Manufacturing method of air rail track beam box and air rail track beam

Abstract

The invention belongs to the technical field of rail transit, and particularly relates to a manufacturing method of an air rail track beam box and an air rail track beam. The manufacturing method comprises the following steps: determining key control points of a horizontal curve and a vertical curve through three-dimensional lofting; erecting a total splicing jig frame according to the coordinates of the control points; laying separated bottom plates and webs on the general splicing jig frame to form a groove-shaped structure, and connecting the bottom plates by using a temporary bridging structure; a latch plate is assembled and welded in the groove-shaped structure; the top plate is assembled to seal the opening, and welding seams between the plates are welded; after finishing and inspecting, assembling and welding outer reinforcing ribs which are prefabricated in sections on the outer surface of the box body; after the box body is turned over by 180 degrees, welding of the external stiffening ribs and the bottom plate is completed; bottom plate longitudinal ribs are assembled and welded; and the temporary bridging structure is cut off, and constraint is released. According to the method, the space linear precision is guaranteed through the total splicing jig frame, the stability of the welding process is enhanced through the temporary bridging structure, deformation and residual stress are effectively controlled through the symmetrical welding sequence, and therefore the high-precision and high-strength curve type track beam box is efficiently manufactured.

Description

Technical Field

[0001] This invention belongs to the field of rail transit technology, specifically a method for manufacturing a box girder for an air rail system and an air rail girder. Background Technology

[0002] Skyrail transit, as an emerging mode of public transportation, is currently experiencing rapid development in China. Its simple structure and relatively low construction cost have demonstrated promising application prospects in urban transportation systems. Furthermore, skyrail's small turning radius allows it to better adapt to complex urban terrain and road conditions, enhancing the flexibility and coverage of route planning. The core load-bearing component of an aerial rail transit system is the track beam, especially the curved sections located at line bends. These track beams have complex structures, typically large, fully welded steel box-type structures, and simultaneously possess horizontal curves and vertical camber, thus requiring extremely high manufacturing precision.

[0003] In existing technologies, the manufacturing of large steel box girders typically employs jigs to ensure the final alignment and dimensions. For example, a "reverse assembly method" is used, where the top and web plates are first assembled on the jig to form an inverted, relatively stable closed or semi-closed structure, and then other components are welded sequentially. This method provides good structural rigidity and easy deformation control in the early stages of processing. However, for certain specific structures, the "direct assembly method" may be more advantageous in operation. The "direct assembly method" refers to assembling the bottom and web plates first to form an upward-opening channel-shaped structure. However, the inherent drawback of the "direct assembly method" is that the initially formed open channel-shaped structure has poor rigidity and insufficient stability. Under the subsequent large amount of welding heat input, it is prone to uncontrollable deformations such as torsion and tilting, severely affecting the final dimensional accuracy and structural stability of the track beam. Furthermore, the existing design's overall external stiffening ribs are heavy, difficult to hoist, and have limited construction space when welding them together, severely impacting assembly efficiency and on-site construction. In addition, since the enclosure is a fully welded structure with a large number of welds and a complex distribution, if the welding sequence, beveling form or constraint method is not appropriate, uncontrollable welding deformation and large residual stress can easily occur, which will affect the structural geometric accuracy, fatigue performance and long-term service safety.

[0004] Therefore, there is an urgent need for an innovative method for manufacturing the box girder of the air rail, which can achieve standardized production with high precision, high efficiency, and low deformation while ensuring structural strength, so as to promote the overall progress and engineering application of air rail technology. Summary of the Invention

[0005] The purpose of this invention is to provide a manufacturing method for an air track beam box and an air track beam box, so as to solve the technical problem that it is difficult to control welding deformation when manufacturing an air track beam box with complex spatial curves using the positive mounting method in the prior art due to insufficient rigidity of the initial open slot structure.

[0006] The first objective of this invention is to provide a method for manufacturing a box girder for an air track, comprising the following steps:

[0007] Step S1: Perform three-dimensional layout of the box to be manufactured, determine the coordinates of key control points on its horizontal and vertical curves, and draw construction drawings;

[0008] Step S2: Based on the coordinates of the key control points in Step S1, construct the overall assembly frame on the reference platform; the overall assembly frame includes multiple columns arranged along the length of the box body, as well as a bottom plate support plate and a web plate limiting plate set on the columns;

[0009] Step S3: Lay the two separate bottom plates on the bottom plate support plate respectively, and lay the two web plates on the corresponding web plate limiting plates respectively. The bottom plates and web plates form an upward-opening groove structure; and use a temporary bridging structure to connect the two separate bottom plates into one piece.

[0010] Step S4: Position and assemble the latch plate that divides the box space inside the groove structure, and weld the web plate to the upper corner weld of the latch plate;

[0011] Step S5: Assemble the top plate at the top opening of the channel structure to close the top opening of the channel structure, and weld the connecting welds between the web and the top plate, between the web and the bottom plate, and between the web and the latch plate.

[0012] Step S6: After repairing and inspecting each weld of the box body, position and assemble multiple sets of spaced external stiffening ribs on the outer surface of the box body along the length of the box body, and weld the butt welds between each set of external stiffening ribs and the fillet welds between them and the top plate and web plate.

[0013] Step S7: Rotate the box body 180° and weld the fillet weld between the external stiffening rib and the bottom plate;

[0014] Step S8: Assemble the longitudinal ribs of the base plate and weld them to the base plate;

[0015] Step S9: Remove the temporary bridging structure from step S3 to release the constraint between the two base plates.

[0016] Furthermore, in step S2: the upper edge of the bottom plate support plate is spatially positioned according to the linear design of the box body to form the required horizontal curve and longitudinal slope. The spacing of the web plate limiting plate is set along the length direction of the box body according to the design of the external stiffening ribs.

[0017] Furthermore, during the welding process of the box body, the welding sequence follows the principle of symmetrical segmented welding from the middle of the welding area to both ends, and parallel welding is adopted.

[0018] Furthermore, in step S3, an angle fixing plate is provided at the inner angle between the web plate and the bottom plate, and the angle fixing plate is fixed to the web plate and the bottom plate respectively by positioning welding, so as to realize the spatial angle positioning of the web plate relative to the bottom plate.

[0019] Furthermore, in step S6, each group of external stiffeners is prefabricated into 3 to 5 segmented units;

[0020] During assembly, a 2-5mm assembly gap is reserved between adjacent segment units. After assembly and positioning, butt welds are applied at the assembly gaps between adjacent segment units to connect the segment units into a whole.

[0021] Furthermore, after step S9, step S10 is also included: end face machining of both ends of the housing to form a flat assembly reference plane, and welding end support plates and pin guard plates to the machined ends, determining the center position of the pin holes at both ends, and machining to form pin holes.

[0022] Furthermore, in step S3, the bottom plate and the web plate are tightly fitted to the bottom plate support plate and the web plate limiting plate, respectively, and then welded and fixed.

[0023] In step S6, the external stiffeners are tightly attached to the web and welded together for fixation.

[0024] Furthermore, in step S9, after the temporary bridging structure is removed, the box in its free state is subjected to line detection; the line detection includes at least the measurement of the camber of the horizontal curve and the vertical curve;

[0025] The measurement results will determine whether the design requirements are met. If not, the enclosure will be modified.

[0026] The second objective of this invention is to provide a box girder for an air track, manufactured using any of the methods described above. The box girder has a box-shaped cross-section with an open bottom. The box girder includes: a pair of separate bottom plates; a pair of web plates, respectively connected and fixed to the bottom plates, the bottom plates and web plates forming a channel-shaped structure; a latch plate fixed inside the channel-shaped structure, dividing the internal space into an upper space and a lower space; and a top plate fixed at the top opening of the channel-shaped structure to close the upper space. The box girder has a spatial curve linearity adapted to its preset route.

[0027] Furthermore, the outer side of the web plate is provided with multiple sets of external stiffening ribs arranged at intervals along the length of the box body, and the outer side of the bottom plate is provided with bottom plate longitudinal ribs extending along the length of the box body.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) This application provides a precise three-dimensional spatial reference for the entire manufacturing process by using a special assembly jig customized based on the parameters of horizontal and vertical curves, which fundamentally ensures the geometric accuracy of the complex spatial curves of the final product. This method innovatively introduces a temporary bridging structure reinforcement measure in the positive assembly process, which effectively overcomes the inherent defect of insufficient rigidity of the initial open slot structure, significantly enhances the stability of the workpiece during the welding process, and thus effectively suppresses welding deformation.

[0030] (2) The welding sequence is symmetrical from the middle to both ends, which makes the welding heat input and shrinkage stress more evenly distributed throughout the structure, minimizing the overall welding deformation and internal residual stress of the beam, and ensuring the structural strength and long-term stability. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a structural diagram of a general assembly frame erected on a reference platform according to an embodiment of the present invention;

[0033] Figure 2 for Figure 1 Assembly structure diagram of the columns, base plate support plate and web plate support plate;

[0034] Figure 3 An embodiment of the present invention provides for mounting a base plate and a web plate on a complete assembly frame;

[0035] Figure 4 This is an assembly structure diagram of the base plate and bridging structure provided in an embodiment of the present invention;

[0036] Figure 5 A latch plate is installed on the web plate according to an embodiment of the present invention;

[0037] Figure 6 An embodiment of the present invention provides a top plate mounted above a latch plate;

[0038] Figure 7 This invention provides an embodiment of positioning and assembling external stiffening ribs on the outside of the housing;

[0039] Figure 8 This is another angle view of the external stiffening ribs being positioned and assembled on the outside of the housing, according to an embodiment of the present invention.

[0040] Figure 9 This is a segmented structural diagram of an external stiffener provided in an embodiment of the present invention;

[0041] Figure 10 A top view of the air track beam box body is provided for one embodiment of the present invention;

[0042] Figure 11 A side view structural schematic diagram of the air track beam box body is provided for one embodiment of the present invention;

[0043] Figure 12 This is a cross-sectional schematic diagram of an empty track box provided in an embodiment of the present invention;

[0044] Wherein: 10-bottom plate; 20-web plate; 30-bridging structure; 40-latch plate; 50-top plate; 60-external stiffening rib; 70-bottom plate longitudinal rib; 100-general assembly frame; 110-column; 120-bottom plate support plate; 130-web plate limiting plate; 140-reference platform; B-reference end. Detailed Implementation

[0045] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0046] The following is in conjunction with the appendix Figure 1 To be continued Figure 12 The invention is described in detail with specific embodiments.

[0047] Before detailing the specific technical solution of this application, a brief description of the main structural forms of the track beam box body is provided. Currently, the main body of the monorail track beam primarily adopts a box-shaped open-bottom cross-section and a box-shaped closed-top cross-section. Track beams can be classified into straight track beams and curved track beams according to their alignment. Among them, curved track beams have a more complex structural form due to the need to adapt to the changes in horizontal and vertical curves of the track. Specifically, curved track beams do not have a uniform cross-section throughout their entire length; their cross-sectional height gradually increases from specific positions at both ends towards the mid-span, eventually transitioning and stabilizing into upper and lower box-shaped cross-sections with constant dimensions. This spatial variable cross-section characteristic places extremely high demands on manufacturing precision, forming control, and component assembly. The technical improvements in this application are precisely aimed at addressing the practical difficulties faced in the manufacturing process of such curved track beams.

[0048] See Figures 1 to 7 This invention provides a method for manufacturing a box girder of an air track. The method adopts the positive assembly method and combines it with special forming tooling, process stability measures and stress control strategies to systematically solve the problem of deformation suppression during the manufacturing process of a box girder with complex spatial curves.

[0049] Figure 10 and Figure 11 This illustration shows the track beam box girder manufactured in this embodiment, which serves as a key load-bearing component in an aerial rail transit system. Figure 10 As can be seen from the top view, the track beam box girder appears as a horizontal curve when viewed from above, while when viewed from the side, it has an upward-protruding vertical camber (e.g., Figure 11 This complex three-dimensional spatial form, with both horizontal and vertical curves coexisting, places extremely high demands on its manufacturing precision. The track beam box of this application is mainly composed of a box body, external stiffening ribs arranged at intervals along the length direction, and end connection structures for segment splicing, presenting an overall large-scale fully welded steel structure.

[0050] The manufacturing method provided in this application includes the following steps:

[0051] Step S1: Perform three-dimensional layout of the box girder to be manufactured, determine the coordinates of key control points on its horizontal and vertical curves, and draw construction drawings. Specifically, this step uses professional engineering software to create a three-dimensional digital model of the track beam box girder based on the line design parameters provided by the design institute. On this model, accurately extract the horizontal curve coordinates and vertical camber elevation of each key section position along the length of the box girder. Subsequently, based on these precise coordinate data, generate detailed construction drawings, and cut and arrange all the plates constituting the box girder (including bottom plate 10, web plate 20, latch plate 40, top plate 50, etc.), while reserving reasonable machining allowances (e.g., 3-5mm) for subsequent finishing and welding shrinkage.

[0052] Step S2: Refer to Figure 1 and Figure 2 Based on the coordinates of the key control points in step S1, a general assembly frame 100 is erected on the reference platform 140. This general assembly frame 100 is the core tooling to ensure the final alignment accuracy of the enclosure, and it is erected on a reference surface platform that has been precisely leveled. The general assembly frame 100 includes multiple columns 110 arranged at predetermined intervals along the length of the enclosure, and a base plate support plate 120 and a web plate limiting plate 130 set on the columns 110. It can be understood that the upper edge of the base plate support plate 120 needs to be spatially positioned according to the alignment design of the enclosure to form the required horizontal curve and longitudinal slope. The web plate limiting plate 130 is spatially positioned according to the horizontal curve coordinates of the enclosure, and its inner surface provides a precise horizontal positioning reference for the subsequent installation of the web plate 20. Specifically, the web plate limiting plate 130 is spaced along the length of the enclosure according to the design placement of the stiffening ribs 60. In this way, the entire general assembly frame 100 provides a precise and reliable spatial reference for the assembly of the enclosure. Furthermore, the overall assembly of each plate unit is carried out on the main assembly frame with reference end B.

[0053] Step S3: Refer to Figure 3 and Figure 4 Two separate base plates 10 are laid on the base plate support plate 120, and two web plates 20 are laid on the corresponding web plate limiting plates 130. The base plates 10 and web plates 20 form an upward-opening groove structure. This step is the initial stage of the "direct assembly method". During operation, the two base plates 10 of the same thickness are hoisted onto the general assembly jig 100, so that their lower surfaces are completely in contact with the upper surfaces of the base plate support plate 120. Subsequently, the web plates 20 on both sides are hoisted into place, so that their outer surfaces are tightly in contact with the positioning surfaces of the web plate limiting plates 130, thereby initially forming an upward-opening U-shaped groove structure. It should be noted that because this open structure has poor rigidity, it is very easy to deform under the subsequent welding heat input. Therefore, this embodiment adopts key temporary reinforcement measures. Specifically, several temporary bridging structures 30 (for example, steel plates of the same thickness as the base plates can be used as bridging structures) are welded at intervals along the length between the two separate base plates 10, and are firmly welded to the inner edges of the two base plates 10, thereby temporarily connecting the two separate base plates 10 into a whole, significantly enhancing the lateral stiffness of the channel structure. Through the action of the bridging structures 30, the originally insufficiently stiff open channel structure is transformed into a stable and reliable semi-finished product to be processed.

[0054] Step S4: Refer to Figure 5The latch plate 40, which separates the box space, is positioned and assembled inside the channel structure. Specifically, the latch plate 40 of a certain thickness is hoisted into the channel structure and precisely positioned according to the drawing requirements. After positioning, the web plate 20 is welded to the upper corner weld of the latch plate 40, laying the foundation for the formation of the top closed box.

[0055] Step S5: Refer to Figure 6 A top plate 50 is assembled at the top opening of the channel structure to close the top opening, and connecting welds are welded between the web plate 20 and the top plate 50, between the web plate 20 and the bottom plate 10, and between the web plate 20 and the latch plate 40. Specifically, the top plate 50 is hoisted and placed over the web plate 20 and the latch plate 40, precisely positioned, and then spot-welded for fixation. Subsequently, the main welds are welded, including the fillet welds between the web plate 20 and the top plate 50, the fillet welds between the web plate 20 and the bottom plate 10, and the fillet welds on the outer (lower) side of the web plate 20 and the latch plate 40. To maximize the control of welding deformation and residual stress, all long main welds in this embodiment are welded in strict accordance with a key stress control principle: starting from the middle of the weld length, welding is carried out in segments and symmetrically towards both ends of the weld. In addition, the welding process should use parallel welding as much as possible to ensure good weld formation and uniform penetration depth. Through this symmetrical segmented welding strategy, the heat input and shrinkage stress generated by welding can be evenly distributed and offset throughout the entire box structure, thereby effectively reducing the overall bending and torsional deformation of the beam.

[0056] Step S6: Refer to Figure 7 and Figure 8 After repairing and inspecting all welds on the box body, multiple sets of spaced external stiffening ribs 60 are positioned and assembled along the length of the box body on its outer surface. The butt welds between each set of external stiffening ribs 60 and the fillet welds between them and the top plate 50 and the web plate 20 are then welded. Specifically, after the main welds are completed and confirmed to be of acceptable quality through non-destructive testing, the external stiffening ribs 60 are assembled. Each external stiffening rib 60 is tightly fitted to the outer surface of the web plate 20, ensuring its position and perpendicularity meet the drawing requirements. Subsequently, the butt welds between each set of external stiffening ribs 60 and the fillet welds between the external stiffening ribs 60 and the top plate 50 and the web plate 20 are welded. The welding here also follows the principle of symmetrical segmented welding from the middle to both ends.

[0057] Step S7: Rotate the enclosure 180° and weld the fillet weld between the external stiffening rib 60 and the base plate 10. In this step, use a large crane or specialized rotating equipment to smoothly rotate the enclosure 180 degrees so that its bottom faces upward. This transforms the previously difficult-to-reach connection between the external stiffening rib 60 and the base plate 10 into a convenient flat weld or stern weld location. Then, complete the fillet weld at this location using a symmetrical segmented welding method.

[0058] Step S8: Refer to Figure 12 Assemble the base plate longitudinal ribs 70 and weld the base plate longitudinal ribs 70 to the base plate 10. It is understandable that, since the base plate 10 itself has an arched curve, the base plate longitudinal ribs 70 need to be modified before assembly so that their shape can accurately match the curved surface of the base plate. Welding is then carried out after assembly and positioning.

[0059] Step S9: Remove the temporary bridging structure 30 from Step S3 to release the constraint between the two base plates 10. After all major structural welds are completed, carefully remove the bridging structure 30, which was previously welded for temporary reinforcement, using carbon arc gouging or flame cutting, and grind the cut smooth. At this point, the temporary constraint applied between the two base plates 10 is released, and the box girder is in a free state. High-precision measuring equipment such as a laser tracker can then be used to perform a final alignment check on the box girder in its free state to confirm whether its horizontal curve and vertical camber are within the design tolerance range. If deviations are found, flame straightening or other methods can be used for correction until it meets the requirements. By completing all the above manufacturing steps, the resulting track beam box girder is not only structurally complete, but its complex spatial alignment is also precisely controlled, and welding deformation and residual stress are minimized, thus providing a reliable guarantee for subsequent on-site installation and the smooth splicing of multiple beam segments.

[0060] It is worth reiterating that during the welding process of the box body, the welding sequence follows the principle of symmetrical segmented welding from the middle of the welding area to both ends, and parallel welding is used. The above welding method can reduce deformation and internal stress.

[0061] In a preferred embodiment, in step S3, an angle fixing plate (not shown in the figure) is provided at the inner angle between the web plate 20 and the base plate 10, and the angle fixing plate is fixed to the web plate 20 and the base plate 10 respectively by tack welding to achieve spatial angular positioning of the web plate 20 relative to the base plate 10. This angle fixing plate is typically a triangular steel plate, which is connected to the inner surfaces of the web plate 20 and the base plate 10 respectively by tack welding. Its function is to precisely control and lock the angle between the web plate 20 and the base plate 10 to prevent angle changes in subsequent processes.

[0062] In some embodiments, in step S6, each set of external stiffeners 60 is prefabricated into 3 to 5 segmented units. This segmented form facilitates fine-tuning and positioning of each unit on the overall assembly frame 100 according to the actual shape of the box body. The reserved assembly gap provides tolerance space for on-site adjustments, ensuring that the external stiffeners 60 can tightly fit the curved surface of the box body. Finally, they are welded together to form a whole. While ensuring structural continuity and rigidity, this significantly reduces the internal stress caused by forced assembly and effectively controls welding deformation, thereby ensuring the accuracy of the final track beam's shape and structural quality. Specifically, the external stiffeners 60 are prefabricated into 3 segments, such as... Figure 9 As shown, during assembly, a 2-5mm assembly gap is reserved between adjacent segment units. After assembly and positioning, butt welds are applied at the assembly gaps between adjacent segment units to connect the segment units into a whole.

[0063] Furthermore, after step S9, step S10 is included: end face machining of both ends of the box body to form a flat assembly reference plane, ensuring the smoothness and linear continuity when multiple track beams are connected, and welding end support plates and pin guard plates (not shown in the figure) to the machined ends, determining the center position of the pin holes at both ends, and machining the pin holes to ensure a reliable and precise mechanical connection between the track beam and the support or adjacent beam segments, thereby fully meeting the requirements of the air rail system for interface accuracy, structural strength and long-term operational safety.

[0064] Furthermore, in step S3, the base plate 10 and the web plate 20 are tightly fitted to the base plate support plate 120 and the web plate limiting plate 130, respectively, and are welded and fixed; in step S6, the external stiffening rib 60 is tightly fitted to the web plate 20 and welded and fixed.

[0065] Furthermore, in step S9, after the temporary bridging structure 30 is removed, the box body in its free state undergoes a linearity test. This linearity test includes at least the measurement of the camber of horizontal and vertical curves. Based on the measurement results, it is determined whether the design requirements are met. If not, the box body is corrected. This proactively eliminates deviations accumulated during manufacturing, ensuring that the box body's linearity fully conforms to the preset spatial curve design requirements, fundamentally guaranteeing the installation accuracy, smoothness, and operational safety of the track beam.

[0066] Furthermore, in step S8, the longitudinal rib 70 of the bottom plate is a bevel weld along its entire length, and the end face of it is a corner joint with the track beam box body. After welding, it needs to be ground smooth. In addition, the longitudinal rib 70 of the bottom plate also has curvature in the horizontal and vertical curve directions, which needs to be flame corrected before assembly to meet the requirements of the alignment.

[0067] See Figure 12The present invention also provides a box girder for an air track, manufactured using any of the methods described above. The box girder has a box-shaped cross-section with an open bottom. The box girder includes: a pair of separate bottom plates 10; a pair of web plates 20, respectively connected and fixed to each of the bottom plates 10, the bottom plates 10 and the web plates 20 together forming a channel-shaped structure; a latch plate 40, fixed inside the channel-shaped structure, dividing the internal space into an upper space and a lower space; and a top plate 50, fixed at the top opening of the channel-shaped structure, for closing the upper space. The box girder has a spatial curve linearity adapted to its preset route.

[0068] Furthermore, the outer side of the web plate 20 is provided with multiple sets of external stiffening ribs 60 arranged at intervals along the length of the box body, and the outer side of the bottom plate 10 is provided with bottom plate longitudinal ribs 70 extending along the length of the box body.

[0069] Specifically, the cross-sectional dimensions of the track beam box girder can be set as follows: net beam height of 1100mm (from the bottom of the top plate to the rail surface) and width of 780mm (net distance between web plates). The box girder adopts a bottom-opening composite cross-section, wherein its bottom plate 10 is composed of two 30mm thick steel plates, which also serve as the running surface for the monorail vehicle. Inside the box girder, a 22mm thick latch plate 40 is provided, which, together with the top plate 50 and the web plate 20, forms a closed box with a net height of 350mm and a net width of 780mm. This structure is used to significantly enhance the torsional stiffness of the entire beam. On the outside of the box girder, external stiffening ribs 60 with a thickness of 30mm and a width of 160mm are provided. Correspondingly, below the bottom plate 10, a bottom plate longitudinal rib 70 with a thickness of 40mm and a height of 80mm is also provided.

[0070] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the nature and scope of the present invention. Various modifications made to the above embodiments by those skilled in the art after reading this specification are all within the scope of protection of the present invention.

Claims

1. A method for manufacturing a box girder for an air-rail system, characterized in that, Includes the following steps: Step S1: Perform three-dimensional layout of the box to be manufactured, determine the coordinates of key control points on its horizontal and vertical curves, and draw construction drawings; Step S2: Based on the coordinates of the key control points in Step S1, construct the overall assembly frame on the reference platform; the overall assembly frame includes multiple columns arranged along the length of the box body, as well as a bottom plate support plate and a web plate limiting plate set on the columns; Step S3: Lay the two separate bottom plates on the bottom plate support plate respectively, and lay the two web plates on the corresponding web plate limiting plates respectively. The bottom plates and web plates form an upward-opening groove structure; and use a temporary bridging structure to connect the two separate bottom plates into one piece. Step S4: Position and assemble the latch plate that divides the box space inside the groove structure, and weld the web plate to the upper corner weld of the latch plate; Step S5: Assemble the top plate at the top opening of the channel structure to close the top opening of the channel structure, and weld the connecting welds between the web and the top plate, between the web and the bottom plate, and between the web and the latch plate. Step S6: After repairing and inspecting each weld of the box body, position and assemble multiple sets of spaced external stiffening ribs on the outer surface of the box body along the length of the box body, and weld the butt welds between each set of external stiffening ribs and the fillet welds between them and the top plate and web plate. Step S7: Rotate the box body 180° and weld the fillet weld between the external stiffening rib and the bottom plate; Step S8: Assemble the longitudinal ribs of the base plate and weld them to the base plate; Step S9: Remove the temporary bridging structure from step S3 to release the constraint between the two base plates.

2. The method for manufacturing the air track beam box body according to claim 1, characterized in that, In step S2: the upper edge of the bottom plate support plate is spatially positioned according to the linear design of the box body to form the required horizontal curve and longitudinal slope; the web plate limiting plate is spaced according to the design of the external stiffening ribs along the length direction of the box body.

3. The method for manufacturing the air track beam box body according to claim 1, characterized in that, During the welding process of the box body, the welding sequence follows the principle of symmetrical segmented welding from the middle of the welding area to both ends, and parallel welding is adopted.

4. The method for manufacturing the air track beam box body according to claim 1, characterized in that, In step S3, an angle fixing plate is set at the inner angle between the web plate and the bottom plate, and the angle fixing plate is fixed to the web plate and the bottom plate respectively by positioning welding, so as to realize the spatial angle positioning of the web plate relative to the bottom plate.

5. The method for manufacturing the air track beam box body according to claim 1, characterized in that, In step S6, each set of external stiffeners is prefabricated into 3 to 5 segmented units; During assembly, a 2-5mm assembly gap is reserved between adjacent segment units. After assembly and positioning, butt welds are applied at the assembly gaps between adjacent segment units to connect the segment units into a whole.

6. The method for manufacturing the air track beam box body according to claim 1, characterized in that, After step S9, step S10 is also included: end face machining of both ends of the housing to form a flat assembly reference plane, and welding end support plates and pin guard plates to the machined ends, determining the center position of the pin holes at both ends, and machining the pin holes.

7. The method for manufacturing the air track beam box body according to claim 1, characterized in that, In step S3, the bottom plate and the web plate are tightly fitted to the bottom plate support plate and the web plate limiting plate, respectively, and then welded and fixed. In step S6, the external stiffeners are tightly attached to the web and welded together for fixation.

8. The method for manufacturing the air track beam box body according to claim 1, characterized in that, In step S9, after the temporary bridging structure is removed, the box in its free state is subjected to line detection; the line detection includes at least the measurement of the camber of the horizontal curve and the vertical curve; The measurement results will determine whether the design requirements are met. If not, the enclosure will be modified.

9. A box girder for an empty track, characterized in that, Manufactured using the method described in any one of claims 1-8, the box body has a box-shaped cross-section with a bottom opening, and the box body comprises: A pair of separate base plates; A pair of web plates are respectively connected and fixed to each of the bottom plates, and the bottom plates and web plates together form a groove-shaped structure; A latch plate is fixed inside the groove structure and divides the internal space into an upper space and a lower space; A top plate is fixed to the top opening of the groove structure to enclose the upper space; The enclosure has a spatial curve linearity adapted to its preset circuit.

10. The air track beam box body according to claim 9, characterized in that, The outer side of the web plate is provided with multiple sets of external stiffening ribs arranged at intervals along the length of the box body, and the outer side of the bottom plate is provided with bottom plate longitudinal ribs extending along the length of the box body.

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