Metal strip bending equipment

Abstract

To provide a metal strip material bender that allows for accurate bending under simple control and reducing the size thereof.SOLUTION: A bender includes a heating device 12 that locally heats up a small fraction in an axial direction of a metal strip material 1, a cooling device that performs cooling immediately after a heated portion of the metal strip material by the heating device is bent, a thrusting device 21 that relatively moves the metal strip material in the axial direction with respect to the heating device, and a bending arm 13 that has a clamp 15 to grip a tip of the metal strip material forward in a travel direction of the heated portion by the heating device and is rotatable about a rotary support shaft 14, in which the clamp rotatably grips the metal strip material about an axis 16 parallel with the rotary support shaft. The bender comprises an arm support-shaft mover 31 that can move the rotary support shaft of the bending arm in a direction parallel with the axial direction of the metal strip material simultaneously when the metal strip material is moved relatively to the heating device by the thrusting device.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a bending device for metal strip material. Place In particular, the present invention relates to a technique for continuously bending a metal strip such as a steel pipe. [Background technology]

[0002] Metal strip materials are widely used today in industrial facilities such as plants, factories, and power plants as pipes for transporting fluids such as oil, gas, and various liquids, and as framework structural materials for civil engineering buildings such as bridges and stadium roofs. Metal pipes, one of these metal strip materials (although the subject matter of the present invention is not limited to pipes, the following explanation will be given taking pipes as an example as a typical embodiment), are standardized pipes that are pre-formed into a predetermined shape, i.e., straight pipes or irregular pipes such as elbows and bends, while pipes that are bent from straight pipes according to the object of construction (hereinafter referred to as "bent pipes") are also widely used because they can flexibly meet the requirements for various curvatures and pipe shapes.

[0003] Processing equipment for manufacturing such bent pipes generally includes an induction heating coil that heats a small axial section of the metal pipe to be processed in a circular shape, a propulsion device that propels the metal pipe toward the induction heating coil, and a clamp arm (also called a "bending arm" or simply "arm") that grips the metal pipe and rotates around a support axis to restrict the path of the metal pipe to an arc.

[0004] During processing, the metal tube is pushed toward the induction heating coil while being held by a clamp arm at the front end (the tip end) of the metal tube from the induction heating coil. The clamp arm rotates around a support shaft as the metal tube is advanced, which applies a bending moment to the part of the metal tube heated by the induction heating coil, causing continuous plastic deformation of the metal tube and bending it in an arc.

[0005] Further, the following patent documents disclose a method for bending such a metal strip material. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2002-120019 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in conventional bending devices, generally, in order to manufacture bent pipes with a large radius of curvature, a correspondingly long arm is required, which results in a problem that the arm tends to bend and shift when rotating, making it difficult to improve processing accuracy.

[0008] On the other hand, according to the method described in the above-mentioned Patent Document 1, by moving the pivot shaft of the bending arm, bending with a large radius of curvature can be performed even with a relatively short arm, and it is also possible to flexibly respond to various curvatures and processing shapes. However, in the method described in this document, it is necessary to move the arm's pivot shaft in both the X-axis and Y-axis directions at the same time as the bending progresses, which makes the control complicated. In addition, the device described in this document is equipped with an X-axis carriage moving device 7 and a Y-axis carriage moving device 8, so the device becomes large, and there is a problem that a large installation space is required.

[0009] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to enable high-precision bending with simpler control than conventional techniques, and to reduce the size of a bending device. [Means for solving the problem]

[0010] In order to solve the above problems and achieve the object, the metal strip bending apparatus of the present invention is an apparatus for bending metal strip material which includes a heating device that locally heats a small axial section of the metal strip material to be processed, a cooling device that cools the heated portion of the metal strip material heated by the heating device immediately after the heated portion is bent and deformed, a propulsion device that moves the metal strip material relative to the heating device in the axial direction, and a bending arm that has a clamp that holds the tip side of the heated portion of the metal strip material heated by the heating device in the traveling direction and can rotate around a pivot axis.

[0011] The clamp holds the metal strip so as to be rotatable about an axis parallel to the pivot shaft. The bending device further includes an arm pivot moving device that moves the metal strip relative to the heating device by the propelling device and simultaneously moves the pivot shaft of the bending arm in a direction parallel to the axial direction of the metal strip.

[0012] In this application, a three-dimensional orthogonal coordinate system is assumed, with the position of the pivot shaft of the bending arm at the start of the bending process as the origin, and consisting of mutually orthogonal X-, Y-, and Z-axes, with the pivot shaft of the bending arm as the Z-axis and the moving direction of the pivot shaft as the Y-axis, and the bending process is performed within a plane including the X- and Y-axes. The direction of the metal tube's advance, i.e., the direction from the advancement device toward the induction heating coil (the axial direction of the metal tube before bending deformation) and the Y-axis (the moving direction of the pivot shaft) are parallel to each other.

[0013] In the bending processing apparatus of the present invention, the arm support shaft moving device moves the bending arm's pivot shaft (which coincides with the Z axis in the initial position) in a direction parallel to the propulsion direction (Y axis direction), and by controlling the moving speed, it is possible to produce a bent pipe with the desired radius of curvature.

[0014] In particular, even when manufacturing a bent pipe with a large radius of curvature, it is possible to use a short arm by moving the pivot axis of the arm, which makes it possible to avoid or reduce the effects of arm bending and rotational deviation during processing, thereby improving processing accuracy. A more specific processing method will be described in detail later in the embodiment with reference to the drawings.

[0015] Furthermore, in the present invention, the movement of the pivot shaft is controlled in only one direction (the Y-axis direction), so the control can be simplified compared to when two directions (the X-axis and Y-axis directions) are controlled.

[0016] In addition, in the present invention The propulsion device and the arm support shaft moving device are integrally configured in order to make the bending device compact so that it can be installed in a small space.

[0017] Furthermore, in order to bend the metal strip in a certain direction, the arm spindle moving device typically moves the arm's pivot spindle in a direction parallel to the axial direction (Y-axis direction) at a speed (sometimes called the "spindle moving speed") Vb slower than the relative moving speed (sometimes called the "thrust speed") Va of the metal strip by the thrust device, but the thrust speed Va and the spindle moving speed Vb are not always constant values ​​and may be changed in various ways during processing in order to perform, for example, bending processing with a large radius of curvature or processing in which the radius of curvature is partially different. Furthermore, the spindle moving speed Vb may be zero (i.e., stopped) or negative (i.e., movement in the opposite direction).

[0018] In the present invention, the base end of the bending arm may further include an arm rotation drive device capable of applying either or both of a rotational force that promotes the rotation of the bending arm about the pivot shaft and a braking force that suppresses the rotation of the bending arm, in order to increase or decrease the bending moment applied to the metal strip and to enable more precise processing control.

[0019] For the same reason, a clamp rotation drive device capable of applying either or both of a rotational force about an axis parallel to the pivot axis and a braking force to the clamped portion of the metal strip may be provided at the tip of the bending arm. Effect of the Invention

[0022] According to the present invention, it is possible to perform bending with high accuracy with simpler control than in the past, and to reduce the size of the bending device.

[0023] Other objects, features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a plan view showing a schematic diagram of a bending apparatus according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing a bending arm of the bending device according to the embodiment. [Diagram 3] FIG. 3 is a plan view showing a first processing example by the bending device according to the embodiment. [Figure 4] FIG. 4 is a plan view showing a second processing example by the bending device according to the embodiment. [Diagram 5] FIG. 5 is a conceptual diagram showing a processing state by the bending device according to the embodiment. [Figure 6] FIG. 6 is a plan view showing a third processing example by the bending device according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] [Device configuration] A bending device according to an embodiment of the present invention will be described with reference to Figures 1 and 2. Each figure shows two-dimensional Cartesian coordinates representing the front-rear and left-right directions, three-dimensional Cartesian coordinates representing the front-rear and left-right and up-down directions, and an XYZ three-dimensional Cartesian coordinate system with the support shaft of the bending arm as the origin (the Z axis in Figure 1 is perpendicular to the paper surface), and the description will be based on these directions.

[0026] As shown in FIG. 1, a bending apparatus 11 according to one embodiment of the present invention includes an induction heating coil 12 for heating a small section in the direction of an axis 1a of a metal tube 1 to be processed, a cooling device (not shown) for cooling the small section heated by the induction heating coil 12 immediately after the small section is bent, a propulsion device 21 for pushing the metal tube 1 forward (parallel to the Y-axis) toward the induction heating coil 12, a bending arm 13 having a clamp 15 at its tip for gripping the front side of the section heated by the induction heating coil 12 and rotating within the XY plane around a support shaft 14 (Z-axis), a support shaft moving device 31 for moving the support shaft 14 of the bending arm 13 in the front-rear direction (Y-axis direction), a propulsion drive unit (propulsion drive circuit) 25 for driving the propulsion device 21, a support shaft drive unit (support shaft drive circuit) 35 for driving the support shaft moving device 31, and a control unit 41 for controlling the propulsion drive unit 25 and the support shaft drive unit 35. 2 and subsequent figures, the propulsion drive unit 25, the support shaft drive unit 35, and the control unit 41 are omitted from the illustration.

[0027] The control unit 41 controls the pushing speed Va of the metal tube 1 by the pushing device 21 via the pushing drive unit 25, and also controls the moving speed Vb of the support shaft 14 by the support shaft moving device 31 via the support shaft drive unit 35. The clamp 15 is provided at the tip of the bending arm 13 so as to be rotatable around an axis 16 parallel to the Z axis (so as to be able to rotate freely as the bending process progresses).

[0028] The propulsion device 21 has a propulsion rod 22 that is equipped with a propulsion arm 22a that grips the rear end of the metal tube 1 and extends parallel to the axis 1a of the metal tube 1, and a propulsion device main body 23 that moves the propulsion rod 22 forward. The propulsion device main body 23 has a motor 24 that is a power source, a pinion (not shown) that is rotated by the motor 24, and a rack (not shown) that meshes with the pinion and transmits the power of the motor 24 to the propulsion rod 22.

[0029] The shaft moving device 31 also has a shaft moving rod 32 that extends parallel to the axis 1a of the metal tube 1 and is connected to the shaft 14 of the bending arm 13, and a shaft moving device main body 33 that moves the shaft moving rod 32 in the front-rear direction. Similar to the propulsion device main body 23, the shaft moving device main body 33 includes a motor 34 that is a power source, a pinion (not shown) that is rotated by the motor 34, and a rack (not shown) that meshes with the pinion and transmits the power of the motor 34 to the shaft moving rod 32.

[0030] The shaft moving device 31 can move the shaft 14 not only forward but also backward, for example, by rotating the motor 34 in the reverse direction. In this embodiment, in order to make the bending apparatus 11 compact, the propulsion device 21 (propulsion device main body 23) and the shaft moving device 31 (shaft moving device main body 33) are integrated together.

[0031] According to the bending apparatus of this embodiment, the following bending can be performed.

[0032] [Processing example 1] Fig. 3 shows an example in which bending is performed by driving only the propelling device 21 without driving the support shaft moving device 31 from the initial state shown in Fig. 1. In this case, the radius of curvature r1 of the metal tube 1 becomes equal to the length L of the bending arm 13 (the distance from the rotation center of the support shaft 14 to the center of the clamp 15).

[0033] [Processing example 2] In contrast, Fig. 4 shows an example in which bending is performed by driving the propulsion device 21 as well as the shaft moving device 31 from the initial state shown in Fig. 1, and moving the swivel shaft 14 of the bending arm 13 forward (in the Y-axis direction). That is, the metal tube 1 is pushed forward (in a direction parallel to the Y-axis) at a constant speed Va by the propulsion device 21, and at the same time, the swivel shaft 14 of the bending arm 13 is moved forward (in the Y-axis direction) at a speed Vb that is slower than the propulsion speed Va by the shaft moving device 31. This makes it possible to manufacture a bent tube 1 with a radius of curvature r2 that is larger than the example of processing shown in Fig. 3 (radius of curvature r1).

[0034] To further explain this point, with reference to Figure 5, Figure 5 is a line diagram showing the axis of a bent pipe, in which symbol 51a indicates the axis of the bent pipe in the above-mentioned processing example 1 (Figure 3), and symbol 52a indicates the axis of the bent pipe in processing example 2 (Figure 4), which has a larger radius of curvature than axis 51a.

[0035] Here, to manufacture a bent pipe having an axis 52a with a large radius of curvature, multiple points a0 to a5 are imagined on the axis 52a to be formed, and the support shaft 14 of the arm 13 is moved so that the tip of the arm 13 (the part where the metal pipe 1 is gripped by the clamp 15 / hereinafter referred to as the "clamp point") passes through these points a0 to a5.

[0036] That is, the arm 13 is rotated by the forward thrust (thrust speed Va) of the metal tube 1, and the support shaft 14 of the arm 13 is moved by the support shaft moving device 31 at a moving speed Vb so as to reach a point b1 on the Y axis from the origin 0 until the clamp point moves from point a0 to point a1. Similarly, the support shaft 14 is moved at a moving speed Vb so as to reach a point b2 on the Y axis from point b1 until the clamp point moves from point a1 to point a2. Similarly, the support shaft 14 is moved at a moving speed Vb so as to reach a point b2 from point b3 until the clamp point moves from point a2 to point a3, at a moving speed Vb so as to reach a point b3 from point b4 until the clamp point moves from point a3 to point a4, and at a moving speed Vb so as to reach a point b4 from point b5 until the clamp point moves from point a4 to point a5. This makes it possible to manufacture a bent tube having an axis 52a passing through points a0 to a5. In this embodiment, six points (points a0 to a5) are assumed for ease of understanding, but from the viewpoint of improving processing accuracy, the more points there are, the more preferable.

[0037] Furthermore, if the movement speed Vb of the support shaft 14 is made even faster than in the above processing, each of the positions b1 to b5 of the support shaft 14 will move to a position further forward on the Y axis, making it possible to manufacture a bent pipe having an axis 53a with an even larger radius of curvature than the axis 52a. In other words, the closer the support shaft movement speed Vb is to the propulsion speed Va (the smaller the difference between Va and Vb), the larger the radius of curvature can be, and conversely, the larger the difference between the propulsion speed Va and the support shaft movement speed Vb, the smaller the radius of curvature can be.

[0038] [Processing example 3] It is also possible to manufacture a bent pipe having multiple sections with different radii of curvature, rather than a constant radius of curvature over the entire length. For example, Fig. 6 shows an example of manufacturing a bent pipe having two types of radii of curvature, i.e., a section with a large radius of curvature r4 and a section with a small radius of curvature r5.

[0039] As a specific processing method, when processing is performed with the thrust speed Va constant, the support shaft movement speed Vb is increased during the initial period in which the section with radius of curvature r4 is formed, and then the support shaft movement speed Vb is decreased while the section with radius of curvature r5 is formed (in the example shown in Figure 6, Vb = 0 during this period), and a bent pipe with a section with a large radius of curvature r4 and a section with a small radius of curvature r5 can be manufactured.

[0040] In the same manner, it is possible to manufacture a bent pipe having three or more sections with different radii of curvature. Furthermore, it is also possible to form a straight section by making the support shaft moving speed Vb equal to the propulsion speed Va, or to form a section whose radius of curvature is smaller than that of the axis 51a by moving the support shaft in the opposite direction (backward).

[0041] Furthermore, in the processing apparatus of this embodiment, the spindle 14 and clamp 15 of the bending arm 13 are provided so as to be freely rotatable, but as shown by symbols 42 and 43 in FIG. 6, the spindle 14 or clamp 15 may be provided with a rotational drive device (e.g., a motor, etc.) that applies a rotational force to the spindle 14 or clamp 15, or a braking device (e.g., a mechanical brake or a regenerative brake of a motor, etc.) that applies a braking force to the rotation that occurs as the bending process progresses. By providing such a rotational drive device or braking device, it is also possible to perform more precise processing control.

[0042] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and it will be apparent to those skilled in the art that various modifications can be made within the scope of the claims.

[0043] For example, in the above embodiment, a motor is used as the power source, but a hydraulic or pneumatic cylinder or other power source may be used. In addition, in the above embodiment, a pinion and a rack are used as the power transmission means, but it is also possible to use, for example, a sprocket and a chain, or a ball screw. Furthermore, in the processing example of the above embodiment, the advancing speed Va of the metal tube is constant, but in the present invention, the speed difference between the advancing speed Va and the support shaft moving speed Vb is important, and the advancing speed Va does not necessarily have to be constant. In addition, the object of bending is not limited to a tubular member (hollow member), and for example, a long rod-shaped member (solid member) can also be processed. [Explanation of symbols]

[0044] 1 metal tube 1a Axis of metal tube 11 Bending equipment 12 Induction heating coil 13 Bending Arm 14 Bending arm support shaft (swivel support shaft) 15 Clamp 16 Clamp shaft (rotating shaft) 21 Propulsion device 22 Propulsion Rod 22a Propulsion arm 23 Propulsion device main body 24 Motor 25 Propulsion Drive Unit 31 Spindle moving device 32 Support shaft moving rod 33 Support shaft moving device main body 34 Motor 35 Shaft drive unit 41 Control section 42 Rotational or braking force applied to the support shaft 43 Rotational or braking force applied to clamp

Claims

1. A heating device for locally heating a small section in the axial direction of the metal strip material to be processed; A cooling device that cools the heated portion of the metal strip material immediately after the heated portion of the metal strip material is bent and deformed by the heating device; A propulsion device that moves the metal strip relative to the heating device in an axial direction; A bending arm having a clamp that holds the tip side of the metal strip in the advancing direction from the heated portion by the heating device and that is rotatable around a pivot shaft; A bending apparatus for metal strips, comprising: The clamp holds the metal strip rotatably around an axis parallel to the pivot shaft, the bending apparatus further includes an arm support shaft moving device that is capable of moving a pivot shaft of the bending arm in a direction parallel to the axial direction of the metal strip when the metal strip is moved relative to the heating device by the propulsion device, The propulsion device and the arm support shaft moving device are integrated together. A bending apparatus for metal strip material.

2. The arm support shaft moving device moves the pivot support shaft in a direction parallel to the axial direction at a speed slower than a relative moving speed of the metal strip material by the propulsion device. The metal strip bending apparatus according to claim 1 .

3. The base end of the bending arm is further provided with an arm rotation drive device capable of applying either or both of a rotational force that promotes the rotation of the bending arm around the rotation support shaft and a braking force that suppresses the rotation of the bending arm.

3. The bending apparatus for metal strip material according to claim 1 or 2.

4. The bending arm further includes a clamp rotation drive device at a tip end thereof, capable of applying either or both of a rotational force about an axis parallel to the pivot shaft and a braking force to the clamped portion of the metal strip material. The bending apparatus for metal strip material according to any one of claims 1 to 3.

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