Large rotary type large-width longitudinal welded pipe forming machine and operation method

Abstract

The invention relates to a large rotary type large-width longitudinal welded pipe forming machine and an operation method, the large rotary type large-width longitudinal welded pipe forming machine comprises an upper die assembly and a lower die assembly which are oppositely arranged, a pit is formed in the lower die assembly, a pre-bent plate is placed in the pit, the upper die assembly presses back and forth in the vertical direction, and the pre-bent plate is formed into a steel pipe; the upper die assembly structurally comprises a long die handle, a plurality of transition dies distributed at intervals are installed at the lower end of the long die handle in the whole length direction, an arc T-shaped block is installed between every two adjacent transition dies in a matched mode, a movable arc rotating plate is installed at the bottom of each transition die and the bottom of each arc T-shaped block at the same time, and a wide upper die is installed at the bottom of each arc rotating plate. Through redesign of the upper die assembly, the arc rotating plate is uniquely designed, the width of the upper die is increased, the bending forming frequency is reduced, the working efficiency is improved, and the forming machining requirement of the large-diameter steel pipe is met.

Description

Technical Field

[0001] This invention relates to the field of steel pipe processing technology, and in particular to a large-scale rotary wide-width straight seam welded pipe forming machine and its operating method. Background Technology

[0002] Currently, due to the successful development of the deep-sea drilling platform 981, the demand for large-diameter, thick-walled, high-grade steel oil and gas pipes is increasing. Forming machines represent an ideal, flexible new process and equipment for producing large straight seam welded pipes, with broad market prospects. However, in existing technologies, the forming of large-diameter (above 711mm) steel pipes suffers from low efficiency due to the narrow upper die, short effective arc length per forming cycle, and numerous bending operations, impacting the production line's overall efficiency. Summary of the Invention

[0003] In response to the shortcomings of the existing production technology, the applicant provides a large-scale rotary wide-seam welded pipe forming machine and its operation method, which uniquely designs an arc rotating plate, increases the width of the upper die, reduces the number of bending and forming operations, and improves work efficiency.

[0004] The technical solution adopted in this invention is as follows: A large-scale rotary wide-width straight seam welded pipe forming machine includes an upper mold assembly and a lower mold assembly arranged opposite to each other. The lower mold assembly is provided with a recess, and a pre-bent plate is placed inside the recess. The upper mold assembly presses back and forth in the vertical direction to form the pre-bent plate into a steel pipe. The upper mold assembly has the following structure: it includes a long mold shank, with multiple spaced transition molds installed along the entire length of the lower end of the long mold shank, and an arc T-shaped block installed between two adjacent transition molds. A movable arc rotating plate is installed at the bottom of the transition molds and the arc T-shaped block, and a wide upper mold is installed at the bottom of the arc rotating plate.

[0005] Its further technical solution lies in: Hard limit blocks are installed on both sides of a single transition mold via fasteners.

[0006] The structure of a single transition mold is as follows: it includes an arc-shaped module, the bottom concave arc of which is completely fitted with the arc rotating plate, a U-shaped module is provided on the top surface of the arc-shaped module, a long mold shank is inserted into the U-shaped module, and multiple round holes and long slots are opened on the side of the U-shaped module.

[0007] The upper mold assembly can rotate within the range of 0-7.5 degrees.

[0008] The width of the upper mold is 350mm-600mm.

[0009] After the contact surfaces of the arc-shaped rotating plate and the wide upper die are in full contact, the wide upper die and the arc-shaped rotating plate are pressed together by the wide die pressing block.

[0010] The wide upper mold has an integral structure.

[0011] The bottom surface of the wide upper mold has an arc-shaped structure.

[0012] Spring baffles are also installed on both sides between two adjacent transition molds.

[0013] An operating method for a large-scale rotary wide-width straight seam welded pipe forming machine includes the following operating procedures: Step 1: Prepare a piece of board and pre-bend it; Step 2: Place the pre-bent sheet material into the recess of the lower mold assembly; Step 3: The upper mold assembly is pressed down under the action of external power, and the wide upper mold directly contacts the pre-bent plate to perform the bending work. Step 4: Repeat step 3, bending 10-15 times; Step 5: Bend the pre-bent sheet metal into a "C" shaped steel pipe; Step 6: Done.

[0014] The beneficial effects of this invention are as follows: This invention features a compact and reasonable structure, and is easy to operate. Through the redesign of the upper mold assembly, a unique arc rotating plate is designed, which increases the width of the upper mold, reduces the number of bending and forming operations, improves work efficiency, and meets the forming and processing requirements of large-diameter steel pipes.

[0015] This invention is mainly used in steel pipe production and processing. It has multiple functions such as automatic feeding, automatic material support, bending and forming, rotating tube blank, automatic material discharge, and seam straightening. It can continuously and efficiently produce open tube blanks for large straight seam pipes. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention.

[0017] Figure 2 This is a schematic diagram of the departmental structure of the present invention.

[0018] Figure 3 This is a schematic diagram of the upper mold assembly of the present invention.

[0019] Figure 4 for Figure 3 Exploded view.

[0020] Figure 5 for Figure 3 A partial view (zoomed in).

[0021] Figure 6 This is the front view of the upper mold component of the present invention.

[0022] Figure 7 for Figure 6 Full sectional view along section AA.

[0023] Figure 8 for Figure 6 Full sectional view along section BB.

[0024] Figure 9 This is a diagram illustrating the working state of the present invention.

[0025] Figure 10 This is a schematic diagram of the transition mode of the present invention.

[0026] Figure 11 This is a schematic diagram of the structure of the arc-shaped T-block of the present invention.

[0027] Among them: 1. Upper mold assembly; 2. Lower mold assembly; 3. Pre-bent sheet material; 101. Long mold shank; 102. Transition mold; 103. Arc T-shaped mold; 104. Arc rotating plate; 105. Wide mold pressing block; 106. Wide upper mold; 107. Hard limit block; 108. Spring baffle; 1021, U-shaped module; 1022, round hole; 1023, arc-shaped module; 1024, long strip groove. Detailed Implementation

[0028] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0029] like Figures 1-11 As shown, the large-scale rotary wide-width straight seam welded pipe forming machine of this embodiment includes an upper mold assembly 1 and a lower mold assembly 2 arranged opposite to each other. The lower mold assembly 2 is provided with a recess, and a pre-bent plate 3 is placed inside the recess. The upper mold assembly 1 presses back and forth in the vertical direction to form the pre-bent plate 3 into a steel pipe. The upper mold assembly 1 has the following structure: it includes a long mold shank 101, and a number of spaced transition molds 102 are installed along the entire length of the lower end of the long mold shank 101. An arc T-shaped block 103 is installed between two adjacent transition molds 102. A movable arc rotating plate 104 is installed at the bottom of the transition molds 102 and the arc T-shaped block 103. A wide upper mold 106 is installed at the bottom of the arc rotating plate 104.

[0030] Hard limit blocks 107 are installed on both outer sides of a single transition mold 102 by fasteners.

[0031] The structure of a single transition mold 102 is as follows: it includes an arc-shaped module 1023, the bottom concave arc of the arc-shaped module 1023 is completely fitted with the arc rotating plate 104, the top surface of the arc-shaped module 1023 is provided with a U-shaped module 1021, a long mold shank 101 is inserted into the U-shaped module 1021, and the side of the U-shaped module 1021 has multiple round holes 1022 and long strip grooves 1024.

[0032] The upper mold assembly 1 can rotate within the range of 0-7.5 degrees.

[0033] The width of the upper die 106 is 350mm-600mm.

[0034] After the contact surfaces of the arc rotating plate 104 and the wide upper mold 106 are in full contact, the wide upper mold 106 and the arc rotating plate 104 are pressed together by the wide mold pressing block 105.

[0035] The wide upper mold 106 has a one-piece structure.

[0036] The bottom surface of the wide upper mold 106 has an arc-shaped structure.

[0037] Spring baffles 108 are also installed on both sides between two adjacent transition molds 102.

[0038] The operation method of the large-scale rotary wide-width straight seam welded pipe forming machine in this embodiment includes the following operation process: Step 1: Prepare a piece of board and pre-bend it; Step 2: Place the pre-bent plate 3 into the recess of the lower mold assembly 2; Step 3: The upper mold assembly 1 is pressed down under the action of external power, and the wide upper mold 106 directly contacts the pre-bent plate 3 to perform bending work on the pre-bent plate 3. Step 4: Repeat step 3, bending 10-15 times; Step 5: Bend the pre-bent sheet metal into a "C" shaped steel pipe by bending it three times; Step 6: Done.

[0039] This invention features a long mold shank 101, with a transition mold 102 mounted along its entire lower length. A movable arc-shaped rotating plate 104 is mounted at the bottom of the transition mold 102. The arc-shaped rotating plate 104 is connected to the upper mold assembly 1 of the molding machine. The upper mold assembly 1 of the molding machine can rotate within a range of 0-7.5 degrees. An arc-shaped T-block 103 is connected to the arc-shaped rotating plate 104 by screws. The arc surface of the arc-shaped T-block 103 is in clearance fit with the arc surface of the transition mold 102, and rotates together with the arc-shaped rotating plate 104 within the arc surface of the transition mold 102. After the arc-shaped rotating plate 104 and the wide upper mold 106 are fully in contact, the wide upper mold 106 and the arc-shaped rotating plate 104 are pressed together by a wide mold pressing block 105.

[0040] The hard limit block 107 acts as a hard limit for the upper mold assembly 1 of the molding machine, allowing it to rotate within the required range.

[0041] In the production process of straight seam steel pipes, the plate is required to be pre-bent before forming. The cutting points of the plate at the lower die are at different positions on both sides, resulting in an asymmetrical bending during forming. If the upper die width is increased, the upper die will bear a larger bending moment under sufficiently large bending force, increasing the stress and strain at the contact point between the die shank and the upper die, thus damaging the die shank and affecting the accuracy of the formed steel pipe. Using the upper die assembly 1 in this embodiment, due to the addition of the arc rotating plate 104, the entire upper die can rotate within a range of 0-7.5 degrees, ensuring symmetrical bending for each bend. For pipe diameters ranging from 711mm to 1626mm, the corresponding upper die width range is 350mm to 600mm (e.g., ...). Figure 9 As shown in the example, the width of the upper die in this embodiment is 500mm, while the maximum width of the upper die in the prior art is 300mm. The effective arc length of the forming increases with each bend, the number of bending and forming operations is reduced, and the bending efficiency is greatly improved.

[0042] Comparison of the working principles of this invention with existing bending forming machines: See Figure 9 When the pre-bent sheet metal 3 is placed on the lower die assembly 2 of the forming machine and pressed to the required radius, the upper die width is increased. With sufficient bending force, the upper die of the rotary wide-width forming machine incorporates an arc-shaped rotating plate 104 to ensure symmetrical bending each time, increasing the effective arc length of each forming and reducing the number of bends. If the upper die width is increased, the upper die bears a larger bending moment, increasing the stress and strain at the contact point between the die handle and the upper die, which can severely damage the machine frame and affect the accuracy of the bent steel pipe. In actual production, with a diameter of 1422mm, a plate thickness of 25.7mm, and material X70, this embodiment requires only 15 bends to form a "C" shaped steel pipe. However, using existing bending methods, at least 21 or more bends are needed to achieve the required result. Especially for large-diameter steel pipes and thick plates, the reduced number of bends significantly improves bending efficiency, laying a solid foundation for improving the overall efficiency of the production line.

[0043] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A large-scale rotary wide-width straight seam welded pipe forming machine, characterized in that: It includes an upper mold assembly (1) and a lower mold assembly (2) arranged opposite to each other. The lower mold assembly (2) is provided with a recess, and a pre-bent plate (3) is placed inside the recess. The upper mold assembly (1) presses back and forth in the vertical direction to form the pre-bent plate (3) into a steel pipe. The upper mold assembly (1) has the following structure: it includes a long mold shank (101), and a number of spaced transition molds (102) are installed along the entire length of the lower end of the long mold shank (101). An arc T-shaped block (103) is installed between two adjacent transition molds (102). A movable arc rotating plate (104) is installed at the bottom of the transition mold (102) and the arc T-shaped block (103). A wide upper mold (106) is installed at the bottom of the arc rotating plate (104).

2. The large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: Hard limit blocks (107) are installed on both outer sides of a single transition mold (102) by fasteners.

3. The large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: The structure of a single transition mold (102) is as follows: it includes an arc-shaped module (1023), the bottom concave arc of the arc-shaped module (1023) is completely fitted with the arc rotating plate (104), the top surface of the arc-shaped module (1023) is provided with a U-shaped module (1021), a long mold shank (101) is inserted into the U-shaped module (1021), and the side of the U-shaped module (1021) has multiple round holes (1022) and long strip grooves (1024).

4. The large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: The upper mold assembly (1) rotates within the range of 0-7.5 degrees.

5. A large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: The width of the wide upper mold (106) is 350mm-600mm.

6. A large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: After the contact surfaces of the circular arc rotating plate (104) and the wide upper mold (106) are in full contact, the wide upper mold (106) and the circular arc rotating plate (104) are pressed together by the wide mold pressing block (105).

7. A large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: The wide upper mold (106) has an integral structure.

8. A large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: The bottom surface of the wide upper mold (106) has an arc-shaped structure.

9. A large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: Spring baffles (108) are also installed on both sides between two adjacent transition molds (102).

10. An operating method for a large-scale rotary wide-width straight seam welded pipe forming machine as described in claim 1, characterized in that: The following procedures are included: Step 1: Prepare a piece of board and pre-bend it; Step 2: Place the pre-bent plate (3) into the recess of the lower mold assembly (2); Step 3: The upper mold assembly (1) is pressed down under the action of external power, and the wide upper mold (106) directly contacts the pre-bent plate (3) to perform bending work on the pre-bent plate (3); Step 4: Repeat step 3, bending 10-15 times; Step 5: The pre-bent sheet metal (3) is bent into a "C" shaped steel pipe; Step 6: Done.

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