JP5288749B2 - Metal tube bending apparatus and method - Google Patents

Description

  The present invention relates to a so-called arm turning type (arm turning type) metal pipe bending apparatus and metal pipe bending method, and more particularly to a technique for bending a metal straight pipe while locally induction heating.

Arm swivel type high-frequency bending (see, for example, Patent Documents 1 to 4) is applied to a metal pipe such as a steel pipe by applying an annular local induction heating and bending moment to sequentially bend the heating part in a moving manner. Technology. The bending moment is generated by the cooperative action of the front end side path regulation by the swing arm and the propulsion from the rear end side by the pusher.
Such a metal pipe bending apparatus is provided with a heat treatment mechanism and a bending moment applying mechanism. The heat treatment mechanism includes an inductor that inductively heats a short section in the longitudinal direction of a metal tube to be bent, a cooling mechanism that cools the heated portion, a high-frequency power source that supplies power to the inductor, a cooling mechanism and an induction The water supply equipment that supplies water to the child is provided, and the bending moment adding mechanism includes a swivel arm that regulates the arc path of the tip side of the metal pipe to be bent, and propels the metal pipe from the rear end side. There are pushers.

  A tube end clamp that holds the end of the metal tube is provided at the swivel end of the swivel arm, the upper portion of the pusher, and the like. This is a so-called tube diameter expansion clamp that is inserted into the hollow of the metal pipe to be bent and holds the inner surface of the pipe by expanding the diameter (see, for example, Patent Document 1), or the outer periphery of the metal pipe to be bent. A so-called tube outer surface grip type clamp (see, for example, Patent Documents 2 to 3) in which the metal tube is held in pressure contact with the surface, and a so-called flange gripping method in which the flange of the metal tube to be bent is held. Although it is embodied by a shape clamp (for example, refer to Patent Document 4), the entire clamp is mounted on a swivel arm or a pusher in any form. Of the tube end clamps, the front end side clamp is usually mounted so as to be relatively movable with respect to the swivel arm via a slide bed or the like. Among the tube end clamps, the rear end side clamp is fixedly attached to the pusher. However, apart from disassembly for repair or modification, it will not be separated from the wearing device in normal use.

  In such a metal pipe bending apparatus and a metal pipe bending method using the same, even if the end face of the metal pipe is grooved in advance or the flange is welded to the end of the metal pipe in advance, the metal pipe If both ends of the tube can be gripped by a clamp, not only the central bent tube portion but also the straight tube portions at both ends are continuously heated, so that uniform heat treatment can be performed together with the bending process. In addition to the pusher moving mechanism and arm turning mechanism, the metal pipe bending machine is also equipped with a heat treatment mechanism and a bending moment adding mechanism moving mechanism so that it can be adapted to differences in bending radius and straight pipe length. It is done. For example (see Patent Document 1), a drive mechanism that linearly moves an inductor, a slide bed that linearly moves a support shaft of a swivel arm on a base, and a two-stage that moves a clamp two-dimensionally on the swivel end of the swivel arm A slide bed is provided.

Japanese Patent Publication No. 2-47290 (S61-7020A) JP-A-9-57357 Japanese Patent Laid-Open No. 62-130718 JP 2004-223530 A

Thus, in the conventional metal pipe bending apparatus and method, when bending the end-finished metal pipe, a moving mechanism is provided for differences in the length of the straight pipe portion at the end of the metal pipe. Although we have dealt with it, it is not possible to cope with the difference in the shape of the end of the metal tube by the moving mechanism, so another clamp is prepared in advance for the metal tube with different pipe diameter and flange, and the clamp is replaced before processing Is done.
Specifically, among the three types of clamps described above, the use of a tube outer surface gripping clamp that requires fewer types and is easy to grip is first considered. A flange gripping type clamp was used, and other pipes with a beveled finish were used in-tube expanded diameter type clamps. Replacement of the clamp is performed by inserting and removing the mounting bolt.

  By the way, many metal tubes are first classified according to the outer diameter and then subdivided according to the inner diameter determined according to the wall thickness (see, for example, JIS G 3452). In addition to the thickness, it is also classified by the diameter and arrangement of the bolt holes. Therefore, the latter tends to increase in the latter as compared to the former in the outer pipe gripping clamp, in-pipe extended diameter clamp, and flange gripping clamp. However, conventionally, since the processing amount of a metal pipe with a flange and the like was relatively small, there was no problem in properly using the above.

  However, recently, the throughput of flanged metal pipes and grooved metal pipes has been increasing. For this reason, if the above-mentioned clamp on the outer surface of the pipe is continuously used to hold the metal pipe with the flange as it is, the shape of the flange varies so that the throughput of the metal pipe with the flange increases. As the number of clamps required increases by climbing, it is expected that an inconvenient situation will occur soon. In response to this, the above-mentioned in-pipe expanded diameter clamp is also used for gripping the flanged metal tube, and the above-mentioned in-pipe insertion expansion is performed for gripping the flanged metal tube and the grooved metal tube. It is conceivable to use a common clamp and reduce the number of clamps.

However, even if the types and number of clamps to be prepared can be reduced, the processing of large-diameter pipes that are often produced in a wide variety and in small quantities does not reduce the burden of clamping replacement work prior to processing. Since the tube insertion diameter expansion type is more difficult to align the shaft center than the gripping type, there are even parts where the work load increases. For example, a clamp that holds a large-diameter tube having an outer diameter of 114.3 mm to 318.5 mm is heavy, for example, 400 kg to 1000 kg, and it is heavy labor to replace such a clamp as a swivel arm or a pusher. Since the adjustment must be done carefully over time, the work load is large.
Therefore, it is a first technical problem to improve the metal pipe bending apparatus so that replacement of the in-pipe expanded diameter clamp becomes easy.

In addition, since flanged metal pipes require that the inclination and distortion of the flange surface be within the specified values, if the specifications are not met, the metal pipes can be bent after the flanges are re-welded. Although provided, it would be advantageous if the flange could be straightened without re-welding. Therefore, it is a second technical problem to add a device to correct the inclination and distortion of the flange surface after the heat treatment.
Furthermore, the metal pipe with flanges on both ends is also required to have a rotational difference between the two flanges within the specified value. Therefore, if the specifications are not met, the metal pipe must be re-welded after at least one flange is welded again. Although it was used for bending, it would be advantageous if the flange could be straightened without re-welding. Therefore, it is a third technical problem to further devise in order to correct the rotational difference between both flanges after the heat treatment.

Conventionally, it has been difficult to arbitrarily set the length of the straight pipe portion on the front end side of the flanged metal pipe. When the clamp is fixed to the swivel arm, depending on the length setting of the straight pipe part on the tip side, it is necessary to grip the flange part instead of the pipe part. This is because the shape of the flange is diverse.
Therefore, by further devising the structure of the tip side clamp etc. that grips the tip side of the metal tube, the length of the straight tube part on the tip side can be freely set even for a metal tube with a flange at the tip. This is the fourth technical issue.

  The metal pipe bending apparatus of the present invention (Solution 1) was created in order to solve such a problem, and includes a swivel arm that regulates the path on the tip side of the metal pipe to be bent in an arc shape. A pusher for propelling the metal tube from the rear end side, an inductor for inductively heating a short section in the longitudinal direction of the metal tube in an annular shape, and a cooling mechanism for following-cooling the heating portion. In the metal pipe bending apparatus for bending and deforming in order from the front end side to the rear end side, a front end side clamp for gripping the front end side of the metal pipe includes an arm side clamp provided at a revolving end portion of the revolving arm, and the revolving It is divided into a tube tip side clamp that can be attached to and detached from the tip side of the metal tube away from the arm, and the tube tip side clamp can be loosely inserted into the tip side of the metal tube in a reduced diameter state, and is in an expanded diameter state. In the metal tube An expansion / contraction portion that presses against an inner peripheral surface and holds the distal end side of the metal tube, and a cylindrical portion that stores the drive mechanism thereof, wherein the arm side clamp is the cylinder of the tube distal end side clamp. The tube tip side clamp is gripped by being pressed against the outer peripheral surface of the portion.

  Further, the metal tube bending apparatus of the present invention (Solution means 2) is the metal tube bending apparatus of the above solution means 1, wherein a rear end side clamp for holding the rear end side of the metal tube is provided on the pusher. A pusher-side clamp provided; and a tube rear-end side clamp that can be attached to and detached from the rear-end side of the metal tube away from the pusher, and the tube rear-end side clamp is in the reduced diameter state, the metal tube An expansion / contraction portion that can be loosely inserted on the rear end side and is in pressure contact with the inner peripheral surface of the metal tube in a diameter-enlarged state and holds the rear end side of the metal tube; and a cylindrical portion that stores the drive mechanism The pusher-side clamp is configured to press the tube rear end side clamp and press the outer peripheral surface of the cylindrical portion of the tube rear end side clamp.

  Furthermore, the metal tube bending method of the present invention (Solution means 3) is a metal tube bending method in which a metal tube is bent using the metal tube bending apparatus described in either of the solution means 1 or 2. In the processing, the front end side of the metal tube is held by the front end side clamp, and the metal tube is pushed by the pusher from the rear end side, and the front end side or the front end side of the metal tube is guided. When induction heating is performed by a child, the arm side clamp is temporarily loosened to allow the tube tip side clamp to move in the axial direction, and the tip of the metal tube is brought into contact with the arm side clamp. It is characterized by that.

Further, the metal tube bending apparatus of the present invention (solution 4) is the metal tube bending apparatus of the solution 2, wherein the rotary drive mechanism for rotating the tube rear end side clamp is the pusher side clamp or It is equipped with the pusher.
The metal tube bending method of the present invention (Solution 5) is a metal tube bending method in which a metal tube is bent using the metal tube bending apparatus of Solution 4, wherein the tip of the metal tube is bent. The tube is gripped by the front end clamp, and the metal tube is pushed by the pusher from the rear end side while the metal tube is induction heated at the front end side or the front end side by the inductor. A front end face correcting step of temporarily loosening the grip of the arm side clamp so as to allow axial movement of the front end side clamp and bringing the end of the metal tube into contact with the arm side clamp; and the front end side of the metal tube A rotation difference that operates the rotational drive mechanism while the metal tube is induction-heated with the inductor, and the rear end side of the metal tube is gripped with the rear end side clamp. Correction Characterized in that it includes a step.

  Further, the metal tube bending apparatus of the present invention (Solution means 6) includes a turning arm for restricting the path on the front end side of the metal tube to be bent in an arc shape, a pusher for propelling the metal tube from the rear end side, A metal tube bending comprising an inductor for induction heating an annular short section in the longitudinal direction of the metal tube and a cooling mechanism for cooling the heating portion in order to bend and deform the metal tube in order from the front end side to the rear end side In the processing apparatus, a rear end side clamp that holds the rear end side of the metal tube includes a pusher side clamp provided on the pusher, and a tube rear end that can be attached to and detached from the rear end side of the metal tube away from the pusher. The pipe rear end side clamp can be loosely inserted into the rear end side of the metal tube in the reduced diameter state, and is pressed against the inner peripheral surface of the metal tube in the enlarged diameter state. An expansion / contraction section for holding the rear end side of the tube; The pusher side clamp presses the outer peripheral surface of the cylindrical portion of the tube rear end side clamp and grips the tube rear end side clamp. It is characterized by being.

Further, the metal tube bending apparatus of the present invention (solving means 7) is the metal tube bending apparatus of the above-described solving means 6, wherein the rotational drive mechanism for rotating the tube rear end side clamp is the pusher side clamp or It is equipped with the pusher.
Further, the metal tube bending method of the present invention (solution 8) is a metal tube bending method of bending a metal tube using the metal tube bending apparatus of the solution 7, and in the processing, The rotary drive mechanism is configured such that the front end side of the metal tube is gripped by the front end side clamp, the rear end side of the metal tube is gripped by the rear end side clamp, and the metal tube is induction-heated by the inductor. It is characterized by operating.

Further, the metal tube bending apparatus of the present invention (Solution means 9) includes a turning arm for restricting the path on the front end side of the metal tube to be bent in an arc shape, a pusher for propelling the metal tube from the rear end side, A metal tube bending comprising an inductor for induction heating an annular short section in the longitudinal direction of the metal tube and a cooling mechanism for cooling the heating portion in order to bend and deform the metal tube in order from the front end side to the rear end side In the processing apparatus, a rotary drive mechanism for rotating the rear end side of the metal tube is provided in a rear end side clamp or the pusher for gripping the rear end side of the metal tube.
Further, the metal tube bending method of the present invention (solution 10) is a metal tube bending method of bending a metal tube using the metal tube bending apparatus of the solution 9, and in the processing, The front end side of the metal tube is gripped by the front end side clamp of the swivel end of the swivel arm, and the rear end side of the metal tube is gripped by the rear end side clamp, and the metal tube is guided by the inductor. The rotary drive mechanism is operated while heating.

  The metal tube bending apparatus according to the present invention is (the solution means 11), which is the metal tube bending apparatus of the above solution means 1, 2 and 4, wherein the arm side clamp is moved in the forward and backward direction of the pusher in the initial posture. The arm side clamp moving mechanism to be moved is provided at the turning end of the turning arm.

  In such a metal pipe bending apparatus according to the present invention (solution means 1 and 2), the pipe end clamp (front end side clamp or rear end side clamp) is a pipe end side clamp (pipe having a large diameter inserted into the pipe). It is divided into a clamp on the front end side and a clamp on the rear end side of the pipe) and a device side clamp (arm side clamp and pusher side clamp) of the pipe outer surface holding type. In addition, the apparatus-side clamp is mounted on the apparatus main body (swivel arm or pusher), while the tube end-side clamp is separated from the apparatus main body. In addition, the tube end side clamp can be freely attached to and detached from the end portion of the metal tube as a single unit, and when installed, the cylindrical portion is in a state of extending the tube end. In addition, the apparatus-side clamp does not hold the metal tube itself, but indirectly holds the end of the metal tube by holding the cylindrical portion of the tube end-side clamp.

In this way, the tube end side clamp is separated from the main body of the device and can be attached to and detached from the metal tube as a single unit, so the weight is reduced and the mounting posture is completely free. Even with an expanded-diameter clamp, it can be easily replaced with a metal tube. Moreover, the influence of the difference in the inner diameter of the metal tube is limited to the expansion / contraction portion of the tube end side clamp, and can be prevented from reaching the cylindrical portion or the device side clamp.
In addition, the metal tube with the tube end side clamp is held by holding the cylindrical part of the tube end side clamp with the device side clamp. This work is easy because of the clamp.
Therefore, according to the present invention, it is possible to realize a metal tube bending apparatus capable of easily changing the in-tube insertion enlarged diameter clamp, and as a result, the first technical problem is solved.

  In the metal tube bending method of the present invention (solution 3), the metal tube is bent using a metal tube bending device in which the tip side clamp is divided into a tube tip side clamp and an arm side clamp. Although the grip of the arm side clamp is temporarily loosened at the time of heat treatment at that time, preferably at the time of heat treatment of the tip side straight pipe part, the tube tip side clamp moves in the axial direction, and the metal tube The tip of is pressed against the arm side clamp. A force is applied to cause the tip of the metal tube to follow the contact surface of the arm side clamp, but the reaction force is absorbed by the deformation of the heating portion of the metal tube.

For this reason, as long as the contact surface of the arm side clamp is a correction reference surface such as a vertical plane, the tip (front end surface) of the metal tube is corrected. In addition, since the deformation accompanying the correction is transferred to the heat treatment part of the metal tube, large correction is difficult, but if it is a little correction, it is inconvenient by dispersing the deformation transfer part using moving heating, etc. Can be done without.
Therefore, according to the present invention, the inclination and distortion of the front end face of the metal tube can be corrected following the heat treatment by using the metal tube bending apparatus that can easily replace the in-tube expanded diameter clamp. In addition to the first technical problem, the second technical problem is also solved.

  Furthermore, in the metal tube bending method of the present invention using the metal tube bending apparatus (solution 4) of the present invention (solution 5), the inclination and distortion of the front end face of the metal tube are corrected after the heat treatment. In addition to the front end face correction process described above, the following rotation difference correction process is also executed. That is, since the rotation drive mechanism is operated while induction-heating the metal tube while holding both ends of the metal tube, the metal tube is twisted. The torsion is dispersed and fixed to each part of the metal tube with moving heating, and the total amount becomes a rotation difference between both ends of the metal tube.

Therefore, if the rotation driving mechanism is operated during the heat treatment by the amount of rotation for which the rotation difference between both ends of the metal tube is to be eliminated, the rotation difference is corrected by the total amount of rotation.
Therefore, according to the present invention, the inclination and distortion of the front end face of the metal tube can be corrected after the heat treatment by using the metal tube bending apparatus that can easily replace the in-tube expanded diameter clamp. Subsequently, the rotational difference between both ends of the metal tube can be corrected. As a result, the third technical problem is solved in addition to the first technical problem and the second technical problem.

Moreover, in the metal pipe bending apparatus of the present invention (solution means 6), the first technical problem is solved.
In the metal pipe bending apparatus and method of the present invention (solution means 7 and 8), the first technical problem and the third technical problem are solved.
In the metal pipe bending apparatus and method of the present invention (solution means 9 and 10), the third technical problem is solved.

In the metal pipe bending apparatus of the present invention (solution 11), if the arm side clamp would grip the flange part or the tube part in the initial posture, the arm side By operating the clamp moving mechanism and moving the arm side clamp to the tube tip side clamp, the tube tip side clamp of the desired shape can be held without being restricted by the length setting of the straight pipe part on the tip side. It can be gripped by the arm side clamp.
Therefore, according to the present invention, the arm-side clamp moving mechanism is provided at the turning end of the turning arm of the metal pipe bending apparatus capable of easily replacing the in-tube insertion enlarged-diameter clamp. Even if the length is arbitrarily set, it is possible to easily and reliably avoid holding the flange portion and the like, and as a result, the fourth technical problem is solved in addition to the first technical problem.

About the metal pipe bending apparatus and method of this invention, the specific form for implementing this is demonstrated by the following Examples 1-2.
The embodiment 1 shown in FIGS. 1 and 2 embodies the above-described solving means 1, 2, 6, and 11 (claims 1, 2, 6, and 11 as originally filed). The illustrated second embodiment embodies the above-described solving means 3-4, 7-10 (claims 3-4, 7-10 at the beginning of the application).
In these drawings, for the sake of simplicity, fasteners such as bases, frames and bolts, couplings such as hinges, drive sources such as electric motors, transmission members such as timing belts, electric circuits such as motor drivers, etc. The electronic circuits such as the controller are not shown in the figure, and the parts necessary for explaining the invention and the related ones are mainly shown.

  A specific configuration of Example 1 of the metal pipe bending apparatus of the present invention will be described with reference to the drawings. FIG. 1A is a schematic plan view of the metal pipe bending apparatus 20, and FIG. 1B is a schematic plan view showing a connected state / separated state of the distal end side clamps 48 + 50. 2A and 2B show the structure of the tube tip side clamp 50 of the metal tube bending apparatus 20, wherein FIG. 2A is a plan view, FIG. 2B is a cross-sectional view and a plan view of the enlarged / reduced portion 60 in a reduced diameter state, and FIG. ) Is a cross-sectional view and a plan view of the expanding / contracting portion 60 in an expanded state, and FIG.

The metal tube bending apparatus 20 (see FIG. 1A) includes guide rollers 21 and 22, heat treatment mechanisms 23 to 27, and a bending moment adding mechanism 30 + 40 for bending the metal tube 10. . The heat treatment mechanisms 23 to 27 include an inductor 23, a cooling mechanism 24, a moving mechanism 25, a high frequency power supply 26, and a water supply facility 27, and the bending moment adding mechanism 30 +40 includes a pusher 30 and a swing arm 40.
The swivel arm 40 may be composed of, for example, an L-shaped or I-shaped arm and a pair of slide beds as long as the path on the distal end side 11 of the metal tube 10 to be bent can be regulated in an arc shape (see, for example, Patent Document 1). ), And two sets of frames and rails may be arranged up and down to increase rigidity (for example, see Patent Document 2). In order to grip the distal end side 11 of the metal tube 10, a distal end side clamp 48 + 50 comprising an arm side clamp 48 and a tube distal end side clamp 50 is attached.

  Although detailed illustration is omitted, specifically, the swing arm 40 includes a vertical support shaft 41, a horizontal arm base end portion 42 supported by the base end portion, and the support shaft 41 as Y. A moving mechanism 43 that moves in the direction, a rotating mechanism 44 that rotates the support shaft 41 during arm turning, and an arm turning that is provided on the distal end side of the arm base end portion 42 and can move in the Y direction in the initial posture. The end 46 and the arm side clamp 48 attached to the arm turning end 46 are in the X direction (when the metal tube 10 that has not yet been bent is held or when the turning arm 40 is held). A bending mechanism necessary for bending deformation of the metal tube 10 is provided, which includes a moving mechanism 47 (arm-side clamp moving mechanism) that moves in the axial direction of the metal tube 10 in the initial posture, that is, the forward / backward direction of the pusher 30. Can be added to the metal tube 10 and can be positioned where the arm-side clamp 48 can grip the tube tip-side clamp 50 in the initial posture. As a result, the bending radius of the metal tube 10 and the straight tube portion on the tip-side 11 can be positioned. The length can be set arbitrarily.

The pusher 30 is provided with a rear end side clamp 32 + 33 including a pusher side clamp 32 and a pipe rear end side clamp 33 in order to hold the rear end side 12 of the metal pipe 10 to be bent. As long as the pusher 30 and the moving mechanism 31 can push the metal tube 10 from the metal tube rear end side 12 to the metal tube front end side 11, a cylinder-driven movable base (for example, see Patent Documents 3 and 4), a chain pulling type A traveling platform may be used (not shown).
Guide rollers 21, 22, an inductor 23, and a cooling mechanism 24 are disposed between the pusher 30 and the swing arm 40, and the metal tubes 10 are sandwiched between the guide rollers 21 and 22 from both sides. Undesired misalignment between the inductor 23 and the inductor 23 is prevented.

The inductor 23 is an induction coil that is slightly larger than the outer diameter of the metal tube 10 to be bent. When the metal tube 10 is loosely inserted in the hollow state and fed with power from the high-frequency power source 26, the longitudinal direction of the metal tube 10. The short section is inductively heated in a ring shape.
The cooling mechanism 24 includes an annular sprinkling tube or the like adjacent to or attached to the inductor 23. When water is supplied from the water supply equipment 27 with the metal tube 10 loosely inserted, the annular heating unit of the metal tube 10 is provided. It is designed to follow the cooling.
The moving mechanism 25 moves the inductor 23 and the cooling mechanism 24 together in the X direction, and operates when, for example, the straight tube portion on the distal end side 11 of the stopped metal tube 10 is heat-treated. (For example, refer to Patent Document 1).

  In this metal tube bending apparatus 20, the tube end clamp that grips the end portion of the metal tube 10 and the tip end clamp 48 +50 that grips the tip end side 11 of the metal tube 10 also grips the rear end side 12 of the metal tube 10. The rear end side clamp (32 + 33) can also be attached to and detached from the apparatus side clamp 48 (32) provided in the apparatus main body such as the swing arm 40 and the pusher 30 and the end 11 (12) of the metal tube 10 away from the apparatus main body. The tube end side clamp 50 (33) is divided, and the tube end side clamp 50 (33) presses against the inner peripheral surface of the metal tube 10 and holds the expansion / contraction portion, and a cylinder storing the drive mechanism The apparatus side clamp 48 (32) is configured to press the outer peripheral surface of the cylindrical portion and grip the tube end side clamp 50 (33).

  That is, the tip side clamp 48 + 50 is divided into an arm side clamp 48 provided at the arm turning end portion 46 of the turning arm 40 and a tube tip side clamp 50 that can be detached from the turning arm 40 and attached to the metal tube tip side 11. (See FIG. 1B). The tube tip side clamp 50 includes an expansion / contraction portion 60 and a cylindrical portion 51. The expandable / contractable portion 60 that can be expanded and contracted can be loosely inserted into the distal end side 11 of the metal tube 10 in the reduced diameter state, and holds the metal tube distal end side 11 in pressure contact with the inner peripheral surface of the metal tube 10 in the expanded diameter state. The cylindrical part 51 stores the drive mechanism with the enlarged diameter in a cylindrical body. The arm side clamp 48 is a tube outer surface gripping clamp that has been used most frequently in the past (see, for example, Patent Documents 2 to 3), and is pressed against the outer peripheral surface of the cylindrical portion of the cylindrical portion 51 of the tube tip side clamp 50. Thus, the tube tip side clamp 50 is gripped.

  The rear end side clamps 32 + 33 are divided into a pusher side clamp 32 provided on the pusher 30 and a pipe rear end side clamp 33 which can be detached from the pusher 30 pusher and attached to the rear end side 12 of the metal tube 10. . The tube rear end side clamp 33 can be loosely inserted into the metal tube rear end side 12 in the reduced diameter state, and press-contacts with the inner peripheral surface of the metal tube 10 in the expanded diameter state. The expansion / contraction part which hold | maintains the end side 12 and the cylindrical part which stored the drive mechanism are comprised. The tube rear end side clamp 33 is also a tube outer surface gripping type clamp, and is configured to press the tube rear end side clamp 33 in pressure contact with the outer peripheral surface of the cylindrical portion of the tube rear end side clamp 33.

  The tube tip side clamp 50 will be described in detail (see FIG. 2). The cylindrical portion 51 (see FIG. 2 (a)) is, for example, a metal cylinder 52, a drive cylinder 53 stored in the hollow thereof, and advancing and retreating with it. The forward / backward rod large diameter portion 54 to be driven and the forward / backward rod small diameter portion 55 extending beyond the forward / backward rod are formed. The tip of the forward / backward rod large diameter portion 54 and the forward / backward rod small diameter portion 55 project from the cylindrical body 52 and expand / contract. Part 60 has been reached. The expanding / contracting portion 60 (see FIGS. 2B and 2C), in order from the tip toward the cylindrical body 52, the taper member 61, a large number of diameter expanding pieces 62, a retainer 63, an intermediate slider 64, a retainer 65, and a large number of expanding and contracting portions. A diameter piece 66 and a taper member 67 are provided.

  The taper member 61 is fixed to the advancing / retreating rod small-diameter portion 55, and the diameter-expanding piece 62 is arranged radially on the tapered outer peripheral surface of the taper member 61, and is interposed between the taper member 61 and the intermediate slider 64 by the retainer 63. The taper member 67 is fixed to one end of the cylindrical portion 51, and the diameter-expanding piece 66 is radially arranged on the tapered outer peripheral surface of the taper member 67, and the taper member 67 and the intermediate slider are held by the retainer 65. 64. Further, an intermediate slider 64 is slidably fitted to the forward / backward rod small diameter portion 55 and is placed between the tip of the forward / backward rod large diameter portion 54 and one end surface of the taper member 61.

In such an expansion / contraction portion 60, when the rods 54, 55 protrude from the cylindrical portion 51, a large number of diameter expansion pieces 62, 66 are reduced in diameter (see FIG. 2B), and the rods 54, 55 are directed toward the cylindrical portion 51. When retreated, a large number of diameter-expanding pieces 62 and 66 are expanded (see FIG. 2C).
And (refer FIG.2 (d)), in the diameter-reduced state, the expansion / contraction part 60 can be loosely inserted in the front end side 11 of the metal tube 10, and after inserting in the metal tube front end side 11 in that state, the expansion / contraction part 60 is inserted. When the diameter is expanded, a large number of diameter-expanding pieces 62 and 66 are radially expanded and pressed against the inner peripheral surface of the metal tube 10, so that the expansion / contraction portion 60 holds the distal end side of the metal tube 10. ing.

  A metal tube bending method using the metal tube bending device 20 of the first embodiment will be described with reference to the drawings. FIG. 1 shows an outline of a processing procedure, (c) is a schematic plan view of a metal tube 10 and tube end side clamps 33 and 50 before mounting, and (d) is a metal tube 10 and a tube end side attached to the metal tube 10. Outline plan view of the clamps 33 and 50, (e) is a schematic plan view of the metal pipe bending apparatus 20 holding the metal pipe 10, and (f) is a schematic plan view of the metal pipe bending apparatus 20 during bending. It is. FIG. 2D is a plan view of the metal tube 10 having the groove finishing portion 13 on the metal tube distal end side 11 and the expansion / contraction portion 60 attached thereto.

  Prior to bending, the metal tube 10 is set in the metal tube bending apparatus 20. At this time, the tube front end side clamp 50 and the tube rear end side clamp 33 are detached from the arm side clamp 48 and the pusher side clamp 32, respectively. 1 (see FIG. 1C), a tube front end side clamp 50 is inserted into the front end side 11 of the metal tube 10, and a tube rear end side clamp 33 is inserted into the metal tube rear end side 12 (FIG. 1 ( d)). The tube tip side clamp 50 is inserted by reducing the diameter of the expansion / contraction part 60 and inserting it into the hollow of the tip side 11, then operating the drive cylinder 53 to advance the rods 54, 55, thereby expanding the expansion / contraction part 60. This is done by making the diameter. The tube rear end side clamp 33 is inserted in the same manner. Since the clamps 50 and 33 are comparatively light, even if they are in-tube expanded diameter clamps, they can be easily inserted into the metal tube 10. Removal is also easy. Then, the inserted metal tube 10, the tube front end side clamp 50, and the tube rear end side clamp 33 are like one long metal tube.

  Such pipe end side clamps 50 and 33 mounted metal pipe 10 is easily gripped by the bending moment addition mechanism 30 + 40 in the initial posture in the same manner as the pipe outer surface gripping clamp (see FIG. 1 (e)). That is, the cylindrical portion 51 of the tube front end side clamp 50 attached to the front end side 11 of the metal tube 10 is held by the arm side clamp 48, and the tube rear end side clamp 33 attached to the rear end side 12 of the metal tube 10. The metal tube 10 is easily set in the bending moment applying mechanism 30 + 40 by gripping the cylindrical portion of the pusher side clamp 32 to the pusher side clamp 32.

  Although detailed description is omitted, the metal tube 10 can be loosely inserted into the inductor 23 and the cooling mechanism 24 in the same manner as when the conventional tube outer surface gripping clamp is used. Further, in the initial posture, the distal end side 11 of the metal tube 10 protrudes from the inductor 23 in the X direction by a length set as a straight tube portion, and the tube distal end side clamp 50 is located at the tip, but the arm side By moving the clamp 48 in the X direction by the moving mechanism 47, the tube tip side clamp 50 can be gripped by the arm side clamp 48 easily and reliably.

  Then (see FIG. 1 (f)), while turning the inductor 23 at a high frequency and supplying heat to the cooling mechanism 24, the turning arm 40 is turned around the support shaft 41 by the rotating mechanism 44 while performing heat treatment. The pusher 30 is pushed by the moving mechanism 31 to bend the metal tube 10. At that time, although detailed description is omitted, when the heat treatment is performed to the metal tube tip side 11 and the groove finishing portion 13 to be left as the straight pipe portion, the inductor 23 is moved (see Patent Document 1) and bending is performed. Sometimes the bending moment addition mechanism 30 + 40 is activated. The length and the bending radius of the straight pipe portion are adjusted by the moving mechanisms 43, 45, and 47.

  Thus, since heat treatment and bending are performed on the metal tube 10, the metal tube 10 is removed from the metal tube bending apparatus 20 in the reverse procedure of the above-described set operation after the construction. Although the detailed description which will be repeated is omitted, the pipe end side clamps 50 and 33 are removed from the metal pipe bending apparatus 20 and then the pipe tip side clamps 50 and 33 are removed from the metal pipe 10. This is a two-step process. Removal of the metal tube 10 with the tube end side clamps 50 and 33 attached can be easily performed by releasing the gripping of the pusher side clamp 32 and the arm side clamp 48 as in the case of the tube outer surface gripping clamp. The removal of the tube tip side clamps 50 and 33 is the removal work of the in-tube expanded diameter type clamp, but the tube tip side clamps 50 and 33 are separated from the bending moment adding mechanism 30 + 40 and are light in weight so that they can be easily performed. .

  A specific configuration of the second embodiment of the metal pipe bending apparatus of the present invention will be described with reference to the drawings. FIG. 3A is a schematic plan view of the metal tube bending apparatus 80, and FIG. 3B is a diagram showing the front end side of the metal tube 70 with the front end flange 71 before the front end surface correction and holding it. It is a general | schematic top view with the front end side clamp 48 + 50.

The metal tube bending apparatus 70 is different from the metal tube bending apparatus 20 of the first embodiment described above (see FIG. 3A), in that the pusher 30 is additionally equipped with a rotation drive mechanism 81, and induction The element 23 and the cooling mechanism 24 are an inductor 82 and a cooling mechanism 83, respectively.
Moreover, the flange 71 is attached to the front end side of the metal pipe 70 to be bent, and the flange 72 is attached to the rear end side (see FIG. 4A).
In order to correct the distal end flange 71, the surface of the arm side clamp 48 on which the distal end flange 71 of the metal tube 70 abuts is formed flat and vertical (see FIG. 3B).

The rotation drive mechanism 81 is, for example, a structure in which a reduction gear or a clutch is connected to an electric motor, and a rotation controller or a rotation amount setting device is attached. If the tube rear end side clamp 33 can be rotated axially, It may be equipped with the clamp 32, and may be equipped with the pusher 30 along with the pusher side clamp 32.
For example, the inductor 82 and the cooling mechanism 83 are divided into two parts, each divided part is separated to avoid interference with the flanges 71 and 72, and the divided parts are gathered together so that the outer peripheral surface of the metal tube 70 is gathered. It is the one facing the ring.

  A metal tube bending method using the metal tube bending device 80 of the second embodiment will be described with reference to the drawings. FIG. 3 shows the straightened state of the front end face of the metal tube 70, and both (b) and (c) are schematic plan views of the front end side flange 71 of the metal tube 70 and the front end side clamp 48 + 50 holding it. Yes, among them, (b) shows the state before front end face correction, and (c) shows the state during front end face correction. 4 shows a correction state of the rotation difference between both ends 71 and 72 of the metal tube 70, (a) is a plan view of the flanged metal tube 70, and (b) is a view of the flanges 71 and 72 before rotation difference correction. An end view, (c) is a plan view of the metal tube 70 during rotational difference correction, and (d) is an end view of the flanges 71 and 72 after rotational difference correction.

  Here, although it demonstrates centering on the point which is different from the metal pipe bending method of Example 1 mentioned above, the main difference is that the inductor 82 and the cooling mechanism 83 are separated from each other when the metal pipe is set. The front end face correction process is performed after the heat treatment is started and before the bending process is started, and the rotation difference correction process is performed after the front end face correction process.

The metal tube is set (see FIG. 3B), the two inductors 82 and the cooling mechanism 83 are separated from each other to the left and right, and the above-described metal tube setting operation is completed. After the gripping is performed by the additional mechanism 30 + 40, the inductor 82 and the cooling mechanism 83 are both brought close to and united. As a result, the inductor 82 and the cooling mechanism 83 annularly surround the short section in the longitudinal direction of the metal tube 70 without being obstructed by the front end side flange 71 and the rear end side flange 72.
When the front end surface correction step is performed after the metal tube setting step, the front end side flange 71 is brought into contact with the contact surface 49 of the arm side clamp 48 in advance when the metal tube 70 is set in preparation for the front end surface correction step. In this state, the cylindrical portion 51 of the tube tip side clamp 50 is preferably held by the arm side clamp 48 (see FIG. 3B).

  The front end surface correction step (see FIG. 3C) is preferably performed during the heat treatment of the straight tube portion on the distal end side of the metal tube 70, but is not limited to the distal end side. The heat treatment may be performed when the side is heat-treated. Specifically, while the metal tube 70 is pushed by the pusher 30 from the rear end side, the leading end side or the front end side of the metal tube 70 is induction-heated by the inductor 82. The arm side clamp 48 is temporarily loosened. It is sufficient that the cylindrical portion 51 of the tube tip side clamp 50 can be moved slightly in the axial direction in the arm side clamp 48 so that the vertical movement of the tube tip side clamp 50 and the metal tube 70 can be ignored. Stay. Although it may be performed with the inductor 82 fixed, it is preferable to perform the movement while moving the inductor 82, and it may be single-shot, but it is desirable to be continuous or intermittent. In this step, the front end flange 71 is pressed against the contact surface 49 to correct the inclination of the front end flange 71, and the deformation is transferred to the annular heating portion 73. From the viewpoint of dispersing the pass-through deformation. It is desirable to perform the gripping relaxation continuously or intermittently while moving and heating.

  The rotation difference correction process (see FIG. 4) is performed with the front end side of the metal tube 70 held by the front end side clamp 48 + 50 and the rear end side of the metal tube 70 held by the rear end side clamp 32 + 33. When the straightening process is performed, it is performed after that, but when the front end face straightening process is not performed, it may be performed any time after the metal tube is set, and the metal tube 70 is induction-heated by the inductor 82. However, it is performed by operating the rotation drive mechanism 81. As a specific example, assuming that the rotational difference θ1 between the front end side flange 71 and the rear end side flange 72 exceeds the allowable value in the specification (see FIG. 4B), in this case, it is slightly larger than the excess amount. The tube rear end side clamp 33 and consequently the rear end side flange 72 are rotated to the rotation difference elimination side by the rotation drive mechanism 81 by the total rotation amount θ2 (see FIG. 4C).

  Then, since the torsional deformation with a total rotation amount of less than θ2 is fixed to the annular heating portion 73 of the metal tube 70, the rotation difference θ3 between the front end side flange 71 and the rear end side flange 72 in the metal tube 70 that has undergone the rotation difference correction process. (See FIG. 4D) is smaller than the rotation difference θ1 before correction by a little less than the total rotation amount θ2, and falls within the allowable range. Even in this rotational difference correction, it is desirable to disperse the torsional deformation passed from the flange to the cylinder, so constant speed rotation during moving heating is fundamental, but rotation occurs during heat treatment of the straight part and heat treatment of the bending part. The speed may be switched, and in that case, it is preferable to increase the rotational speed at the straight portion and decrease the rotational speed at the bent portion.

[Others]
In the front end surface correction step of the second embodiment, the correction of the inclination of the flange surface has been described. However, if the front end surface is corrected while the flange is also heated, the distortion of the flange surface is corrected in addition to the inclination of the flange surface. Sometimes. Further, the correction of the front end face is not limited to the flange, and is often effective even when the front end face (tip) has another shape, for example, when the groove finish is performed. In addition, to give one numerical example of the correction target one by one, the inclination of the flange surface is 1/250 or less, the inclination of the groove part is 0.8 mm or less, the distortion of the flange surface is 2 mm or less, and the rotational difference between the flanges at both ends is the bolt There is a distance of 1.6 mm or less in the distance of the insertion hole.

  The metal pipe bending apparatus and bending method of the present invention are typically applied to steel pipes, but other metal pipes, for example, metals made of materials such as stainless steel, aluminum-based, titanium-based, cast steel, cast iron, etc. It can also be applied to tubes.

In Example 1 of the present invention, (a) is a schematic plan view of a metal tube bending apparatus, (b) is a schematic plan view showing a coupling state / separation state of a distal end side clamp, and (c) is a metal tube and before mounting. (D) is a schematic plan view of a metal tube and a tube end side clamp attached thereto, and (e) is a schematic plan view of a metal tube bending apparatus holding the metal tube. FIG. 5 (f) is a schematic plan view of a metal pipe bending apparatus during bending. The structure of the tube tip side clamp of a metal tube bending apparatus is shown, (a) is a plan view, (b) is a sectional view and a plan view of the expanded / contracted portion in the reduced diameter state, and (c) is the expanded / contracted portion in the expanded diameter state. Sectional drawing and top view, (d) is a top view of the metal tube front end side and the expansion / contraction part inserted in it. Regarding Example 2 of the present invention, (a) is a schematic plan view of a metal tube bending apparatus, (b) is a schematic plan view of a metal tube tip side before front end surface correction and a tip side clamp holding it, (C) is a schematic plan view of the front end side of the metal tube during front end surface correction and the front end side clamp holding it. The correction state of the rotation difference of the both ends of a metal tube is shown, (a) is a top view of a metal tube with a flange, (b) is an end view of the flange before rotation difference correction, and (c) is a metal tube during rotation difference correction. (D) is an end view of the flange after rotational difference correction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Metal pipe, 11 ... Metal pipe front end side, 12 ... Metal pipe rear end side, 13 ... Groove finish part,
20 ... Metal tube bending apparatus, 21, 22 ... Guide roller, 23 ... Inductor,
24 ... Cooling mechanism, 25 ... Moving mechanism, 26 ... High frequency power supply, 27 ... Water supply equipment,
30 ... pusher, 31 ... moving mechanism,
32 ... Pusher side clamp (device side clamp, rear end side clamp),
33 ... Pipe rear end side clamp (tube end side clamp, rear end side clamp),
40 ... swivel arm (rotating arm, bending arm),
41 ... support shaft, 42 ... arm base end, 43 ... moving mechanism, 44 ... rotating mechanism,
45 ... moving mechanism, 46 ... arm turning end, 47 ... moving mechanism,
48 ... arm side clamp (device side clamp, tip side clamp), 49 ... contact surface,
50 ... Tube tip side clamp (tube end side clamp, tip side clamp),
51 ... Cylindrical part, 52 ... Cylinder, 53 ... Drive cylinder,
54 ... Advancing / retreating rod large diameter part, 55 ... Advancing / retreating rod small diameter part,
60 ... Expanded portion, 61 ... Taper member, 62 ... Expanded diameter piece, 63 ... Retainer,
64 ... Intermediate slider, 65 ... Retainer, 66 ... Diameter expansion piece, 67 ... Tapered member,
70 ... Metal pipe, 71 ... Front end side flange, 72 ... Rear end side flange, 73 ... Annular heating section,
80 ... Metal tube bending apparatus, 81 ... Rotary drive mechanism, 82 ... Inductor, 83 ... Cooling mechanism

Claims (3)

A swivel arm that regulates the path on the front end side of the metal pipe to be bent in an arc shape, a pusher that propels the metal pipe from the rear end side, and an inductor that induction-heats the short section in the longitudinal direction of the metal pipe in an annular shape A metal tube bending apparatus that includes a cooling mechanism for following and cooling the heating unit, and further bends and deforms the metal tube in order from the front end side to the rear end side, and further includes a front end that grips the front end side of the metal tube The side clamp is divided into an arm side clamp provided at the turning end of the turning arm and a tube tip side clamp that can be attached to and detached from the tip side of the metal tube away from the turning arm. The clamp can be loosely inserted into the distal end side of the metal tube in the contracted state, and in the expanded state, the expanded / contracted portion that presses against the inner peripheral surface of the metal tube and holds the distal end side of the metal tube, and its drive mechanism And a cylindrical portion storing The arm side clamp is in contact with the outer peripheral surface of the cylindrical portion of the tube tip side clamp and grips the tube tip side clamp using a metal tube bending apparatus, and flanges are provided at both ends. When bending metal pipes with
The front end side of the metal tube is gripped by the front end side clamp, and the metal tube is pushed by the pusher from the rear end side, and the front end side or the front end side of the metal tube is induction heated by the inductor. Sometimes, the grip of the arm side clamp is temporarily loosened so as to allow the axial movement of the tube tip side clamp, and the flange of the tip of the metal tube is brought into contact with the vertical plane of the arm side clamp. A method of bending a metal tube, wherein the perpendicularity of the flange at the tip of the metal tube is corrected. A swivel arm that regulates the path on the front end side of the metal pipe to be bent in an arc shape, a pusher that propels the metal pipe from the rear end side, and an inductor that induction-heats the short section in the longitudinal direction of the metal pipe in an annular shape A metal tube bending apparatus that includes a cooling mechanism for following and cooling the heating unit, and further bends and deforms the metal tube in order from the front end side to the rear end side, and further includes a front end that grips the front end side of the metal tube The side clamp is divided into an arm side clamp provided at the turning end of the turning arm and a tube tip side clamp that can be attached to and detached from the tip side of the metal tube away from the turning arm. The clamp can be loosely inserted into the distal end side of the metal tube in the contracted state, and in the expanded state, the expanded / contracted portion that presses against the inner peripheral surface of the metal tube and holds the distal end side of the metal tube, and its drive mechanism And a cylindrical portion storing The arm-side clamp is in pressure contact with the outer peripheral surface of the cylindrical portion of the tube tip side clamp and grips the tube tip side clamp, and the rear end grips the rear end side of the metal tube. The side clamp is divided into a pusher side clamp provided on the pusher and a tube rear end side clamp that can be attached to and detached from the rear end side of the metal tube away from the pusher, and the tube rear end side clamp is In the reduced diameter state, it can be loosely inserted into the rear end side of the metal tube, and in the expanded diameter state, an expansion / contraction portion that presses against the inner peripheral surface of the metal tube and holds the rear end side of the metal tube, and a drive mechanism thereof The pusher side clamp presses the outer peripheral surface of the cylindrical portion of the tube rear end side clamp and grips the tube rear end side clamp, Rotate the tube rear end clamp With rotation drive mechanism the pusher side clamps or metal pipe bending apparatus is equipped with the pusher, a metal pipe bending method for bending a metal tube having a flange at both ends,
The front end side of the metal tube is gripped by the front end side clamp, and the metal tube is pushed by the pusher from the rear end side, and the front end side or the front end side of the metal tube is induction heated by the inductor. A front end face correction step of temporarily loosening the grip of the arm side clamp to allow axial movement of the tube tip side clamp and bringing the tip of the metal tube into contact with the arm side clamp;
The front end side of the metal tube is gripped by the front end side clamp, and the rear end side of the metal tube is gripped by the rear end side clamp, and then the rotational drive is performed while the metal tube is induction heated by the inductor. A rotation difference correction step of correcting an angular difference between both flanges of the metal tube by rotating the shaft of the rear end of the metal tube by operating a mechanism;
The metal pipe bending method characterized by including. A swivel arm that regulates the path on the front end side of the metal pipe to be bent in an arc shape, a pusher that propels the metal pipe from the rear end side, and an inductor that induction-heats the short section in the longitudinal direction of the metal pipe in an annular shape A metal tube bending apparatus that includes a cooling mechanism for following and cooling the heating unit, and further bends and deforms the metal tube in order from the front end side to the rear end side, and further includes a front end that grips the front end side of the metal tube The side clamp is divided into an arm side clamp provided at the turning end of the turning arm and a tube tip side clamp that can be attached to and detached from the tip side of the metal tube away from the turning arm. The clamp can be loosely inserted into the distal end side of the metal tube in the contracted state, and in the expanded state, the expanded / contracted portion that presses against the inner peripheral surface of the metal tube and holds the distal end side of the metal tube, and its drive mechanism And a cylindrical portion storing Rear and than, the arm clamp, pressed against the outer peripheral surface of the cylindrical portion of the tube distal end clamp is intended to grip the tube distal side clamp, for grasping the rear end of the metal tube The side clamp is divided into a pusher side clamp provided on the pusher and a tube rear end side clamp that can be attached to and detached from the rear end side of the metal tube away from the pusher, and the tube rear end side clamp is In the reduced diameter state, it can be loosely inserted into the rear end side of the metal tube, and in the expanded diameter state, an expansion / contraction portion that presses against the inner peripheral surface of the metal tube and holds the rear end side of the metal tube, and a drive mechanism thereof The pusher side clamp presses the outer peripheral surface of the cylindrical portion of the tube rear end side clamp and grips the tube rear end side clamp, Rotate the tube rear end clamp Upon rotation drive mechanism using the pusher side clamps or metal pipe bending apparatus is equipped with the pusher, bending processing a metal tube having a flange at both ends,
The front end side of the metal tube is gripped by the front end side clamp, and the rear end side of the metal tube is gripped by the rear end side clamp, and then the rotational drive is performed while the metal tube is induction heated by the inductor. A metal tube bending method characterized in that by operating a mechanism, the angle difference between both flanges of the metal tube is corrected by rotating the rear end of the metal tube.

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