressed. In particular, even when the thickness of the peripheral wall of the pipe 9 is as extremely thin as 0.5 millimeters or less, the possibility of occurrence of thinning failure on the peripheral wall on the bent outer periphery Bp side of the pipe 9 is reduced.

(Embodiment 2)
FIG. 6 shows a second embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. FIG. 6 shows a projection view in which the second frame 6 is projected in parallel to the central axis N1 of the frame group 4. FIG. As shown in FIG. 6, of the outer wall surface 60 of the second frame 6, the outer wall surface portion 60 p facing the bending outer periphery Bp side of the pipe 9 has an arcuate convex shape.

  In this case, as shown in FIG. 6, when the intersection of the virtual perfect circle 60k that makes a round around the central axis N1 of the frame group 4 and the outer wall surface 60 of the second frame 6 is an intersection 60x, the intersection 60x Is arranged at a position on the bending outer circumference Bp side of the pipe 9 in the radial direction of the pipe 9 (arrow R direction). In this case, as can be understood from FIG. 6, the cutout amount Kc at the center of the second frame 6 can be secured, but the cutout amount Ke at the end of the second frame 6 is reduced. The second frame 6 according to the present embodiment has a lower degree of contact with the inner wall surface 92 of the pipe 9 than in the case of the first embodiment shown in FIG.

(Embodiment 3)
FIG. 7 shows a third embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. FIG. 7 is a projection view in which the second frame 6 is projected in parallel to the central axis N1 of the frame group 4. As shown in FIG. 7, the outer wall surface portion 60 p of the outer wall surface 60 of the second frame 6 facing the bending outer periphery Bp side of the pipe 9 has an arcuate convex shape.

  In this case, when the intersection of the virtual perfect circle 60k that goes around the central axis N1 of the frame group 4 and the outer wall surface 60 is an intersection 60x, the intersection 60x is the radial direction of the pipe 9 (arrow R direction). The pipe 9 is set at a position on the bending inner circumference Bi side. In this case, as shown in FIG. 7, the notch amount Kc at the center of the second frame 6 can be secured, and the notch amount Ke at the end of the second frame 6 can also be secured. For this reason, the outer wall surface 60 of the second frame 6 can slide on the inner wall surface portion 92i on the bent inner circumference Bi side of the inner wall surface 92 of the pipe 9, but the outer wall surface 60 of the second frame 6 does not move inside the pipe 9. Of the wall surface 92, the inner wall surface portion 92p on the bent outer periphery Bp side is likely to be non-contact. Note that the second frame 6 according to the present embodiment has a lower degree of contact with the inner wall surface 92 of the pipe 9 than in the second embodiment shown in FIG.

(Embodiment 4)
FIG. 8 shows a fourth embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. FIG. 8 is a projection view in which the second frame 6 is projected in parallel to the central axis N1 of the frame group 4. As shown in FIG. 8, the outer wall surface portion 60 p of the outer wall surface 60 of the second frame 6 facing the bending outer periphery Bp side of the pipe 9 has a circular arc shape. In this case, when the intersection of the virtual perfect circle 60k that goes around the central axis N1 of the frame group 4 and the outer wall surface 60 is an intersection 60x, the intersection 60x is the radial direction of the pipe 9 (arrow R direction). The intermediate position Bi is set at an intermediate position between the bending inner periphery Bi and the bending outer periphery Bp of the pipe 9.

(Embodiment 5)
FIG. 9 shows a fifth embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. In the axial length direction of the core body 1, the first frames 5 and the second frames 6 are alternately arranged in series. Accordingly, the first frame 5, the second frame 6, the first frame 5, the second frame 6, and the first frame 5 are arranged and connected in this order from the base 3 side. Also in this embodiment, excessive reduction in the thickness of the peripheral wall on the bent outer periphery Bp side of the pipe 9 is suppressed.

(Embodiment 6)
FIG. 10 shows a sixth embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 10, the protrusion 75 is fitted to the hole 70 so as to be rotatable in one direction (forward / reverse direction). However, the protrusion 75r is formed with an engagement protrusion 75r. In the hole 70, a space 70r in which the engagement protrusion 75r can move is formed. When the engagement protrusion 75r moves excessively in the circumferential direction (arrow SA direction) of the second frame 6, it engages with the stopper 70s in the space 70r. Thus, the second frame 6 is prevented from excessively rotating around the axis N1 in the circumferential direction (arrow SA direction). Therefore, it is suppressed that the straight part 68 moves from the bending outer periphery Bp side to the bending inner periphery Bi side.

(Embodiment 7)
FIG. 11 shows a seventh embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. The relationship between the hole 70 and the protrusion 75 is reversed with respect to the first embodiment. That is, as shown in FIG. 11, a protrusion 75 having a spherical outer surface 76 is formed on the top group 3 on the frame group 4 side. In the first frame 5, a hole 70 having a spherical inner surface 71 and a protrusion 75 having a spherical outer surface 76 are formed on opposite sides. In the second frame 6, a hole 70 having a spherical inner surface 71 and a protrusion 75 having a spherical outer surface 76 are formed on opposite sides. The hole 70 of the first frame 5 and the protrusion 75 of the base 3 are fitted so as to be rotatable in one direction (forward / reverse direction). In the first frame 5 and the second frame 6 provided adjacent to each other, the hole 70 and the protrusion 75 are fitted so as to be rotatable in one direction (forward and reverse directions). Thus, the first frame 5 and the second frame 6 are formed so as to be connected in series in the length direction of the pipe 9 and bend along the bending shape of the pipe 9.

(Embodiment 8)
FIG. 12 shows an eighth embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 12, the core body 1 includes a base 3 and a frame group 4. The frame group 4 is formed by alternately arranging the first frame 5 and the second frame 6B in series. Accordingly, the first frame 5, the second frame 6B, the second frame 6B, and the first frame 5 are arranged and connected in this order from the base 3 side. The second top 6B is formed by a top body 600 and an appendage 602 joined to the top body via an elastically deformable elastic layer 601. The elastic layer 601 is made of resin or rubber, and may be thermosetting or thermoplastic.

  The first frame 5 contacts the inner wall surface portion 92p on the bending outer periphery Bp side of the inner wall surface 92 of the pipe 9, and adjusts the shape of the inner wall surface portion 92p on the bending outer periphery Bp side. On the other hand, in the 2nd top 6B, a contact degree is lower than the 1st top 5 with respect to the inner wall surface part 92p of bending outer periphery Bp among the inner wall surfaces 92 of the pipe 9. FIG. This is because the elastic layer 601 can be elastically deformed.

(Embodiment 9)
13 and 14 show a ninth embodiment. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As illustrated in FIG. 13, the core body 1 does not include a base portion but includes a frame group 4C. The top group 4 </ b> C is formed so that the first top 5 </ b> C and the second top 6 </ b> C are connected in series in the length direction of the pipe 9 and can be bent along the bending shape of the pipe 9. The first frame 5C includes a first rotation part 531 disposed in the center of the first frame 5C, a first arm part 532 extending radially outward from the first rotation part 531, and a first And a first ring body 533 provided continuously to the arm portion 532. The outer wall surface of the first ring body 533 has a perfect circle shape. The second frame 6C includes a second rotating part 631 disposed at the center of the second frame 6C, a second arm part 632 extending radially outward from the second rotating part 631, and a second And a second ring body 633 that is connected to the arm portion 632.

  A rotation pin 540 is fitted in the through hole 535 of the first rotation part 531 and the through hole 635 of the second rotation part 631. The first rotating portion 531 and the second rotating portion 631 are rotatable with respect to each other about the rotation pin 540 as if it were a chain. As a result, the first frame 5C and the second frame 6C are rotatable with respect to each other. Thus, the first frame 5C and the second frame 6C are rotatable with respect to the rotation pin 540 extending in one direction as a rotation fulcrum. For this reason, relative movement in the circumferential direction (arrow SA direction) of the first ring body 533 and the second ring body 633 is suppressed. Therefore, the first ring body 533 and the second ring body 633 are prevented from rotating from the bending inner periphery Bi to the bending outer periphery Bp in the arrow SA direction.

  As shown in FIG. 14B, the second ring body 633 has a notch 69 having a substantially crescent shape. The notch 69 faces the inner wall surface 92p on the bent outer periphery Bp side of the inner wall 92 of the pipe 9, but weakens the contact force with the inner wall 92b.

  As shown in FIG. 13, when the first rotation unit 531 and the second rotation unit 631 are in a straight line, the central axis N1 of the first rotation unit 531 and the second rotation unit 631 is The dimension of the outer wall surface part 50p facing the bending outer periphery Bp side of the pipe 9 in the outer wall surface 50 of the first frame 5C is defined as D1. Furthermore, let D2 be the dimension of the outer wall surface portion 60p facing the bending outer periphery Bp side of the pipe 9 in the outer wall surface 60 of the second frame 6C. At this time, D2 is set smaller than D1 (D2 <D1). Here, examples of D2 / D1 include a range of 0.5 to 0.98, a range of 0.6 to 0.95, and a range of 0.7 to 0.9. However, it is not limited to this.

  The first frame 5C of the frame group 4 is in contact with the inner wall surface portion 92p on the bent outer periphery Bp side of the pipe 9 and adjusts the shape of the inner wall surface portion 92p, as in the above-described embodiment. In contrast, the second frame 6C has a lower degree of contact with or not in contact with the inner wall surface portion 92p of the bending outer periphery Bp of the pipe 9 than the first frame 5C.

  For this reason, the inner wall surface portion 92p of the pipe 9 on the bent outer periphery Bp side is suppressed from being rubbed excessively by the frame group 4C. As a result, an excessive decrease in the thickness of the peripheral wall of the bending outer periphery Bp of the pipe 9 is suppressed. It is preferable for securing the strength of the bending outer periphery Bp of the pipe 9. In particular, even when the thickness of the peripheral wall of the pipe 9 is extremely thin, the possibility of occurrence of a thinning failure on the bent outer periphery Bp side of the pipe 9 is reduced.

(Application 1)
FIG. 15 shows Application Mode 1. The present embodiment has basically the same configuration and effect as the first embodiment. Hereinafter, the description will focus on the different parts. As shown in FIG. 15, the present invention is applied to an exhaust gas exhaust manifold 700 mounted on a vehicle or the like together with an internal combustion engine. The manifold 700 is formed by inserting the bent pipe 710 into the manifold main body 701 through the opening 702 and assembling it with an assembling means such as welding. The bent pipe 710 includes a metal outer pipe 711 and a metal inner pipe 713 inserted substantially coaxially into the outer pipe 711 so as to form a heat insulating space 712 between the outer pipe 711. ing.

  In order to reduce the heat transfer amount of the exhaust gas passing through the pipe hole 714 of the inner pipe 713, the thickness of the inner pipe 713 is set to be thinner than the thickness of the outer pipe 711, for example, 0.2 to 2 mm, It is set to 0.4-1 mm. For this reason, when the inner pipe 713 is formed by bending, excessive thinning or chipping may occur when the bending degree is high on the outer periphery side of the inner pipe 713 where the tensile stress is applied. Therefore, if the core body 1 according to the above-described embodiment is used, excessive thinning of the inner pipe 713 on the bending outer peripheral side can be suppressed.

(Application 2)
FIG. 16 shows Application Mode 2. A curved pipe 810 (exhaust pipe) is assembled to a three-way catalytic converter 801 (purification device body) to form a catalytic converter device 800 (exhaust gas purification device). The bent pipe 810 has a bent portion 812 whose bending angle is as large as 40 degrees or more, and is connected to the main muffler and the sub muffler.

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

  (Additional Item 1) A pipe bender that bends a pipe having an inner wall surface that forms a pipe hole, the clamp tool holding a predetermined portion of the pipe, and a planned bending portion of the pipe being brought into contact with each other. A bending jig for bending the pipe, and a core body that is moved along the length direction of the pipe and slides on the inner wall surface of the pipe as it moves to shape the inner wall surface. The core includes a first frame that can contact an inner wall surface portion on the bending outer periphery side of the inner wall surface of the pipe when the pipe is bent, and the inner wall surface of the pipe when the pipe is bent. The second frame has a lower contact degree or non-contact than the first frame with respect to the inner wall surface portion on the bending outer peripheral side, and the first frame and the second frame are connected to the length of the pipe. In series in each direction Tube Bender, characterized in that it comprises a pivotally configured frame group. In this case, of the inner wall surface of the pipe, the inner wall surface portion on the bending outer periphery side is suppressed from being rubbed excessively by the frame group. As a result, an excessive decrease in the thickness of the peripheral wall on the bending outer periphery side of the pipe is suppressed. Therefore, it is preferable for securing the strength of the outer periphery of the pipe.

  The present invention can be used when bending a pipe.

(A) is sectional drawing which shows the state which has inserted the core into the pipe hole of a pipe, (B) is sectional drawing which shows the state which inserted the core into the bending plan part of the pipe hole of a pipe. (A) is sectional drawing which shows the state which is bending the pipe in the state which inserted the core to the bending plan part of the pipe hole of a pipe, (B) moves a core within the bent pipe It is sectional drawing which shows the state made to do. It is sectional drawing which shows the state which has moved the core within the pipe which carried out the bending process. It is the projection which projects the 1st frame in parallel with respect to the central axis of a frame group. It is the projection which projects the 2nd top in parallel to the central axis of a top group. FIG. 10 is a projection view according to the second embodiment, in which a second frame is projected in parallel to the central axis of the frame group. FIG. 10 is a projection view according to the third embodiment, in which a second frame is projected in parallel to the central axis of the frame group. FIG. 10 is a projection view according to the fourth embodiment, in which a second frame is projected in parallel to the central axis of the frame group. It is sectional drawing which concerns on Embodiment 5 and shows the state which has moved the core within the pipe which carried out the bending process. FIG. 20 is a configuration diagram illustrating an internal structure of a second frame according to the sixth embodiment. FIG. 10 is a cross-sectional view of a core body according to a seventh embodiment. It is sectional drawing which shows the state which has moved the core within the pipe which carried out the bending process. FIG. 10 is a cross-sectional view of a core body according to an eighth embodiment. (A) is sectional drawing which shows a 1st top, (B) is sectional drawing which shows a 2nd top. It is a perspective view which concerns on the application form 1. FIG. It is a perspective view concerning application form 2.

Explanation of symbols

  1 is a core body, 2 is a driving source, 3 is a base, 4 is a frame group, 5 is a first frame, 50 is an outer wall surface, 6 is a second frame, 60 is an outer wall surface, 60x is an intersection, 69 is a notch, 9 is a pipe, 90 is a pipe hole, 92 is an inner wall surface, Bp is a bending outer periphery, and Bi is a bending inner periphery.

Claims (7)

When bending a pipe having an inner wall surface that forms a pipe hole, the pipe is moved along the longitudinal direction of the pipe along the length direction of the pipe and slides on the inner wall surface of the pipe as it moves. A core for a pipe bender that shapes the wall,
The core is
A first frame that can contact an inner wall surface portion on the outer circumferential side of the inner wall surface of the pipe when bending the pipe, and the outer circumferential side of the inner wall surface of the pipe when bending the pipe. A second frame having a contact degree lower than or not in contact with the inner wall portion of the first frame, and the first frame and the second frame are connected in series in the length direction of the pipe. And a core for a pipe bender, comprising a top group formed so as to be able to bend along the bent shape of the pipe.   2. The first frame according to claim 1, wherein the first frame is disposed on one end side and the other end side of the frame group in the axial length direction of the core body, and the second frame is the first frame on the one end side of the frame group. A core body for a pipe bender, which is disposed between one frame and the first frame on the other end side.   2. The core body for a pipe bender according to claim 1, wherein the first frame and the second frame are alternately arranged in the axial length direction of the core body.   The bending outer peripheral side of the pipe according to any one of claims 1 to 3, wherein the pipe is out of the outer wall surface of the first frame with respect to the central axis of the frame group in a cross section along the axis of the pipe. D2 is set to be smaller than D1, where D1 is the dimension of the outer wall surface facing the pipe and D2 is the dimension of the outer wall surface facing the bending outer periphery of the pipe among the outer wall surfaces of the second frame. (D2 <D1), a core for a pipe bender.   5. The projection view according to claim 1, wherein the projection is projected in parallel with a central axis of the frame group, and faces the bending outer peripheral side of the pipe among the outer wall surfaces of the second frame. The outer wall surface portion has an arcuate convex shape, and when the virtual circle that goes around the central axis of the frame group and the outer wall surface of the second frame intersect with each other, The intersection is in the radial direction of the pipe at any one of the position on the inner side of the bend of the pipe, the position on the outer side of the bend of the pipe, and the intermediate position between the inner periphery of the bend and the outer periphery of the bend. Core body for pipe bender characterized by being set.   5. The projection according to claim 1, wherein the projection is projected in parallel with the central axis of the frame group, and the pipe faces out of the outer peripheral wall surface of the second frame on the bending outer peripheral side. The outer wall surface portion of the pipe bender has a linear portion extending linearly, and the pipe bender core.   7. The method according to claim 1, wherein the first piece and the second piece are in contact with the inner wall surface of the pipe on the inner circumferential side when the pipe is bent. Core for pipe bender.

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