Special-shaped head of large oil tank and manufacturing method thereof

Abstract

The application relates to a large oil tank special-shaped head and a manufacturing method thereof, and comprises the following steps: the special-shaped head comprises a curved panel and a reinforcing plate fixed to the inner side of the curved panel, a three-dimensional modeling diagram of the curved panel is unfolded into a plane, and a plan view of the curved panel is obtained; according to the plan view, a plate material raw material is cut into a required shape and size by using a plasma cutting machine, and a planar plate material of the curved panel is obtained; and the planar plate material is gradually pushed into a bending machine for bending treatment, and a curved blank plate is obtained; the reinforcing plate is welded and fixed to the inner side of the curved blank plate, so that a head blank is obtained, the head blank is fixed on a solid mold until the shape of the head blank is solidified; and the head blank after the shape is solidified is transported to an edge rolling machine, and an arc-shaped flange arranged towards the inner side is rolled out from the periphery of the curved blank plate. The manufacturing method does not need punching die equipment which is very large in size and expensive, and is beneficial to low-cost, high-efficiency and accurate production of the large oil tank special-shaped head.

Description

Technical Field

[0001] This application relates to the field of large oil tank manufacturing technology, and in particular to a large oil tank irregular-shaped head and its manufacturing method. Background Technology

[0002] With the rapid development of my country's industry, domestic demand for petroleum is increasing year by year, and the transportation of various oil products plays an increasingly important role in heavy industrial production. The market demand for various large oil tank trucks is growing, and the production of large oil tank trucks has a very broad development prospect.

[0003] For example, Chinese patent application number CN202022549869.5 discloses an oil tank end cap, including a main body and an oil tank opening. A fixing strip is fixedly connected to the outer wall of the oil tank opening. Multiple movable grooves are opened on the outer wall of the main body. Limiting grooves are opened at the bottom of the inner wall of the multiple movable grooves. Multiple fixing blocks are fixedly connected to the outer wall of the main body. Through holes are opened on the sides of the multiple fixing blocks. A fixing shaft is inserted between adjacent fixing blocks. Limiting plates are fixedly connected to one side of the multiple movable plates. Pressure plates are fixedly connected to the top of the multiple limiting plates near the oil tank opening.

[0004] For example, Chinese patent application number CN201920719959.9 discloses a high-pressure end cap for oil tanks, including an outer shell, the outer shell being elliptical in shape, a sealing opening at the left end of the outer shell, an internal thread at the inner ring of the sealing opening, and a rotating ring fitted onto the outer surface of the outer shell.

[0005] As can be seen, almost all common oil tank heads are standard elliptical spherical bowl-shaped or dish-shaped structures. When making these standard heads, the sheet metal needs to be cut into a standard circular shape first, and then the circular sheet metal is stamped into a standard bowl-shaped or dish-shaped structure using a stamping and die-forming method.

[0006] Regarding the aforementioned related technologies, the inventors believe that the following defects exist: Since some large oil tanks may be around 3 meters in size, and the processing size of common small stamping equipment and corresponding molds is limited, in order to increase the processing stroke and adapt to the production of such large oil tank heads, it is necessary to customize very large and expensive stamping mold-making equipment, which is not conducive to the low-cost, efficient and precise production of large oil tank heads. Summary of the Invention

[0007] This application provides a large oil tank irregular-shaped head and its manufacturing method to improve the following technical problems:

[0008] In the first aspect, this application provides a method for manufacturing a large oil tank irregular-shaped head, adopting the following technical solution: A method for manufacturing a large, irregularly shaped end cap for an oil tank includes the following steps: Step 1: Create a 3D model of the irregular head according to the preset size and shape. The irregular head includes a curved panel and a reinforcing plate fixed on the inner side of the curved panel. Unfold the 3D model of the curved panel into a plane and obtain a planar view of the curved panel. Step 2: According to the plan, use a plasma cutter to cut the raw material into the required shape and size to obtain a flat panel of curved panel; Step 3: Adjust the processing parameters of the rolling machine according to the design dimensions of the curved panel, and gradually push the flat plate into the rolling machine for bending to obtain a curved blank plate with the corresponding curvature; at the same time, according to the design dimensions of the reinforcing plate, cut, punch and / or bend the plate material to obtain the reinforcing plate. One side of the reinforcing plate has an arc edge, and the curvature of the arc edge is consistent with the curvature of the curved blank plate. Step 4: Join and weld the curved edge of the reinforcing plate to the inner side of the curved blank to obtain the head blank; then customize a solidification mold that matches the shape of the head blank, place the head blank in the solidification mold for pressure holding and shaping until the shape of the head blank is stable and solidified. Step 5: Transport the solidified head blank to the spinning machine, and spin an arc-shaped flange around the perimeter of the curved blank plate, facing inward, to obtain a large oil tank irregular head.

[0009] In one feasible technical solution of this application, step six is ​​also included: polishing and grinding the outer periphery and weld points of the large oil tank's irregularly shaped head.

[0010] In one feasible technical solution of this application, in step three, the processing parameters of the rolling machine include: parallelism between the upper and lower rollers, width and thickness of the sheet material, material of the sheet material, target diameter of the roll, clamping force between the upper and lower rollers, rolling speed, single pressing amount and number of pressing passes, and preheating temperature.

[0011] In one feasible technical solution of this application, in step four, positioning marks are set on the inner side of the curved blank plate according to the design position, and the arc edge of the reinforcing plate is aligned with the positioning marks before welding and fixing the arc edge.

[0012] Secondly, this application provides a large oil tank irregular-shaped head, which adopts the following technical solution: A large oil tank irregular-shaped head is manufactured by the above-mentioned method, wherein the large oil tank irregular-shaped head is a stainless steel part.

[0013] In one feasible technical solution of this application, the large oil tank irregular head includes a curved panel and multiple reinforcing plates. The outer periphery of the curved panel has an arc structure and is integrally formed with an arc-shaped flange. The horizontal width of the curved panel is greater than its vertical height. The reinforcing plates are arranged horizontally, and the multiple reinforcing plates are arranged vertically at intervals.

[0014] In one feasible technical solution of this application, the inner side of the reinforcing plate is provided with an arc-shaped edge, the outer side of the reinforcing plate is provided with a vertical folded edge, and the reinforcing plate also has a plurality of weight-reducing holes.

[0015] In one feasible technical solution of this application, the reinforcing plate is provided in two parts, wherein the vertical folded edge of the upper reinforcing plate is arranged toward the top of the curved panel, and the vertical folded edge of the lower reinforcing plate is arranged toward the bottom of the curved panel.

[0016] In one feasible technical solution of this application, the width of the arc-shaped flange is between 5 and 15 centimeters, the maximum horizontal width of the curved panel is between 2.5 and 4 meters, and the maximum vertical height of the curved panel is between 1.5 and 2.5 meters.

[0017] In summary, this application includes at least one of the following beneficial technical effects: No need for customized large stamping dies and matching ultra-large tonnage stamping equipment; large plates with widths of 2.5-4 meters can be processed using only conventional rolling mills, significantly reducing equipment investment costs (saving hundreds of thousands of yuan in die costs); at the same time, the bending process adopts step-by-step pushing and parametric control, avoiding local cracking or wrinkling of the plate that may be caused by overall stamping, and improving the yield rate of large-size curved surface forming; in step three, the curvature of the arc edge of the reinforcing plate is made consistent with the curvature of the curved blank plate, providing a structural basis for subsequent welding and bonding, ensuring a tight fit between the reinforcing plate and the inner surface of the curved plate, and avoiding insufficient welding strength caused by point contact or line contact; After the curved edges of the reinforcing plate are welded together, a forming mold matching the shape of the head blank is used for pressure holding and shaping. This solves the problems of springback and local deformation that may occur in the curved blank after bending. By holding the pressure, the shape is stabilized and solidified, ensuring the final contour accuracy of the head (e.g., the radius of curvature error can be controlled within ±2mm). Compared with direct stamping, the step-by-step strategy of "rough bending and fine shaping with pressure holding" reduces the requirements for equipment tonnage and achieves high dimensional accuracy. In addition, the welding of the reinforcing plate and the curved plate enhances the local rigidity of the head, enabling it to withstand the loads during the transportation and use of large oil tanks. Using a spinning machine, an inward-facing arc-shaped flange is created around the perimeter of the curved blank plate. This flange not only increases the structural strength of the end cap edge (equivalent to a reinforcing rib), preventing edge deformation during transportation and welding, but also facilitates subsequent butt welding with the tank body sections. The inner flange can naturally form a welding bevel or positioning step, improving the tank assembly efficiency. Compared with traditional end caps (without flanges or with outward flanges), the inner arc-shaped flange can also avoid external impact damage and improve the appearance. The entire method ultimately enabled the low-cost, efficient, and precise production of large, irregularly shaped heads, breaking through the industry's technical prejudice that large-size heads must rely on large-scale stamping equipment. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a process flow chart of the actual product corresponding to each step in the embodiments of this application.

[0020] Figure 2 This is a schematic diagram of the structure of the irregularly shaped head of a large oil tank in an embodiment of this application.

[0021] Explanation of reference numerals in the attached figures: 1. Curved panel; 11. Arc-shaped flange; 2. Reinforcing plate; 21. Arc-shaped edge; 22. Vertical folded edge; 23. Weight reduction hole. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] The following is in conjunction with the appendix Figure 1-2 This application will be described in further detail.

[0027] This application discloses an irregularly shaped end cap for a large oil tank and its manufacturing method. (Refer to...) Figure 1-2 A method for manufacturing irregularly shaped heads for large oil tanks includes the following steps: Step 1: Create a 3D model of the irregular head according to the preset size and shape. The irregular head includes a curved panel 1 and a reinforcing plate 2 fixed on the inner side of the curved panel 1. Unfold the 3D model of the curved panel 1 into a plane and obtain a planar view of the curved panel 1. Step 2: According to the plan view, use a plasma cutter to cut the raw material into the required shape and size, and obtain the flat material of curved panel 1; Step 3: Adjust the processing parameters of the rolling mill according to the design dimensions of the curved panel 1, and gradually push the flat plate into the rolling mill for bending to obtain a curved blank plate with a corresponding curvature. The processing parameters of the rolling mill include: parallelism of the upper and lower rollers, width and thickness of the plate, material of the plate, target diameter of the roll, clamping force between the upper and lower rollers, rolling speed, single pressing amount and number of pressing passes, and preheating temperature. At the same time, according to the design dimensions of the reinforcing plate 2, cut, punch and / or bend the plate material to obtain the reinforcing plate 2. One side of the reinforcing plate 2 has an arc edge 21, and the curvature of the arc edge 21 is consistent with the curvature of the curved blank plate. Step 4: Attach and weld the curved edge of the reinforcing plate 2 to the inner side of the curved blank plate to obtain the end cap blank. Set positioning marks on the inner side of the curved blank plate according to the design position. Align the curved edge of the reinforcing plate with the positioning marks and then weld it in place. Then, customize a solidification mold that matches the shape of the end cap blank. Place the end cap blank in the solidification mold for pressure holding and shaping until the shape of the end cap blank is stable and solidified. Step 5: Transport the solidified head blank to the spinning machine, and spin a ring of arc-shaped flanges 11 facing inward around the perimeter of the curved blank plate to obtain a large oil tank irregular head. Step Six: Polish and grind the outer perimeter and weld points of the large oil tank's irregularly shaped head.

[0028] The polishing process removes burrs, oxide scale, and welding spatter generated by plasma cutting and swivel, making the edges of the end cap smooth and the weld points flat, thereby reducing stress concentration points and improving fatigue life. At the same time, the polished surface can improve the corrosion resistance of stainless steel parts (avoiding preferential corrosion at weld slag sites), meet the cleanliness and sealing requirements of oil tank end caps, and the appearance quality meets industrial product standards.

[0029] By implementing multi-parameter coordinated control of the rolling mill, it is possible to adaptably bend plates of different thicknesses (e.g., 8-20mm) and materials (e.g., 304 / 316L stainless steel), avoiding wrinkling, edge wavy patterns, or internal wall cracks caused by improper parameters. The preheating temperature parameter is particularly suitable for thick plates or high-strength plates, which can reduce bending internal stress and prevent cold cracking. The limitation of single pressing amount and pressing passes ensures gradual deformation, making the curvature of the curved blank uniform and providing a good foundation for subsequent pressure holding and shaping, thereby improving the overall manufacturing accuracy and yield.

[0030] The positioning marks added to the inner side of the curved blank plate ensure that the welding position of multiple reinforcing plates 2 (such as two plates arranged at intervals) accurately conforms to the design drawings, avoiding the reinforcing plates 2 from deviating from the optimal stress position due to manual visual misalignment; after the arc edge 21 is aligned with the positioning marks, the arc surface naturally fits, eliminating the need for repeated adjustments and improving welding efficiency; at the same time, precise positioning ensures that the composite structure of the reinforcing plate 2 and the curved plate 1 can work together to bear the load, making the stress distribution uniform when the end cap is under force, and preventing local overload failure.

[0031] This application provides a large oil tank irregular-shaped head, which is manufactured by the above-described method. The large oil tank irregular-shaped head is made of stainless steel.

[0032] The large oil tank irregular head includes a curved panel 1 and multiple reinforcing plates 2. The outer periphery of the curved panel 1 has an arc structure and is integrally formed with an arc-shaped flange 11. The horizontal width of the curved panel 1 is greater than its vertical height. The reinforcing plates 2 are arranged horizontally, and the multiple reinforcing plates 2 are arranged vertically at intervals. The inner side of the reinforcing plate 2 is provided with an arc-shaped edge 21, and the outer side of the reinforcing plate 2 is provided with a vertical folded edge 22. The reinforcing plate 2 also has multiple weight-reducing holes 23. There are two reinforcing plates 2. The vertical folded edge 22 of the upper reinforcing plate 2 is arranged towards the top of the curved panel 1, and the vertical folded edge 22 of the lower reinforcing plate 2 is arranged towards the bottom of the curved panel 1. The width of the arc-shaped flange 11 is between 5-15 cm. The maximum horizontal width of the curved panel 1 is between 2.5-4 meters, and the maximum vertical height of the curved panel 1 is between 1.5-2.5 meters.

[0033] Applying the aforementioned low-cost, highly flexible manufacturing method to stainless steel allows for the mass production of large oil tank heads without relying on large stamping equipment, significantly reducing production barriers and investment risks. Stainless steel itself possesses excellent oil resistance, corrosion resistance, and high and low temperature resistance. Combined with the high dimensional accuracy of this method (pressure holding and shaping + rotating and flanging), the final product, while ensuring safety, can be 10%-15% lighter than traditional stamped heads (through the design of weight-reducing holes 23, etc.), and the manufacturing cost can be reduced by more than 30%.

[0034] The large oil tank's irregularly shaped (flat and elongated) end cap is adapted to the cross-sectional shape of large oil tanks for horizontal storage or transportation, improving space utilization compared to traditional elliptical end caps. Multiple horizontally arranged and spaced reinforcing plates 2 effectively resist radial and axial stresses generated by the liquid pressure inside the tank—the upper reinforcing plate 2 inhibits top deformation, while the lower reinforcing plate 2 strengthens the bottom bearing capacity, forming a frame-like support effect. This ensures the end cap remains stable even when subjected to 2-3 times the working pressure, significantly improving safety.

[0035] The curved edge 21 ensures seamless welding with the inner wall of the curved panel 1, increases the welding contact area, and improves the connection strength; the vertical folded edge 22 significantly increases the moment of inertia of the reinforcing plate 2 itself, making it less prone to bending and instability under pressure, achieving higher rigidity with a thinner plate thickness; the weight reduction hole 23 reduces the overall weight of the end cap (the weight reduction of a single plate can reach 20%) without significantly weakening the strength, reducing the fuel consumption of the tanker truck, while facilitating heat dissipation during welding and subsequent inspection of weld quality.

[0036] The vertical folded edges 22 of the two reinforcing plates 2 are arranged facing upwards and downwards respectively. The technical effect is to form a reinforcing structure with opposite directions—the upper reinforcing plate 2, with its folded edge facing upwards, can resist the upward deformation tendency caused by the pressure inside the tank; the lower reinforcing plate 2, with its folded edge facing downwards, can resist the downward compression of the tank's own weight and the hydrostatic pressure of the liquid. This complementary arrangement maximizes and symmetrically maximizes the bending stiffness of the end cap in the vertical direction, avoiding localized soft areas caused by folded edges in the same direction. It is particularly suitable for large oil tanks under combined stress conditions such as transportation bumps or hydraulic shocks, extending the service life of the end cap.

[0037] The beneficial technical effects of the large oil tank irregular-shaped head and its manufacturing method according to the embodiments of this application are roughly as follows: Without the need for customized large stamping dies and supporting ultra-large tonnage stamping equipment, large plates with widths of 2.5-4 meters can be processed using only conventional rolling mills, significantly reducing equipment investment costs (saving hundreds of thousands of yuan in mold costs); at the same time, the bending process adopts step-by-step pushing and parametric control, avoiding local cracking or wrinkling of the plate that may be caused by overall stamping, and improving the yield rate of large-size curved surface forming; in step three, the curvature of the arc edge 21 of the reinforcing plate 2 is made consistent with the curvature of the curved blank plate, providing a structural basis for subsequent welding and bonding, ensuring that the reinforcing plate 2 and the inner side of the curved plate 1 fit tightly, avoiding insufficient welding strength caused by point contact or line contact; After the arc-shaped edge 21 of the reinforcing plate 2 is welded together, a forming mold matching the shape of the end cap blank is used for pressure holding and shaping. This solves the problems of springback and local deformation that may exist in the curved blank after bending. By holding the pressure, the shape is stabilized and solidified, ensuring the final contour accuracy of the end cap (such as the radius of curvature error can be controlled within ±2mm). Compared with direct stamping, the step-by-step strategy of "rough bending and fine shaping with pressure holding" reduces the requirements for equipment tonnage and achieves high dimensional accuracy. In addition, the welding of the reinforcing plate 2 and the curved plate 1 enhances the local rigidity of the end cap, enabling it to withstand the loads during the transportation and use of large oil tanks. Using a spinning machine, an inward-facing arc-shaped flange 11 is spun around the perimeter of the curved blank plate. This flange not only increases the structural strength of the end cap edge (equivalent to a reinforcing rib) and prevents edge deformation during transportation and welding, but also facilitates subsequent butt welding with the tank body sections. The inner flange can naturally form a welding bevel or positioning step, improving the tank assembly efficiency. Compared with traditional end caps (without flanges or with outward flanges), the inner arc-shaped flange 11 can also avoid external impact damage and improve the appearance. The entire method ultimately enabled the low-cost, efficient, and precise production of large, irregularly shaped heads, breaking through the industry's technical prejudice that large-size heads must rely on large-scale stamping equipment.

[0038] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for manufacturing an irregularly shaped end cap for a large oil tank, characterized in that, Includes the following steps: Step 1: Perform a three-dimensional model of the irregular head according to the preset size and shape. The irregular head includes a curved panel (1) and a reinforcing plate (2) fixed on the inner side of the curved panel (1). Unfold the three-dimensional model of the curved panel (1) into a plane and obtain a planar view of the curved panel (1). Step 2: According to the plan view, use a plasma cutter to cut the raw material of the board into the required shape and size, and obtain the flat board of the curved panel (1); Step 3: Adjust the processing parameters of the rolling machine according to the design dimensions of the curved panel (1), and gradually push the flat plate into the rolling machine for bending to obtain a curved blank plate with the corresponding curvature; at the same time, according to the design dimensions of the reinforcing plate (2), cut, punch and / or bend the plate material to obtain the reinforcing plate (2). One side of the reinforcing plate (2) has an arc edge (21), and the curvature of the arc edge (21) is consistent with the curvature of the curved blank plate. Step 4: The arc-shaped edge of the reinforcing plate (2) is attached and welded to the inner side of the curved blank plate to obtain the head blank; then a solid mold matching the shape of the head blank is customized, and the head blank is placed in the solid mold for pressure holding and shaping until the shape of the head blank is stable and solidified. Step 5: Transport the solidified head blank to the spinning machine, and spin an arc-shaped flange (11) around the perimeter of the curved blank plate facing inward to obtain a large oil tank irregular head.

2. The method for manufacturing a large oil tank irregular-shaped head according to claim 1, characterized in that, It also includes step six: polishing and grinding the outer periphery and weld points of the large oil tank's irregularly shaped head.

3. The method for manufacturing a large oil tank irregular-shaped head according to claim 1, characterized in that, In step three, the processing parameters of the rolling machine include: parallelism of the upper and lower rollers, width and thickness of the sheet material, material of the sheet material, target diameter of the roll, clamping force between the upper and lower rollers, rolling speed, single pressing amount, number of pressing passes, and preheating temperature.

4. The method for manufacturing a large oil tank irregular-shaped head according to claim 1, characterized in that, In step four, positioning marks are set on the inner side of the curved blank plate according to the design position. After aligning the arc edge (21) of the reinforcing plate (2) with the positioning marks, welding is performed to fix it.

5. A large oil tank irregular-shaped end cap, characterized in that, The large oil tank irregular head is made of stainless steel and is manufactured by the manufacturing method described in any one of claims 1-4.

6. The large oil tank irregular-shaped head according to claim 5, characterized in that, The large oil tank irregular head includes a curved panel (1) and multiple reinforcing plates (2). The outer periphery of the curved panel (1) is an arc structure and is integrally formed with an arc-shaped flange (11). The horizontal width of the curved panel (1) is greater than its vertical height. The reinforcing plates (2) are arranged horizontally, and the multiple reinforcing plates (2) are arranged vertically at intervals.

7. The large oil tank irregular-shaped head according to claim 6, characterized in that, The inner side of the reinforcing plate (2) is provided with an arc-shaped edge (21), the outer side of the reinforcing plate (2) is provided with a vertical folded edge (22), and the reinforcing plate (2) also has multiple weight-reducing holes (23).

8. The large oil tank irregular-shaped head according to claim 7, characterized in that, The reinforcing plate (2) is provided in two parts, wherein the vertical fold (22) of the upper reinforcing plate (2) is arranged towards the top of the curved panel (1), and the vertical fold (22) of the lower reinforcing plate (2) is arranged towards the bottom of the curved panel (1).

9. The large oil tank irregular-shaped head according to claim 6, characterized in that, The width of the arc-shaped flange (11) is between 5 and 15 centimeters, the maximum horizontal width of the curved panel (1) is between 2.5 and 4 meters, and the maximum vertical height of the curved panel (1) is between 1.5 and 2.5 meters.

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