Integral forming and manufacturing device for large-diameter rectangular corrugated pipe

Abstract

The invention relates to the technical field of large-diameter rectangular corrugated pipe forming, and provides an integral forming and manufacturing device for a large-diameter rectangular corrugated pipe, which is used for solving the problems of size out-of-tolerance, low efficiency and high cost caused by non-uniform forming pressure of straight edges and round corners in the prior art. The device comprises a central control mechanism which is provided with a first oil cylinder to drive synchronous or independent feeding of four sections of straight edge dies; and the four round corner control mechanisms are arranged at the four corners of the device correspondingly, each round corner control mechanism comprises a second oil cylinder and a five-petal type multi-petal forming die, and round corner forming is achieved through cooperative action of a hinge or a sliding rail. Through split control, the multi-petal die and process optimization, independent adjustment of straight edge and fillet forming pressure is achieved for the first time, the high-wave pitch precision of the corrugation is remarkably improved, the out-of-tolerance and shape correction frequency is reduced, and the method is suitable for overall efficient forming of the nuclear-power-grade large-caliber, high-wave and high-parameter rectangular corrugated pipe.

Description

Technical Field

[0001] The present invention relates to the technical field of large-diameter rectangular corrugated pipe forming, and particularly relates to an integral forming manufacturing device for large-diameter rectangular corrugated pipes. Background Art

[0002] This equipment is used to manufacture special large-diameter rectangular corrugated pipes that meet nuclear power levels, which are characterized by high wave height parameters, rounded corners, multiple layers (number of layers ≥ 2), integral forming (only 1 weld per layer), a rectangular cross-sectional shape, and straight edge dimensions exceeding 1.5 m. The existing rectangular corrugated pipe forming equipment uses a displacement control forming method during the forming process, which consists of four straight edge segments and four corner molds. The principle is to push the surrounding molds through a central taper to press the corrugated pipe blank into the mold to form corrugations.

[0003] When the existing displacement control pressure forming method is used to integrally form a rectangular cross-sectional corrugated pipe, due to the large difference in the pressure required for forming the rounded corners and the straight edges, as the requirements for wave height parameters continue to increase, the dimensional differences between the formed corners and straight edges also continue to increase, limiting the further increase of wave height parameters. When forming corrugated pipes with high wave height dimensions, it is necessary to frequently replace multiple sets of progressive forming die plates to meet the forming requirements, which not only increases the labor and time costs but also further increases the manufacturing cost. At the same time, the straight edges and rounded corners of the corrugated pipe move synchronously, the structure and function of the rounded corner part are single, and there are large deviations in the waveform during the forming process and repeated shape correction is required. Summary of the Invention

[0004] The present invention discloses an integral forming manufacturing device for large-diameter rectangular corrugated pipes. Aiming at the problem of large deviations in the waveform and the need for repeated shape correction during the forming process of multi-layer rectangular corrugated pipes, by changing the structure of the forming equipment and optimizing the forming process, the separate control of the rounded corner and straight edge forming is realized for the first time, thereby further improving the forming quality and efficiency of the product.

[0005] The main problems solved by the present invention are as follows:

[0006] The separate control of the straight edge and rounded corner forming ensures the smooth transition between the rounded corner and the straight edge and the accuracy of the dimensions, improving the forming quality of the product;

[0007] The mold for the rounded corner part adopts a multi-petal structure, which greatly realizes the smooth transition of the rounded corner and the accuracy and reliability of the wave height and wave pitch of the rounded corner.

[0008] Aiming at the problems of large waveform tolerances and the need for repeated shape correction during the forming process of multi-layer rectangular corrugated pipes, by changing the structure of the forming equipment and optimizing the forming process, on the basis of displacement-controlled forming, multi-mode plates are used at the four corners for corner forming. The corners can displace a longer distance and form larger sizes. Moreover, during the forming process, due to the pressure forming of the multi-mode plates, the force on the rounded corners is relatively balanced, controlling the dimensional accuracy of the rounded corners. This greatly reduces the manufacturing cost and the requirements for auxiliary equipment, thereby further improving the forming quality and efficiency of the product.

[0009] At the same time, the device can also achieve separate control of the straight edges and rounded corners, ensuring smooth transitions between the rounded corners and the straight edges. The difference between the formed corners and the straight edges is only controlled by the displacement of the die propulsion, and it can be applied to the overall forming of corrugated pipes with higher wave height parameters.

[0010] The present invention provides an overall forming manufacturing device for large-diameter rectangular corrugated pipes, including:

[0011] A central control mechanism, equipped with a first oil cylinder, for driving the synchronous or independent feeding of the four-section straight-edge dies;

[0012] Four corner control mechanisms, respectively arranged at the four corners of the device. Each corner control mechanism includes a second oil cylinder and a multi-petal forming die connected thereto, for realizing independent feeding control of the rounded corner part;

[0013] Among them, the straight-edge die and the rounded corner die are separately arranged, and the independent adjustment of the forming pressure of the straight edge and the rounded corner is realized through separate control.

[0014] Furthermore, for the overall forming manufacturing device for large-diameter rectangular corrugated pipes of the present invention, the multi-petal forming die is of a five-petal structure. Each petal die is connected by hinges or slides and acts in coordination under the drive of the second oil cylinder to form a smoothly transitioning rounded corner corrugation.

[0015] Furthermore, for the overall forming manufacturing device for large-diameter rectangular corrugated pipes of the present invention, the feeding displacement of the straight-edge die is controlled by the stroke of the first oil cylinder, and the feeding amounts of the four-section straight-edge dies can be adjusted separately or synchronously to meet the forming requirements of different wave height parameters.

[0016] Furthermore, for the overall forming manufacturing device for large-diameter rectangular corrugated pipes of the present invention, the stroke of the second oil cylinder of the corner control mechanism is greater than the stroke of the first oil cylinder of the straight-edge control mechanism to realize larger-size displacement forming of the rounded corner part.

[0017] Furthermore, for the overall forming manufacturing device for large-diameter rectangular corrugated pipes of the present invention, it further includes an electrical control unit for real-time monitoring and adjusting the pressure and displacement parameters of the first oil cylinder and the second oil cylinder to ensure the coordination and dimensional accuracy of the straight-edge and rounded corner forming processes.

[0018] Furthermore, in the large-diameter rectangular corrugated pipe integral forming manufacturing device of the present invention, each flap of the multi-flap forming die is provided with a pressure sensor, which is used to feedback the force data during the fillet forming process, and adjust the feed amount of the second oil cylinder through closed-loop control.

[0019] Furthermore, in the large-diameter rectangular corrugated pipe integral forming manufacturing device of the present invention, the inner surfaces of the straight-edge die and the fillet die are provided with profiled corrugated structures, and their shapes match the corrugation parameters of the target corrugated pipe, so as to reduce the out-of-tolerance rate after forming.

[0020] Furthermore, the large-diameter rectangular corrugated pipe integral forming manufacturing device of the present invention further includes a square-supporting tooling and a straightening mechanism, wherein:

[0021] The square-supporting tooling is used to expand the circular pipe blank into a rectangular cross-section and position the nested and staggered joints of multiple layers of pipe blanks;

[0022] The straightening mechanism includes a driving wheel, a driven wheel and a supporting wheel, and rotates the pipe blank through linear friction to eliminate the residual stress after forming.

[0023] Advantages of the present invention:

[0024] The present invention provides a large-diameter rectangular corrugated pipe integral forming manufacturing device. By changing the structure of the forming equipment and optimizing the forming process, the separate control of fillet and straight-edge forming is realized for the first time. At the same time, the design of four fillet multi-mode pieces makes the forming more accurate and improves the forming quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, for those of ordinary skill in the art, other drawings can also be obtained according to the drawings without creative efforts.

[0026] Figure 1 It is a schematic diagram of the bulging principle provided by an embodiment of the present invention.

[0027] Figure 2 It is a schematic top view of the device provided by an embodiment of the present invention.

[0028] Figure 3 It is a schematic diagram of the whole forming machine and the corner mechanism provided by an embodiment of the present invention.

[0029] BRIEF DESCRIPTION OF THE DRAWINGS: 1. Straight-edge forming mechanism, 2. Oil cylinder, 3. Corner forming mechanism. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention. The following will describe in detail the technical solutions provided by each embodiment of the present invention with reference to the drawings.

[0031] To better understand the objectives of the present invention, the present invention will be further described in detail below.

[0032] An integral forming manufacturing device for large-diameter rectangular corrugated pipes, comprising:

[0033] The structure of an integral forming manufacturing device for large-diameter rectangular corrugated pipes is as shown in the attached drawings. The main contents of the present invention are as follows:

[0034] Five separate oil cylinders are provided to achieve separate control of the straight edge and rounded corner forming and precise feeding of the mold, ensuring smooth transition between the rounded corner and the straight edge and dimensional accuracy, and improving the forming quality of the product.

[0035] For the structure of the rounded corner part, a multi-petal mold is adopted, which greatly realizes the smooth transition of the rounded corner and the accuracy and reliability of the wave height and wave pitch of the rounded corner.

[0036] Embodiment requirements: The rectangular corrugated pipe with rounded corners is composed of three layers of pipe blanks and has a total of 3 corrugations.

[0037] The specific steps are as follows:

[0038] (1) Select materials, and select the first-layer, second-layer, and third-layer coils.

[0039] (2) Cut the materials. Use a slitting machine to slit the first-layer, second-layer, and third-layer coils into flat plates, and mark the corresponding dimensions on each coil.

[0040] (3) Cut the fine materials. Cut the coils according to the corresponding dimension marks.

[0041] (4) Remove burrs, and clean the burrs on the surface to be welded and the adjacent areas.

[0042] (5) Draw lines at the bending positions. Draw bending lines at the required bending positions on the third coil.

[0043] (6) Supporting the tube: the first layer coil, the second layer coil and the third layer coil are respectively connected at both ends to complete the longitudinal seam welding to form a round tube billet, and the surface of the tube billet is checked to confirm that there are no scratches, bumps, pits and other defects on the surface. The tube billet is cleaned and fitted from the inside to the outside. When fitting the tube billet, the longitudinal weld of the second layer of the tube billet is used as the center line, and the longitudinal welds of the first and third layers are staggered to both sides. After fitting, the corresponding bending line is used to support the square tool to support the round tube billet into a rectangular tube billet;

[0044] (7) Welding process: After the rectangular tube is squared, the upper and lower ports are welded and fixed by argon arc welding. After welding, the inner and outer surfaces of the tube are cleaned, and welding slag, dirt, rust, etc. are not allowed.

[0045] (8) Bellows forming: confirm the required single wave expansion length and draw the center line mark of 3 corrugations, hoist the tube blank into the forming die, and use the bracket to support the tube blank (attached Figure 1 ), start the hydraulic power, use the oil cylinder to push the 8-direction internal expansion mold to the appropriate position and then stop, complete the expansion of the first corrugation, lift the tube blank to the center mark position of the second corrugation to expand the second corrugation, take the tube blank after the third corrugation is expanded;

[0046] (9) Bellows orthopedic treatment: hoist the pressed tube blank, place it between the orthopedic active wheel and the passive wheel, use the support wheel to hold the entire tube blank, use the linear friction between the wheel and the tube blank to rotate the tube blank, and remove it after the orthopedic treatment is completed;

[0047] (10) Cut straight edges. Draw lines with a marker pen on the two straight edge sections of the bellows. Use a plasma cutter to cut the straight edges according to the drawn line positions. Use a grinder to grind the two ends of the bellows flush after cutting the straight edges to complete the final bellows molding and manufacturing.

[0048] The present invention provides a large-diameter rectangular corrugated pipe integral forming manufacturing device, wherein an oil cylinder is arranged in the center of the mechanism and connected with four straight-side molds to control the feeding distances of the four straight-side molds; four oil cylinders are arranged around the mechanism and connected with four rounded-corner molds to control the feeding distances of the four rounded-corner molds individually.

[0049] Each rounded corner is provided with a 5-petal forming mold, which realizes the smooth transition of the rounded corner and the accuracy and reliability of the wave height and wave distance of the rounded corner to a great extent.

[0050] The invention patent discloses a large-caliber rectangular corrugated pipe integral forming manufacturing device, including a cylinder, a forming mold, a connector, and electrical and control equipment, etc. The rounded corner and straight edge forming are controlled separately, and the rounded corner part adopts a multi-petal mold design, which improves the forming quality and forming efficiency of the multi-layer rectangular corrugated pipe product.

[0051] The specific analysis of the technical pain points solved by the technical solution of the present invention is as follows:

[0052] Correspondence between pain points of the prior art and solutions of the present invention:

[0053] Pain point: The forming pressures of the straight edge and the rounded corner are quite different, resulting in out-of-tolerance dimensions:

[0054] Existing problem: In traditional equipment, the straight edge and the rounded corner are synchronously controlled. However, the pressure required for the rounded corner forming is much higher than that of the straight edge, resulting in significant dimensional differences between the corner and the straight edge after forming, which limits the improvement of the wave height parameter.

[0055] Solution:

[0056] Split control structure: A central control mechanism (a four-section straight-edge die driven by a first oil cylinder) and four independent rounded-corner control mechanisms (a multi-lobe die driven by a second oil cylinder) are provided to achieve independent adjustment of the forming pressures of the straight edge and the rounded corner (Claim 1).

[0057] Differentiated design of the oil cylinder stroke: The stroke of the second oil cylinder of the rounded-corner control mechanism is greater than that of the first oil cylinder of the straight-edge control mechanism (Claim 4), enabling the rounded-corner die to displace further to meet the forming requirements of high wave height.

[0058] Technical effect: The forming pressures and displacement amounts of the straight edge and the rounded corner are independently controlled, reducing dimensional differences and increasing the upper limit of the wave height parameter.

[0059] Pain point: The forming accuracy of the rounded corner is low, and repeated shape correction is required.

[0060] Existing problem: The structure of the rounded-corner die is single, and the force is unevenly distributed, resulting in out-of-tolerance wave height and wave pitch of the rounded-corner corrugation.

[0061] Solution:

[0062] Multi-lobe die design: The rounded-corner die adopts a five-lobe structure (Claim 2), and each lobe acts cooperatively through hinges or slide rails to make the force on the rounded corner evenly distributed.

[0063] Contour-following corrugation structure: The inner surface of the die is provided with a contour-following structure matching the target corrugation (Claim 7) to reduce out-of-tolerance after forming.

[0064] Technical effect: The smooth transition and dimensional accuracy of the rounded-corner corrugation are significantly improved, reducing the number of shape correction times.

[0065] Pain point: Frequent replacement of die pieces, high cost and low efficiency:

[0066] Existing problem: Multiple sets of progressive die pieces are required for high-wave-height forming, resulting in increased labor and time costs.

[0067] Solution:

[0068] Adjustable cylinder stroke: The feed rate of the straight edge mold can be adjusted individually or simultaneously (claim 3) to adapt to different wave height parameters.

[0069] Closed-loop control technology: The pressure sensor provides real-time feedback of fillet force data (claim 6) and dynamically adjusts the cylinder feed rate.

[0070] Technical effect: A single set of molds can cover a wider molding range, reduce the frequency of mold replacement, and reduce costs.

[0071] Pain point: It is difficult to position the staggered seams of multi-layer tube blanks:

[0072] Existing problem: When the multi-layer tube blanks are fitted together, the weld misalignment accuracy is insufficient, which affects the forming quality.

[0073] Solution:

[0074] Square support tooling: positioning the multi-layer tube blanks to fit the staggered seams (claim 8) and ensure that the welds are staggered according to the preset positions.

[0075] Technical effect: Improve the fitting accuracy and avoid forming defects caused by interlayer stress concentration.

[0076] Pain point: residual stress after molding causes deformation

[0077] Existing problem: The corrugated pipe needs to be manually corrected after forming, which is inefficient.

[0078] Solution:

[0079] Correction mechanism: The tube blank is rotated by linear friction of the driving wheel, the passive wheel and the supporting wheel (claim 8), thereby automatically eliminating residual stress.

[0080] Technical effect: Realize automated correction, improve efficiency and ensure the straightness of finished products.

[0081] The core innovation of the technical solution:

[0082] Split control and coordinated regulation:

[0083] The straight edge and the rounded corner are controlled independently, and the pressure and displacement parameters are monitored in real time in combination with the electrical control unit (claim 5), so as to ensure the coordination of the forming process of the two and solve the size mismatch problem caused by traditional synchronous control.

[0084] Mechanical optimization of multi-petal molds:

[0085] The five-petal mold disperses the concentrated load into multiple points of balanced pressure (attached to the instruction manual) Figure 2 ) to avoid excessive local stress and improve the rounded corner forming accuracy.

[0086] Process chain integration:

[0087] Integrate processes such as bracing, forming, and orthopedic correction into the same device (Steps 6-10 of the specific implementation method), reduce intermediate links through process optimization, and improve overall efficiency.

Claims

1. A large-caliber rectangular corrugated pipe integral forming manufacturing device, characterized in that: include: The central control mechanism is equipped with a first oil cylinder for driving the synchronous or independent feeding of the four-section straight-edge mold; Four fillet control mechanisms are respectively arranged at the four corners of the device, each of which includes a second oil cylinder and a multi-petal forming die connected thereto, for realizing independent feed control of the fillet part; The straight edge mould and the rounded corner mould are separately arranged, and the independent adjustment of the straight edge and rounded corner forming pressures is achieved through separate control.

2. The large-diameter rectangular corrugated pipe integral forming manufacturing device according to claim 1 is characterized in that: The multi-petal forming mold is a five-petal structure, and each petal mold is connected by a hinge or a slide rail, and moves in coordination under the drive of the second oil cylinder to form rounded corner corrugations with smooth transition.

3. The large-diameter rectangular corrugated pipe integral forming manufacturing device according to claim 1 is characterized in that: The feed displacement of the straight-edge mold is controlled by the stroke of the first oil cylinder, and the feed amounts of the four-section straight-edge molds can be adjusted individually or synchronously to meet the molding requirements of different wave height parameters.

4. The large-diameter rectangular corrugated pipe integral forming manufacturing device according to claim 1 is characterized in that: The stroke of the second oil cylinder of the rounded corner control mechanism is greater than the stroke of the first oil cylinder of the straight edge control mechanism, so as to achieve displacement forming of a larger size of the rounded corner part.

5. The large-diameter rectangular corrugated pipe integral forming manufacturing device according to claim 1 is characterized in that: It also includes an electrical control unit for real-time monitoring and adjusting the pressure and displacement parameters of the first cylinder and the second cylinder to ensure the coordination and dimensional accuracy of the straight edge and rounded corner forming processes.

6. The large-diameter rectangular corrugated pipe integral forming manufacturing device according to claim 1 is characterized in that: Each petal of the multi-petal forming mold is provided with a pressure sensor for feeding back force data during the rounded corner forming process and adjusting the feed amount of the second oil cylinder through closed-loop control.

7. The large-diameter rectangular corrugated pipe integral forming manufacturing device according to claim 1 is characterized in that: The inner surfaces of the straight-edge mold and the rounded-corner mold are provided with a contoured corrugated structure, the shape of which matches the corrugation parameters of the target corrugated pipe to reduce the excess rate after forming.

8. The large-diameter rectangular corrugated pipe integral forming manufacturing device according to any one of claims 1 to 7, characterized in that: Also included are bracing and orthopedic devices, including: The square support tool is used to support the round tube blank to a rectangular cross section and to locate the overlapping and staggered seams of the multi-layer tube blank; The orthopedic mechanism comprises a driving wheel, a driven wheel and a supporting wheel, and rotates the tube blank through linear friction to eliminate residual stress after forming.

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