Iron-spanning large-tonnage steel box girder falling device and using method thereof

Abstract

The invention relates to the technical field of steel box girder transportation devices, in particular to an iron-spanning large-tonnage steel box girder falling device and a using method thereof.The iron-spanning large-tonnage steel box girder falling device comprises a rack, a sliding rail is fixedly installed on the inner side of the rack, the sliding rail is arranged in the length direction of the rack and used for providing a guiding and bearing foundation for all moving parts, and two lifting cylinders are symmetrically arranged in the rack; a lifting column is vertically and slidably arranged at the upper end of each lifting cylinder in a penetrating mode, two sets of buffering assemblies are symmetrically arranged in the center beam, each buffering assembly comprises a buffering plug, and the buffering plugs are slidably installed in buffering pipes. Inertial kinetic energy of a beam body is absorbed by utilizing a transient pressure difference gradient between the first pressure cavity and the second buffer cavity, so that an impact load at the instant of sudden stop is effectively buffered, beam body jumping caused by compressibility of hydraulic oil is prevented, the risk of hard landing in the super-tonnage beam falling process is solved, and extremely high safety redundancy is provided.

Description

Technical Field

[0001] This invention relates to the technical field of steel box girder transportation devices, specifically to a device for lowering large-tonnage steel box girders across railways and its usage method. Background Technology

[0002] Steel box girders are widely used in railway bridge projects due to their advantages such as strong integrity, high load-bearing capacity and suitability for large-span structures. In the construction scenario of railway crossing (railway crossing: bridge projects that cross railways and highways), the lowering operation of large-tonnage steel box girders is limited by the safety of existing line operation and the construction time window ("maintenance window"). It not only requires high precision, but also good stability and safety redundancy.

[0003] To address the inertia problem during the lowering of large-tonnage steel box girders, existing technologies mostly employ rigid supports or simple throttling methods for control, lacking effective non-rigid buffer structures. When the lifting device stops or a sudden pressure change occurs, the kinetic energy of the falling girder is difficult to absorb in time, easily leading to a "hard landing" phenomenon. This not only results in a large structural impact but may also cause the girder to rebound or vibrate, increasing construction risks. At the same time, existing buffering methods usually have limited adjustment capabilities, making it difficult to achieve dynamic matching of flow and pressure according to different working conditions, resulting in unstable buffering effects. Therefore, this application proposes a girder lowering device for large-tonnage steel box girders spanning railways and its usage method. Summary of the Invention

[0004] The purpose of this invention is to provide a device for lowering large-tonnage steel box girders across railways and its method of use, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a device for lowering a large-tonnage steel box girder across a railway, comprising a frame, wherein a slide rail is fixedly installed on the inner side of the frame, the slide rail being arranged along the length of the frame to provide guidance and bearing foundation for each moving component; two lifting cylinders are symmetrically arranged inside the frame, the two lifting cylinders being fixedly connected by a central beam to form an integral force-bearing structure and ensure synchronicity and stability during the lifting process; a lifting column is vertically slidably inserted through the upper end of each lifting cylinder, the upper end of the lifting column being used to support the bottom of the steel box girder; when the pressure inside the lifting cylinder increases, the lifting column moves upward with the increase in pressure, thereby smoothly lifting the steel box girder; two sets of buffer components are symmetrically arranged inside the central beam, the buffer components including buffer plugs, the buffer plugs being slidably installed inside buffer tubes, the buffer plugs dividing the inner cavity of the buffer tube into a first pressure chamber and a second buffer chamber.

[0006] As a further embodiment of the present invention, the bottom end of the lifting cylinder is slidably connected to the upper surface of the slide rail, so that the lifting cylinder and its upper structure can be adjusted in position along the slide rail, thereby realizing the lateral fine adjustment and alignment of the steel box girder during the beam lowering process. A support plate is slidably installed on the surface of the slide rail, and a push column is fixedly installed on the upper end of the support plate. The push column is arranged along the extension direction of the slide rail.

[0007] As a further embodiment of the present invention, a limiting box is fixedly installed on the upper end of the support plate, and a locking block is provided at the inner end of the limiting box. The bottom end of the locking block abuts against the crossbeam on the surface of the slide rail.

[0008] As a further embodiment of the present invention, a control cylinder is fixedly installed at one end of each of the two buffer tubes that are close to each other. The buffer tubes are fixedly connected to the lifting cylinder. A passive ring is movably installed inside the control cylinder. A central rod is fixedly installed on the surface of the passive ring. The central rod extends axially and passes through the interior of the corresponding buffer tube. A seepage plate is slidably installed at the inner end of the buffer plug, and the seepage plate is fixedly connected to the central rod, so that the movement of the buffer plug can be synchronously transmitted to the passive ring through the central rod.

[0009] As a further embodiment of the present invention, a passive disk is provided between the seepage disk and the central rod. The passive disk is coaxially arranged with the central rod. The surface of the seepage disk is provided with a plurality of guide holes and seepage holes in a ring shape. A plurality of sealing plugs are fixedly installed at the end of the passive disk away from the central rod. The plurality of sealing plugs are arranged one-to-one with the corresponding guide holes for selectively blocking or opening the guide holes.

[0010] As a further embodiment of the present invention, multiple flow-limiting columns are provided through the surface of the passive disk, and the flow-limiting columns are respectively inserted into the corresponding seepage holes. Multiple sliding plates are slidably installed on the outer surface of the central rod. The multiple sliding plates are evenly distributed in a ring and are fixedly connected to the passive disk. By setting multiple flow-limiting columns on the surface of the passive disk and inserting them into the seepage holes, and combining the sliding plates on the outer surface of the central rod with the fixed connection to the passive disk, the buffer assembly can form a controllable flow resistance when the hydraulic medium flows, thereby achieving precise adjustment of the liquid flow rate.

[0011] As a further embodiment of the present invention, a driving ring and a passive sleeve are coaxially rotatably installed inside the control cylinder. The passive sleeve and the driving ring are on the same axis and are fixedly connected to multiple sliding plates. A transmission rod is provided through the interior of the central rod. A limiting arc ring is rotatably installed at one end of the central rod near the seepage plate. A rectangular hole is provided on the outer surface of the central rod.

[0012] As a further embodiment of the present invention, the surface of the limiting arc ring is provided with multiple inclined notches in the circumferential direction, and the inclined surface of each inclined notch contacts the end of the corresponding flow-limiting column. The end of the flow-limiting column near the limiting arc ring is provided with an inclined surface structure that matches the inclined notch, so as to enhance the contact fit and improve the transmission stability. The outer surface of the buffer plug is fitted with a sealing ring, and a support spring is provided between the sealing ring and the buffer plug. The surface of the buffer plug is provided with multiple through-block mounting positions, and each through-block is provided with a guide groove. The side of the seepage plate near the central rod is provided with a driving ring.

[0013] As a further embodiment of the present invention, the conical surface of the drive ring contacts the through-block, pushing the through-block to move away from the buffer plug. The guide groove on the through-block connects the inner space of the sealing ring with the inner space of the buffer plug. The through-block is pushed to move axially by the action of the conical surface of the drive ring, so that the guide groove on the through-block connects the inner space of the sealing ring with the inner space of the buffer plug, realizing the controlled flow of hydraulic medium in the buffer cavity, thereby ensuring the smooth flow of buffer solution during the lowering of the steel box girder.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, by setting a linkage structure of a central beam, lifting cylinder and lifting column on the frame, and supplementing it with a "pressure self-sealing" adaptive sealing system composed of sealing rings, support springs and through-blocks, enables multiple lifting support points to form a coupled whole at the level of physical structure and hydraulic circuit. This effectively solves the problem of asynchronous lifting caused by response delay or flow fluctuation in multi-point independent hydraulic control in the prior art, ensuring that the force on each support point of the large-tonnage steel box girder is uniform during the beam lowering process, and significantly improving the overall structural stability and construction safety under heavy load conditions. 2. This invention constructs a non-rigid buffer system through a buffer tube, a buffer plug, and a seepage plate with seepage holes. It utilizes the transient pressure gradient between the first pressure chamber and the second buffer chamber to absorb the inertial kinetic energy of the beam. Combined with the graded flow regulation structure formed by the guide hole, sealing plug, flow limiting column, and limiting arc ring, it realizes the dynamic switching of the hydraulic medium from "rapid flow" to "restricted seepage". This effectively buffers the impact load of sudden stop, prevents the beam from jumping due to the compressibility of hydraulic oil, solves the risk of "hard landing" during the process of lowering ultra-large tonnage beams, and provides extremely high safety redundancy. 3. This invention utilizes a cyclic propulsion mechanism consisting of a propulsion cylinder, a locking block, and a triangular plate, combined with a lateral limiting structure of a slide rail and a support plate, to achieve an automated cyclic operation of "propulsion-locking-unlocking-returning". Furthermore, it employs the mechanical linkage between the passive rod and the triangular plate to achieve automatic switching of the limiting state. This not only solves the technical pain points of traditional mobile equipment being prone to slippage and having poor positioning accuracy in restricted working conditions such as railway crossings, but also effectively disperses the track compressive stress through surface contact support, enhancing the device's adaptability to complex construction environments. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the steel box girder lowering device; Figure 2 This is a schematic diagram of the disassembled structure of the lifting cylinder and slide rails. Figure 3 This is a structural schematic diagram of the propulsion tube cross-section; Figure 4 This is a schematic diagram of the internal structure of the central beam; Figure 5 This is a schematic diagram of the internal structure of the buffer tube; Figure 6 This is an enlarged structural diagram of the inside of the buffer tube; Figure 7 This is a schematic diagram of the decomposed structure of the sliding plate and the passive ring; Figure 8 This is a schematic diagram of the internal structure of the buffer plug; Figure 9 This is a schematic diagram of the disassembled structure of the seepage plate and the central rod. Figure 10 This is a schematic diagram of the cross-section of the seepage plate; Figure 11 This is a schematic diagram of the structure of the seepage hole and the flow-limiting column; Figure 12 This is a schematic diagram of the structure at the buffer plug.

[0016] In the diagram: 1. Frame; 2. Slide rail; 101. Propulsion cylinder; 102. Support plate; 103. Lifting cylinder; 104. Center beam; 105. Lifting column; 106. Propulsion column; 107. Limiting box; 108. Locking block; 109. Passive push rod; 110. Triangular plate; 111. Passive rod; 201. Buffer tube; 202. Hydraulic tube; 203. Control cylinder; 204. Angle adjustment motor; 205. Passive ring; 206. Buffer plug; 207. Center rod; 208. Sliding plate; 209. Electric actuator; 210. Drive ring; 211. Passive sleeve; 212. Force-bearing block; 213. Transmission rod; 301. Sealing ring; 302. Support spring; 303. Through block; 304. Conductor groove; 401. Leakage plate; 402. Flow guide hole; 403. Leakage hole; 404. Flow limiting column; 405. Sealing plug; 406. Passive plate; 407. Limiting arc ring; 408. Drive ring. Detailed Implementation

[0017] The technical solutions of 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 scope of protection of the present invention.

[0018] Example 1: Please refer to Figures 1-3 A device for lowering a large-tonnage steel box girder across a railway and its method of use are disclosed. The device includes a frame 1, with a slide rail 2 fixedly installed on the inner side of the frame 1 by bolts. The slide rail 2 is arranged along the length of the frame 1 and is used to provide guidance and bearing foundation for each moving part. Two lifting cylinders 103 are symmetrically arranged inside the frame 1. The two lifting cylinders 103 are fixedly connected by a central beam 104 to form an overall load-bearing structure and ensure synchronicity and stability during the lifting process. A lifting column 105 is vertically slidably inserted through the upper end of each lifting cylinder 103. The upper end of the lifting column 105 is used to support the bottom of the steel box girder. When the internal pressure of the lifting cylinder 103 increases, the lifting column 105 moves upward with the increase of pressure, thereby smoothly lifting the steel box girder. When the internal pressure of the lifting cylinder 103 gradually decreases, the lifting column 105 slowly falls back under the weight of the steel box girder, realizing the controllable lowering of the steel box girder, so as to meet the requirements of stability and synchronization during the lowering of large-tonnage steel box girders. The bottom end of the lifting cylinder 103 is slidably connected to the upper surface of the slide rail 2, so that the lifting cylinder 103 and its upper structure can be adjusted along the slide rail 2, thereby realizing the lateral fine adjustment and alignment of the steel box girder during the beam lowering process. The surface contact support method of the slide rail 2 replaces the wheel support, effectively dispersing the contact stress and avoiding local damage to the slide rail 2 due to excessive concentrated load, thus improving the overall load-bearing reliability. A support plate 102 is slidably installed on the surface of the slide rail 2, and a push column 106 is fixedly installed on the upper end of the support plate 102. The push column 106 is set along the extension direction of the slide rail 2, and the push column 106 is detachably connected to the center beam 104 through a pin, so as to facilitate quick assembly and disassembly under different working conditions and realize the linkage or separation control of the push and lifting structure. Specifically, a limit box 107 is fixedly installed on the upper end of the support plate 102. A locking block 108 is provided at the inner end of the limit box 107. The locking block 108 and the limit box 107 are connected by a spring sheet (not shown in the figure). Under the action of the spring sheet, the locking block 108 always maintains a downward movement trend. The bottom end of the locking block 108 abuts against the crossbeam on the surface of the slide rail 2. Thus, during the process of the push column 106 driving the center beam 104 to move, the support plate 102 is provided with intermittent limit support, which avoids slippage or instability under heavy load and improves the safety and reliability of the push process. The limiting box 107 is also equipped with a triangular plate 110, which passes through the locking block 108 and forms a mating structure with it. When the triangular plate 110 is inserted into the locking block 108, under the action of its inclined guide surface, it can drive the locking block 108 to overcome the elastic force and move upward, so that the locking block 108 is disengaged from the lateral limiting structure of the slide rail 2, thereby releasing the limitation on the support plate 102 and realizing the continued advancement of the device. A passive rod 111 is installed through the inside of the push cylinder 101. The passive rod 111 is fixedly connected to the push column 106 and moves synchronously with the push column 106. The passive rod 111 moves away from the push column 106. One end of the 6 is fixedly connected to a passive push rod 109, which is fixedly connected to a triangular plate 110. Thus, during the forward movement of the push column 106, the passive push rod 111 drives the triangular plate 110 to move synchronously, achieving automatic unlocking and reset control of the locking block 108. Two sets of buffer assemblies are symmetrically arranged inside the central beam 104. Each buffer assembly includes a buffer plug 206, which is slidably installed inside the buffer tube 201. The buffer plug 206 divides the inner cavity of the buffer tube 201 into a first pressure chamber and a second buffer chamber. The buffer chamber is located on the left side of the buffer plug 206, and the pressure chamber is located on the right side of the buffer plug 206. Figure 5 (As shown).

[0019] Example 2: Please refer to Figures 5-7 A method for lowering a large-tonnage steel box girder across a railway and its application, based on Embodiment 1, involves fixing control cylinders 203 at the close ends of two buffer pipes 201. The buffer pipes 201 are fixedly connected to the lifting cylinder 103. The input ends of the two buffer pipes 201 are connected in parallel to the working chambers of the corresponding lifting cylinders 103 via hydraulic pipes 202, and pressure is synchronously pumped by a hydraulic device. Through this parallel circuit, the internal pressure of the buffer pipes 201 can sense the load fluctuations and movement of the lifting column 105 in real time, thereby ensuring that the buffer plug 206 generates instantaneous compensation displacement when the pressure changes abruptly, and is then controlled by hydraulic... The pressure device directly pumps pressure (the hydraulic device here is an existing mature technology, which will not be described in detail here). The buffer plug 206 moves according to the pressure change inside the buffer pipe 201. When there is a sudden pressure change or the lifting column 105 has a rapid downward trend, the buffer plug 206 is displaced under the action of the pressure difference between the two chambers. Through the flow lag of the liquid medium and the pressure transient imbalance, the impact energy is absorbed and released, thereby effectively preventing the lifting column 105 from stopping suddenly or falling with impact, avoiding excessive impact load on the large tonnage steel box girder due to inertia during the beam lowering process, and improving the safety and stability of the overall structure. A passive ring 205 is movably installed inside the control cylinder 203, and a pressure balance hole (or oil compensation channel) communicating with the outside is opened on the wall of the control cylinder 203 to eliminate the air cushion resistance or vacuum suction force generated by the passive ring 205 during axial movement, so as to ensure the response sensitivity of the passive ring 205 when it moves with the center rod 207. The center rod 207 is fixedly installed on the surface of the passive ring 205. The center rod 207 extends axially and passes through the corresponding buffer tube 201. A seepage plate 401 is slidably installed on the inner end of the buffer plug 206, and the seepage plate 401 is fixedly connected to the center rod 207 so that the movement of the buffer plug 206 can be synchronously transmitted to the passive ring 205 through the center rod 207. Two limit rings are fixedly installed on the inner end of the buffer plug 206 to limit the movement position of the seepage plate 401.

[0020] like Figures 6-9 As shown, a passive disk 406 is provided between the seepage disk 401 and the central rod 207. The passive disk 406 is coaxially arranged with the central rod 207. The surface of the seepage disk 401 is provided with multiple guide holes 402 and seepage holes 403 arranged in a ring. The guide holes 402 are used to realize the rapid conduction of liquid, and the seepage holes 403 are used to realize restricted seepage. Multiple sealing plugs 405 are fixedly installed at the end of the passive disk 406 away from the central rod 207. The multiple sealing plugs 405 are arranged one-to-one with the corresponding guide holes 402, and are used to selectively block or open the guide holes 402. At the same time, multiple flow-limiting columns 404 are provided through the surface of the passive disk 406. The flow-limiting columns 404 are respectively inserted into the corresponding seepage holes 403, thereby limiting the effective flow section of the seepage holes 403, so as to regulate the liquid flow rate and enhance the buffer stability. Furthermore, multiple sliding plates 208 are slidably mounted on the outer surface of the central rod 207. The multiple sliding plates 208 are evenly distributed in a ring and are fixedly connected to the driven disk 406, so that the driven disk 406 can slide along the axial direction of the central rod 207. The drive ring 210 and the driven sleeve 211 are coaxially rotatably mounted inside the control cylinder 203. The driven sleeve 211 and the drive ring 210 are on the same axis and are fixedly connected to the multiple sliding plates 208, thus forming a transmission structure that converts rotational motion into axial displacement. The outer surface of the driving ring 210 is provided with an inclined plate, and the outer surface of the passive sleeve 211 is fixedly equipped with multiple force blocks 212 in a ring shape. The multiple force blocks 212 are in contact with the inclined plate. When the driving ring 210 rotates, under the guidance of the inclined plate, the force blocks 212 generate relative displacement along the inclined surface, thereby driving the passive sleeve 211 to move axially, and driving the passive disk 406 and the flow-limiting column 404 to move synchronously along the direction of the central rod 207 through the sliding plate 208. An electric actuator 209 is fixedly installed on the inner end of the control cylinder 203. The output end of the electric actuator 209 is movably connected to the off-center part of the drive ring 210. When the extension end of the electric actuator 209 is extended, it drives the drive ring 210 to rotate.

[0021] like Figure 6 , Figure 7 , Figures 9-11 As shown, a transmission rod 213 is installed through the interior of the central rod 207. A limiting arc ring 407 is rotatably installed at one end of the central rod 207 near the seepage plate 401. A rectangular hole is opened on the outer surface of the central rod 207. The limiting arc ring 407 and the transmission rod 213 are connected by an auxiliary rod (not shown in the figure) to realize the drive control of the limiting arc ring 407 by the transmission rod 213. The surface of the limiting arc ring 407 is provided with multiple inclined notches in the circumferential direction. The inclined surface of each inclined notch is in contact with the end of the corresponding flow limiting post 404. Correspondingly, the end of the flow limiting post 404 near the limiting arc ring 407 is provided with an inclined surface structure that matches the inclined notch, so as to enhance the contact fit and improve the transmission stability. When the sealing plug 405 closes the guide hole 402, the liquid in the buffer tube 201 mainly flows through the seepage hole 403 in a restricted manner. At this time, the pressure formed on one side of the seepage plate 401 pushes the flow-limiting column 404 to move axially. During this process, the limiting arc ring 407 rotates slowly under the action of pressure and structural cooperation. The rise angle of the inclined notch on the limiting arc ring 407 is designed to be a non-self-locking structure that is greater than the material friction angle. With the high reduction ratio output torque of the angle adjustment motor 204, it is ensured that even when there is a huge pressure difference on both sides of the seepage plate 401, the end side pressure of the flow-limiting column 404 can still be overcome, so as to realize the dynamic graded adjustment of the fluid channel cross section, thereby realizing the gradual adjustment of the fluid channel, achieving the purpose of flow restriction, and avoiding the impact damage to the device structure caused by the instantaneous transmission of pressure too fast.

[0022] Specifically, an angle adjustment motor 204 is fixedly installed on the outer surface of the control cylinder 203. The output end of the angle adjustment motor 204 is fixedly connected to the transmission rod 213 and is used to actively adjust the rotation angle of the limiting arc ring 407, thereby realizing the controllable adjustment of the motion state and buffering characteristics of the flow limiting column 404 to adapt to the buffering requirements under different beam dropping conditions.

[0023] like Figure 8 , Figure 12As shown, a sealing ring 301 is fitted on the outer surface of the buffer plug 206. The sealing ring 301 is preferably made of polyurethane (PU) or polytetrafluoroethylene to improve wear resistance and sealing performance. A support spring 302 is provided between the sealing ring 301 and the buffer plug 206. The support spring 302 has a "V" shaped structure and is used to provide radial support force. Multiple through-block 303 mounting positions are opened on the surface of the buffer plug 206. Each through-block 303 is provided with a guide groove 304. A drive ring 408 is provided on the side of the seepage plate 401 near the central rod 207. The drive ring 408 has a tapered structure on the side near the switch block 303. When the buffer plug 206 tends to displace under pressure fluctuations, the passive ring 205 is constrained by the stroke limit at the end of the control cylinder 203, causing a relative axial displacement between the drive ring 408 fixed on the central rod 207 and the buffer plug 206. Under this relative displacement, the tapered surface of the drive ring 408 forcefully compresses the switch block 303 to expand away from the axis, thereby triggering the radial reinforcement support of the sealing ring 301. The tapered surface of the drive ring 408 contacts the switch block 303, pushing the switch block 303 away from the buffer plug 206. The moving block 303 connects the inner space of the sealing ring 301 with the inner space of the buffer plug 206 through the through groove 304, realizing local pressure transmission. At the same time, the moving block 303 compresses the support spring 302 and causes elastic deformation, causing the side of the support spring 302 away from the buffer plug 206 to open to both sides and apply radial support force to the sealing ring 301. This makes the sealing ring 301 fit more tightly with the inner wall of the buffer tube 201 under pressure, forming a "pressure self-sealing" structure. That is, the higher the pressure, the stronger the sealing effect. By default, the flow-limiting column 404 is always inserted inside the leakage hole 403.

[0024] The working principle of this invention is: In use, the frame 1 is moved to the predetermined position under the steel box girder, and the overall alignment is completed by the slide rail 2. Then, the lifting cylinder 103 is controlled to work, so that the lifting column 105 extends upward and abuts against the bottom of the steel box girder to support the steel box girder. On this basis, by adjusting the internal pressure of the lifting cylinder 103, the lifting column 105 is slowly lowered, thereby driving the steel box girder to be lowered smoothly. During the lowering of the steel box girder, the electric actuator 209 drives the ring 210 to rotate. Under the action of its inclined structure, the passive sleeve 211 and the sliding plate 208 move axially along the central rod 207, thereby causing the passive disc 406 to be displaced. At this time, the sealing plug 405 disengages from the guide hole 402, the guide channel is opened, and the hydraulic medium can flow rapidly in the buffer pipe 201 to meet the flow requirements when the steel box girder is continuously lowered, thereby improving the stability of the lowering process. When the steel box girder descends to the target position and needs to remain stationary, the passive control plate 406 is reset, causing the sealing plug 405 to re-close the guide hole 402. At the same time, the angle adjustment motor 204 is started, driving the limiting arc ring 407 to rotate through the transmission rod 213, so that the flow limiting column 404 is in an adjustable state. At this time, when the lifting cylinder 103 stops working, the pressure on the side of the seepage plate 401 away from the lifting cylinder 103 drops rapidly, while the pressure in the buffer chamber on the other side is higher than that in the corresponding pressure chamber for a short time due to the inertia of the liquid, thereby pushing the flow limiting column 404 to produce displacement. Since the flow gap between the flow limiting column 404 and the seepage hole 403 is a preset structural parameter, the hydraulic medium can only be gradually balanced in a restricted flow form, thereby achieving slow release and stable maintenance of pressure, avoiding impact or displacement of the steel box girder. When the steel box girder needs to be adjusted laterally, the push cylinder 101 is first controlled to work, so that the push column 106 extends outward and pushes the center beam 104 to move along the slide rail 2. When the push column 106 reaches its stroke limit, if the position still needs to be adjusted, the internal pressure of the push cylinder 101 is gradually reduced. Since the push column 106 and the center beam 104 are detachable, when the push column 106 reaches its stroke limit, the flow channel is switched through the hydraulic control system, so that the rod chamber of the push cylinder 101 is filled with oil to generate a contraction force. Under the release of the pushing force and the drive of the contraction force, the push cylinder 101 overcomes the friction between the support plate 102 and the slide rail 2 and moves back smoothly along the slide rail 2 towards the push column 106 to prepare for the next stage of pushing. During this process, the passive rod 111 gradually extends relative to the push cylinder 101. As the passive rod 111 extends, the triangular plate 110 connected to its end enters the locking block 108 and, under the action of the inclined guide surface, drives the locking block 108 to overcome the elastic force of the elastic element and move upward, so that it disengages from the lateral limiting structure of the slide rail 2, thereby releasing the locking state between the support plate 102 and the slide rail 2, ensuring that the push cylinder 101 can smoothly complete the return and reset. When the push cylinder 101 moves back to the predetermined position, pressure is applied to its interior again, driving the push column 106 to extend outward again. At the same time, the triangular plate 110 moves away from the locking block 108 along with the passive rod 111. The locking block 108 resets downward under the action of the elastic element and re-abuts against the lateral limiting structure of the slide rail 2, thereby locking the position of the support plate 102 again. Through the above cycle process, the step-by-step advancement and precise lateral adjustment of the steel box girder on the slide rail 2 are realized. When it is necessary to continue raising the height of the steel box girder, the driving ring 210 drives the sliding plate 208 to move, causing the passive plate 406 to shift, thereby causing the sealing plug 405 to disengage from the guide hole 402 again, restoring the guide channel, and allowing the hydraulic medium to flow smoothly again, thus cooperating with the lifting cylinder 103 to complete the smooth lifting of the steel box girder again.

[0025] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A beam lowering device for large-tonnage steel box girders spanning railways, comprising a frame (1), characterized in that: The frame (1) is fixedly mounted with a slide rail (2) along the length of the frame (1) to provide guidance and bearing base for each moving part. The frame (1) is symmetrically arranged with two lifting cylinders (103) inside. The two lifting cylinders (103) are fixedly connected by a central beam (104) to form an integral force-bearing structure and ensure synchronicity and stability during the lifting process. Each lifting cylinder (103) has a vertically sliding lifting column (105) at its upper end. The upper end of the lifting column (105) is used to support the bottom of the steel box girder. When the pressure inside the lifting cylinder (103) increases, the lifting column (105) moves upward with the increase of pressure, thereby lifting the steel box girder smoothly. The center beam (104) is symmetrically provided with two sets of buffer components. The buffer components include a buffer plug (206). The buffer plug (206) is slidably installed inside the buffer tube (201). The buffer plug (206) divides the inner cavity of the buffer tube (201) into a first pressure chamber and a second buffer chamber.

2. The beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 1, characterized in that: The bottom end of the lifting cylinder (103) is slidably connected to the upper surface of the slide rail (2), so that the lifting cylinder (103) and its upper structure can be adjusted along the slide rail (2) to achieve lateral fine adjustment and alignment of the steel box girder during the beam lowering process. A support plate (102) is slidably installed on the surface of the slide rail (2), and a push column (106) is fixedly installed on the upper end of the support plate (102). The push column (106) is set along the extension direction of the slide rail (2).

3. The beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 2, characterized in that: The upper end of the support plate (102) is fixedly installed with a limit box (107), and the inner end of the limit box (107) is provided with a locking block (108). The bottom end of the locking block (108) abuts against the crossbeam on the surface of the slide rail (2).

4. The beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 1, characterized in that: Two buffer tubes (201) are fixedly installed with control cylinders (203) at their close ends. The buffer tubes (201) are fixedly connected to the lifting cylinder (103). A passive ring (205) is movably installed inside the control cylinder (203). A central rod (207) is fixedly installed on the surface of the passive ring (205). The central rod (207) extends axially and passes through the corresponding buffer tube (201). A seepage plate (401) is slidably installed on the inner end of the buffer plug (206), and the seepage plate (401) is fixedly connected to the central rod (207), so that the movement of the buffer plug (206) can be synchronously transmitted to the passive ring (205) through the central rod (207).

5. The beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 4, characterized in that: A passive disk (406) is provided between the seepage disk (401) and the central rod (207). The passive disk (406) is coaxially arranged with the central rod (207). The surface of the seepage disk (401) is provided with a plurality of guide holes (402) and seepage holes (403) distributed in a ring. A plurality of sealing plugs (405) are fixedly installed at one end of the passive disk (406) away from the central rod (207). The plurality of sealing plugs (405) are provided in a one-to-one correspondence with the corresponding guide holes (402) for selectively blocking or opening the guide holes (402).

6. The beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 5, characterized in that: Multiple flow-limiting columns (404) are provided through the surface of the passive disk (406). The flow-limiting columns (404) are respectively inserted into the corresponding seepage holes (403). Multiple sliding plates (208) are slidably installed on the outer surface of the central rod (207). The multiple sliding plates (208) are evenly distributed in a ring and are fixedly connected to the passive disk (406).

7. The beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 6, characterized in that: The control cylinder (203) is coaxially mounted with a driving ring (210) and a passive sleeve (211). The passive sleeve (211) and the driving ring (210) are on the same axis and are fixedly connected to multiple sliding plates (208). A transmission rod (213) is provided through the center rod (207). A limit arc ring (407) is rotatably mounted on one end of the center rod (207) near the seepage plate (401). A rectangular hole is provided on the outer surface of the center rod (207).

8. The beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 7, characterized in that: The surface of the limiting arc ring (407) is provided with multiple inclined notches in the circumferential direction. The inclined surface of each inclined notch is in contact with the end of the corresponding flow limiting column (404). The end of the flow limiting column (404) near the limiting arc ring (407) is provided with a slope structure that matches the inclined notch, so as to enhance the contact fit and improve the transmission stability. The outer surface of the buffer plug (206) is provided with a sealing ring (301). A support spring (302) is provided between the sealing ring (301) and the buffer plug (206). The surface of the buffer plug (206) is provided with multiple through block (303) mounting positions. Each through block (303) is provided with a guide groove (304). The side of the seepage plate (401) near the center rod (207) is provided with a drive ring (408).

9. A beam lowering device for a large-tonnage steel box girder spanning a railway as described in claim 8, characterized in that: The conical surface of the drive ring (408) contacts the through block (303), pushing the through block (303) to move away from the buffer plug (206). The through groove (304) on the through block (303) connects the inner space of the sealing ring (301) with the inner space of the buffer plug (206).

10. A method of using a beam-lowering device for a large-tonnage steel box girder spanning a railway, applicable to any one of claims 1-9, characterized in that... Includes the following steps: S1: Move the frame (1) to the predetermined position under the steel box girder, complete the overall alignment through the slide rail (2), and then control the lifting cylinder (103) to work so that the lifting column (105) extends upward and abuts against the bottom of the steel box girder to support the steel box girder. On this basis, by adjusting the internal pressure of the lifting cylinder (103), the lifting column (105) slowly falls back, thereby driving the steel box girder to be lowered smoothly. S2: During the lowering of the steel box girder, the electric push rod (209) drives the drive ring (210) to rotate. Under the action of its inclined structure, the passive sleeve (211) and sliding plate (208) move axially along the central rod (207), thereby causing the passive disc (406) to be displaced. At this time, the sealing plug (405) is disengaged from the guide hole (402), the guide channel is opened, and the hydraulic medium can flow rapidly in the buffer pipe (201) to meet the flow requirements when the steel box girder is continuously lowered, and improve the stability of the lowering process. S3: When the steel box girder descends to the target position and needs to remain stationary, the passive control disc (406) is reset, causing the sealing plug (405) to re-close the guide hole (402). At the same time, the angle adjustment motor (204) is started, and the limiting arc ring (407) is driven to rotate through the transmission rod (213), so that the flow limiting column (404) is in an adjustable state. At this time, when the lifting cylinder (103) stops working, the pressure on the side of the seepage plate (401) away from the lifting cylinder (103) drops rapidly, while the pressure in the buffer chamber on the other side is higher than that in the corresponding pressure chamber for a short time due to the inertia of the liquid, thereby pushing the flow limiting column (404) to produce displacement. Since the flow gap between the flow limiting column (404) and the seepage hole (403) is a preset structural parameter, the hydraulic medium can only be gradually balanced in a restricted flow form, thereby realizing the slow release and stable maintenance of pressure, and avoiding impact or displacement of the steel box girder.

Images