JP2014065072A - Processing device for bending metal tube and method of manufacturing metal tube with bent part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a small-sized and simple processing device for compression-bending.SOLUTION: A processing device comprises heating means for heating a metal tube, propulsion means for propelling the metal tube, and a clamp arm which grips the metal tube and is rotatable around a spindle part. Further, the processing device is equipped with guide means which revolves the point of the metal tube gripped by the clamp arm around the spindle part with propulsion of the metal tube and applies bending moment to the metal tube, and a bearing for rotatably supporting the clamp arm at the spindle part. The bearing comprises one or more bearings with brake means each of which includes an inner ring and an outer ring which are coaxially disposed, a support body which is interposed between the inner ring and the outer ring in such a manner that the inner ring and the outer ring can rotate relatively to each other, and brake means which contacts the inner ring or the outer ring and suppresses the relative rotation of the inner ring and the outer ring by frictional force. The brake means suppresses rotation of the clamp arm during the process of bending the metal tube, whereby compressive force is applied to the metal tube.

Description

  The present invention relates to a metal pipe bending apparatus and a method of manufacturing a metal pipe having a bent pipe portion, and more particularly to a technique of bending a metal pipe while preventing a decrease in the tube thickness on the outer periphery of the bending.

  Today, metal pipes are widely used as pipes for transporting fluids such as oil, gas, and various liquids in industrial facilities such as plants, factories, and power plants, or as skeleton structures for buildings such as bridges and stadium roofs. These metal pipes are pipes that have been standardized and manufactured in advance to a predetermined shape (straight pipes, elbows, bends, etc.), while straight pipes are bent according to the construction object. (Hereinafter referred to as “bend pipe”) is widely used because it can flexibly cope with various curvatures and pipe shapes.

  On the other hand, when a bent pipe is manufactured, simply bending a straight pipe as a raw material may reduce the thickness of the outer peripheral side of the bent pipe portion and may not satisfy the strength required for the pipe. Therefore, bending (so-called compression bending) is performed to prevent such reduction (thinning) of the tube thickness by applying a compressive force in the tube axis direction simultaneously with bending.

  FIGS. 13 to 14 are views showing an apparatus capable of such compression bending (an apparatus similar to Patent Document 1 described later). As shown in this figure, the apparatus is a metal tube 11 to be processed. An induction heating coil 12 that heats a part of the coil 12 annularly, a clamp arm 13 that grips the metal tube 11 at a position closest to the front side of the coil 12, and a support shaft that rotatably supports the clamp arm 13 with respect to the apparatus frame 16 A portion 61, a propulsion unit 17 that pushes the metal tube 11 forward, and a guide roller 20 that guides the traveling metal tube 11 to pass through the coil 12 are provided.

  The propulsion unit 17 includes a rear clamp 18 that holds the rear end of the metal tube 11 and a hydraulic cylinder 19 that pushes the metal tube 11 forward toward the coil 12, and the clamp arm 13 is orthogonal to the metal tube 11. The arm main body 15 extends horizontally in the left-right direction, and the clamp portion 14 provided in the arm main body 15 so that the metal tube 11 can be gripped at a position in front of the coil 12.

  Further, the support shaft portion 61 is installed so as to be able to stand on the device frame 16 so as to rise vertically upward from the device frame 16 and to be able to rotate on the center shaft portion 62 through the bearing 26. It has a cylindrical support shaft main body 63, and the support shaft main body 63 supports the proximal end portion of the clamp arm 13 in a cantilever shape. Further, a large gear 71 that rotates together with the support shaft main body 63 (and thus with the clamp arm 13) is fixed to the support shaft main body 63, and a small gear 72 that meshes with the large gear 71, and the small gear 72 are connected. And a hydraulic motor 73 that applies a rotational force in the reverse direction to the clamp arm 13. In addition, the point shown with the code | symbol C in FIG. 13 shows the rotation center of the clamp arm 13 (support shaft main-body part 63).

  In processing, while holding the front portion of the heating portion of the metal tube 11 by the induction heating coil 12 by the clamp arm 13, the gripping point is turned around the support shaft 61 as the metal tube 11 is advanced by the propulsion unit 17. Thereby, a bending moment is applied to the metal tube 11. At the same time, by using the hydraulic motor 73, a compressive force is applied to the metal tube 11 by applying a rotational force in the direction opposite to the rotational direction of the clamp arm 13 to the clamp arm 13 via the large gear 71. .

  Moreover, there exist the following patent documents 1-2 as a proposal relevant to such compression bending. Further, Patent Document 3 below relates to a bearing having a function of stopping rotation.

Japanese Patent Publication No. 51-10835 JP 2009-12062 A Japanese Patent No. 4635466

  By the way, in the conventional processing apparatus that performs compression bending (Patent Document 1), a compression mechanism such as a large gear or a hydraulic motor must be provided around the support shaft in order to apply a compression force to the metal pipe. There is a difficulty that the apparatus becomes complicated and large-scale. Also, the apparatus of Patent Document 2 has a problem that a guide wheel (pinion) and a rack having a large diameter must be provided around the support shaft, as in the apparatus of Patent Document 1.

  In particular, when a thinning rate is required to be zero or close to zero, a large compressive force of, for example, several tons or more is applied to the metal tube during machining, depending on the pipe diameter and the like. It is necessary to increase the diameter of the large gear, and it is necessary to use a hydraulic motor and a hydraulic circuit corresponding to a large output.

  Thus, in a processing apparatus that performs compression bending, conventionally, the entire apparatus becomes large, and the processing apparatus becomes expensive. Therefore, it is necessary to increase the manufacturing cost of a bending pipe that performs processing using this apparatus. Absent. Moreover, since the processing apparatus is large, a large installation space and work space are also required.

  The invention described in Patent Document 3 is not related to bending of a metal tube, but relates to a bearing that stops a bucket provided in a construction machine such as a hydraulic excavator and maintains the stopped state. It is not intended to suppress rotation (brake while allowing rotation) as in the present invention described later.

  Therefore, an object of the present invention is to solve the problems in the compression bending process as described above. By simplifying the mechanism for applying the compression force, a compression bending apparatus that is smaller and simpler than conventional ones is realized, It is in the point which reduces the processing cost of the compression bending of a metal pipe.

  In order to solve the above-mentioned problems and achieve the object, a metal pipe bending apparatus according to the present invention comprises a heating means for heating a part of a metal pipe to be bent in an annular shape, and a metal pipe facing the heating means. A propulsion means for propelling in the direction of the tube axis; and a clamp arm that grips the metal tube and is rotatable about the support shaft. The clamp arm grips a front portion of the heating portion of the metal tube by the heating means. The gripping point is swiveled around the support shaft portion as the metal tube is propelled by the propulsion means, whereby a guide means for applying a bending moment to the metal tube, and the clamp arm is rotatably supported at the support shaft portion. The inner ring and the outer ring arranged coaxially, and between the inner ring and the outer ring so that the inner ring and the outer ring can rotate relative to each other. Including one or more bearings with brakes, each of which includes a support member and a brake means that abuts against the inner ring or the outer ring and suppresses relative rotation between the inner ring and the outer ring by a frictional force. By suppressing the rotation of the clamp arm by the brake means during processing, a compression force can be applied to the metal pipe.

  In the bending apparatus of the present invention, similarly to the conventional processing apparatus, the metal pipe is propelled while the metal pipe is heated in an annular shape by the heating means, and at the same time, the metal pipe that has passed the heating means by the clamp arm is provided. Guide an arc to curve. Specifically, when the propulsion direction of the metal tube is “front” (in this application, the front side is described as “front” and the reverse direction is “rear” in the reverse direction), heating is performed. The front part of the part is gripped by the clamp arm. The clamp arm is installed so as to be rotatable around the support shaft, and rotates as the metal tube is propelled by the propulsion means, so that the gripping portion turns around the support shaft. As a result, a bending moment is applied to the heated portion of the metal tube, thereby causing the metal tube to be continuously plastically deformed and bent so as to draw an arc.

  On the other hand, by applying a compressive force in the direction of the pipe axis in addition to the bending moment, thinning of the pipe outer peripheral side (thickness reduction) is prevented. This compression force is generated in the apparatus of the present invention by suppressing the rotation of the clamp arm by the brake means of the bearing with brake unlike the conventional apparatus.

  Specifically, in this apparatus, a clamp arm that holds a metal tube is rotatably installed via a bearing with a brake provided on a support shaft portion. The bearing with brake includes an inner ring and an outer ring that are coaxially arranged so as to be relatively rotatable via a support, and a brake unit that abuts against the inner ring or the outer ring and suppresses the relative rotation between the inner ring and the outer ring by a frictional force. The brake means is used to brake the rotation of the clamp arm during bending. At this time, since the propelling force by the propelling means is applied to the metal tube, the compressive force in the tube axis direction acts on the metal tube, thereby reducing the amount of thinning during bending.

  The support interposed between the inner ring and the outer ring in the brake bearing is typically a rolling element (ball or roller), and the bearing is typically a ball bearing or roller bearing. . However, the said support body does not exclude support bodies (for example, liquid, gas, etc.) other than a rolling element, and this invention is not a ball bearing and a roller bearing as a bearing (bearing with a brake and a bearing without a brake function). This does not exclude the use of other bearings (such as fluid bearings).

  According to the device structure of the present invention, there is no need to provide a mechanism for applying a compressive force to the metal pipe outside the bearing, and the large gear, the small gear, the hydraulic motor, etc., conventionally provided around the support shaft can be omitted. Therefore, the apparatus structure can be simplified and downsized. Note that the phrase “contacting the inner ring or the outer ring” for the brake means is not limited to a structure that directly contacts the inner ring or the outer ring, but indirectly contacting the inner ring or the outer ring, in other words, the inner ring or the outer ring. It also includes a structure for braking the rotation of the inner ring or the outer ring by contacting another member that is fixed and rotates together with the inner ring or the outer ring. Further, the “other member” is a member formed separately from the inner ring or the outer ring, and may be connected to the inner ring or the outer ring, or may be formed integrally with the inner ring or the outer ring.

  Further, the present invention uses only the above-mentioned bearing with a brake as a bearing for supporting the clamp arm in the support shaft, and does not prohibit the use of a normal bearing without a brake function. Of course, a bearing with a brake and a normal bearing without a brake function may be used in combination.

  Moreover, in one aspect of the present invention, two or more of the bearings are provided, and two or more of these bearings are the bearings with a brake. If a plurality of bearings with brakes are provided in this way, a large braking force can be generated to apply a large compressive force to the metal pipe. In the present invention, for example, there may be only one bearing that supports the clamp arm as in a third embodiment described later. In this case, the one bearing is a bearing with a brake.

  Furthermore, in compression bending, the generation of a tipping moment (a force that tilts the support shaft and the clamp arm) that causes twisting of the bending pipe (metal pipe to be processed) has been a problem in the past. However, in the present invention, the clamp arm is not rotated by applying an external force that reversely rotates the clamp arm and pulls back the metal tube as in conventional compression bending, but brakes the rotation of the clamp arm. Therefore, no force that is perpendicular to the rotation axis of the clamp arm that causes the overturning moment is generated by applying the braking force. Therefore, according to the present invention, the problem of the overturning moment as described above can be reduced.

  In addition, when an external force for compression is applied as in the prior art (particularly when the support point of the rotation axis of the clamp arm and the application point of the external force are shifted), the bending moment due to the external force is applied to the clamp arm. Although it will be applied to the shaft part (rotating shaft), according to the present invention, since such an external force is not applied, the supporting shaft part (rotating shaft) of the clamp arm can be made thinner than before. Therefore, the present invention is advantageous in realizing a compact and simple compression bending apparatus.

  In the present invention, the position of the bearing with a brake is not particularly limited as long as it can brake the rotation of the clamp arm. Therefore, in the present invention, the brake bearing can be provided at any position on the rotation axis of the clamp arm (the same applies to the manufacturing method described later).

  Further, in another aspect of the present invention, the brake means is connected to the outer ring and a plurality of plate-shaped ring members arranged so as to be connected to the inner ring and stacked in the rotation axis direction of the bearing. A plurality of plate-like ring members arranged so as to be stacked in the direction of the rotation axis of the bearing, and the ring member connected to the inner ring and the ring member connected to the outer ring are alternately The ring member connected to the inner ring and the ring member connected to the outer ring rotate relative to each other as the inner ring and the outer ring rotate relative to each other, and the brake means includes the inner ring And a pressing member that presses the ring member connected to the outer ring and the ring member connected to the outer ring together to suppress relative rotation between the ring members.

  If the above-mentioned bearing is used as the bearing with a brake, a strong braking force, that is, a large compressive force can be applied to the metal pipe, and the thinning rate of the object to be processed is suppressed, for example, the thickness reduction rate is zero. It is possible to meet strict specification requirements close to zero. For the ring member, “connecting” to the inner ring or the outer ring does not mean that the ring member is formed separately from the inner ring or the outer ring and connected to the inner ring or the outer ring by a method such as welding. Rather, it includes a structure in which the ring member is formed integrally with the inner ring and the outer ring.

  Moreover, the manufacturing method of the metal pipe provided with the curved pipe part according to the present invention includes a step of heating a part of the metal pipe to be bent in an annular shape by a heating means, and a front side of the heating part of the metal pipe. A step of applying a bending moment to the metal tube by propelling the metal tube in the tube axis direction toward the heating means while grasping a nearby position by a clamp arm rotatable around the support shaft. In the method of manufacturing a pipe, the clamp arm is rotatably supported via a bearing at the support shaft portion, and the bearing has an inner ring and an outer ring arranged coaxially, and the inner ring and the outer ring rotate relative to each other. A support body interposed between the inner ring and the outer ring so that the inner ring and the outer ring can be supported, and a brake means that abuts against the inner ring or the outer ring and suppresses relative rotation between the inner ring and the outer ring by a frictional force. And the manufacturing method suppresses the rotation of the clamp arm by suppressing the relative rotation of the inner ring and the outer ring by the brake means during the step of applying a bending moment to the metal pipe. Thus, a compressive force is applied to the metal tube.

  Also, the manufacturing method may include a plurality of brake bearings for the same reason as the processing apparatus according to the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the mechanism which provides compressive force can be simplified, a small and simple compression bending apparatus can be implement | achieved, and it becomes possible to reduce the cost of the compression bending process of a metal pipe.

  Other objects, features, and advantages of the present invention will become apparent from the following description of embodiments of the present invention described with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the claims. Moreover, in each figure, the same code | symbol shows the same or an equivalent part.

FIG. 1 is a plan view showing a metal tube bending apparatus according to the first embodiment of the present invention (a heating coil, a clamp part, a support frame part, etc. are appropriately cut out). FIG. 2 is a front view showing the metal tube bending apparatus according to the first embodiment (rotating shaft portion and ball bearing are appropriately cut out / the same applies to FIGS. 3 to 4). FIG. 3 is a front view showing a metal pipe bending apparatus according to the second embodiment of the present invention. FIG. 4 is a front view showing a metal pipe bending apparatus according to the third embodiment of the present invention. FIG. 5 is a cross-sectional view showing a brake bearing that can be used in the first to third embodiments. FIG. 6 is an enlarged view of a part of FIG. 5 (part G). FIG. 7 is a horizontal cross-sectional view (cross-sectional view taken along the line FF in FIG. 5) of the bearing with brake. FIG. 8 is a view showing another example of the bearing with brake as in FIG. FIG. 9 is a view showing still another example of the bearing with brake as in FIG. FIG. 10 is a view showing still another example of the bearing with brake as in FIG. FIG. 11 is a view showing still another example of the bearing with brake as in FIG. FIG. 12 is a view showing still another example of the bearing with brake as in FIG. FIG. 13 is a plan view showing a conventional processing apparatus capable of compression bending. FIG. 14 is a front view showing the conventional processing apparatus.

[First Embodiment]
As shown in FIGS. 1 to 2, the bending apparatus according to the first embodiment of the present invention is an induction heating coil (hereinafter simply referred to as “coil”) that heats a metal pipe 11 to be processed in an annular shape. 12), a clamp arm (hereinafter simply referred to as “arm”) 13 that holds the metal tube 11 at a position in front of the coil 12, and a support that rotatably supports the clamp arm 13 with respect to the apparatus frame 16. A shaft portion 21, a propulsion portion 17 that pushes the metal tube 11 forward, and a guide roller 20 that guides the traveling metal tube 11 to pass through the coil 12 are provided.

  The propulsion unit 17 includes a rear clamp 18 that holds the rear end of the metal tube 11 and a hydraulic cylinder 19 that pushes the metal tube 11 forward toward the coil 12. In addition, the clamp arm 13 is provided in the arm main body 15 so as to be able to grip the metal tube 11 at the front position of the coil 12 and the arm main body 15 extending horizontally in the left-right direction orthogonal to the metal tube in the initial state at the start of processing. And a clamp portion 14.

  The support shaft portion 21 has a cylindrical rotation shaft portion 22 that supports the base end portion of the clamp arm 13 in a cantilever shape, and a support that rotatably supports the rotation shaft portion 22 via ball bearings 25 and 26. The shaft frame portion 23, and the support shaft portion 22 and the support shaft frame portion 23 are supported on the device frame 16 so as to be movable along the device frame 16 in the left-right direction (direction perpendicular to the propulsion direction of the metal tube 11). A shaft foot 24 is provided. In addition, the point shown with the code | symbol C in FIG. 1 has shown the rotation center of the clamp arm 13 (rotating shaft part 22).

  The rotating shaft portion 22 is rotatably supported on the support shaft frame portion 23 via the ball bearings 25 and 26 provided at the upper end portion and the lower end portion as described above, but the bearing 25 at the upper end portion is rotated. This is a ball bearing with a brake provided with a brake ring (not shown in FIGS. 2 to 4 to be described later) for applying braking. In the apparatus of the present embodiment, the bearing 25 with a brake causes the metal tube 11 to be bent during bending. On the other hand, compressive force is applied. The bearing 26 at the lower end is a normal ball bearing that does not include such a brake ring.

  Contrary to the above, the bearing configuration may be such that the lower bearing 26 is a brake bearing and the upper bearing 25 is a normal bearing, or both the upper and lower bearings 25 and 26 are brake bearings. It is also possible.

  The support shaft portion 21 can be moved along the device frame 16 and the clamp portion 14 can be moved along the clamp arm 13 in the left-right direction (direction perpendicular to the propulsion direction of the metal tube 11). Yes (see arrow D and arrow E), the bending radius of the metal tube 11 can be changed by adjusting the positions of the support shaft portion 21 and the clamp portion 14 in the left-right direction. For example, when it is desired to reduce the bending radius, the clamp portion 14 is shifted in the direction approaching the support shaft portion 21 (leftward in FIG. 2), and the support shaft portion 21 is moved toward the tip end of the clamp arm 13 (rightward in FIG. 2). ) If you want to increase the bend radius, you can do the reverse operation.

  As shown in FIGS. 5 to 7, the brake bearing 25 includes an inner ring 31 and an outer ring 32 that are coaxially arranged, and these inner ring 31 and outer ring 32. Are provided with rolling elements (balls) 33 interposed between the inner ring 31 and the outer ring 32 so that they can rotate relative to each other. However, unlike ordinary ball bearings, the surface of the inner ring 31 (in FIGS. 5 to 6). And a brake ring 34 that abuts against the upper surface and suppresses relative rotation between the inner ring 31 and the outer ring 32.

  As shown in FIG. 7 which is a FF cross section of FIG. 5, the brake ring 34 is annular. The brake ring 34 is incorporated in the inner peripheral side edge of the outer ring 32 so as to be accommodated in an annular groove (annular groove) 35 formed on the bottom surface of the outer ring 32 (surface facing the inner ring 31). It moves like a piston in a direction perpendicular to the rotation surfaces of the inner ring 31 and the outer ring 32, that is, in a direction parallel to the rotation axis of the inner ring 31 and the outer ring 32 (the vertical direction in FIGS. 5 to 6). The surface abuts against the inner ring 31 to generate a frictional force, thereby suppressing relative rotation between the inner ring 31 and the outer ring 32.

  Further, in order to fix the brake ring 34 in the circumferential direction, that is, to prevent the brake ring 34 abutting against the inner ring 31 from rotating idle (relatively rotating with respect to the outer ring 32), A plurality of convex engaging portions 37 are formed along the circumferential direction, and a plurality of concave engaging portions 38 that are fitted to the engaging portions 37 are formed along the circumferential direction on the brake ring 34. Reference numeral 36 in the figure denotes an oil supply hole for supplying hydraulic oil for operating the brake ring 34, and reference numeral S denotes a sealing material for sealing the hydraulic oil for the brake ring 34, the lubricating oil for the ball 33, and the like. Reference numeral 40 denotes a bolt hole for mounting the bearing 25 (the same applies to the drawings described later).

  The bearing 25 with brake does not include means for positively retracting the brake ring 34 in a direction away from the inner ring 31 when the brake ring 34 is not used (not braked), but such means is provided. It is also possible. As the means, for example, a spring for urging the brake ring 34 in the backward direction may be provided, or the brake ring 34 may be retracted by hydraulic pressure.

  Further, as shown in FIG. 8, if a brake pad 39 made of a friction material is provided on one or both of the surface facing the inner ring 31 of the brake ring 34 and the surface facing the brake ring 34 of the inner ring 31, the braking force (Thus, the compressive force applied to the metal tube) can be increased.

  Further, in the brake ring 34, the outer ring 32 is provided with the brake ring 34 and is brought into contact with the inner ring 31, but for example, as shown in FIG. It is also possible to adopt a structure in which this abuts against 32.

  Further, in the bearing structure, the brake ring 34 is directly brought into contact with the inner ring 31. However, as described above, a structure in which the brake ring 34 is indirectly brought into contact with the inner ring 31 (or the outer ring 32) may be employed. is there. Specifically, for example, as shown in FIG. 10, a flange portion 41 can be formed on the inner ring 31 so as to extend from the inner ring 31 in the outer circumferential direction, and the brake ring 34 can be brought into contact with the flange portion 41. .

  Two or more brake rings 34 may be provided. For example, as shown in FIG. 11, if a first brake ring 34 that directly contacts the main body portion of the inner ring 31 and a second brake ring 34 that contacts a flange portion 41 formed on the inner ring 31 are provided, it is more powerful. Can obtain a good braking force.

  Further, as the bearing with brake, one having a structure as shown in FIG. 12 may be used.

  Specifically, as shown in FIG. 12, the bearing with brake includes a plurality of plate-shaped ring members 51 connected to the inner ring 31 and stacked in the direction of the rotation axis of the bearing, and the outer ring. A plurality of plate-like ring members 52 connected to each other and arranged so as to be laminated in the rotation axis direction of the bearing, and a ring member 51 connected to the inner ring 31 and a ring member 52 connected to the outer ring 32; The ring member 51 connected to the inner ring 31 and the ring member 52 connected to the outer ring 32 are rotated relative to each other with relative rotation of the inner ring 31 and the outer ring 32.

  The bearing with a brake has a brake ring 34 that moves in parallel to the rotation axis of the bearing, similar to the brake ring shown in FIG. 5 and the like. The brake ring 34 is connected to the ring member via a brake pad 39. 51, the ring member 51 on the inner ring 31 side and the ring member 52 on the outer ring 32 side are brought into pressure contact with each other, and the relative rotation of the ring members 51 and 52 is caused by the frictional force between the ring members 51 and 52. In this way, the relative rotation between the inner ring 31 and the outer ring 32 is braked.

  According to such a bearing with a brake, it is possible to obtain a large braking force as compared with the bearing structure in which the brake ring 34 is simply brought into contact with the inner ring 31 or the outer ring 32 to perform braking, and a large compressive force is applied to the metal pipe. Can be given.

[Second Embodiment]
A processing apparatus according to the second embodiment of the present invention will be described.
The device of this embodiment includes an induction heating coil, a clamp arm, a device frame, a support shaft portion, a propulsion portion, and the like, similar to the device of the first embodiment, and the device of the first embodiment. Differently, as shown in FIG. 3, a plurality (three in this example) of ball bearings with brakes 25a, 25b, and 25c are provided as ball bearings for supporting the upper end portion of the rotating shaft portion 22. The brake bearings 25a, 25b, and 25c are not limited to three, and may be two, or four or more.

  According to the device structure of this embodiment, a stronger braking force (compression force to the metal tube) than that of the device of the first embodiment can be obtained. Further, in addition to increasing the number of bearings with brakes as in this embodiment, the bearing structure (FIG. 8) including the brake pad 39 having a large friction described above and two or more brake rings 34 are provided. If one or more of the bearing structure (FIG. 11) or the structure (FIG. 12) provided with multiple ring members 51 and 52 for braking are appropriately combined, a stronger braking force can be obtained.

[Third Embodiment]
A processing apparatus according to the third embodiment of the present invention will be described.
The device of this embodiment includes an induction heating coil, a clamp arm, a device frame, a support shaft portion, a propulsion portion, and the like, as with the device of the first embodiment, and has a brake as with the device of the second embodiment. Unlike the apparatus of the first and second embodiments, the arm 13 is directly fixed to the bearing 25d with a brake as shown in FIG. The bearing with brake 25d has a larger diameter than the bearings in the devices of the first and second embodiments, and the base end portion of the arm 13 is installed on the upper surface of the inner ring 31 that rotates like a turntable.

  According to this embodiment, the rotating shaft portion 22 and the support shaft frame portion 23 provided in the first and second embodiments are not necessary, and only one bearing is required to support the arm 13 (bearing with brake). 25d only), the number of parts can be reduced, and the device structure and maintenance can be simplified.

  The operation at the time of compression bending by the apparatus of each embodiment will be described as follows.

  The tip of the metal tube 11 to be processed is gripped by the clamp portion 14, and the metal tube 11 is pushed forward toward the coil 12 by the propulsion unit 17 (see arrow A in FIG. 1). With this propulsion, the clamp arm 13 rotates (see arrow B in FIG. 1), and a bending moment is applied to the metal tube 11. Due to this bending moment, the heated portion of the coil 12 of the metal tube 11 is continuously plastically deformed (see the two-dot chain line in FIG. 1). At the same time, the brake ring 34 of the bearing 25 with brake (25a to 25d) is operated to brake the rotation of the clamp arm 13. By this braking, a compressive force is generated in the metal tube 11 in the tube axis direction, thereby suppressing the thinning of the metal tube 11 on the bending outer peripheral side.

  In order to reduce the thickness reduction rate, the compression force, that is, the braking force by the brake bearings 25 (25a to 25d) may be increased. The adjustment of the braking force is, for example, an apparatus for increasing the oil supply pressure of the brake bearings 25 (25a to 25d) to the brake ring 34 and a plurality of brake bearings (for example, the second embodiment). In this case, it is possible to adjust the number of bearings 25a to 25d for operating the brake ring 34 by one or both of them.

  The advantages of the apparatus of each of the embodiments will be summarized as follows.

(1) It is not necessary to provide a mechanism for generating a compression force such as the large gear 71 and the hydraulic motor 73 at the lower end of the support shaft portion 61 as in the prior art (FIGS. 13 to 14), and the inside of the bearings 25, 25a to 25d. Since a braking means for generating a compression force is built in, space saving is possible, and a compact compression bending apparatus can be configured.
(2) Since braking is performed by pressing the top surface of the annular brake ring, a strong and stable braking force (compression force to the metal pipe) can be obtained.
(3) By not only applying a constant compressive force to the metal pipe by making the brake force of the brake bearing constant, but also changing the compressive force applied to the metal pipe during processing by changing the brake force by the brake bearing. You can also

(4) Unlike conventional compression bending, no external force is applied to apply a compressive force, reducing the occurrence of overturning moments (forces that tilt the spindle and clamp arm) that cause twisting of the bending pipe. I can do it.
(5) Since only a braking force for suppressing the rotation of the clamp arm is applied, a bending moment is not generated in the support shaft portion (rotating shaft) of the clamp arm by applying an external force as in the prior art. Therefore, the support shaft portion (rotating shaft) of the clamp arm can be made thin, and a compact and simple compression bending apparatus can be realized.
(6) It is not necessary to provide a large-scale mechanism for applying a compressive force around the rotation axis of the clamp arm, and a brake-equipped bearing that generates a compressive force can be placed at any position on the rotary axis of the clamp arm. Therefore, the degree of freedom in device design is high.

(7) Since driving means (compression hydraulic motor or hydraulic cylinder) for generating a compression force that has been required in the past is not required, it is advantageous in comparison with the conventional apparatus in terms of energy saving and space saving.
(8) Since the control drive unit that generates and controls the compression force can be simplified and simplified, the processing accuracy of the bending pipe can be improved and the processing quality can be improved.
(9) Since the structure of the clamp arm (compression generating mechanism) is simple and its control mechanism and control are simple, the manufacturing cost of the processing apparatus can be reduced, and it is hard to break down and easy to maintain. The running cost of the compression bending apparatus can be reduced. Therefore, it is possible to reduce the manufacturing (processing) cost of the bent pipe.

DESCRIPTION OF SYMBOLS 11 Metal pipe 12 Induction heating coil 13 Clamp arm 14 Clamp part 15 Arm main body 16 Apparatus frame 17 Propulsion part 18 Rear clamp 19 Propulsion hydraulic cylinder 20 Guide roller 21, 61 Support shaft part 22 Rotating shaft part 23 Support frame part 24 Support Shaft feet 25, 25a, 25b, 25c, 25d Ball bearing with brake 26 Ball bearing 31 Inner ring 32 Outer ring 33 Rolling element (ball)
34 Brake ring 35 Annular groove 36 Oil supply hole 37 Locking portion 38 Engaging portion 39 Brake pad 40 Bolt hole 41 Flange portion 51, 52 Plate-shaped ring member 62 Central shaft portion 63 Support shaft main body portion 71 Large gear 72 Small gear 73 Hydraulic pressure Motor C Center of rotation of clamp arm S Seal material

Claims (5)

A heating means for heating a part of the metal pipe to be bent in an annular shape;
Propulsion means for propelling the metal tube in the tube axis direction toward the heating means;
A clamp arm that grips the metal tube and is rotatable about a support shaft portion. The clamp arm grips a front portion of the heating portion of the metal tube by the heating means, and the gripping point is a metal by the propulsion means. Guide means for turning about the support shaft as the tube is propelled, thereby applying a bending moment to the metal tube;
A bearing that rotatably supports the clamp arm in the support shaft,
A metal pipe bending apparatus comprising:
The bearing is
An inner ring and an outer ring arranged coaxially;
A support body interposed between the inner ring and the outer ring so that the inner ring and the outer ring can rotate relative to each other;
And one or more bearings with brakes provided with brake means that abuts against the inner ring or the outer ring and suppresses relative rotation between the inner ring and the outer ring by a frictional force,
A metal pipe bending apparatus, wherein a compression force can be applied to the metal pipe by suppressing rotation of the clamp arm by the brake means during the bending of the metal pipe. 2 or more of the bearings,
The bending apparatus for a metal pipe according to claim 1, wherein two or more of these bearings are the bearings with a brake. The brake means includes
A plurality of plate-shaped ring members arranged to be connected to the inner ring and stacked in the rotation axis direction of the bearing;
A plurality of plate-like ring members connected to the outer ring and arranged to be stacked in the direction of the rotation axis of the bearing,
The ring member connected to the inner ring and the ring member connected to the outer ring are arranged so as to be alternately sandwiched between each other, and the ring member connected to the inner ring with relative rotation of the inner ring and the outer ring And a ring member connected to the outer ring relatively rotate,
The said brake means was further equipped with the press member which presses the ring member connected to the said inner ring, and the ring member connected to the said outer ring mutually, and suppresses relative rotation between these ring members. Metal pipe bending machine. A step of heating a part of a metal pipe to be bent in a ring shape by a heating means;
The metal tube is propelled in the tube axis direction toward the heating means while gripping the position near the front side of the heating portion of the metal tube by a clamp arm that can rotate around the support shaft portion. Adding a bending moment to
A method of manufacturing a metal pipe having a bent pipe part,
The clamp arm is rotatably supported via a bearing at the support shaft portion,
The bearing is
An inner ring and an outer ring arranged coaxially;
A support body interposed between the inner ring and the outer ring so that the inner ring and the outer ring can rotate relative to each other;
A brake bearing comprising: brake means that abuts against the inner ring or the outer ring and suppresses relative rotation of the inner ring and the outer ring by friction force;
The manufacturing method includes:
During the step of applying a bending moment to the metal tube, the brake means suppresses the relative rotation between the inner ring and the outer ring, thereby suppressing the rotation of the clamp arm, thereby applying a compressive force to the metal tube. A method of manufacturing a metal pipe having a bent pipe part. 2 or more of the bearings,
Two or more of these bearings are the brake bearings,
The manufacturing method of the metal pipe provided with the curved pipe part according to claim 4, wherein the rotation of the clamp arm is suppressed by the two or more bearings with brakes and a compressive force is applied to the metal pipe.

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