Method for manufacturing a fuel tank and fuel tank

Abstract

The application belongs to the technical field of container manufacturing, and discloses a fuel tank manufacturing method and a fuel tank. The fuel tank manufacturing method comprises the following steps: S1, manufacturing a plane plate, an arc-shaped plate and a spherical plate; S2, welding the arc-shaped plate on four edges of the plane plate, and welding the spherical plate between every two adjacent arc-shaped plates to form a bottom section; S3, welding the arc-shaped plate on four edges of the plane plate, welding the spherical plate between every two adjacent arc-shaped plates, and opening a plurality of connecting through holes on the plane plate to form a top section; S4, welding the arc-shaped plate between every two adjacent plane plates to form a main body section; and S5, welding the main body section, the bottom section and the top section in the form of a butt joint weld. The edges of the fuel tank are arc-shaped, and the sharp corners are spherical, which greatly relieves the stress concentration phenomenon of the welds at the edges and the sharp corners of the fuel tank, and the form of the butt joint weld improves the sealing and safety of the welds.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of container manufacturing, in particular to a fuel tank manufacturing method and a fuel tank. BACKGROUND

[0002] Fuel is essential for the running of a ship, so the storage of fuel in a ship is of great importance. Currently, one or more fuel tanks for storing fuel are arranged in the hold of a ship.

[0003] The fuel tank commonly used at present is usually a complete cube structure obtained by assembling six plane plates vertically with each other and welding through flat corner weld seams.

[0004] The fuel tank of this structure has a very serious stress concentration phenomenon at the positions of twelve edges, especially at the positions of three weld seams vertically intersecting at the eight corners of the cube, because the six plane plates are vertically arranged and welded through flat corner weld seams. In addition, since the flat corner weld seam is a non-penetration weld seam, the weld seam is prone to damage under complex stress conditions, thereby causing fuel leakage, low sealing performance, low reliability and poor safety. SUMMARY

[0005] The present application aims to provide a fuel tank manufacturing method and a fuel tank with small weld seam stress concentration, good sealing performance, high reliability and strong safety.

[0006] To achieve this goal, the present application adopts the following technical solutions:

[0007] On the one hand, a fuel tank manufacturing method is provided, comprising the following steps:

[0008] S1, preparing plates: according to the specifications of the fuel tank, a plurality of plane plates, a plurality of arc-shaped plates and a plurality of spherical plates are prepared respectively;

[0009] S2, manufacturing a bottom section: the arc-shaped plates are welded on the four edges of the plane plates, and the spherical plates are welded between every two adjacent arc-shaped plates to form the bottom section;

[0010] S3, manufacturing a top section: the arc-shaped plates are welded on the four edges of the plane plates, the spherical plates are welded between every two adjacent arc-shaped plates, and a plurality of connecting through holes for connecting with external pipelines are formed on the plane plates to form the top section;

[0011] S4, manufacturing a main body section: the arc-shaped plates are welded between every two adjacent plane plates to form the main body section;

[0012] S5, assembly welding: the main body is welded on the bottom section by butt welding, and the top section is welded on the main body;

[0013] S6, post-welding treatment: the welds of each welding position are cleaned.

[0014] Optionally, step S1 specifically comprises the following steps:

[0015] S11, the flat panel comprises a plurality of sub-panels and a first connecting structure, the first connecting structure is welded at a corresponding position on each of the plurality of sub-panels to form the flat panel;

[0016] S12, the arc-shaped panel comprises an arc-shaped main panel and a second connecting structure, the second connecting structure is welded at a corresponding position on the arc-shaped main panel to form the arc-shaped panel;

[0017] S13, the spherical panel is an eighth of a spherical surface structure with the same radius as the arc-shaped panel.

[0018] Optionally, step S11 specifically comprises the following steps:

[0019] S111, a welding bevel of the butt welding towards the inside of the fuel tank is formed on each of the plurality of sub-panels, the welding bevels of the plurality of sub-panels are placed downward on an assembly support, and the first connecting structure is positioned and welded at a corresponding position on the sub-panels;

[0020] S112, starting from the middle sub-panel, the first connecting structure and the flat corner weld between the first connecting structure and the sub-panels are gradually symmetrically constructed to complete the perimeter closure welding;

[0021] S113, after completing the perimeter closure welding of the first connecting structure and the sub-panels, the sub-panels are turned over so that the welding bevels of the butt welds are upward;

[0022] S114, the butt welds between the plurality of sub-panels are leveled and fixed by using a no-foot assembly tooling, and the butt welds between the plurality of sub-panels outside the area where the no-foot assembly tooling is located are welded;

[0023] S115, the no-foot assembly tooling is removed, and the butt welds between the plurality of sub-panels are continuously welded.

[0024] Optionally, step S2 specifically comprises the following steps:

[0025] S21, placing the inside surface of the flat panel upward on an assembly support;

[0026] S22, the second connecting structure is fixed by positioning welding with the first connecting structure on the plane plate, and the outer side of the second connecting structure is temporarily welded and fixed with the assembly support;

[0027] S23, the gap of the butt welding seam between the arc-shaped plate and the plane plate is adjusted, and the arc-shaped plate is fixed with the second connecting structure by positioning welding;

[0028] S24, the gap between the spherical plate and the arc-shaped plate is adjusted, and the butt welding seam between the spherical plate and the arc-shaped plate and the butt welding seam between the plane plate and the arc-shaped plate are leveled and fixed by using a code-free assembly tooling;

[0029] S25, the butt welding seam between the spherical plate and the arc-shaped plate and the butt welding seam between the plane plate and the arc-shaped plate are welded;

[0030] S26, the butt welding seam between the first connecting structure and the second connecting structure is welded;

[0031] S27, the flat corner welding seam between the second connecting structure and the arc-shaped plate is welded.

[0032] Optionally, step S4 specifically comprises the following steps:

[0033] S41, the plane plate is placed in a vertical state on the assembly support, and is temporarily welded and fixed with the assembly support through the first connecting structure;

[0034] S42, the second connecting structure is fixed at the corresponding position of the assembly support, and is fixed with the corresponding first connecting structure by positioning welding;

[0035] S43, the gap of the butt welding seam between the arc-shaped plate and the plane plate is adjusted, and the arc-shaped plate is fixed with the second connecting structure by positioning welding;

[0036] S44, the butt welding seam between the arc-shaped plate and the plane plate is leveled and fixed by using a code-free assembly tooling;

[0037] S45, the butt welding seam between the arc-shaped plate and the plane plate is welded;

[0038] S46, the butt welding seam between the second connecting structure and the first connecting structure is welded;

[0039] S47, the flat corner welding seam between the arc-shaped plate and the second connecting structure is welded.

[0040] Optionally, step S5 specifically comprises the following steps:

[0041] S51, hoist the bottom segment to a corresponding installation position, where a third connecting structure corresponding to the first and second connecting structures is connected, and weld and fix the first and second connecting structures on the bottom segment to the corresponding third connecting structures respectively;

[0042] S52, hoist the main body segment above the bottom segment, adjust the gap of the butt joint weld between the main body segment and the bottom segment, and then weld and fix the first and second connecting structures on the main body segment to the corresponding third connecting structures respectively;

[0043] S53, weld the butt joint weld between the main body segment and the bottom segment after positioning and leveling using the code-free assembly tooling;

[0044] S54, weld the butt joint weld between the first connecting structure on the main body segment and the second connecting structure on the bottom segment;

[0045] S55, hoist the top segment above the main body segment, adjust the gap between the top segment and the main body segment, and then weld and fix the first and second connecting structures on the top segment to the corresponding third connecting structures respectively;

[0046] S56, weld the butt joint weld between the main body segment and the top segment after positioning and leveling using the code-free assembly tooling;

[0047] S57, weld the butt joint weld between the first connecting structure on the main body segment and the second connecting structure on the top segment;

[0048] S58, weld the external pipeline in the connecting through hole.

[0049] Optionally, when welding the external pipeline in the connecting through hole, the weld on the outside of the fuel tank is welded first, and then the weld on the inside of the fuel tank is welded.

[0050] Optionally, step S6 specifically includes the following steps:

[0051] S61, clean and polish each weld using a polishing sheet;

[0052] S62, apply a special passivation paste to the weld on the inside of the fuel tank to perform passivation treatment on the weld;

[0053] S63, flushing the entire fuel tank with tap water.

[0054] Optionally, the no-foot assembly tool comprises a compression bolt, a tool support, an insertion connecting plate and a compression leveling plate, and the specific steps of leveling and fixing the butt weld using the no-foot assembly tool are as follows:

[0055] Step 1: a first insertion slot is formed on the insertion connecting plate, the tool support is inserted into the first insertion slot, and the insertion connecting plate is inserted into the butt weld;

[0056] Step 2: a second insertion slot is formed on the insertion connecting plate, the compression leveling plate is inserted into the second insertion slot, and the compression leveling plate is abutted against the end faces of the components on both sides of the butt weld;

[0057] Step 3: a threaded hole is formed on the tool support, the compression bolt is inserted into the threaded hole, the compression leveling plate is compressed against the end faces of the components on both sides of the butt weld by tightening the compression bolt, and the end portions of the tool support and the compression bolt are compressed against the upper surfaces of the components on both sides of the butt weld.

[0058] In another aspect, a fuel tank is provided, which is manufactured by the fuel tank manufacturing method described in any one of the above aspects.

[0059] The beneficial effects of the present application are as follows:

[0060] The present application provides a fuel tank manufacturing method and a fuel tank, which are manufactured by respectively manufacturing a bottom segment, a top segment and a main body segment from a plurality of planar plates, a plurality of arc-shaped plates and a plurality of spherical plates, and welding the segments by adopting a butt weld as a joint, so that the edges of the fuel tank are arc surfaces and the sharp corners are spherical surfaces, which greatly relieves the stress concentration phenomenon of the welds at the edges and sharp corners of the fuel tank, and the various components of the fuel tank are welded by adopting a butt weld, which is more compact and more secure than a square corner weld, thereby avoiding the problem of weld damage under complex stress conditions and causing fuel leakage, improving the reliability of the weld, improving the sealing performance of the weld and enhancing the safety of the fuel tank. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 is a step diagram of the fuel tank manufacturing method of the present application;

[0062] Figure 2 is a specific step diagram of step S1 in the fuel tank manufacturing method of the present application;

[0063] Figure 3 is a specific step diagram of step S11 in step S1 of the present application;

[0064] Figure 4 is a specific step diagram of step S2 in the fuel tank manufacturing method of the present application;

[0065] Figure 5 is a specific step diagram of step S4 in the fuel tank manufacturing method of the present application;

[0066] Figure 6 is a specific step diagram of step S5 in the fuel tank manufacturing method of the present application;

[0067] Figure 7 is a specific step diagram of step S6 in the fuel tank manufacturing method of the present application;

[0068] Figure 8 is a step diagram of leveling and fixing using the codeless foot assembly tool of the present application;

[0069] Figure 9 is a three-dimensional diagram of the fuel tank of the present application;

[0070] Figure 10 is a structural exploded diagram of the bottom section of the present application;

[0071] Figure 11 is a structural exploded diagram of the top section of the present application;

[0072] Figure 12 is a structural exploded diagram of the main body section of the present application;

[0073] Figure 13 is a structural diagram of the flat plate of the present application;

[0074] Figure 14 is a structural diagram of the arc-shaped plate of the present application;

[0075] Figure 15 is a connection diagram of the split plate and the first connection structure of the present application.

[0076] In the figure:

[0077] 100, butt weld;

[0078] 1, flat plate; 11, split plate; 12, first connection structure;

[0079] 2, arc-shaped plate; 21, arc-shaped main plate; 22, second connection structure;

[0080] 3, spherical plate;

[0081] 4, bottom section;

[0082] 5, top section;

[0083] 6, main body section;

[0084] 7. External pipe; 71, access passage; 72, access piping; 73, egress piping. DETAILED DESCRIPTION

[0085] The application will be further described below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are intended to be merely exemplary of the application and that the application is not limited to such exemplary embodiments. It should also be understood that, in the description of the embodiments, the terms "upper", "lower", "right", "left", and the like are used for convenience with reference to the orientation of the drawings and are not intended to be limiting of the application. In addition, the terms "first" and "second" are used merely for differentiation in description and do not have special meanings.

[0086] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0087] In the present application, unless otherwise explicitly specified and limited, "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, "on", "above" and "above" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. "Below", "below" and "below" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0088] In the description of the embodiments, the terms "upper", "lower", "right", "left", and the like are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application. In addition, the terms "first" and "second" are merely used to distinguish in description and do not have special meanings.

[0089] In order to reduce the stress concentration at the weld, improve the reliability, sealing and safety of the weld, the present embodiment provides a fuel tank manufacturing method.

[0090] As shown in Figure 1 , Figures 9 to 12 , the fuel tank manufacturing method comprises the following steps:

[0091] S1, making plates: according to the size of the fuel tank, a plurality of flat plates 1, a plurality of arc plates 2 and a plurality of spherical plates 3 are made respectively;

[0092] S2, making bottom section 4: arc plates 2 are welded on the four edges of the flat plate 1, and spherical plates 3 are welded between every two adjacent arc plates 2 to form the bottom section 4;

[0093] S3, making top section 5: arc plates 2 are welded on the four edges of the flat plate 1, spherical plates 3 are welded between every two adjacent arc plates 2, and a plurality of connecting through holes for connecting with external pipeline 7 are opened on the flat plate 1 to form the top section 5;

[0094] S4, making main section 6: arc plates 2 are welded between every two adjacent flat plates 1 to form the main section 6;

[0095] S5, assembly and welding: the main section 6 is welded on the bottom section 4 and the top section 5 is welded on the main section 6 by using the joint in the form of butt weld 100;

[0096] S6, post-welding treatment: the welds at each welding position are cleaned.

[0097] The bottom section 4, the top section 5 and the main section 6 are made by a plurality of flat plates 1, a plurality of arc plates 2 and a plurality of spherical plates 3 respectively, and are welded by using the joint in the form of butt weld 100 to form the fuel tank, so that the edges of the fuel tank are arc surfaces and the sharp corners are spherical surfaces, which greatly relieves the stress concentration phenomenon of the welds at the edges and sharp corners of the fuel tank, and each component of the fuel tank is welded by using the joint in the form of butt weld 100, which is more compact and more firm than flat corner weld, avoids the problem of weld damage under complex stress conditions, thereby causing fuel leakage, improves the reliability of the weld, improves the sealing performance of the weld and enhances the safety of the fuel tank.

[0098] The fuel tank manufacturing method can be used in different fields, and in the present embodiment, it is mainly used for manufacturing a formaldehyde tank in a ship tank. Since formaldehyde is a toxic substance, when the fuel tank manufacturing method is used to manufacture the formaldehyde tank, the planar plate 1, the arc-shaped plate 2 and the spherical plate 3 are all made of 316L stainless steel with excellent corrosion resistance. The arc-shaped plate 2 is formed by rolling a 316L stainless steel flat plate, and the spherical plate 3 is made of a spherical 316L stainless steel. During manufacturing, the processing factory can process and open the welding bevel according to the relevant design drawings provided by the shipyard, as a standard part, so as to facilitate manufacturing and replacement in the later stage, and when opening the bevel, mechanical processing or plasma cutting method is used. All bevel directions are directed towards the inside of the methanol tank, and the angle of all bevels is single-sided 20±5 degrees. The root gap of all butt welds 100 is any value between 6mm-8mm, such as 6mm, 7mm and 8mm. The planar plate 1 used to make the top section 5 can open the connecting hole in the blanking stage in advance, so as to facilitate the differentiation of the planar plate 1 used to make the top section 5 and the planar plate 1 used to make the bottom section 4.

[0099] Specifically, as shown in Figure 2 、 Figures 9 to 14 , step S1 specifically includes the following steps:

[0100] S11, the planar plate 1 includes a plurality of split plates 11 and a first connecting structure 12, and the first connecting structure 12 is welded at the corresponding position on each of the plurality of split plates 11 to form the planar plate 1.

[0101] S12, the arc-shaped plate 2 includes an arc-shaped main plate 21 and a second connecting structure 22, and the second connecting structure 22 is welded at the corresponding position on the arc-shaped main plate 21 to form the arc-shaped plate 2.

[0102] S13, the spherical plate 3 is made of an eighth of a spherical surface structure with the same radius as the arc-shaped plate 2.

[0103] By welding the first connecting structure 12 on the split plate 11 and the second connecting structure 22 on the arc-shaped plate 2, when the planar plate 1, the arc-shaped plate 2 and the spherical plate 3 form the top section 5, the main section 6 and the bottom section 4, the first connecting structure 12 and the second connecting structure 22 rigidly constrain the planar plate 1 and the arc-shaped plate 2, so that the deformation of the planar plate 1 and the arc-shaped plate 2 after welding is small, thereby facilitating the leveling and shaping of the planar plate 1 and the arc-shaped plate 2.

[0104] In the present embodiment, the first connecting structure 12 and the split plate 11, and the second connecting structure 22 and the arc-shaped main plate 21 are all welded by means of a flat corner weld, and the first connecting structure 12 and the second connecting structure 22 are both made of carbon steel with good welding performance.

[0105] Specifically, Figure 3 、 Figure 13 、 Figure 15 As shown in FIG. 1, step S11 specifically comprises the following steps:

[0106] S111, the welding bevels of the plurality of split plates 11 towards the butt weld 100 inside the fuel tank are opened, the welding bevels of the plurality of split plates 11 are laid down on the assembly support, and the first connecting structure 12 is positioned and welded at the corresponding position on the split plate 11;

[0107] S112, starting from the middle split plate 11, the construction is gradually symmetric to both ends, and the flat corner weld between the first connecting structure 12 and the split plate 11 is completed for the circumferential seal welding;

[0108] S113, after the circumferential seal welding of the first connecting structure 12 and the split plate 11 is completed, the split plate 11 is turned over so that the welding bevel of the butt weld 100 is upwards;

[0109] S114, the butt weld 100 between the plurality of split plates 11 is leveled and fixed by using the non-code foot assembly tooling, and the butt weld 100 between the plurality of split plates 11 outside the area where the non-code foot assembly tooling is located is welded;

[0110] S115, the non-code foot assembly tooling is removed, and the butt weld 100 between the plurality of split plates 11 is continuously welded.

[0111] By using the non-code foot assembly tooling to level and fix the butt weld 100 when manufacturing the flat plate 1, the accuracy of the position of the plurality of split plates 11 during welding is ensured, and the welding effect is enhanced. At the same time, the non-code foot assembly tooling avoids welding temporary assembly corner codes during manufacturing, solves the problems of high difficulty, long cycle and high cost during removal of the assembly corner codes, and avoids damage to the surface of the flat plate 1 during removal of the assembly corner codes, ensuring the appearance to be flat and beautiful.

[0112] In step S111 of the embodiment, when the plurality of split plates 11 are positioned and welded with the first connecting structure 12, the positioning and welding of the split plates 11 and the first connecting structure 12 is first performed from the split plate 11 at the middle position. Before the positioning and welding, it is ensured that the first connecting structure 12 is in sufficient contact with the split plate 11, and the gap between them is ≤0.2mm. Symmetrical intermittent welding is performed using CO2 gas shielded welding. The welding material is E309MoL series stainless steel flux-cored wire. The CO2 gas purity is ≥99.5%. The welding wire diameter is Φ1.2mm. The welding current is 180A-220A. The positioning and welding length is 30mm-50mm. The positioning and welding spacing is 300mm-500mm. The positioning and welding leg size is ≤80% of the designed leg size. After the positioning and welding of the first split plate 11 and the corresponding first connecting structure 12 is completed, the adjacent split plates 11 are adjusted to ensure that the end portions of the plurality of split plates 11 are flush and the gap at the root of the bevel is maintained at 6mm-8mm. The positioning and welding of the remaining split plates 11 and the corresponding first connecting structure 12 is completed according to the above method. At this time, all the split plates 11 of the flat plate 1 are neatly and uniformly positioned and welded with the first connecting structure 12. The gap at the root of the butt weld 100 of the split plates 11 is uniform to ensure the welding effect and efficiency.

[0113] In step S112 of the embodiment, when the perimeter closure welding of the fillet weld between the split plates 11 and the corresponding first connecting structure 12 is performed, two welders are used to perform symmetrical welding from the center position to the both ends of the plurality of split plates 11. CO2 gas shielded welding is used for welding. The welding material is 309MoL series stainless steel flux-cored wire. The CO2 gas purity is ≥99.5%. The welding wire diameter is Φ1.2mm. The welding current is 180A-220A. The leg size is 100%-110% of the designed leg size. Thus, the perimeter closure welding of the fillet weld between the plurality of split plates 11 and the corresponding first connecting structure 12 is completed to ensure the welding effect and efficiency.

[0114] In step S114 of the embodiment, when the butt weld 100 between the plurality of split plates 11 is welded, ceramic gaskets can be used for assistance. Single-sided welding with double-sided forming CO2 gas shielded welding is used for welding. The welding material is 316L series stainless steel flux-cored wire. The CO2 gas purity is ≥99.5%. The welding wire diameter is Φ1.2mm. The welding current for the base layer of the weld is 160A-180A. The welding current for the other layers is 180A-210A. The interlayer temperature of the weld is ≤150℃ to ensure the welding effect and efficiency.

[0115] When the butt weld 100 between the plurality of split plates 11 is welded, there are three stages:

[0116] In the first stage, the plurality of split plates 11 are fixed and leveled by using code-free assembly fixtures, wherein the interval between every two adjacent code-free assembly fixtures is 300-400 mm. Then, the backing layer and the filler layer of the butt weld 100 in the area other than the code-free assembly fixtures are welded by using CO2 gas shielded welding with single-sided welding and double-sided forming with the aid of ceramic pads.

[0117] In the second stage, the code-free assembly fixtures and the ceramic pads are removed, and the two ends of all the butt welds 100 (in the area other than the code-free assembly fixtures) that have been welded are polished and shaped so that the ends of the backing layer of the welds are flush with the base material, thereby ensuring that the welds can be in full contact with the ceramic pads to be installed subsequently, and the backing layer and the filler layer are free of defects such as end shrinkage holes and have reduced end thickness, thereby ensuring the joint fusion quality of the subsequent backing welds. The backing layer and the filler layer of the butt welds 100 in the entire area are welded by using CO2 gas shielded welding with single-sided welding and double-sided forming with the aid of ceramic pads, and after the welding is completed, the welds are polished and shaped.

[0118] In the third stage, the cover layer of the butt welds 100 between all the split plates 11 is continuously welded by using CO2 gas shielded welding, the welding material is 316L series stainless steel flux-cored wire, the purity of CO2 gas is greater than or equal to 99.5%, the diameter of the welding wire is Φ1.2 mm, the welding current is 180-210 A, and the interlayer temperature of the weld is less than or equal to 150°C. Thus, the welding work of the butt welds 100 between the plurality of split plates 11 is completed, and the flat plate 1 has good integrity and excellent sealing performance.

[0119] Specifically, Figure 4 、 Figure 10 、 Figure 11 、 Figures 13 to 15 As shown in FIG. 1, step S2 specifically includes the following steps:

[0120] S21, placing the in-cabin surface of the flat plate 1 upwards on an assembly support;

[0121] S22, positioning and welding the second connecting structure 22 with the first connecting structure 12 on the flat plate 1, and temporarily welding and fixing the outer side of the second connecting structure 22 with the assembly support;

[0122] S23, adjusting the gap of the butt weld 100 between the arc-shaped plate 2 and the flat plate 1, and positioning and welding the arc-shaped plate 2 with the second connecting structure 22;

[0123] S24, adjusting the gap between the spherical plate 3 and the arc-shaped plate 2, and leveling and fixing the butt weld 100 between the spherical plate 3 and the arc-shaped plate 2 and the butt weld 100 between the flat plate 1 and the arc-shaped plate 2 by using code-free assembly fixtures;

[0124] S25, welding the butt weld 100 between the spherical plate 3 and the arc-shaped plate 2 and the butt weld 100 between the flat plate 1 and the arc-shaped plate 2;

[0125] S26, welding the butt weld 100 between the first connecting structure 12 and the second connecting structure 22;

[0126] S27, welding the fillet weld between the second connecting structure 22 and the arc-shaped plate 2.

[0127] By cooperation of the first connecting structure 12 and the second connecting structure 22, the arc-shaped plate 2 and the flat plate 1 of the bottom section 4 are positioned, the gap of the butt weld 100 between the arc-shaped plate 2 and the flat plate 1 is ensured to be within a specified range, and the arc-shaped plate 2 and the flat plate 1 are rigidly constrained by the first connecting structure 12 and the second connecting structure 22, so as to reduce the deformation amount occurring when the butt weld 100 is welded, thereby facilitating the later leveling and shaping, and the code-free assembly tooling is used to level and fix the butt weld 100 between the spherical plate 3 and the arc-shaped plate 2 and the butt weld 100 between the flat plate 1 and the arc-shaped plate 2, which not only ensures the accuracy of the connection position of the arc-shaped plate 2, the flat plate 1 and the spherical plate 3 during welding, enhances the welding effect, but also avoids welding temporary assembly corner codes during the manufacturing process, solves the problems of great difficulty, long cycle and high cost when the assembly corner codes are removed, and avoids damage to the surface when the assembly corner codes are removed, thereby ensuring the smooth and beautiful appearance of the bottom section 4.

[0128] In the embodiment, the gap of the butt weld 100 is between 6mm and 8mm, and in step S23, when the arc-shaped plate 2 and the second connecting structure 22 of the bottom section 4 are tack welded, it is ensured that the second connecting structure 22 is in full contact with the arc-shaped plate 2, and the gap therebetween is ≤0.2mm, the CO2 gas shielded welding is used for symmetrical intermittent welding and fixing, the welding material is E309MoL series stainless steel flux-cored wire, the purity of CO2 gas is ≥99.5%, the welding wire diameter is Φ1.2mm, the welding current is 180A-220A, the tack welding length is 30mm-50mm, the tack welding spacing is 300mm-500mm, and the tack welding leg size is ≤80% of the designed leg size.

[0129] When the butt welds 100 between the spherical plate 3 and the arc plate 2 and between the plane plate 1 and the arc plate 2 are welded after being leveled and fixed by the codeless foot assembly tool, CO2 gas shielded welding assisted by ceramic pads can be used to weld the butt welds 100 between the spherical plate 3 and the arc plate 2 and between the plane plate 1 and the arc plate 2, the welding material is 316L series stainless steel flux-cored wire, the purity of CO2 gas is ≥99.5%, the diameter of the welding wire is Φ1.2mm, the welding current of the weld backing layer is 160A-180A, the welding current of other layers is 180A-210A, and the interlayer temperature of the weld is ≤150℃. The welding process is the same as the welding process of the butt welds 100 between the plurality of split plates 11.

[0130] In addition, when the butt welds 100 between the first connecting structure 12 and the second connecting structure 22 of the bottom section 4 are welded in step S26, CO2 gas shielded welding is used, the welding material is E501T-1 series carbon steel flux-cored wire, the purity of CO2 gas is ≥99.5%, the diameter of the welding wire is Φ1.2mm, and the welding current is 190A-230A.

[0131] When the butt welds 100 between the arc plate 2 and the second connecting structure 22 are welded in step S27, CO2 gas shielded welding is used, the welding material is E309MoL series stainless steel flux-cored wire, the purity of CO2 gas is ≥99.5%, the diameter of the welding wire is Φ1.2mm, and the welding current is 180A-220A.

[0132] Since the structure of the top section 5 is only different from the structure of the bottom section 4 in that the plane plate 1 is provided with connecting through holes, the process of manufacturing the top section 5 in step S3 is the same as the process of manufacturing the bottom section 4 in step S2, and will not be described here.

[0133] Specifically, as shown in Figure 5 , Figures 12 to 15 , step S4 specifically includes the following steps:

[0134] S41, place the plane plate 1 in a vertical state on the assembly support, and temporarily weld and fix the plane plate 1 with the assembly support through the first connecting structure 12;

[0135] S42, fix the second connecting structure 22 at the corresponding position of the assembly support, and positionally weld and fix the second connecting structure 22 with the corresponding first connecting structure 12;

[0136] S43, adjust the gap of the butt weld 100 between the arc plate 2 and the plane plate 1, and positionally weld and fix the arc plate 2 with the second connecting structure 22;

[0137] S44, the butt weld 100 between the arc-shaped plate 2 and the flat plate 1 is leveled and fixed by using a code-free foot assembly tool;

[0138] S45, the butt weld 100 between the arc-shaped plate 2 and the flat plate 1 is welded;

[0139] S46, the butt weld 100 between the second connecting structure 22 and the first connecting structure 12 is welded;

[0140] S47, the flat corner weld between the arc-shaped plate 2 and the second connecting structure 22 is welded.

[0141] By cooperation of the first connecting structure 12 and the second connecting structure 22, the arc-shaped plate 2 and the flat plate 1 of the main body segment 6 are positioned, the gap of the butt weld 100 between the arc-shaped plate 2 and the flat plate 1 is ensured to be within a specified range, and the arc-shaped plate 2 and the flat plate 1 are rigidly constrained by the first connecting structure 12 and the second connecting structure 22, thereby reducing the deformation amount occurring when the butt weld 100 is welded, thereby facilitating later leveling and shaping, and the code-free foot assembly tool is used to level and fix the butt weld 100 between the flat plate 1 and the arc-shaped plate 2, which not only ensures the accuracy of the connection position of the arc-shaped plate 2 and the flat plate 1 during welding, but also enhances the welding effect. At the same time, the code-free foot assembly tool avoids welding temporary assembly corner codes during manufacturing, solves the problems of great difficulty, long cycle and high cost when removing the assembly corner codes, and avoids damage to the surface when removing the assembly corner codes, thereby ensuring the smooth and beautiful appearance of the outer surface of the main body segment 6.

[0142] In the present embodiment, the gap of the butt weld 100 is between 6mm and 8mm, and when the arc-shaped plate 2 and the second connecting structure 22 of the main body segment 6 are positioned and welded in step S43, it is ensured that the second connecting structure 22 is in full contact with the arc-shaped plate 2, and the gap therebetween is ≤0.2mm. Symmetrical intermittent welding is performed by using CO2 gas shielded welding, the welding material is E309MoL series stainless steel flux-cored wire, the purity of CO2 gas is ≥99.5%, the wire diameter is Φ1.2mm, the welding current is 180A-220A, the positioning welding length is 30mm-50mm, the positioning welding pitch is 300mm-500mm, and the size of the welding leg of the positioning welding is ≤80% of the designed welding leg size.

[0143] After the butt joint 100 between the planar plate 1 and the arc-shaped plate 2 of the main body segment 6 is leveled and fixed by using the code-free assembly tool, the butt joint 100 is welded by using the CO2 gas shielded welding assisted by the ceramic gasket, the single-sided welding and double-sided forming, the welding material is the 316L series stainless steel flux-cored wire, the CO2 gas purity is greater than or equal to 99.5%, the welding wire diameter is Φ1.2mm, the welding current of the weld backing layer is 160A-180A, the welding current of the other layers is 180A-210A, and the interlayer temperature of the weld is less than or equal to 150℃. The welding process is the same as the welding process of the butt joint 100 between the plurality of body segments 6.

[0144] In addition, when the butt joint 100 between the first connecting structure 12 and the second connecting structure 22 of the main body segment 6 is welded in step S46, the CO2 gas shielded welding is used for welding, the welding material is the E501T-1 series carbon steel flux-cored wire, the CO2 gas purity is greater than or equal to 99.5%, the welding wire diameter is Φ1.2mm, and the welding current is 190A-230A.

[0145] When the butt joint 100 between the arc-shaped plate 2 and the second connecting structure 22 is welded in step S47, the CO2 gas shielded welding is used for welding, the welding material is the E501T-1 series carbon steel flux-cored wire, the CO2 gas purity is greater than or equal to 99.5%, the welding wire diameter is Φ1.2mm, and the welding current is 190A-230A.

[0146] Specifically, as shown in Figure 6 、 Figure 9 、 Figures 13 to 15 , step S5 specifically includes the following steps:

[0147] Step S5 specifically includes the following steps:

[0148] S51, hoist the bottom segment 4 to the corresponding installation position, the installation position is connected with the third connecting structure corresponding to the first connecting structure 12 and the second connecting structure 22, and the first connecting structure 12 and the second connecting structure 22 on the bottom segment 4 are respectively welded and fixed with the corresponding third connecting structure;

[0149] S52, hoist the main body segment 6 to the upper side of the bottom segment 4, adjust the gap of the butt joint 100 between the main body segment 6 and the bottom segment 4, and then weld and fix the first connecting structure 12 and the second connecting structure 22 on the main body segment 6 with the corresponding third connecting structure;

[0150] S53, after the butt joint 100 between the main body segment 6 and the bottom segment 4 is leveled and fixed by using the code-free assembly tool, the butt joint 100 is welded;

[0151] S54, weld the butt weld 100 between the first connecting structure 12 on the main section 6 and the second connecting structure 22 on the bottom section 4;

[0152] S55, hoist the top section 5 above the main section 6 and adjust the gap between the top section 5 and the main section 6, and then weld and fix the first connecting structure 12 and the second connecting structure 22 on the top section 5 with the corresponding third connecting structures respectively;

[0153] S56, weld the butt weld 100 between the main section 6 and the top section 5 after positioning and leveling by the no-angle foot assembly tool;

[0154] S57, weld the butt weld 100 between the first connecting structure 12 on the main section 6 and the second connecting structure 22 on the top section 5;

[0155] S58, weld the external pipeline 7 in the connecting through hole.

[0156] By setting the third connecting structure corresponding to the first connecting structure 12 and the second connecting structure 22 at the installation position, the positioning and fixing of the bottom section 4, the main section 6 and the top section 5 are facilitated, and the gap of the butt weld 100 between the bottom section 4, the main section 6 and the top section 5 is ensured to be within the specified range. The no-angle foot assembly tool is used to level and fix the butt weld 100 between the bottom section 4, the main section 6 and the top section 5, which not only ensures the accuracy of the connecting position of the bottom section 4, the main section 6 and the top section 5 during welding, but also enhances the welding effect. At the same time, the no-angle foot assembly tool avoids welding temporary assembly corner codes during manufacturing, solves the problems of great difficulty, long cycle and high cost during the removal of the assembly corner codes, and avoids damage to the surface during the removal of the assembly corner codes, thereby ensuring the smooth and beautiful appearance of the fuel tank.

[0157] In the embodiment, in order to facilitate hoisting of the bottom segment 4, the main body segment 6 and the top segment 5, the first connecting structure 12 and the second connecting structure 22 on the bottom segment 4, the main body segment 6 and the top segment 5 are further provided with hoisting structures, for example, lifting lugs and the like, and the third connecting structure is also made of carbon steel, thereby facilitating welding of the third connecting structure with the first connecting structure 12 and the second connecting structure 22, the gap of the butt joint 100 is between 6 mm and 8 mm, after the butt joint 100 between the bottom segment 4, the main body segment 6 and the top segment 5 is leveled and fixed by using the code-free foot assembly tool, the butt joint 100 is welded by using CO2 gas shielded welding with ceramic gasket assistance, single-sided welding and double-sided forming, the welding material is 316L series stainless steel flux-cored wire, the purity of CO2 gas is greater than or equal to 99.5%, the diameter of the welding wire is Φ1.2 mm, the welding current of the base layer of the welding seam is 160 A-180 A, the welding current of other layers is 180 A-210 A, and the interlayer temperature of the welding seam is less than or equal to 150°C. The welding process is the same as the process of welding the butt joint 100 between the plurality of split body plates 11.

[0158] When welding the corresponding first connecting structure 12 and the second connecting structure 22 on the bottom segment 4, the main body segment 6 and the top segment 5, CO2 gas shielded welding is used for welding, the welding material is E501T-1 series carbon steel flux-cored wire, the purity of CO2 gas is greater than or equal to 99.5%, the diameter of the welding wire is Φ1.2 mm, and the welding current is 190 A-230 A.

[0159] In addition, the external pipeline 7 includes an access channel 71, an access pipeline 72 and an ejection pipeline 73.

[0160] Further, when welding the external pipeline 7 in the connecting through hole, the welding seam outside the fuel tank is welded first, and then the welding seam inside the fuel tank is welded. The welding seam inside the fuel tank is the last welding seam, which prevents the welding seam on the contact side of the methanol from being repeatedly heated by the subsequent welding seam and oxidized, and prevents the grain size of the metallographic structure of the welding seam inside the fuel tank from being coarse, thereby improving the corrosion resistance and mechanical properties of the welding seam inside the methanol tank.

[0161] It should be pointed out that, in the embodiment, all the butt joints 100 are welded by first welding the welding seam outside the fuel tank and then welding the welding seam inside the fuel tank.

[0162] Specifically, as shown in FIG. 6, the step S6 specifically includes the following steps: Figure 7

[0163] S61, cleaning and polishing each welding seam by using a polishing sheet;

[0164] S62, applying a special passivation paste to the welding seam inside the fuel tank to passivate the welding seam.​

[0165] S63, flushing the entire fuel tank with tap water.

[0166] By cleaning, polishing and passivating the welds, the corrosion resistance of the welds inside the fuel tank is enhanced, and the welds are prevented from being corroded and causing leakage.

[0167] Optionally, as shown in Figure 8 , Figure 15 The no-foot assembly tooling includes a clamping bolt, a tooling support, an insertion connecting plate, and a clamping leveling plate. The specific steps for leveling and fixing the butt weld 100 using the no-foot assembly tooling are as follows:

[0168] Step 1: A first insertion slot is formed on the insertion connecting plate. The tooling support is inserted into the first insertion slot, and the insertion connecting plate is inserted into the butt weld 100.

[0169] Step 2: A second insertion slot is formed on the insertion connecting plate. The clamping leveling plate is inserted into the second insertion slot, and the clamping leveling plate is abutted against the end faces of the components on both sides of the butt weld 100.

[0170] Step 3: A threaded hole is formed on the tooling support. The clamping bolt is inserted into the threaded hole. The clamping leveling plate is clamped against the end faces of the components on both sides of the butt weld 100 by tightening the clamping bolt. The end of the tooling support and the end of the clamping bolt are clamped against the upper surfaces of the components on both sides of the butt weld 100, respectively.

[0171] Using the above no-foot assembly tooling, leveling and fixing of the butt weld 100 can be achieved by simply screwing the clamping bolt. The operation is simple, effectively reducing the labor burden of the workers, and avoiding welding of temporary assembly corner codes during manufacturing. The problems of high difficulty, long cycle, and high cost in removing the assembly corner codes are solved. The damage to the surface when removing the assembly corner codes is avoided, and the smooth and beautiful appearance of the fuel tank is ensured.

[0172] In this embodiment, the no-foot assembly tooling further includes a pressing block. The clamping end of the clamping bolt is rotatably arranged in the pressing block. By rotatably arranging the clamping end of the clamping bolt in the pressing block, the pressing block does not rotate when the clamping bolt is screwed, effectively preventing the clamping end of the clamping bolt from rotating relative to the surface of the component and causing scratches on the surface of the component. Exemplarily, the pressing block is a spherical surface contact rotary connection structure.

[0173] As shown in Figure 9The embodiment also provides a fuel tank manufactured by the fuel tank manufacturing method of any one of the above. The fuel tank manufactured by the method has small stress concentration at edges and corners, and adopts the form of butt welds, so that the welding effect is more thorough, the sealing of the welds is good, the reliability is high, and the safety is strong. The fuel tank in the embodiment is a formaldehyde tank for storing formaldehyde in a ship.

[0174] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation modes of the present application. For those skilled in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present application. It is unnecessary and impossible to enumerate all the implementation modes here. Any modification, equivalent substitution and improvement within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for manufacturing a fuel tank, characterized in that, The fuel tank manufacturing method includes the following steps: S1, spare plates: According to the specifications of the fuel tank, make multiple flat plates (1), multiple curved plates (2) and multiple spherical plates (3); S2. Making the bottom segment (4): Weld the arc plate (2) to the four sides of the flat plate (1), and weld the spherical plate (3) between each two adjacent arc plates (2) to form the bottom segment (4); S3. Making the top section (5): Weld the arc plate (2) to the four sides of the flat plate (1), weld the spherical plate (3) between each two adjacent arc plates (2), and open a plurality of connecting through holes on the flat plate (1) for connecting with the external pipe (7) to form the top section (5). S4. Making the main body segment (6): The arc plate (2) is welded between each two adjacent planar plates (1) to form the main body segment (6); S5. Assembly and welding: The main body segment (6) is welded to the bottom segment (4) and the top segment (5) is welded to the main body segment (6) using a butt weld (100) joint. S6. Post-weld treatment: Clean the weld seams at each weld joint.

2. The fuel tank manufacturing method according to claim 1, characterized in that, Step S1 specifically includes the following steps: S11. The planar plate (1) includes multiple split plates (11) and a first connecting structure (12). The first connecting structure (12) is welded to corresponding positions on the multiple split plates (11) to form the planar plate (1). S12. The arc plate (2) includes an arc main board (21) and a second connecting structure (22). The second connecting structure (22) is welded to the corresponding position of the arc main board (21) to form the arc plate (2). S13. The spherical plate (3) is made of a spherical structure with the same radius as the arc plate (2) as the spherical plate (3).

3. The fuel tank manufacturing method according to claim 2, characterized in that, Step S11 specifically includes the following steps: S111. Welding grooves for the butt welds (100) facing the inside of the fuel tank are opened on the multiple split plates (11). The welding grooves of the multiple split plates (11) are facing down and laid flat on the assembly bracket. The first connecting structure (12) is positioned and welded to the corresponding position on the split plate (11). S112. Starting from the middle split plate (11), proceed symmetrically towards both ends to complete the perimeter sealing weld of the fillet weld between the first connecting structure (12) and the split plate (11). S113. After completing the perimeter sealing welding of the first connecting structure (12) and the split plate (11), flip the split plate (11) so that the welding groove of the butt weld (100) faces upward. S114. The butt welds (100) between the multiple split plates (11) are leveled and fixed using the footless assembly fixture, and the butt welds (100) between the multiple split plates (11) outside the area where the footless assembly fixture is located are welded. S115. Remove the mounting fixture without the code foot and perform continuous welding on the butt weld (100) between the multiple split plates (11).

4. The fuel tank manufacturing method according to claim 2, characterized in that, Step S2 specifically includes the following steps: S21. Place the flat plate (1) with the inner surface of the compartment facing upward on the assembly bracket; S22, the second connecting structure (22) is fixed to the first connecting structure (12) on the flat plate (1) by positioning welding, and the outer side of the second connecting structure (22) is temporarily fixed to the assembly bracket by welding; S23. Adjust the gap of the butt weld (100) between the arc plate (2) and the flat plate (1), and fix the arc plate (2) to the second connecting structure (22) by positioning weld; S24. Adjust the gap between the spherical plate (3) and the arc plate (2), and use a footless assembly tool to level and fix the butt weld (100) between the spherical plate (3) and the arc plate (2) and the butt weld (100) between the flat plate (1) and the arc plate (2); S25. Weld the butt weld (100) between the spherical plate (3) and the arc plate (2) and the butt weld (100) between the flat plate (1) and the arc plate (2); S26. Weld the butt weld (100) between the first connecting structure (12) and the second connecting structure (22); S27. Weld the fillet weld between the second connecting structure (22) and the arc plate (2).

5. The fuel tank manufacturing method according to claim 2, characterized in that, Step S4 specifically includes the following steps: S41. The flat plate (1) is placed vertically on the assembly bracket and temporarily welded to the assembly bracket through the first connecting structure (12); S42. Fix the second connecting structure (22) at the corresponding position of the assembly bracket and fix it with the corresponding first connecting structure (12) by positioning welding; S43. Adjust the gap between the arc plate (2) and the flat plate (1) of the butt weld (100), and fix the arc plate (2) to the second connection structure (22) by positioning weld; S44. The butt weld (100) between the arc plate (2) and the flat plate (1) is leveled and fixed using a footless assembly fixture; S45. Weld the butt weld (100) between the arc plate (2) and the flat plate (1); S46. Weld the butt weld (100) between the second connecting structure (22) and the first connecting structure (12); S47. Weld the arc plate (2) to the fillet weld of the second connecting structure (22).

6. The fuel tank manufacturing method according to claim 2, characterized in that, Step S5 specifically includes the following steps: S51. Hoist the bottom segment (4) to the corresponding installation position. The installation position is connected to a third connection structure corresponding to the first connection structure (12) and the second connection structure (22). Weld the first connection structure (12) and the second connection structure (22) on the bottom segment (4) to the corresponding third connection structure respectively. S52. Hoist the main body segment (6) above the bottom segment (4) and adjust the gap of the butt weld (100) between the main body segment (6) and the bottom segment (4). Then, weld and fix the first connecting structure (12) and the second connecting structure (22) on the main body segment (6) to the corresponding third connecting structure respectively. S53. The butt weld (100) between the main body segment (6) and the bottom segment (4) is positioned and leveled using a non-clamping assembly tool before welding. S54. Weld the butt weld (100) between the first connecting structure (12) on the main body segment (6) and the second connecting structure (22) on the bottom segment (4); S55. Hoist the top segment (5) above the main body segment (6) and adjust the gap between the top segment (5) and the main body segment (6). Then weld and fix the first connecting structure (12) and the second connecting structure (22) on the top segment (5) to the corresponding third connecting structure respectively. S56. The butt weld (100) between the main body segment (6) and the top segment (5) is positioned and leveled using the mounting fixture without mounting brackets and then welded. S57. Weld the butt weld (100) between the first connecting structure (12) on the main body segment (6) and the second connecting structure (22) on the top segment (5); S58. Weld the external pipe (7) into the connecting through hole.

7. The fuel tank manufacturing method according to claim 6, characterized in that, When welding the external pipe (7) into the connecting through hole, weld the weld on the outside of the fuel tank first, and then weld the weld inside the fuel tank.

8. The fuel tank manufacturing method according to claim 1, characterized in that, Step S6 specifically includes the following steps: S61. Use a polishing pad to clean and polish each weld seam. S62. Apply a special passivation paste to the weld seams inside the fuel tank to passivate the weld seams. S63. Rinse the entire fuel tank with tap water.

9. The method for manufacturing a fuel tank according to any one of claims 3-6, characterized in that, The clamp-free assembly fixture includes clamping bolts, a fixture bracket, an insertion connecting plate, and a clamping leveling plate. The specific steps for leveling and fixing the butt weld (100) using the clamp-free assembly fixture are as follows: Step 1: The insertion connecting plate has a first slot. The tooling bracket is inserted into the first slot, and the insertion connecting plate is inserted into the butt weld (100). Step 2: The insertion connecting plate has a second slot. The clamping and calibrating plate is inserted into the second slot and the clamping and calibrating plate abuts against the end faces of the components on both sides of the butt weld (100). Step 3: The tooling bracket has a threaded hole. The clamping bolt is inserted into the threaded hole. By tightening the clamping bolt, the clamping plate presses the end faces of the components on both sides of the butt weld (100). At the same time, the ends of the tooling bracket and the clamping bolt press the upper surfaces of the components on both sides of the butt weld (100).

10. A fuel tank, characterized in that, The fuel tank is manufactured by the fuel tank manufacturing method as described in any one of claims 1-9.

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