JP6205239B2 - Metal pipe bending apparatus, meander pipe manufacturing method, and serpentine pipe - Google Patents

Description

  The present invention relates to a metal pipe bending apparatus, a meander pipe manufacturing method, and a serpentine pipe that can bend a metal pipe by 180 ° with a small radius even when the straight pipe portion after bending is long. .

  As a metal tube having a straight tube portion and a curved tube portion, for example, there is a meandering tube (boiler tube) used in a power generation device, a boiler or the like. A boiler tube is exposed to high-temperature combustion gas in, for example, a thermal power plant, an incinerator, a coke dry fire extinguishing facility, etc., and a fluid such as circulating water is circulated inside the boiler tube, so that the combustion gas passes through the circulating water. The turbine is driven by the heat of the heat. A boiler tube having a shape in which a straight pipe is meandered by bending a plurality of 180 ° bendings in order to increase the heat transfer area is known. This boiler tube is formed in a shape in which a single straight pipe is meandered by a plurality of 180 ° bending processes, but actually, it is formed by connecting a plurality of stick-type (J-type) conduits. (For example, refer to Patent Document 1). For example, a boiler tube having five curved pipe portions is formed by welding and connecting five stick-type conduits and one straight pipe.

  Thus, in a boiler tube having five curved pipe portions, it is necessary to manufacture five stick-type conduits and to connect five stick-type conduits to one straight pipe, which requires a large number of steps. Since the working time is long, a means for forming a boiler tube having, for example, five curved pipe parts by bending one straight pipe continuously in order to reduce the man-hour, shorten the working time, and reduce the cost. It is desired.

  By the way, as a bending apparatus for bending a metal tube, a clamp body that holds a linear metal tube, a front part of a clamp body and a front part of the bending part of the metal tube, and a metal pipe are used. There are known ones that include a bending arm that can turn around a rotation axis positioned on the side of the side, a heating means that heats the bending portion, and a moving means that advances the clamp body (for example, a patent) Reference 2). If this bending apparatus is used, a stick-type (J-type) conduit can be manufactured. However, the propulsion device, which is a moving means for advancing the clamp body, is a hydraulic cylinder disposed on both sides of the metal tube. In order to move the clamp body forward by the bending of the metal pipe with a small radius of 180 °, if the straight pipe portion after bending is long, the hydraulic cylinder and the support member that supports the hydraulic cylinder are covered. The metal tube cannot be bent due to the obstruction of the bracket.

JP 9-316622 A JP 2006-326667 A

  The problem to be solved by the present invention is that a metal pipe bending apparatus and a meander pipe manufacturing method capable of bending a metal pipe with a small radius of 180 ° even if the straight pipe portion after bending is long. And providing a serpentine tube.

In order to solve the above-described problems, a metal tube bending apparatus according to the present invention includes a clamp body that holds a straight metal pipe, a front portion of the clamp body, and a front portion of the metal tube. gripping the, arranged on one side portion relates to the aforementioned metal tube, and upper end pivotable bending arm about the lower rotary shaft than the metal tube, and a heating means for heating the bending portion, the metal tube Supporting means for supporting the clamp body movably in the axial direction of the metal tube, and a region on the side of the metal tube on the side opposite to the rotating shaft below the metal tube. a mobile unit according to arranged a ball screw for moving the clamp member, the ball screw, positioned below the said metal tube in the region, and Do not interfere with the support means of the clamping member Position and a moving means which is disposed close to the metal tube, by advancing the clamping member while heating the bending point of the metal tube is gripped by the clamp body and the bending arm, the bending The metal tube is bent and deformed around the rotation axis by turning an arm and applying a bending moment to the bending portion.

  As described above, the moving means for moving the clamp body is arranged in the region below the metal tube and on the side opposite to the rotation axis, so that the metal tube is bent by 180 ° with a small radius. In this case, even if the length of the straight pipe portion after bending is long, the moving means does not get in the way. Therefore, even if the length of the straight pipe portion after bending is long, the metal pipe can be bent with a small radius of 180 °.

  In the present invention, the moving means is a ball screw whose driving member moves the clamp body. The ball screw has a short distance in the horizontal direction and a distance in the height direction between the axis of the straight pipe portion and the axis of the ball screw. It may be arranged close to the metal tube. Moreover, the location which hold | grips the metal tube of a clamp body and a bending arm may be formed with the clamp member made from aluminum.

Moreover, in order to solve the said subject, the manufacturing method of the meandering pipe | tube which concerns on this invention uses the above-mentioned bending process apparatus of a metal pipe, and makes several straight pipe parts and curved pipe parts from one linear metal pipe. with the manufacture of the serpentine tubes unconnected, and the bent tube portion forming step of bending the machining spot to advance the metal tube while heating the plastically deformable temperature of the metal tube 180 ° bending of the metal tube Before forming the next bent pipe part after forming one bent pipe part, the metal pipe is fed forward, rotated and rotated by 180 ° around the axis and reversed, and the bent pipe part is formed. A method of manufacturing a meandering tube in which the metal tube is meandered by repeatedly performing a step and an inversion step , wherein the one straight metal tube has a self-fluxing alloy film on a portion that becomes a straight tube part after bending. A self-fluxing alloy that is formed and is heated and remelted at the bending portion. A metal tube formed in a portion having a metal powder layer and a portion not having the metal powder layer, and the bent tube portion forming step is capable of plastic deformation of the metal tube at a bending portion having the metal powder layer. And a first bent tube portion forming step of bending the metal tube by 180 ° while heating at a temperature at which the metal powder layer can be heated and remelted, and the plasticity of the metal tube at the bent portion where the metal powder layer is not provided A second bent pipe portion forming step of bending the metal pipe by 180 ° while heating to a deformable temperature.

  In addition, as one straight metal tube, a metal powder layer containing a self-fluxing alloy that is heated and remelted is formed in a portion that becomes a straight tube portion after bending, and the bending portion is a metal powder layer Using a metal tube formed in a part having a metal powder layer and a part not having a metal powder layer, the part that becomes the straight pipe part after the bending process having the metal powder layer is heated at a temperature at which the metal powder layer can be heated and remelted. It has a straight pipe part forming step of forming a self-fluxing alloy film by advancing the metal pipe while heating, and the bent pipe part forming step is capable of plastic deformation of the metal pipe at the bending portion having the metal powder layer and the metal powder. The first bent tube portion forming step of bending the metal tube by 180 ° while heating at a temperature at which the layer can be remelted, and at a bending position where the metal powder layer is not provided, the metal tube can be plastically deformed. Bend the metal tube 180 ° while heating You may make it consist of a 2nd curved pipe part formation process.

  Further, as one straight metal tube, a self-fluxing alloy film is formed on a portion that becomes a straight pipe part after bending, and a metal powder containing a self-fluxing alloy that is heated and remelted at a bending portion Using the metal tube in which the layer is formed, the bent tube portion forming step is performed while heating the bent portion at a temperature at which the metal tube can be plastically deformed and the metal powder layer can be heated and remelted. You may make it bend 180 degree | times.

  In addition, as a single straight metal tube, a metal tube in which a metal powder layer containing a self-fluxing alloy to be heated and remelted is formed, and a portion that becomes a straight tube part after bending is made of metal powder. It is equipped with a straight pipe part forming process that forms a self-fluxing alloy film by advancing the metal pipe while heating at a temperature at which the layer can be heated and remelted. The metal tube may be bent 180 ° while being heated at a temperature at which the metal powder layer can be heated and remelted.

  According to the present invention, even if the length of the straight pipe portion after bending is long, the metal pipe can be bent by 180 ° with a small radius.

It is a perspective view which shows an example of the bending apparatus of the metal pipe of embodiment which concerns on this invention. It is a schematic plan view which shows the principal part structure of the bending apparatus of the metal pipe of this embodiment. It is an AA arrow directional cross-sectional view in FIG. It is a top view which shows an example of the meander pipe | tube of embodiment which concerns on this invention.

  Hereinafter, an embodiment of a metal pipe bending apparatus according to the present invention will be described with reference to the accompanying drawings. As shown in FIG. 1 to FIG. 3, the metal tube bending apparatus 1 of the present embodiment bends one straight metal tube 10, for example, and a plurality of such as shown in FIG. 4, for example. An unconnected meandering pipe (boiler tube) 8 having a straight pipe portion 8a and a curved pipe portion 8b can be formed. As the metal pipe 10, for example, a steel pipe having a diameter of about 30 to 80 mm used in a power generation device, a boiler, or the like can be used.

  As shown in FIGS. 1 to 3, the metal pipe bending apparatus 1 relates to a clamp body 2 that holds a straight metal pipe 10, a front side of a bending portion of the metal pipe 10, and a metal pipe 10. A bending arm 3 that can be turned around a rotation shaft 30 positioned on one side, a heating means 4 that heats the metal tube 10, and a clamp body 2 that is provided below the metal tube 10 is attached to the metal tube 10. A supporting means 5 for supporting the movable body in the axial direction, and a moving means 6 for moving the clamp body 2 disposed in a region below the metal tube 10 and on the side opposite to the rotating shaft. Yes. The clamp body 2, the bending arm 3, the heating means 4, the support means 5 and the moving means 6 are provided on the base 11.

  The base 11 is preferably formed to be robust so that the shaft of the metal tube 10 does not move when the metal tube 10 is bent. The base 11 is formed long in the front-rear direction using, for example, a frame material having a substantially rectangular cylindrical cross section made of metal such as aluminum or steel. The base 11 includes an installation base 12 installed on the floor, a first fixing base 13 having a substantially rectangular cylindrical cross section that is disposed above the installation base 12 and is long in the front-rear direction, and a front end of the first fixing base 13. And a second fixed base 14 connected to each other.

  On the first fixed base 13, a rail 51 is provided as support means 5 that supports the clamp body 2 so as to be movable in the axial direction of the metal tube 10 held by the clamp body 2. A concave moving member 52 that moves along the rail 51 is engaged with the rail 51. The moving member 52 is a kind of wheel, and is attached to the lower surface of the flat moving body 53 that is long in the front-rear direction. The clamp body 2 is fixed to the upper surface of the moving body 53. Thus, the clamp body 2 can move on the rail 51 along the rail 51, that is, move in the axial direction of the metal tube 10. The length of the rail 51 is arbitrarily set from the range in which the movable body 53, that is, the clamp body 2 can be advanced to bend the metal tube 10 by 180 ° bending.

  The clamp body 2 holds the linear metal tube 10 horizontally, for example, and a well-known one, for example, a member provided with a pair of upper and lower clamp members 21 and 22 can be used. The clamp body 2 includes a frame body 20 formed in a substantially rectangular tube shape into which the metal tube 10 is inserted, and the frame body 20 is fixed on the moving body 53. A bottom portion of the frame body 20 is formed as a lower clamp member 22 with a recess provided on the upper surface. Above the lower clamp member 22 in the frame body 20, an upper clamp member 21 that is supported so as to be movable in the vertical direction with respect to the lower clamp member 22 and that has a recess on the lower surface is provided.

  A hydraulic cylinder 23 that is a moving means for moving the upper clamp member 21 up and down is provided on the upper portion of the frame body 20. Thus, the metal tube 10 can be gripped by the lower clamp member 22 and the upper clamp member 21 by lowering the upper clamp member 21. At this time, it is preferable that the clamp body 2 is formed of a clamp member made of aluminum at a portion where the metal tube 10 is directly gripped. That is, the concave portions of the upper and lower clamp members 21 and 22 may be formed of aluminum, or the metal tube 10 may be held by the upper and lower clamp members 21 and 22 via a pair of concave aluminum clamp members 27. May be.

  A guide portion 7 is provided on the second fixed base 14. The guide portion 7 guides the movement of the linear metal tube 10 gripped by the clamp body 2 in the axial direction, and is formed by, for example, a pair of left and right guide rollers 71 and 72 with a central portion constricted. One of the pair of left and right guide rollers 71, 72, for example, the right guide roller 72 is formed to be movable left and right by a handle 73. Thereby, even if the diameter of the metal tube 10 differs, the metal tube 10 can be guided in the axial direction.

  A bending arm 3 is provided in front of the guide portion 7 of the second fixed base 14. The bending arm 3 is provided so as to be able to turn around a rotating shaft 30 positioned on one side, for example, the right side of the metal tube 10. The rotating shaft 30 is rotatably supported by the rotating shaft support portion 15 in a state extending in the height direction (vertical direction). The rotating shaft support 15 is attached to the second fixed base 14 so as to be movable in the left-right direction, that is, the position in the left-right direction can be adjusted. Thereby, the position of the rotating shaft 30 with respect to the metal tube 10 can be adjusted.

  The bending arm 3 is formed of an arm part 31 attached to the rotary shaft 30 and a clamp part 32 attached to the arm part 31. The clamp part 32 grips the linear metal tube 10, and, for example, a clamp provided with a pair of left and right clamp members 33 and 34 can be used. For example, the clamp portion 32 is formed in an L shape, and a vertical portion extending in the height direction is formed by a pair of left and right clamp members 33 and 34, and the upper end of one clamp member, for example, the left clamp member 33 is the other clamp member. For example, it is rotatably provided at the upper end of the right clamp member 34 so that the metal tube 10 can be gripped and released. The left and right clamp members 33 and 34 are preferably formed of aluminum clamp members at positions where the metal tube 10 is directly gripped. That is, the concave portions of the left and right clamp members 33 and 34 may be formed of aluminum, or the metal tube 10 is gripped by the left and right clamp members 33 and 34 via a pair of concave aluminum clamp members 29. May be. Further, a clamping member 35 such as a hydraulic cylinder for holding a state in which the metal tube 10 is held by the pair of left and right clamp members 33 and 34 is provided in a horizontal portion of the clamp portion 32 extending in the horizontal direction.

  The arm portion 31 can hold the metal tube 10 held by the clamp body 2 and guided by the guide portion 7 by the clamp portion 32, and advance the metal tube 10 from this state to perform a bending process of 180 ° bending. It is for turning the clamp part 32 so that it can do. In other words, the clamp part 32 can rotate and move between a gripping position where the metal tube 10 can be gripped and a 180 ° bending end position rotated 180 degrees around the rotary shaft 30 from the gripping position. It is connected to.

  For example, the arm portion 31 is attached to the rotating body 36 integrally provided with the rotating shaft 30, the intermediate body 38 attached to the rotating body 36 via the first arm 37, and the intermediate body 38. And a second arm 39 fixed to the clamp portion 32. The intermediate body 38 is formed in a rectangular parallelepiped shape, and a rod-shaped first arm 37 that is rectangular in cross section and extends in the horizontal direction is fixed to one side surface. The 1st arm 37 is attached to the rotary body 36 so that length adjustment is possible. Thereby, the position of the clamp part 32 in the horizontal direction can be adjusted. Further, in combination with the adjustment of the position of the rotary shaft 30 with respect to the metal tube 10, the radius of bending of the metal tube 10 can be adjusted. The second arm 39 is formed in a rod shape having a rectangular cross section and extending in the height direction, and the upper end is fixed to the lower surface of the clamp portion 32. The 2nd arm 39 is attached to the intermediate body 38 so that length adjustment is possible. Thereby, the position of the clamp part 32 in the height direction can be adjusted.

  The heating means 4 includes a ring-shaped heating body 41 that is disposed between the holding position of the clamp portion 32 of the bending arm 3 and the guide portion 7 and into which the metal tube 10 is inserted. The heating body 41 is an induction coil that is energized with a high-frequency current for inductively heating the metal tube 10 inserted in the heating body 41. The heating body 41 is formed so that the metal tube 10 can be heated to a temperature at which the metal powder layer can be heated and melted and a temperature at which the metal tube 10 can be plastically deformed.

  The moving means 6 moves the clamp body 2 in the front-rear direction (the axial direction of the metal tube 10), and can move the clamp body 2 forward to bend the metal tube 10. The moving means 6 includes a single ball screw 61 and a drive motor 62 which are moving members that actually move the clamp body 2. For example, the ball screw 61 is formed slightly longer than the rail 51 and is provided in parallel with the rail 51. The position of the ball screw 61 is below the metal tube 10 held by the clamp body 2 and on the opposite side of the rotating arm 30 of the bending arm 3. The position of the ball screw 61 is preferably disposed close to the metal tube 10 such that the horizontal distance and the height distance between the axis of the metal tube 10 and the ball screw 61 are reduced. In the present embodiment, the ball screw 61 is disposed in the vicinity of the lower left corner when the frame body 20 of the clamp body 2 is formed in a rectangular shape, for example.

  One end (front end) of the ball screw 61 is rotatably supported by a bearing 63 provided in front of the first fixed base 13 and in the vicinity of the front end of the rail 51. The vicinity of the other end (rear end) of the ball screw 61 is rotatably supported by a bearing 64 provided behind the first fixed base 13 and in the vicinity of the rear end of the rail 51. A driven pulley 65 is attached to the rear end of the ball screw 61. That is, when the ball screw 61, the bearings 63 and 64 that support the ball screw 61, and the driven pulley 65 are bent at 180 ° with a small radius of the metal tube 10, the length of the straight pipe portion 8a after bending is long. It is placed in a position that does not get in the way even if it is long.

  The driven pulley 65 is connected to a drive pulley 67 via a belt, a chain 66, or the like. The drive pulley 67 is attached to the rotation shaft of a drive motor 62 that is provided on the left side of the installation table 12 and can rotate forward and backward. The ball screw 61 is screwed into the engaging portion 25 provided near the lower left corner of the clamp body 2. Thereby, the ball screw 61 is rotated by the drive of the drive motor 62, and the clamp body 2 is moved along the rail 51. In FIG. 3, reference numeral 69 indicates a guide pulley that guides the chain 66.

  Next, using the metal pipe bending apparatus 1 configured as described above, a single straight metal pipe 10 is provided with a plurality of straight pipe portions 8a and bent pipe portions 8b, and also has a self-fluxing alloy film. The case of forming a meandering pipe for connection will be described.

  As one straight metal pipe 10, for example, a self-fluxing alloy film 9 is formed on a portion that becomes a straight pipe portion 8a after bending, and a self-fluxing alloy in which the bending portion is heated and remelted. The metal tube formed in the part which has a metal powder layer containing and the part which does not have a metal powder layer is used.

  As the self-fluxing alloy, a well-known alloy can be used. For example, a Ni-based alloy, Ni-Cr-based alloy, or Co-based alloy provided with self-fluxing by blending B or Si as flux generating components, or these An alloy containing WC cermet or the like may be used for the purpose of improving wear resistance. The thickness of the coating is not particularly limited, and is set to about 0.5 to 3 mm after the heat remelting treatment, for example. The metal powder layer can be formed using, for example, a thermal spraying machine. As the thermal spraying machine, known ones such as a gas flame spraying machine, a plasma spraying machine, and an HVOF thermal spraying machine can be used. For the formation of the self-fluxing alloy film 9 in the portion that becomes the straight pipe portion 8a after the bending (heating and remelting treatment of the metal powder layer), for example, a publicly known one may be used, or the bending apparatus of the present embodiment 1 may be used. Further, since the self-fluxing alloy film 9 is a dense and hard film with high adhesion, a uniform thickness and a smooth surface, it is optimal as a film for a meandering tube (boiler tube).

  A straight metal tube 10 on which a metal powder layer and a self-fluxing alloy film are formed is connected between the upper and lower clamp members 21 and 22 of the clamp body 2, between the guide rollers 71 and 72 of the guide portion 7, and the heating body 41. It passes sequentially and is mounted on the lower clamp member 22 of the clamp body 2. The upper clamp member 21 is lowered and the metal tube 10 is held by the upper and lower clamp members 21 and 22 of the clamp body 2. The front of the metal tube 10 is held by a pair of left and right clamp members 33 and 34 of the clamp portion 32 of the bending arm 3. These two grips are performed so as to sandwich a bending portion where the metal tube 10 is bent, and the bending portion can be sufficiently heated by the heating body 41.

  After gripping, the bending portion of the metal tube 10 is heated in an annular shape by the heating body 41. This heating is performed at a temperature at which the metal tube 10 can be plastically deformed and the metal powder layer can be heated and remelted at the bending portion where the metal powder layer is provided, and at the bending portion where the metal powder layer is not provided. It is performed at a temperature capable of plastic deformation of 10. While performing this heating, the drive motor 62 is driven to advance the clamp body 2. At this time, the clamp body 2 is positioned on the rear side of the rail 51. As the clamp body 2 advances, the bending arm 2 pivots about the rotation shaft 30 and a bending moment acts on the bending portion, so that the metal tube 10 is bent and deformed about the rotation shaft 30. That is, the metal tube 10 is gradually bent to the right side. When this bending is performed 180 °, the forward movement of the clamp body 2 is stopped. The heating of the heating body 41 to the metal tube 10 may be stopped when the clamp body 2 stops moving forward, or the driving motor 62 is stopped when the heating of the metal tube 10 is sufficiently performed for bending. You may stop before.

  As a result, the metal pipe 10 is formed with a bent pipe portion 8b bent 180 ° to the right. At this time, when the bent portion has a metal powder layer, the outer surface of the bent tube portion 8b is heated at a temperature at which the metal powder layer can be heated and remelted when the bending is performed. Since it is performed, the metal powder layer is heated and remelted to form the self-fluxing alloy film 9 (first bent tube portion forming step). Moreover, when a bending process location does not have a metal powder layer, only a bending process is performed (2nd curved pipe part formation process). Thus, one curved pipe portion 8b is formed. For example, when the meandering tube 8 shown in FIG. 4 is formed, the left three bent tube portions 8b are formed with a self-fluxing alloy film 9 on the surface, and the two right bent tube portions 8b are formed on the surface. The self-fluxing alloy film 9 is not formed.

  In order to perform the next bending process, the heated body 41 is sufficient as a bending part where the bending of the bending arm 3 is released and the metal pipe 10 is advanced along the axial direction and the bending process is performed next. The metal tube 10 is moved so that it can be heated. That is, the metal tube 10 is fed forward. This idle feeding may be performed using the clamp body 2 or may be performed manually or using another device with the clamp body 2 released. After the movement of the metal tube 10, the metal tube 10 is rotated by 180 ° around the axis of the straight metal tube 10 before the bending process (reversing step). As a result, the straight pipe portion 8a after bending moves to the left (opposite to the bending direction). After this movement, the clamp body 2 is positioned on the rear side of the rail 51.

  Then, after holding the metal tube 10 with the clamp body 2 and the clamp portion 32 of the bending arm 3 sandwiching the next bending portion, the bending portion is heated by the heating body 41. This heating is performed in the same manner as the above-described heating. While heating the bent portion, the clamp body 2 is advanced to bend the metal tube 10 to the right side, and the metal tube 10 is bent as described above. A plurality of straight pipe portions are formed from one straight metal pipe 10 by repeatedly performing the bent pipe portion forming step (first bent pipe portion forming step, second bent pipe portion forming step) and the reversing step. It is possible to form a meandering tube 8 having a self-fluxing alloy film 9 at a desired location on the outer surface, for example, a meandering tube 8 as shown in FIG. Manufacturing method of meandering tube).

  In this way, when the single straight metal tube 10 is formed in the meandering tube 8, even when there are a plurality of bent tube portions 8b, the bending direction is always the same in a plurality of bending processes, and the right side of the metal tube 10 On the right side, there are moving means 6 for moving the clamp body 2 (one ball screw 61 and bearings 63 and 64 for supporting the ball screw 61 (including a cover for covering the bearing), a driven pulley 65 ( Including the cover that covers the driven pulley))) is not installed. For this reason, when the metal pipe 10 is bent by a 180 ° bend with a small radius, for example, R95 (diameter 95 cm), the moving means 6 becomes an obstacle even if the length of the straight pipe portion 8a after the bending is long. Without bending, the metal tube 10 can be bent. That is, since the moving means 6 is disposed below the straight pipe portion 8a and in a region on the left side of the straight pipe portion 8a (region opposite to the bending direction), the moving means 6 has a small radius of 180. ° Does not interfere with bending. As a result, a meandering tube 8 having a plurality of straight tube portions 8a and bent tube portions 8b bent from a single straight metal tube 10 with a small radius and having a self-fluxing alloy film 9 formed thereon can be formed. it can.

  One ball screw 61 that is a moving member that moves the clamp body 2 has a shorter distance in the horizontal direction and a distance in the height direction between the axis of the metal tube 10 held by the clamp body 2 and the axis of the ball screw 61. Thus, it is preferable to dispose the metal tube 10 close to the metal tube 10, so that the bending moment acting on the metal tube 10 when the metal tube 10 is advanced can be reduced. In addition, when the metal tube 10 is gripped by the clamp body 2 or the clamp portion 32, when the portion that directly grips the metal tube 10 is formed by the aluminum clamp members 27 and 29, when the metal tube 10 is gripped, It is possible to prevent cracking of the metal tube 10, cracking of the metal powder layer or self-fluxing alloy film, and peeling.

  The guide portion 7 is provided on the second fixed base 14, and the metal tube 10 is guided to the heating body 41 by the guide portion 7, so that the metal tube 10 can be advanced in the axial direction without being displaced. At this time, when the guide portion 7 is formed by a pair of left and right guide rollers 71 and 72 and one of the pair of left and right guide rollers 71 and 72, for example, the right guide roller 72 is formed to be movable to the left and right by the handle 73, Even if the diameter of the metal tube 10 is different, the metal tube 10 can be guided in the axial direction.

  A rotary shaft support portion 15 that rotatably supports the rotary shaft 30 of the bending arm 3 is attached to the second fixed base 14 so that the position of the bending arm 3 can be adjusted in the left-right direction, and the arm portion 31 of the bending arm 3 is horizontal to the clamp portion 32. Since the direction position is adjustable, the position of the rotating shaft 30 can be adjusted to the left and right with respect to the metal tube 10. Thereby, the radius at the time of bending the metal tube 10 can be arbitrarily adjusted. Moreover, since the arm part 31 of the bending arm 3 is formed so that the horizontal position and the height direction position of the clamp part 32 can be adjusted, the position of the clamp part 32 that holds the metal tube 10 can be vertically and horizontally. Can move. As a result, even if the diameter of the metal tube 10 is different, the position of the clamp part 32 that holds the metal tube 10 can be adjusted to an optimum position.

  Moreover, you may make it form the self-fluxing alloy film 9 of the part used as the straight pipe part 8a after a bending process with the bending apparatus 1 of the metal pipe of this embodiment. In this case, as one straight metal tube 10, for example, a metal powder layer containing a self-fluxing alloy that is heated and remelted is formed in a portion that becomes the straight tube portion 8a after bending, and bending processing is performed. A metal tube formed at a portion where the portion has a metal powder layer and a portion which does not have a metal powder layer is used.

  First, the heat remelting process of the metal powder layer from the front-end | tip of the metal pipe 10 to a bending process location is performed. The metal tube 10 is placed on the lower clamp member 22 of the clamp body 2 through the upper and lower clamp members 21 and 22 of the clamp body 2, the guide rollers 71 and 72, and the heating body 41 sequentially from the tip. After mounting, the metal tube 10 is held by the upper and lower clamp members 21 and 22 of the clamp body 2, and the end portion where the metal powder layer of the metal tube 10 is formed by the heating body 41 is annularly heated and melted. The clamp body 2 is advanced while being heated to a possible temperature. As a result, the metal powder layer is heated and remelted while the metal tube 10 advances forward, and the self-fluxing alloy film 9 is formed. As a result, the self-fluxing alloy film 9 is formed on the metal pipe 10 that becomes the straight pipe portion 8a up to the bending portion (straight pipe portion forming step).

  Next, the holding of the metal tube 10 by the clamp body 2 is released, and the clamp body 2 is moved to the rear side of the rail 51. After the movement, the clamp body 32 and the clamp portion 32 of the bending arm 3 hold the metal tube 10 while sandwiching the bending portion, and the heating portion 41 heats the bending portion. This heating is performed at a different temperature depending on the presence or absence of the metal powder layer as in the above-described heating. While heating the bent portion, the clamp body 2 is advanced to bend the metal tube 10 to the right side, and the metal tube 10 is bent as described above. As a result, a bent tube portion 11c bent by 180 ° is formed on the metal tube 10, and a self-fluxing alloy film 9 is formed when the bent portion has a metal powder layer (curved tube). Part forming step). This completes the bending of one bent pipe portion 8b.

  After the formation of one bent pipe portion 8b, the heat remelting process of the metal powder layer of the metal tube 10 up to the next bending portion is performed in the same manner as the heat remelting process of the metal powder layer (straight pipe part forming step). ). Thereby, the self-fluxing alloy film 9 is formed on the outer surface of the metal tube 10 which becomes the straight tube portion 8a up to the next bending portion.

  Then, after the gripping by the clamp body 2 is released and the metal tube 10 is rotated by 180 ° around the axis of the straight metal tube 10 before bending, the clamp body 2 and the bending arm are rotated. 3, the metal tube 10 is held in a state where the bent portion is sandwiched, and then the clamp body 2 is advanced while the bent portion is heated by the heating body 41 in the same manner as described above. Apply bending. Thereby, as for the metal pipe 10, two straight pipe parts 11b and two curved pipe parts 11c are formed continuously from the front end. Therefore, by repeating these straight pipe part forming process, curved pipe part forming process, and reversing process, a single straight metal pipe 10 has a plurality of straight pipe parts 8a and curved pipe parts 8b and an outer surface. The serpentine tube 8 having the self-fluxing alloy film 9 at the desired location, for example, the serpentine tube 8 as shown in FIG. 4 can be formed (second method for manufacturing a serpentine tube).

  Moreover, although the bending apparatus 1 of the metal tube of this embodiment demonstrated the case where the meandering tube 8 was formed from the metal tube 10 in which the metal powder layer was formed in the desired location of an outer surface, it is not limited to this. For example, a serpentine tube is formed only by bending, a serpentine tube is formed from a metal tube having a metal powder layer formed entirely, or a self-fluxing alloy is formed in a portion that becomes a straight tube portion after bending A meandering tube can be formed from a metal tube in which a film is formed and a metal powder layer is formed at a bending portion.

  When forming a meandering tube by performing only bending, the bent tube is formed in the same manner as described above, except that the metal tube 10 is heated by the heating element 41 at a temperature at which the metal tube 10 can be plastically deformed. By repeating the step (second bent tube portion forming step) and the inversion step, a meandering tube having a plurality of straight tube portions 8a and bent tube portions 8b can be formed from one straight metal tube 10. .

  When forming a meandering tube from a metal tube having a metal powder layer formed entirely, it is substantially the same as the method for manufacturing the second meandering tube described above, that is, when bending is performed, the metal by the heating element 41 is used. A curved pipe part forming step (first curved pipe part forming step) is performed in the same manner as described above except that the pipe 10 is heated at a temperature at which the metal pipe 10 can be plastically deformed and the metal powder layer can be heated and remelted. By repeating the straight pipe portion forming step and the reversing step, a meandering pipe having a plurality of straight pipe portions 8a and a curved pipe portion 8b and having a self-fluxing alloy film 9 is formed from one straight metal pipe 10. can do.

  In the case where a meandering tube is formed from a metal tube in which a self-fluxing alloy film is formed on a portion that becomes a straight tube portion after bending and a metal powder layer is formed at a bending portion, In substantially the same manner as the meander tube manufacturing method, that is, when bending is performed, the metal tube 10 is heated by the heating body 41 at a temperature at which the metal tube 10 can be plastically deformed and the metal powder layer can be heated and remelted. A plurality of straight pipe sections 8a and curved pipes are formed from one straight metal pipe 10 by repeatedly performing a bent pipe section forming process (first bent pipe section forming process) and a reversing process which are performed in the same manner as described above. A meandering tube having the portion 8b and the self-fluxing alloy film 9 can be formed.

DESCRIPTION OF SYMBOLS 1 Metal pipe bending apparatus 2 Clamp body 3 Bending arm 4 Heating means 5 Support means 6 Moving means 7 Guide part 8 Meandering pipe 8a Straight pipe part 8b Curved pipe part 9 Self-fluxing alloy film 10 Metal pipe 30 Rotating shaft 61 Ball screw

Claims (4)

A clamp body for gripping a straight metal tube;
It is ahead of the gripping part of the clamp body and in front of the bending part of the metal tube, and is arranged on one side with respect to the metal tube , and the upper end turns around a rotation axis lower than the metal tube. Possible bending arms,
Heating means for heating the bending portion;
A support means provided below the metal tube to support the clamp body so as to be movable in the axial direction of the metal tube;
Below the metal tube, a moving means by a ball screw arranged in a region on the side opposite to the rotation axis with respect to the metal tube to move the clamp body , the ball screw being in the region Moving means positioned below the metal tube and disposed in proximity to the metal tube at a position that does not interfere with the support means of the clamp body ,
By advancing the clamping member while heating the bending point of the metal tube is gripped by the bending arm and the clamping member, the rotation by the action of bending moment to said bent portion with pivoting the bending arm An apparatus for bending a metal tube, wherein the metal tube is bent and deformed around an axis. Said clamp member and said bending arm, the bending apparatus for metal tubes according to claim 1, portions for gripping the metal tube is formed by the clamp member made of aluminum. When manufacturing a non-connected meandering pipe having a plurality of straight pipe parts and curved pipe parts from one straight metal pipe using the metal pipe bending apparatus according to claim 1 or 2 ,
A bent tube portion forming step of bending the metal tube by 180 ° while advancing the metal tube while heating the bent portion of the metal tube to a temperature capable of plastic deformation of the metal tube;
Before forming the next bent pipe part after forming one bent pipe part, comprising a reversing step of rotating the metal pipe forward and rotating it 180 ° around the axis to invert the bent pipe part, And a method of manufacturing a meandering tube in which the metal tube is meandered by repeatedly performing a reversing step ,
The one straight metal pipe has a self-fluxing alloy film formed on a portion that becomes a straight pipe part after bending, and a metal powder containing a self-fluxing alloy in which the bending part is heated and remelted A metal tube formed in a portion having a layer and a portion not having the metal powder layer,
In the bent tube portion forming step, the metal tube is bent 180 ° while being heated at a temperature where the metal powder layer can be plastically deformed and the metal powder layer can be heated and remelted at the bending portion. A first bent tube portion forming step, and a second bent tube portion forming step of bending the metal tube by 180 ° while heating to a temperature at which the metal tube can be plastically deformed at a bending portion where the metal powder layer is not provided. A method for manufacturing a meandering tube. The straight metal pipe according to claim 3 is formed with a metal powder layer containing a self-fluxing alloy that is heated and remelted in a portion that becomes a straight pipe portion after bending, and the bending portion when There is a metal tube formed into a portion without the part and the metal powder layer having the metal powder layer,
While the part that becomes the straight pipe part after the bending process having the metal powder layer is heated at a temperature at which the metal powder layer can be heated and remelted, the metal pipe is advanced, and the part that becomes the straight pipe part is a self-fluxing alloy. The method for manufacturing a meandering pipe according to claim 3, further comprising a straight pipe part forming step of forming a film.

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