Variable bend radius large diameter tube dieless bender

Abstract

A variable bending radius large diameter pipe dieless bending machine, comprising a heating mechanism (10), a swing arm mechanism (20), a radius adjusting mechanism (30) and a fixing mechanism (40), the heating mechanism is used for heating the through part of the large diameter pipe to above the deformation temperature to continuously form a bending part; the swing arm mechanism (20) is used for providing a bending guide deformation force to the bending part in a pivot position C1; the swing arm mechanism (20) comprises a swing arm shaft (21), a movable chuck (22) and a pivot base (23), one end of the swing arm shaft (21) is fixedly connected with the movable chuck (22), the other end is fixedly connected with the pivot base (23), the movable chuck (22) is fixedly connected with the bending part, and the pivot base (23) is rotatably fixed in the pivot position C1; the radius adjusting mechanism (30) is used for adjusting the pivot position C1 before bending operation; and the fixing mechanism (40) is used for fixing the pivot base (23) in the pivot position C1. The adjustable radius arc bending can be realized.

Description

Technical Field

[0001] This invention relates to the field of pipe bending machine manufacturing technology, specifically to a moldless pipe bending machine for large-diameter pipes with variable bending radius. Background Technology

[0002] Long-distance oil and gas pipeline projects often require pipe bends to change the pipeline direction. A typical pipeline is 12m long with a wall thickness of 38mm. The pipeline needs to be bent every 300m, with a maximum bending angle of 0.4° each time. The cumulative value of each bending angle reaches the required total angle. Pipes with a diameter of 640mm or more are considered large-diameter pipes. Pipe bending machines are mainly used for the plastic forming of pipes during metal processing. To enable on-site pipe bending operations, pipe bending machines need to reduce transportation and processing costs and simplify the manufacturing process.

[0003] The working principle of a pipe bending machine is as follows: the bending radius *r* is the distance from the pivot point of the swing arm to the center of the moving chuck. A medium-frequency induction heating coil is installed in the bending area of ​​the pipe. First, the bending area of ​​the pipe is heated to a certain temperature by a medium-frequency induced current. Then, the moving chuck moves along the arc of the bending radius *r*, causing the pipe to bend, thus achieving bending of the heated portion. The bending radius of the pipe can be controlled by adjusting the length of the swing arm. It can form bends with different bending angles but the same preset bending radius.

[0004] Existing large-diameter pipe bending machines have the following disadvantages.

[0005] Disadvantage ①: It is difficult to change the bending radius. The pivot seat needs to be reinstalled. The pivot seat is a heavy-duty base. To change the fixed position of the pivot seat, a gantry crane is needed to lift the pivot seat, adjust it to the required radius length, and then tighten it with multiple fastening bolts to fix it.

[0006] Disadvantage 2: The bending radius cannot be changed during operation. Once the pivot is fixed in position, it is secured with multiple bolts. During bending operations, the bending radius cannot be dynamically changed. To change it, the machine must be stopped, repositioned, and reinstalled before bending to the next radius can begin.

[0007] Disadvantage 3: The bending force cannot precisely maintain an extremely low constant speed. The bending force is from a hydraulic cylinder. Because the hydraulic oil in the enclosed space has a non-linear hydraulic spring force, its motion transmission has a lag. The piston rod of the hydraulic cylinder exhibits an intermittent motion state of "acceleration, deceleration, stalling, acceleration, deceleration, stalling" at low speeds, which is called the crawling phenomenon. This crawling phenomenon makes it impossible to maintain an extremely low constant speed.

[0008] Therefore, there is an urgent need in this field for a pipe bending machine that can change the bending radius before bending operations with extremely simple operation, dynamically change the bending radius during bending operations at minimal cost, and maintain a precise, extremely low constant speed. This is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0009] In view of the defects existing in the prior art, the purpose of this invention is to provide a large-diameter pipe bending machine with variable bending radius without mold, which solves the technical problems of "① difficulty in changing the bending radius; ② inability to change the bending radius during operation; ③ precise extremely low constant speed" in pipe bending machines.

[0010] The objective of this invention is achieved by providing a moldless pipe bending machine for large-diameter pipes with a variable bending radius, comprising: A heating mechanism is used to slowly pass a large-diameter tube along a straight path L1 through the heating mechanism, which heats the passing part of the large-diameter tube to above the deformation temperature to continuously form a curved part; The rocker arm mechanism is used to provide bending guiding deformation force to the aforementioned curved part. The rocker arm mechanism includes a rocker arm shaft, a movable chuck, and a pivot seat. One end of the rocker arm shaft is fixedly connected to the movable chuck, and the other end is fixedly connected to the pivot seat. The movable chuck is fixedly connected to the curved part, and the pivot seat is rotatably fixed at the pivot position C1. The diameter adjustment mechanism is used to adjust the pivot position C1 before bending operations; the diameter adjustment mechanism includes a three-point slide rail and a diameter adjustment cylinder, the pivot seat is slidably disposed on the three-point slide rail, and the diameter adjustment cylinder is fixedly connected to the pivot seat; A fixing mechanism is used to fix the pivot seat at the pivot position C1.

[0011] Furthermore, the pivot seat includes a seat body, which includes three guide slides that are slidably supported on a three-point slide rail. The three-point slide rail includes an integrally connected I-shaped top rail and an I-shaped bottom rail. The I-shaped bottom rail is parallel to the two I-shaped top rails and is arranged in an equilateral triangle in cross-section.

[0012] Furthermore, the pivot seat also includes a pivoting part and a fixed chuck. The pivoting part is located on the top of the seat body, directly opposite the top of the I-beam bottom rail with its rotation center. The fixed chuck is integrally connected to one side of the pivoting part. The axis of the fixed chuck forms a perpendicular straight line with the axis of the pivoting part, and the distance between the two axes is L = r1 + r2 + gap, where r1 is the radius of the swing arm axis, r2 is the radius of the pivoting part, and gap is the inter-axis allowance. gap < .

[0013] Furthermore, the fixing mechanism includes multiple bolts and nuts. The multiple bolts are inserted into multiple through holes of the pivot seat and the nuts are screwed into the ends of the bolts. The nuts abut against the lower surface of the I-shaped bottom rail or the I-shaped top rail. First, the fixing mechanism of the I-shaped bottom rail is tightened, and then the fixing mechanisms of the two I-shaped top rails are tightened alternately.

[0014] Furthermore, it also includes an elliptical mechanism, which replaces the pivot seat to achieve elliptical bending; the elliptical mechanism includes an integrally connected bidirectional rail base layer and a connecting rod layer, the bidirectional rail base layer includes a horizontal slide rail and a vertical slide rail that intersect perpendicularly at the central origin, the horizontal slide rail is slidably disposed on the horizontal slide rail, and the vertical slide rail is slidably disposed on the vertical slide rail; the connecting rod layer includes a rocker arm connecting rod, one end of the rocker arm connecting rod is hinged to the central origin; the vertical slide rail is hinged to the tail end of the rocker arm shaft, the horizontal slide rail is hinged to the midpoint of the rocker arm shaft, the other end of the rocker arm connecting rod is hinged to the tail 1 / 4 position of the rocker arm shaft 21, and the head end of the rocker arm shaft is fixedly connected to a movable chuck.

[0015] Furthermore, it also includes a constant speed mechanism for driving the large-diameter pipe W forward at an extremely slow and constant speed. The constant speed mechanism includes a slow rotation source, a straightening conversion mechanism, and a moving plate connected in sequence. The moving plate is vertically mounted on a straight track. The straightening conversion mechanism includes a synchronous rotating shaft, and a chain pair is provided between the synchronous rotating shafts. The upper chain of the chain pair is fixedly connected to the moving plate. The other end of the large-diameter pipe opposite to the curved part abuts against the moving plate.

[0016] Furthermore, the slow-speed power source includes a high-power motor, a first reduction gear, and a second reduction gear. The output shaft of the high-power motor is connected to the first reduction gear, and the output shaft of the first reduction gear is connected to the second reduction gear, thereby reducing the speed of the power source by N times, where N≥1000.

[0017] A moldless pipe bending machine for large-diameter pipes with variable bending radius is available. It can bend pipes in a fixed-diameter circular arc or an elliptical arc. The bending radius of the fixed-diameter circular arc can be flexibly adjusted. It features slow and constant-speed feeding, making it easy to transport and install. It can bend pipes on-site, solving practical problems in pipe bending and has great practical value. Attached Figure Description

[0018] Figure 1 This is a top view of Embodiment 1 of the present invention, a large-diameter pipe bending machine with variable bending radius; Figure 2 This is a front view of Embodiment 1 of the present invention, a large-diameter pipe bending machine with variable bending radius; Figure 3 This is a top view of the constant speed mechanism 50 of Embodiment 2 of the present invention, a large-diameter pipe bending machine with variable bending radius. Figure 4 This is a partial cross-sectional view of Embodiment 1 of the present invention, a large-diameter pipe bending machine with variable bending radius (the hydraulic cylinder connecting rod 70 is in an automatic clamping state). Figure 5 This is Embodiment 1 of a large-diameter pipe bending machine with variable bending radius according to the present invention. Figure 1 A partial sectional view (the hydraulic cylinder connecting rod 70 is in the automatic opening state).

[0019] Figure 6This is a top view of the elliptical mechanism 60 of Embodiment 3 of the moldless pipe bending machine for large diameter pipes with variable bending radius according to the present invention.

[0020] The reference numerals in the above figure: 10 Heating mechanism, 11 Induction coil 20. Swing arm mechanism; 21. Swing arm shaft; 22. Moving chuck; 23. Pivot seat; 24. Pivot part; 25. Seat body; 26. Fixed chuck; 27. Side plate; 28. Clamping cylinder; 29. ​​Guide slide part. 30 Adjusting mechanism, 31 Three-fixed slide rail, 32 Adjusting cylinder, 33 Top slide rail, 34 H-beam rail, 35 Bottom slide rail, 36 Fixing part 40 Fixing mechanism, 41 Bolt, 42 Nut 50 Constant speed mechanism, 51 Slow-speed rotation source, 52 Direct-to-vertical conversion, 53 Moving plate, 54 Linear track, 55 Lug device, 56 Chain pair, 57 Upper chain pair 60 Elliptical mechanism, 61 Two-way rail base, 62 Central pivot, 63 Small connecting rod, 64 Horizontal slide rail, 65 Vertical slide rail, 66 Horizontal slider, 67 Vertical slider 70 Hydraulic cylinder connecting rod, 71 Stationary half mold, 72 Rotating half mold, 73 Left elbow rod, 74 Right elbow rod, 75 Hydraulic cylinder, 76 Pivot Detailed Implementation

[0021] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Example

[0022] The center of the moving chuck is at the pivot position C1. Adjust and fix the bending radius before operation.

[0023] like Figure 1 As shown, a large-diameter pipe bending machine with variable bending radius includes... Heating mechanism 10 is fixed at the head end of the straight path L1. A large-diameter tube slowly passes through the heating mechanism 10 along the straight path L1 via a moving roller. The heating mechanism 10 is used to heat the passing part of the large-diameter tube to above the deformation temperature to continuously form a curved part. The swing arm mechanism 20 is used to provide bending guidance deformation force to the bending part of the large-diameter pipe. It includes a swing arm shaft 21, a movable chuck 22, and a pivot seat 23. One end of the swing arm shaft 21 is fixedly connected to the movable chuck 22, and the other end is fixedly connected to the pivot seat 23. The movable chuck 22 is fixedly connected to the head end of the large-diameter pipe, and the pivot seat 23 is rotatably fixed at the pivot position C1. The lower part of the movable chuck 22 is provided on the chuck wheel 22.1.

[0024] The diameter adjustment mechanism 30 is used to adjust the pivot position C1 of the pivot seat 23 before bending operation. It includes a slide rail 31 and a diameter adjustment cylinder 32. The pivot seat 23 is slidably disposed on the slide rail 31, and the diameter adjustment cylinder 32 is fixedly connected to the pivot seat 23. The fixing mechanism 40 is used to fix the pivot seat 23 at the pivot position C1. At the pivot position C1, the fixing mechanism 40 fixes the pivot seat 23 to the foundation.

[0025] The heating mechanism 10 includes an induction coil 11, which is fixed to the frame.

[0026] The fixing mechanism 40 includes multiple bolts 41 and nuts 42. The multiple bolts 41 are inserted into multiple through holes in the pivot seat 23 and the nuts 42 are screwed onto the ends of the bolts 41.

[0027] The diameter adjustment mechanism 30 includes three fixed slide rails 31, two integrally connected top slide rails 33 arranged in an equilateral triangle, and an H-shaped steel rail 34. The two parallel slide rails 31 are fixedly mounted on the frame. The H-shaped steel rail 34 is mounted parallel to the slide rails at the middle position below the slide rails 31 on the frame. The H-shaped steel rail 34 is fixed to the foundation. The H-shaped steel rail 34 and the two slide rails 31 form an equilateral triangle in cross-section. The H-shaped steel rail 34 is horizontally and integrally connected to the outer slide rail part 35 on the outer side of the web plate, and horizontally and integrally connected to the fixing part 36 on the inner side of the web plate.

[0028] The pivot seat 23 includes a pivot portion 24, a seat body 25, and a fixed chuck 26. A pivot is fixed to the top of the seat body 25, and the pivot is rotatably connected to the pivot portion 24. The fixed chuck 26 is integrally connected to one side of the pivot portion 24. The axis of the fixed chuck 26 forms skew lines with the axis of the pivot portion 24, and the two axes are perpendicular. The distance between the two axes is L = r1 + r2 + gap, where r1 is the radius of the swing arm shaft 21, r2 is the radius of the pivot portion 24, and gap is the inter-axis allowance. gap < The base body 25 has three guide slides 29 arranged in an equilateral triangle 28. The two top guide slides 29 are slidably fitted to the tops of the two slide rails 31, and the bottom guide slide 29 is slidably mounted on the outer slide rail 35 of the H-shaped steel rail 34. The bottom guide slide 29 has a through hole through which a bolt passes. A nut 42 abuts against the fixing part 36 of the H-shaped steel rail 34 and is threadedly fitted to the bolt 41 to secure the pivot seat 23 in the pivot position C1. One end of the pivot seat 23 has a side plate 27. The cylinder end of the adjusting cylinder 32 is fixedly mounted on the H-shaped steel rail 34, and the piston end of the adjusting cylinder 32 is located at the center of the equilateral triangle 18 of the slide rail 31 and the side plate 27. The bottom guide slide 24 has a radius scale 29. The bottom guide slide 26 of the pivot seat 23 has a pointer horizontally positioned opposite the center line of the pivot part, pointing to the radius scale 29.

[0029] The fixed chuck 26 switches between automatic opening and automatic clamping states via the hydraulic cylinder connecting rod 70. The fixed chuck 26 includes a stationary half mold 71 and a rotating half mold 72. The rotating half mold 72 is pivotally connected to the stationary half mold 71. The hydraulic cylinder connecting rod 70 includes left and right elbow rods 73 and a right elbow rod 74. The left elbow rod 73 is hinged to the right elbow rod 74 at the pivot 76. The other end of the left elbow rod 73 is hinged to the rotating half mold 72. The other end of the right elbow rod 74 is hinged to the stationary half mold 71. The piston end of the hydraulic cylinder 75 is hinged to the pivot 76, and the piston end of the hydraulic cylinder 75 is hinged to the pivot part 24. Example

[0030] The hydraulic cylinder that causes crawling is improved by replacing it with a constant speed device.

[0031] like Figure 1 As shown, a large-diameter pipe bending machine with variable bending radius also includes... A constant speed mechanism 50 is used to drive the large-diameter tube W forward at an extremely slow and constant speed. The constant speed mechanism 50 includes a slow-rotation source 51, a straight-line conversion mechanism 52, and a moving plate 53 connected in sequence. The moving plate 53 is vertically positioned and slidably mounted on a linear track 54, which is arranged along the straight-line path L1. The tail end of the large-diameter tube abuts against the moving plate 53, and the head end passes through the heating mechanism 10 and is fixedly connected to the movable clamp 12. The slow-rotation source 51 sets the initial rotational speed V... 初 Reduced to extremely slow speed V 慢 The output converter 52 converts rotation into linear motion, and the converter 52 drives the moving plate 53 to move at a slow linear speed V. 直 Movement, 20mm / min ≤V 直 ≤200mm / minute.

[0032] The slow-speed power source 51 includes a high-speed motor 51.1, a first reducer 51.2, and a second reducer 51.3. The output shaft of the high-speed motor 51.1 is connected to the first reducer 51.2, and the first reducer 51.2 is connected in series with the second reducer 51.3, which reduces the speed of the power source 51 by a factor of N, where N≥1000. The high-speed motor 51 is a worm gear motor.

[0033] The rotary conversion 52 includes a second reduction gear 51.2 whose output shaft is connected to a synchronous rotating shaft 52 via a coupling. The synchronous main rotating shaft 52 has a main sprocket pair fixedly mounted on it, and the synchronous driven rotating shaft has a driven sprocket pair fixedly mounted on it. Chain pairs 56 are respectively fitted between the main sprocket pair and the driven sprocket pair. The moving plate 53 has symmetrically arranged lug devices 55 on both sides, and the lug devices 55 are fixedly connected to the upper chain pair 57. The slow rotational speed of the synchronous main rotating shaft 52 is converted into a slow linear movement of the upper chain pair 57 of the chain pair 56 along the axial direction OO of the large-diameter pipe W.

[0034] Taking the bending construction of a spiral welded pipe with a length of 3.6m, a diameter of Φ1200mm, and a wall thickness of 38mm as an example, it takes about 3 hours from the start to the end of the bending process. The constant speed mechanism 50 moves at a fixed slow straight-line speed V. 直 The continuous, slow, and continuous feeding without any pauses or instability is a length of time that a hydraulic cylinder system would struggle to handle. Example

[0035] Replace the pivot with an elliptical mechanism 60 to achieve elliptical bending.

[0036] like Figure 1 As shown, a large-diameter pipe bending machine with variable bending radius also includes... An elliptical mechanism 60 is used, replacing the pivot seat 23. The other end of the swing arm 21 is connected to the elliptical mechanism 60 to guide the moving chuck 21 to achieve elliptical bending. The elliptical mechanism 60 includes a bidirectional rail seat 61, a central pivot 62, and a small connecting rod 63. The bidirectional rail seat 61 includes a horizontal slide rail 64 and a vertical slide rail 65, which intersect perpendicularly at the origin O. The horizontal slider 66 is slidably mounted on the horizontal slide rail 64, and the vertical slider 67 is slidably mounted on the vertical slide rail 65. The vertical slider 65 is hinged to the tail end position 21.1 of the swing arm shaft 21, and the horizontal slider 64 is hinged to the middle section position 21.2 of the swing arm shaft 21. The central pivot 62 is fixed on the frame above the origin O. One end of the small connecting rod 67 is hinged to the central pivot 62, and the other end is hinged to the swing arm shaft 21 at the midpoint position 21.3 between the tail end position 21.1 and the middle section position 21.2.

[0037] A moldless pipe bending machine for large-diameter pipes with variable bending radius is easy to transport and install. It allows for on-site bending at the construction site, and can flexibly adjust the bending radius of circular arc bending to achieve slow constant speed feeding. It can also achieve elliptical arc bending. It is easy to use and solves the practical problems of pipe bending on site.

Claims

1. A moldless pipe bending machine for large-diameter pipes with variable bending radius, characterized in that, include Heating mechanism (10), a large-diameter tube slowly passes through the heating mechanism along a straight path (L1) to heat the passing part of the large-diameter tube to above the deformation temperature to continuously form a curved part; The swing arm mechanism (20) is used to provide bending guidance deformation force to the above-mentioned curved part. The swing arm mechanism (20) includes a swing arm shaft (21), a movable chuck (22) and a pivot seat (23). One end of the swing arm shaft (21) is fixedly connected to the movable chuck (22) and the other end is fixedly connected to the pivot seat (23). The movable chuck (22) is fixedly connected to the curved part, and the pivot seat (23) is rotatably fixed in the pivot position (C1). The diameter adjustment mechanism (30) is used to adjust the pivot position (C1) before bending operations; the diameter adjustment mechanism (30) includes a three-fixed slide rail (31) and a diameter adjustment cylinder (32), the pivot seat (23) is slidably disposed on the three-fixed slide rail (31), and the diameter adjustment cylinder (32) is fixedly connected to the pivot seat (23); A fixing mechanism (40) is used to fix the pivot seat (23) in the pivot position (C1).

2. The large-diameter pipe bending machine with variable bending radius as described in claim 1, characterized in that, The pivot seat (23) includes a seat body (25), the seat body (25) includes three guide slides (29), the three guide slides (29) are slidably supported on three fixed slide rails (31); the three fixed slide rails (31) include an integrally connected top slide rail (33) and an H-shaped steel rail (34), the two top guide slides (29) are slidably fitted on the top of the two top slide rails (33), and the bottom guide slides (29) are slidably disposed on the outer slide rail part (35) of the H-shaped steel rail (34).

3. The large-diameter pipe bending machine with variable bending radius as described in claim 2, characterized in that, The pivot seat (23) also includes a pivot part (24) and a fixed chuck (26). The pivot part (24) is located on the top of the seat body with the rotation center facing the top of the H-shaped steel rail (34). The fixed chuck (26) is integrally connected to one side of the pivot part (24). The fixed chuck (26) forms a perpendicular straight line with the axis of the pivot part (24) in opposite planes. The distance between the two axes is L = r1 + r2 + gap, where r1 is the radius of the swing arm shaft (21), r2 is the radius of the pivot part (24), and gap is the inter-axis allowance. gap < r 1 .

4. The large-diameter pipe bending machine with variable bending radius as described in claim 1, characterized in that, The fixing mechanism (40) includes multiple bolts (41) and nuts (42), with multiple bolts (41) passing through multiple through holes in the pivot seat (23) and nuts (42) screwed onto the ends of the bolts (41).

5. The large-diameter pipe bending machine with variable bending radius as described in claim 1, characterized in that, It also includes an elliptical mechanism (60), which replaces the pivot (23) to achieve elliptical bending; the elliptical mechanism (60) includes an integrally connected bidirectional rail base layer (61) and a connecting rod layer (62), the bidirectional rail base layer (61) includes a horizontal slide rail (64) and a vertical slide rail (65) that intersect perpendicularly at the central origin, the horizontal slider (66) is slidably disposed on the horizontal slide rail (64), and the vertical slider (67) is slidably disposed on the vertical slide rail (65); the connecting rod layer (62) includes a rocker arm connecting rod (63), one end of the rocker arm connecting rod (63) is hinged to the central origin; the vertical slider (67) is hinged to the tail end of the swing arm shaft (21), the horizontal slider (66) is hinged to the midpoint of the swing arm shaft (21), the other end of the rocker arm connecting rod (63) is hinged to the tail 1 / 4 position of the swing arm shaft (21), and the head end of the swing arm shaft (21) is fixedly connected to the moving part. Clamp (22).

6. The large-diameter pipe bending machine with variable bending radius as described in claim 1, characterized in that, Also includes A constant speed mechanism (50) is used to drive the large-diameter pipe W forward at an extremely slow and constant speed. The constant speed mechanism (50) includes a slow rotation source (51), a straight-line conversion (52), and a moving plate (53) connected in sequence. The moving plate (53) is vertically mounted on a straight track (54). The straight-line conversion (52) includes a synchronous main shaft and a synchronous slave shaft. A chain pair (56) is provided between the synchronous main shaft and the synchronous slave shaft. The upper chain pair (57) of the chain pair (56) is fixedly connected to the moving plate (53). The other end of the large-diameter pipe opposite to the curved part abuts against the moving plate (53).

7. The large-diameter pipe bending machine with variable bending radius as described in claim 6, characterized in that, The slow-rotating source (51) includes a high-power motor (51.1), a first decelerator (51.2), and a second decelerator (51.3). The output shaft of the high-power motor (51.1) is connected to the first decelerator (51.2), and the output shaft of the first decelerator (51.2) is connected to the second decelerator (51.3), so that the rotation speed of the slow-rotating source (51) is reduced by N times, where N is greater than or equal to one thousand.

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