Modular steel box girder hoisting system dedicated to limited space

Abstract

This invention relates to a modular steel box girder hoisting system specifically designed for confined spaces. It includes a tractor unit, two hoisting modules, and a transport module. Each hoisting module comprises a first vehicle body and a crane mounted on the first vehicle body. The transport module includes a second vehicle body, which is a flatbed trailer with a support surface on top to support the steel box girder. Linkage joints are provided between the tractor unit and the first vehicle body, between the tractor unit and the second vehicle body, and between the first and second vehicle bodies to enable their linkage. Interconnectable linkage joints are also provided at the front and rear ends of the first and second vehicle bodies. Support devices are provided on the left and right sides of both the first and second vehicle bodies to keep them stationary. Using this design, the invention provides a highly efficient modular steel box girder hoisting system specifically designed for confined spaces.

Description

Technical Field

[0001] This invention relates to the field of bridge construction equipment, and more specifically to a modular steel box girder hoisting system designed for use in confined spaces. Background Technology

[0002] During bridge construction, it is common to encounter high-voltage power lines passing overhead. These lines can be 110KV, 220KV, or 350KV, and are typically about 12 meters above the ground. According to the "Technical Specification for Temporary Power Supply Safety at Construction Sites," the minimum safe distance between lifting machinery and the edge of overhead power lines is 5-7 meters. This leaves only 7-5 meters of effective safe space for the lifting machinery to operate. When hoisting the steel box girder of the superstructure bridge, the weight of a segment is typically 20-40 tons. If a truck crane is used, the effective space required is 15-22 meters. Therefore, under these special conditions, it is impossible to use a truck crane to complete the hoisting of the steel box girder.

[0003] To address the aforementioned issues, a solution has emerged that involves using a gantry crane to erect and load the beams, a flatbed truck to move and feed the beams, and a temporary Bailey bridge assembly machine to complete the hoisting and positioning of the steel box girder. This method is time-consuming, costly, and carries significant safety risks. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a modular steel box girder hoisting system for efficient construction in limited spaces.

[0005] To achieve the above objectives, the present invention provides the following technical solution: It includes a tractor unit, characterized in that it further includes two lifting modules and a transport module. The lifting module includes a first vehicle body and a crane mounted on the first vehicle body. The transport module includes a second vehicle body, which is a flatbed trailer. The flatbed trailer has a support surface on top that supports a steel box girder. Linkage joints are provided between the tractor unit and the first vehicle body, between the tractor unit and the second vehicle body, and between the first vehicle body and the second vehicle body to enable linkage between the two. Linkage joints that can be interconnected are provided at the front and rear ends of the first vehicle body and the front and rear ends of the second vehicle body. Support devices that keep the vehicle body in a stationary state are provided on the left and right sides of the first and second vehicle bodies.

[0006] By adopting the above technical solution, the lifting module formed by the truck-mounted crane and the vehicle body, and the transportation module formed by the flatbed truck, can greatly reduce the height requirements compared to a truck crane. Compared to a gantry crane, no on-site construction is required, which greatly improves the project progress. During construction, a single tractor unit can tow two lifting modules and one transportation module to the site. The transportation module is already carrying a steel box girder. After arriving at the site, the modules are separated, and the tractor unit adjusts the position and orientation of each module to obtain the optimal lifting position, thereby reducing the lifting difficulty and completing the lifting work quickly. The support device allows the first and second vehicle bodies to be stably maintained in the adjusted state and facilitates accurate docking by the linkage joint. In addition, the redesigned lifting module can further reduce the space occupied compared to the traditional truck-mounted crane, while reducing the driving difficulty caused by the excessive length of the vehicle body. Moreover, traditional truck-mounted cranes and flatbed trucks are equipped with a separate tractor unit. In this solution, a single tractor unit can adapt to each module to achieve towing and position adjustment, providing as much operating space as possible for the limited site space, and indirectly increasing the operating efficiency.

[0007] The present invention is further configured such that: the linkage joint includes a separate and opposing first bracket and a second bracket; the first bracket is located behind the tractor head, the first vehicle body, or the second vehicle body; the second bracket is located in front of the first vehicle body or the second vehicle body; the first bracket of the same linkage joint is located in front, and the second bracket is located in rear; a first column is provided above the rear end of the first bracket; a second column is provided above the front end of the second bracket; a waist-shaped linkage ring is sleeved between the first column and the second column; and threaded limiting screws are respectively provided above the linkage ring on the first column and the second column. The first support has a first left wing and a first right wing on its rear ends, and the second support has a second left wing and a second right wing on its front ends. A left guide post is provided behind the first left wing in the front-back direction, passing through the second left wing and movable back-and-forth relative to the second left wing. A left cylindrical spring is sleeved on the left guide post and compressed between the first left wing and the second left wing. A right guide post is provided in front of the second right wing in the front-back direction, passing through the first right wing and movable back-and-forth relative to the first right wing. A right cylindrical spring is sleeved on the right guide post and compressed between the first right wing and the second right wing.

[0008] By adopting the above technical solution, the tractor unit reverses or drives the first and second vehicle bodies to reverse, so that the first guide post passes through the second bracket and the second guide post passes through the first bracket. At the same time, the left and right cylindrical springs are compressed. After reversing to a certain extent, the linkage ring is fitted onto the first and second pillars. Disassembly can be performed by reversing the operation. In this docking structure, the linkage ring acts as the farthest distance limit, and the compressed spring acts as the shortest distance limit. The inner side of the linkage ring and the guide post cooperate to achieve front and rear guidance. Compared with the traditional mechanical connection where the pin passes through two brackets, it has a buffer space that can move back and forth. On the one hand, it avoids deformation of the traditional structure due to excessive force when the tractor unit decelerates, which would make it difficult to separate. This improves the convenience of repeated disassembly and assembly, allowing the vehicle body modules to be quickly assembled and pulled by a single tractor unit. It can also be quickly separated and deployed after arriving at the site. On the other hand, it reduces the deceleration or acceleration of the vehicle body when the tractor unit decelerates or accelerates, making the steel box girder transported by the vehicle body more stable and protecting the steel box girder.

[0009] The invention is further configured such that: the first left side wing faces the second left side wing and is provided with a first left alignment groove that matches the outer circumferential shape of the left cylindrical spring around the left guide post; the second left side wing is provided with a left guide hole for the left guide post to pass through; the second left side wing faces the first left side wing and is provided with a second left alignment groove that matches the outer circumferential shape of the left cylindrical spring around the left guide hole; the first right side wing is provided with a right guide hole for the right guide post to pass through; the first right side wing faces the second right side wing and is provided with a first right alignment groove that matches the outer circumferential shape of the right cylindrical spring around the right guide hole; the second right side wing faces the first right side wing and is provided with a second right alignment groove that matches the outer circumferential shape of the right cylindrical spring around the right guide post; and the openings of the first left alignment groove, the second left alignment groove, the first right alignment groove, and the second right alignment groove are all provided with guide chamfers.

[0010] By adopting the above technical solution, alignment grooves are set at both ends of each compression spring. The axial elastic force and radial elastic force of the cylindrical spring are used in a reasonable manner. When the tractor head is turning, the guide post will squeeze the guide hole wall. At this time, the radially deformed cylindrical spring will also offset part of the force, extending the service life of the guide post. At the same time, after the turn is completed, the radial elastic force will gradually align the guide hole and the guide post, ensuring the driving stability of the tractor head. The addition of a guide chamfer will automatically center the cylindrical spring during the assembly process, thereby realizing the rapid and accurate compression installation of the cylindrical spring.

[0011] The present invention is further configured such that: the first bracket is separately disposed from the tractor head, the first vehicle body, or the second vehicle body; the tractor head, the first vehicle body, or the second vehicle body is provided with a first mounting plate above and below the first bracket; the upper first mounting plate is provided with a first mounting groove in the left-right direction; the first bracket is provided with a first mounting protrusion in the left-right direction that matches the shape of the first mounting groove; at least two first mounting bolts passing through the first mounting protrusion pass through the first mounting plate and the first bracket; the second bracket is separately disposed from the first vehicle body or the second vehicle body; the first vehicle body or the second vehicle body is provided with a second mounting plate above and below the second bracket; the upper second mounting plate is provided with a second mounting groove in the left-right direction; the second bracket is provided with a second mounting protrusion in the left-right direction that matches the shape of the second mounting groove; at least two second mounting bolts passing through the second mounting protrusion pass through the second mounting plate and the second bracket.

[0012] By adopting the above technical solution, the split frame is easy to replace when the frame is damaged or when it is compatible with different vehicle bodies. The vehicle body is assembled by sliding into the mounting plate from one side. Due to the cooperation of the mounting protrusion and the mounting groove, the assembly area and assembly dimensions are increased, which improves the assembly stability. In addition, the mounting bolts pass through the mounting protrusion, which also makes the bolt hole length through the frame longer, further improving the assembly stability.

[0013] The invention is further configured such that: a transport flatbed is provided above the second vehicle body, the upper surface of the transport flatbed serves as the support surface of the steel box girder, and the support surface is provided with balance ports in sequence from front to back; a hydraulic lift is provided inside the second vehicle body corresponding to each balance port; a lifting platform is driven above the hydraulic lift, and the lifting platform passes through the balance port and abuts against the bottom of the steel box girder.

[0014] By adopting the above technical solution, the support surface still serves as the main support position. Multiple hydraulic lifts drive the corresponding lifting platforms to rise, thereby enabling different lifting platforms to adapt to the bottom of the steel box girder at different heights and achieve stable support at various points, reducing possible swaying during acceleration or deceleration, thus making the transmission of the steel box girder smoother.

[0015] The present invention is further configured such that: the lifting platform includes a base plate that cooperates with the hydraulic lift drive and a support plate that abuts against the bottom of the steel box girder; side plates are provided around the upper part of the base plate to form a lifting channel for the support plate to be lifted and lowered; a buffer space is formed between the base plate and the support plate; buffer columns arranged in a rectangle and fixed to the base plate are provided in the buffer space; and buffer springs compressed between the support plate and the base plate are sleeved on the buffer columns.

[0016] By adopting the above technical solution, in actual operation, there will inevitably be a gap between the lifting platform and the steel box girder. By adding a support plate and providing greater buffering force, the gap between the lifting platform and the steel box girder is compensated, while eliminating the impact force at the moment of contact, improving the support effect and extending the service life.

[0017] The present invention is further configured such that: the support plate is provided with a connecting rod and a storage channel for the connecting rod to move in the front-back direction along the front-back direction; the adjacent support plate is provided with a linkage slot for the connecting rod to be inserted to form linkage between adjacent substrates; the side plate is provided with a guide groove for the connecting rod to rise and fall; the end of the connecting rod is provided with a frustum-shaped guide block, and the smaller end of the frustum of the guide block faces the linkage slot.

[0018] By adopting the above technical solution, when the height of the steel box girder supported by adjacent support plates is the same, the connecting rod is inserted into the linkage slot of the adjacent support plate to form a support plate combination, thereby improving the support effect of the support plate. The storage channel is used to store the connecting rod when idle to avoid interfering with the lifting and lowering, while the guide groove allows some of the connecting rod to be exposed on the outside of the support plate, making it easy to insert and remove, improving the convenience of operation, and guiding the support plate at the same time, making the lifting and lowering of the support plate more stable.

[0019] The present invention is further configured such that: the support device includes a plurality of support arms located on the left and right sides of the first vehicle body or the second vehicle body respectively, one end of the support arm is hinged to the side of the first vehicle body or the second vehicle body and can swing horizontally, and the other end is provided with a hydraulic cylinder, which drives a support plate that is vertically lifted and supported on the ground.

[0020] By adopting the above technical solution, in order to keep the vehicle body stationary during the transfer, hoisting and module docking of the steel box girder, a support device is added to improve the stability of handling. The horizontally swinging support arm can fit against the side of the flatbed vehicle when idle, making the structure more compact. The hydraulically driven support device provides stable support and is implemented quickly. Attached Figure Description

[0021] Figure 1 This is a three-dimensional schematic diagram of a specific embodiment of the present invention;

[0022] Figure 2 This is a three-dimensional schematic diagram of the linkage connector;

[0023] Figure 3 This is a 3D view of the first support frame;

[0024] Figure 4 This is a 3D view of the second support.

[0025] Figure 5 This is a cross-sectional schematic diagram of the linkage joint;

[0026] Figure 6 This is a three-dimensional schematic diagram of the transportation module;

[0027] Figure 7 This is a cross-sectional view of the transportation module;

[0028] Figure 8 for Figure 7 Enlarged view of A in the middle;

[0029] Figure 9 This is a construction diagram. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0032] like Figure 1 — Figure 9 As shown, this invention discloses a modular steel box girder hoisting system specifically designed for confined spaces, including a tractor unit 1, two hoisting modules, and a transport module. The hoisting module includes a first vehicle body 2 and a truck-mounted crane 3 installed on the first vehicle body 2. The transport module includes a second vehicle body 4, which is a flatbed truck with a support surface on top to support the steel box girder. Linkage joints that enable linkage between the tractor unit 1 and the first vehicle body 2, between the tractor unit and the second vehicle body 4, and between the first vehicle body 2 and the second vehicle body 4 are provided. Linkage joints that can be interconnected are provided at the front and rear ends of the first vehicle body 2 and the front and rear ends of the second vehicle body 4, respectively. Support devices that keep the vehicle body in a stationary state are provided on the left and right sides of the first vehicle body 2 and the second vehicle body 4, respectively.

[0033] The linkage joint includes a separate and opposing first bracket 5 and a second bracket 6. The first bracket 5 is located behind the tractor head 1, the first vehicle body 2, or the second vehicle body 4, and the second bracket 6 is located in front of the first vehicle body 2 or the second vehicle body 4. In the same linkage joint, the first bracket 5 is located in front, and the second bracket 6 is located behind. A first column 51 is located above the rear end of the first bracket 5, and a second column 61 is located above the front end of the second bracket 6. A waist-shaped linkage ring 7 is fitted between the first column 51 and the second column 61. Threaded limiting nuts 71 are respectively located above the linkage ring 7 on the first column 51 and the second column 61. A second column 71 is located on each side of the rear end of the first bracket 5. A left wing 52 and a first right wing 53 are provided on the front sides of the second bracket 6, and a second left wing 62 and a second right wing 63 are respectively provided on both sides of the front end. A left guide post 521 is provided behind the first left wing 52 along the front-back direction, passing through the second left wing 62 and being movable back-and-forth relative to the second left wing 62. A left cylindrical spring 522 is sleeved on the left guide post 521 and compressed between the first left wing 52 and the second left wing 62. A right guide post 631 is provided in front of the second right wing 63 along the front-back direction, passing through the first right wing 53 and being movable back-and-forth relative to the first right wing 53. A right cylindrical spring 632 is sleeved on the right guide post 631 and compressed between the first right wing 53 and the second right wing 63.

[0034] The first left wing 52 faces the second left wing 62 and is provided with a first left alignment groove 523 that matches the outer circumference of the left cylindrical spring 522 around the left guide post 521. The second left wing 62 is provided with a left guide hole 621 through which the left guide post 521 passes. The second left wing 62 faces the first left wing 52 and is provided with a second left alignment groove 622 that matches the outer circumference of the left cylindrical spring 522 around the left guide hole 621. The first right wing 53 is provided with a right guide hole 531 through which the right guide post 631 passes. The first right wing 53 faces the second right wing 63 and is provided with a first right alignment groove 532 that matches the outer circumferential shape of the right cylindrical spring 632 around the right guide hole 531. The second right wing 63 faces the first right wing 53 and is provided with a second right alignment groove 633 that matches the outer circumferential shape of the right cylindrical spring 632 around the right guide post 631. The openings of the first left alignment groove 523, the second left alignment groove 622, the first right alignment groove 532 and the second right alignment groove 633 are all provided with a guide chamfer a.

[0035] The first bracket 5 is separately disposed from the tractor body 1, the first vehicle body 2, or the second vehicle body 4. The tractor body 1, the first vehicle body 2, or the second vehicle body 4 is provided with a first mounting plate 21 above and below the first bracket 5. The first mounting plate 21 located above the first bracket 5 is provided with a first mounting groove 22 in the left-right direction. The first bracket 5 is provided with a first mounting protrusion 54 in the left-right direction that matches the shape of the first mounting groove 22. At least two first mounting bolts 23 passing through the first mounting protrusion 54 pass through the first mounting plate 21 and the first bracket 5. The second bracket 6 is separately disposed from the first vehicle body 2 or the second vehicle body 4. The first vehicle body 2 or the second vehicle body 4 is provided with a second mounting plate 41 above and below the second bracket 6. The second mounting plate 41 located above the second bracket 6 is provided with a second mounting groove 42 in the left-right direction. The second bracket 6 is provided with a second mounting protrusion 64 in the left-right direction that matches the shape of the second mounting groove 42. At least two second mounting bolts 43 passing through the second mounting protrusion 64 pass through the second mounting plate 42 and the second bracket 6. All of the above bolts are locked with nuts.

[0036] A transport flatbed 8 is installed above the second vehicle body 4. The upper surface of the transport flatbed 8 serves as the support surface 81 of the steel box girder. Balance ports 82 are arranged sequentially along the support surface 81 from front to back. A hydraulic lift 9 is installed inside the second vehicle body 4 corresponding to each balance port 82. The hydraulic lift 9 is a drive device with an X-shaped structure that is electrically controlled and driven by hydraulic cylinders. It is a commercially available component, and its drive principle is not described, but it does not affect the understanding of the structure. A lifting platform 91 is driven above the hydraulic lift 9. The lifting platform 91 passes through the balance port 82 and rests against the bottom of the steel box girder.

[0037] The lifting platform 91 includes a base plate 911 that is driven and cooperates with the hydraulic lift 9 and a support plate 912 that abuts against the bottom of the steel box girder. Side plates 913 are provided around the upper part of the base plate 911 to form a lifting channel for the support plate 912 to be raised and lowered. A buffer space 914 is formed between the base plate 911 and the support plate 912. Buffer columns 9111 arranged in a rectangle and fixed to the base plate 911 are provided in the buffer space 914. Buffer springs 9112 compressed between the support plate 912 and the base plate 911 are sleeved on the buffer columns 9111.

[0038] The support plate 912 is provided with a connecting rod 9121 and a storage channel 9122 for the connecting rod 9121 to move in the front-back direction. The adjacent support plate 912 is provided with a linkage slot 9123 for the connecting rod 9121 to be inserted to form a linkage between adjacent substrates 911. The side plate 913 is provided with a guide groove 9131 for the connecting rod 9121 to rise and fall. The end of the connecting rod 9121 is provided with a frustum-shaped guide block 9124, with the smaller end of the frustum of the guide block 9124 facing the linkage slot 9123.

[0039] The support device includes multiple support arms 24 located on the left and right sides of the first vehicle body 2 or the second vehicle body 4 respectively. One end of the support arm 24 is hinged to the side of the first vehicle body 2 or the second vehicle body 4 and can swing horizontally. The other end is provided with a hydraulic cylinder 241. The hydraulic cylinder 241 drives a support plate 242 that is vertically lifted and supported on the ground.

[0040] by Figure 7 , Figure 8 Taking the steel box girder b as an example, the principle of this device is explained. Observing the bottom shape of the steel box girder b, there is a height difference between the left side of the steel box girder b and the support surface 81, and they are at the same height. Pull out the connecting rod 9121 of the left first support plate 912 and insert it into the linkage slot 9123 of the left second support plate 912, so that the left first support plate 912 and the left second support plate 912 form a support unit, increasing the support area and support effect. Then, the two lifting platforms 91 on the left are raised until the left first support plate 312 and the left second support plate 912 are attached to the bottom of the steel box girder b, while the right first lifting platform 91 and the right second lifting platform 91 remain stationary, relying on the support surface 12 for support.

[0041] by Figure 9 Taking this as an example, the rapid working sequence after the system arrives at the site is explained as follows: ① The tractor unit 1 pulls the first vehicle body 2-second vehicle body 4-first vehicle body 2 in sequence to a position parallel to the required lifting position (dashed line position); ② The first vehicle body 2 at the front end is separated from the second vehicle body 4, and the tractor unit 1 adjusts the separated first vehicle body 2 to a fixed position perpendicular to the required lifting position; ③ The truck-mounted cranes 3 of the two first vehicle bodies 2 are fixed to the front and rear of the steel beam box respectively; ④ The two truck-mounted cranes 3 work together to quickly transport the steel beam box to the required lifting position; ⑤ During the lifting process, the second vehicle body 4 is separated from the first vehicle body 2 at the rear end, and the tractor unit 1 pulls the separated second vehicle body 4 to the position of the supplementary steel beam box; ⑥ ​​The second vehicle body 4 returns to the initial position, and the lifting steps are repeated to quickly complete the lifting process; ⑦ The two first vehicle bodies 2 and one second vehicle body 4 are reconnected, and the tractor unit 1 can then pull the vehicle away from the site.

Claims

1. A modular steel box girder hoisting system specifically designed for confined spaces, comprising a tractor unit, characterized in that: It also includes two hoisting modules and one transportation module. The hoisting module includes a first vehicle body and a truck-mounted crane installed on the first vehicle body. The transportation module includes a second vehicle body, which is a flatbed truck. The flatbed truck has a support surface on top to support the steel box girder. Linkage joints are provided between the tractor and the first vehicle body, between the tractor and the second vehicle body, and between the first and second vehicle bodies to enable their linkage. Linkage joints that can be interconnected are provided at the front and rear ends of the first and second vehicle bodies, respectively. Support devices are provided on the left and right sides of the first and second vehicle bodies to keep the vehicles stationary. A transportation flatbed is provided on top of the second vehicle body. The upper surface of the transportation flatbed serves as the support surface for the steel box girder. Balance ports are sequentially arranged on the support surface from front to back. Hydraulic lifts are installed inside the second vehicle body corresponding to each balance port. The hydraulic lift described above is equipped with a lifting platform. The lifting platform passes through the balance port and abuts against the bottom of the steel box girder. The lifting platform includes a base plate that cooperates with the hydraulic lift drive and a support plate that abuts against the bottom of the steel box girder. Side plates are provided around the base plate to form a lifting channel for the support plate to move up and down. A buffer space is formed between the base plate and the support plate. Buffer columns arranged in a rectangle and fixed to the base plate are provided in the buffer space. Buffer springs compressed between the support plate and the base plate are sleeved on the buffer columns. The support plate is provided with a connecting rod and a storage channel for the connecting rod to move in the front-back direction. The adjacent support plate is provided with a linkage slot for the connecting rod to be inserted to form a linkage between adjacent base plates. The side plates are provided with guide grooves for the connecting rod to move up and down. A frustum-shaped guide block is provided at the end of the connecting rod, with the smaller end of the frustum of the guide block facing the linkage slot.

2. The modular steel box girder hoisting system for confined spaces according to claim 1, characterized in that: The linkage joint includes a split and opposing first bracket and a second bracket. The first bracket is located behind the tractor head, first vehicle body, or second vehicle body, and the second bracket is located in front of the first vehicle body or second vehicle body. The first bracket is located in front, and the second bracket is located in rear. A first column is located above the rear end of the first bracket, and a second column is located above the front end of the second bracket. A waist-shaped linkage ring is fitted between the first and second columns. Threaded limiting nuts are respectively installed above the linkage ring on the first and second columns. The first support has a first left wing and a first right wing on its rear sides, and the second support has a second left wing and a second right wing on its front sides, respectively. A left guide post is provided behind the first left wing along the front-back direction, passing through the second left wing and movable back-and-forth relative to the second left wing. A left cylindrical spring is sleeved on the left guide post and compressed between the first left wing and the second left wing. A right guide post is provided in front of the second right wing along the front-back direction, passing through the first right wing and movable back-and-forth relative to the first right wing. A right cylindrical spring is sleeved on the right guide post and compressed between the first right wing and the second right wing.

3. The modular steel box girder hoisting system for confined spaces according to claim 2, characterized in that: The first left wing faces the second left wing and is provided with a first left alignment groove that matches the outer circumference of the left cylindrical spring around the left guide post. The second left wing is provided with a left guide hole for the left guide post to pass through. The second left wing faces the first left wing and is provided with a second left alignment groove that matches the outer circumference of the left cylindrical spring around the left guide hole. The first right wing is provided with a right guide hole for the right guide post to pass through. The first right wing faces the second right wing and is provided with a first right alignment groove that matches the outer circumference of the right cylindrical spring around the right guide hole. The second right wing faces the first right wing and is provided with a second right alignment groove that matches the outer circumference of the right cylindrical spring around the right guide post. The openings of the first left alignment groove, the second left alignment groove, the first right alignment groove, and the second right alignment groove are all provided with guide chamfers.

4. The modular steel box girder hoisting system for confined spaces according to claim 2, characterized in that: The first bracket is separately disposed from the tractor head, the first vehicle body, or the second vehicle body. The tractor head, the first vehicle body, or the second vehicle body is provided with a first mounting plate above and below the first bracket. The upper first mounting plate is provided with a first mounting groove in the left-right direction. The first bracket is provided with a first mounting protrusion in the left-right direction that matches the shape of the first mounting groove. At least two first mounting bolts passing through the first mounting protrusion pass through the first mounting plate and the first bracket. The second bracket is separately disposed from the first vehicle body. The first vehicle body or the second vehicle body is provided with a second mounting plate above and below the second bracket. The upper second mounting plate is provided with a second mounting groove in the left-right direction. The second bracket is provided with a second mounting protrusion in the left-right direction that matches the shape of the second mounting groove. At least two second mounting bolts passing through the second mounting protrusion pass through the second mounting plate and the second bracket.

5. The modular steel box girder hoisting system for confined spaces according to claim 1, characterized in that: The support device includes multiple support arms located on the left and right sides of the first or second vehicle body respectively. One end of each support arm is hinged to the side of the first or second vehicle body and can swing horizontally, while the other end is equipped with a hydraulic cylinder. The hydraulic cylinder drives a support plate that is vertically raised and lowered and supported on the ground.

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